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Tuna be, or not tuna be : using catch data to observe the ecological impacts of commercial tuna fisheries… Schiller, Laurenne Louise 2014

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TUNA	  BE,	  OR	  NOT	  TUNA	  BE:	  USING	  CATCH	  DATA	  TO	  OBSERVE	  THE	  ECOLOGICAL	  IMPACTS	  OF	  COMMERCIAL	  TUNA	  FISHERIES	  IN	  THE	  PACIFIC	  OCEAN	  AT	  VARYING	  SPATIAL	  SCALES	  by	  Laurenne	  Louise	  Schiller	  B.Sc.	  (Hons.),	  University	  of	  Guelph,	  2010	  A	  THESIS	  SUBMITTED	  IN	  PARTIAL	  FULFILLMENT	  OF	  THE	  REQUIREMENTS	  FOR	  THE	  DEGREE	  OF	  MASTER	  OF	  SCIENCE	  in	  The	  Faculty	  of	  Graduate	  and	  Postdoctoral	  Studies	  (Zoology)	  THE	  UNIVERSITY	  OF	  BRITISH	  COLUMBIA	  (Vancouver)	  August	  2014	  ©	  Laurenne	  Louise	  Schiller,	  2014ii	  ABSTRACT	  Tuna	  are	  arguably	   the	  world’s	  most	  valuable,	  versatile,	  yet	  vulnerable	   fishes.	  With	  current	   landings	   over	   4	  million	   tonnes	   annually,	   all	   species	   of	   tuna	   from	   all	   three	  major	  ocean	   basins	   are	   caught,	   traded,	   and	   consumed	   at	   various	   intensities	   around	   the	   globe.	  Understanding	   the	   implications	   of	   such	   an	   extensive	   industry	   is	   paramount	   to	   protecting	  the	  long-­‐term	  health	  and	  sustainability	  of	  both	  the	  tuna	  fisheries	  as	  well	  as	  the	  ecosystems	  in	  which	  they	  operate.	  	  Given	   that	   the	   Pacific	   Ocean	   accounts	   for	   roughly	   two-­‐thirds	   of	   the	   global	  commercial	  tuna	  catch,	  this	  thesis	  assesses	  the	  trends	  and	  ecological	  impacts	  of	  commercial	  tuna	   fishing	   at	   both	   the	   artisanal	   and	   industrial	   scale	   in	   this	   ocean.	   To	   observe	   the	  importance	   of	   tuna	   fisheries	   at	   a	   local	   scale,	   a	   case	   study	   of	   the	   Galápagos	   Islands	   is	  presented.	  In	  this	  context,	  it	  was	  observed	  that	  over-­‐fishing	  and	  the	  subsequent	  depletion	  of	  large,	  low	  fecund	  serranids	  has	  resulted	  in	  a	  high	  level	  of	  ‘fishing	  down’	  within	  the	  near-­‐shore	  ecosystem.	  Consequently,	  as	  fishers	  are	  forced	  to	  expand	  to	  regions	  off-­‐shore,	  tuna	  and	  coastal	  scombrids	  are	  becoming	  increasingly	  targeted.	  With	  regard	  to	  industrial	  fishing,	  tuna	   vessels	   (especially	   distant-­‐water	   longliners)	   are	   known	   to	   generate	   a	   substantial	  amount	  of	  associated	  bycatch	  and	  discards.	  	  The	   second	   component	   of	   this	   thesis	   quantified	   the	   amount	   of	   bycatch	   (retained	  and	   discarded)	   generated	   by	   Pacific	   tuna	   fishing	   fleets	   from	   1950	   to	   2010.	   Unreported	  retained	  bycatch	  amounted	  to	  1.4	  million	  t;	  the	  total	  discarded	  catch	  associated	  with	  tuna	  fishing	  was	   3.6	  million	   t	   of	   target	   species	   and	   7.9	  million	   t	   of	   non-­‐target	   species;	   sharks	  iii	  were	   the	   most	   commonly	   discarded	   species.	   These	   totals	   represent	   about	   14%	   of	   the	  reported	  landings	  during	  this	  time.	  	  Lastly,	   an	   analysis	   of	   the	   applicability	   of	   the	   ‘Catch-­‐MSY’	   method	   developed	   by	  Martell	   and	   Froese	   (2012)	   in	   the	   context	   of	   large	   pelagic	   fishes	   is	   presented.	   It	   was	  observed	  that	  this	  method	  produces	  MSY	  estimates	  highly	  correlated	  to	  those	  produced	  by	  complete	  stock	  assessments.	  Collectively,	  the	  results	  of	  this	  thesis	  suggest	  that	  the	  tools	  to	  adequately	   manage	   tuna	   exist;	   however,	   proper	   data	   collection	   is	   rare,	   and	   the	  implementation	   of	   adequate	   sustainable	   fishing	   measures	   by	   fisheries	   managers	   is	   still	  wanting.	  iv	  PREFACE	  With	  the	  exception	  of	  the	  bookend	  Chapters	  1	  and	  5,	  each	  chapter	  in	  this	  thesis	  has	  been	  prepared	   as	   a	   stand-­‐alone	   manuscript.	   All	   background	   research,	   data	   acquisition	   and	  analyses,	  and	  writing	  included	  in	  this	  thesis	  were	  completed	  by	  myself.	  However,	  I	  received	  guidance	  with	   the	   conceptualization	   of	   these	   chapters	   and	   applicable	  methodology	   from	  my	  supervisor,	  Daniel	  Pauly,	  as	  well	  as	  other	  colleagues.	  These	  collaborations	  are	  discussed	  below.	  A	  version	  of	  Chapter	  2	  has	  been	  published	  and	  I	  am	  the	  lead	  author	  on	  this	  work.	  As	  such,	  I	  assumed	   primary	   responsibility	   for	   its	   design,	   analysis,	   and	   completion.	   Nonetheless,	   I	  received	   invaluable	  contributions	  with	   regard	   to	   the	  context	  and	  historical	  background	  of	  Galápagos	   fisheries	   from	  my	   co-­‐authors	   Juan	   Jose	   Alava,	   Jack	   Grove,	   Günther	   Reck,	   and	  Daniel	  Pauly.	  These	  authors,	  as	  well	  as	  the	  Charles	  Darwin	  Foundation,	  also	  provided	  some	  of	  the	  data	  used	  for	  the	  analyses	  in	  this	  chapter.	  Chapter	  3	  is	  part	  of	  a	  larger	  global	  analysis	  of	  the	  impacts	  of	  commercial	  tuna	  fisheries	  that	  will	   be	   incorporated	   into	   the	   Sea	  Around	  Us	  Project	   global	   fisheries	   database	   and	   future	  publications.	   As	   such,	   Daniel	   Pauly	   provided	   guidance	   with	   regard	   to	   some	   of	   the	  methodology	  and,	  upon	  the	  completion	  of	  the	  data	  analyses,	  I	  worked	  closely	  with	  Frédéric	  Le	   Manach	   and	   Andrés	   Cisneros	   Montemeyor	   to	   ensure	   my	   results	   were	   properly	  formatted	  and	  transferable	  to	  the	  main	  database.	  v	  The	  overarching	  concept	  and	  methodology	  used	  in	  Chapter	  4	  was	  designed	  by	  Steve	  Martell	  and	   Rainer	   Froese	   and	   is	   discussed	   in	   detail	   their	   2012	   paper,	   ‘A	   simple	   method	   for	  estimating	  MSY	   from	   catch	   and	   resilience’.	  Daniel	   Pauly	   suggested	   the	   application	   of	   the	  Catch-­‐MSY	  method	  for	  tuna,	  and	  assisted	  me	  in	  its	  conceptualization	  in	  the	  context	  of	  this	  thesis.	  	  vi	  TABLE	  OF	  CONTENTS	  ABSTRACT	  ........................................................................................................................	  ii	  PREFACE	  ..........................................................................................................................	  iv	  TABLE	  OF	  CONTENTS	  .......................................................................................................	  vi	  LIST	  OF	  TABLES	  ...............................................................................................................	  viii	  LIST	  OF	  FIGURES	  ...............................................................................................................	  ix	  ACKNOWLEDGEMENTS	  .....................................................................................................	  x	  1	   |	  VALUABLE,	  VERSATILE,	  VULNERABLE	  .......................................................................	  1	  The	  rise	  of	  seafashion	  ......................................................................................................	  2	  Cat	  food	  to	  cult	  food	  ........................................................................................................	  4	  Quantifying	  the	  world’s	  appetite	  .....................................................................................	  6	  Research	  objectives	  and	  purpose	  ....................................................................................	  7	  2	   |	  THE	  DEMISE	  OF	  DARWIN’S	  FISHES	  ..........................................................................	  10	  INTRODUCTION	  ..................................................................................................................	  11	  Island	  geography	  and	  demographics	  .............................................................................	  11	  Overview	  of	  Galápagos	  fisheries	  ....................................................................................	  13	  Artisanal	  fisheries	  ...........................................................................................................	  15	  Industrial	  fishery	  for	  tuna	  ...............................................................................................	  20	  Shark	  fishing	  ...................................................................................................................	  21	  Sportfishing	  ....................................................................................................................	  22	  METHODS	  ...........................................................................................................................	  23	  Local	  consumption	  .........................................................................................................	  23	  Bacalao	  and	  finfish	  .........................................................................................................	  24	  Sea	  cucumber	  .................................................................................................................	  25	  Spiny	  and	  slipper	  lobster	  ................................................................................................	  26	  Tuna	  (industrial)	  .............................................................................................................	  27	  Sharks	  .............................................................................................................................	  27	  Trophic	  level	  analysis	  .....................................................................................................	  28	  RESULTS	  AND	  DISCUSSION	  .................................................................................................	  30	  Local	  consumption	  .........................................................................................................	  31	  Bacalao	  and	  finfish	  .........................................................................................................	  32	  Sea	  cucumber	  .................................................................................................................	  33	  Spiny	  and	  slipper	  lobster	  ................................................................................................	  35	  Tuna	  (industrial)	  .............................................................................................................	  37	  Sharks	  .............................................................................................................................	  38	  Trophic	  level	  analysis	  .....................................................................................................	  41	  CONCLUSIONS	  ....................................................................................................................	  43	  3	   |	  LOST	  GIANTS	  OF	  THE	  PACIFIC	  .................................................................................	  46	  INTRODUCTION	  ..................................................................................................................	  47	  Large	  pelagic	  fishes	  of	  the	  Pacific	  Ocean	  .......................................................................	  47	  vii	  Industrial	  tuna	  fisheries	  of	  the	  Pacific	  Ocean	  .................................................................	  50	  Small-­‐scale	  tuna	  fisheries	  of	  the	  WPO	  ...........................................................................	  55	  Bycatch	  associated	  with	  tuna	  fisheries	  ..........................................................................	  56	  Stock	  management	  and	  monitoring	  ...............................................................................	  60	  Purpose	  of	  study	  ............................................................................................................	  63	  METHODS	  ...........................................................................................................................	  64	  Baseline	  species	  catch	  data	  ............................................................................................	  64	  Unreported	  target	  tuna	  landings	  ...................................................................................	  65	  Accounting	  for	  regional	  differences	  of	  reported	  r-­‐bycatch	  ...........................................	  65	  Discarded	  catch	  of	  industrial	  fleets	  ................................................................................	  67	  Estimating	  artisanal	  bycatch	  and	  discards	  .....................................................................	  68	  IATTC	  and	  WCPFC	  overlap	  zone	  .....................................................................................	  69	  RESULTS	  ..............................................................................................................................	  71	  Total	  retained	  bycatch	  ...................................................................................................	  72	  Discarded	  target	  species	  and	  discarded	  bycatch	  ...........................................................	  73	  DISCUSSION	  ........................................................................................................................	  75	  Unreported	  landings	  and	  illegal	  tuna	  fishing	  .................................................................	  76	  Unreported	  discards	  ......................................................................................................	  78	  Composition	  of	  discarded	  bycatch	  .................................................................................	  80	  Impacts	  of	  tuna	  fisheries	  on	  air-­‐breathing	  marine	  animals	  ...........................................	  85	  Bycatch	  mitigation	  efforts	  ..............................................................................................	  86	  Limitations	  of	  study	  ........................................................................................................	  88	  CONCLUSIONS	  ....................................................................................................................	  90	  4	   |	  THE	  BEAUTIFUL	  SIMPLICITY	  OF	  THE	  THING	  .............................................................	  92	  INTRODUCTION	  ..................................................................................................................	  93	  The	  role	  of	  stock	  assessments	  ........................................................................................	  93	  Population	  dynamics	  of	  fish	  stocks	  ................................................................................	  94	  The	  Schaefer	  production	  model	  .....................................................................................	  96	  The	  Catch-­‐MSY	  method	  .................................................................................................	  99	  Purpose	  of	  study	  ..........................................................................................................	  101	  METHODS	  .........................................................................................................................	  102	  Catch	  data	  ....................................................................................................................	  102	  Catch-­‐to-­‐MSY	  analysis	  ..................................................................................................	  103	  RESULTS	  ............................................................................................................................	  104	  DISCUSSION	  ......................................................................................................................	  106	  Accuracy	  of	  the	  Catch-­‐MSY	  algorithm	  for	  certain	  stocks	  .............................................	  106	  CONCLUSIONS	  ..................................................................................................................	  108	  5	   |	  THE	  PRIVILEGE	  TO	  KNOW	  .....................................................................................	  110	  …The	  Duty	  to	  Act	  ..........................................................................................................	  111Take	  arms	  against	  a	  sea	  of	  troubles	  .............................................................................	  113	  REFERENCES	  .................................................................................................................	  119	  APPENDIX	  .....................................................................................................................	  142	  viii	  LIST	  OF	  TABLES	  Table	  2-­‐1.	  Geography	  and	  fishing	  demographics	  of	  the	  Galápagos	  Islands.	  .........................	  12	  Table	  2-­‐2.	  Trophic	  level	  (TL)	  of	  commonly	  caught	  finfish	  and	  invertebrates	  of	  the	  Galápagos	  Islands.	  ...........................................................................................................................	  29	  Table	  3-­‐1.	  Target	  species,	  associated	  primary	  gears	  and	  sources	  of	  data	  for	  the	  fisheries	  in	  the	  Pacific	  Ocean.	  ...........................................................................................................	  64	  Table	  3-­‐2.	  Reconstructed	  unreported	  catch	  of	  southern	  bluefin	  in	  the	  Pacific	  Ocean.	  .........	  65	  Table	  3-­‐3.	  Non-­‐target	  species	  r-­‐bycatch	  as	  reported	  by	  the	  Pacific	  RFMOs.	  CCSBT	  does	  not	  report	  any	  r-­‐bycatch.	  .....................................................................................................	  66	  Table	  3-­‐4.	  R-­‐bycatch	  associated	  with	  certain	  WCPFC	  Pacific	  Ocean	  small-­‐scale	  fleets.	  Species	  breakdowns	  were	  also	  estimated	  based	  on	  these	  sources.	  ...........................................	  70	  Table	  4-­‐1.	  Default	  values	  for	  the	  maximum	  intrinsic	  rate	  of	  population	  growth	  based	  on	  resilience	  classifications	  (very	  low	  to	  high)	  from	  FishBase.	  .........................................	  100	  Table	  4-­‐2.	  Default	  values	  for	  initial	  and	  final	  biomasses.	  ....................................................	  100	  Table	  4-­‐3.	  Input	  resilience	  classifications	  from	  FishBase	  and	  mean	  MSY	  predictions	  from	  the	  stock	  assessment	  and	  Martell	  and	  Froese	  method	  (2012).	  .........................................	  104	  ix	  LIST	  OF	  FIGURES	  Figure	  2-­‐1.	  Reconstructed	  Galápagos	  artisanal	  finfish	  catch	  (1950-­‐2010),	  by	  family.	  ...........	  32	  Figure	  2-­‐2.	  Total	  reconstructed	  sea	  cucumber	  catch	  for	  the	  Galápagos	  archipelago,	  1950-­‐2010.	  ..............................................................................................................................	  34	  Figure	  2-­‐3.	  Reconstructed	  catch	  of	  spiny	  and	  slipper	  lobsters	  for	  the	  Galápagos,	  1950-­‐2010.	  .......................................................................................................................................	  37	  Figure	  2-­‐5.	  Changes	  in	  mean	  trophic	  level	  (TL)	  of	  the	  artisanal	  catch	  in	  the	  Galápagos	  Islands.	  ...........................................................................................................................	  42	  Figure	  3-­‐1.	  Boundaries	  of	  jurisdiction	  of	  the	  Regional	  Fisheries	  Management	  Organizations	  (RFMOs)	  responsible	  for	  managing	  tuna	  ........................................................................	  62	  Figure	  3-­‐2.	  Total	  reconstructed	  catch	  of	  tunas	  and	  associated	  bycatch	  and	  dicards	  in	  the	  Pacific	  Ocean	  from	  1950-­‐2010.	  ......................................................................................	  72	  Figure	  3-­‐3.	  Reconstructed	  retained	  bycatch	  of	  species	  associated	  with	  Pacific	  Ocean	  tuna	  fleets.	  .............................................................................................................................	  73	  Figure	  3-­‐4.	  Species	  composition	  of	  d-­‐bycatch	  between	  1950-­‐2010.	  .....................................	  74	  Figure	  3-­‐5.	  Discards	  of	  target	  species	  in	  the	  Pacific	  Ocean	  between	  1950-­‐2010.	  .................	  74	  Figure	  4-­‐1.	  Logistic	  growth	  curve	  of	  a	  hypothetical	  fish	  population.	  .....................................	  97	  Figure	  4-­‐2.	  Schaefer’s	  surplus-­‐production	  function.	  ..............................................................	  98	  Figure	  4-­‐3.	  Initial	  ranges	  of	  𝑟	  and	  𝑘,	  and	  the	  𝑟−	  𝑘	  combinations	  that	  are	  compatible	  with	  the	  time	  series	  of	  catch	  (n=	  2,897)	  for	  albacore	  tuna	  in	  the	  South	  Pacific	  Ocean.	  ............	  101	  Figure	  4-­‐4.	  Comparison	  of	  MSY	  estimates	  (log	  t)	  using	  stock	  assessment	  and	  Martell	  and	  Froese	  (2012)	  Catch-­‐MSY	  method.	  ..............................................................................	  105	  x	  ACKNOWLEDGEMENTS	  First	   and	   foremost,	   I	   express	   sincere	   gratitude	   to	   my	   supervisor,	   Daniel	   Pauly,	   for	   his	  mentorship,	   guidance,	   patience,	   and	   support.	   Some	   people	   are	   lucky	   to	   have	   a	   good	  scientist	   for	   their	   supervisor;	   I	   was	   lucky	   to	   have	   a	   great	   scientist—and	   an	   equally	   great	  human	  being—who	  taught	  me	  as	  much	  about	  fisheries	  as	  he	  did	  about	  life.	  	  This	   thesis	   could	   not	   have	   been	   properly	   completed	   without	   the	   helpful	   advice	   of	   my	  committee	   members,	   Rashid	   Sumaila	   and	   William	   Cheung;	   I	   thank	   them	   both	   for	   their	  interdisciplinary	   insights.	   I	  also	   thank	  The	  Pew	  Charitable	  Trusts	   for	  providing	   the	   funding	  for	  this	  research.	  On	  a	  personal	  note,	  I	  express	  gratitude	  beyond	  measure	  to	  Wilf	  Swartz	  for	  his	  unwavering	  patience	  and	  encouragement	  since	  I	  first	  arrived	  at	  UBC.	  My	  sincere	  appreciation	  also	  goes	  to	   Fred	   Le	  Manach	   for	   never	   failing	   to	  make	  me	   laugh	   and	   share	   in	  my	   sarcasm,	   Kyrstn	  Zylich	   for	  her	   innate	  ability	   to	  handle	  my	  perfectionism,	  Bea	  Francisco	   for	  keeping	  me	  on	  my	   toes	   (literally),	   and	   Lucas	   Brotz	   for	   making	   sure	   I	   always	   kept	   life	   in	   perspective.	   I	  additionally	  extend	  my	  gratitude	  to	  Doug	  Fudge,	  who	  first	  inspired	  me	  to	  study	  tuna.	  I	  am	  additionally	  indebted	  to	  several	  people	  at	  the	  UBC	  Fisheries	  Centre	  (past	  and	  present)	  for	   their	   academic	   input	   and	   assistance,	   but	  mostly	   for	   their	   friendship.	   In	   this	   regard,	   I	  thank	  Lisa	  Boonzaier,	  Elize	  Bultel,	  Andrés	  Cisneros	  Montemayor,	  Mathieu	  Colléter,	  Morgan	  Davies,	  Beau	  Doherty,	  Andrea	  Haas,	  Mike	  Hawkshaw,	  Claire	  Hornby,	  Alastair	  Lindop,	  Yoshi	  Ota,	   Robin	   Ramdeen,	   and	   Pamela	   Rosenbaum.	  My	   work	   is	   just	   a	   small	   piece	   of	   a	   huge	  global	  puzzle,	  and	  I	  thank	  the	  Sea	  Around	  Us	  Project	  for	  giving	  it	  a	  home.	  	  Lastly,	  thank	  you	  to	  all	  my	  family	  and	  friends	  who	  patiently	  listened	  whenever	  I	  attempted	  to	   share	   my	   knowledge	   of	   fisheries	   and	   sustainable	   seafood.	   I	   hope	   that⎯	   on	   some	  level⎯my	  tuna	  talk	  was	  retained.	  xi	  For	  Nana,	  who	  first	  encouraged	  me	  to	  love	  the	  creatures	  of	  the	  sea.	  And	  for	  Mom	  and	  Dad,	  who	  enabled	  me	  to	  study	  them.	  xii	  What	  caught	  my	  eye	  was	  a	   faint	  chevron	  bulging	  ever	   so	  slightly	   from	  the	  molten,	  glassy	  sea,	  fifty	  yards	  from	  where	  I	  sat	  adrift.	  As	  I	  rose	  to	  my	  feet	  to	  study	  it,	  the	  chevron	  grew	  to	  a	  distinct	  wake.	  A	  wake	  without	  a	  boat.	  The	  wake	  ran	  along	  the	  surface	   for	  a	   few	  seconds,	  accelerated,	   and	   exploded	   like	   a	   revelation.	   A	   giant	   bluefin	   tuna,	   among	   the	   largest	   and	  most	  magnificent	  of	  animals,	  hung	  suspended	  for	  a	  long,	  riveting	  moment,	  emblazoned	  and	  backlit	  like	  a	  saber-­‐fined	  warrior	  from	  another	  world,	  until	  its	  six-­‐hundred	  pounds	  of	  muscle	  crashed	  into	  the	  ocean	  like	  a	  boulder	  falling	  from	  the	  sky.	  -­‐Carl	  Safina,	  Song	  for	  the	  Blue	  Ocean	  1	  1 |	  VALUABLE,	  VERSATILE,	  VULNERABLE	  A	  rock	  pile	  ceases	  to	  be	  a	  rock	  pile	  the	  moment	  a	  single	  man	  contemplates	   it,	  bearing	  within	  him	  the	  image	  of	  a	  cathedral.	  -­‐Antoine	  de	  Saint-­‐Exupéry,	  The	  Little	  Prince	  	  2	  The	  rise	  of	  seafashion	  At	  present,	  Earth	   is	  home	   to	  an	  estimated	  seven	  billion	  people⎯	   a	   substantial	  increase	   from	   sixty	   years	   ago,	   when	   the	   human	   population	   was	   a	  modest	   2.5	   billion	  (World	   Bank	   2011).	   In	   conjunction	   with	   this	   exponential	   increase	   in	   population,	   has	  come	  the	  emergence	  of	  the	  age	  of	  globalization.	  While	  many	  people	  tend	  to	  think	  that	  this	   international	   assimilation	   is	   the	   byproduct	   of	   either	   technological	   innovation,	  improvements	   in	   production	   and	   transport	   efficiency,	   or	   the	   onset	   of	   free	   trade,	   it	   is	  actually	   advancements	   in	   all	   of	   these	   areas	   that	   have	   contributed	   to	   a	   dramatic	  psychological	  shift	  in	  the	  developed	  world’s	  perception	  of	  what	  constitutes	  an	  essential	  lifestyle	  requirement.	  Fish	   is	   the	   last	   remaining	   wild	   animal	   protein	   that	   can	   be	   obtained	   by	   most	  countries.	   The	  most	   recent	   Status	  of	   Fisheries	   and	  Aquaculture	   (SOFIA)	  Report	  by	   the	  Food	  and	  Agricultural	  Organization	  of	  the	  United	  Nations	  (FAO)	  estimated	  that,	  in	  2011,	  78	  million	   tonnes	  of	   seafood	  was	   removed	   from	   the	  ocean;	  nearly	  half	  of	   the	  world’s	  population	   depends	  on	  marine	   resources	   for	   25%	  of	   their	   annual	   protein	   intake	   (FAO	  2012).	  While	  these	  values	  may	  seem	  to	  reflect	  the	  world’s	  social	  demographics,	  perhaps	  the	  most	   disconcerting	   observation	   from	   the	   same	   report	   is	   that	   the	   total	   global	   per	  capita	   consumption	   of	   fish	   has	   nearly	   doubled	   in	   the	   last	   fifty	   years:	   from	   9.9	   kg-­‐1person-­‐1	  ⋅	  year-­‐1	  in	  the	  1960s	  to	  18.4	  kg-­‐1	  person-­‐1	  ⋅ year-­‐1	  	  in	  2009.	  	  In	  developed	  countries,	   the	  distinction	  of	  high-­‐end	  seafood	   (including	  sushi)	  as	  some	   of	   the	   trendiest	   cuisine	   available	   is	   due	   largely	   to	   the	   clever	   marketing	   of	   its	  putative	   cardiac	   health	   benefits	   (Jenkins	   et	   al.	   2009),	   and	   the	   emergence	   of	   the	   red-­‐3	  meat	  conscious	  consumer.	  Why	  eat	  a	  500-­‐calorie	  sirloin	  steak	  when	  you	  could	  eat	  the	  same	  size	  piece	  of	  halibut	  at	  only	  275	  calories	  with	  not	  only	  less	  fat,	  but	  good	  fat?	  While	  two	  servings	  of	  fish	  per	  week	  appears	  sufficient	  for	  addressing	  one’s	  omerga-­‐3	  fatty	  acid	  requirements	   (Kris-­‐Etherton	   et	   al.	   2002)—not	   to	  mention	   their	   availability	   from	  other	  sources,	   such	   as	   nuts—the	   per	   capita	   consumption	   statistics	   in	   developed	   countries	  suggest	  people	  are	  eating	  far	  more	  than	  that.	  Indeed,	  for	  many,	  even	  the	  basic	  notion	  of	  food	  has	  ascended	  through	  Maslow’s	  hierarchy	  to	  a	  point	  where	  it	  is	  no	  longer	  seen	  as	  a	  fundamental	  need,	  but	  as	  a	  status	  symbol	  instead.	  Especially	  in	  North	  America,	  seafood	  has	  become	  increasingly	  fashionable	  as	  a	  luxury	  meal	  choice.	  However,	  largely	  without	  public	   awareness,	   this	   increasing	   demand	   for	   fish	   has	   impacted	   the	   underlying	  ecological	   relationships	   within	   the	   marine	   environment	   and,	   unless	   management	  improves,	  it	  has	  the	  potential	  to	  affect	  fish	  species	  never	  before	  hunted	  (Sumaila	  et	  al.	  2010a).	  	  It	  may	  not	  seem	  like	  long	  ago,	  but	  looking	  back	  to	  the	  turn	  of	  the	  20th	  century,	  fishing	   fleets	  were	   largely	   restricted	   to	   regions	  near-­‐shore	  and	   their	   catch	  was	  mainly	  small,	   fast	   reproducing	   forage	   fish,	   such	  as	   sardines	  and	  herring	   (Roberts	  2007).	  Now,	  with	  coastal	  fish	  populations	  collapsing	  or	  becoming	  heavily	  depleted	  (Pauly	  et	  al.	  2002),	  technological	   advancements	   resulting	   in	   increased	   catchability	   (Fridman	   2009),	   and	  government	  subsidies	  allowing	  fisheries	  to	  switch	  target	  species	  and	  move	  farther	  and	  deeper	  offshore	  to	  acquire	  their	  catch	  (Pauly	  et	  al.	  2002;	  Sumaila	  et	  al.	  2010b;	  Swartz	  et	  al.	  2010a),	  the	  globalization	  of	  the	  seafood	  trade	  enables	  consumers	  of	  the	  developed	  world	   to	  eat	  nearly	  any	  species	  desired—regardless	  of	   their	  proximity	   to	   the	  ocean	   in	  4	  which	   it	  was	  caught	   (Swartz	  et	  al.	  2010b).	  And,	   instead	  of	   looking	  to	  cease	  the	   fishing	  pressure	   and	   rebuild	   depleted	   fisheries,	   people	   have	   instead	   expanded	   their	   horizons	  and	  palates,	  allowing	  a	  greater	  diversity	  of	  seafood	  to	  grace	  our	  plates.	  In	  short,	  we	  are	  running	   out	   of	   both	   places	   to	   fish	   and—much	   more	   importantly—out	   of	   the	   fish	  themselves.	  	  	   	  Cat	  food	  to	  cult	  food	  While	  canned	  skipjack	  and	  albacore	  tuna	  have	  been	  common,	  inexpensive	  staple	  food	   items	  for	  North	  Americans	  and	  Europeans	  since	  the	  1930s,	   fresh	  tuna	  was	  rarely	  sold	   or	   consumed.	   In	   fact,	   less	   than	   a	   century	   ago,	   Atlantic	   bluefin	   tuna	   (Thunnus	  thynnus)	   was	   not	   only	   abundant	   in	   the	   North	   Sea,	   but	   considered	   a	   nuisance	   by	  mackerel	  fishers	  because	  although	  it	  would	  frequently	  get	  caught	  in	  their	  nets,	  it	  had	  no	  commercial	  value	  other	  than	  as	  canned	  pet	  food	  (Pauly	  1995).	  Not	  until	  the	  late	  1970s,	  when	  trans-­‐continental	  commercial	  airlines	  started	  to	  transport	  these	  massive	  fish,	  did	  their	   flesh	   became	   a	   desirable	   commodity	   for	   sushi	   patrons	   abroad	   (Issenberg	   2007).	  Today,	  flash-­‐freeze	  capabilities	  enable	  fishers	  to	  transport	  their	  catch	  around	  the	  world	  without	  it	  spoiling:	  a	  tuna	  caught	  in	  Kiribati	  on	  a	  Wednesday	  can	  reach	  a	  dinner	  table	  in	  Tokyo	  by	  Thursday.	  To	  further	  promote	  the	  prestigious	  allure	  of	  this	  species,	  the	  sale	  of	  a	  bluefin	  tuna	  now	  marks	  the	  start	  of	  the	  calendar	  year	  at	  Tokyo’s	  Tsukiji	  fish	  market;	  a	  tradition	  that	  is	  quickly	  evolving	  to	  be	  a	  quest	  for	  publicity	  rather	  than	  quality	  seafood.	  It	   might	   sound	   surreal	   but,	   only	   thirty	   years	   after	   its	   introduction	   to	   Japanese	  5	  restaurants,	   a	   222	   kg	   Pacific	   cousin	   (Thunnus	   orientalis)	   of	   the	   very	   same	   North	   Sea	  nuisance	  tuna	  sold	  at	  Tsukiji	  for	  over	  ¥155	  million	  (US$1.78	  million)1.	  	  A	   similar	   status-­‐driven	   demand	   exists	   for	   shark	   fins.	   However,	   contrary	   to	   the	  world’s	  recent	  onset	  of	  a	  craving	  for	  bluefin	  tuna,	  sharkfin	  soup	  is	  a	  dish	  that	  has	  deep	  roots	   in	  Chinese	  culture.	  During	  the	  Sung	  dynasty	   (968	  AD),	   the	  Emperor	  often	  served	  sharkfin	   soup	   (as	   well	   as	   other	   marine	   delicacies)	   to	   his	   guests	   at	   banquets	   and	  ceremonies	  as	  a	  symbol	  of	  respect	  and	  wealth2;	  the	  importance	  and	  exclusivity	  of	  these	  foods	   has	   been	   retained	   to	   present	   day.	   However,	   unlike	   sea	   cucumbers	   and	   urchins	  (species	  that	  are	  also	  sought	  for	  aphrodisiac	  and	  ceremonial	  purposes),	  only	  a	  small	  part	  of	   the	   shark’s	  body	   (i.e.,	   the	   fins)	   is	  desired.	  As	   such,	  between	  90-­‐99%	  of	   the	   shark	   is	  wasted	   (often	  discarded	   at	   sea),	   since	   their	  meat	   fetches	   a	   significantly	   lower	  market	  price	  than	  their	  fins	  (Musick	  2005;	  Biery	  and	  Pauly	  2012).	  The	  demand	  for	  sharkfin	  soup	  is	   at	   an	   all-­‐time	   high,	   and	   although	   many	   countries	   have	   legislation	   banning	   finning	  practices,	   illicit	   shark	   fishing	   operations	   and	   bureaucratic	   loopholes	   allow	   finning	   to	  continue	  at	  a	  global	  scale	  (Jacquet	  et	  al.	  2008;	  Biery	  and	  Pauly	  2012).	  	  Despite	  the	  fact	  that	  all	  three	  species	  of	  bluefin	  are	  overfished	  (Boustany	  2011;	  CCSBT	   2011),	   and	   sharks	   are	   hunted	   only	   for	   their	   fins,	   people	   continue	   to	   demand	  these	  products;	  a	  quality	  piece	  of	  otoro3	  and	  a	  bowl	  of	  sharkfin	  soup	  now	  linger	  on	  the	  second	   highest	   level	   of	   necessity,	   where	   one	   searches	   for	   ways	   in	   which	   to	   publicly	  portray	   their	   social	   esteem	   and	   self	   worth.	   As	   such,	   it	   is	   this	   complex	   interaction	   of	  1From:	  http://www.bbc.co.uk/news/world-­‐asia-­‐20919306	  [accessed	  24	  February	  2014].	  2 From:	   http://www.sharktruth.com/learn/history-­‐of-­‐shark-­‐fin-­‐soup	   [accessed	   12	   May	   2014];	   some	  sources	  attribute	  this	  tradition	  to	  the	  Ming	  Dynasty	  (1368-­‐1644)	  instead.	  3The	  fattiest	  cut	  of	  bluefin	  tuna	  sashimi	  available	  (and	  typically	  the	  most	  expensive).	  	  	  6	  consumer	  preferences	  and	  demand,	  culture,	  market	  mechanisms	  and	  food	  availability,	  in	  addition	  to	  biological	  factors,	  that	  lead	  to	  the	  problem	  of	  overfishing	  illustrated	  in	  the	  case	  of	  tuna	  and	  sharks.	  Quantifying	  the	  world’s	  appetite	  At	   present,	   the	   FAO	   estimates	   that	   30%	   of	   the	   world’s	   fish	   stocks	   are	  overexploited	  (FAO	  2012).	  However,	  these	  values	  likely	  do	  not	  depict	  the	  true	  state	  of	  exploitation.	   Since	   1950,	   the	   FAO	   has	   collected	   annual	   fisheries	   landings	   from	   its	  member	  countries	  and	  these	  are	  compiled	  in	  their	  FishStat	  database	  (see	  www.fao.org).	  These	   statistics	   rely	   on	   the	   accuracy	   of	   reporting	   countries	   and,	   in	  many	   cases,	   refer	  primarily	   to	   commercial	   and	   large-­‐scale	   operations	   (Shimada	   1958;	   Castro	   2005).	  Consequently,	   smaller	   sector	   fishing	   (i.e.,	   subsistence,	   recreational,	   artisanal),	   illegal,	  and	   unreported	   catches	   (e.g.,	   bycatch	   and	   discards)	   are	   often	   overlooked	   or	   mis-­‐reported.	  This	  discrepancy	   is	   largely	  due	  to	  a	   lack	  of	   infrastructure	   for	  acquiring	   these	  data	  in	  developing	  countries	  (Caddy	  et	  al.	  1998;	  Bedoya	  2009)	  or,	  as	  is	  the	  case	  in	  some	  regions	   (e.g.,	   the	   Galápagos	   Islands),	   fishers	   may	   not	   even	   be	   required	   to	   record	   or	  report	  their	  catches	  (Hearn	  et	  al.	  2005).	  On	  the	  other	  end	  of	   the	  spectrum,	   industrial-­‐scale	  catches	  may	  be	  falsified	  in	  order	  to	  satisfy	  government	  officials	  (Watson	  and	  Pauly	  2001).	  Thus,	  the	  availability	  and	  accuracy	  of	  FAO	  catch	  data	  is	  highly	  varied	  by	  country	  and	  area,	  and,	  in	  many	  cases,	  landings	  are	  largely	  under-­‐reported.	  	  However,	   since	   catch	   statistics	   are	   a	   key	   component	   of	   many	   management	  publications	   and	  analyses	   (including	  both	   FAO’s	   SOFIA	   reports	   and	   smaller-­‐scale	   stock	  assessments),	   ensuring	   that	   the	   input	   data	   are	   accurate	   is	   of	   paramount	   importance.	  7	  Contrary	   to	   the	   largely	   accepted	   (but	   erroneous)	   belief	   that	  missing	   catch	   data	   for	   a	  given	   fishery	   or	   region	   means	   there	   was	   no	   catch	   (Pauly	   1998),	   the	   Sea	   Around	   Us	  Project	   at	   the	   University	   of	   British	   Columbia	   has	   attempted	   to	   acquire	   missing	  information	   and	   reconstruct	   catches	   for	   all	   countries	   and	   exclusive	   economic	   zones	  (EEZs)	   around	   the	   world.	   Using	   a	   variety	   of	   sources	   from	   the	   primary	   literature	   and	  national	   management	   agencies,	   as	   well	   as	   grey	   literature,	   more	   precise	   estimates	   of	  landings	  can	  be	  obtained	  and,	  when	  necessary,	  estimated	  using	  all	  available	  information	  (Zeller	   et	  al.	  2007).	  Through	   this	  undertaking,	   the	  Sea	  Around	  Us	   aims	   to	  quantify	   the	  total	   biomass	   of	   fish	   extracted	   from	   the	   oceans,	   and	   ultimately	   communicate	   the	  impacts	   of	   both	   small-­‐scale	   and	   industrial	   sized	   fisheries	   to	   a	   variety	   of	   stakeholders	  with	  the	  hope	  of	  mitigating	  their	  effects	  (Pauly	  2007).	  	  Research	  objectives	  and	  purpose	  From	  the	  polar	  seas	  to	  the	  tropical	  islands	  of	  the	  equator,	  no	  region	  of	  the	  world	  is	  left	  un-­‐fished	  (Swartz	  et	  al.	  2010a);	  at	  all	  spatial	  scales—from	  local	  to	  international—	  stocks	  are	  being	  overexploited	  to	  satisfy	  the	  world’s	  demand	  for	  seafood.	  The	  result	   is	  both	  a	  shift	   in	  the	  perception	  of	  what	  represents	  a	  healthy	  stock,	  as	  well	  as	  the	  actual	  species	   composition	   of	   the	   catch	   (Pauly	   1995;	   Ottolenghi	   2008a;	   Polovina	   and	  Woodworth-­‐Jefcoats	  2013).	  	  To	   understand	   the	   scale	   at	   which	   under-­‐reporting	   can	   occur	   at	   the	   artisanal	  level,	  as	  well	  as	  observe	  any	  trends	  in	  tuna	  landings	  at	  a	  local	  level	  (i.e.,	  within	  an	  EEZ),	  a	  regional	  analysis	  will	  be	  conducted	  through	  the	  historical	  review	  and	  subsequent	  catch	  reconstruction	  of	  the	  fisheries	  of	  the	  Galápagos	  Islands.	  Specifically,	  this	  reconstruction	  	   8	  will	  aim	  to	  give	  an	  accurate	  representation	  of	  the	  total	  marine	  fisheries	  landings	  from	  all	  sectors	  by	  both	  Galápagos	   fishers	  and	  fleets	   from	  mainland	  Ecuador	  within	  the	  EEZ	  of	  the	   Galápagos	   Islands	   between	   1950	   and	   2010.	   A	   secondary	   goal	   is,	   in	   view	   of	   the	  ongoing	  debate	  about	  the	  validity	  of	  the	  ‘fishing	  down’	  phenomenon	  (Pauly	  et	  al.	  1998;	  Caddy	  et	  al.	  1998;	  Pauly	  and	  Palomares	  2005;	  Essington	  et	  al.	  2006;	  Pauly,	  2010,	  2011;	  Branch	   et	  al.	   2011),	   to	   observe	  whether	   this	   trend	   is	   also	   occurring	   in	   the	  Galápagos	  Island	  artisanal	  fisheries	  and,	  if	  it	  is,	  at	  what	  intensity.	  	   	  	   Fish	   of	   the	   high	   seas	   contribute	   12-­‐15%	   of	   the	   total	   annual	   global	   catch	   by	  weight,	   and	   25%	   by	   value	   (Worm	   and	   Vanderzwaag	   2007).	   However,	   since	   these	  fisheries	   are	   far	   offshore	   and	   often	   out	   of	   range	   for	   proper	   observation	   and	   policy	  enforcement,	   they	   are	   also	   highly	   vulnerable	   to	   overexploitation.	   Presently,	   FAO	  statistics	  pertaining	  to	  high	  seas	  fisheries	  are	  largely	  dependent	  on	  data	  obtained	  from	  the	   world’s	   Regional	   Fisheries	   Management	   Organizations	   (RFMOs),	   which	   were	  previously	  supplied	  by	  member	  countries.	  While	  Pacific	  RFMOs	  are	  responsible	  for	  the	  management	  of	  certain	  tuna	  species,	  their	  available	  data	  pertaining	  to	  associated	  non-­‐target	  catches	  are	  incomplete.	  As	  such,	  this	  study	  will	  attempt	  to	  improve	  upon	  previous	  estimates	  of	  both	  bycatch	  and	  discards	  associated	  with	  both	  large-­‐scale	  and	  small-­‐scale	  fleets	   in	   the	  hope	  of	  giving	  a	  more	  holistic	  picture	  of	   the	   impacts	  of	   commercial	   tuna	  fishing	  in	  the	  Pacific	  Ocean.	  	   Lastly,	  to	  observe	  the	  further	  importance	  of	  obtaining	  adequate	  catch	  data,	  and	  its	  application	  beyond	  catch	  reconstructions,	  a	  review	  of	  the	  accuracy	  of	  the	  Catch-­‐MSY	  9	  method	  developed	  by	  Martell	  and	  Froese	  (2012)	  will	  be	  applied	  in	  the	  context	  of	  Pacific	  Ocean	  tuna	  stocks.	  	  	   10	  	  	  	  	  2 |	  THE	  DEMISE	  OF	  DARWIN’S	  FISHES4	  	  	  "But	  what	  does	  that	  mean—	  ‘ephemeral’?”	  repeated	  the	  little	  prince,	  who	  never	  in	  his	  life	  had	  let	  go	  of	  a	  question,	  once	  he	  had	  asked	  it.	  “It	  means,	  'which	  is	  in	  danger	  of	  a	  speedy	  disappearance.'"	  	  -­‐Antoine	  de	  Saint-­‐Exupéry,	  The	  Little	  Prince	  	  	  	   	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  4A	  version	  of	  this	  chapter	  has	  been	  published:	  Schiller	  L,	  Alava	  JJ,	  Grove	  J,	  Reck	  G,	  and	  Pauly	  D.	  2014.	  The	  Demise	  of	  Darwin’s	  Fishes:	  Evidence	  of	  fishing	  down	  and	  illegal	  shark	  finning	  in	  the	  Galápagos	  Islands.	  Aquatic	  Conservation:	  Marine	  and	  Freshwater	  Ecosystems.	  doi:	  10.1002/aqc.2458. 11	  INTRODUCTION	  Island	  geography	  and	  demographics	  Located	   1,000	   km	  west	   of	  mainland	   Ecuador	   in	   the	   eastern	   Pacific	  Ocean,	   the	  Galápagos	   Islands	   (1°40'N–1°36'S,	   89°16'–92°01'W)	   have	   been	   a	   subject	   of	   curiosity,	  mystery,	  and	  scientific	  discovery	  for	  nearly	  five	  hundred	  years.	  Charles	  Darwin’s	  voyage	  aboard	  the	  H.M.S.	  Beagle	   in	  1835	   (Pauly	  2004)	  offered	  him	  the	  unique	  opportunity	   to	  take	  a	  variety	  of	  biological	  specimens	  from	  this	  region.	  And,	  although	  best	  known	  for	  his	  descriptions	  of	   finches,	  Pauly	   (2004)	  demonstrates	   that	  Darwin’s	   subsequent	   research	  on	   speciation	   was	   actually	   largely	   influenced	   by	   the	   phenotypic	   variations	   that	   he	  observed	  in	  fish	  species,	  rather	  than	  in	  birds.	  At	  present,	   the	  Galápagos	  archipelago	  encompasses	  thirteen	   islands	   (>	  10	  km2;	  Table	   2-­‐1)	   and	   over	   100	   islets	   (Snell	   et	   al.	   1996).	   Although	   frequented	   by	   sailors	   and	  explorers	  since	  their	  initial	  discovery,	  permanent	  human	  residency	  in	  the	  Galápagos	  only	  began	   in	   the	  1830s	   (Camhi	  1995).	  The	  population	  remained	  quite	   low	  until	   the	  1970s,	  when	   political	   and	   social	   issues	   in	   Ecuador,	   combined	   with	   increased	   tourism	   to	   the	  Islands,	  contributed	  to	  substantial	  emigration	  from	  the	  mainland	  (Epler	  2007).	  Realizing	  the	  need	   to	  preserve	   the	  unique	  environment	  of	   the	   archipelago,	   the	  Government	  of	  Ecuador	  proactively	  designated	  the	  Galápagos	  as	  a	  national	  park	  in	  1959;	  in	  1979,	  it	  was	  further	   declared	   a	   UNESCO	   World	   Heritage	   Site	   (Camhi	   1995;	   Bensted-­‐Smith	   et	   al.	  2002).	   In	   1998,	   the	   foundation	   of	   the	   Galápagos	   Marine	   Reserve	   (GMR)	   endowed	   a	  protective	  boundary	  around	  the	  archipelago,	  which	  extends	  60	  km	  beyond	  the	   islands	  and	  encompasses	  138,000	  km2	  (Camhi	  1995;	  Heylings	  and	  Bensted-­‐Smith	  2002),	  making	  	   12	  it	  one	  of	  the	  largest	  marine	  protected	  areas	  in	  the	  world.	  	   With	  five	  inhabited	  islands,	  the	  2010	  population	  of	  the	  Galápagos	  was	  estimated	  at	  over	  25,000—a	  dramatic	  increase	  from	  the	  approximately	  2,000	  individuals	  who	  lived	  there	   in	  1959	   (Bremner	  and	  Perez	  2002;	   INEC	  2011).	  Unfortunately,	  as	  a	   result	  of	   this	  colonization,	  the	  Galápagos	  suffers	  from	  many	  of	  the	  same	  problems	  that	  have	  affected	  geographically	   isolated	   regions	   throughout	  history:	   species	   invasions	   (1,321	   spp.	   as	  of	  2007),	  increasing	  	  human	  	  population	  	  	  growth,	  	  	  and	  	  	  the	  	  	  use	  	  	  of	  	  	  natural	  	  	  habitat	  	  	  for	  Table	  2-­‐1.	  Geography	  and	  fishing	  demographics	  of	  the	  Galápagos	  Islands.	  	   13	  agriculture	   (Causton	   et	   al.	   2006;	   Watkins	   and	   Cruz	   2007;	   Mauchamp	   and	   Atkinson	  2010).	  	   Additionally,	   the	  ecotourism	  industry	  of	  this	  archipelago	  has	  exploded	  over	  the	  latter	  half	  of	  the	  20th	  century.	  Until	  the	  mid-­‐1970s,	  tourism	  in	  the	  Galápagos	  Islands	  was	  virtually	   non-­‐existent.	   Approximately	   two-­‐thousand	   people	   visited	   the	   archipelago	   in	  1969	  (Epler	  2007).	  This	  is	  a	  tiny	  fraction	  of	  the	  180,831	  people	  who	  visited	  them	  in	  2012	  (PNG	   2013),	   and	   whose	   activities	   result	   in	   a	   direct,	   local,	   annual	   profit	   of	   over	   $60	  million	   (Watkins	   and	   Cruz	   2007).	   This	   exponential	   gain	   in	   foreign	   attention	   and	   the	  negative	   impact	   it	   is	   having	   on	   the	   Islands’	   environment	   remains	   one	   of	   the	   primary	  threats	  facing	  the	  Galápagos	  today.	  	  Overview	  of	  Galápagos	  fisheries	  	   The	   biodiversity	   of	   the	   Galápagos	   Islands	   is	   extensive:	   they	   are	   home	   to	   a	  cornucopia	   of	   species,	   and	   nearly	   20%	   of	   the	   sea	   life	   is	   endemic	   (Bustamante	   et	   al.	  2002).	  One	  of	  the	  most	  unique	  characteristics	  of	  these	  islands	  is	  the	  unconventional	  co-­‐existence	  of	  tropical,	  temperate,	  and	  Southern	  Ocean	  species	  within	  such	  a	  small	  region	  (Jackson	  2001).	  Such	  assemblages	  are	  made	  possible	  by	  deep	  near-­‐shore	  waters,	  strong	  currents,	  and	  nutrient-­‐rich	  upwellings,	  which	  provide	  an	  excellent	  habitat	  for	  over	  2,900	  fish,	   aquatic	   invertebrates,	   and	   marine	   mammals	   (Grove	   and	   Lavenberg	   1997;	  Bustamante	   et	   al.	   2002;	   Okey	   et	   al.	   2004;	   Castrejón	   2011).	   Human	   exploitation	   of	  marine	   life	   at	   a	   large	   scale	   in	   the	  Galápagos	   began	   in	   the	   late	   18th	   century,	  with	   the	  onset	   of	   hunting	   of	  Galápagos	   fur	   seals	   (Arctocephalus	   galapagoensis)	   for	   their	   pelts,	  and	   with	   commercial	   whaling,	   the	   latter	   subsequently	   leading	   to	   the	   rapid	   local	  	   14	  depletion	  of	  sperm	  whales	  (Physeter	  macrocephalus)	  (Townsend	  1934;	  Whitehead	  et	  al.	  1997;	   Toral-­‐Granda	   et	   al.	   2000).	   Although	   these	   industries	   lasted	   less	   than	   a	   few	  decades	   each,	   fishers	   have	   exploited	   the	   rich	   marine	   ecosystem	   surrounding	   the	  Galápagos	  ever	   since	  and,	  presently,	   the	  economic	   importance	  of	   the	   fishing	   sector	   is	  second	  only	  to	  tourism	  (Bremner	  and	  Perez	  2002).	  	  	   Fishing	   activity	   within	   the	   GMR	   is	   currently	   organized	   by	   zones,	   whereby	  subsistence	   and	   artisanal	   fishing	   is	   allowed	   in	   specified	   locations	   and	   all	   large-­‐scale	  industrial	   fishing	   has	   been	   prohibited	   since	   1998	   (Jennings	   et	   al.	   1994;	   Jacquet	   et	   al.	  2008).	   The	   main	   fishing	   ports	   in	   the	   Galápagos	   are	   located	   on	   San	   Cristóbal	   (Puerto	  Baquerizo	  Moreno),	   Isabela	   (Puerto	  Villamil)	  and	  Santa	  Cruz	   (Puerto	  Ayora)	   (Castrejón	  2011);	   these	   towns	   service	   the	   three	   primary	   artisanal	   fisheries	   in	   the	   archipelago:	  finfish5 	  (year	   round),	   sea	   cucumber	   (seasons	   from	   March/April	   to	   May/June),	   and	  lobster	  (July/September	  to	  December/February)	  (Bustamante	  1999;	  Jácome	  and	  Ospina	  1999;	  Toral-­‐Granda	  et	  al.	  2000).	  The	  artisanal	  fleet	  of	  the	  Galápagos	  is	  largely	  made	  up	  of	  small	  fishing	  boats	  with	  limited	  technology.	  Based	  on	  size,	  the	  vessels	  are	  divided	  into	  three	  main	  types:	  botes	   (wooden	  boats,	  7-­‐16	  m	  with	  diesel	  engines),	  pangas	   (plywood	  boats,	  3-­‐6	  m	  with	  60Hp	  outboard	  motor)	  and	  fibras	  (fiberglass	  boats,	  5-­‐9m	  with	  >60Hp	  large	  outboard	  motor)	  (Bustamante	  1998).	  	  	   Between	  1971	  and	  2000,	  the	  number	  of	  fishers	  increased	  by	  326%	  from	  160	  to	  682	   individuals	   (Bustamante	   1998;	   Toral-­‐Granda	   et	   al.	   2000).	   This	   substantial	  intensification	  in	  fishing	  effort	  and	  vessels	  (mainly	  pangas)	  was	  largely	  influenced	  by	  the	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  5Commonly	  referred	  to	  as	  ‘whitefish’	  in	  the	  Galapagos,	  this	  term	  refers	  to	  all	  teleost	  species	  landed	  by	  the	  artisanal	  fleet,	  regardless	  of	  the	  colour	  of	  their	  flesh.	  	   15	  economical	   incentives	   generated	   by	   the	   lucrative	   sea	   cucumber	   fishery	   in	   the	   1990s.	  Conversely,	   from	  2000-­‐2007,	   there	  was	   a	   65%	  decrease	   in	   the	   total	   number	  of	   active	  fishers	   in	  the	  Galápagos,	   likely	  due	  to	  the	  diminishing	  profitability	  of	   the	  major	  export	  fisheries	   (spiny	   lobster	   and	   sea	   cucumber),	   and	   subsequent	   shifts	   in	   livelihood	  (Castrejón	  2011).	  	  	  Artisanal	  fisheries	  From	   1998,	   artisanal	   fisheries	   were	   regulated	   through	   a	   co-­‐management	  approach	   and	   internal	   consensus	   process	   led	   by	   the	   Galápagos	   Marine	   Reserve’s	  Participatory	   Management	   System	   Board	   (PMS),	   which	   encompassed	   several	  stakeholder	   groups	   (Artisanal	   Fishers	   Association,	   Charles	   Darwin	   Research	   Station,	  Tourism	  Galápagos	  Chamber	  and	  Galápagos	  National	  Park	  Service)	  and	  was	  approved	  by	  the	  Inter–institutional	  Management	  Authority	  (IMA)6.	  The	  PMS	  was	  legally	  founded	  on	  three	   fundamental	   principles:	   participation,	   precaution,	   and	   adaptive	   management,	  with	   the	   overall	   aim	   of	   creating	   a	   consensus	   building	   process	   that	   allowed	   local	  stakeholders	   (i.e.,	   fishers,	   natural	   guides,	   tourism	   operators,	   and	   conservationist-­‐environmentalist	   groups)	   to	   participate	   in	   decision	  making	   for	   the	   sustainable	   use	   of	  marine	   resources	   (Castrejón	   et	   al.	   2005;	   Castrejón	   2011).	   Therefore,	   artisanal	   fishing	  was	   conducted	   in	   agreement	  with	  negotiations	  and	   regulations	  enacted	  by	   the	  GNPS.	  The	  legal	  framework	  for	  fishing	  was	  thus	  focused	  on	  permits,	  including	  seasonal	  fishing	  openings,	  quotas,	  and	  limits	  on	  the	  number	  of	  active	  fishers.	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  6The	  IMA	  is	  the	  government	  entity	  conformed	  by	  the	  Ministries	  of	  Fishery,	  Tourism,	  Environment	  and	  Defense	  and	  is	  based	  in	  continental	  Ecuador.	  16	  However,	   declines	   in	   the	   abundance	   of	   both	   sea	   cucumber	   and	   spiny	   lobster,	  and	   diminishing	   economic	   rent	   resulted	   in	   the	   realization	   that	   the	   initial	   co-­‐management	  model	   coupled	  with	   legal	   tools	   for	   sustainable	   fisheries	  management	   in	  the	   GMR	   had	   not	   accomplished	   its	   original	   goals	   (Castrejón	   2011).	   As	   such,	   the	  Participatory	  Fisheries	  Stock	  Assessment	   (ParFish)	  model	  was	  developed	  to	  assess	  and	  improve	   the	  co-­‐management	   system	  by	   taking	   into	  account	   the	   local	   idiosyncrasies	  of	  the	  Galápagos	  and	  the	  legal	  framework	  of	  fisheries	  management.	   	  The	  ParFish	  process	  ran	   from	   February	   2006	   to	   January	   2009,	   and	   the	   activities	   and	   results	   obtained	   are	  described	  in	  Castrejón	  (2011).	  The	  outcomes	  of	  this	  exercise	  were	  used	  as	  inputs	  by	  the	  PMS	  to	  formulate	  a	  new	  proposal	  for	  the	  GMR	  fishery	  management	  (“Capítulo	  Pesca”),	  which	  was	  approved	  by	  the	  IMA	  in	  20097.	  	  i. Bacalao	  and	  finfishThe	  Galápagos	  finfish	  fishery	  has	  a	  long	  history	  in	  the	  Islands	  and	  dates	  back	  tothe	  time	  of	  colonization,	  when	  about	  a	  dozen	  species	  of	  fish	  were	  taken	  for	  subsistence	  (Reck	  1983;	  Toral-­‐Granda	   et	  al.	   2000;	  Castrejón	  2011).	  Today,	   fish	  have	   four	  potential	  destinations:	   i)	   local	  markets	  where	   they	  are	   sold	   fresh	   to	  Galápagos	   residents;	   ii)	   the	  tourism	   sector	   (e.g.,	   hotels,	   dive	   boats)	   for	   consumption	   by	   tourists;	   iii)	   dried	   and	  exported	   to	   mainland	   Ecuador	   for	   local	   consumption;	   or	   iv)	   freshly	   exported	   to	   the	  mainland	  for	  further	  export	  to	  the	  United	  States	  (Nicolaides	  et	  al.	  2002).	  As	  detailed	  in	  Reck	  (1983),	  commercial	   finfish	  fishing	  became	  permanently	  established	   in	  1945,	  after	  7 From:	   http://www.galapagospark.org/documentos/capitulo_pesca_reserva_marina_galapagos.pdf	  [accessed	  12	  December	  2012].	  17	  failed	  attempts	  in	  the	  1920s	  and	  1930s.	  For	  decades,	  the	  primary	  target	  of	  this	  hand-­‐line	  fishery	  was	  the	  Galápagos	  grouper	  (Mycteroperca	  olfax),	  a	  species	  locally	  referred	  to	  as	  bacalao8	  (Reck	  1983;	  Nicolaides	   et	   al.	   2002).	   In	   the	  past,	   this	   species	  was	   fished	   from	  October	  to	  March,	  dried,	  and	  exported	  to	  mainland	  Ecuador	  for	  use	  in	  traditional	  Easter	  soup	  (Nicolaides	  et	  al.	  2002).	  There	  has	  since	  been	  a	  decline	  in	  the	  abundance	  of	  M.	  olfax	   (Ruttenberg	  2001;	  Banks	  2008),	  and	  64%	  of	  fishers	  from	  Puerto	  Baquerizo	  Moreno	  (traditionally	  the	  main	  fishing	  port	   for	  the	  catch	  and	  export	  of	  bacalao)	  have	  observed	  declines	   in	  their	  catch	  rates	  (Castrejón	  2011).	  However,	  Galápagos-­‐wide	  catch	  rates	  appear	  to	  have	  remained	  stable	  since	  the	  1970s.	  These	  two	  seemingly	  contradictory	  observations	  suggest	  that	  the	  fishery	  is	  expanding	  throughout	  the	  Islands.	  Castrejón	  (2011)	  additionally	  suggests	  that	  within	   the	   finfish	   fishery	   there	   exist	   cases	   of	   ‘shifting	   baselines	   syndrome’,	   whereby	  newer	  generations	  of	  fishers	  do	  not	  perceive	  declines	  in	  abundance	  to	  be	  as	  dramatic	  as	  they	  are	  in	  reality,	  since	  the	  state	  of	  the	  environment	  for	  their	  initial	  frame	  of	  reference	  (i.e.,	  when	  they	  started	  fishing)	   is	  already	  vastly	  different	   from	  the	  pristine,	  pre-­‐fished	  state	  (Pauly	  1995).	  	  	  ii. Sea	  cucumberInitially	   established	   in	   1991	   after	   mainland	   Ecuadorian	   sea	   cucumber	   stockscollapsed,	   the	   artisanal	   sea	   cucumber	   fishery	   has	   a	   relatively	   short,	   but	   problematic,	  history	  in	  the	  Galápagos	  (Shepherd	  et	  al.	  2004;	  Castrejón	  et	  al.	  2005;	  Hearn	  et	  al.	  2005;	  8The	   English	   translation	   of	   bacalao	   is	   ‘cod’	   (Family	   Gadidae);	   however	   M.	   olfax	   is	   a	   grouper	   (i.e.,	   a	  member	  of	  the	  family	  Serranidae).	  	  	   18	  Toral-­‐Granda	  2008).	  The	  primary	  fishing	  grounds	  are	  located	  on	  the	  west	  side	  of	  Isabela	  Island,	   near	   the	   Bolivar	   Channel	   (Castrejón	   2011).	   While	   nearly	   forty	   species	   of	   sea	  cucumber	   occur	  within	   the	   archipelago	   (Maluf	   1991,	   in	   Toral-­‐Granda	   2008),	   it	   is	   only	  legal	  to	  harvest	  the	  brown	  sea	  cucumber	  (Isostichopus	  fuscus);	  illegal	  fishing	  operations	  exist	  for	  at	  least	  three	  other	  species	  (Toral-­‐Granda	  2008).	  	   	  	   Although	   there	  were	   initial	   efforts	   to	   ensure	   the	   sustainable	   extraction	   of	   this	  resource,	   overfishing	   and	   illegal	   catches	   strongly	   contributed	   to	   the	   closure	   of	   the	  fishery	   in	  1992	   (Bremner	  and	  Perez	  2002).	  However,	   this	  moratorium	   lasted	  only	   two	  years	  before	  the	  fishery	  was	  again	  opened	  for	  a	  brief	  three-­‐month	  trial	  period.	  The	  total	  allowable	  catch	  (TAC)	  set	  for	  the	  trial	  period	  was	  500,000	  sea	  cucumbers,	  but	  a	  lack	  of	  enforcement	   and	   management	   resulted	   in	   an	   actual	   take	   of	   between	   6-­‐10	   million	  individuals	  before	  the	  fishery	  was	  again	  closed	  (Camhi	  1995).	  The	  sea	  cucumber	  fishers	  (pepineros)	   did	  not	   take	   the	   closure	   lightly,	   and	   violently	  protested	   to	   the	  Ecuadorian	  Government	  by	  seizing	  Galápagos	  National	  Park	  Service	  offices	  and	  the	  Charles	  Darwin	  Foundation	  (CDF),	  and	  by	  threatening	  Galápagos	  tortoises	  (Geochelone	  spp.),	  an	  action	  that	  has	  occurred	  on	  more	  than	  one	  occasion	  (Camhi	  1995;	  Stone	  1995;	  Ferber	  2000).	  Despite	  these	  demonstrations,	  the	  fishery	  remained	  closed	  until	  1999.	  	  	   Recent	   management	   efforts,	   including	   the	   implementation	   of	   an	   individual	  transferable	   quota	   (ITQ)	   system	  and	  minimum	   size	   restrictions	   suggest	   that	   there	   are	  ongoing	   attempts	   to	   manage	   the	   sea	   cucumber	   fishery	   more	   effectively.	   However,	  population	  sizes	  are	  still	  variable	  and	  recovery	  appears	  to	  be	  slow	  (Toral-­‐Granda	  2008;	  Castrejón	  2011).	  Additional	  conservation	  precaution	  was	  made	  in	  2003,	  when	   I.	   fuscus	  19	  became	  the	   first	   sea	  cucumber	  species	   listed	  under	  Appendix	   III	  of	   the	  Convention	  on	  International	   Trade	   in	   Endangered	   Species	   of	   Wild	   Fauna	   and	   Flora	   (CITES)	   (Toral-­‐Granda	  2008).	  However,	  the	  following	  year,	  383,000	  sea	  cucumbers	  (approximately	  100	  t) were	  caught	  without	  a	  CITES	  permit	   (Toral-­‐Granda	  2008).	  Additionally,	  although	  theCDF	  estimated	  a	  maximum	  sustainable	  quota	  of	  450,000	  sea	  cucumbers	   for	  2004,	   the	  IMA	  allowed	  an	  opening	  season	  for	   two	  months	  with	  a	  maximum	  capture	  of	  3	  million	  individuals,	  and	  a	  total	  moratorium	  for	  2005	  and	  2006.	  However,	  the	  last	  resolution	  was	  revoked,	   leading	  to	  a	  judicial	  trial	  and	  claims	  for	  an	  extension	  of	  the	  fishing	  season,	  as	  well	  as	  to	  permit	  fishing	  of	  sea	  cucumbers	  in	  no-­‐take	  areas,	  where	  fisheries	  or	  extractive	  activities	   are	   excluded	   (i.e.,	   Fernandina	   Island	   and	   Bolivar	   Channel).	   Ultimately,	   the	  fishery	  was	  open	   for	   2005,	   but	   closed	   in	   2006	   in	   an	  effort	   to	   allow	   the	  population	   to	  recover.	  Due	  to	  increased	  concerns	  over	  population	  health,	  it	  was	  again	  closed	  between	  2009-­‐2010.	  	  iii. Spiny	  and	  slipper	  lobsterThe	   red	   spiny	   lobster	   (Panulirus	   penicillatus)	   and	   the	   green	   (or	   blue)	   spinylobster	   (Panulirus	   gracilis)	   have	   been	   fished	   for	   commercial	   export	   since	   the	   1960s	  (Bustamante	  et	  al.	  2000),	  and	  previous	  estimates	  suggest	  that	  the	  Galápagos	  has	  always	  contributed	   upward	   of	   90-­‐95%	   to	   Ecuador’s	   total	   spiny	   lobster	   export	   (Reck	   1983;	  Bustamante	  et	  al.	  2000).	  Between	  1979	  and	  1980,	  the	  average	  CPUE	  for	  spiny	  lobsters	  was	  10.7	  kg	  of	   tails	   ⋅	  diver-­‐1	  ⋅	  day-­‐1	   (peaking	  at	  12.4	  kg	  of	   tails	   ⋅	  diver-­‐1	  ⋅	  day-­‐1	   in	  1978).	  However,	  from	  1994-­‐2006,	  the	  average	  CPUE	  was	  only	  6.6	  kg	  of	  tails	  ⋅	  diver-­‐1	  ⋅	  day,	  and	  an	  all-­‐time	  low	  of	  4.0	  kg	  of	  tails	  ⋅	  diver-­‐1	  ⋅	  day-­‐1	  was	  observed	  in	  2005	  (Hearn	  et	  al.	  2006,	  	   20	  in	  Castrejón	  2011).	  Given	  these	  changes	  in	  catch	  rate,	  the	  spiny	  lobster	  fishery	  incurred	  a	   brief	   18-­‐month	   closure	   in	   1994.	   Although	   declines	   in	   abundance	   have	   caused	   the	  commercial	   value	   of	   these	   species	   to	   increase	   (US	   $28.60⋅	   kg-­‐1	   in	   2006	   compared	   to	  US$7.92	   in	   1997),	   there	   has	   been	   a	   substantial	   decrease	   in	   the	   gross	   income	   of	   the	  fishery	  (Hearn	  et	  al.	  2006).	  In	  addition	  to	  the	  spiny	  lobsters,	  a	  similar	  species,	  the	  slipper	  lobster	   (Scyllarides	  astori),	   is	  also	  harvested	  at	  a	   smaller	   scale	   (Hearn	  2006).	  Although	  endemic	   to	   the	   Eastern	   Pacific,	   the	   slipper	   lobster	   is	   not	   as	   valuable	   as	   the	   spiny	  lobsters;	  thus	  it	  is	  sold	  primarily	  for	  local	  consumption	  (Bustamante	  et	  al.	  2000).	  	  Industrial	  fishery	  for	  tuna	  	   Records	   allude	   to	   industrial	   fleets	   in	   Galápagos	  waters	   catching	   approximately	  400	  t	  of	  tuna	  as	  far	  back	  as	  1933,	  and	  2,300	  t	  in	  1940	  (CDF	  2010).	  Fishing	  pressure	  from	  both	   foreign	   fleets	   and	   mainland-­‐based	   Ecuadorian	   vessels	   has	   increased	   ever	   since	  (Shimada	   1958;	   Castro	   2005;	   Bedoya	   2009),	   and	   the	   primarily	   targeted	   species	   in	   the	  Eastern	   Pacific	   Ocean	   (EPO)	   are	   skipjack	   (Katsuwonus	   pelamis),	   bigeye	   (Thunnus	  obesus),	   and	   yellowfin	   (Thunnus	   albacares).	   At	   present,	   Ecuador’s	   EPO	   tuna	   fleet	  consists	   of	   86	   vessels	   (IATTC	   2011a),	   although	   only	   a	   small	   fraction	   of	   these	   operate	  within	   the	  Galápagos	  EEZ.	  Since	   the	  GMR	  prohibits	   large-­‐scale	   industrial	   fishing	  within	  its	  borders,	   this	   type	  of	   tuna	   fishing	   is	   limited	   to	   regions	   farther	  offshore.	  However,	   it	  has	  been	  observed	  that	  foreign	  vessels	  operating	  under	  fishing	  access	  agreements	  with	  Ecuador	  do	  not	   respect	   the	   rules	  or	   the	   integrity	  of	   the	  GMR	  (Bustamante	  1999),	  and	  incidents	  of	  illegal	  fishing	  within	  the	  marine	  reserve	  are	  an	  ongoing	  concern	  (Altamirano	  and	  Aguiñaga	  2002;	  Reyes	  and	  Murillo	  2007).	   Independent	  of	  the	   industrial	  endeavors	  21	  of	  Ecuador’s	  fleet,	  artisanal	  tuna	  fishing	  by	  local	  Galápagos	  fishers	  is	  allowed	  within	  the	  GMR	  and	  these	  catches	  are	  considered	  as	  part	  of	  the	  finfish	  fishery.	  Shark	  fishing	  In	  addition	  to	  the	  plethora	  of	  teleost	  fishes	  in	  the	  Galápagos	  Islands,	  a	  significant	  diversity	   of	   sharks	   has	   also	   been	   recorded	   in	   this	   region	   (Grove	   and	   Lavenberg	   1997;	  Zarate	   2002;	   Carr	   et	   al.	   2013).	   Among	   these	   species,	   it	   is	   possible	   to	   find	   schools	   of	  hammerhead	   (scalloped,	   Sphyrna	   lewini	   and	   smooth,	   S.	   zygaena),	   tiger	   (Galeocerdo	  cuvierii),	   mako	   (Ixurus	   oxyrhinchus),	   white-­‐tipped	   reef	   (Triaenodon	   obesus),	   blue	  (Prionace	   glauca),	   Galápagos	   (Carcharhinus	   galapagoensis),	   oceanic	   whitetip	  (Carcharhinus	   longimanus),	   silky	   (Carcharhinus	   falciformis),	   three	   species	   of	   thresher	  (Alopias	  vulpinus;	  A.	  superciliosus;	  and	  A.	  pelagicus),	  and	  even	  whale	  sharks	  (Rhincodon	  typus).	   About	   90%	   of	   the	   elasmobranchs	   found	   around	   the	   Galápagos	   have	   been	  included	  on	  the	   IUCN	  Red	  List	  as	   ‘Threatened’	  or	   ‘Near-­‐Threatened’	   (Carr	  et	  al.	  2013).	  The	   scalloped	   hammerhead,	   one	   of	   the	   most	   abundant	   and	   gregarious	   sharks	   in	  Galápagos	  marine	  waters	  (Stone	  1995;	  Coello	  1996),	  was	  recently	  moved	  up	  from	  ‘Near	  Threatened’	   to	   ‘Endangered’	   status,	   and	   both	   the	   whale	   and	   great	   white	   sharks	   are	  categorized	  as	  ‘Vulnerable’9.	  Shark	  fishing	  and	  finning	  has	  been	  conducted	   in	  the	  Galápagos	  since	  the	  1950s	  (Watts	   and	   Wu	   2005;	   Jacquet	   et	   al.	   2008).	   Sharks	   caught	   in	   Galápagos	   waters	   are	  typically	   landed	   on	   the	   Ecuadorian	   mainland;	   the	   destination	   and	   connection	   ports	  where	  illegal	  operations	  take	  place	  are	  Guayaquil	  and	  Manta,	  the	  two	  major	   industrial	  9From:	  http://www.iucnredlist.org	  [accessed	  9	  August	  2012]	  	   22	  and	   harbor	   fishery	   cities.	   	   Fishing	   for	   sharks	   in	   the	   Galápagos	   became	   increasingly	  prevalent	   in	   the	   1980s	   and	   the	  magnitude	   of	   this	   endeavor	   has	   increased	   ever	   since	  (Camhi	  1995;	  Coello	  1996;	  Watts	  and	  Wu	  2005).	  Between	  1988	  and	  1991,	   illegal	  shark	  fisheries	  were	  discovered	  to	  be	  using	  pieces	  of	  sea	   lion	   flesh	  as	  bait,	  and	  the	  onset	  of	  finning	   practices	   with	   the	   discard	   of	   shark	   bodies	   led	   to	   the	   slaughter	   of	   tens	   of	  thousands	  of	  sharks	  for	  the	  Asian	  market	  (Camhi	  1995;	  Merlen	  1995).	  	  These	  operations	  were	  conducted	   largely	  by	  Ecuadorian,	  Colombian,	  Costa	  Rican,	   Japanese,	  Taiwan	  and	  Korea	  semi-­‐industrial	  and	  industrial	  longline	  fishing	  fleets,	  some	  of	  which	  were	  licensed	  only	  for	  tuna	  fishing,	  but	  were	  illegally	  fishing	  for	  sharks	  (Camhi	  1995;	  Merlen	  1995).	  Sportfishing	  The	  traditional	  ‘trophy	  hunting’	  approach	  to	  sport	  fishing	  began	  in	  the	  Galápagos	  in	  the	  1990s.	  However,	   these	  activities	  were	  highly	  unregulated	  and	  operated	  without	  the	  consent	  of	  local	  fishers	  (Schuhbauer	  and	  Koch	  2013).	  As	  such,	  this	  type	  of	  tourism	  is	  not	  currently	  supported	  by	  the	  GMR	  and	  is	  prohibited	  within	  its	  boundaries	  (PNG	  2009).	  Since	  2005,	  recreational	  sport	  fishing	  by	  tourists	  in	  the	  Galápagos	  has	  been	  based	  on	  the	  Pesca	   Artesanal	   Vivencial	   (PVA)	   approach	   instead	   (Schuhbauer	   and	   Koch	   2013).	   This	  new,	   experimental	   initiative	   aims	   at	   giving	   local	   fishers	   an	   alternative	   to	   commercial	  fishing,	   and	   tourists	   the	   chance	   to	   spend	   a	   day	   with	   a	   local	   licensed	   fisher.	   Fish	   are	  meant	  to	  be	  caught	  using	  traditional	  gear	  and	  methods	  and,	  with	  the	  exception	  of	  spiny	  lobsters	   caught	   during	   the	   harvest	   season,	   all	   catch	   is	   legally	   required	   to	   be	   released	  (PNG	  2009).	  Although	  very	  little	  assessment	  of	  PVA	  has	  been	  conducted,	  initial	  research	  suggests	  that	  this	  program	  has	  not	  been	  successful	  (largely	  due	  to	  a	  lack	  of	  organization	  	   23	  and	   clearly	   defined	   regulations),	   and	   despite	   efforts	   to	   avoid	   traditional	   sport	   fishing,	  these	  activities	  remain	  prevalent	  within	  the	  archipelago	  (Schuhbauer	  and	  Koch	  2013).	  	  METHODS	  	   Given	  the	  lack	  of	  catch	  reporting	  by	  Galápagos	  fishers,	  it	  is	  unknown	  how	  much	  (if	   any)	   data	   from	   the	   fisheries	   of	   the	   Galápagos	   are	   pooled	   with	   the	   FAO	   data	   for	  Ecuador	   as	   a	   whole.	   The	   finfish	   species	   associated	   with	   the	   Galápagos	   (e.g.	   bacalao,	  mullet)	   were	   not	   featured	   independently	   in	   Ecuador’s	   data	   set	   and	   it	   was	   therefore	  assumed	  they	  were	  not	  included.	  Conversely,	  the	  start	  of	  Ecuador’s	  recorded	  catch	  data	  of	   other	   species,	   including	   spiny	   lobsters	   and	   sea	   cucumbers,	   did	   appear	   to	   be	  correlated	  with	  the	  commencement	  of	  these	  fisheries	  in	  the	  Galápagos.	  Therefore,	  in	  an	  effort	   to	   avoid	   overestimating	   or	   double	   counting,	   it	   was	   assumed	   that	   for	   these	  fisheries,	  Galápagos	  catches	  were	  included	  within	  the	  FAO	  Ecuador	  data.	  	  Local	  consumption	  	   In	   order	   to	   calculate	   the	   amount	   of	   fish	   consumed	   at	   a	   local	   level,	   GraphClick	  was	  used	  to	  extract	  permanent	  residency	  data	  from	  Taylor	  et	  al.	  (2010),	  and	  Galápagos	  National	  Park	  entry	  records	  were	  used	  to	  estimate	  the	  amount	  of	  tourism	  from	  1979	  to	  present10.	   Additional	   information	   was	   also	   obtained	   from	   González	   et	   al.	   (2000)	   and	  Ecuador’s	   Instituto	  Nacional	  de	  Estadística	  y	  Censos	   (INEC)11,	   and	   linear	   interpolations	  were	  performed	   to	   “fill	   in”	  data	   gaps.	  Although	  an	  archipelago-­‐wide	   value	  of	   seafood	  consumption	   could	  not	  be	   found,	   as	  determined	   in	   a	   study	  on	   consumption	  on	   Santa	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  10From:	  http://www.galapagospark.org/onecol.php?page=turismo_estadisticas	  [accessed	  2	  May	  2012].	  11From:	  http://www.inec.gob.ec/cpv/	  [accessed	  4	  May	  2012]. 24	  Cruz	  Island,	  6.75	  kg	  person-­‐1	  ⋅	  year-­‐1	  was	  used	  as	  the	  2010	  per	  capita	  consumption	  rate	  for	   locals,	  and	  1.1	  kg	  person-­‐1	   ⋅	  vacation-­‐1	  was	  used	   for	   tourists	   (Manuba	  2007).	  Given	  decreased	  accessibility	   to	   food	   from	   the	  mainland,	   it	  was	  assumed	   that	   locally	   caught	  seafood	  was	  more	  prominent	  in	  people’s	  diets	  on	  the	  Islands	  for	  the	  earlier	  time	  period.	  Thus,	   a	   starting	   per	   capita	   consumption	   1.5	   times	   higher	   than	   present	   (i.e.,	   10.1	   kg	  person-­‐1	  ⋅	  year-­‐1	  for	  locals	  and	  1.4	  kg	  person-­‐1	  ⋅	  vacation-­‐1	  for	  tourists)	  was	  used	  for	  1950.	  Linear	  interpolation	  between	  past	  and	  present	  per	  capita	  consumption	  rates	  applied	  to	  the	   population	   over	   time	   was	   therefore	   used	   to	   determine	   a	   subsistence	   catch	  component.	  	  Bacalao	  and	  finfish	  Early	   anecdotal	   estimates	   by	   Reck	   (1983)	   suggest	   annual	   finfish	   landings	   of	  approximately	  500	  t	  in	  the	  1950s.	  However,	  this	  observation	  is	  difficult	  to	  contextualize,	  as	  no	  other	  catch	  statistics	  for	  this	  time	  exist.	  Nonetheless,	  this	  tonnage	  was	  used	  as	  the	  starting	  point	  for	  1950	  and	  held	  constant	  until	  1955.	  No	  data	  were	  available	  until	  1977	  (Reck	  1983),	  so	  linear	  interpolation	  was	  used	  between	  these	  years.	  GraphClick	  was	  used	  to	   extract	   data	   from	   a	   time	   series	   of	   catches	   in	   Castrejón	   (2011)	   and	   additional	   time	  series	   (Andrade	   and	   Murillo	   2002;	   Anonymous	   2009)	   served	   as	   anchors	   for	   further	  interpolations.	   Export	   data	   provided	   by	   CDF	   were	   again	   used	   to	   calculate	   the	   catch	  between	  2004-­‐2010.	  Up	  until	  the	  1970s,	  mullets	  were	  not	  considered	  part	  of	  the	  finfish	  catch	   (Reck	   1983);	   since	   later	   data	   sets	   did	   include	   them	   with	   as	   part	   of	   the	   finfish	  fishery,	   the	   calculated	   catches	   of	   Mugil	   galapagensis	   and	   Xenomogil	   thornburi	   were	  added	  to	  the	  earlier	  finfish	  catch	  data.	  	   25	  	   Approximate	   species	   breakdowns	   were	   available	   from	   the	   aforementioned	  sources;	  when	   these	  were	   unavailable,	   the	   species	   composition	   for	   known	   years	  was	  calculated	  and	  applied	   it	   to	  the	  total	  catch.	  Specifically,	   the	  catch	  composition	  of	  Reck	  (1983)	   was	   used	   for	   1977-­‐1981	   and	   applied	   it	   to	   the	   finfish	   catch	   for	   all	   years	   prior.	  	  Subsequently,	   the	   ratios	   from	  the	  species	  composition	  available	   from	  the	  most	   recent	  years	  (i.e.,	  2004-­‐2010	  CDF	  export	  data)	  were	  applied	  to	  the	  catch	  since	  1981	  for	  years	  where	  the	  composition	  was	  unknown.	  	   For	  each	  year,	   the	  total	  annual	  calculated	  consumption	  was	  used	  to	  determine	  an	   approximate	   exported	   catch.	   Between	   1950-­‐1970,	   it	   was	   determined	   that	   finfish	  catches	   were	   95%	   exported,	   compared	   to	   49%	   exported	   for	   the	   last	   two	   decades.	  However,	   given	   the	   way	   in	   which	   total	   consumption	   was	   calculated,	   this	   value	   is	   a	  coarse	  approximation.	  	  Sea	  cucumber	  	   Sea	   cucumber	   catches	   were	   obtained	   from	   a	   variety	   of	   sources,	   namely:	  Bremner	   and	   Perez	   (2002),	   Shepherd	   et	   al.	   (2004),	   Reyes	   and	   Murillo	   (2007),	   Toral-­‐Granda	  (2008)	  and	  Wolff	  et	  al.	  (2012).	  When	  a	  range	  was	  given,	  the	  authors’	  preferred	  value	  was	  used.	  An	  average	  weight	  of	  271	  g	  (Sonnenholzner	  1997)	  was	  used	  to	  calculate	  tonnage	   in	  cases	  where	  the	  original	  data	  referred	  to	  the	  number	  of	   individuals	  caught	  rather	   than	   total	   weight.	   Some	   data	   were	   available	   for	   illegal	   catches	   of	   I.	   fuscus	  (Shepherd	  et	  al.	  2004)	  and	  linear	  interpolation	  was	  used	  between	  these	  anchor	  points.	  Hearn	   and	   Pinillos	   (2006)	   suggest	   that	   illegal	   fishing	   for	   the	   warty	   sea	   cucumber	   (S.	  horrens)	  began	   in	   2004,	   and	   an	   illegal	   catch	   estimate	  was	   determined	   from	   this	   time	  	   26	  onward	   using	   the	   annual	   average	   of	   known	   seizures.	   	   Unfortunately,	   very	   little	  qualitative	   information	  and	  no	  quantitative	  data	  were	  found	  for	  the	  other	  two	  species	  (Holothuria	  atra	  and	  H.	  kefersteini)	  fished	  illegally	  in	  the	  archipelago.	  	  Spiny	  and	  slipper	  lobster	  	   FAO	  data	  show	   landings	   for	  only	  one	  species	  of	   lobster	   (P.	  gracilis);	  however	   it	  was	  assumed	  that	  these	  data	  were	  meant	  to	  include	  P.	  penicillatus	  as	  well.	   It	  was	  also	  assumed	   that	   all	   FAO	   lobster	   data	   referred	   exclusively	   to	   Galápagos	   catches	   (i.e.,	   no	  lobsters	   from	  mainland	   Ecuador)	   since	   the	   fishery	   in	   the	   archipelago	   has	   contributed	  roughly	   90-­‐95%	   to	   Ecuadorian	   catches	   since	   its	   establishment.	   These	   FAO	   data	   were	  largely	   accepted	   to	   be	   correct.	   However,	   additional	   catches	   (‘ad-­‐ons’)	   for	   1973-­‐1976	  were	  obtained	   from	  Reck	   (1983),	  Hearn	  and	  Murillo	   (2008)	   for	  1995-­‐2003,	  and	  export	  data	  provided	  by	  the	  Charles	  Darwin	  Foundation	  (CDF)	  for	  2004-­‐201012.	   In	  most	  cases,	  lobster	  weight	  was	   given	   in	   terms	   of	   tail	  weight,	   thus	   a	   conversion	   factor	   of	   2.86	   (as	  determined	   by	   Reck	   1983)	   was	   used	   to	   calculate	   live	   animal	   weight.	   Most	   sources	  provided	  a	  species	  breakdown;	  when	  this	  was	  unavailable,	  an	  approximate	  species	  catch	  composition	   of	   45%	   P.	   penicillatus,	   45%	   P.	   gracilis,	   and	   10%	   S.	   astori	   was	   used	   for	  catches	  prior	  to	  2000,	  based	  on	  the	  information	  provided	  by	  Bustamante	  et	  al.	  (2000).	  An	   approximate	   catch	   composition	   for	   the	   last	   decade	   was	   adjusted	   based	   on	  information	  in	  Hearn	  and	  Murillo	  (2008),	  which	  suggests,	  “P.	  penicillatus	  makes	  up	  over	  75%	   of	   the	   yearly	   spiny	   lobster	   catch”.	   Available	   information	   was	   used	   to	   estimate	  export	  percentages,	   such	   that	  prior	   to	  1982,	  95%	  of	   spiny	   lobster	  was	  exported	   (Reck	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  12From:	  http://www.galapagospark.org/boletin.php?noticia=354	  [accessed	  16	  July	  2012].	  	   27	  1983),	  92%	  was	  exported	  in	  the	  1990s	  (Busamante	  et	  al.	  2000),	  and	  between	  and	  2000-­‐2010,	  88%	  was	  exported	  (Castrejón	  2011).	  Tuna	  (industrial)	  	   	  Although	   the	   Inter-­‐American	   Tropical	   Tuna	   Commission	   (IATTC)	   has	   published	  various	   reports	   on	   tuna	   caught	   in	   the	   eastern	   Pacific	   since	   the	   1950s,	   a	   lack	   of	  information	  pertaining	  to	  the	  country	  fishing	  made	  it	  impossible	  to	  deduce	  how	  much	  of	  this	   tuna	  was	  caught	   in	   the	  Galápagos	  by	  Ecuador’s	   industrial	   fleet.	  As	   such,	  only	   two	  data	  sets	  (Jácome	  and	  Ospina	  1999;	  Bedoya	  2009)	  for	  three	  species	  (skipjack,	  yellowfin,	  and	   bigeye)	   of	   Ecuador-­‐caught	   tuna	   in	   the	   Galápagos	   could	   be	   found.	   Similar	   to	   the	  spiny	  lobster	  and	  sea	  cucumber	  fisheries,	  it	  was	  assumed	  that	  industrially	  caught	  tuna	  in	  the	   Galápagos	   was	   included	   with	   Ecuador’s	   FAO	   data.	   Ecuador’s	   tuna	   catches	   were	  accepted	   as	   accurate	   and	   two	   time	   series	  were	   used	   to	   estimate	  what	   proportion	   of	  Ecuador’s	  tuna	  was	  from	  the	  Galápagos.	  Since	  it	  closely	  matched	  Bustamante’s	  	  (1999)	  suggestion	   that	   24.3%	   of	   Ecuador’s	   tuna	   comes	   from	   the	   Galápagos,	   the	   percentage	  breakdown	  from	  Bedoya	   (2009)	  was	  used	  to	  determine	  the	  total	  Galápagos	  catch	  and	  species	  composition	  for	  all	  years	  in	  which	  data	  were	  unavailable.	  Sharks	  	   Based	  on	  anecdotal	  evidence,	  1950	  was	  used	  as	  the	  starting	  year	  for	  this	  fishery.	  Estimates	  of	  sharks	  caught	  in	  the	  Galápagos	  were	  obtained	  primarily	  by	  calculating	  the	  difference	  between	   the	   reconstructed	   shark	  catch	  of	  mainland	  Ecuador	  and	  Ecuador’s	  shark	   exports	   from	   1979-­‐2004,	   as	   determined	   by	   Jacquet	   et	   al.	   (2008).	   Information	  	   28	  suggests	  that	  the	  extent	  of	  shark	  fishing	  that	  occurred	  in	  the	  past	  was	  not	  as	  substantial	  as	  it	  is	  presently.	  However,	  since	  no	  estimates	  were	  available,	  the	  first	  available	  data	  set	  (from	  1979-­‐1984)	  was	  averaged	  and,	  to	  keep	  early	  estimates	  conservative,	  15%	  of	  this	  catch	  was	   applied	   to	   1970.	   Subsequently,	   linear	   interpolation	   between	   1950	   and	   this	  anchor	   point	  was	   used	   to	   approximate	  missing	   catches.	   There	   are	   no	   quantitative	   or	  anecdotal	   indications	   that	   shark	   finning	   ever	   declined	   or	   stopped	   in	   the	   Galápagos.	  Thus,	   when	   export	   data	   from	   Jacquet	   et	   al.	   (2008)	   were	   less	   than	   Ecuador’s	  reconstructed	  catch,	  it	  was	  still	  assumed	  shark	  fishing	  was	  occurring	  in	  the	  archipelago,	  but	   that	   exports	   during	   this	   time	   were	   under-­‐reported	   and	   a	   linear	   interpolation	  between	  these	  years	  was	  used	  instead.	  	  	   A	  species	  breakdown	  was	  determined	  from	  the	  Fundaciόn	  Natura-­‐World	  Wildlife	  Fund’s	   Galápagos	   Report	   (WWF	   1998)	   which	   states	   that	   “the	   main	   shark	   species	  captured	   in	  Galápagos	   in	  1994	  were	   the	  blue	   (P.	  glauca),	   accounting	   for	  67.2%	  of	   the	  catch;	  the	  thresher	  (A.	  vulpinus	  and	  A.	  superciliosus),	  at	  13.2%	  of	  the	  catch;	  the	  Mico13	  at	  15.6%;	  and	   the	  hammerhead	   (Sphyrna	   spp.),	   at	   2.3%.”	  Although	   these	  percentages	  refer	  to	  only	  one	  year,	  this	  breakdown	  appears	  consistent	  with	  anecdotes	  in	  Jacquet	  et	  al.	   (2008),	   which	   suggest	   that	   blue	   sharks	   and	   thresher	   sharks	   currently	   constitute	  nearly	  90%	  of	  all	  shark	  landings	  in	  the	  ‘shark	  mafia’	  epicenter	  of	  Manta,	  Ecuador.	  	  Trophic	  level	  analysis	  	   Given	   reported	   quantitative	   and	   qualitative	   changes	   in	   catch	   composition,	   the	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  13Silky	  shark	  (Carcharhinus	  falciformes)	  	   29	  mean	  trophic	  level	  (TL)	  of	  the	  artisanal	  catch	  was	  also	  analysed	  to	  see	  if	  ‘fishing	  down’14	  was	  occurring	  (i.e.,	  if	  there	  were	  any	  noticeable	  ecological	  shifts	  in	  the	  species	  landed	  	  Table	  2-­‐2.	  Trophic	  level	  (TL)	  of	  commonly	  caught	  finfish	  and	  invertebrates	  of	  the	  Galápagos	  Islands.	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  14Here,	   ‘fishing	  down’	   is	   defined	  as	   a	  decline	   in	   the	  mean	   trophic	   level	  of	   fisheries	   catches,	   reflecting	  a	  decline	   of	   higher-­‐trophic	   level	   (predatory)	   species,	   relative	   to	   species	   low	   in	   food	   webs,	   such	   as	  planktivores	  (e.g.,	  mullets)	  and	  detritivores	  (e.g,	  sea	  cucumbers). !Habitat& Family& English&name& Spanish&name& Latin&name& TL&In#shore)))Serranidae)Galápagos)grouper)Bacalao) Mycteroperca*olfax* 4.4)Misty)grouper) Mero) Epinephelus*mystacinus* 4.4)#) Camotillo) Paralabrax*albomaculatus*4.4)Starry)grouper) Cabrilla) Epinephelus*labriformis* 4.0)Leather)bass) Cagaleche) Dermatolepis*dermatolepis*4.4)Olive)grouper) Norteño) Epinephelus*cifuentesi* 4.0)Mugilidae)Galápagos)mullet) Lisa)rabo)amarillo)Mugil*galapagensis* 3.0)Thoburn's)mullet) Lisa)rabo)negro) Xenomugil*thoburni* 2.9)Labridae) Galápagos)sheephead)wrasse)Vieja)mancha)dorada)Semicossyphus*darwini* 3.6)Hemilutjanidae) Grape#eye)seabass)Ojón/Ojo)de)uva) Hemilutjanus*macrophthalmos*3.8)Scorpaenidae) #) Brujo) Scorpaena)spp.* 3.5)Malacanthidae) Ocean)finfish) Blanquillo) Caulolatilus*princeps* 3.9)Lutjanidae) Pacific)cubera)snapper)Pargo)mulato/)pargo)rojo)Lutjanus*novemfasciatus* 3.7)Palinuridae)Red)spiny)lobster) Langosta)roja) Panulirus*penicillatus* 2.8)Blue)spiny)lobster) Langosta)verde) Panulirus*gracilis* 2.8)Scyllaridae) Slipper)lobster) Langostino) Scyllarides*astori** 2.7)Stichopodidae) Brown)sea)cucumber)Pepino)de)mar) Isostichopus*fuscus* 2.1)Off#shore))Scombridae))Wahoo) Guajo) Acanthocybium*solandri* 4.2)Bigeye)tuna) Atún)patudo/)atún)ojo)grande)Thunnus*obesus* 4.2)Yellowfin)tuna) Atún)aleta)amarilla)Thunnus*albacares* 4.2)Pacific)sierra) Sierra) Scomberomorus*sierra)* 4.2)Albacore)tuna) Albacora) Thunnus*alalunga* 4.2)Carangidae)Longfin)yellowtail) Palometa) Seriola*rivoliana* 4.2)Steel)pompano) Pampano)acerado)Trachinotus*stilbe* 3.8)Xiphiidae) Swordfish) Pez)espada) Xiphias*gladius* 4.5)	   30	  over	   time).	   Although	   still	   caught	   by	   Ecuadorian	   vessels	   in	   the	   Galápagos	   EEZ	   (i.e.	  Ecuadorian	  waters),	  we	  chose	   to	  omit	   industrially	  and	   illegally	  caught	   tuna	  and	  sharks	  from	  this	  analysis	  since	  these	  species	  are	  not	  directly	  related	  to	  the	  fisheries	  and	  fishers	  of	  the	  Galápagos.	  	  	  	   We	   used	   the	   average	   of	   the	   TL	   values	   provided	   by	   Okey	   et	   al.	   (2004)	   and	  FishBase	   (www.fishbase.org)	   for	   fishes,	   and	   SeaLifeBase	   (www.sealifebase.org)	   for	  invertebrates	  (Table	  2-­‐2).	  However,	  since	  the	  fishing	  down	  effect	  can	  be	  easily	  masked	  by	  aggregating	  data	  from	  different	  ecosystems,	  we	  defined	  an	  ‘in-­‐shore’	  ecosystem	  that	  comprised	  all	  species	  typically	  occurring	  along	  the	  coast,	  or	  within	  the	   in-­‐shore	  fishing	  area	   (i.e.,	   to	   50	   km	   from	   the	   coast	   or	   200	  m	   deep).	   Given	   the	   instability	   and	   innate	  boom-­‐and-­‐bust	  nature	  of	   the	   sea	   cucumber	   fishery,	  we	  also	   chose	   to	  perform	   the	   in-­‐shore	   analysis	   with	   and	   without	   sea	   cucumbers.	   The	   separate	   ‘off-­‐shore’	   species	  category	  refers	  to	  larger	  pelagic	  fishes	  that	  would	  typically	  be	  found	  outside	  of	  the	  IFA	  (Table	  2-­‐2).	  We	  used	  the	  average	  TL	  value	  (3.54)	  of	  all	  species	  in	  this	  analysis	  for	  finfish	  landings	   that	  could	  not	  be	  disaggregated	  by	  species	   (i.e.,	   the	   ‘others’),	  and	  kept	   these	  fish	   in	   both	   spatial	   categories.	   Regression	   analyses	   were	   performed	   to	   assess	   the	  changes	  in	  mean	  trophic	  level	  over	  time.	  RESULTS	  AND	  DISCUSSION	  	   Although	   primarily	   established	   within	   the	   last	   sixty	   years,	   this	   catch	  reconstruction	   demonstrates	   a	   relatively	   high	   level	   of	   overexploitation	   within	   the	  commercial	   fisheries	   of	   the	   Galápagos,	   particularly	   with	   regard	   to	   sea	   cucumber	   and	  spiny	  lobster.	  Of	  additional	  concern	  is	  the	  decline	  in	  abundance	  of	  large	  apex-­‐level	  fish,	  31	  such	  as	  the	  groupers,	  and	  the	  subsequent	  changes	  in	  catch	  composition	  that	  followed.	  Given	  that	  no	  cumulative	  baseline	  data	  set	  from	  either	  the	  FAO	  or	  Government	  of	  Ecuador	  was	  available	   for	   the	  Galápagos,	  we	  are	  unable	   to	  give	  a	   total	   comparison	  between	   landings	   reported	   to	   the	   FAO	   and	   those	   presented	   in	   this	   reconstruction.	  Nonetheless,	  when	  taking	  into	  account	  all	  legal	  and	  illegal	  fisheries	  in	  the	  Galápagos,	  we	  determined	  that	  from	  1950-­‐2010,	  a	  total	  of	  797,000	  t	  of	  seafood	  was	  extracted	  from	  the	  EEZ	  surrounding	  this	  archipelago.	  It	  should	  be	  recognized	  that	  80%	  of	  these	  landings	  are	  tuna	  caught	  by	  Ecuador’s	  industrial	  fleet,	  and	  shark	  fishing—which	  is	  currently	  illegal—is	  the	  second	  highest	  contributing	  fishery,	  accounting	  for	  13%	  of	  these	  landings.	  These	  and	  additional	  sector	  breakdowns	  are	  discussed	  below.	  Local	  consumption	  Since	   spiny	   sea	   cucumbers	   are	   entirely	   exported,	   locally	   consumed	   seafood	   is	  composed	  of	  finfish	  species	  (including	  tuna),	  slipper	  lobster	  and	  a	  small	  amount	  of	  spiny	  lobster.	   Given	   the	   increased	   residency	   and	   tourism	   on	   the	   Galápagos,	   it	   is	  understandable	   that	   there	   has	   also	   been	   an	   increase	   in	   the	   amount	   of	   seafood	  consumed	  on	  the	  Islands.	  From	  1950	  to	  2010,	  we	  estimate	  that	  6,700	  t	  of	  finfish,	  700	  t	  of	  slipper	  lobster,	  and	  600	  t	  of	  spiny	  lobster	  were	  consumed	  by	  locals	  on	  the	  Islands.	  The	  aforementioned	  per	   capita	   seafood	   consumption	   rates	   are	   very	   low	   in	   comparison	   to	  other	   oceanic	   islands	   and	   countries	   (see	   Jones	   2013).	   However,	   this	   disparity	   is	   likely	  due	   to	   the	   prominence	   of	   agricultural	   and	   farmland	   on	   the	   islands;	   many	   Galápagos	  residents	  maintain	  a	  diet	  similar	  to	  that	  of	  people	  on	  the	  mainland,	  consuming	  primarily	  grains	  and	  meat.	  	  32	  Bacalao	  and	  finfish	  Between	   1950	   and	   2010,	   artisanal	   fishers	   in	   the	  Galápagos	   landed	   26,500	   t	   of	  finfish,	  of	  which	  approximately	  75%	  has	  been	  exported.	  Most	  significant	  to	  this	  finding	  is	  not	  the	  tonnage,	  but	  rather	  the	  changes	  in	  species	  composition	  that	  have	  occurred	  over	  the	  years	  (Figure	  2-­‐1).	  Between	   1977-­‐1981,	   M.	   olfax	   constituted	   36%	   of	   the	   annual	  finfish	   catch	   and,	   in	   general,	   serranids	  made	   up	   89%	   (Reck	   1983).	   Despite	   the	   finfish	  fishery’s	  simple	  origins,	  catches	  today	  are	  from	  two	  distinct	  spatial	  groups	  (in-­‐shore	  and	  off-­‐shore),	  and	  include	  68	  different	  species	  from	  27	  families	  (Castrejón	  2011).	  Between	  1997	   and	   2001,	   the	   finfish	   fishery	   was	   primarily	   composed	   (41%)	   of	   two	   mullets:	   X.	  thoburni	   and	  M.	  galapagensis	   (Andrade	   and	  Murillo	   2002),	   species,	  which,	   during	   the	  Figure	  2-­‐1.	  Reconstructed	  Galápagos	  artisanal	   finfish	   catch	   (1950-­‐2010),	  by	   family.	  Prior	  to	  the	  1980s,	  the	  bulk	  of	   landings	  were	   composed	  of	   large,	  predatory	   in-­‐shore	   serranids	   (e.g.,	   groupers;	   in	  particular	  Mycteroperca	  olfax).	  Over	  the	  last	  two	  decades,	  the	  species	  composition	  has	  changed	  such	  that	  off-­‐shore	  species	   (e.g.,	   tuna)	  and	  smaller	   in-­‐shore	   forage	   fish	   (e.g.,	  mullets)	  are	  now	  much	  more	  prevalent	   in	   the	  catch.	  	   33	  1970s,	  were	  only	   fished	  occasionally.	  During	  this	   time,	  mullets	  were	  not	  exported	  and	  were	   consumed	   locally	   as	   subsistence,	   or	   used	   as	   bait	   for	   larger	   fish	   (Reck	   1983).	  Between	  2000	  and	  2010,	  M.	  olfax	  constituted	  only	  17%	  of	  the	  total	  catch,	  and	  another	  endemic	  serranid,	  Paralabrax	  albomaculatus,	  which	  made	  up	  32%	  of	  the	  catch	  between	  1977-­‐1981	   (Reck	   1983),	   made	   up	   only	   3%	   between	   2000-­‐2010.	   It	   is	   also	   particularly	  troublesome	  to	  note	  that,	  although	  only	  scientifically	  described	  in	  1993	  (Lavenberg	  and	  Grove	  1993),	  Epinephelus	  cifuentesi	  was	  fished	  so	  heavily	  that	  the	  average	  annual	  catch	  fell	   by	   80%	   between	   1998	   and	   2003	   (Nicolaides	   et	   al.	   2002).	   As	   such,	   the	   Galápagos	  population	  of	  this	  grouper	  is	  currently	  listed	  as	  ‘Vulnerable’	  under	  the	  IUCN	  (Rocha	  et	  al.	  2008).	  	  	   In	   addition	   to	   the	   mullets,	   coastal	   pelagics	   such	   as	   wahoo	   (Acanthocybium	  solandri)	  and	  pomfret	  (Seriola	  rivoliana)	  have	  taken	  on	  increased	  economic	  importance	  (Reck	  1983),	  which	  is	  reflected	  by	  an	  increasing	  prominence	  in	  current	  catches.	  With	  a	  total	   landing	   of	   840	   t	   over	   sixty	   years,	   artisanal-­‐caught	   tuna	   in	   the	   Galápagos	  contributes	  a	  very	  small	   fraction	   (0.1%)	   to	   the	   total	   tuna	  caught	   in	   this	  EEZ.	  However,	  given	   the	   observed	   decline	   in	   the	   abundance	   of	   M.	   olfax	   within	   the	   GMR,	   the	  importance	  of	  tuna	  in	  the	  finfish	  fishery	  will	  likely	  continue	  to	  increase.	  	  	  Sea	  cucumber	  Taiwan	  and	  Hong	  Kong	  are	  the	  primary	  importers	  of	  sea	  cucumber,	  and	  between	  2005-­‐2006,	  they	  accounted	  for	  83%	  of	  exported	  dried	  sea	  cucumber	  from	  the	  Galápagos	  (Toral-­‐Granda	  2008).	  Given	  that	  a	  kilogram	  of	  dried	  sea	  cucumber	  can	  fetch	  as	  much	  as	  US$170	   in	   Asia	   (Castrejón	   2011),	   lucrative	   financial	   incentives	   promoted	   by	   global	  	   34	  demand	  have	  generated	  both	  a	   substantial	   legal	  and	   illegal	   take	  of	   this	   resource.	  This	  reconstruction	  determined	  that	  16,100	  t	  of	  sea	  cucumber	  was	  caught	  in	  the	  Galápagos	  between	  1950	  and	  2010.	  Of	  this,	  13,000	  t	  was	  legally	  caught	  I.	  fuscus	  and	  the	  rest	  illegal	  catch	  of	  both	  I.	  fuscus	  (3,060	  t)	  and	  S.	  horrens	  (40	  t).	  This	  reconstructed	  catch	  is	  36	  times	  as	  much	  as	   Ecuador’s	   reported	   landings	  of	   sea	   cucumber	   to	   FAO	   for	   the	   same	  period	  (Figure	  2-­‐2).	  The	  largest	  annual	  catch	  of	  I.	  fuscus	  (2,800	  t)	  occurred	  in	  1994,	  just	  prior	  to	  the	  four-­‐year	  closure	  of	  this	  fishery	  (when	  it	  was	  still	  largely	  unregulated).	  	  	  	  Figure	   2-­‐2.	   Total	   reconstructed	   sea	   cucumber	   catch	   for	   the	   Galápagos	   archipelago,	   1950-­‐2010.	   An	  estimated	   13,000	   t	   of	   the	   brown	   sea	   cucumber	   (Isostichopus	   fuscus)	   were	   legally	   gathered	   for	   export	  since	   the	   establishment	   of	   the	   fishery;	   30	   times	   as	  much	   as	   reported	  by	   the	   FAO	   (dashed	   line)	   for	   the	  same	  time	  period.	  An	  additional	  3,000	  t	  of	  this	  species	  has	  been	  illegally	  taken,	  primarily	  between	  1994	  and	  1999.	  The	  reconstructed	  illegal	  catch	  of	  the	  warty	  sea	  cucumber	  (Stichopus	  horrens)	  is	  an	  estimated	  40	  t.	   	  	  	   35	  	   When	   the	   brown	   sea	   cucumber	   fishery	   was	   closed	   following	   the	   initial	   and	  unsustainable	   boom	   in	   1991,	   extensive	   illegal	   fishing	   was	   undertaken	   to	   continue	  exporting	   this	   species	   to	   the	   Asian	   seafood	   and	   aphrodisiac	   market	   (Deborah	  Chiriboga15,	   pers.	   comm.).	   Although	   both	   H.	   atra	   and	   H.	   kefersteini	   are	   also	   fished	  illegally	   in	   the	   Galápagos	   (Toral-­‐Granda	   2008),	   no	   annual	   catch	   estimations	   could	   be	  found	  and	  therefore	  these	  species	  are	  excluded	  from	  this	  reconstruction.	  Therefore,	  and	  given	   that	   the	   illegal	   catch	   estimates	   are	   based	   only	   on	   known	   seizures,	   the	   total	  tonnage	  for	  illegal	  sea	  cucumber	  landings	  is	  likely	  highly	  conservative.	  	  Given	   substantial	   declines	   in	   I.	   fuscus	   (Toral-­‐Granda	   2008),	   there	   have	   been	  suggestions	  for	   legalizing	  the	  fishery	  for	  S.	  horrens,	  as	  well	  as	   for	  the	  white	  sea	  urchin	  (Tripneustes	  depresus)	  (Castrejón	  2011).	  Although	  these	  initiatives	  have	  the	  potential	  to	  provide	   short-­‐term	   economic	   benefits,	   this	   shift	   in	   targeted	   species	   is	   not	   unlike	   the	  mainland	  to	  Galápagos	  sea	  cucumber	  boom-­‐and-­‐bust	  scenario	  of	  the	  1990s.	  As	  such,	  if	  management	  and	  enforcement	  were	  the	  same	  as	  with	  I.	  fuscus,	  similar	  stock	  depletion	  of	  these	  other	  two	  invertebrates	  should	  be	  anticipated.	  Spiny	  and	  slipper	  lobster	  	   This	  reconstruction	  determined	  that	  since	  1950,	  9,200	  t	  of	  spiny	  lobster	  has	  been	  extracted	  from	  the	  EEZ	  of	  the	  Galápagos.	  While	  the	  FAO	  spiny	  lobster	  data	  for	  the	  past	  appear	   to	   be	   accurate,	   the	   reconstructed	   catch	   of	   P.	   penicillatus	   and	   P.	   gracilis	  was	  400%	   higher	   than	   the	   FAO	   data	   from	   1995-­‐2010;	   this	   underreporting	   may	   be	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  15Former	  Executive	  Director	  of	  Fundación	  Natura	  in	  Ecuador,	  a	  Latin	  American	  non-­‐governmental	  organization	  working	  to	  bridge	  the	  gap	  between	  communities,	  organizations,	  and	  businesses	  in	  an	  environmentally	  sustainable	  way.	  	  36	  attributable	  to	  changes	  in	  reporting	  structure	  in	  the	  region.	  The	  notable	  decrease	  in	  the	  total	  catch	  of	  spiny	  lobsters	  since	  2000	  (Figure	  3-­‐3)	  is	   likely	   a	   result	   of	   the	   aforementioned	   changes	   in	   their	   abundance.	  Declines	   in	   spiny	  lobster	  have	  additionally	  been	  linked	  to	  an	  increased	  presence	  of	  sea	  urchins	  in	  the	  sub-­‐tidal	   zone.	   As	   a	   result	   of	   this	   competitive	   release,	   sea	   urchin	   cover	   has	   dramatically	  increased	   (Banks	   2007),	   contributing	   to	   reduced	   growth	   and	   coverage	   of	  macroalgae	  and	  corals—habitats	  that	  were	  once	  prevalent	  in	  the	  waters	  surrounding	  the	  Galápagos.	  At	  present,	  only	  5%	  of	  the	  original	  macroalgae	  beds	  remain	  and,	  in	  combination	  with	   the	   impact	   of	   the	   urchins,	   these	   threatened	   environments	   are	   under	   additional	  stress	  due	  to	  the	  effects	  of	  climate	  change	  (Banks	  2007).	  These	  habitats	  play	  a	  key	  role	  in	   the	   archipelago	   and,	   as	   Castrejón	   (2011)	   explains,	   “their	   disappearance	   is	  worrying	  because	  of	  their	  direct	  effect	  on	  the	  distribution	  and	  abundance	  of	  many	  other	  species	  that	  depend	  on	  them	  as	  sources	  of	  food,	  shelter,	  and	  reproduction”16.	  Given	   the	   current	   state	   of	   the	   spiny	   lobster	   fishery,	   there	   has	   been	   increased	  pressure	  to	  allow	  the	  export	  of	  slipper	  lobster	  (S.	  astori)	  as	  well	  (Hearn	  2006).	  However,	  Hearn	  (2006)	  recommends	  a	  cautious	  approach,	  as	  the	   life	  history	  characteristics	  of	  S.	  astori,	   combined	   with	   the	   past	   overexploitation	   of	   many	   Galápagos	   fisheries	   suggest	  that	  this	  species	  could	  be	  at	  a	  heightened	  risk	  of	  overexploitation.	  16Translated	  from	  Spanish.	  	   37	  	  Figure	   2-­‐3.	   Reconstructed	   catch	   of	   spiny	   and	   slipper	   lobsters	   for	   the	   Galápagos,	   1950-­‐2010.	  Approximately	  9,200	  t	  of	  spiny	  lobster	  (Panulirus	  penicillatus	  and	  P.	  gracilis)	  and	  700	  t	  of	  slipper	   lobster	  (Scyllarides	  astori)	  were	   caught	  within	   the	  EEZ	  of	   the	  Galápagos	   from	  1950	   to	  2010.	   The	   reconstructed	  catch	  of	  P.	  penicillatus	  and	  P.	  gracilis	  was	  400%	  higher	  than	  reported	  by	  the	  FAO	  (dashed	  line)	  between	  1995	  and	  2010.	  Tuna	  (industrial)	  	   This	  reconstruction	  estimated	  that	  within	  the	  Galápagos	  EEZ,	  Ecuador’s	  industrial	  fishery	  caught	  639,000	  t	  of	  tuna	  between	  1950	  and	  2010,	  with	  skipjack	  constituting	  68%	  of	  this	  catch,	  followed	  by	  yellowfin	  (23%)	  and	  bigeye	  (9%).	  	  Tuna	  fisheries	  in	  the	  Pacific	  Ocean	  contribute	  over	   two-­‐thirds	  of	   the	  world’s	  annual	   tuna	  catch	   (Sibert	  et	  al.	  2006)	  and	   Ecuador	   is	   the	   primary	   tuna	   fishing	   country	   in	   the	   EPO	   (IATTC	   2011).	   Given	   this	  heavy	   fishing	  pressure,	   it	   is	   not	   surprising	   that	   in	   2006,	   the	   IATTC	   listed	   the	   yellowfin	  stock	   as	   fully	   exploited	   and	   bigeye	   as	   overexploited	   (Castrejón	   2011).	   In	   response	   to	  these	   concerns,	   the	   IATTC	   imposed	   a	   range	   of	   fishing	   restrictions	   on	   its	   member	  countries,	   including	   a	   closure	   of	   the	   Ecuadorian	   purse	   seine	   fishery	   in	   August	   and	  	   38	  September	   2007	   and	   setting	   a	   recent	   total	   allowable	   catch	   (TAC)	   of	   500	   t	   for	   their	  industrial	  longline	  fleet	  (Castrejón	  2011).	  While	  these	  efforts	  should	  not	  be	  overlooked,	  continued	  management	  will	   be	   required	   for	   the	   long-­‐term	  health	  of	   these	   stocks	   and	  their	  associated	  fisheries.	  	  	  	   Although	   no	   catch	   estimates	   were	   available	   for	   illegal	   industrial	   tuna	   fishing,	  these	   illicit	   activities	  are	  an	  ongoing	  problem	  within	   the	  waters	  of	   the	  GMR.	  Between	  1989	  and	  1996,	  48	  vessels	  (both	  Ecuadorian	  and	  foreign)	  were	  caught	  illegally	  fishing	  for	  tuna	   (Altamirano	  and	  Aguiñaga	  2002).	   Subsequently,	   from	  1996-­‐1998,	  119	   tuna	  boats	  were	  either	   caught	  or	  observed,	  although	   this	  decreased	   to	  a	   total	  of	  61	  boats	   in	   the	  following	  six	  years	  (Reyes	  and	  Murillo	  2007).	  These	  vessels	  are	  primarily	  purse-­‐seiners.	  However,	  some	  also	  use	   longlines,	  a	   largely	  non-­‐selective	   technique	  that	  catches	  both	  targeted	  marine	  life,	  and	  untargeted	  species	  (e.g.	  other	  fishes,	  sea	  turtles,	  seabirds)	  as	  well.	   Gales	   (2007)	   suggests	   that	   “the	   best	   available	   evidence	   indicates	   that	  longline	  fishing	   is	   the	  most	  serious	   threat	   facing	  albatrosses	   today”—	  a	  statement	   that	   is	  even	  more	   applicable	   in	   the	   Galápagos	   since	   the	   ‘Critically	   Endangered’17	  Waved	   albatross	  (Phoebastria	  irrorata)	  breeds	  almost	  exclusively	  on	  Española	  Island	  (Merlen	  1998).	  Sharks	  	  	  As	   suggested	   by	   Jacquet	   et	   al.	   (2008),	   the	   underreporting	   of	   shark	   catches	   in	  Ecuador	   is	  substantial.	   It	  was	  determined	  that,	  since	  1950,	  approximately	  105,600	  t	  of	  shark	   has	   been	   caught	   in	   the	   Galápagos	   Islands	   by	   the	   Ecuadorian	   fleet;	   the	   highest	  catch	   (7,050	   t)	   was	   in	   2000.	   If	   it	   is	   assumed	   that	   the	   sharks	   are	   caught	   at	   half	   the	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  17From:	  http://www.iucnredlist.org/details/106003955/0	  [accessed	  8	  August	  2012].	  39	  maximum	  weight	  reached	  in	  their	  species,	  the	  tonnage	  converts	  to	  a	  very	  conservative	  estimate	  of	  112,000	  individual	  sharks	  caught	  by	  Ecuador	  alone	  in	  that	  year18.	  Therefore,	  despite	   attempts	   to	   mitigate	   the	   amount	   of	   shark	   fishing	   occurring	   in	   these	   waters,	  government	   and	   policy	   failures,	   and	   the	   imperfections	   of	   open	   access	   markets	  encouraged	   by	  millions	   of	   dollars,	   have	   allowed	   this	   unacceptable	   traffic	   to	   continue,	  thus	   violating	   and	   ignoring	   both	   the	   Special	   Law	   of	   Galápagos	   and	   the	   conservation	  goals	   of	   the	   GMR.	   In	   addition	   to	   fishing	   by	   Ecuador,	   foreign	   boats	   from	   Costa	   Rica,	  Columbia,	  and	  Japan	  are	  also	  known	  to	  fish	  for	  sharks	  in	  Galápagos	  waters	  (Watts	  and	  Wu	   2005;	   Reyes	   and	   Murillo	   2007).	   As	   such,	   this	   reconstruction	   likely	   shows	   only	   a	  fraction	  of	  the	  total	  illegal	  shark	  fishing	  (and	  finning)	  occurring	  in	  the	  archipelago.	  Carr	   et	   al.	   (2013)	   recently	   documented	   that	   of	   379	   sharks	   taken	   by	   an	   illegal	  Ecuadorian	   longlining	  vessel	   in	  2011,	  80%	  were	  bigeye	  thresher	  (A.	  superciliosus),	  11%	  were	  silky	  (C.	  falciformes),	  and	  only	  6%	  were	  blue	  (P.	  glauca).	  Although	  these	  numbers	  refer	   to	   one	   isolated	   seizure,	   there	   is	   a	   notable	   difference	   in	   the	   catch	   composition	  when	   compared	   to	   the	   species	   breakdown	   used	   in	   this	   study.	   At	   an	   ecosystem	   level,	  these	   findings	   may	   therefore	   reflect	   a	   change	   in	   abundance	   of	   certain	   species,	  specifically	  a	  decline	  in	  blue	  sharks.	  The	  main	  incentive	  for	  shark	  fishing	  and	  finning	  in	  the	  last	  decade	  has	  been	  the	  demand	   from	   mainly	   East	   Asian	   markets,	   and	   Hong	   Kong	   in	   particular	   (Clarke	   et	   al.	  2007).	  Although	  tasteless,	  cartilaginous	  shark	  fins	  can	  cost	  upward	  of	  $400/	  kg	  (Jacquet	  et	   al.	   2008)	   and	   are	   the	   principal	   ingredient	   in	   fashionable	   sharkfin	   soup.	   With	   an	  18This	   estimate	   is	   conservative	   because	   the	   mean	   weight	   of	   individuals	   in	   an	   exploited	   population	   of	  sharks	  is	  likely	  to	  be	  less	  than	  half	  the	  species’	  maximum	  weights.	  	   40	  estimated	  minimum	  worth	  of	  $400-­‐550	  million	  annually	  (Clarke	  et	  al.	  2007),	  the	  trade	  of	  shark	   products	   is	   a	   very	   lucrative	   global	   industry	   and	   one	   that	   needs	   immediate	   and	  focused	  attention	  in	  Ecuador,	  and	  the	  Galápagos	  in	  particular.	  As	   a	   result	   of	   growing	   concerns	   over	   the	   sustainability	   and	   health	   of	   shark	  populations,	   large-­‐scale	   shark	   fishing	   and	   shark	   fin	   export	  were	   banned	   in	   Ecuador	   in	  1989	  (Official	  Register,	  No.	  194;	  19	  May	  1989)	  and	  2004	  (Executive	  Decree	  2130;	  Official	  Register,	  No.	  437)	  respectively	  (PNG	  2009).	  While	  these	  efforts	  initially	  made	  Ecuador	  a	  world-­‐leader	   in	   protective	   shark	   legislation,	   in	   July	   2007,	   the	   Ecuadorian	  Government	  officially	   enacted	   Executive	   Decree	   486	   (Official	   Record	   137),	   an	   amendment	   to	   the	  previous	  laws.	  This	  amendment	  still	  prohibits	  shark	  finning	  and	  the	  dumping	  of	  sharks	  at	  sea.	  However,	   fishers	  are	  now	  allowed	  to	  trade	  fins	  extracted	  from	  sharks	   incidentally	  caught	   during	   fishery	   activities	   under	   a	   special	   permit	   (Jacquet	   et	   al.	   2008).	  Unfortunately,	  in	  Ecuador,	  ‘incidental	  catch’	  can	  be	  as	  high	  as	  70%	  (Aguilar	  et	  al.	  2007),	  with	   100%	   mortality	   of	   by-­‐caught	   sharks	   (Coello	   et	   al.	   2010),	   and	   this	   loophole	   has	  allowed	   fishers	   to	  continue	   to	   trade	  shark	   fins	  without	   legal	  consequences	   (Carr	  et	  al.	  2013).	   All	   activities	   associated	   with	   shark	   fishing	   were	   completely	   forbidden	   in	  Galápagos	   by	   the	   GNPS	   in	   2000	   (Jacquet	   et	   al.	   2008).	   However,	   given	   that	   between	  2001-­‐2007,	  there	  were	  29	  reported	  seizures	  of	  boats	   illegally	  shark	  fishing	   in	  the	  GMR	  (Carr	  et	  al.	  2013),	  and	  based	  on	  the	  total	  shark	  catch	  determined	  by	  this	  reconstruction,	  the	   effect	   these	   efforts	   have	   had	   on	   actually	   protecting	   sharks	   in	   the	   archipelago	  appears	  to	  be	  negligible.	  	  	   Along	  with	  other	  pelagic	   fish,	   sharks	  play	  a	  vital	   role	  as	  apex	  predators	   in	   top-­‐	   41	  down	   regulated	  marine	  ecosystems	   (Stevens	   et	  al.	   2000;	  Myers	   et	  al.	   2007).	  Using	  an	  ecosystem	  model,	  Okey	  et	  al.	  (2011a)	  predicted	  that	  the	  complete	  removal	  of	  sharks	  in	  the	   Galápagos	   would	   result	   in	   increases	   in	   toothed	   cetaceans,	   sea	   lions,	   and	   non-­‐commercial	   reef	  predators,	  and	  subsequently	   lead	   to	  a	  decrease	   in	  bacalao	  and	  other	  commercially	  valuable	  fish	  species.	  	  Trophic	  level	  analysis	  	   Figure	   4A	   illustrates	   the	   changing	   composition	   of	   artisanal	   fisheries	   catches	  around	   the	   Galápagos	   through	   trends	   of	   the	   mean	   trophic	   levels	   of	   the	   organisms	  landed	   (fish	   and	   invertebrates);	   regression	   analysis	   showed	   a	   significant	   change	   (r2=	  0.59;	   F(1,	   60)=	   85.9;	   p<	   0.001)	   in	   the	   mean	   TL	   between	   1950-­‐2010.	   While	   this	   may	  demonstrate	   a	   very	   strong	   example	   of	   fishing	   down	   at	   a	   cumulative	   level	   (0.23	   TL	  decade-­‐1),	   it	   is	   important	   to	   note	   that	   if	   the	   ecosystem	   is	   ill-­‐defined,	   and	   combines	  species	   that	  do	  not	   interact	  with	  each	  other	   (such	  as	   lobster	   and	   tuna),	   the	  observed	  levels	   of	   fishing	   down	   could	   potentially	   be	   masked	   or	   enhanced.	   Thus,	   the	   overall	  strength	   of	   this	   trend	   will	   be	   a	   function	   of	   the	   extent	   of	   the	   spatial/ecological	   over-­‐aggregation	   error	   that	   is	   committed,	   and	   the	   relative	   catches	   involved.	   Specifically	  worrisome	  is	  that	  if	  only	  an	  aggregate	  mean	  TL	  is	  observed,	  one	  can	  get	  the	  impression	  that	   mean	   trophic	   levels	   in	   the	   catch	   from	   the	   exploited	   ‘ecosystem’	   can	   actually	  increase,	   as	   suggested	   by	   Branch	   et	   al.	   (2010).	   As	   is	   observed	   in	   the	   Galápagos,	   the	  mean	  TL	  of	  the	  catch	  steadily	  declined	  until	  the	  early	  2000s,	  at	  which	  point	  it	  began	  to	  increase	  (see	  Figure	  4A).	  Although	  this	  positive	  trend	  could	  initially	  be	  interpreted	  as	  the	  fishery	   in	   the	   process	   of	   rebuilding,	   in	   reality	   it	   is	   due	   to	   the	   collapse	   of	   the	   sea	  	   42	  	  Figure	  2-­‐4.	  Changes	  in	  mean	  trophic	  level	  (TL)	  of	  the	  artisanal	  catch	  in	  the	  Galápagos	  Islands.	  (A)	  With	  all	  species	  and	  spatial	   scales,	   there	  has	  been	  a	   significant	  decline	   (0.23	  TL	  decade-­‐1)	   in	   the	  mean	  TL	  of	   the	  catch	  from	  1950	  to	  2010,	  much	  of	  which	  is	  attributable	  to	  the	  influence	  and	  fluctuations	  of	  sea	  cucumber	  fishing	  from	  1990	  onward;	  the	  increase	  in	  the	  late	  2000s	  is	  not	  due	  to	  stock	  recovery	  (see	  text).	  (B)	  When	  species	  are	  spatially	  disaggregated,	  the	  mean	  TL	  of	  the	  in-­‐shore	  catch	  (not	  including	  sea	  cucumbers)	  also	  shows	  a	  significant	  decline	  of	  0.12	  TL	  decade-­‐1.	  The	  mean	  TL	  of	  the	  off-­‐shore	  catch	  increases,	  although	  not	  significantly	  over	  time.	  43	  cucumber	  fishery,	  combined	  with	  a	  change	  in	  the	  directed	  efforts	  of	  the	  artisanal	  fleet	  to	  off-­‐shore	  fish	  species,	  rather	  than	  a	  result	  of	  in-­‐shore	  stock	  recovery.	  When	   separating	   the	   artisanal	   catch	   by	   specific	   in-­‐shore	   and	   off-­‐shore	   regions	  (see	   Figure	   4B),	   it	  was	   found	   that	   (even	  when	   excluding	   sea	   cucumbers)	   the	   in-­‐shore	  mean	  TL	  has	  declined	  significantly	   from	  4.1	   in	  1950	   to	  3.6	   in	  2010	   (r2=	  0.53;	  F(1,	  60)=	  65.7;	   p<	   0.001).	   Conversely,	   the	  mean	   TL	   of	   the	   offshore	   catch	   has	   increased	   slightly	  over	  the	  last	  sixty	  years.	  However,	  this	  change	  was	  not	  statistically	  significant	  (r2=	  0.05;	  F(1,	   60)=	   3.4;	   p=	   0.67).	   As	   depicted	   in	   Figure	   2-­‐1,	   the	   fish	   species	   that	   nowadays	  contribute	  most	   to	   the	   finfish	   catch	   were	   all	   being	   exploited	   in	   the	   1950s;	   it	   is	   their	  relative	  proportions	  that	  have	  changed.	  This	  transition	  thus	  represents	  a	  strong	  case	  of	  fishing	  down	  marine	  food	  webs,	  and	  not	  of	   ‘fishing	  through	  marine	  food	  webs’,	  which	  pertain	  to	  cases	  where	  low	  trophic	   level	  taxa	  are	  added	  to	  the	  exploited	  max,	  without	  the	  high-­‐trophic	  level	  species	  being	  depleted	  (Essington	  et	  al.	  2006).	  	  Given	  the	  rate	  of	  the	  decline	  in	  mean	  TL	  (0.12	  decade-­‐1),	  the	  degree	  of	  fishing	  down	  observed	  in	  the	  in-­‐shore	  Galápagos	  finfish	  fishery	  is	  consistent	  with	  global	  trends	  (Pauly	  et	  al.	  1998).	  CONCLUSIONS	  As	  of	  2006,	  57	  marine	  species	  (including	  17	  sharks)	  from	  the	  Galápagos	  were	  on	  the	  IUCN	  Red	  List,	  and	  the	  principal	  threat	  to	  32%	  of	  marine	  species	  ranked	  ‘Vulnerable’	  or	   higher	   was	   fisheries	   related	   (Banks,	   2007).	   Since	   many	   of	   the	   serranids	   described	  here	   are	   endemic	   to	   the	   Galápagos,	   they	   are	   very	   susceptible	   to	   extinction,	   and	  therefore	   require	   immediate	  conservation	  attention.	  The	   removal	  of	  predators	  can	  be	  detrimental	   to	   the	  ecosystem	  as	  a	  whole,	  and	  Ruttenberg	   (2001)	   suggests	   that	   fishing	  	   44	  for	  M.	  olfax	  not	  only	  directly	   impacts	   the	  size	  and	  health	  of	   targeted	  populations,	  but	  also	  triggers	  cascading	  effects,	  resulting	  in	  decreased	  natural	  diversity	  in	  community	  fish	  structure	   in	   areas	   experiencing	   high	   levels	   of	   fishing.	   Banks	   et	   al.	   (2012)	   have	  demonstrated	  that	  at	  locations	  where	  fishing	  is	  prohibited	  in	  the	  GMR,	  there	  is	  a	  higher	  biomass	   of	   top	   predators	   (including	   M.	   olfax).	   As	   such,	   a	   potential	   remedy	   against	  ‘fishing	   down’	   could	   be	   the	   insertion	   of	   ‘nursery	   zones’,	   as	   well	   as	   the	   addition	   and	  strengthening	  of	  restricted	  zones	  within	  the	  GMR	  (Edgar	  et	  al.,	  2008,	  Banks	  et	  al.,	  2012).	  These	  measures	   should	  enable	   fished-­‐down	  populations	   to	   rebuild,	   allow	  high-­‐trophic	  level	   species	   to	   regain	   their	   ascendancy,	   and	   provide	   spillover	   into	   the	   surrounding	  marine	  environment.	  Based	   on	   the	   past	   history	   of	   sea	   cucumber	   fishing	   in	   the	   Galápagos	   and	   the	  current	   state	   of	   the	   in-­‐shore	   finfish	   fishery	   in	   this	   region,	   if	   additional	   invertebrate	  fisheries	  for	  other	  sea	  cucumbers	  and	  urchins	  were	  initiated	  here,	  it	  is	  likely	  that	  these	  species	  would	   face	  a	  similar	  overexploitation.	  As	  discussed	  above,	   trophic	   interactions	  between	   the	   fish	   and	   invertebrate	   species	   in	   the	   Galápagos	   appear	   to	   be	   fragile	   and	  highly	   susceptible	   to	   the	   impacts	   of	   fishing.	   Although	   an	   ecosystem-­‐based,	   co-­‐management	  approach	  (including	  the	  adoption	  of	  marine	  zoning),	  was	  implemented	  in	  the	  GMR	  at	  the	  end	  of	  the	  1990s,	   the	  proposed	  management	  objectives	   faced	  several	  institutional	   challenges	   and	   were	   not	   fully	   accomplished	   in	   practice	   (Castrejón	   and	  Charles,	   2013).	   In	   this	   context,	   the	   inclusion	   of	   an	   adaptive	   fisheries	   management	  component	   to	   provide	   feeback	   from	   monitoring	   to	   account	   for	   uncertainties	   and	  shortcomings	  could	  help	  improve	  the	  ecosystem-­‐based	  approach	  in	  the	  long	  term.	  Since	  	   45	  the	  socioeconomic	  state	  of	  the	  Islands	  directly	  impacts	  the	  marine	  environment,	  Villalta-­‐Gómez	  (2013)	  also	  suggests	  an	  integration	  of	  marine	  and	  terrestrial	  management	  plans.	  Such	   merging	   would	   not	   only	   improve	   current	   conservation	   initiatives	   and	   scientific	  monitoring,	   but	   also	   allow	   for	   new	   challenges	   (e.g.	   impacts	   of	   climate	   change)	   to	   be	  addressed	  in	  a	  more	  unified	  manner.	  	  In	  2002,	  the	  whale	  shark	  (Rhincodon	  typus)	  was	   listed	  under	  Appendix	   II	  of	   the	  Convention	  on	  International	  Trade	  in	  Endangered	  Species	  (CITES,	  2002),	  and	  the	  recent	  inclusion	   of	   three	   hammerhead	   species	   (i.e.	   scalloped,	   Sphyrna	   lewini;	   smooth,	   S.	  zygaena;	   and	   great	   hammerhead	   shark,	   S.	   mokarran)	   and	   the	   oceanic	   whitetip	  (Carcharhinus	   longimanus)	   on	   this	   list	   (CITES,	   2013)	   will	   hopefully	   result	   in	   increased	  export	   monitoring	   and	   thus	   a	   decreased	   incentive	   to	   catch	   and	   fin	   these	   species.	  Nonetheless,	  based	  on	  the	  current	  scope	  of	  these	  illegal	  activities,	  it	  is	  not	  unrealistic	  to	  imagine	   several	   shark	   species	   being	   locally	   extirpated	   from	   the	   Galápagos	   within	   the	  next	   few	   decades.	   Despite	   the	   monetary	   cost,	   increased	   on-­‐water	   enforcement	   and	  monitoring	  within	  the	  GMR	  may	  be	  the	  most	  effective	  measure,	  as	  this	  would	  provide	  a	  visible	  deterrent	  to	  illegal	  fishing	  practices.	  	  	  	  	  	  	  	  	  	  	   46	  	  	  	  	  3 |	  LOST	  GIANTS	  OF	  THE	  PACIFIC	  	  	  “What	  makes	  the	  desert	  beautiful,”	  said	  the	  little	  prince,	  “is	  that	  somewhere	  it	  hides	  a	  well.”	  	  -­‐Antoine	  de	  Saint-­‐Exupéry,	  The	  Little	  Prince	  	  	  	   	  47	  INTRODUCTION	  Large	  pelagic	  fishes	  of	  the	  Pacific	  Ocean	  Covering	  162	  million	  km2	  and	  containing	  660	  million	  km3	  of	  seawater,	  the	  Pacific	  Ocean	  is	  the	  largest	  marine	  basin	  in	  the	  world;	   it	  occupies	  32%	  of	  Earth’s	  total	  surface	  area	  and	  roughly	  half	  of	  all	  its	  ocean	  space1.	  Although	  relatively	  low	  nutrient	  availability	  (when	   compared	   to	   coastal	   regions)	  makes	   the	   open	   ocean	   an	   undesirable	   place	   for	  most	  marine	  life,	  this	  environment	  is	  the	  optimal	  habitat	  for	  the	  world’s	  largest	  teleosts:	  the	  tunas	  and	  billfishes.	  As	  part	  of	  the	  scombrid2	  family,	  the	  tribe	  Thunnini	  includes	  fifteen	  fishes,	  which	  are	   collectively	   known	   as	   the	   ‘tunas’.	  Within	   this	   taxon,	   these	   species	   can	   be	   further	  classified	  into	  five	  genera:	  slender	  tunas	  (Allothunnus),	  frigate	  tunas	  (Auxis),	  little	  tunas	  (Euthynnus),	   skipjack	   tuna	   (Katsuwonus	   pelamis),	   and	   the	   albacores	   or	   ‘true’	   tunas	  (Thunnus)	   (Collette	   et	   al.	   2001).	  While	   all	   tunas	   spend	   at	   least	   some	  part	   of	   their	   life	  cycle	   in	   coastal	   areas,	   most	   slender,	   frigate,	   and	   little	   tunas	   primarily	   remain	   in	   this	  environment	   throughout	   their	   lives.	   However,	   although	   they	   return	   to	   continental	  shelves	  to	  breed,	  skipjack	  tuna	  and	  the	  eight	  species	  of	  Thunnus	  are	  primarily	  found	  in	  open	  waters.	  Given	  that	  their	  genus	  name	  originates	  from	  the	  Greek	  verb	  thynō,	  meaning	  ‘to	  rush’	  or	  ‘to	  dart’	  (Ellis	  2008),	  it	  is	  not	  surprising	  that	  the	  Thunnus	  species	  are	  among	  the	  fastest	  predators	  in	  the	  ocean.	  The	  Pacific	  is	  home	  to	  six	  tunas	  from	  this	  taxon:	  bigeye	  1Ocean	  volumes	  calculated	  by	  Eakins	  BW	  and	  Sharman	  GF	  (2010)	  from	  ETOPO1	  online	  database	  data:	  http://www.ngdc.noaa.gov/mgg/global/etopo1_ocean_volumes.html	  [accessed	  10	  March	  2013].	  254	  species	  of	  mackerels,	  tunas	  and	  bonitos	  (Nelson	  1994).	  48	  (T.	   obesus;	   BET),	   yellowfin	   (T.	   albacares;	   YFT),	   albacore	   (T.	   alalunga;	   ALB),	   longtail	   (T.	  tonggol;	  LTT),	  Pacific	  bluefin	  (T.	  orientalis;	  PBT),	  and	  southern	  bluefin	  (T.	  maccoyii;	  SBT)3	  (IATTC	   1980).	  With	   the	   exception	   of	   Pacific	   bluefin,	   which	   is	   found	   exclusively	   in	   the	  Pacific	  Ocean,	  different	  populations	  of	  all	  these	  tunas	  are	  distributed	  globally	  in	  tropical	  and	  temperate	  regions.	  	  The	   only	   fish	   faster	   than	   the	   tunas	   are	   the	   billfishes;	   some	   members	   of	   this	  family	   are	   believed	   to	   be	   capable	   of	   reaching	   swimming	   speeds	   upward	   of	   130	   km	   ⋅	  hour-­‐1	   (Block	   and	   Booth	   1992).	   These	   large	   teleosts	   are	   categorized	   based	   on	   the	  presence	  of	  an	  elongated	  rostrum,	  either	  flat	  or	  rounded,	  which	  is	  an	  extension	  of	  their	  upper	   jaw	   (Izumi	  1983).	  Swordfish	   (Xiphias	  gladius),	  which	  has	  a	  global	  distribution,	   is	  the	   only	   member	   in	   the	   billfish	   family	   Xiphiidae.	   Of	   the	   eleven	   species	   in	   the	   family	  Istiphoridae,	   six	   live	   in	   the	  Pacific	  Ocean:	   Indo-­‐Pacific	   sailfish	   (Istiophorus	  platypterus),	  black	   marlin	   (Istiompax	   indica),	   Indo-­‐Pacific	   blue	   marlin	   (Makaira	   mazara),	   striped	  marlin	  (Tetrapturus	  audax)4,	  and	  longbill	  spearfish	  (T.	  pfluegeri)	  (IATTC	  1980).	  	  Often	   travelling	   thousands	   of	   kilometers	   to	   find	   food	   at	   upwellings	   or	   reach	  specific	  mating	  grounds	  (Squire	  1974;	  Block	  et	  al.	  2001;	  Dagorn	  et	  al.	  2001;	  Shadwick	  et	  al.	   2013),	   tuna	   and	   billfish	   are	   the	   world’s	   endurance	   specialists.	   In	   the	   Pacific,	   the	  northern	   stock	   of	   albacore	   and	   Pacific	   bluefin	   undertake	   extensive	   regular	  migrations	  across	  the	  ocean	  basin,	  from	  the	  coast	  of	  Asia	  to	  North	  America	  (Allen	  2010).	  All	  bigeye	  tuna	   are	   believed	   to	   be	   part	   of	   a	   continuous	   stock	   throughout	   the	   Pacific,	   however	  3The	  other	  two	  Thunnus	  species,	  blacktail	  (T.	  atlanticus)	  and	  Atlantic	  bluefin	  (T.	  thynnus)	  are	  native	  only	  to	  the	  Atlantic	  Ocean.	  	  4Striped	  marlin	  is	  also	  known	  by	  the	  species	  name	  Kajikia	  audax.	  However,	  for	  the	  purpose	  of	  this	  work,	  it	  will	  always	  be	  referred	  to	  as	  T.	  audax.	  49	  individual	  fish	  exhibit	  less	  east	  to	  west	  movement	  compared	  to	  other	  species	  (Davies	  et	  al.	  2011;	  Aires-­‐da-­‐Silva	  and	  Maunder	  2012b).	  The	   long	  distance	  and	   fast	   swimming	   characteristic	  of	   all	   tunas	  and	  billfish	  are	  made	   possible	   by	   both	   anatomical	   and	   physiological	   adaptations,	   including	  hydrodynamic	  body	  forms,	  specialized	  fins,	  and	  ram	  ventilation	  (Brill	  and	  Bushnell	  2001;	  Graham	  and	  Dickson	  2001;	  Korsmeyer	  and	  Dewar	  2001;	  Shadwick	  et	  al.	  2013).	  Having	  evolved	  regional	  endothermic	  capabilities	  (i.e.,	  the	  ability	  to	  self-­‐regulate	  and	  heat	  their	  brain,	  muscles,	  viscera	  and	  other	  organs	  to	  a	  temperature	  above	  that	  of	  the	  surrounding	  water)	  has	  further	  enabled	  these	  pelagic	  fishes	  to	  move	  and	  hunt	  across	  both	  horizontal	  and	  vertical	   thermoclines	   and	  acquire	  adequate	   sustenance	  as	   they	   travel	   throughout	  the	  marine	  environment	   (Block	  1986;	  Brill	   1987,	  1994;	  Graham	  and	  Dickson	  2001).	  As	  such,	  tunas	  are	  opportunistic	  predators,	  capable	  of	  spending	  much	  of	  their	  adult	  lives	  in	  open	  water	  and	  the	  High	  Seas5,	  hundreds	  of	  kilometres	  from	  the	  coast	  in	  the	  epipelagic	  layer	  (i.e.,	  0-­‐200	  m	  below	  the	  surface)	  of	  the	  ocean.	  	  However,	   the	   remote	   nature	   of	   this	   environment	   is	   hardly	   a	   deterrent	   to	   the	  world’s	  commercial	  fishing	  fleets;	  tuna	  caught	  from	  the	  High	  Seas	  constitute	  to	  a	  multi-­‐billion	  dollar	  annual	  component	  of	  the	  global	  seafood	  industry.	  5The	  term	  ‘High	  Seas’	  is	  international	  territory,	  and	  denotes	  all	  bodies	  of	  water	  outside	  of	  the	  200	  nautical	  mile	  (370	  km)	  EEZs	  of	  the	  world’s	  coastal	  and	  island	  nations.	  	  	   50	  Industrial	  tuna	  fisheries	  of	  the	  Pacific	  Ocean	  	   Tuna	   fishing	   by	   pole-­‐and-­‐line	   began	   around	   the	   Pacific	   Islands	   in	   the	   1920s,	  however	   it	  was	   not	   until	   after	  World	  War	   II	   that	   industrial6	  efforts	   began	   to	   intensify	  (Gillett	   2007).	   Landings	   in	   the	   early	   1950s	   ranged	   from	   259,000-­‐348,000	   t	   per	   year;	  initially,	  smaller	  species	  (e.g.,	  skipjack	  and	  albacore)	  were	  sought	  for	  canning	  purposes	  and	   dried	   export	   by	   foreign	   (locally-­‐based)	   fleets	   from	   the	   United	   States	   and	   Japan.	  However,	  improvements	  in	  fishing	  vessel	  technology	  and	  shipping	  methods—as	  well	  as	  the	   development	   of	   flash	   freezing	   capabilities—precipitated	   a	   rapid	   expansion	   in	   the	  industry,	   in	  both	  species	  targeted	  and	  gears	  employed	  (Gillett	  2007;	  Majkowski	  2007).	  Within	   a	   relatively	   short	   period	   of	   time,	   these	   technical	   advancements	   resulted	   in	  increased	  fishing	  effort	  in	  previously	  unexploited	  off-­‐shore	  waters,	  and	  the	  subsequent	  spatial	  distribution	  of	   the	  world’s	   industrial	   fisheries—which	  primarily	   targeted	   tuna—into	  the	  High	  Seas	  (Swartz	  et	  al.	  2010a).	  	  	   Today,	  with	  annual	  landings	  exceeding	  3	  million	  t	  (i.e.,	  about	  70%	  of	  the	  current	  total	   global	   tuna	   catch)	  and	  an	  annual	   value	  of	  more	   than	  $US	  7	  billion	   (Xiaojie	   et	  al.	  2006;	  Williams	  and	  Terawasi	  2013),	   the	   tuna	   fisheries	  of	   the	  Pacific	  Ocean	  are	  among	  the	  most	  economically	   important	   seafood	  providers	   in	   the	  world.	   The	  main	   targets	  of	  these	  fisheries	  are	   four	  species	  of	   tuna:	  skipjack,	  yellowfin,	  bigeye,	  and	  albacore;	  note	  that	   only	   two	   species—yellowfin	   and	   skipjack—contribute	   86%	  of	   the	   target	   catch	   by	  weight	   (Williams	   and	   Terawasi	   2011).	   However,	   at	   the	   individual	   level,	   the	   most	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  6There	   is	  no	  universal	  definition	  of	   ‘industrial	   fishing’.	  However,	  here	   it	   is	  defined	  as	  commercial	   fishing	  activity	   off-­‐shore	   with	   large	   engine-­‐powered	   vessels	   (>	   15	   m	   in	   length).	   This	   type	   of	   fishing	   typically	  includes	  the	  use	  of	  extensive	  technological	  assistance	  (e.g.,	  satellite-­‐based	  navigation,	  sonar,	  hydraulics,	  automatic	  rail	  rollers,	  etc.)	  to	  locate	  and/or	  catch	  the	  targeted	  fish.	  	  51	  valuable	  species	  caught	  in	  the	  Pacific	  are	  bigeye	  and	  bluefin	  (Majkowski	  2007;	  Williams	  and	  Terawasi	  2011).	  	  i. Western	  Pacific	  Ocean	  (WPO)Locally-­‐based	  and	  foreign	  vessels	  operate	  in	  the	  WPO	  High	  Seas	  and	  within	  theEEZs	  of	  Pacific	  Island	  countries	  and	  territories,	  with	  the	  latter	  contributing	  about	  48%	  of	  the	  total	  regional	  catch	  (Lehodey	  et	  al.	  2011).	  Presently,	  target	  tuna	  landings	  in	  the	  WPO	  amount	   to	   about	   2.5	   million	   t	   annually,	   and	   the	   majority	   of	   this	   catch	   is	   acquired	  through	  the	  use	  of	  surface	  gears	  targeting	  yellowfin	  and	  skipjack	  for	  canning	  (Lehodey	  et	   al.	   2011;	   Sumaila	   et	   al.	   2014).	   Specifically,	   purse	   seiners	   are	   responsible	   for	   three	  quarters	  of	  the	  tuna	  caught	  in	  the	  WPO,	  whereas	  landings	  by	  pole-­‐and-­‐line	  vessels	  only	  constitute	  7%	  (Harley	  et	  al.	  2011).	  	  Historically,	  distant-­‐water	  fleets	  (DWFs)	  from	  Japan,	  Korea,	  Taiwan	  and	  the	  USA	  were	  the	  main	  purse	  seining	  operations	  in	  the	  WPO,	  with	  DWFs	  from	  China,	  Ecuador,	  El	  Salvador,	  New	  Zealand	  and	  Spain	  becoming	  more	  prevalent	  in	  the	  region	  since	  2000;	  a	  total	  of	  202	  foreign	  purse	  seiners	  fished	  here	  in	  2010	  (Williams	  and	  Terawasi	  2011).	  In	  addition,	   since	   the	   late	   1980s,	   Pacific	   Island-­‐based	   purse	   seine	   fleets	   have	   steadily	  increased	  in	  number,	  and	  in	  2010	  there	  were	  78	  locally-­‐based	  purse	  seine	  vessels	  in	  the	  WPO	  (Williams	  and	  Terawasi	  2011).	  	  Longlines	   are	   the	   second	  most	   common	   gear	   in	   the	  WPO	   (contributing	   about	  10%	  of	  the	  catch).	  Approximately	  3,500	  longliners	  in	  the	  WPO	  fall	  into	  one	  of	  two	  main	  fishing	  categories:	  i)	  large	  (>350	  GRT)	  DWF	  vessels	  with	  freeze	  capabilities	  that	  partake	  in	  extensive	  trips	  (i.e.,	  longer	  than	  a	  month)	  throughout	  large	  areas	  of	  the	  region;	  and	  ii)	  	   52	  small	  (<	  150	  GRT),	  domestically-­‐based	  offshore	  vessels	  that	  undertake	  shorter	  trips	  (less	  than	  one	  month)	  (Williams	  and	  Terawasi	  2011).	  Although	  differences	  in	  fishing	  area	  and	  target	  species	  exist	  on	  a	  country	  basis	  (Williams	  and	  Terawasi	  2011),	  all	   longline	  fleets	  target	  primarily	  mature	  bigeye	  and	  yellowfin	   (which	  are	   flash	   frozen,	   then	   thawed	   for	  sale	  as	  fresh	  for	  sashimi),	  as	  well	  as	  some	  albacore	  for	  canning	  (WCPFC	  2011;	  Sumaila	  et	  al.	  2014).	  	  	   The	  prevalence	  of	  pole	  and	  lining	  has	  decreased	  significantly	  over	  the	  last	  three	  decades	  (from	  approximately	  800	  vessels	  in	  the	  1970s	  to	  150	  vessels	  in	  2010),	  largely	  as	  a	   result	  of	   the	  expansion	  of	  purse	   seining	   (Williams	  and	  Terawasi	  2011).	  Nonetheless,	  this	   type	   of	   surface	   fishing	   remains	   a	   seasonal	   venture	   for	   Australia,	   Fiji,	   and	   Hawaii	  (domestic	   fleets),	   as	  well	   as	   Japan	   (both	  DWF	  and	  domestic	   fleets),	   and	   a	   year-­‐round	  fishery	  for	  domestic	  vessels	  from	  Indonesia,	  the	  Solomon	  Islands,	  and	  French	  Polynesia	  (Amoe	  2005;	  Langley	  et	  al.	  2010;	  WPRFMC	  2013).	  	  Although	  variation	  exists	  within	  these	  fleets	  (especially	  at	  the	  domestic	   level),	  skipjack	  is	  the	  primary	  species	  landed	  by	  pole-­‐and-­‐line	  vessels	  (about	  75%	  of	  the	  catch),	  followed	  by	  albacore	  (about	  15%),	  yellowfin	  (5-­‐10%),	  and	  bigeye	  (1-­‐5%)	  (WCPFC	  2011).	  	   Large-­‐mesh	  driftnets	  were	  briefly	  employed	  by	  Japanese	  and	  Taiwanese	  DWFs	  in	  the	   WPO	   during	   the	   1980s	   to	   catch	   albacore	   and	   skipjack.	   However,	   as	   a	   result	   of	  concerns	   over	   the	   bycatch	   of	   marine	  mammals	   and	   birds,	   this	   ecologically	   damaging	  practice	   was	   banned	   worldwide	   by	   the	   United	   Nations	   in	   1991	   (Bailey	   et	   al.	   1996).	  Currently,	   a	   small	   industrial	   troll	   fishery,	   composed	   primarily	   of	   American	   and	   New	  Zealand	   vessels,	   targets	   albacore	   in	   the	   coastal	  waters	   of	  New	   Zealand	   (Williams	   and	  	   53	  Terawasi	   2011).	   Although	   landings	   from	   this	   fishery	   were	   upward	   of	   8,000	   t	   in	   the	  1990s,	  present	  day	  efforts	  result	  in	  approximately	  2,500	  t	  annually	  (WCPFC	  2011).	  	   ii. Eastern	  Pacific	  Ocean	  (EPO)	  	   With	   an	   annual	   landed	   catch	   of	   approximately	   650,000	   t,	   commercial	   tuna	  fishing	  in	  the	  EPO	  is	  substantially	  less	  than	  in	  the	  WPO.	  However,	  as	  in	  the	  WPO,	  purse	  seine	  fleets	  are	  responsible	  for	  the	  majority	  of	  the	  tuna	  landed	  in	  the	  EPO,	  with	  82%	  of	  the	  catch	  (Hall	  and	  Roman	  2013).	  	  	   The	  onset	  of	   this	   dominance	  by	  purse	   seine	   vessels	   began	   in	   the	  1950s,	  when	  technological	   innovations	   in	   gear	   efficiency	   enabled	   a	   switch	   from	   pole-­‐and-­‐line	   tuna	  fishing;	  today,	  201	  purse	  seiners	  are	  actively	  fishing	  tuna	  in	  the	  EPO,	  compared	  to	  only	  three	  pole-­‐and-­‐line	  vessels	  (Hall	  and	  Roman	  2013;	  IATTC	  2013b).	  The	  majority	  of	  purse	  seine	   fishing—targeting	   yellowfin,	   skipjack,	   and	   bigeye—is	   carried	   out	   by	   fleets	   from	  Ecuador	  and	  Mexico	  (26%	  and	  22%	  respectively),	  as	  well	  as	  from	  other	  South	  American	  countries	   including	  Venezuela	   (10%),	  Panama	  (8%),	  Columbia	   (7%)	  and	  Nicaragua	  (4%)	  (IATTC	  2013b).	  Purse	  seining	  with	  the	  use	  of	  fish	  aggregating	  devices	  (FADs)	  has	  tripled	  in	   less	  than	  three	  decades	   in	  the	  EPO:	  from	  approximately	  2,000	  FAD	  sets	   in	  the	  early	  1990s,	  to	  more	  than	  6,000	  between	  2006	  and	  2009;	  95%	  of	  all	  floating	  object	  sets	  are	  now	  associated	  with	  this	  method	  (Hall	  and	  Roman	  2013;	  IATTC	  2013b).	   	   Distant-­‐water	   fleets	   from	   Japan,	   Korea,	   and	   Taiwan	   are	   the	   primary	   longlining	  countries	  in	  the	  EPO,	  and	  these	  countries	  target	  bigeye	  and	  yellowfin.	  Although	  catches	  were	  upward	  of	  ~110,000	  t	  in	  the	  early	  2000s,	  concern	  over	  stock	  health	  resulted	  in	  an	  54	  imposed	  tuna	  conservation	  resolution	  of	  20%	  reduction	  in	  effort	  by	  each	  fleet	  between	  2004	   to	   2009	   (IATTC	   2004).	   As	   a	   result,	   in	   2010,	   the	   total	   longline	   catch	  was	   52,113	  (IATTC	  2013b).	  In	  addition	  to	  tuna	  longlining,	  DWFs	  from	  Asia,	  South	  America,	  and	  Spain	  have	   targeted	   swordfish	   in	   the	   EPO	   since	   the	   1950s;	   between	   2000-­‐2010,	   the	   total	  annual	  catch	  of	  this	  species	  averaged	  13,500	  t	  (IATTC	  2013b).	  	  	  Coastal	  (i.e.,	  within	  EEZ)	  driftnetting	  for	  swordfish	  and	  thresher	  sharks	  still	  occurs	  in	  the	  east	  Pacific,	  and	  these	  operations	  are	  conducted	  by	  the	  USA	  and	  Mexico	  (Shore	  2013).	  Tuna	  ranching	  practices	  are	  additionally	  carried	  out	  in	  the	  EPO	  by	  Mexico;	  both	  yellowfin	  and	  Pacific	  bluefin	  are	  caught	  for	  this	  form	  of	  ranching	  (Sylvia	  et	  al.	  2003).	  iii. Southern	  Bluefin	  (SBT)Australia	  began	   fishing	   for	   southern	  bluefin	   in	   the	  SPO	  with	   the	  use	  of	   surfacegears	   in	   the	   early	   1950s	   and,	   in	   1965,	   Japan	  entered	   the	   fishery	  with	   a	  DWF	   longline	  fleet	   (CCSBT	   2011;	   Polacheck	   2012).	   SPO	   landings	   of	   southern	   bluefin	   peaked	   in	   the	  early	  1970s	  at	  ~19,000	  t,	  but	  as	  a	  result	  of	  stock	  decline,	  a	  quota	  system	  for	  this	  species	  was	   implemented	   in	   the	   1990s.	   Currently	   just	   under	   10,000	   t	   total	   catch	   (i.e.,	   for	   all	  three	   oceans)	   is	   allocated	   proportionally	   to	   each	   country	   fishing	   southern	   bluefin	  (Anonymous	  2012b).	  Currently,	   a	   total	   of	   nine	   countries	   (including	   the	   EU	   as	   a	   single	   entity)	   target	  southern	   bluefin;	   however,	   Japan	   and	  Australia	   are	   responsible	   for	   the	  majority	   (68%	  and	  28%,	  respectively)	  of	  southern	  bluefin	  caught	  in	  the	  SPO	  each	  year.	  Despite	  the	  use	  of	   other	   gears	   in	   the	   past,	   and	   a	   large	   surface	   gear	   component	   for	   southern	   bluefin	  ranching	   in	   the	   Indian	   Ocean,	   longlines	   are	   currently	   the	   primary	   gear	   used	   to	   fish	  	   55	  southern	  bluefin	  in	  the	  Pacific	  (CCSBT	  2011).	  	  Small-­‐scale	  tuna	  fisheries	  of	  the	  WPO	  	   For	  many	  of	   the	  world’s	  coastal	   regions,	   tuna	   fishing	  has	  a	   long	  and	  significant	  cultural	  history	  (Majkowski	  2007).	   In	  the	  Pacific,	  Japanese	  and	  North	  American7	  fishers	  began	  hunting	  Pacific	  bluefin	  over	   five	  millennia	  ago	   (Anonymous	  2013b),	   and	  people	  living	   in	   the	   Pacific	   Islands	   have	   fished	   for	   tuna	   at	   the	   subsistence	   level	   for	   centuries	  (SPC	   2013).	   Today,	   tuna	   remains	   an	   important	   cultural	   symbol	   and	   valuable	   natural	  resource	  for	  22	  Pacific	  Island	  countries	  and	  territories	  (Gillett	  2009;	  SPC	  2013).	  However,	  its	   economic	   significance	   in	   the	   global	   seafood	   market	   makes	   it	   both	   a	   benefit	   and	  burden	  to	  many	  of	  these	  small	  oceanic	  states	  (Gillett	  et	  al.	  2001;	  Lehodey	  et	  al.	  2011;	  Hanich	  and	  Ota	  2013;	  SPC	  2013;	  Sumaila	  et	  al.	  2014).	  	  	   In	   the	  1970s,	   less	  than	  100,000	  t	  was	   landed	  annually	  within	  the	  waters	  of	   the	  Pacific	  Islands.	  Today,	  over	  1.2	  million	  t	  is	  landed	  here	  each	  year	  (Gillett	  2007).	  However,	  in	  addition	  to	  the	  industrial	  fleets	  operating	  in	  the	  Pacific,	  many	  Pacific	  Islands	  countries	  employ	   artisanal8	  fishing	   methods	   (e.g.,	   trolling,	   handling,	   bonitier9	  fishing)	   to	   catch	  coastal	   tuna	   within	   national	   waters	   (Gillett	   2009;	   2011).	   While	   there	   is	   considerable	  variation	   in	   the	  quantity	  of	   tuna	   landed	  annually	  by	  each	  country	   (i.e.,	   ranging	   from	  a	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  7This	  refers	  to	  Aboriginal	  tribes	  on	  the	  coast	  of	  present-­‐day	  Canada.	  8Here	   the	  definition	   from	  FAO	   (2005)	   is	   used	   to	  define	   small-­‐scale	   ‘artisanal’	   fishing	   as	   “those	   fisheries	  that	   use	   vessels	   that	   are	   open	   or	   partially	   undecked,	   or	   vessels	   that	   use	   outboard	   engines	   or	   sails,	   or	  vessels	   that	   fish	   with	   handlines,	   rod-­‐and-­‐reel	   gear,	   harpoons	   or	   similar	   non-­‐industrial	   gear”.	   For	   the	  purpose	  of	   this	  work,	   this	   refers	   to	  near-­‐shore	  commercial	   fishing	   (i.e.,	  not	   recreational	  or	   subsistence)	  with	  the	  use	  of	  artisanal	  gears.	  In	  the	  Pacific,	  this	  typically	  pertains	  to	  (but	  does	  not	  exclusively	  refer	  to)	  tuna	  fishing	  in	  developing	  coastal	  regions	  and	  small-­‐island	  developing	  states	  (SIDS).	  9Inshore	  vessels	  (12m	  in	  length)	  targeting	  mostly	  skipjack	  with	  pole-­‐and-­‐line	  and	  trolling	  gear;	  still	  used	  in	  French	  Polynesia,	  but	  more	  common	  pre-­‐1990s	  (Misselis	  2002).	  	   56	  few	  tonnes	  to	  over	  ten-­‐thousand	  tonnes),	  Kiribati	   is	  by	  far	  the	   largest	  source	  of	  small-­‐scale	  tuna	  in	  the	  Pacific	  Islands.	  Over	  half	  of	  the	  region’s	  catch	  is	  caught	  by	  fishers	  from	  this	   Island	   nation,	   even	   though	   they	   make	   up	   only	   1%	   of	   region’s	   total	   population	  (Gillett	  2011).	  At	  the	  regional	   level,	  coastal	  (small-­‐scale	  fleet)	  commercial	  tuna	  catches	  by	  Island	  countries	  are	  estimated	  at	  less	  than	  50,000	  t	  total	  each	  year—only	  5%	  of	  the	  total	  landed	  offshore	  by	  foreign-­‐based	  vessels	  (Gillett	  2009).	  	  Bycatch	  associated	  with	  tuna	  fisheries	  	   Depending	  on	  the	  context	  or	  study,	  the	  term	  ‘bycatch’	  can	  have	  several	  different	  connotations.	   For	   the	  purpose	  of	   this	  work,	   ‘bycatch’	  was	  defined	   as	   all	   non-­‐targeted	  (i.e.,	   incidental)	   species	   associated	   with	   a	   given	   fishery.	   Depending	   on	   the	   situation,	  bycatch	  may	  be	  kept	  onboard	  or	  thrown	  back	  to	  sea.	  As	  such,	  two	  types	  of	  bycatch	  are	  discussed	   in	   this	   chapter:	   retained	   (r-­‐bycatch)	   and	   discarded	   (d-­‐bycatch).	   Although	  considerable	  recent	  effort	  has	  been	  put	  into	  studying	  the	  survival	  rate	  of	  fish	  and	  sharks	  discarded	   by	   various	   fleets,	   for	   the	   purpose	   of	   this	   study,	   all	   animals	   thrown	   back	   to	  sea—independent	   of	   whether	   they	   were	   alive	   or	   dead	   at	   the	   time	   of	   capture	   or	  release—were	   considered	   d-­‐bycatch.	   Similarly,	   all	   sharks	   that	   were	   finned	   prior	   to	  discarding	  were	  also	  considered	  d-­‐bycatch.	  	   While	  numerous	  factors	  play	  a	  role	  in	  the	  type	  of	  bycatch	  generated	  by	  a	  fishing	  vessel,	   bycatch	   is	   most	   directly	   related	   to	   the	   type	   of	   gear	   it	   uses.	   With	   regard	   to	  industrial	  tuna	  fishing,	  typically	  active	  gears	  (e.g.,	  pole-­‐and-­‐line,	  purse	  seine)	  have	  lower	  bycatch	  rates	  than	  passive	  gears	  (e.g.,	   longline	  and	  driftnet)	  (Lawson	  1997;	  Ardill	  et	  al.	  2011;	  Restrepo	  2011;	  Hall	  and	  Roman	  2013).	  This	  is	  most	  likely	  attributable	  to	  the	  fact	  57	  that	  active	   fishing	  methods	  are	  directly	  applied	   to	   tuna	   schools,	   rather	   than	  deployed	  and	   left	   in	   the	  ocean	   for	  a	  period	  of	   time	  before	   their	  multi-­‐species	  catch	   is	   collected	  (Hall	  1998).	  	  Nonetheless,	  even	  within	  gear	  types,	  there	  can	  be	  varying	  degrees	  of	  selectivity	  based	  on	  the	  primary	  targeted	  species	  (Broadhurst	  et	  al.	  2010).	  For	  purse	  seiners,	  more	  bycatch	  will	  be	  caught	  with	  the	  use	  of	  FADs,	  since	  these	  objects	  attract	  both	  targeted	  and	  non-­‐targeted	  fish	  (Bailey	  et	  al.	  1996;	  Fonteneau	  et	  al.	  2000;	  Hall	  and	  Roman	  2013).	  Similarly,	   variation	   in	   hook	   size	   and	   shape	  on	   longlines,	   and	   the	   size	   of	  mesh	  used	   in	  gillnets	  both	  naturally	  exclude	  some	  species	  while	  making	  others	  more	  prone	  to	  capture	  (Løkkeborg	   and	   Bjordal	   1992;	   Jude	   et	   al.	   2002).	   In	   addition	   to	   the	   fishing	   gear	   used,	  additional	   factors	   strongly	   influencing	   the	   amount	   and	   type	   of	   bycatch	   incurred	   by	   a	  fleet	  include	  where	  it	  fishes,	  and	  the	  size	  of	  its	  vessels.	  i. R-­‐bycatchAlthough	  not	  the	  directed	  focus	  of	  a	  fleet’s	  effort,	  many	  non-­‐target	  species	  areincidentally	  caught	  but	  retained	  due	  to	  their	  economic	  value	   (Alverson	  et	  al.	  1994).	   In	  the	   Pacific,	   many	   industrial	   vessels	   will	   land	   off-­‐shore	   fishes	   such	   as	   mahi	   mahi	  (Coryphaena	   hippurus),	  wahoo	   (Acanthocybium	   solandri),	   baraccuda	   (Sphyraena	   spp.),	  and	   numerous	   species	   of	   small	   scombrids	   (Bailey	   et	   al.	   1996;	   SPC	   2010).	   Many	  incidentally	   caught	   sailfish	   and	  marlins	   are	   also	   retained,	   again	   for	   their	   value	   in	   the	  global	  seafood	  market	  (Hall	  and	  Roman	  2013).	  While	  some	  small-­‐scale	  coastal	  tuna	  fleets	  are	  highly	  selective,	  others	  generate	  high	   levels	   of	   incidental	   catch	   (Gillett	   2011).	   However,	   nearly	   all	   of	   this	   bycatch	   is	  58	  retained	  (Kelleher	  2005;	  Ardill	  et	  al.	  2011;	  Gillett	  2011).	  Even	  the	  heads	  of	  some	  fish	  that	  have	  sustained	  body	  damage	  by	  sharks	  are	  kept;	  in	  many	  cases,	  only	  if	  fish	  are	  known	  to	  be	  poisonous	  or	  toxic	  are	  they	  entirely	  discarded	  (Hall	  and	  Roman	  2013).ii. D-­‐bycatchFish	   that	   are	   damaged10	  or	   species	   that	   cannot	   be	   sold	   in	   the	   internationalmarket	   are	   routinely	   discarded	   at	   sea	   (Bailey	   et	   al.	   1996;	   Kelleher	   2005).	   High	   seas	  DWFs,	  which	  have	  sailed	  far	  from	  their	  EEZ	  waters,	  will	  discard	  in	  order	  to	  maximize	  the	  value	  of	  their	  catch	  within	  the	  limited	  hold	  space	  available	  in	  their	  vessels	  (Bailey	  et	  al.	  1996).	   Similarly,	   smaller	   vessels	   fishing	  within	   territorial	  waters	  may	   also	   be	   prone	   to	  discarding	   if	   they	  fish	  exclusively	   for	  the	  fresh	  seafood	  market	  and	  do	  not	  have	  freeze	  capabilities	  onboard	  (Hall	  and	  Roman	  2013).	  As	   is	  the	  case	  with	  r-­‐bycatch,	  the	  d-­‐bycatch	  is	  highly	  variable	  depending	  on	  the	  fleet:	   discarding	   by	   industrial	   pole-­‐and-­‐line	   vessels	   is	   minimal	   (i.e.,	   <1%	   of	   the	   total	  catch),	  these	  operations	  are	  most	   likely	  to	  discard	  small	  quantities	  of	  forage	  fish	  (used	  for	   bait)11,	   and	   non-­‐tuna	   small	   pelagics	   such	   as	   rainbow	   runner	   (Elagatis	   bipinnulata)	  (Kelleher	  2005).	  Conversely,	  DWF	   longliners	   typically	  have	  very	  high	  discard	  rates	   (i.e.,	  upward	  of	  30-­‐40%	  of	  the	  total	  catch)	  and	  pelagic	  sharks	  constitute	  the	  majority	  of	  this	  unwanted	  catch	  (Kelleher	  2005;	  Xiaojie	  et	  al.	  2006;	  Huang	  2009;	  SPC	  2010).	  	  	  10Damage	   can	   be	   a	   result	   of	   either	   human	   error	   or	   natural	   predation.	   In	   the	   Australia	   longline	   fishery,	  about	  20%	  of	  the	  target	  catch	  is	  lost	  due	  to	  shark	  damage.	  11This	  study	  focused	  on	  the	  bycatch	  and	  discards	  associated	  directly	  with	  pole-­‐and-­‐line	  vessels	  and	  did	  not	  reconstruct	  any	  bycatch	  or	  discards	  associated	  with	  the	  separate	  pole-­‐and-­‐line	  baitboat	  fishery.	  Estimates	  from	  the	  Indian	  Ocean	  suggest	  that	  fish	  caught	  for	  use	  as	  bait	  by	  pole-­‐and-­‐line	  fisheries	  amounts	  to	  about	  12%	  of	  the	  target	  tuna	  catch	  (Ardill	  et	  al.	  2011).	  	   59	  iii. Discarded	  target	  species	  (D-­‐target)	   	  	   In	  addition	  to	  discarding	  incidentally	  caught	  species,	  dumping	  some	  target	  catch	  is	   also	   common	   practice	   in	   industrial	   tuna	   fleets	   (Bailey	   et	   al.	   1996;	   Kelleher	   2005).	  While	  d-­‐target	  is	  generally	  lower	  than	  d-­‐bycatch,	  this	  practice	  also	  goes	  largely	  under-­‐	  or	  mis-­‐reported,	   and	   has	   been	   a	   primary	   focus	   of	   observer	   programs	   initiated	   in	   recent	  years	  (Bailey	  et	  al.	  1996;	  Lawson	  2001;	  Román-­‐Verdesoto	  and	  Orozco-­‐Zöller	  2005;	  SPC	  2010).	  	   In	  today’s	  purse	  seine	  fisheries,	  the	  primary	  reasons	  for	  discarding	  target	  species	  are	  insufficient	  well	  holding	  space	  and	  gear	  or	  landing	  damage12	  (Hall	  and	  Roman	  2013;	  WCPFC	  2013c).	  In	  addition,	  purse	  seining	  with	  the	  use	  of	  FADs	  attracts	  both	  adult	  target	  yellowfin	   and	   skipjack	   tunas,	   but	   also	   large	  numbers	   of	   juvenile	   tunas	   (including	  non-­‐target	   bigeye),	   which	   use	   the	   structures	   for	   shelter	   and	   protection	   (Fonteneau	   et	   al.	  2000;	   Hall	   and	   Roman	   2013).	   As	   such,	   these	   small	   fish	   are	   often	   caught,	   but	  subsequently	  discarded	   (Coan	  et	  al.	  1999;	  Hall	  and	  Roman	  2013);	  a	  practice	  known	  as	  ‘high	  grading’.	  High	  grading	  occurs	  when	  smaller	  or	  damaged	  target	  fish	  are	  discarded	  in	  favour	   of	   preserving	   space	   on	   a	   vessel	   for	   a	   more	   valuable	   catch	   (i.e.,	   larger	   and/or	  undamaged	  individuals)	  (Bailey	  et	  al.	  1996;	  Cochrane	  2002).	  	  	   Damaged	   target	   fish	   (i.e.,	   self-­‐inflicted	   injuries	   while	   trying	   to	   escape,	   or	  individuals	   that	   have	   been	   predated	   upon	   by	   sharks)	   are	   common	   to	   gears	   such	   as	  longlines	  and	  driftnets,	  and	  these	  fish	  are	  also	  typically	  discarded	  (Bailey	  et	  al.	  1996).	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  12Typically	  this	  would	  include	  being	  squished	  under	  a	  purse	  seine	  beam,	  or	  mangled	  from	  getting	  snared	  in	  the	  mesh	  of	  the	  net.	  	  60	  Stock	  management	  and	  monitoring	  Given	   the	   highly	   transient	   and	   off-­‐shore	   nature	   of	   pelagic	   fishes,	   it	   would	   be	  nearly	  impossible	  to	  manage	  stocks	  on	  a	  domestic	  basis	  in	  the	  same	  way	  coastal	  species	  are	   managed.	   Thus,	   in	   1982,	   the	   United	   Nations	   devised	   the	   ‘Agreement	   for	   the	  Implementation	  of	  the	  Provisions	  of	  the	  United	  Nations	  Convention	  on	  the	  Law	  of	  the	  Sea	   (UNCLOS)	  of	  10	  December	  1982	  relating	   to	   the	  Conservation	  and	  Management	  of	  Straddling	  Fish	  Stocks	  and	  Highly	  Migratory	  Fish	  Stocks’.	  This	  agreement,	  which	  promotes	   good	   order	   in	   the	   oceans	   through	   the	   effective	   management	   and	  conservation	   of	   high	   seas	   resources	   by	   establishing,	   among	   other	   things,	   detailed	  minimum	   international	   standards	   for	   the	   conservation	   and	   management	   of	  straddling	  fish	  stocks	  and	  highly	  migratory	  fish	  stocks;	  ensuring	  that	  measures	  taken	  for	   the	   conservation	   and	   management	   of	   those	   stocks	   in	   areas	   under	   national	  jurisdiction	  and	  in	  the	  adjacent	  high	  seas	  are	  compatible	  and	  coherent;	  ensuring	  that	  there	  are	  effective	  mechanisms	  for	  compliance	  and	  enforcement	  of	  those	  measures	  on	   the	   high	   seas;	   and	   recognizing	   the	   special	   requirements	   of	   developing	   States	   in	  relation	   to	   conservation	   and	   management	   as	   well	   as	   the	   development	   and	  participation	  in	  fisheries	  for	  [straddling	  fish	  stocks	  and	  highly	  migratory	  fish	  stocks]13	  was	  adopted	  in	  1995	  before	  entering	  into	  force	  six	  years	  later.	  At	  present,	  166	  parties,	  including	  163	  UN	  member	  states,	  as	  well	  as	   the	  Cook	   Islands,	  Niue,	  and	  the	  European	  Union,	   have	   ratified	   UNCLOS.	   Notably,	   the	   United	   States	   signed	   this	   convention,	  however	   they	   have	   yet	   to	   ratify	   it	   due	   to	   concerns	   over	   its	   impact	   to	   national	  sovereignty	  and	  universal	  access	  to	  seabed	  minerals	  (Malone	  1983).	  	  	  	  	  	  Additionally,	   in	   1993,	   the	   United	  Nations	   enacted	   the	   ‘Agreement	   to	   Promote	  Compliance	   with	   International	   Conservation	   and	   Management	   Measures	   by	   Fishing	  Vessels	  on	  the	  High	  Seas’,	  which	  aims	  to	   increase	  fleet	  transparency	  on	  the	  High	  Seas,	  13From	  the	  United	  Nations	  Conference	  on	  Straddling	  Fish	  Stocks	  and	  Highly	  Migratory	  Fish	  Stocks,	  Sixth	  session,	  New	  York,	  24	  July	  –	  4	  August	  1995.	  61	  particularly	  with	   regard	   to	   flag	   and	   vessel	   ownership	   (FAO	   1995).	  Combined	  with	   the	  more	  generic	  (i.e.,	  pertaining	  to	  both	  High	  Seas	  and	  coastal	  fishing	  practices)	  FAO	  Code	  of	   Conduct	   for	   Responsible	   Fisheries 14 ,	   these	   measures	   encourage	   responsible	  international	   behaviour,	   relations,	   and	   sustainable	   fishing	   on	   the	   High	   Seas	   as	   a	  collective	  entity,	  the	  marine	  resources	  in	  each	  ocean	  are	  additionally	  managed	  at	  a	  finer	  scale.	  	  Although	   they	   cover	   a	   much	   larger	   area,	   the	   world’s	   Regional	   Fisheries	  Management	   Organizations	   (RFMOs)	   fill	   a	   similar	   role	   in	   the	   High	   Seas	   as	   national	  fisheries	   management	   bodies	   do	   in	   coastal	   waters,	   and	   each	   aims	   to	   provide	  international	  governance	  for	  a	  specific	  region	  of	  the	  world’s	  oceans	  (Figure	  3-­‐1).	   	  With	  regard	   to	   fishing,	   the	   primary	   responsibilities	   of	   RFMOs	   are	   to	   acquire	   and	   assemble	  catch	  statistics	  from	  their	  members,	  perform	  stock	  assessments	  for	  species	  within	  their	  jurisdiction,	   and	   enact	   any	   conservation	   and	   management	   measures	   (e.g.,	   member	  country	  quota	  allocation)	  (Allen	  2010;	  Cullis-­‐Suzuki	  and	  Pauly	  2010).	  Three	   RFMOs	   in	   the	   Pacific	   Ocean	   manage	   tuna	   stocks:	   the	   Inter-­‐American	  Tropical	   Tuna	   Commission	   (IATTC),	   the	  Western	   and	   Central	   Pacific	   Tuna	   Commission	  (WCPFC),	  and	  the	  Commission	   for	   the	  Conservation	  of	  Southern	  Bluefin	  Tuna	   (CCSBT).	  Both	  the	  IATTC	  and	  the	  WCPFC	  are	  responsible	  for	  collecting	  data	  pertaining	  to	  multiple	  species	   with	   populations	   within	   their	   geographical	   jurisdiction,	   while	   the	   CCSBT	  exclusively	  manages	   the	   fishing	   fleets	   associated	  with	  only	   southern	  bluefin	   across	   its	  entire	  circumpolar	  range.	  As	  such,	  the	  CCSBT	  operates	  in	  the	  Indian	  and	  Atlantic	  Oceans	  14Available	  online	  from	  FAO:	  http://www.fao.org/docrep/005/v9878e/v9878e00.htm	  [accessed	  9	  September	  2013].	  62	  as	  well;	  landings	  of	  southern	  bluefin	  in	  the	  Pacific	  Ocean	  amount	  to	  roughly	  17%	  of	  the	  total	  annual	  catch	  (CCSBT	  2011).	  	  In	   addition	   to	   the	   RFMOs,	   smaller	   independent	   research	   and	   management	  bodies	  also	  exist	  in	  the	  Pacific,	  at	  both	  the	  levels	  of	  data	  collection	  and	  research	  within	  EEZs,	   and	   throughout	   the	   High	   Seas.	   Although	   each	   is	   defined	   by	   a	   different	   set	   of	  objectives	   and	   administrative	   structure,	   these	   organizations	   are	   typically	   either	   i)	  independent	   bodies	   that	   focus	   on	   fisheries	   monitoring	   and	   research	   on	   specific	  geographical	   regions	   (e.g.,	   the	  Oceanic	   Fisheries	   Programme	  of	   the	   Secretariat	   of	   the	  Pacific	   Community;	   OFP-­‐SPC);	   ii)	   international	   organizations	   that	   focus	   on	   specific	  species	   stock	   assessments	   and	   research	   (e.g.,	   the	   International	   Scientific	   Committee;	  ISC),	   or	   iii)	   associated	   divisions	   of	   national	   or	   regional	  management	   programs,	   which	  Figure	   3-­‐1.	   Boundaries	   of	   jurisdiction	   of	   the	   Regional	   Fisheries	   Management	   Organizations	   (RFMOs)	  responsible	  for	  managing	  tuna	  (Source:	  The	  Pew	  Charitable	  Trusts,	  2011).	  63	  collect	   data	   pertaining	   to	   the	   specific	   fisheries	   of	   its	   member	   countries	   (e.g.,	   Pacific	  Islands	   Forum	   Fisheries	   Agency;	   FFA,	   Western	   Pacific	   Regional	   Fishery	   Management	  Council;	  WPRFMC).	  	  	  Purpose	  of	  study	  Attention	  toward	  bycatch	  and	  discards	   is	  becoming	   increasingly	  prevalent	  both	  within	   the	   scientific	   community,	   across	   fisheries	   management	   organizations	   and	  governing	   bodies,	   and	   also	   within	   the	   general	   public.	   Although	   many	   surface	   tuna	  fishing	  gears	  are	  considered	  low-­‐impact	  or	  ‘clean’	  (Kelleher	  2005;	  Ardill	  et	  al.	  2011),	  the	  fact	  remains	  that	  tuna	  are	  the	  main	  target	  of	  the	  largest	  commercial	  fleets	  in	  the	  world,	  and	   the	   predominant	   focus	   of	   High	   Seas	   effort.	   As	   such,	   their	  magnitude	   alone	   likely	  makes	   these	   fisheries	   some	   of	   the	   largest	   producers	   of	   bycatch	   and	   discards	   in	   the	  world.	   Given	   their	   remote	   nature,	   it	   is	   often	   difficult	   to	   maintain	   adequate	   observer	  coverage	   for	  High	   Seas	   fleets,	   a	   challenge	   that	   is	   ultimately	   reflected	   in	   the	   reporting	  accuracy	  and	  consistency	  of	  both	  target	  and	  non-­‐target	  catches.	  	  Using	  observer	  data,	  and	  any	  other	  available	  information	  from	  both	  primary	  and	  grey	  literature,	  this	  study	  aims	  to	  quantify	  and	  taxonomically	  disaggregate	  the	  retained	  bycatch	   and	   discards	   (of	   both	   bycatch	   and	   target	   species)	   associated	   with	   the	  commercial	  tuna	  fisheries	  of	  the	  Pacific	  Ocean.	  	  	   64	  METHODS	  	  Baseline	  species	  catch	  data	  	   The	   target	   species	   landings	   and	  associated	   gears	   (Table	  3-­‐1)	   used	  as	   the	   catch	  baseline	  were	   obtained	   online	   from	  publically	   available	   data	   provided	   by	   the	  WCPFC,	  IATTC,	   CCSBT,	   and	   ISC.	   With	   the	   exception	   of	   southern	   bluefin	   (see	   below),	   it	   was	  assumed	  that	  all	  target	  species	  commercial	  landings	  were	  accurately	  reported	  to	  these	  organizations	  by	  each	  country;	  all	  catch	  that	  was	  explicitly	  stated	  as	   ‘recreational’	  was	  excluded	  from	  this	  analysis.	  	  Table	  3-­‐1.	  Target	  species,	  associated	  primary	  gears	  and	  sources	  of	  data	   for	   the	   fisheries	   in	   the	  Pacific	  Ocean.	  	  	  !Target'species' Gear' Baseline'data'source'Bigeye&tuna! Longline,&purse&seine& WCPFC,&IATTC&Yellowfin&tuna! Longline,&purse&seine,&pole&and&line,&handline&WCPFC,&IATTC!Albacore&tuna& Gillnet,&longline,&pole&and&line,&troll&WCPFC,&IATTC!Skipjack&tuna! Gillnet,&longline,&pole&and&line,&purse&seine&WCPFC,&IATTC!Pacific&bluefin&tuna! Longline,&purse&seine,&troll,&pole&and&line&IATTC,&ISCa&Southern&bluefin&tuna& Longline,&purse&seine,&handline,&pole&and&line&CCSBTb&Swordfish! Longline& WCPFC,&IATTC&Sharksc& Gillnet,&longline& IATTC&aCatch&data&from&ISC&were&used&as&the&targeted&landed&catch.&All&Pacific&bluefin&catches&included&in&the&IATTC&data&for&countries&other&than&those&included&in&the&ISC&time&series&(i.e.,&other&than&Japan,&Korea,&Taiwan,&USA,&Mexico)&were&assumed&to&be&rMbycatch.&&bOriginally,&southern&bluefin&catch&data&including&both&country&and&gear&were&not&available&for&the&Pacific&Ocean&alone.&Upon&written&request,&these&data&were&provided&by&the&CCSBT.&&cThe&only&catch&assumed&to&represent&targeted&shark&fishing&was&from&the&US&and&Mexico&(gillnet),&and&the&artisanal&fleets&of&Peru&and&Guatemala.&65	  Unreported	  target	  tuna	  landings	  Using	   Japanese	   market	   and	   import	   statistics,	   Polacheck	   (2012)	   recently	  estimated	  that	  a	  total	  of	  178,000	  t	  of	  southern	  bluefin	  caught	  by	  longliners	  (all	  oceans)	  was	  under-­‐reported	  between	  1985-­‐2005	  (Table	  3-­‐2);	  these	   landings	  were	  not	   included	  in	  the	  data	  provided	  by	  the	  CCSBT.	  GraphClick	  software	  was	  used	  to	  extract	  the	  annual	  percent	  overcatch	  values	   from	  Polacheck	   (2012;	  see	  Fig.	  3),	  and	  these	  data	  were	  then	  applied	   to	   the	   total	   annual	   longline	   catch	   in	   the	   Pacific	   to	   estimate	   the	   unreported	  catch.	  This	  unreported	  catch	  was	  then	  allocated	  proportionally	  by	  fleet	  and	  included	  in	  the	  baseline	  for	  future	  calculations	  of	  associated	  bycatch	  and	  discards.	  Accounting	  for	  regional	  differences	  of	  reported	  r-­‐bycatch	  Independent	  studies	  suggest	  variability	   in	  r-­‐bycatch	  rates,	  which	  typically	  range	  from	  10-­‐40%	  of	  the	  total	  catch	  for	   industrial	   longline	  fleets	  (Bailey	  et	  al.	  1996;	  Lawson	  2001;	   Huang	   2009;	   SPC	   2010),	   and	   less	   than	   5%	   for	   purse	   seiners	   (Lawson	   2001;	  Restrepo	  2011;	  Hall	  and	  Roman	  2013).	  	  Table	  3-­‐2.	  Reconstructed	  unreported	  catch	  of	   southern	  bluefin	   in	   the	  Pacific	  Ocean.	  Overcatch	  values	  were	  extracted	  from	  Polacheck	  (2012)	  using	  GraphClick.	  	  Year% Overcatch%(%)% Unreported%catch% Year% Overcatch%(%)% Unreported%catch%1986% &12% %&%%%% 1996% 138% %2,015%%1987% 0% %&%%%% 1997% 179% %2,824%%1988% 6% %67%% 1998% 211% %3,919%%1989% 0% %&%%%% 1999% 122% %2,806%%1990% 33% %720%% 2000% 105% %2,012%%1991% 65% %1,451%% 2001% 141% %3,263%%1992% 53% %1,326%% 2002% 139% %3,616%%1993% 45% %1,387%% 2003% 124% %2,872%%1994% 91% %2,032%% 2004% 98% %1,697%%1995% 149% %3,728%% 2005% 59% %865%%!66	  In	   addition	   to	   landings	   of	   target	   species,	   both	   the	   WCPFC	   and	   the	   IATTC	  databases	   also	   included	   landings	   of	   r-­‐bycatch	   for	   several	   non-­‐target	   species.	   The	  average	  r-­‐bycatch	  longline	  rates	  from	  these	  RFMOs	  were	  10%	  and	  16%	  respectively,	  and	  0.1%	  and	  3%	  for	  purse	  seine	  catches.	  The	  last	  two	  decades	  show	  these	  rates	  to	  be	  more	  consistent	  with	  the	  independent	  values,	  and	  this	  is	  likely	  attributable	  to	  both	  improved	  observer	   coverage	   (i.e.,	  more	   realistic	  estimates)	  and	   the	   impact	  of	   geographical	   fleet	  expansion	  (i.e.,	  more	  discarding).	  	  Given	  this	  information,	  it	  was	  assumed	  that	  each	  country	  accurately	  reported	  r-­‐bycatch	  to	   the	   IATTC	  and	  WCPFC.	  However,	  although	   larger	  species	   (e.g.,	   istiophorids)	  common	  to	  longline	  fisheries	  were	  found	  in	  the	  r-­‐bycatch	  of	  both	  the	  IATTC	  and	  WFPFC,	  the	  non-­‐target	  species	  reported	  by	  the	  two	  RFMOs	  differed	  for	  small	  pelagics	  and	  other	  bony	  fishes	  that	  would	  primarily	  be	  caught	  incidentally	  by	  purse	  seiners	  (Table	  3-­‐3).	  To	  	  Table	  3-­‐3.	  Non-­‐target	  species	  r-­‐bycatch	  as	  reported	  by	  the	  Pacific	  RFMOs.	  CCSBT	  does	  not	  report	  any	  r-­‐bycatch.	  	  	  !Species' WCPFC' IATTC'Blue%shark%(Prionace)glauca)%%Yes% No%Mako%sharks%(Isurus)spp.)% Yes% No%Oceanic%whitetip%shark%(Carcharhinus)longimanus)% Yes% No%Thresher%sharks%(Alopias)spp.)% Yes% No%Silky%shark%(Carcharhinus)falciformis)% Yes% No%Misc.%sharks%(Elasmobranchiii)% No% Yes%Black%skipjack%(Euthynnus)lineatus)% No% Yes%Black%marlin%(Makaira)indica)% Yes% Yes%Blue%marlin%(Makaira)nigricans)% Yes% Yes%Striped%marlin%(Tetrapturus)audax)%% Yes% Yes%IndoBPacific%sailfish%(Istiophorus)platypterus)% No% Yes%Shortbill%spearfish%(Tetrapturus)angustirostris)% No% Yes%Misc.%bonitos%(Sarda%spp.)% No% Yes%Misc.%jacks,%runners,%jack%mackerels,%and%pompanos%(Carangidae)% No% Yes%Dolphinfishes%(Coryphaenidae)% No% Yes%Misc.%billfishes%(Istiophoridae)% No% Yes%Misc.%tunas%(Thunnini)% No% Yes%Misc.%bony%fishes%(Osteichthyes)% No% Yes%67	  account	   for	   this	  difference,	   the	   r-­‐bycatch	  of	  eight	  non-­‐reported	   species	   in	   the	  WCPFC	  was	  estimated	  by	  applying	  the	  average	  annual	  gear	  and	  country	  specific	  rates	  from	  the	  EPO	  to	  catches	  in	  the	  WPO.	  Although	  purse	  seining	  with	  the	  use	  of	  FADs	  varies	  in	  each	  region	  of	  the	  Pacific	  Ocean,	  it	  was	  assumed	  that	  this	  difference	  in	  FAD	  usage	  would	  not	  significantly	  influence	  the	  species	  composition	  of	  r-­‐bycatch.	  	  While	  sharks	  were	  included	  in	  both	  databases,	  the	  IATTC	  records	  begin	  roughly	  twenty	   years	   before	   those	   of	   the	   WCPFC.	   It	   was	   assumed	   this	   difference	   in	   species	  composition	   between	   the	   databases	  was	   a	   function	   of	   reporting	   differences	   between	  the	  RFMOs,	   rather	   than	   an	   absence	  of	   r-­‐bycatch	   of	   sharks	   prior	   to	   1990	   in	   the	  WPO.	  Thus,	  for	  missing	  years,	  the	  r-­‐bycatch	  rate	  of	  ‘Elasmobranchii’	  from	  the	  EPO	  was	  applied	  to	   the	  WPO.	   In	   order	   to	   disaggregate	   the	   generic	   group	   of	   ‘Elasmobranchii’	   from	   the	  IATTC	   data,	   the	   r-­‐bycatch	   proportions	   of	   the	   five	   species	   reported	   by	   fleets	   in	   the	  WCPFC	  were	  used.	  	  	  No	  data	  pertaining	  to	  retained	  non-­‐target	  fish	  and	  shark	  species	  were	  available	  from	   the	   CCSBT	   or	   ISC.	   As	   such,	   r-­‐bycatch	   rates	   and	   the	   associated	   annual	   species	  compositions	  based	  on	  gear	  from	  the	  IATTC	  were	  applied	  to	  both	  bluefin	  fisheries.	  Discarded	  catch	  of	  industrial	  fleets	  Two	  types	  of	  discards	  were	  considered	  for	  this	  study:	  discards	  of	  target	  species	  (d-­‐target)	  and	  discarded	  bycatch	  (d-­‐bycatch).	  Most	  sources	  gave	  discard	  information	  in	  terms	  of	  either	  a	  discard	  to	  landing	  ratio	  (i.e.,	  discards	  /landings)	  or	  as	  a	  percentage	  of	  the	   total	   catch	   (i.e.,	   discards/	   (landings	   +	   discards).	   To	   ensure	   uniformity	   across	   data	  68	  sources,	  all	   information	  was	  converted	  to	  the	   latter	  before	  being	  applied	  to	  the	  target	  catch	  time	  series.	  Given	   that	   discard	   information	   was	   difficult	   to	   obtain	   from	   the	   literature,	   the	  average	  weighted	   discard	   rates	   associated	  with	   each	   gear	   from	   Kelleher	   (2005)	   were	  held	   constant	   over	   time	   for	   many	   cases	   since	   time	   series	   could	   not	   be	   obtained.	  Although	   differences	   between	   fleets	   using	   the	   same	   gear	   will	   differ	   depending	   on	  whether	  they	  are	  local	  or	  distant-­‐water	  operations,	  it	  was	  not	  possible	  to	  separate	  these	  fleets	   using	   the	  RFMO	  country	  baseline	   catches.	   Therefore,	   for	   countries	  where	  more	  than	  one	  rate	  was	  obtained	  (i.e.,	  near-­‐shore	  and	  off-­‐shore),	  the	  average	  of	  these	  rates	  was	  used.	  	  In	  addition	  to	  pelagic	  fishes	  and	  sharks,	  the	  d-­‐bycatch	  associated	  with	  industrial	  tuna	  fisheries	  often	  consists	  of	  cetaceans,	  sea	  turtles,	  and	  seabirds.	  While	  these	  species	  are	  common	  in	  the	  High	  Seas,	  and	  numerous	  fisheries-­‐specific	  case	  studies	  exist	  for	  d-­‐bycach	   of	   non-­‐fish	   species,	   this	   study	   did	   not	   quantify	   the	   d-­‐bycatch	   of	   any	   animals	  other	  than	  pelagic	  fishes	  and	  sharks.	  Estimating	  artisanal	  bycatch	  and	  discards	  Since	  the	  majority	  of	  fishing	  for	  tunas	  and	  billfishes	  is	  carried	  out	  at	  an	  industrial-­‐scale,	  it	  was	  assumed	  (unless	  otherwise	  specified)	  that	  the	  associated	  r-­‐bycatch	  applied	  to	   these	   large-­‐scale	   practices,	   rather	   than	   artisanal	   fleets.	   Gillett	   (2011)	   recently	  attempted	   to	   quantify	   the	   global	   r-­‐bycatch	   associated	  with	   small-­‐scale	   tuna	   fisheries.	  Thus,	   for	   assumed	   small-­‐scale	   commercial	   catches	   in	   Pacific	   Island	   countries,	  independent	   r-­‐bycatch	   values	   and	   species	  breakdowns	  were	   applied	  on	  a	  per-­‐country	  69	  basis	   to	  certain	  gears	   listed	   in	   the	  WCPFC	  database	   (Table	  3-­‐4).	  When	  a	  specific	  value	  was	  not	  available,	  the	  average	  of	  known	  small-­‐scale	  gears	  was	  used.	  With	  this	  in	  mind,	  for	  many	  artisanal	   fisheries,	   it	   can	  be	  difficult	   to	  make	  a	  distinction	  between	  artisanal	  fisheries	   that	   specifically	   target	   tuna	   and	   artisanal	   fisheries	  where	   tuna	   is	   a	  merely	   a	  component	   of	   whatever	   is	   opportunistically	   caught	   during	   a	   trip	   (Gillett	   2011).	   This	  study	   assumed	   that	   the	   RFMO	   baseline	   catch	   data	   applied	   to	   fisheries	   specifically	  targeting	  tuna.	  Little	   numerical	   information	   was	   available	   regarding	   small-­‐scale	   discard	   rates,	  but	   anecdotes	   suggest	   negligible	   discarding	   by	   artisanal	   fleets	   (Gillett	   2011).	   Thus,	  despite	  high	  levels	  of	  r-­‐bycatch	  in	  many	  of	  the	  Pacific	  Island	  countries,	  a	  discard	  rate	  of	  0.5%	  was	  assigned	  to	  all	  of	   the	  previously	   identified	  artisanal	   fishing	  fleets	   for	  both	  d-­‐bycatch	  and	  d-­‐target.	  Whenever	  possible,	  species	  breakdowns	  for	  both	  r-­‐	  and	  d-­‐bycatch	  were	  assigned	  on	  a	  case-­‐by-­‐case	  basis,	  using	  country-­‐specific	  information	  (see	  Table	  6).	  	  While	   both	   bycatch	   and	   discards	   associated	   with	   the	   commercial	   small-­‐scale	  Pacific	   tuna	   fleets	   were	   estimated	   in	   this	   study	   (based	   on	   the	   data	   reported	   by	   the	  RFMOs),	   no	   subsistence	   or	   recreational	   tuna	   catches	   were	   reconstructed.	   Specific	  national	   reconstructions	  of	  unreported	  tuna	  catches	   for	   these	  sectors	  can	  be	   found	   in	  Pauly	  and	  Zeller	  (in	  prep.).	  IATTC	  and	  WCPFC	  overlap	  zone	  While	   the	   majority	   of	   tuna	   caught	   in	   the	   Pacific	   Ocean	   are	   reported	   to	   one	  RFMO	  or	   the	  other	   (based	  on	   the	   region	   in	  which	   they	  were	   caught),	   there	   is	   a	   small	  area	  (150°W	  to	  130°W;	  4°S	  to	  50°S)—	  which	  encompasses	  High	  Seas	  waters	  as	  well	  as	  	  70	  Table	   3-4.	   RI bycatch	   associated	   with	   certain	   WCPFC	   Pacific	   Ocean	   smallI scale	   fleets.	   Species	   breakdowns	  were	  also	  estimated	  based	  on	  these	  sources.	  	  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!Gear%listed%in%WCPFC%database%Country%fishing%Assumed%artisanal%gear% r9bycatch%%(as% %of%total%catch)%Source%Handline/!Small,scale!hook!and!line1!USA!(Hawaii)!Indonesia!Philippines!Handline!Handline!Handline!12!50!15!Gillett!(2011)!Gillett!(2011)!Gillett!(2011)!Ringnet! Philippines! Ringnet! 25! Anonymous!(2012)!!!!!!!!!Troll!French!Polynesia!!American!Samoa!!Cook!Islands!Fiji!!Guam!!Nauru!Tuvalu!Tokelau!USA!(Hawaii)!Bonitier!fishing!(troll!and!mixed!gears)!!Troll!!!Troll!Troll!!Troll!!Troll!Troll!Troll!Troll!21!!!3!!!25!25!!42!!4!15!15!50!Gillett!(2011)!!!Average!of!known!years!in!Gillett!(2011),!WCPFM!(2011)!!!Gillett!(2011)!Gillett!(2011);!suggesting!similar!to!Cook!Islands!!Gillett!(2011);!combined!rate!of!both!commercial!and!recreational!troll!fishing!Gillett!(2011)!Tupau!(2006)!Used!same!rate!as!Tuvalu!in!Tapau!(2006)!Gillett!(2011)!!!!Other!!Japan!Kiribati!Niue!Taiwan!French!Polynesia!Indonesia!Philippines!Mixed!gears!Troll!Troll!Unknown!Bonitier!fishing!!!Mixed!gears!(~15!types)!Mixed!gears!!45!12!67!30!21!!50!18!Gillett!(2011)!Gillett!(2011)!Gillett!(2011)!Average!of!known!rates!for!all!‘Other’!gears!Gillett!(2011)!!Gillett!(2011)!Gillett!(2011);!average!of!all!artisanal!gears!in!the!Philippines!1!No!information!specifically!pertaining!to!hook!and!line!bycatch!in!the!Philippines!or!Indonesia!could!be!found.!Thus,!it!was!assumed!this!method!of!fishing!was!most!similar!to!handlining.!71	  the	   EEZ	   of	   French	   Polynesia—where	   the	   jurisdictions	   of	   the	   IATTC	   and	   WCPFC	  geographically	  overlap.	  While	  the	  IATTC	  convention	  and	  its	  associated	  boundaries	  have	  existed	  since	  1949,	  the	  boundaries	  of	  the	  WCPFC	  Convention	  were	  officially	  designated	  only	   in	   2004.	   Thus,	   reported	   landings	   from	   this	   overlap	   zone	   are	   available	   only	   from	  1995	  (see	  Table	  1	  in	  Appendix).	  	  Overall,	   landings	   from	   the	   Pacific	   Ocean	   overlap	   area	   have	   amounted	   to	  15,000-­‐20,000	   t	   annually	   (IATTC	   2012);	   i.e.,	   less	   than	   0.2%	   of	   the	   total	   catch.	   These	  landings	   pertain	   primarily	   to	   the	   distant-­‐water	   longline	   fleets	   of	   Japan,	   the	   United	  States,	   Taiwan,	   and	   Korea,	   and	   the	   purse	   seine	   fleets	   of	   Mexico,	   the	   United	   States,	  Ecuador,	   Spain,	   Korea,	   and	   El	   Salvador.	   IATTC	   vessels	   have	   conducted	   the	  majority	   of	  purse	  seining	  in	  the	  overlap	  zone,	  while	  most	  of	  the	  longline	  vessels	  are	  related	  to	  the	  WCPFC.	   To	   avoid	   double	   counting,	   Eastern	   Pacific	   USA	   purse	   seine	   catches	   were	  removed	   from	   the	   WCPFC	   baseline	   data,	   but	   no	   other	   adjustments	   regarding	   the	  overlap	  zone	  data	  were	  made.	  RESULTS	  The	  reconstructed	  catch	  of	  target	  tunas	  and	  associated	  bycaught	  and	  discarded	  pelagic	  species	  in	  the	  Pacific	  Ocean	  between	  1950	  and	  2010	  is	  107	  million	  t	  (Figure	  3-­‐2).	  This	  represents	  an	  increase	  of	  14%	  when	  compared	  to	  the	  baseline	  target	  species	  catch	  (94	   million	   t);	   fish	   previously	   unaccounted	   for	   include	   1.4	   million	   t	   of	   r-­‐bycatch,	   3.6	  million	  t	  of	  d-­‐target,	  and	  7.9	  million	  t	  of	  d-­‐bycatch.	  	  72	  Figure	  3-­‐2.	  Total	  reconstructed	  catch	  of	  tunas	  and	  associated	  bycatch	  and	  dicards	  in	  the	  Pacific	  Ocean	  from	  1950-­‐2010.	  Total	  retained	  bycatch	  equaled	  5.2	  million	  t	  (1.4	  million	  t	  from	  the	  WPO	  were	  previously	  unreported),	   and	   unreported	   discards	   equaled	   11.5	   million	   t	   (3.6	   million	   t	   d-­‐target;	   7.9	   million	   t	   d-­‐bycatch).	  Total	  retained	  bycatch	  The	  r-­‐bycatch	  of	  the	  tuna	  fleets	  of	  the	  Pacific	  Ocean	  amounted	  to	  5.2	  million	  t.	  Since	  some	  associated	  r-­‐bycatch	  species	  were	  already	  included	  in	  the	  data	  provided	  by	  the	  RFMOs,	  this	  includes	  a	  reported	  landed	  value	  of	  3.8	  million	  t	  plus	  a	  reconstructed	  r-­‐bycatch	  of	  1.4	  million	  t	  for	  species	  missing	  from	  the	  WCPFC,	  CCSBT,	  and	  ISC	  data	  (Figure	  3-­‐3).	   The	   r-­‐bycatch	   is	   composed	   primarily	   of	   bonitos	   (23%),	   black	   marlin	   (21%),	   and	  striped	  marlin	   (14%).	   Cumulatively,	   billfish	  make	   up	   45%	  of	   the	   total	   r-­‐bycatch	   in	   the	  Pacific	  Ocean.	  	  73	  Figure	  3-­‐3.	  Reconstructed	  retained	  bycatch	  of	  species	  associated	  with	  Pacific	  Ocean	  tuna	  fleets.	  Billfish	  constitute	  45%	  of	  the	  total	  r-­‐bycatch	  in	  the	  Pacific	  Ocean	  by	  weight.	  Low	  levels	  of	  bycatch	  prior	  to	  1960	  are	  attributable	   to	   the	  prominence	  of	  pole-­‐and-­‐line	   fisheries	  at	   this	   time,	  which	  generate	   little	  bycatch.	  With	  the	  onset	  of	  purse	  seining	  and	  increased	  longlining	  in	  the	  1960s,	  associated	  bycatch	  became	  more	  prevalent,	  and	  has	  increased	  ever	  since.	  Dashed	  line	  refers	  to	  total	  reported	  catch	  (of	  both	  target	  species	  and	  reported	  r-­‐bycatch).	  (For	  complete	  species	  breakdown,	  see	  Appendix	  Table	  2,	  and	  for	  breakdown	  by	  gear,	  see	  Appendix	  Table	  5).	  	  Discarded	  target	  species	  and	  discarded	  bycatch	  This	   reconstruction	   determined	   a	   total	   of	   3.4	   million	   t	   of	   unreported	   target	  species	  discards	   since	  1950	   (Figure	  3-­‐4).	  When	   compared	   to	   the	   total	   reported	   target	  catch	  over	  this	  time	  period,	  target	  discards	  amount	  to	  4%.	  	  Conversely,	  the	  reconstructed	  d-­‐bycatch	  is	  7.9	  million	  t	  (Figure	  3-­‐5),	  the	  majority	  (60%)	   of	   which	   was	   sharks,	   specifically	   blue	   shark	   (Prionace	   glauca)	   and	   silky	   shark	  (Carcharhinus	   falciformis).	   Alone,	   these	   two	   species	   make	   up	   50%	   of	   the	   total	  reconstructed	   d-­‐bycatch.	   Non-­‐shark	   d-­‐bycatch	   was	   primarily	   unknown	   marine	   fishes	  (22%),	  and	  scombrids	  (6%).	  	   74	  	  Figure	   3-­‐4.	   Species	   composition	   of	   d-­‐bycatch	   between	   1950-­‐2010.	   Sharks	   are	   the	   most	   commonly	  discarded	   species	   (60%),	   and	   blue	   shark	   alone	   makes	   up	   36%	   of	   all	   discards.	   (For	   complete	   species	  breakdown	  see	  Appendix	  Table	  3,	  and	  for	  breakdown	  by	  gear,	  see	  Appendix	  Table	  7).	  	  	  Figure	  3-­‐5.	  Discards	  of	  target	  species	  in	  the	  Pacific	  Ocean	  between	  1950-­‐2010.	  Skipjack	  has	  the	  highest	  discard	   rate	   among	   the	   tuna	   species,	   and	   due	   to	   its	   prominence	   in	   the	   purse	   seine	   catch,	   it	   also	  constitutes	  58%	  of	  the	  discarded	  target	  catch.	  Tuna	  discards	  appear	  to	  have	  decreased	  since	  2000,	  a	  trend	  possibly	   attributable	   to	   increased	  management	  measures,	   including	   improved	   observer	   coverage	   (that	  reached	  100%	  in	  2010)	  on	  industrial	  purse	  seiners	  in	  both	  the	  Eastern	  and	  Western	  Pacific.	  (For	  complete	  breakdown	  of	  ‘Others’,	  see	  Appendix	  Table	  4	  and	  for	  breakdown	  by	  gear,	  see	  Appendix	  Table	  7).	  75	  DISCUSSION	  As	  Alverson	  et	  al.	  (1994)	  point	  out,	  discarding	  unwanted	  marine	  life	  has	  occurred	  for	  at	  least	  two	  millenia:	  Again,	  the	  Kingdom	  of	  Heaven	  is	  like	  a	  dragnet	  cast	  into	  the	  sea,	  and	  gathering	  fish	  of	  every	  kind;	  and	  when	   it	  was	   filled,	   they	  drew	   it	  up	  on	   the	  beach;	  and	   they	   sat	  down	   and	   gathered	   the	   good	   fish	   into	   baskets,	   but	   the	   bad	   they	   threw	   away	  (Matthew	  13:47-­‐48).	  Nonetheless,	   with	   a	   greater	   dependency	   on	   marine	   resources	   for	   protein,	   and	   the	  present	   state	   of	   overcapacity	   of	   the	   world’s	   fishing	   fleets,	   the	   amount	   of	   fish	   being	  thrown	  back	  to	  the	  sea	  today	  is	  estimated	  at	  over	  7	  million	  t	  annually	  (Kelleher	  2005).	  For	   Pacific	  Ocean	   tuna	   fleets,	   Kelleher	   (2005)	   additionally	   calculated	   a	   discard	   rate	   of	  7.7%	   between	   1991-­‐2001.	   In	   using	   some	   of	   the	   same	   sources,	   but	   also	   several	   new	  ones,	   this	   reconstruction	   has	   elaborated	   on	   this	   estimate	   (in	   terms	   of	   species	  composition)	  and	  also	  incorporated	  information	  from	  the	  past	  decade.	  Here,	  the	  discard	  rate	   (including	   both	   d-­‐target	   and	   d-­‐bycatch)	   for	   tuna	   fleets	   in	   the	   Pacific	   Ocean	  determined	  in	  this	  study	  between	  1950-­‐2010	  is	  10.8%.	  Predatory	  fish	  larger	  than	  1.75	  m	  in	  length	  have	  decreased	  from	  5%	  to	  1%	  of	  the	  total	  population	  as	  a	  result	  of	  commercial	  fishing	  in	  the	  Pacific	  Ocean,	  and	  the	  current	  biomass	  of	  these	  species	  is	  between	  36-­‐91%	  of	  the	  predicted	  biomass	  in	  the	  absence	  of	  fishing	   (Sibert	   et	   al.	   2009).	   Polovina	   and	  Woodworth-­‐Jefcoats	   (2013)	   recently	   showed	  that	  declines	   in	  the	  abundance	  and	  size	  of	   large	  marine	  predators	   (e.g.,	   tunas,	  billfish,	  and	   sharks)	   have	   resulted	   in	   increased	   abundance	   of	   smaller	   and	   commercially	   less	  valuable	   species	   (e.g.,	   lancetfish	   and	   snake	  mackerel).	   These	   species	  now	  have	  higher	  catch	  rates	  than	  the	  target	  species,	  which	  has	  naturally	  led	  to	  higher	  discard	  rates	  in	  the	  	   76	  fishery	   as	  well15.	   Not	   only	   does	   removing	   top	   predators	   and	   prey	   species	   impact	   the	  overall	   biodiversity	   and	   community	   structure	   of	   the	   surrounding	   environment,	   it	   also	  changes	   the	   foraging	   behaviour	   of	   species	   that	   learn	   to	   take	   advantage	   of	   discards	  (Gilman	  et	  al.	  2008a).	  	  	   In	   connection	   to	   the	   reconstructed	   numerical	   estimates,	   this	   study	   highlights	  four	   main	   areas	   of	   concern	   with	   regard	   to	   bycatch	   and	   discards	   associated	   with	  commercial	   tuna	   fisheries	   in	   the	   Pacific	   Ocean:	   i)	   uncertainty	   in	   the	   degree	   of	   catch	  under-­‐reporting	   by	   tuna	   fleets;	   2)	   the	   volume	   of	   unreported	   discarded	   catch;	   3)	   the	  composition	   of	   unreported	   discarded	   catch;	   and	   4)	   the	   absence	   of	   standardization	  pertaining	  to	  management	  records	  and	  terminology.	  	  Unreported	  landings	  and	  illegal	  tuna	  fishing	  	   Although	  this	  study	  reconstructed	  r-­‐bycatch	  for	  species	  missing	  from	  the	  WCPFC	  and	  CCSBT	  databases,	  it	  is	  possible	  that	  r-­‐bycatch	  reported	  to	  all	  of	  the	  tuna	  RFMOs	  in	  the	   Pacific	   is	   also	   under-­‐reported.	   Specifically,	   certain	   large	   Asian	   fleets	   (e.g.,	   Japan,	  Taiwan,	  China,	  Korea)	  did	  not	  report	  the	  r-­‐bycatch	  of	  some	  species	  (e.g.,	  carangids,	  and	  small	   scombrids)	   to	   the	   IATTC.	   Thus,	   it	  was	   impossible	   to	   calculate	   r-­‐bycatch	  of	   these	  species	   in	   the	  WPO	  as	  well.	  Nonetheless,	   this	  method	  was	   chosen	   in	  order	   to	   remain	  conservative	   with	   r-­‐bycatch	   estimates	   and	   to	   avoid	   losing	   species	   resolution	   at	   the	  country	   level.	  Since	  r-­‐bycatch	   information	  for	  tuna	  fleets	   is	  sporadic,	   focused	  primarily	  on	  the	  most	  prominent	  fleets,	  and	  largely	  from	  the	  last	  two	  decades,	  this	  methodology	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  15Based	  on	  time	  series	  catch	  information	  from	  with	  the	  Hawaiian	  deep-­‐set	  longline	  fishery.	  77	  decision	   was	   able	   to	   ensure	   a	   time	   series	   with	   an	   observable	   trend	   for	   the	   entire	  duration	  of	  the	  study.	  	  	  Given	   the	   uncertainty	   pertaining	   to	   unreported	   target	   tuna	   landings,	   no	  estimates	   other	   than	   those	   for	   southern	   bluefin	   provided	   by	   Polacheck	   (2012)	   were	  included	  here.	  Nonetheless,	   illegal16	  fishing	   for	   tuna	   is	  known	  to	  occur	   throughout	   the	  Pacific,	   especially	   with	   longline	   vessels	   (OECD	   2004;	   Anonymous	   2012a).	   Although	  specific	   tonnages	   associated	   with	   illegal	   (and	   mis-­‐reported)	   catches	   are	   uncertain,	  Agnew	   et	   al.	   (2009)	   suggest	   that	   from	   2000-­‐2003,	   between	   2-­‐12%	   of	   the	   global	   tuna	  catch	  was	   unreported.	   Based	   on	   a	   total	   global	   tuna	   catch	   of	   4	  million	   t	   in	   2010,	   this	  would	   presently	   amount	   to	   between	   80,000-­‐480,000	   t	   of	   tuna	   annually	  missing	   from	  national	   and	   RFMO	   catch	   records;	  with	   70%	  of	   the	   global	   catch,	   this	  means	   between	  55,000-­‐335,000	   t	  of	   tuna	  are	   illegally	   caught	   in	   the	  Pacific	  every	  year.	   The	  absence	  of	  these	  data	  also	  results	  in	  an	  absence	  of	  associated	  bycatch	  and	  discard	  estimates.	  While	  monitoring	   and	   enforcement	   efforts	   are	   improving	   in	   the	   coastal	  waters	   of	   the	  WPO,	  the	   SPC	   estimates	   that	   illegal	   fishing	   occurring	   solely	   within	   the	   territorial	   waters	   of	  Pacific	  Island	  nations	  amounts	  to	  upward	  of	  $US	  1billion	  annually17.	  	  	  Although	   they	   typically	   employ	   small	   vessels,	   small-­‐scale	   commercial	   fisheries	  are	  far	  from	  insignificant—artisanal	  gears	  annually	  landed	  just	  under	  700,000	  t	  of	  tuna	  (globally)	  in	  the	  2000s,	  not	  to	  mention	  these	  fisheries	  are	  responsible	  for	  the	  majority	  of	  tuna	   caught	   in	   many	   developing	   countries,	   including	   the	   Philippines	   and	   Indonesia	  16While	  mis-­‐reporting	  catches	  on	  the	  High	  Seas	  is	  technically	  not	  illegal	  behaviour	  (since	  the	  High	  Seas	  is	  common	  property),	  catching	  fish	  from	  within	  another	  country’s	  EEZ	  without	  proper	  access	  agreements,	  or	  violating	  the	  terms	  of	  an	  existing	  access	  agreement	  does	  constitute	  illegal	  fishing.	  	  17Obtained	   from	   online	   news:	   http://www.spc.int/en/home/216-­‐about-­‐spc-­‐news/1076-­‐regional-­‐action-­‐to-­‐fight-­‐illegal-­‐tuna-­‐fishing-­‐in-­‐the-­‐pacific.html	  [accessed	  March	  6	  2014].	  78	  (Gillett	  2011).	  However,	  fisheries	  managers	  might	  fail	  to	  adequately	  record	  the	  amount	  of	  fish	  caught	  by	  small-­‐scale	  fishers	  for	  a	  number	  of	  reasons	  pertaining	  to	  the	  nature	  of	  coastal	   fisheries	   in	   developing	   nations.	   Based	   on	   interviews	   with	   fishers	   in	   the	  Philippines,	  ‘lost’	  tuna	  can	  make	  up	  over	  10%	  of	  the	  total	  small-­‐scale	  commercial	  catch	  (Momo	   Kochen 18 ,	   pers.	   comm.).	   These	   are	   fish	   that	   were	   caught	   by	   small-­‐scale	  commercial	   fishers,	   but	   never	  made	   it	   to	   the	  market	   because	   fishers	   either	   ate	   them	  during	  the	  trip,	  gave	  them	  away	  to	  people	  immediately	  upon	  landing,	  sold	  them	  on	  the	  side	  to	  people	  other	  than	  the	  vessel	  owner	  or	  middleman	  (to	  whom	  they	  sell	  the	  bulk	  of	  their	   catch),	   or	   kept	   for	   themselves	   and	   their	   family	   (Momo	   Kochen,	   pers.	   comm.).	  Catches	  associated	  with	  this	  practice	  (and	  other	  similar	  practices	  associated	  with	  small-­‐scale	  fisheries	  in	  developing	  countries)	  were	  not	  included	  in	  this	  study.	  	  Unreported	  discards	  Two	  of	  the	  main	  goals	  of	  fisheries	  stock	  assessments	  are	  to	  determine	  the	  health	  of	   a	   given	   stock	   (i.e.,	   its	   biomass	   relative	   to	   the	  biomass	   at	  MSY),	   and	   to	   identify	   the	  intensity	   at	   which	   that	   stock	   can	   be	   fished	   sustainably	   (i.e.,	   setting	   a	   total	   allowable	  catch	   (TAC)	   for	   a	   given	   year	   or	   time	   period).	   Recent	   assessments	   suggest	   that	   Pacific	  skipjack,	  albacore	  and	  yellowfin	  are	  healthy	  and	  not	  experiencing	  overfishing	  (Hoyle	  et	  al.	  2011;	  ISC	  2011;	  Langley	  et	  al.	  2011;	  Hoyle	  et	  al.	  2012);	  however,	  analyses	  of	  bigeye,	  and	  bluefin	  stocks	  suggest	  that	  these	  tunas	  are	  all	  currently	  being	  overfished	  to	  varying	  degrees	   (CCSBT	   2011;	   Davies	   et	   al.	   2011;	   ISC	   2013c).	   Along	   with	   species-­‐specific	  18Project	  Leader	  at	  ‘Fishing	  &	  Living’,	  an	  on-­‐the-­‐ground	  collaborative	  initiative	  that	  focuses	  on	  small-­‐scale	  Indonesian	  fisheries	  research	  and	  enhancements	  to	  their	  surrounding	  socioeconomic	  environment.	  	  79	  biological	  parameters,	  catch	  statistics	  are	  one	  of	  the	  most	  important	  components	  to	  be	  incorporated	   into	   these	   assessments.	   However,	   as	   a	   result	   of	   uncertainty,	   discarded	  catch	  is	  rarely	  included.	  	  In	  general,	  discards	  of	  target	  tunas	  appear	  to	  be	  in	  decline	  over	  the	  last	  decade,	  a	   trend	   possibly	   attributable	   to	   increased	   observer	   coverage	   on	   purse	   seine	   vessels.	  Additionally,	   since	  the	  total	   reconstructed	  discards	  of	   target	  species	   is	   less	   than	  4%	  of	  the	  retained	  target	  catch	  over	  the	   last	  sixty	  years,	   the	   inclusion	  of	  this	  omitted	  fishing	  mortality	  may	  not	   significantly	   alter	   the	  outcomes	  of	   these	   stock	   assessment	   reports.	  There	   is	   additional	   question	   within	   the	   scientific	   community	   about	   the	   many	  implications	  imposed	  by	  discards	  and	  Punt	  et	  al.	  (2006)	  demonstrate	  that	  the	  inclusion	  of	  discard	   information	  can	   lead	  to	  contradictory	  assessment	  results,	  depending	  on	  the	  fishery	  and	   species	   considered.	  Nonetheless,	   if	   the	  underlying	   reason	   for	  discarding	   is	  understood,	   and	   sufficient	   discard	   data	   exist,	   then	   this	   information	   should	   be	  considered.	  Additionally,	  since	  a	  significant	  component	  of	  discarded	  tuna	  are	  juveniles,	  this	  may	  have	  a	  disproportionately	  large	  ecological	  and	  economic	  impact.	  In	  discarding	  fish	   that	   have	   not	   yet	   had	   an	   opportunity	   to	   contribute	   to	   the	   breeding	   stock,	   nor	  reached	   their	   maximum	   weight,	   fleets	   are	   inducing	   both	   recruitment	   and	   growth	  overfishing,	   which	   simultaneously	   diminish	   their	   catch	   potential	   (i.e.,	   profit)	   for	   the	  future.	  	  While	  the	  very	  nature	  of	  discarding	  suggests	  the	  release	  of	  fish	  that	  are	  deemed	  worthless	  because	  of	  size	  or	  damage,	  tuna	  that	  are	  discarded	  due	  to	  lack	  of	  vessel	  hold	  capacity	  (i.e.,	  high	  grading)	  would	  have	  some	  commercial	  value.	  This	  reconstruction	  did	  80	  not	   attempt	   to	   estimate	   the	  potential	  market	   value	  of	   the	  discarded	   catch	   (given	   the	  uncertainty	   surrounding	   the	   quality	   of	   fish	   and	   fleet-­‐specific	   rationales	   of	   discarding).	  However,	   it	   is	   important	   to	   point	   out	   that	   the	   current	  market	   prices	   for	   skipjack	   and	  yellowfin	  range	  from	  US$	  2000-­‐2,900	  t-­‐1,	  (Williams	  and	  Terawasi	  2013).	  	  A	  subset	  of	  the	  purse	   seine	   fleets	   in	   the	   WPO	   between	   2010-­‐2013	   reported	   just	   over	   10,000	   t	   of	  discarded	   target	   tuna;	   the	   primary	   reason	   (82%)	   for	   these	   discards	   was	   insufficient	  space.	  Although	   this	   represents	  0.1%	  of	   the	   total	   tuna	   landed	  by	  purse	   seiners	  during	  this	   time,	   a	   simple	   calculation	   suggests	   that	   these	   fleets	   wasted	   between	   US$	   16-­‐24	  million	  worth	  of	  marketable	  fish	  as	  a	  result	  of	  an	  entirely	  avoidable	  practice.	  	  	  For	  longliners	  especially,	  bycatch	  also	  presents	  both	  economic	  losses	  and	  safety	  concerns.	   Not	   only	   are	   bycatch	   species	   typically	   less	   valuable	   to	   the	   market,	   but	   as	  Gilman	  et	  al.	  (2008a)	  discuss,	  lost	  revenue	  can	  also	  occur	  as	  a	  result	  of	  gear	  damage	  or	  loss	   (e.g.,	   engtanglements	   or	   broken	   lines)	   and	   excess	   hauling	   time	   spent	   on	   dealing	  with	   these	  entanglements	  and	   repairing	  gear.	   In	   the	  case	  of	   sharks,	   these	   species	   can	  also	  be	  dangerous	  to	  fishers	  who	  have	  to	  handle	  their	  removal	  from	  the	  line	  when	  they	  are	  still	  alive.	  	  Composition	  of	  discarded	  bycatch	  Only	  about	  6%	   (30	   species)	  of	   the	  world’s	   sharks	  are	   found	   in	   the	  open	  ocean	  (Camhi	  et	  al.	  2009),	  yet	  21	  of	  these	  species	  are	  known	  to	  interact	  with	  industrial	  fishing	  fleets	   (Dulvy	   et	   al.	   2008).	   Based	   on	   information	   available	   in	   the	   literature,	   this	  reconstruction	  estimated	   that	  between	  1950-­‐2010,	  4.7	  million	   t	  of	   the	   total	  discarded	  bycatch	   from	   Pacific	   Ocean	   tuna	   fisheries	   are	   sharks,	   of	  which	   3.4	  million	   t	  was	   blue	  81	  shark	   and	   578,000	   t	   was	   silky	   shark.	   These	   cumulative	   catches	   seem	   high.	   However,	  Worm	  et	  al.	  (2013)	  suggested	  that	  in	  2010,	  the	  global	  shark	  catch	  (including	  unreported	  landings	   and	   discards)	   was	   1.44	  million	   t.	   The	   reconstruction	   presented	   in	   this	   study	  pertains	  exclusively	  to	  Pacific	  Ocean	  tuna	  fleets,	  and	  the	  calculated	  catch	  (both	  r-­‐	  and	  d-­‐bycatch)	  for	  this	  year	  was	  only	  125,000	  t19.	  Assuming	  this	  represents	  roughly	  50%	  of	  the	  total	   shark	   bycatch	   in	   all	   the	   oceans	   (based	   on	   the	   area	   of	   the	   Pacific	   relative	   to	   all	  oceans),	  the	  global	  total	  for	  2010	  would	  be	  only	  250,000	  t—approximately	  6	  times	  less	  than	  the	  estimate	  of	  Worm	  et	  al.	  (2013).	  Since	  the	  estimate	  in	  this	  reconstruction	  only	  accounts	   for	   sharks	   caught	   in	   association	   with	   tuna	   fleets,	   it	   is	   possible	   that	   a	   huge	  amount	   of	   targeted	   illegal	   (and	   unreported)	   shark	   fishing	   is	   occurring	   and	   these	  practices	  account	  for	  this	  difference.	  It	  is	  also	  possible	  that	  the	  variation	  in	  the	  resulting	  estimates	   between	   these	   two	   studies	   is	   attributable	   to	   substantial	   differences	   in	  research	  methodology.	  	  Worm	   et	   al.	   (2013)	   calculated	   their	   value	   from	   various	   broad	   assumptions	  pertaining	  to	   illegal	   fishing	  and	  degrees	  of	  catch	  underreporting	  to	  expand	  on	  existing	  reported	   shark	   landings	   whereas	   this	   reconstruction	   used	   discard	   ratios	   from	   the	  literature	  applied	  to	  target	  industrial	  landings	  (for	  species	  other	  than	  sharks).	  Worm	  et	  al.	   (2013)	  also	  attempted	   to	   reconstruct	  artisanal	   shark	   fisheries,	  which	   this	   study	  did	  not	  do.	  With	   regard	   to	   their	  estimate	  of	   total	   longline	  catch,	  Worm	  et	  al.	   (2013)	  used	  observed	  regional	  shark	  catch-­‐per-­‐unit-­‐effort	  (CPUE)	  data	  and	  associated	  regional	  hook	  effort	   to	   calculate	   the	   shark	   discards	   associated	   with	   each	   ocean.	   However,	   upon	  19	  Since	  this	  reconstruction	  did	  not	  address	  the	  issues	  of	  mortality	  at	  capture	  or	  post-­‐discard	  mortality,	  this	  represents	  a	  cumulative	  discarded	  tonnage,	  not	  all	  of	  which	  would	  have	  been	  killed.	  	  	   82	  examination	  of	  this	  method,	  it	  appears	  that	  the	  total	  annual	  hook	  effort	  was	  cumulative	  (rather	   than	   averaged	   for	   a	   given	   time	   period).	   Additionally,	   the	   calculated	   average	  CPUE	  per	  ocean	  was	  not	  weighted	  by	  the	  scale	  of	  each	  fleet	  (i.e.,	  total	  hooks	  per	  fleet),	  nor	  target	  species,	  nor	  was	  it	  specific	  to	  commercial	  fleets	  (e.g.,	  a	  CPUE	  of	  91.1	  sharks	  ⋅	  1000	  hooks-­‐1	  from	  a	  research	  vessel	  shark	  survey	  off	  Japan	  that	  used	  only	  28,800	  hooks	  was	   made	   comparable	   to	   a	   CPUE	   of	   0.6	   sharks	   ⋅	   1000	   hooks-­‐1	   from	   the	   industrial	  Taiwanese	   tuna	   fleet	   with	   14.1	   million	   hooks).	   These	   biases	   toward	   large	   CPUE	  estimates	   associated	  with	   small	   fleets	  were	   undoubtedly	   further	   amplified	   upward	   as	  the	  scale	  of	  the	  computation	  was	  raised	  to	  1.4	  billion	  hooks	  (i.e.,	  the	  global	  estimated	  effort	  in	  2010).	  	  	   Sharks	   are	   well-­‐known	   for	   their	   ecological	   role	   as	   top	   predators	   in	   the	   open	  ocean,	  and	  research	  suggests	  significant	  cascading	  ecosystem	  effects	  as	  a	  result	  of	  their	  removal	   from	   the	   pelagic	   environment	   (Stevens	   2000;	  Myers	   et	   al.	   2007;	  Dulvy	   et	   al.	  2008;	  Ferretti	  et	  al.	  2010).	  The	  life	  history	  characteristics—specifically	  growth	  rate	  and	  fecundity—of	   each	   species	   differ	   widely	   (Cortés	   2005);	   thus	   the	   observed	   impact	   of	  their	   removal	   (as	  well	  as	   their	   resilience	  to	   fishing	  pressure)	  will	  also	  be	  highly	  varied.	  However,	  in	  general,	  shark	  populations	  decline	  faster	  and	  rebound	  slower	  than	  teleosts	  under	  the	  same	  fishing	  pressure	  (Musick	  2005a).	   In	  addition	  to	  typically	  K-­‐selected	  life	  histories	  and	  low-­‐abundance	  when	  compared	  to	  most	  tunas,	  Cailliet	  et	  al.	  (2005)	  explain	  that	   the	  nature	  of	  many	   sharks	   to	   congregate	  at	   certain	   age	   classes,	   or	  by	   sex,	  might	  make	  them	  further	  susceptible	  to	  overfishing	  and	  recovering	  from	  declines	  in	  stock	  size.	  Different	  estimates	  of	  population	  decline	  have	  been	  suggested	   in	  the	   last	  decade,	  and	  	   83	  32%	  of	  pelagic	  sharks	  and	  rays	  are	  considered	  ‘Threatened’	  with	  regard	  to	  IUCN	  criteria	  (Camhi	   et	   al.	   2009).	   However,	   only	   recently	   has	   an	   effort	   to	   undertake	   stock	  assessments	  on	  Pacific	  Ocean	  sharks	  become	  a	  focus.	  	  	   Since	   sharks	   are	   not	   targeted	   species,	   researchers	   in	   charge	   of	   these	  assessments	   also	   face	   the	   challenge	   of	   estimating	   bycatch	   and	   (dead)	   discards.	  Nonetheless,	   using	   a	   surplus-­‐production	  model	   in	   combination	  with	   information	   from	  the	  literature	  to	  reconstruct	  a	  catch	  time	  series	  from	  1971-­‐2011,	  the	  2013	  assessment	  of	  the	  North	  Pacific	  stock	  of	  blue	  shark	  suggests	  it	  is	  not	  currently	  being	  overfished	  (ISC	  2013a)20.	  Conversely,	  the	  2012	  stock	  assessment	  for	  silky	  shark	  found	  that	  overfishing	  is	  occurring	   within	   the	   waters	   of	   the	   WPO	   (Rice	   and	   Harley	   2012).	   Although,	   this	  reconstruction	  shows	  that	  the	  catch	  of	  blue	  shark	  is	  much	  higher	  than	  that	  of	  silky	  shark,	  it	   is	   important	   to	   note	   that	   different	   sharks	   also	   incur	   different	   levels	   of	   mortality	  associated	  with	  discarding,	  and	  studies	  show	  tuna	  longline	  fleets	  with	  upward	  of	  94%	  of	  sharks	   still	   alive	  by	   the	   time	   they	  are	   retrieved	   (Gilman	   et	  al.	  2008a).	  Although	   in	   this	  study,	  discards	  were	  not	  further	  divided	  into	  dead	  and	  survived	  categories,	  Beerkircher	  et	   al.	   (2002)	   show	   that	   blue	   sharks	   are	   actually	   much	   less	   likely	   to	   be	   dead	   upon	  retrieval	  than	  are	  silky	  sharks	  in	  some	  longline	  fisheries	  (12.2%	  mortality	  in	  blue	  sharks	  compared	   to	   66.3%	   in	   silky).	   Other	   research	   suggests	   the	   capture	   mortality	   of	   blue	  sharks	  in	  industrial	  fisheries	  may	  actually	  range	  from	  5-­‐35%	  and	  post-­‐release	  mortality	  is	  an	  additional	  19%	  (Campana	  et	  al.	  2009).	  Nonetheless,	  this	  ability	  to	  survive	  incidental	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  20Comparison	   between	   the	   catch	   data	   used	   for	   this	   population	   assessment	   and	   the	   data	   in	   this	  reconstruction	  was	  not	  possible	  since	  the	  reconstructed	  values	  apply	  to	  the	  total	  Pacific	  Ocean	  blue	  shark	  catch	  (i.e.,	  North	  and	  South	  stocks).	  	  	   84	  capture,	  combined	  with	  the	  resilient	  life	  history	  of	  the	  blue	  shark,	  may	  contribute	  to	  its	  ability	  to	  withstand	  such	  high	  levels	  of	  catch.	  	  	   In	   addition	   to	   interactions	   with	   longline	   fleets,	   silky	   sharks	   are	   the	   most	  commonly	   bycaught	   shark	   by	   purse	   seiners	   in	   the	   Pacific	   (IATTC	   2009).	   As	   a	   result	   of	  concerns	   over	   silky	   shark	   populations,	   both	   the	   IATTC	   and	   WCPFC	   have	   recently	  implemented	   conservation	   measures	   protecting	   this	   shark	   in	   the	   Pacific.	   These	  measures	   prohibit	   targeted	   capture	   of	   this	   species,	   as	   well	   as	   the	   retention	   of	   any	  incidentally	  caught	  individuals	  (IATTC	  2013a;	  WCPFC	  2013a).	  Since	  the	  majority	  of	  silky	  shark	   bycatch	   occurs	   in	   the	   northern	   part	   of	   the	   EPO,	   the	   IATTC	   has	   additionally	  discussed	   time-­‐area	   closure	   measures	   in	   this	   region	   (IATTC	   2009).	   However,	   the	  implementation	  of	  any	  temporal	  or	  spatial	  restrictions	  has	  yet	  to	  occur.	  	  	   Due	   to	   its	   high	   concentration	   of	   urea,	   shark	   meat	   typically	   has	   very	   little	  commercial	  value,	  which	  is	  why	  these	  animals	  are	  so	  commonly	  discarded	  dead	  at	  sea	  (Musick	   2005b).	   Conversely,	   shark	   fins21	  are	   worth	   upward	   of	   US$	   400	   ⋅	   kg-­‐1,	   and	  Chinese	   demand	   for	   their	   cartilage	   has	   resulted	   in	   widespread	   illegal	   shark	   finning	  operations	  (Jacquet	  et	  al.	  2008).	  This	  practice	  is	  undoubtedly	  putting	  additional	  pressure	  on	  shark	  populations,	  and	  many	  industrial	   longline	  fleets	  are	  now	  specifically	  targeting	  sharks	   instead	  of	   tuna	   (Gilman	  et	  al.	  2008a).	  Several	  countries	  have	  national	   laws	  and	  both	  the	  WCPFC	  and	   IATTC	  have	  Conservation	  and	  Management	  Measures	  (CMMs)	  to	  prohibit	  or	  limit	  shark	  finning	  (Biery	  and	  Pauly	  2012;	  Gilman	  et	  al.	  2012).	  These	  efforts	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  21A	   standard	   ratio	   of	   5%	   for	   fin	   to	   total	   body	   weight	   is	   commonly	   used	   in	   legislative	   documents	   and	  regulations.	  However,	   in	   reality,	   this	   ratio	  varies	  substantially	  by	  species:	   the	   fin	   to	  body	  weight	   ratio	   is	  2.06	  for	  the	  common	  thresher	  shark,	  5.65	  for	  blue	  shark,	  4.46	  for	  the	  silky	  shark,	  and	  7.34	  for	  the	  oceanic	  whitetip	  shark	  (Biery	  and	  Pauly	  2012).	  	   85	  have	   resulted	   in	   decreased	   shark	  mortality	   in	  many	   fisheries,	   since	   there	   is	   increased	  economic	   incentive	   to	  avoid	  shark	  bycatch	  altogether	   (Gilman	   et	  al.	  2008a).	  However,	  since	  not	  all	  waters	  have	  shark	  fishing	  regulations,	  finning	  operations	  are	  still	  pervasive	  in	   the	   Pacific	   Ocean,	   especially	   in	   South	   American	   countries	   (NOAA	   2013),	   and	   the	  effectiveness	  of	  RFMO	   legislation	  regarding	   this	  practice	   is	  questionable	   (Gilman	  et	  al.	  2012).	  Impacts	  of	  tuna	  fisheries	  on	  air-­‐breathing	  marine	  animals	  	   While	   this	   study	   did	   not	   analyse	   the	   impacts	   of	   tuna	   fisheries	   on	   marine	  mammals,	  sea	  birds,	  or	  sea	  turtles,	   it	   is	   important	  to	  mention	  that	  these	  air-­‐breathing	  marine	  megafauna	  can	  also	  be	  significant	  components	  of	  tuna	  fleet	  bycatch.	  Similar	  to	  some	   sharks,	   these	   animals	   are	   particularly	   vulnerable	   to	   unnatural	   mortality	   due	   to	  characteristics	   of	   their	   life	   histories	   (i.e.,	   long	   lifespan,	   delayed	   age	   of	   maturity,	   low	  reproductive	   rates)	   (Gilman	   et	   al.	   2008a).	   Since	   they	   have	   no	   commercial	   value,	   and	  typically	  drown	  before	  they	  can	  be	  released	  from	  gear	  or	  sustain	  life-­‐threatening	  injuries	  as	   a	   result	   of	   entanglement,	   the	  mortality	   associated	  with	  bycatch	  of	   these	   species	   is	  high	  (Lewison	  et	  al.	  2004a;	  Larese	  and	  Coan	  2008;	  NMFS	  2011).	  Bycatch	  of	  air-­‐breathing	  marine	   megafauna	   is	   especially	   concerning,	   given	   high	   levels	   of	   vulnerability	   and	  ‘Endangered’	  status	  associated	  with	  many	  families	  of	  marine	  birds	  and	  sea	  turtles	  (Gales	  et	  al.	  1998;	  Lewison	  et	  al.	  2004b).	  	   The	  most	   recent	   global22	  study	   of	   bycatch	   on	   air-­‐breathing	  marine	  megafauna	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  22Meta-­‐analysis	  that	  assessed	  the	  impacts	  of	  both	  industrial	  and	  small-­‐scale	  coastal	  fishing	  (not	  only	  tuna)	  with	  driftnets,	  longlines,	  and	  trawls.	  86	  showed	  a	  high	  prevalence	  of	  both	  marine	  mammal	  and	  sea	   turtle	  bycatch	   intensity	   in	  the	  Eastern	  Pacific,	  compared	  to	  other	  ocean	  regions	  (Lewison	  et	  al.	  2014).	  This	  meta-­‐analysis	   also	   showed	   that	   while	   the	   impacts	   of	   driftnets	   appear	   to	   be	   uniform	  throughout	  the	  world,	  bycatch	  intensity	  and	  composition	  associated	  with	  both	  longline	  and	  trawl	  gear	  does	  vary	  by	  region.	  This	  is	  attributable	  to	  both	  the	  gear	  required	  to	  land	  the	   target	   species,	   as	   well	   as	   the	   abundance	   of	   non-­‐target	   marine	   life	   in	   the	   area.	  Crowder	   and	   Myers	   (2001)	   found	   that	   Atlantic	   high	   seas	   longline	   fleets	   targeting	  swordfish	   are	  10	   times	  more	   likely	   to	   catch	   loggerhead	   sea	   turtles	   than	   tuna	   longline	  fleets,	   and	   Gales	   et	   al.	   (1998)	   showed	   that	   Japanese	   tuna	   longline	   fleets	   operating	  around	  Australia,	   are	   responsible	   for	   high	  mortalities	   of	   albatross	   and	  other	   seabirds.	  Similar	   to	   bycatch	   and	   discard	   issues	   associated	   with	   sharks	   and	   other	   fish,	   notable	  concerns	   with	   regard	   to	   understanding	   the	   impact	   of	   fisheries	   on	   air-­‐breathing	  megafauna	   are	   incomplete	   data	   sets,	   a	   lack	   of	   observer	   coverage,	   and	   inadequate	  bycatch	  reporting	  by	  fleets	  (Lewison	  et	  al.	  2004a).	  Bycatch	  mitigation	  efforts	  If	   on-­‐board	   vessel	   mentality	   and	   behaviour	   pertaining	   to	   discarding	   does	   not	  change,	  then	  one	  way	  to	  decrease	  the	  amount	  of	  sharks	  (and	  other	  d-­‐bycatch	  species)	  thrown	  back	  to	  sea	   is	  to	  prevent	  their	  capture	   in	  the	  first	  place.	  Attempts	  to	  minimize	  bycatch	   of	   both	   non-­‐target	   fish,	   and	   air-­‐breathing	   marine	   megafauna	   are	   becoming	  more	  prevalent	   in	   industrial	   fisheries,	  primarily	   through	   the	  modification	  of	   gears	  and	  fishing	  strategies.	  However,	  as	  Gilman	  et	  al.	  (2008a)	  point	  out,	  substantial	  progress	  has	  been	  made	  in	  reducing	  seabird	  and	  sea	  turtle	  bycatch	  in	  longline	  fisheries,	  yet	  relatively	  	   87	  little	  focus	  has	  been	  given	  to	  reducing	  marine	  mammal	  and	  shark	  interactions	  with	  this	  gear.	  Modifications	  to	  longline	  hooks	  are	  additionally	  believed	  to	  decrease	  the	  number	  of	   sea	   turtles	   caught	   by	   these	   vessels	   (Read	   2007),	   and	   the	   use	   of	   seabird	   avoidance	  fishing	  methods	  (i.e.,	  side	  setting	  and	  weighted	  hooks)	  has	  seen	  a	  67%	  decline	  in	  seabird	  bycatch	   in	   the	   Hawaiian	   longline	   fleet	   since	   these	   regulations	   were	   implemented	  (Gilman	   et	   al.	   2008b).	   Recent	   research	   suggests	   that	   using	   circle	   hooks	   instead	   of	   J-­‐hooks	  may	  reduce	  the	  catch	  mortality	  of	  blue	  sharks	  and	  swordfish	  as	  well	   (Kerstetter	  and	  Graves	  2006;	  Carruthers	  et	  al.	  2009).	  In	  addition	  to	  gear	  type,	  blue	  shark	  survival	  is	  also	   dependent	   on	   soak	   time,	   depth	   of	   hooks,	   water	   temperature,	   and	   size	   of	   the	  individual	  (Campana	  et	  al.	  2009).	  	  	   In	   the	   Eastern	   Pacific	   Ocean,	   yellowfin	   schools	   are	   commonly	   associated	   with	  pods	  of	  dolphins,	  and	  in	  the	  early	  days	  of	  purse	  seining,	  estimates	  of	  dolphin	  mortality	  associated	  with	  this	  gear	  were	  between	  300,000-­‐600,000	  individuals	  per	  year	  (Edwards	  and	  Perkins	  1998;	  Hall	  1998).	  However,	  as	  a	  result	  of	   improved	  fishing	  technique	  (i.e.,	  decreasing	   the	   kill-­‐per-­‐set	   rather	   than	   decreasing	   the	   number	   of	   sets),	   protective	  legislation	  led	  by	  the	  United	  States,	  and	  improved	  observer	  coverage,	  dolphin	  mortality	  due	  to	  purse	  seining	  declined	  substantially	  to	  about	  25,000	  individuals	  per	  year	  in	  1991,	  and	  currently	  equates	  to	   less	  than	  1,200	  dolphins	  per	  year	  (IATTC	  2008).	  As	  such,	  EPO	  dolphin	  populations	  are	  not	  currently	  threatened	  by	  this	   incidental	  take	  (Lennert-­‐Cody	  et	  al.	  2012).	  	  	   88	  Limitations	  of	  study	  	   Given	  both	   the	   temporal	   and	   spatial	   extent	  of	   this	  work,	  numerous	   challenges	  were	   uncovered	   with	   regard	   to	   both	   the	   quantity	   and	   quality	   of	   data	   available	   (i.e.,	  origin	  and	  number	  of	  reference	  materials)	  and	  the	  accuracy	  of	  these	  sources.	  As	  such,	  several	  assumptions	  regarding	  the	  data	  had	  to	  be	  made	  throughout	  the	  duration	  of	  this	  study.	   These	   assumptions	   were	   made	   based	   on	   all	   available	   information	   within	   the	  specific	  context	  of	  this	  work	  (i.e.,	  tuna	  fisheries	  in	  the	  Pacific)	  as	  a	  whole.	  	  	   	  Even	  before	  any	  RFMO	  baseline	  data	  were	  made	  publically	  available,	  they	  first	  had	   to	   be	   collected	   (i.e.,	   through	   tuna	   fishing)	   and	   provided	   by	   the	   fleets	   of	   each	  country.	  As	  was	  discussed	  above,	  under-­‐reported	  tuna	  landings	  are	  not	  uncommon.	  The	  accuracy	  of	  vessel	  logbooks	  has	  been	  questioned	  on	  numerous	  occasions	  (Babcock	  and	  Pikitch	   2003),	   and	   studies	   have	   shown	   serious	   under-­‐reporting	   by	   industrial	   fleets,	  primarily	  with	  regard	  to	  amounts	  of	  bycatch	  and	  discards	  (Bailey	  et	  al.	  1996),	  but	  also	  in	  terms	   of	   incorrect	   species	   identification	   (Walsh	   et	   al.	   2005).	   Given	   this	   heavy	  dependency	  on	  honest	  reporting,	  not	  to	  mention	  natural	  human	  error	  in	  doing	  so,	  it	  is	  possible	   that	   the	  baseline	  data	  upon	  which	  bycatch	  and	  discards	  were	  calculated	  may	  already	  have	  been	  a	  misrepresentation	  of	  the	  total	  catch.	  	  	   Additionally,	   since	   observer	   coverage	   is	   lowest	   on	   High	   Seas	   and	   DWF	   vessels	  (<1%),	   and	   also	   varies	   significantly	   between	   fleets	   and	   countries	   (Lawson	   2001;	   SPC	  2010),	  observed	  bycatch	  and	  discard	   rates	  often	  pertain	   to	  only	  a	   small	   subsection	  of	  the	  total	  fishing	  effort	  in	  a	  given	  area	  (Bailey	  et	  al.	  1996).	  As	  has	  been	  demonstrated	  in	  several	  cases,	  seasonality	  and	  location	  often	  play	  a	  significant	  role	   in	  both	  the	  amount	  89	  and	  type	  of	  bycatch	  obtained	  by	  a	  given	  fleet	  (Bailey	  et	  al.	  1996;	  Harrington	  et	  al.	  2005;	  Román-­‐Verdesoto	   and	   Orozco-­‐Zöller	   2005).	   Nonetheless,	   given	   the	   (theoretically)	  unbiased	   nature	   of	   independent	   fisheries	   observers	   and	   notwithstanding	   human	  observation	   error,	   this	   study	   typically	   accepted	   their	   data	   as	   being	   the	  most	   reliable	  source	  of	  information.	  	  In	   terms	   of	   the	   data	   that	  were	   used,	   short-­‐term	   studies	   and	   a	   general	   lack	   of	  sequential	  time-­‐series	  forced	  the	  application	  of	  only	  one	  discard	  rate	  from	  a	  single	  year	  that	  was	  then	  held	  constant	  over	  time.	  When	  no	  discard	  rate	  was	  available	  for	  a	  given	  fleet,	  assumptions	  regarding	  their	  behaviour	  were	  inferred	  from	  the	  behaviour	  of	  similar	  fleets	  (i.e.,	  same	  gear	  or	  nationality).	  Data	  pertaining	  to	  fleet	  bycatch	  and	  discards	  were	  almost	  entirely	  non-­‐existent	  before	  the	  1980s,	  which	  ultimately	  resulted	  in	  an	  inability	  to	  capture	  a	  change	  in	  discarding	  behaviour	  over	  time	  for	  most	  fleets.	  Specifically,	  the	  application	   of	   a	   single	   rate	   masks	   any	   changes	   in	   fleet	   discarding	   practices	   due	   to	  advancements	   in	  gear	   technology	  and	  the	  pressures	  of	  vessel	   space	   limitations,	  which	  are	  heightened	  by	  fleet	  spatial	  expansion.	  	  Also	   with	   regard	   to	   data	   sources,	   a	   more	   uniform	   definition	   of	   ‘bycatch’	   and	  ‘discards’	  would	  be	  useful	   for	  future	  work	   in	  this	  area.	  Although	  they	  were	  specifically	  defined	   for	   this	   study	   (see	   page	   56),	   inconsistencies	   in	   the	   literature	   regarding	   these	  terms	  undoubtedly	  resulted	  in	   less	  efficient	   interpretation	  of	  data,	  as	  well	  as	  the	  need	  for	  additional	  assumptions	  regarding	  the	  application	  of	  some	  information.	  As	  Davies	  et	  al.	  (2009)	  discuss,	  perceptions	  of	  target	  and	  non-­‐target	  catch	  vary	  widely	  depending	  on	  the	   source	   and	   fishery,	   and	   these	   perceptions	   are	   additionally	   inconsistent	   through	  90	  time.	  Thus,	  even	   if	  a	  standardized	  form	  cannot	  be	  agreed	  upon	  (e.g.,	  discard	  rate	  as	  a	  percentage	  of	  total	  landed	  catch	  vs.	  total	  catch	  vs.	  species	  specific	  catch),	  a	  standardized	  definition	   of	   these	   two	   terms	   is	   essential	   for	   ensuring	   an	   accurate	   depiction	   and	  understanding	  of	   the	   impacts	   of	   bycatch	   and	  discards	   (for	   any	   fishery	   at	   any	   level)	   in	  future	  studies.	  Since	  tuna	  fisheries	  landings	  are	  typically	  considered	  in	  terms	  of	  tonnage,	  it	  would	  also	  be	  highly	  beneficial	  if	  the	  standard	  form	  of	  reporting	  associated	  discarded	  fish	  was	   to	   calculate	   them	   in	  weight	   rather	   than	   report	   them	   in	   terms	   of	   number	   of	  individuals.	  Lastly,	   despite	   the	  multinational	  nature	  of	  Pacific	  Ocean	   tuna	   fleets,	   this	   study	  relied	  exclusively	  on	  data	  published	  in	  English.	  As	  such,	  it	  is	  possible	  that	  more	  accurate	  and/or	  complete	  information	  or	  specific	  fleet	  data	  published	  in	  different	  languages	  were	  overlooked.	   In	   order	   to	   mitigate	   this,	   closer	   coordination	   with	   country-­‐based	  reconstruction	  authors	  for	  a	  similar	  study	  in	  the	  future	  would	  be	  useful.	  CONCLUSIONS	  The	  IATTC	  has	  had	  100%	  purse	  seine	  observer	  coverage23	  on	  large	  vessels	  (>	  363	  t) since	   the	   1990s,	   and	   at	   the	   start	   of	   2010,	   the	  WCPFC	   implemented	   100%	  observercoverage	   on	   purse	   seiners	   in	   its	   waters	   as	   well	   (IATTC	   2008;	   Hampton	   2009).	   While	  these	   efforts	   are	   highly	   encouraging,	   additional	   focus	   should	   be	   given	   to	   longliners,	  since	  these	  vessels	  have	  the	  highest	  rates	  of	  bycatch	  and	  discards	  (and	  are	  more	  prone	  to	   capturing	   sharks	   than	   are	   purse	   seiners).	  While	   there	   are	   exceptions	   as	   a	   result	   of	  23At	  least	  half	  of	  the	  observers	  on	  each	  Party’s	  vessels	  must	  be	  IATTC	  observers;	  the	  remainder	  may	  be	  from	  the	  Party’s	  national	  observer	  program.	  	   91	  national	   legislation	   (e.g.,	   100%	  observer	   coverage	   on	  Hawaii-­‐based	   longline	   swordfish	  vessels	   since	   2004),	   both	   the	   IATTC	   and	   WCPFC	   require	   only	   5%	   regional	   observer	  coverage	  for	  longline	  vessels	  under	  their	  jurisdiction	  and	  in	  the	  high	  seas	  (IATTC	  2011b;	  WCPFC	  2013b).	  Although	  this	  measure	  has	  only	  existed	  for	  a	  couple	  of	  years,	  in	  addition	  to	   the	   obvious	   issue	   of	   coverage	   inadequacy,	   it	   has	   already	   come	   under	   criticism	   by	  WCPFC	  members	  due	  to	  a	  lack	  of	  clearly	  defined	  fleet	  obligations	  and	  ambiguity	  in	  the	  spatial	  extent	  of	  this	  measure	  (WCPFC	  2013b).	  	  	   The	   IATTC,	  which	   ranks	   among	   the	   top	   RFMOs	  with	   regard	   to	   performance	   in	  governing	   bycatch	   and	   discards	   (Gilman	   et	   al.	   2012),	   is	   the	   only	   RFMO	   providing	  cumulative	  annual	  data	  sets	  on	  discarding	  within	   its	   fisheries	  statistics24.	  On	  the	  other	  hand,	   while	   the	   WCPFC	   does	   undertake	   various	   studies	   with	   regard	   to	   bycatch	   and	  discard	   rates,	   these	   data	   are	   neither	   consistent	   nor	   standardized,	  which	   often	  makes	  them	  difficult	  to	  interpret	  and	  apply.	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  24Since	   1993,	   the	   IATTC	   has	   included	   reported	   discards	   of	   both	   tuna	   and	   bycatch	   associated	   with	   the	  purse	  seine	  vessels	  larger	  than	  350	  GT	  in	  its	  annual	  Fisheries	  Report.	  	  92	  4 |	  THE	  BEAUTIFUL	  SIMPLICITY	  OF	  THE	  THING	  Here,	  then,	  is	  a	  great	  mystery.	  For	  you	  who	  love	  the	  little	  prince,	  as	  for	  me,	  nothing	  in	  the	  universe	  can	  be	  the	  same	  if	  somewhere—we	  do	  not	  know	  where—a	  sheep	  we	  have	  never	  met	  has,	  or	  has	  not,	  eaten	  a	  rose.	  -­‐Antoine	  de	  Saint-­‐Exupéry,	  The	  Little	  Prince	  	   93	  INTRODUCTION	  The	  role	  of	  stock	  assessments	  	   Studying	   and	   monitoring	   animals	   in	   an	   aquatic	   environment	   is	   an	   innately	  challenging	   task;	   one	   that	   is	   perhaps	   best	   encapsulated	   by	   fisheries	   scientist	   John	  Shepherd	  who	  said	  that	  managing	  fish	  stocks	  was	  analogous	  to	  “managing	  a	   forest,	   in	  which	  the	  trees	  are	  invisible	  and	  keep	  moving	  around”1.	  Nonetheless,	  understanding	  the	  dynamics	  of	  any	  commercially	  valuable	   fish	  stock	   is	  essential	   for	  both	  the	  people	  who	  depend	  on	  the	  productivity	  of	  a	   fishery	   for	   income	  and	  food,	  and	  also	   for	  maintaining	  the	   health	   of	   the	   marine	   ecosystem	   as	   a	   whole.	   Although	   scientists	   and	   managers	  typically	   cannot	   count	   each	   individual	   fish,	   this	   does	   not	   mean	   that	   stock	   size	   is	  impossible	  to	  estimate.	  Rather,	  it	  simply	  means	  that	  a	  different	  methodology	  is	  required	  for	   accomplishing	   this	   task.	   Therefore,	   one	   way	   in	   which	   scientists	   and	   fisheries	  managers	  attempt	  to	  understand	  the	  structure	  and	  health	  of	  fish	  populations	  is	  through	  the	  undertaking	  of	  stock	  assessments	  using	  mathematical	  models.	  	  	   At	   their	   most	   basic,	   technical	   stock	   assessments	   are	   meant	   to	   offer	   a	   detailed	  array	  of	   information	  to	  fisheries	  managers	  such	  that	  they	  can	  analyse	  policy	  trade-­‐offs	  and	   make	   the	   best	   choices	   for	   a	   given	   stock	   depending	   on	   the	   objectives	   of	   its	  associated	  fishery	  and/or	  its	  ecological	  status	  (Walters	  and	  Martell	  2004).	  Quantitative	  stock	  assessments	  help	  determine	  the	  maximum	  possible	  catch	  that	  can	  be	  attained	  and	  maintained	  indefinitely	  without	  overexploitation	  (Walters	  and	  Martell	  2004).	  This	  target	  (or	  limit)	  value	  is	  known	  as	  the	  maximum	  sustainable	  yield	  (MSY).	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  1From	  an	  unpublished	  lecture	  at	  Princeton	  University	  (c.	  1978).	  Full	  quote	  available	  from:	  http://jgshepherd.com/thoughts	  	   94	  Population	  dynamics	  of	  fish	  stocks	  	   When	  a	  new	  environment	   is	   first	   inhabited	  by	  a	  group	  of	   individuals,	   the	  size	  of	  this	  population	  has	   the	  potential	   to	   increase	   in	  biomass	  until	   it	   can	  no	   longer	  expand	  because	  of	  environmental	  limitations	  (i.e.,	  resource	  availability	  and	  space)	  (Odum	  1953).	  The	   rate	   at	   which	   this	   population	   grows	   is	   known	   as	   the	   intrinsic	   rate	   of	   population	  increase	  (𝑟),	  and	  the	  upper	  biomass	  limit	  of	  this	  population	  is	  referred	  to	  as	  its	  carrying	  capacity	  (𝑘).	  i. Carrying	  capacity	  (𝑘)	  	   Whether	  aquatic	  or	  terrestrial,	  all	  biological	  systems	  have	  a	  carrying	  capacity.	  (This	  level	  may	  vary	  around	  some	  mean,	  but	  here	  it	  will	  be	  assumed	  constant.)	  In	  the	  case	  of	  fish,	   adequate	   consideration	  of	   the	  underlying	  biological	   conditions	  of	   this	   state	   for	   a	  given	  stock	  has	  important	  applications	  for	  fisheries	  and	  management.	  Typically,	  a	  virgin	  (i.e.,	   unfished)	   stock	   is	   considered	   to	   be	   at	   carrying	   capacity.	   In	   this	   state,	   natural	  mortality	   (i.e.,	   death	   due	   to	   predation	   or	   old	   age)	   is	   equal	   to	   recruitment	   (i.e.,	   the	  number	   of	   young	   fish	   that	   survive	   to	   enter	   the	   stock	   each	   year2).	   However,	  with	   the	  onset	   of	   fishing	   effort	   (and	   thus	   additional	  mortality	   from	   fishing),	   a	   stock’s	   biomass	  decreases	  to	  below	  its	  carrying	  capacity,	  and	  the	  dynamics	  of	  the	  system	  (i.e.,	   the	  age	  composition	  of	  individuals	  and	  recruitment)	  are	  altered	  (Ricker	  1975).	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  2The	  age	  of	  recruitment	  varies	  by	  species,	  but	  it	  is	  typically	  considered	  to	  be	  when	  an	  individual	  is	  capable	  of	  being	  caught	  by	  fishing	  gear	  or	  at	  least	  appeared	  on	  the	  fishing	  ground	  (i.e.,	  has	  reached	  a	  certain	  size).	  95	  ii. Intrinsic	  rate	  of	  population	  increase	  (𝑟)One	  of	  the	  main	  population-­‐level	  responses	  to	  the	  increased	  space	  and	  resources	  incurred	   by	   fishing	   mortality	   changes	   is	   in	   growth.	   The	   speed	   at	   which	   this	   biomass	  expansion	   occurs	   in	   a	   given	   environment	   in	   the	   absence	   of	   density-­‐dependent	   forces	  (e.g.,	  competition)	  is	  known	  as	  the	  intrinsic	  rate	  of	  population	  increase	  (𝑟)	  (Birch	  1948;	  Odum	  1953).	  	  Depending	   on	   the	   taxon	   (i.e.,	   viruses	   to	   whales)	   to	   which	   a	   species	   belongs,	  differences	   between	   respective	   intrinsic	   rates	   of	   population	   increase	   can	   span	   over	  twenty	  orders	  of	  magnitude	  (Blueweiss	  et	  al.	  1978;	  Pauly	  1984).	  This	  variation	  is	  due	  to	  a	  variety	  of	  life	  history	  traits,	  especially	  the	  underlying	  key	  factor	  that	  influences	  growth:	  body	   size	   (Fenchel	   1974;	   Blueweiss	   et	   al.	   1978).	   Species	  with	   lower	  mean	   adult	   body	  weights	  will	   tend	   to	  have	   faster	   rates	  of	  population	  growth.	   Thus,	   in	   terms	  of	  marine	  organisms,	   the	   intrinsic	   rate	   of	   population	   increase	   for	   fishes	   is	  much	  higher	   than	   for	  whales	  (Pauly	  1984).	  However,	  even	  within	  the	  families	  of	  these	  classes,	  differences	  in	  𝑟	  exist.	  Among	  the	  fishes,	  there	  is	  a	  correlation	  between	  life	  history	  traits	  and	  population	  growth	   (Denney	   et	   al.	   2002).	   Specifically,	   tunas	   have	   different	   life	   history	   strategies,	  depending	  on	  their	  primary	  habitat.	  At	  the	  individual	  level,	  tropical	  tunas	  (e.g.,	  yellowfin	  and	   skipjack)	   grow	   faster	   but	   ultimately	   attain	   a	   lower	   mean	   body	   weight	   than	   sub-­‐tropical	  (e.g.,	  albacore)	  and	  temperate	  species	  (e.g.,	  bigeye	  and	  bluefin)	  (Fromentin	  and	  Fonteneau	   2001).	   Combined	   with	   year-­‐round	   breeding	   in	   a	   warm	   and	   productive	  environment,	  these	  attributes	  allow	  for	  fast	  population	  growth.	  Conversely,	  temperate	  	   96	  tunas	  live	  longer	  and	  have	  a	  later	  age	  of	  maturity	  than	  those	  found	  in	  tropical	  waters.	  In	  addition,	   some	   temperate	   tunas	   (i.e.,	   the	  bluefins:	  T.	  orientalis	  and	  T.	  maccoyii)	  make	  seasonal	  migrations	   to	   specific	  warm-­‐water	   spawning	   grounds	   (Shadwick	   et	   al.	   2013),	  thus	  further	  affecting	  reproduction	  frequently.	  	  The	  Schaefer	  production	  model	  	   In	   1954,	   Milner	   B.	   Schaefer	   developed	   one	   of	   the	   most	   simple—yet	   useful—fisheries	  dynamics	  models.	  This	  model	  is	  capable	  of	  explaining	  the	  relationship	  between	  stock-­‐recruitment	   dynamics,	   compensatory	   density-­‐dependence	   in	   population	   growth	  which	   results	   in	   surplus	   production3,	   and	   the	   way	   in	   which	   fisheries	   can	   operate	  sustainably	  by	  utilizing	  such	  surplus	  yield	  at	  its	  maximum	  (i.e.,	  fish	  at	  MSY).	  	  	   As	  is	  true	  for	  most	  biological	  systems,	  population	  growth	  in	  fish	  is	  assumed	  to	  be	  logistic	  in	  nature	  (Fig.	  4-­‐1):	  𝐵? = 𝑘1+ 𝑘 − 𝐵?𝐵? 𝑒? ™ 	   ...Eq.	  1	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  3Surplus	  production	  occurs	  when	  recruitment	  to	  the	  population	  is	  greater	  than	  mortality,	  thus	  allowing	  for	  population	  growth.	  	  	   97	  	  	  Figure	  4-­‐1.	  Logistic	  growth	  curve	  of	  a	  hypothetical	  fish	  population.	  	  	  where	  𝐵?	  is	  the	  biomass	  at	  time	  t,	  𝑘	  is	  the	  carrying	  capacity,	  𝐵?	  is	  the	  initial	  biomass	  (at	  t	  =	  0)	  and	  𝑟	  is	   the	   intrinsic	   rate	  of	  population	   increase.	  This	  shows	  the	  propensity	  of	  a	  population	   to	   grow	   slowly	   when	   there	   are	   few	   individuals	   (since	   it	   is	   limited	   by	  successful	   reproduction	   events)	   until	   a	   density	   threshold	   is	   reached	   allowing	   for	   the	  population	   biomass	   to	   rapidly	   increase.	   As	   the	   population	   size	   approaches	   carrying	  capacity,	  growth	  slows	  and	  ultimately	  reaches	  equilibrium	  at	  𝑘.	  	  	   To	  express	  the	  way	  in	  which	  the	  rate	  of	  population	  growth	  changes	  with	  respect	  to	  the	  size	  of	  the	  population,	  we	  use	  the	  first	  derivative	  of	  Equation	  1:	  𝑑𝐵𝑑𝑡 = 𝑟𝐵 1− 𝐵𝑘 	   …Eq.	  2	  k  	   98	  	  Figure	  4-­‐2.	  Schaefer’s	  surplus-­‐production	  function.	  This	  parabolic	   function	   (Fig.	  4-­‐2)	   shows	   that	  when	   the	  population	  has	   few	   individuals,	  the	  biomass	   is	   too	   small	   to	   result	   in	  a	  high	  growth	   rate	   (i.e,	  𝑟𝐵   ≈ 0).	  Conversely,	   the	  growth	   rate	   also	   decreases	   to	   0	  when	   the	  biomass	   approaches	   carrying	   capacity	   (i.e.,	  1− ?? ≈ 0)	  since	  there	  is	  no	  room	  left	  for	  new	  individuals	  to	  enter	  the	  population.	  While	  all	   values	   along	   the	   curve	   represent	   surplus	   production,	   population	   growth	   is	   at	   its	  maximum	  when	  the	  population	  biomass	  is	  at	  half	  of	  the	  carrying	  capacity.	  	   Sustainable	   fishing	  occurs	  when	   the	  yield	   (𝑌)	   is	  equal	   to	   surplus	  production	   (see	  Eq.	  3),	  since	  it	  is	  here	  when	  recruitment	  is	  equal	  to	  total	  mortality	  (natural	  +	  fishing):	  𝑌 = 𝑟𝐵(1− 𝐵𝑘)	   …Eq.	  3	  Since	  surplus	  production	  is	  a	  function	  of	  population	  size	  (see	  Fig.	  4-­‐2),	  the	  sustainable	  yield	  can	  be	  maximized	  when	  𝐵™? = ??.	  Substituting	  𝐵™? 	  in	  Eq.	  3:	  MSY	  0	  	   k  99	  𝑀𝑆𝑌 = 𝑟𝑘2(1−𝑘2𝑘)	  …Eq.	  4MSY =𝑟 ∗ 𝑘4...Eq.	  5	  	   Thus,	  given	  only	  two	  key	  population	  growth	  parameters:	  𝑟	  and	  𝑘,	  it	  is	  possible	  to	  estimate	  MSY	  for	  a	  given	  stock.	  The	  Catch-­‐MSY	  method	  Based	  on	  the	  Schaefer	  (1954)	  production	  model	  described	  above,	  the	  Catch-­‐MSY	  method	  was	  designed	  by	  Martell	  and	  Froese	  (2012)	  in	  an	  effort	  to	  estimate	  the	  MSY	  for	  data-­‐poor	   or	   previously	   unassessed	   fish	   stocks.	   In	   many	   regions	   of	   the	   world	   (e.g.,	  developing	   countries	   with	   remote	   coastal	   fisheries),	   catch	   data	   may	   be	   the	   only	  available	   information	   (Pauly	   2013)	   and	   the	   personnel,	   funding,	   and/or	   technology	  required	  to	  conduct	  a	  comprehensive	  population	  analysis	  may	  not	  be	  available.	  As	  such,	  this	  method	  may	   serve	   as	   a	   valuable	   first	   step	   in	   fisheries	  management.	   From	  only	   a	  time	  series	  of	  catch,	  ranges	  of	  potential	  𝑟	  and	  𝑘	  values,	  and	  a	  range	  of	  the	  current	  stock	  level	   relative	   to	   its	   initial	   biomass	   (𝐵™????? /𝐵?),	   this	   model	   is	   capable	   of	   estimating	  more	  precise	  values	  of	  𝑟	  and	  𝑘,	  and	  generating	  the	  MSY	  for	  a	  given	  stock.	  For	  the	  Catch-­‐MSY	  method,	  the	  intrinsic	  rate	  of	  population	  increase	  is	  assumed	  to	  be	  synonymous	  with	  a	  stock’s	  ability	  to	  rebound	  following	  depletion	  fishing	  (i.e.,	  its	  	  	   100	  Table	   4-­‐1.	   Default	   values	   for	   the	   maximum	   intrinsic	   rate	   of	   population	   growth	   based	   on	   resilience	  classifications	  (very	  low	  to	  high)	  from	  FishBase.	  (Source:	  Martell	  and	  Froese	  2012).	  	  Table	  4-­‐2.	  Default	  values	  for	  initial	  and	  final	  biomasses	  (Martell	  and	  Froese	  2012).	  	  resilience).	   As	   such,	   in	   order	   to	   approximate	  𝑟,  resilience	   classifications	   from	   FishBase	  (www.fishbase.org)	  are	  each	  given	  a	  default	  range	  (Table	  4-­‐1),	  and	  this	  range	  is	  applied	  to	  the	  stock	  based	  on	  its	  resilience.	  	   To	  estimate	  the	  carrying	  capacity,	  the	  default	  limits	  are	  defined	  as	  the	  maximum	  recorded	  catch	  (lower	   limit)	  and	  100	  times	  the	  maximum	  observed	  catch	  (upper	   limit)	  for	  the	  observed	  stock	  (𝑘 =   𝐶™?   	  to	  100 ∗ 𝐶™? ).	  	   For	  the	  first	  and	  last	  years	  in	  the	  time	  series,	  a	  default	  range	  of	  relative	  biomasses	  (𝐵?and	  𝐵™????? )	  is	  applied	  based	  on	  the	  ratio	  of	  total	  catch	  to	  maximum	  catch	  (Table	  4-­‐2).	  	  	   The	   model	   is	   then	   used	   to	   calculate	   annual	   biomass	   estimates	   from	   randomly	  selected	  𝑟 −	  𝑘	  pairs	   (see	   Eq.	   6)	   and	   to	   eliminate	   any	   pairs	   that	   result	   in	   the	   stock	  collapsing	  or	  exceeding	  the	  carrying	  capacity	  when	  fitted	  with	  the	  observed	  catch	  time	  series	  (Fig.	  4-­‐3):	  Resilience( High( Medium( Low( Very(low(!  (year81)( 0.6$1.5' 0.2$1' 0.05$0.5' 0.015$0.1'!! Catch/max)catch) B/k$Initial)year) <!0.5! 0.5&0.9!! ≥!0.5! 0.3&0.6!Final)year) >!0.5! 0.3&0.7!! ≤!0.5! 0.01&0.4!!101	  𝐵???   = [𝐵? + 𝑟  𝐵? 1−𝐵?𝑘−   𝑐?]𝑒 ™ 	  …Eq.	  6From	   the	   viable	  𝑟 −	  𝑘	  pairs	   (i.e.,	   likelihood	   =	   1),	   the	   geometric	  means	   of	  𝑟	  and	  𝑘,	   and	  the	  corresponding	  MSY	  value	  are	  computed	  (see	  Eq.	  5).	  	  Purpose	  of	  study	  This	  method	  lends	  further	  evidence	  that	  catch	  data	  can	  be	  translated	  into	  stock	  monitoring	   principles.	   Since	   most	   full	   stock	   assessments	   are	   conducted	   for	   fish	  populations	  with	  limited	  distribution	  in	  coastal	  ecosystems,	  they	  typically	  encapsulate	  	  Figure	  4-­‐3.	  Initial	  ranges	  of	  𝑟	  and	  𝑘,	  and	  the	  𝑟−	  𝑘	  combinations	  that	  are	  compatible	  with	  the	  time	  series	  of	  catch	  (n=	  2,897)	  for	  albacore	  tuna	  in	  the	  South	  Pacific	  Ocean.	  The	  geometric	  means	  of	  viable	  𝑟	  and	  𝑘	  values	  are	  used	  to	  compute	  MSY,	  and	  their	  variance	  is	  used	  to	  estimate	  the	  uncertainty	  of	  the	  estimate.	  102	  only	   a	   few	   fisheries	   and	   rarely	  more	   than	   two	   counties.	   Given	   their	   highly	  migratory	  nature,	  ocean-­‐wide	  distribution,	   and	  unique	   life	  histories,	   as	  well	   as	   the	  multinational	  nature	   of	   the	   associated	   fisheries,	   assessing	   pelagic	   fish	   stocks	   is	   an	   especially	  challenging	  task	  for	  fisheries	  managers.	  Although	  Martell	  and	  Froese	  (2012)	  suggest	  that	  the	  Catch-­‐MSY	  method	  is	  not	  a	  substitute	  for	  stock	  assessments,	  this	  study	  explores	  the	  accuracy	  and	  application	  of	   this	   relatively	  simple	  method	  with	  regard	  to	  Pacific	  Ocean	  pelagic	   species	   by	   comparing	   estimated	   MSY	   targets	   to	   those	   from	   complete	   stock	  assessments.	  Since	  the	  majority	  of	  species	  assessed	  in	  Martell	  and	  Froese	  (2012)	  were	  classified	  to	  have	  ‘medium’	  resilience,	  the	  further	  analysis	  of	  ‘low’	  and	  ‘very	  low’	  species	  such	  as	  sharks	  and	  tunas	  should	  provide	  additional	  understanding	  of	  the	  accuracy	  of	  this	  model.	  METHODS	  Catch	  data	  Catch	   time	   series	   for	   seven	   commercially	   important	   tuna	   stocks	   (five	   species),	  two	  shark	  species,	  and	  three	  billfishes	  were	  used	  in	  this	  analysis.	  With	  the	  exception	  of	  southern	  bluefin	   tuna,	  all	  of	   these	  species	  were	   from	  populations	   found	  exclusively	   in	  the	  Pacific	  Ocean.	  	  In	   order	   to	   ensure	   that	   the	   output	   estimate	   of	   MSY	   from	   the	   Catch-­‐MSY	  algorithm	   could	  be	  directly	   compared	  with	   the	   stock	   assessment	   estimates,	   the	   catch	  data	   provided	   in	   the	   most	   recent	   publically	   available	   stock	   assessments	   for	   these	  species	   were	   used:	   southern	   bluefin	   (CCSBT	   2011),	   Pacific	   bluefin	   (ISC	   2013b),	   South	  Pacific	   albacore	   (Hoyle	   et	   al.	   2012),	   North	   Pacific	   albacore	   (ISC	   2011),	   West	   Pacific	  	   103	  bigeye	  (Davies	  et	  al.	  2011),	  East	  Pacific	  bigeye	  (Aires-­‐da-­‐Silva	  and	  Maunder	  2012),	  West	  Pacific	  yellowfin	  (Langley	  et	  al.	  2011),	  East	  Pacific	  yellowfin	  (Aires-­‐da-­‐Silva	  and	  Maunder	  2012a),	   silky	   shark	   (Rice	  et	   al.	  2012),	   blue	   shark	   (ISC	   2013a),	   swordfish	   (Brodziak	   and	  Ishimura	  2010),	  blue	  marlin	  (ISC	  2013b),	  and	  striped	  marlin	  (Lee	  et	  al.	  2013).	  	  	   Although	  all	  of	  these	  stock	  assessments	  presented	  multiple	  fishing	  scenarios	  and,	  in	  some	  cases,	  different	  catch	  time	  series,	   the	  catch	  data	  used	   in	  this	  analysis	  and	  the	  projected	   MSY	   used	   as	   for	   comparison	   were	   from	   the	   ‘reference’	   case	   in	   each	  assessment.	  Since	  all	  of	  the	  stock	  assessments	  provided	  only	  graphical	  representation	  of	  the	  catch	  over	  time,	  GraphClick	  software	  was	  used	  to	  extract	  the	  data	  (see	  Tables	  8	  and	  9	  in	  Appendix).	  Catch-­‐to-­‐MSY	  analysis	  	   The	  original	   algorithm	  developed	  by	  Martell	   and	   Froese	   (2012)	   has	   since	  been	  incorporated	   into	   the	   ‘Tools’	   section	   of	   FishBase,	   the	   publicly	   available	   online	  encyclopedia	  of	  fish.	  As	  such,	  in	  order	  to	  simultaneously	  test	  the	  efficiency	  and	  usability	  of	  this	  open-­‐source	  feature,	  this	  analysis	  was	  performed	  through	  the	  FishBase	  website	  (see	  www.fishbase.org).	  	  	   Resilience	  estimates	  that	  served	  as	  the	   life	  history	   input	  variable	  for	  estimating	  the	  rate	  of	  population	  increase	  (𝑟)	  were	  obtained	  from	  FishBase	  for	  each	  species	  (Table	  4-­‐3).	   The	   reference	   case	   catch	   data	   were	   uploaded	   to	   FishBase	   in	   the	   same	   annual	  format	   in	   which	   they	   were	   extracted	   from	   the	   stock	   assessments.	   No	   additional	  assumptions	   about	   population	   dynamics	   or	   stock	   structure	  were	  made	   for	   any	   of	   the	  Catch-­‐MSY	  analyses,	  nor	  were	  any	  process	  errors	  added.	  	  104	  RESULTS	  A	  comparison	  of	  the	  stock	  assessment	  estimates	  and	  the	  values	  calculated	  using	  the	  Catch-­‐MSY	  method	  is	  provided	  in	  Table	  4-­‐3.	  From	  10,000	  iterations	  of	  the	  algorithm,	  the	   number	   of	   viable	  𝑟 −	  𝑘 	  combinations	   for	   each	   species	   ranged	   from	   82	   (striped	  marlin)	  to	  3,108	  (blue	  shark),	  with	  an	  average	  of	  1,800	  possible	  𝑟 −	  𝑘	  pairs	  per	  species.	  Overall,	   half	   of	   the	   mean	   MSY	   values	   predicted	   by	   the	   Catch-­‐MSY	   method	   were	  overestimated	  (by	  1-­‐63%),	  and	  half	  were	  underestimated	  (by	  8-­‐200%).	  Nonetheless,	  the	  overall	   difference	   between	   the	   MSY	   suggestion	   provided	   in	   the	   complete	   stock	  assessment	   and	   the	   average	   MSY	   output	   from	   the	   Catch-­‐MSY	   method	   was	   almost	  negligible	  for	  most	  species	  (Figure	  4-­‐4,	  Table	  4-­‐3).	  	  Table	   4-­‐3.	   Input	   resilience	   classifications	   from	   FishBase	   and	   mean	   MSY	   predictions	   from	   the	   stock	  assessment	  and	  Martell	  and	  Froese	  method	  (2012).	  	  Stock& Resilience& Stock&assessment&MSY&(t)&Catch5input&MSY&(t)& Stock&status&Pacific&bluefin&(PBT)& Low& 3& &21,450&& Overfished&Southern&bluefin&(SBT)& Low& 34,500& &28,087&& Overfishing&no&longer&occurring&&WPO&bigeye&(BET3W)& Low& 76,760& &125,306&& Overfished&EPO&bigeye&(BET3E)& Low& 82,246& &94,004&& Overfished&WPO&yellowfin&(YFT3W)& Medium& 538,800& &498,613&& Not&overfished&EPO&yellowfin&(YFT3E)& Medium& 262,642& &265,336&& 3&NPO&albacore&(ALB3N)& Medium& 3& &88,517&& Not&overfished&SPO&albacore&(ALB3S)& Medium& 133,200& &65,878&& Not&overfished&WPO&skipjack&(SKJ)& Medium& 1,500,000& &1,511,848&& Not&overfished&Blue&shark&(B3SHK)& Very&low& 58,000& &36,207&& Not&overfished&Silky&shark&(S3SHK)& Very&low& 1,885& &2,929&& Overfished&Blue&marlin&(B3MAR)& Low& 19,459& &18,690&& Not&overfished&Striped&marlin&(S3MAR)& Medium& 5,378& &6,793&& Overfished&Swordfish&(SWO)& Low& 34,500& &15,674&& Not&overfished&&	   105	  	  Figure	  4-­‐4.	  Comparison	  of	  MSY	  estimates	  (log	  t)	  using	  stock	  assessment	  and	  Martell	  and	  Froese	  (2012)	  Catch-­‐MSY	  method.	  Error	  bars	  represent	  “high”	  and	  “low”	  ranges	  defined	  in	  the	  stock	  assessments	  and	  2	  standard	  deviations	  in	  the	  Catch-­‐MSY	  method.	  Species	  are	  colour-­‐coded	  based	  on	  resilience	  classification:	  blue=	  very	  low,	  green=low,	  orange=	  medium;	  see	  Table	  4-­‐4	  for	  species	  abbreviations.	  	  	   Regardless	  of	  the	  length	  of	  the	  catch	  time	  series	  used,	  the	  MSY	  generated	  by	  the	  Catch-­‐MSY	   algorithm	   for	   species	  with	   ‘very	   low’	   and	   ‘low’	   resilience	  was	   consistently	  most	   different	   (i.e.,	   ether	   over-­‐	   or	   underestimated)	   from	   the	   MSY	   suggested	   by	   the	  complete	  stock	  assessment	  report.	  	  With	   regard	   to	   tuna	   species,	   the	   Catch-­‐MSY	   model	   best	   matched	   the	   stock	  assessment	  MSY	   targets	   for	   yellowfin	   (both	   stocks)	   and	   skipjack.	   The	  model	   had	   the	  greatest	   overestimation	  of	  MSY	   for	   bigeye	   (both	   stocks)	   and	  underestimated	  MSY	   for	  southern	   bluefin	   and,	   more	   noticeably,	   albacore.	   In	   terms	   of	   billfish,	   the	   Catch-­‐MSY	  algorithm	   underestimated	   the	   MSY	   for	   both	   swordfish	   and	   blue	   marlin,	   yet	   slightly	  overestimated	  the	  MSY	  for	  striped	  marlin.	  Similarly,	  the	  MSY	  target	  for	  blue	  shark	  was	  BET$W&BET$E&YFT$E& YFT$W&ALB$S&SKJ&B$SHK&S$SHK&SWO&B$MAR&S$MAR&SBT&3&4&5&6&7&&3&& &4&& &5&& &6&& &7&&MSY$from$catch$input$method$(log$t)$MSY$from$stock$assessment$(log$t)$	   106	  estimated	  to	  be	  lower	  using	  the	  Catch-­‐MSY	  method,	  while	  the	  MSY	  target	  for	  silky	  shark	  was	  estimated	  to	  be	  higher.	  	   The	   complete	   assessments	   for	   two	   stocks	   used	   in	   this	   analysis	   did	   not	   estimate	  MSY;	  therefore	  no	  comparison	  could	  be	  made	  for	  these	  species.	  Nonetheless,	  the	  values	  generated	  by	  the	  Catch-­‐MSY	  algorithm	  were	  21,450	  t	  for	  Pacific	  bluefin,	  and	  88,517	  t	  for	  the	  North	  Pacific	  stock	  of	  albacore.	  DISCUSSION	  	   This	   analysis	   shows	   that	   for	   pelagic	   species	   in	   the	   Pacific	  Ocean,	   the	   Catch-­‐MSY	  algorithm	   projects	   a	   MSY	   value	   similar	   to	   that	   of	   the	   complete	   stock	   assessment.	  Independent	  of	  the	  length	  of	  the	  catch	  time	  series,	  MSY	  values	  for	  species	  with	  medium	  resilience	  were	  best	  predicted	  by	  the	  model,	  a	  finding	  that	  corroborates	  the	  assertions	  of	  Martell	  and	  Froese	  (2012).	  Accuracy	  of	  the	  Catch-­‐MSY	  algorithm	  for	  certain	  stocks	  	   In	  the	  context	  of	  pelagic	  fishes,	  fast	  population	  growth	  rates	  make	  tropical	  tunas	  more	  resilient	  than	  sub-­‐tropical	  and	  temperate	  species.	  This	  ultimately	  means	  they	  are	  less	   susceptible	   to	   overfishing	   as	   well	   (Fromentin	   and	   Fonteneau	   2001).	   Similar	   to	  temperate	  tunas,	  most	  sharks	  also	  have	   low	  resilience,	  a	  characteristic	   that	   is	  strongly	  linked	   to	   high	   age	   at	   maturity	   (Smith	   et	   al.	   1998)	   and	   thus,	   a	   slow	   intrinsic	   rate	   of	  population	  increase.	  Like	  temperate	  tunas,	  elasmobranchs	  are	  therefore	  believed	  to	  be	  highly	   vulnerable	   to	   overfishing	   (Hoenig	   and	   Gruber	   1990;	   Schindler	   et	   al.	   2002).	   As	  discussed	   by	   Martell	   and	   Froese	   (2012)	   the	   Catch-­‐MSY	   model	   is	   less	   accurate	   at	  107	  predicting	   MSY	   for	   species	   with	   low	   or	   very	   low	   resilience.	   The	   findings	   here	  demonstrated	   this,	   as	   the	  MSY	  values	   for	  both	   shark	   species	   (i.e.,	   very	   low	   resilience)	  were	  observably	  dissimilar	  compared	  to	  the	  stock	  assessments.	  	  The	   south	   Pacific	   stock	   of	   albacore	   tuna	   had	   the	   worst	   prediction	   among	   the	  medium	   resilience	   species.	   However,	   it	   is	   worth	   pointing	   out	   that	   several	   substantial	  revisions	  were	  made	  to	  the	  assumptions	  in	  the	  complete	  stock	  assessment	  compared	  to	  the	  previous	  year,	  both	   in	   terms	  of	   the	  catch	  and	  effort	  data	   for	   certain	   fisheries	  and	  input	   biological	   parameters	   (Hoyle	   et	   al.	   2012)4.	   The	   authors	   of	   the	   2012	   assessment	  suggest	  that	  this	  new	  information	  offers	  an	  improvement	  in	  the	  fit	  of	  key	  data	  sets,	  but	  also	  that	  there	  is	  high	  uncertainty	  surrounding	  the	  growth	  curve	  for	  this	  stock.	  Using	  this	  new	   information,	   the	   MSY	   suggested	   by	   the	   2012	   stock	   assessment	   was	   133,200	   t,	  compared	  to	   the	  2011	  MSY	  output	  of	  85,130	  t.	  This	  analysis	  used	  the	  MSY	   from	  2012	  estimate	  as	   its	   reference	  point,	  however	   if	   the	  2011	  value	  had	  been	  used	   instead,	   the	  accuracy	  of	  the	  MSY	  generated	  by	  the	  Catch-­‐MSY	  model	  (88,517	  t)	  would	  have	  been	  on	  par	  with	  all	  other	  medium	  resilience	  species.	  Given	  the	  precision	  of	  the	  MSY	  algorithm	  with	   all	   other	   stocks	   of	   medium	   resilience,	   and	   the	   substantial	   deviation	   in	   MSY	  estimates	  between	  two	  consecutive	  years	  in	  the	  south	  albacore	  assessment,	   it	  may	  be	  possible	   that	   (since	   the	   growth	   of	   an	   individual	   is	   ultimately	   related	   to	   overall	  population	  resilience)	  the	  revisions	  made	  to	  the	  growth	  estimates	  in	  the	  complete	  stock	  4Specifically,	  modifications	   to	   the	   stock	   assessment	   reference	   case	   from	   the	  2011	   to	  2012	  assessments	  included:	   1)	   revision	   of	   CPUE	   longline	   indices,	   as	   well	   as	   catch	   and	   size	   data;	   2)	   changes	   in	   the	   ogive	  defining	  spawning	  potential	  at	  age	  and	  the	  growth	  curve;	  3)	  the	  assumed	  steepness	  was	  increased	  from	  0.75	  to	  0.8;	  and	  4)	  a	  lognormal	  bias	  adjustment	  was	  applied	  to	  the	  mean	  recruitment	  estimate.	  	  	   108	  assessment	   are	   responsible	   for	   these	   conflicting	  MSY	   estimates.	   Conversely,	   it	   is	   also	  possible	  that	  this	  outcome	  is	  purely	  coincidental.	  	  	   Martell	   and	   Froese	   (2012)	   suggest	   another	   potential	   caveat	   in	   the	   Catch-­‐MSY	  method:	   it	  may	  be	   less	  accurate	   in	  cases	  where	  catch	  times	  series	  are	  either	  short,	  or	  lack	  contrast.	  In	  this	  analysis,	  the	  stock	  with	  the	  least	  overall	  fluctuation	  in	  annual	  catch	  was	  swordfish.	  However,	  this	  did	  not	  seem	  to	  impact	  the	  accuracy	  of	  the	  MSY	  estimate	  in	  this	  case.	  The	  shortest	  time	  series	  used	  in	  this	  analysis	  was	  that	  of	  silky	  shark	  (1994-­‐2009),	   which	   was	   one	   of	   the	   species	   with	   an	   overprediction	   of	   MSY.	   However,	   it	   is	  unclear	   how	   much	   of	   this	   deviation	   from	   the	   MSY	   of	   the	   full	   stock	   assessment	   is	  attributable	  to	  the	  length	  of	  the	  time	  series.	  CONCLUSIONS	  	   What	  is	  unique	  about	  this	  approach	  is	  that	  despite	  very	  wide	  ranges	  of	  potential	  𝑟	  and	  𝑘 	  estimates,	   the	   Catch-­‐MSY	   model	   is	   capable	   of	   substantially	   narrowing	   these	  ranges	   upon	   the	   inclusion	   of	   only	   a	   catch	   time	   series.	  While,	   naturally,	   this	   does	   not	  answer	  all	  the	  questions	  posed	  by	  fisheries	  managers	  nor	  give	  all	  the	  outputs	  included	  in	  complete	   assessments,	   it	   represents	   a	   solid	   starting	   point	   for	   ascertaining	   one	   of	   the	  most	  widely	  recognized	  management	  targets.	  	  	   Given	  that	  the	  results	  of	  this	  method	  are	  quite	  similar	  to	  those	  predicted	  for	  some	  of	   the	   world’s	   most	   commercially	   valuable	   fisheries,	   it	   is	   evident	   that	   catch	   data	  contains	  information	  that	  can	  be	  of	  value	  for	  management	  in	  the	  absence	  of	  other	  stock	  biomass	   indices.	   As	   such,	   obtaining	   accurate	   and	   complete	   catch	   time	   series	   is	   of	  paramount	  importance.	  109	  Although	  large	  migratory	  tuna	  and	  billfish	  are	  managed	  by	  RFMOs	  at	  the	  ocean-­‐scale,	   the	  high	   correlation	  between	   the	  Catch-­‐MSY	  estimate	   to	   the	  estimate	   from	   the	  complete	   stock	  assessment	   seen	   in	   this	  analysis	   suggests	   that	   this	  method	  may	  prove	  useful	   for	   regions	   with	   high	   neritic	   scombrid	   catches,	   but	   limited	   data	   processing	  capabilities	  and	  funding.	  In	  addition	  to	  testing	  the	  accuracy	  of	  the	  Catch-­‐MSY	  method	  as	  a	  whole,	  another	  underlying	  aim	  of	  this	  study	  was	  to	  use	  simple,	  publicly	  available	  data	  processing	   tools	   for	   the	   analysis.	   The	   rationale	   behind	   this	   basic	   approach	   was	   to	  demonstrate	  that	  even	  if	  a	  fisheries	  management	  unit	  operating	  with	  limited	  resources	  (both	  financial	  and	  technological),	  a	  generalized	  picture	  of	  management	  targets	  and	  key	  population	  parameters	  could	  still	  be	  obtained.	  Naturally,	  this	  concept	  would	  apply	  to	  all	  species,	  not	  only	  tunas	  and	  pelagics.	  110	  5 |	  THE	  PRIVILEGE	  TO	  KNOW	  ’People	  have	  forgotten	  this	  truth,’	  the	  fox	  said.	  ‘But	  you	  mustn’t	  forget	  it.	  You	  become	  responsible,	  forever,	  for	  what	  you	  have	  tamed.’	  -­‐Antoine	  de	  Saint-­‐Exupéry,	  The	  Little	  Prince	  	  	   111	  …The	  Duty	  to	  Act5	  	   Despite	  several	   limitations	   in	  data	  availability,	   the	  reconstructions	  presented	   in	  Chapters	   Two	   and	   Three	   provide	   a	   viable	   first	   attempt	   at	   improving	   the	   catch	   data	  associated	  with	  fisheries	  in	  the	  Pacific	  Ocean,	  as	  well	  as	  improving	  our	  understanding	  of	  how	   commercial	   tuna	   fishing	   impacts	  marine	  ecosystems	  at	   both	   the	   local	   and	  ocean	  level.	  A	  more	  comprehensive	  understanding	  of	  the	  magnitude	  of	  these	  issues	  will	  only	  be	   possible	   with	   improved	   record	   keeping	   and	   data	   availability	   provided	   by	   fisheries	  managers.	  Therefore,	  more	  than	  anything,	  the	  work	  of	  this	  thesis	  has	  shown	  an	  ongoing	  inadequacy	  of	  fisheries	  management	  bodies	  (both	  local	  and	  international)	  to	  adhere	  to	  their	   mandates	   of	   protecting	   marine	   environments	   and	   sustainably	   exploiting	   fish	  stocks.	   This	  has	   resulted	   in	   the	   subsequent	  overexploitation	  of	  marine	   life—especially	  sharks—to	  varying	  degrees.	  	  Given	  that	  between	  2001-­‐2007,	  there	  were	  29	  reported	  seizures	  of	  boats	  illegally	  shark	  fishing	  in	  the	  GMR	  (Carr	  et	  al.	  2013),	  and	  based	  on	  the	  shark	  catch	  determined	  by	  the	   Galápagos	   reconstruction,	   proactive	   and	   targeted	   shark	   conservation	   measures	  within	   the	   archipelago	   are	   currently	   inadequate,	   and	   their	   development	   should	   be	   of	  paramount	   importance.	   It	   is	   possible	   that	  both	   the	  quantity	  of	   sharks	   and	   the	   rate	  at	  which	  they	  are	  being	  extracted	  from	  the	  Galápagos	  archipelago	  are	  among	  the	  highest	  of	  any	  EEZ	  in	  the	  world.	  As	  discussed	  by	  Villalta-­‐Gómez	  (2013),	  the	  overall	  conservation	  status	   of	   the	   GMR	   is	   currently	   ‘unfavourable’	   and	   its	   management	   plan	   should	   be	  restructured.	   Nonetheless,	   it	   is	   encouraging	   to	   note	   the	   recent	   attention	   aimed	   at	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  5The	  full	  quote,	  “Those	  who	  have	  the	  privilege	  to	  know,	  have	  the	  duty	  to	  act”	  is	  commonly	  attributed	  to	  Albert	  Einstein	  (date	  and	  location	  unknown).	  	  112	  obtaining	   and	   integrating	   data	   on	   the	   marine	   species	   and	   environment,	   interactions	  with	  human	  activities,	   and	   the	  biophysical	   properties	  of	   the	  archipelago	   (Banks	  et	  al.,	  2012;	  Luna	  et	  al.,	  2013).	  Given	  both	  its	  intrinsic	  value	  as	  a	  highly	  biodiverse	  and	  endemic	  region,	  and	   its	  economic	  value	   in	   terms	  of	   tourism	  and	   fisheries,	  an	  ongoing	   focus	  on	  rebuilding	  sustainable	  fisheries	  will	  be	  essential	  for	  the	  long-­‐term	  health	  of	  the	  marine	  resources,	  and	  people,	  of	  the	  Galápagos	  Islands.	  	  	  RFMOs	  have	  come	  under	  considerable	  criticism	  in	  recent	  years,	  especially	  with	  regard	   to	   their	   inability	   to	   adequately	   manage	   stocks	   and	   enforce	   regulations	   and	  policies	   (McKelvey	   et	   al.	   2003;	   Allen	   2010;	   Cullis-­‐Suzuki	   and	   Pauly	   2010).	   Despite	  overarching	  objectives	  of	  providing	  optimal	  utilization	  and	  the	  conservation	  of	  High	  Seas	  fish	   stocks,	   there	   appears	   to	   be	   a	   strong	   disconnect	   between	   this	   mandate	   and	   its	  execution	  (Cullis-­‐Suzuki	  and	  Pauly	  2010).	  	  In	  addition	  to	  the	  high	  level	  of	  overexploited	  stocks	  that	  fall	  under	  their	  jurisdiction,	  the	  difficulties	  in	  obtaining	  basic	  data	  for	  Chapter	  Three	  suggest	  RFMOs	  provide	   inadequate	  and	   inconsistent	  catch	  statistics,	  particularly	  with	   regard	   to	   discards.	   Given	   their	   conceptual	   obligation	   to	   sustainably	  manage	   and	  conserve	   migratory	   fish	   stocks,	   RFMOs	   should	   be	   held	   responsible	   for	   collecting	   and	  publicizing	  all	  data	  pertaining	  to	  fishing	  practices	  associated	  with	  the	  fleets	  under	  their	  jurisdiction,	  since	  only	  they	  can	  provide	  this	  information	  at	  a	  spatial	  and	  temporal	  scale	  large	  enough	  to	  observe	  trends	  at	  the	  ocean	  level.	  With	  regard	  to	  enforcing	  quotas	  and	  minimizing	   opportunities	   for	   under-­‐reported	   catch	   data,	   the	   development	   and	  implementation	  of	  adequate	  observer	  coverage,	  especially	  for	  distant-­‐water	  longliners,	  should	  be	  of	  the	  highest	  priority	  for	  these	  management	  organizations.	  	  	   113	  	   Although	   data-­‐limited	   stock	   assessments	   have	   come	   under	   some	   criticism	  (Carruthers	  et	  al.	  2012),	  the	  Catch-­‐MSY	  model	  accomplishes	  the	  job	  it	  was	  designed	  to	  do.	  Despite	  the	  fact	  that	  primary	  objective	  of	  every	  fishery	  on	  Earth	  is	  to	  catch	  fish,	  and	  that	  catches	  the	  only	  data	  available	   in	  some	  cases	   (Pauly	  2013),	  additional	  criticism	  of	  using	  catch	  data	  to	  infer	  the	  health	  of	  a	  stock	  is	  ongoing	  (Hilborn	  and	  Branch	  2013).	  Yet,	  the	   Catch-­‐MSY	   algorithm	   consistently	   demonstrates	   that	   with	   minimal	   assumptions	  about	   life	  history	  parameters,	  even	  a	   time	  series	  of	   catch	  can	  yield	   results	   (e.g.,	  MSY)	  comparable	   to	   those	   projected	   by	   advanced	   stock	   assessment	   approaches.	   As	   such,	  ensuring	   that	   the	   input	   catch	   data	   set	   is	   accurate	   is	   of	   vital	   importance.	   Still,	   this	  information	  can	  only	  go	  so	  far.	  Ultimately,	  the	  responsibility	  of	  ensuring	  a	  stock	  is	  fished	  sustainably	   (at	   MSY	   or	   a	   different	   target)	   falls	   upon	   the	   fisheries	   management	   body	  overseeing	  that	  stock.	  	  Take	  arms	  against	  a	  sea	  of	  troubles6	  	  	   	  From	   the	  musings	   of	   Voltaire7,	   Albert	   Einstein,	   and	   Antoine	   de	   Saint-­‐Exupéry,	  the	   concept	   of	   taking	   responsibility	   for	   one’s	   ability—be	   it	   power	   or	   knowledge—is	  suggested	  as	  a	  vital	  aspect	  of	  humanity.	  Unfortunately,	   in	   the	  case	  of	   fisheries,	   this	   is	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  6From	  Act	  III;	  Scene	  I	  in	  Shakespeare’s	  Hamlet	  (1603):	  	  To	  be,	  or	  not	  to	  be,	  that	  is	  the	  question—	  Whether	  'tis	  Nobler	  in	  the	  mind	  to	  suffer	  The	  Slings	  and	  Arrows	  of	  outrageous	  Fortune,	  Or	  to	  take	  Arms	  against	  a	  Sea	  of	  troubles,	  And	  by	  opposing	  end	  them?	  	  7The	  quote,	  ‘Un	  grand	  pouvoir	  impose	  une	  lourde	  responsabilité’	  (A	  great	  power	  imposes	  a	  heavy	  responsibility)	  is	  attributed	  to	  Voltaire	  (see	  Œvres	  de	  Voltaire,	  Vol.	  48,	  1832). 	  	  114	  often	  not	  the	  case.	  Based	  on	  their	  highly	  migratory	  nature,	  specific	  spawning	  areas,	  and	  value	   on	   the	   global	  market,	   the	   tunas	   are	   likely	   the	   world’s	  most	   challenging	   fish	   to	  manage.	   Although	   this	   thesis	   did	   not	   directly	   analyse	   these	   issues,	   the	   following	  represents	  a	  summary	  of	   the	  key	  underlying	  concepts	   I	  have	  obtained	  and	  retained	   in	  undertaking	   this	   work,	   and	   my	   views	   on	   some	   of	   the	   most	   important	   issues	   facing	  Pacific	  Ocean	  tuna	  fisheries	  today.	  Given	  the	  high	  level	  of	  overexploitation	  in	  the	  Pacific,	  specifically	  with	  regard	  to	  larger	   tunas	   species,	   RFMOs	   are	   clearly	   unable	   to	   unilaterally	   manage	   these	   stocks.	  However,	   this	   does	   not	   mean	   that	   countries	   are	   therefore	   exempt	   from	   their	   own	  management	  responsibilities.	  Although	  the	  very	  nature	  of	  the	  ‘tragedy	  of	  the	  commons’	  (Hardin	   1968)	   suggests	   that	   multi-­‐player	   cooperation	   is	   unlikely	   in	   a	   common-­‐pool	  resource,	   such	  behaviour	   is	   not	   impossible.	   In	   the	  Pacific	   Islands,	   the	   Forum	  Fisheries	  Agency	  (FFA)	  is	  a	  testament	  to	  big	  picture	  foresight	  and	  collaboration.	  This	  international	  partnership	  (17	  members8)	  is	  working	  to	  ensure	  that	  the	  position	  (on	  conservation	  and	  management	  measures)	  of	   Island	  states	   is	  better	  represented	  than	   it	  would	  be	   if	  each	  country	  were	  to	  be	  represented	  individually	  or	  act	  independently.	  Collectively,	  the	  FFA	  works	   to	   protect	   present	   and	   future	   rights	   to	   sustainable	   tuna	   fishing,	   as	  well	   as	   fair	  economic	   and	   social	   benefits	   for	   people	   in	   the	   region	   (particularly	   for	   small	   island	  states).	  However,	  more	  effort	  needs	  to	  come	  from	  larger	  fishing	  countries,	  particularly	  those	  with	  extensive	  distant-­‐water	  fleets	  and	  substantial	  imports	  (e.g.,	  Japan,	  Taiwan).	  	  8 Current	   member	   nations	   and	   countries	   of	   the	   FFA:	   Australia,	   Cook	   Islands,	   Federated	   States	   of	  Micronesia,	  Fiji,	  Kiribati,	  Marshall	   Islands,	  Nauru,	  New	  Zealand,	  Niue,	  Palau,	  Papua	  New	  Guinea,	  Samoa,	  Solomon	  Islands,	  Tokelau,	  Tonga,	  Tuvalu	  and	  Vanuatu.	  	   115	  	   As	   discussed	   in	   the	   Introduction,	   bluefin	   tuna	   is	   the	   epitome	   of	   a	   luxury	   fish.	  Currently,	   both	   southern	   and	  Pacific	   bluefin	   are	  overfished,	  with	   the	   former	  being	  on	  classified	   as	   ‘Critically	   Endangered’	   by	   the	   IUCN	   (Collette	   et	   al.	   2011).	   Thus,	   these	  species	   represent	   a	   model	   case	   for	   such	   international	   conservation	   collaboration	   to	  occur.	   Pacific	   bluefin	   is	   fished	   almost	   exclusively	   by	   Japan,	   with	   Japan	   importing	  approximately	  90%	  of	  Korea’s	  Pacific	  bluefin	  catch	  as	  well	  (WCPFC	  2010).	  Unfortunately,	  the	  majority	  of	  this	  catch	  consists	  of	  juvenile	  (i.e.,	  immature)	  fish	  (ISC	  2013c).	  Therefore,	  Japan	   has	   an	   opportunity	   to	   play	   a	   significant	   role	   in	   decreasing	   both	   the	   amount	   of	  underage	  Pacific	  bluefin	  caught	  and	  limiting	  the	  amount	  that	  is	  imported	  and	  sold.	  	   A	   different	   problem	   with	   similar	   consequences	   exists	   for	   southern	   bluefin:	  ‘capture-­‐based	   aquaculture’.	  While	   Japan	   controls	   the	  majority	   of	   longline	   fishing	   for	  southern	   bluefin,	   Australia’s	   quasi-­‐aquaculture	   industry	   exports	   the	   majority	   of	   the	  ranched	  bluefin	  to	  Japan	  (Patterson	  et	  al.	  2012).	  These	  operations	  use	  purse	  seines	  to	  capture	   immature	   southern	   bluefin,	   which	   are	   subsequently	   brought	   to	   large	   ocean	  pens	  where	  they	  are	  fed	  for	  several	  months.	  Once	  plumped	  up,	  these	  tuna	  are	  killed	  and	  shipped	  abroad	  where	  they	  will	   feed	  a	  much	  smaller	  demographic	  that	   is	  the	  wealthy,	  developed	  world	  clientele.	  If	  these	  fish	  had	  been	  caught	  and	  exported	  immediately,	  they	  would	   be	   worth	   about	   AU$	   40	   million	   annually.	   However,	   post-­‐ranching,	   these	   fish	  garner	  upward	  of	  AU$	  150	  million	  instead	  (Patterson	  et	  al.	  2012).	  	  	   While	   tuna	   ranching	   impacts	   a	   stock	   in	   the	   same	   way	   as	   catching	   immature	  Pacific	  bluefin	  does	  (since	  captive	  individuals	  are	  under-­‐age	  and	  will	  never	  contribute	  to	  the	   breeding	   stock)	   (Ottolenghi	   2008b),	   it	   also	   impacts	   other	   fish	   populations	   from	  116	  which	   forage	   fish	   are	   obtained	   to	   feed	   the	   tuna	   (Volpe	   2005).	   Since	   tuna	   are	   active	  piscivores,	   they	   require	   large	   amounts	   of	   protein	   to	   maintain	   their	   daily	   energy	  requirements	   and	   grow.	   In	   terms	   of	   aquaculture,	   the	   food	   conversion	   ratio	   (FCR)9	  for	  bluefin	   is	   the	   highest	   among	   all	   fish,	   and	   can	   be	   as	   high	   as	   30	   (Aguado-­‐Gimènez	   and	  Garcìa-­‐Garcìa	   2005).	   Therefore,	   although	   people	   in	   coastal	   communities	   in	   countries	  such	  as	  Peru	  and	  Chile	  rely	  on	  smaller	  fish	  species	  (e.g.,	  sardines,	  capelin,	  pilchards)	  as	  a	  primary	  source	  of	  protein,	  these	  forage	  fish	  are	  often	  sold	  for	  a	  higher	  profit	  to	  ranching	  companies	  abroad.	  Thus,	  despite	  being	  a	  lucrative	  industry	  and	  a	  valuable	  component	  of	  Australia’s	   natural	   resource	   economy,	   this	   type	   of	   aquaculture	   is	   detrimental	   to	   both	  the	   local	  environment	   (i.e.,	   southern	  bluefin	  population)	  as	  well	  as	  at	  a	  much	  broader	  scale.	  Although	  some	  companies	  have	  started	  to	  use	  primarily	  locally	  caught	  sardines	  to	  feed	  their	  captive	  bluefin10,	  Australia	  should	  take	  a	   lead	   in	  dramatically	   improving	  and	  restructuring	  the	  entire	  operation	  to	  be	  a	  more	  sustainable	  endeavour.	  	  Beyond	  the	  concentrated	  issues	  surrounding	  the	  two	  bluefin	  spec