UBC Faculty Research and Publications

Bycatches in fisheries and their impact on the ecosystem Pitcher, Tony J.; Chuenpagdee, Ratana 1994

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
52383-FCRR_1994_2-1.pdf [ 41.42MB ]
Metadata
JSON: 52383-1.0074770.json
JSON-LD: 52383-1.0074770-ld.json
RDF/XML (Pretty): 52383-1.0074770-rdf.xml
RDF/JSON: 52383-1.0074770-rdf.json
Turtle: 52383-1.0074770-turtle.txt
N-Triples: 52383-1.0074770-rdf-ntriples.txt
Original Record: 52383-1.0074770-source.json
Full Text
52383-1.0074770-fulltext.txt
Citation
52383-1.0074770.ris

Full Text

I S S N 1 1 9 8 - 6 7 2 7 Fisheries Centre Research Reports 1994 Volume 2 Number 1 Bycatches in Fisheries and their Impact on the Ecosystem Fisheries Centre, University of British Columbia, Canada edited by Prof. Tony J. Pitcher and Rattana (Ying) Chuenpagdee published by The Fisheries Centre, University of British Columbia 2204 Main Mall Vancouver, B.C., Canada ISSN 1198-6727 TABLE OF CONTENTS Director's Foreword Tony J.Pitcher ..1 Workshop Agenda 3 Section I: Ecological and Economic Impact of Bycatches on Fisheries Session Summary Peter Larkin 5 The bycatch problem from an economic perspective Joe Terry 6 Bycatch mortality impacts and control for Pacific halibut Bruce Leaman. 14 Three proposed solutions to bycatch and discard in the North Pacific: focus on the U.S. rocksole fishery John Gauvin and Joe Blum .23 Section II: Bycatches and Trawl Fisheries The Pacific groundfish trawl fisheries: bycatch problem and potential solutions Barry Ackerman 31 Research and development efforts in bycatch elimination in trawl fisheries of British Columbia Douglas March 31 Development of by-catch reducing trawl gears in NSW's prawn trawl fisheries Steven Kennelly 33 Use of a semi-pelagic trawl in a tropical demersal trawl fishery David Ramm ..39 Section III: Bycatches and Passive Gear Fisheries World bycatches of sharks in high-seas fisheries: appraising the waste of a resource Ramon Bonfil 41 Management of bycatch in hook-and-line groundfish fisheries off Alaska Janet Smoker 45 Bycatch of steelhead (Oncorhynchus mykiss) and coho (O. kisutch) in the Skeena river sockeye (O. nerka) fishery Joel Sawada and Art Tautz 49 Section IV: Bycatches and Purse-seine Fisheries Bycatches in purse-seine fisheries Martin Hall. 53 By catch in B.C. purse-seine fisheries: recent experiences in south coast chum salmon fisheries Paul Ryall 59 Reducing by catch through gear modifications: the experience of the tuna-dolphin fishery Harold Medina 60 Section V: Towards solving the bycatch problem Bycatch strategies: some success stories and promising approaches Brad Warren 61 A classification of bycatch problems and some approaches to their solutions Martin Hall. 65 Section 6: Summary of working groups Technology Steve Kennelly 75 Policy and Attitudes Andrew Trites 78 List of Participants 79 Fisheries Centre Workshop Series 85 1 DIRECTOR'S FOREWORD Academic fishery researchers, fisheries graduate students, government fishery scientists, fisheries consultants and a commercial fishermen gathered at the Fisheries Centre at UBC on October 13th and 14th 1994 in order to discuss the problems of by-catch. 51 participants came from British Columbia, Washington, Alaska, California, Mexico and Australia. This comprises the 3rd report in the UBC Fisheries Centre's Research Report Series. There is little doubt that, for conventional fisheries and the existing spectrum of species, the sustainable marine world fish catch has reached its limits of around 80 million tonnes per annum. It is not surprising therefore that we hear growing public concern at the amount of discarded by-catch in world fisheries, currently estimated at around 30%. That one tonne offish in every three caught is tipped back into the sea is perceived as a waste of fish and of fishing activity in a world short of protein for human nutrition and rife with demands for economic development. Conservation groups focus on such iniquities as evidence of irresponsible fishing driven by greed, multinational corporations and evil fisher folk. To make matters worse, mortality of marine mammals and turtles as by-catch in commercial fisheries enrages conservation groups and large sectors of the general public. TTiis workshop was held to establish some of the facts about by-catch, discuss how its adverse effects might be mitigated, and try to determine whether the different perspectives of the fishing industry, fish ecologists, conservationists and policy makers on this issue might be reconciled. Discards are large and widespread in tropical fisheries for high value species like prawns, where in the worst examples in South East Asia as much as ten tonnes of small fish are discarded for every tonne of prawns landed. Fish that are caught below legal size limits of target species are commonly discarded, for example in purse seine fisheries for mackerel in Europe, a practice known as 'high- grading* (Figure 1). It is a surprise and a paradox that large by-catch illegal catch target species non-targel ?vspecicsj discards impact on stocks and ecosystem FISH STOCKS ?. . . alive TOTAL MORTALITY high--grading Figure By-catch: by Hook and by Crook 2 discards are endemic in many intensively researched and managed fisheries in North America, and that these discards occur as a direct consequence of complex and well-considered regulations supporting policies devised to avoid depletion. Operational reduction of bycatch through more careful fishing practice, in tandem with incentives to vessel skippers and crew, is one development presented here that has significantly reduced bycatch in tuna fisheries. Technical solutions may be found lie in the improvement of gear design to allow target species to escape the gear and survive but this simple objective often turns out to be not as simple as might be thought. Figure 1 illustrates schematically what happens when fish encounter fishing gear. Fish make a series of behavioural decisions that result in evasion, escape or capture. Most fishing gears have traditionally been designed to maximise capture, and so the technical challenge in reducing bycatch is to identify key behavioural components of this system that may selectively release or allow the escape of fish that are too small or of the wrong species. Several solutions of this kind were presented at the workshop. Nevertheless, even with technical advances in the design of fishing gear, some bycatch is inevitable, and at the workshop there was discussion of the idea that we have to learn to accept that trade-offs have to be made, even with marine mammal deaths, if fisheries are to be managed optimally and sustainably. An analysis of bycatch may distinguish ecological, technological, economic and policy determinants, with consequences and candidate remedies that may be associated with each of these categories. This report commences with a section devoted to a review of ecological and economic factors, followed by reports on two important North Pacific fisheries. Subsequent sections then discuss bycatch in three different types of fishing gear: trawls, purse seines and passive gear such as long-lines. Technical development of selective trawl and purse seine gears is evaluated and case studies presented from Australia, British Columbia, Alaska and Mexico. There is also a review of by-catch problems affecting world shark populations. Section 5 presents progress towards a general classification and strategies for solving bycatch problems, while the final section comprises summaries of the discussions on ecological and economic impacts, technological solutions and policy and attitudes to bycatch that were presented following discussions among three working groups at the workshop. In contrast to the atmosphere of gloom and foreboding that seems obligatory at many workshops on fisheries problems these days, most of the participants were generally more optimistic at the end of the workshop than at the beginning. Hopefully, this was not just on account of the convivial atmosphere that is associated with Fisheries Centre workshops, and is a portent of reasonable solutions may soon be devised to the bycatch problem. Tony J. Pitcher Director, Fisheries Centre UBC, Vancouver 3 WORKSHOP AGENDA 13 October 1994 8:15- 8:45 Registration & Continental Breakfast 8:45 - 9:00 Welcoming and Opening Address Bycatch in Fisheries: By Hook and By Crook Tony Pitcher, UBC Fisheries Centre Session 1: Ecological and Economic Impact of Bycatches on Fisheries 9:00 - 9:10 General Introduction Peter Larkin, UBC, North Pacific Universities Marine Mammal Research Consortium 9:10 - 9:30 The bycatch problem from an economic perspective Joe Terry, NMFS, Washington 9:30 - 9:50 Bycatch mortality impacts and control for Pacific halibut Bruce Leaman, PBS, Nanaimo 9:50 - 10:10 Three proposed solutions to bycatch and discard in the North Pacific: focus on the U.S rocksole fishery John Gauvin and Joe Blum, American Factory Trawler Association 10:10-10:30 Coffee Break Session 2: Bycatches and Trawl Fisheries 10:30-10:40 General Introduction Dayton L. Alverson, Natural Resources Consultants, Inc., Washington 10:40-11:00 The Pacific groundfish trawl fisheries: bycatch problem and potential solutions Barry A ckerman, DFO 11:00-11:20 Research and development efforts in bycatch elimination in trawl fisheries of British Columbia Douglas March, Deep Sea Trawlers Association of B.C. 11:20-l 1:40 Development of by-catch reducing trawl gears in NSW's prawn trawl fisheries Steven Kennelly, NSW Fisheries, Australia 11:40-12:00 Use of a semi-pelagic trawl in a tropical demersal trawl fishery David Ramm, Dept. of Primary Industry and Fisheries, Darwin, Australia 12:00 - 1:00 Sandwich lunch (in RalfYorque Room) Session 3: Bycatches and Passive Gear Fisheries 1:00 - 1:10 General Introduction Andrew Trites, UBC, North Pacific Universities Marine Mammal Research Consortium 1:10 - 1:30 World bycatches of sharks in high-seas fisheries: appraising the waste of a resource Ramon Bonfil, UBC Fisheries Centre 1:30 - 1:50 Management of bycatch in hook-and-line groundfish fisheries off Alaska Janet Smoker, Fisheries Info. Service 1:50 - 2:10 Bycatch of steelhead (Oncorhynchus mykiss) and coho (O. kisutchfm the Skeena river sockeye (O. nerka) fishery Joel Sawada and Art Tautz, B.C. Provincial Fisheries Branch 4 Session 4: Bycatches and Purse-seine Fisheries 2:10 - 2:20 General Introduction Martin Hall, Inter-American Tropical Tuna Commission 2:20 - 2:40 Bycatches in purse-seine fisheries Martin Hall, Inter-Americcm Tropical Tuna Commission 2:40 - 3:00 Bycatch in B.C. purse-seine fisheries: recent experiences in south coast chum salmon fisheries Paul Ryall, DFO 3:00 - 3:20 Coffee Break 3:20 - 3:40 Reducing bycatch through gear modifications: the experience of the tuna-dolphin fishery Harold Medina, California 3:40 - 4:00 Bycatch strategies: some success stories and promising approaches Brad Warren, National Fisherman, Washington 4:00 - 4:20 A classification of bycatch problems and some approaches to their solutions Martin Hall, Inter-American Tropical Tuna Commission 4:20 - 5:30 Summary of Day One {identification of major issues to be addressed on Day Two) 14 October 1994 9:00 - 12:00 Parallel sessions of working groups, addressing major issues identified on Day One. 12:00 - 1:00 Sandwich lunch (in Ralf Yorque Room) 1:00 - 2:00 Chair of each working groups report to the full meeting 2:00 - 4:00 Full meeting discussion and summary / Discussion of possible publication. 4:00 Adjourn SECTION ECOLOGICAL AND ECONOMIC IMPACT OF BYCATCHES ON FISHERIES 5 SESSION SUMMARY: ECOLOGICAL AND ECONOMIC IMPACT OF BYCATCHES ON FISHERIES Peter Larkin, North Pacific Universities Marine Mammal Research Consortium, Room 18, Hut B-3,6248 Biological Sciences Road, Vancouver, B.C. V6T 1Z4, Canada. ? ? ? Because fisheries management has focused on statistics of landings the effect of bycatches on marine ecosystems and on the economics of fisheries operations has not been given sufficient attention. It has been estimated by Alverson et al (1994) that the world marine fisheries catch of 83 million tonnes may be 30% less than actual catch. The ecological effects include mortality of discards of undersize, wrong sex or otherwise unwanted individuals of target species, incidental mortality to desired but non-target species, ready availability of food to scavenging species, and differential effects on the interactions between species in fish communities with possible rever-berations through community structure. Economic issues include the loss of time in sorting the catch, the costs of selective gear or restrictions on time and area of fishing, the costs of retaining the bycatch and its value if landed. The economic perspective on bycatch was suc-cinctly presented by Joseph Terry of the Alaska Fisheries Science Centre. Bycatch is an econ-omic problem "if it precludes other higher valued uses" and "if there are costs associated with actions to reduce bycatch". His analysis related the marginal costs and benefits to the level of bycatch mortality from the perspectives of the individual fisher and of society. The ecological impacts are not readily quantified in economic terms. Bruce Leaman described the bycatch problem of the trawl fisheries of Alaska and British Colum-bia with particular reference to the bycatch of halibut. The market for the bycatch of many species and sizes is limited. For valued species such as halibut, quotas or trip limits pose prob-lems of monitoring and enforcement. Ecological impacts are not readily assessed because there is no routine monitoring of abundance of non-target species. The relative abundance of target and non-target species is important in determining the severity of the bycatch problem. John Gauvin and Joe Blum presented solutions to the rock sole bycatch problem in the Gulf of Alaska: increasing mesh size, increasing reten-tion rates, establishment of individual transfer-able quotas (ITQs) with tradeable rights to bycatch. The measures would reduce the bycatch from a fishery that targets on females with roe. Discussion was combined with that of session two and underlined the uncertain nature of ecological impacts. Except for historical data on fisheries recently developed there is little infor-mation on pristine relative abundance of species. Changes in abundance of non-target species may be available from research cruises but the selec-tivity of gear makes even these data unreliable indices. The view was unanimous that greater attention should be given to bycatch issues if management is to take better account of the ecological and economic issues involved. 6 THE BYCATCH PROBLEM FROM AN ECONOMIC PERSPECTIVE Joseph M. Terry, Alaska Fisheries Science Center, National Marine Fisheries Service. NOAA F/AK C2, 7600 Sand Point Way NE? Seattle, WA 98115, USA ABSTRACT Bycatch occurs whenever fishing gear is not perfectly selective. Bycatch is a problem if it precludes higher valued uses of fish and other living marine resources and if there are costs associated with actions to reduce bycatch. If the former condition is not met, there is not a prob-lem. If the latter condition is not met, the solution to the problem is trivial. There are two related issues that should be considered in deter-mining how to control bycatch. They can be stated in terms of the following two-part ques-tion. What are the appropriate levels of bycatch and why are those levels being exceeded? Both the benefits and costs of decreasing bycatch are important in determining the answer to each part of this question, in comparing the extent of the bycatch problem among fisheries, and in evaluat-ing fishery management alternatives intended to address the bycatch problem. This paper is based on a three part series of discussion papers on proposals currently under consideration by the North Pacific Fishery Management Council to address the problems of bycatch, discard, and the utilization of catch in the groundfish fisheries off Alaska. ? ? ? The objective for fishery management is to increase the contribution of fishery resources to the well-being of the Nation. This can be done by increasing the total net benefit resulting from the use of fishery resources and by improving its intra-temporal and inter-temporal distributions. The uses of these resources are not limited to direct consumptive uses by man. In the case of a stock of fish, the uses include being taken as catch and bycatch in a variety of fisheries and for a variety of purposes, providing prey for other living marine resources, acting as pred-ators, and contributing to the future size of that stock of fish. The net benefit to the Nation is equal to the difference between the total benefit (value) of the outputs and the total cost (value) of the inputs associated with the uses of fishery resources. Costs and benefits should be defined broadly from the Nation's perspective to include those that accrue to direct and indirect participants in the fishery as well as to other members of society. The inputs used in a commercial fishery include fish taken as target catch and bycatch; other living marine resources; the fishing vessels, gear, and bait used in harvesting; the plants or vessels, equipment, and materials used for processing; and the fuel and labor used through-out the production process. The cost of each input should be measured in terms of its oppor-tunity cost which is the net benefit foregone in its highest valued alternative use. Because each use of a fishery resource is associated with a different combination of inputs and outputs, alternative uses cannot be ranked in terms of net benefits without considering the values to the Nation of all the inputs and all the outputs of each use. The net benefit of the use of fish in a commer-cial fishery and its distribution are determined jointly by the answers to the following four questions: 1. How much fish is removed each year by the fishery? 2. How is it removed? 3. By whom is it removed? 4. For what purposes is it removed? The answers to these questions are determined by the decisions made by individual fishermen and processors in response to a variety of incen-tives and constraints that reflect the economic, social, regulatory, biological, and physical environments in which they operate. Each of these four questions is intended to encompass a range of questions. The first question addresses not only total removals but also the size, age, sex, temporal, and spacial distributions of the removals. The second question addresses the cost of all the inputs associated with a particular method of harvesting fish. The third question is intended principally to address a range of distribution questions. The fourth question addresses both the cost of all the inputs associated with the use of catch and the benefits of those uses. The amount offish removed (used) by fishermen is total fishing mortality. In addition to fishing mortality accounted for by retained catch, it includes the fishing mortality resulting from the following: discarded catch; lost gear; and other direct interactions of fish with fishermen , fishing vessels, or their gear. Often it is difficult to obtain good estimates for the removals accounted for by retained catch and even more difficult to do so for the other components of fishing mor-tality. The at-sea and on-shore observer program and product weight monitoring program for the Bering Sea/Aleutian Islands (BSAI) and Gulf of Alaska (GOA) groundfish fisheries in the US EEZ provide better estimates of catch, bycatch, discards, and the use of retained catch and bycatch for these two fisheries than are available for most other fisheries. Although the bycatch rates vary significantly among individual compo-nents of these two fisheries, the overall bycatch rates in these two fisheries are not high com-pared to those in many fisheries. However, these rates result in levels of bycatch that are high compared to those in many fisheries due to the sheer magnitude of the BSAI and GOA groundfish fisheries. In 1993, estimated total groundfish catch in the BSAI and GOA groundfish fisheries was about 2,148,000 metric tons (t) and estimated groundfish discards were 348,000 t for an average discard rate of .16.2% (Table 1). For the BSAI fisheries, the 1993 discard rates ranged from 4.5% in the pelagic pollock trawl fishery (Table 2) to 69% in the rock sole trawl fishery (Table 3). In response to concerns about the levels of bycatch in the BSAI and GOA fisheries, the North Pacific Fishery Management Council (Council) has recommended and the Secretary of Commerce has approved and implemented a variety of management actions that were intended principally to control the bycatch of halibut, crab, herring, and salmon in the groundfish fisheries. Recently, the bycatch of groundfish and the utilization of the catch and bycatch of groundfish have received increased attention as has the bycatch of crab in the BSAI crab fisheries. There are two related issues that should be considered in determining how to control bycatch. They can be stated in terms of the following questions: What is the appropriate level of bycatch? 2 Why are there currently excessive levels of bycatch? Each question is answered below. What is the appropriate level of bycatch? A common response to this question is that no bycatch is the appropriate level. Some modify this response to say that the lowest level of bycatch practicable is appropriate. This modifi-cation recognizes that it may not be technologi-cally possible to eliminate all bycatch without eliminating some very important fisheries. This modification is a step in the right direction. However, unless the definition of "practicable" is extended to consider the costs, as well as the benefits, of decreasing bycatch, that response is also incorrect in terms of increasing the net benefit to the Nation from using fishery resources. Basically, it makes sense to reduce bycatch in a cost effective manner to the level at which further changes would increase costs more than they would increase benefits. If cost effec-tive methods are not used to decrease bycatch, the point at which the additional costs exceed the additional benefits will be reached at a higher level of bycatch. The marginal benefit and marginal cost curves in Figure 1 present graphically the concept of the optimum level of bycatch. The marginal benefit curve depicts the marginal (or additional) benefit of reducing bycatch mortality by one more unit. Similarly, the marginal cost curve depicts the marginal (or additional) cost of reducing bycatch mortality by one more unit. When there are high levels of bycatch and little has been done to control bycatch, there are probably some simple and low cost actions that can be taken to reduce bycatch. However, at some point, the simple and low cost methods of reducing bycatch will be exhausted and more difficult and costly actions would be necessary and extreme 8 measures may be necessary to eliminate the last few units of bycatch. Therefore, the marginal cost curve is expected to slope down to the right. The marginal benefit curve is expected to slope up to the right for the following reasons. At very low levels of bycatch, most of the fishing mortality of the species taken as bycatch is accounted for by other fisheries and the net benefit of some of the uses of that species in those other fisheries probably is quite low. However, at very high levels of bycatch, much of the fishing mortality of that species is accounted for by the bycatch and the lower valued uses in other fisheries would have been eliminated. As a result, the opportunity cost of a unit of bycatch which is the marginal benefit of reducing bycatch would be high. If the marginal benefit and cost curves capture all benefits and costs to the Nation, the appropri-ate level of bycatch is that at which the marginal cost and marginal benefit are equal. In this example, marginal cost and marginal benefit both equal $10 when bycatch equals 10,000. At lower levels of bycatch, the marginal cost of reducing bycatch is greater than $10 and the marginal benefit is less than $10; therefore, reducing bycatch below 10,000 units would decrease net benefit. However, at higher levels of bycatch, the marginal cost is less than $10 and the marginal benefit is greater than $10; therefore, net benefit would be increased by decreasing bycatch. The implications of not using cost effective methods of controlling bycatch are depicted in Figure 2. MCI and MC2, respectively, are the marginal cost curves when cost effective methods are uses and when they are not used. The appropriate level of bycatch is 10,000 units when the cost effective methods are used, but it is 15,000 units when MC2 is the marginal cost curve because cost effective methods are not used. Why are there currently excessive levels of bycatch? A common response to this question is that the greed or lack of concern by the fisher-men who make decisions on when and how to fish results in excessive bycatch. Perhaps a more thoughtful and productive response is that excessive bycatch is but one of the symptoms of a major flaw in the way many fisheries are managed. Experience and economic theory demonstrate that, in an open access fishery, each fisherman has incentives to make decisions that result in the wrong answers to the four questions that jointly determine the level and distribution of the net benefit generated by a commercial fishery. Generally, too much fish will be removed and, due to the answers to the last three questions, the cost of inputs will be unnecessar-ily high and the value of outputs (benefit) will be unnecessarily low for each given level of removals. The source of the problem principally is that in making decisions each fisherman is motivated by his expectations concerning the benefit he will receive and the cost he will bear but his deci-sions can result in benefits and costs for others. These externalities (i.e., benefits and costs that are to some extent external to the fisherman and his decision making process) result in individual fishermen making decisions that collectively decrease the net benefit generated from the use of fishery resources. The source of the problem is depicted in Figure 3 in which MBF and MBS, respectively, are the marginal benefits curves for a fisherman and for society at large including the fisherman. From the fisherman's perspective, it makes sense for him to control bycatch up to the point at which his marginal benefit and marginal cost of reduc-ing bycatch are equal. In this example, MBF and MC are equal when bycatch is 200. Because the marginal benefit curve for society (MBS) includes the marginal benefit to the fisherman and to the rest of society and because the rest of society also benefits from a reduction in bycatch, MBS is above MBF and the optimum level of bycatch for that fisherman from society's perspective is only 150. The external benefit results in the fisherman taking too much bycatch. The concept of the optimum level of bycatch as presented above is quite simple. Applying the concept can be very difficult due to the difficulty in determining all of the benefits and costs of decreasing bycatch. As noted above, the direct benefit of decreasing bycatch is the decrease in the total opportunity cost of using fish as bycatch and the opportunity cost of a use of fish equals the net benefit foregone in its highest valued 9 alternative use. The alternative uses include: (1) catch in another commercial fishery; (2) consumptive uses in subsistence and recreational fisheries; (3) contributions to the stock and other sectors of die ecosystem, some of which are non-consumptive uses; and (4) other non-con-sumptive uses. The value of the fourth includes existence and option values. Fortunately, many of the species that are the focus of concern are taken as target catch in commercial fisheries. If it is determined that the use of a specific species as retained catch with adequate utilization is an appropriate use of fish of that species, there is an implicit determination that the value of that use is at least as high as the value of any use other than in a commercial fishery. If this were not the case, that use would not be appropriate and it should be eliminated. Therefore, the opportunity cost of using such a species as bycatch is at most the foregone net value of the use that was determined to be appropriate. If the use of a species for bycatch does not result in foregone catch for that accept-able use, the per unit opportunity cost may be less than the net benefit per unit of acceptable use. For the living marine resources that are not used commercial but that are inputs for a fishery, opportunity costs would have to be estimated based on their expected values in other uses such as their contribution to the value of the ecosys-tem. Such valuations are difficult. The mar-ginal contribution can be positive or negative and we may not know which it is without a substan-tially increased understanding of the ecosystem. Information on the magnitude of bycatch relative to the biomass of such species may indicate whether bycatch is expected to have a significant effect on the contribution of such species to the value of the ecosystem. The valuation of the opportunity cost of these non-commercial species is important when different management policies are expected to result in significantly different levels of use of these resources (inputs). The cost of decreasing bycatch can be equally difficult to predict accurately. The range, effectiveness, and cost of changes in fishing strategies that would decrease bycatch are not known by the fishery managers. Part of the uncertainty concerning the cost of reducing the bycatch of one species occurs because bycatch is a multi-species problem in which actions to reduce the bycatch of one species often increase the bycatch of other species. The problems of predicting the costs and benefits of regulatory actions to control bycatch make it difficult to evaluate either the net National benefits of proposed regulatory changes or the distributions of the changes in net benefits. However, these problems do not eliminate the rational for attempting to consider both the benefits and costs of actions to decrease bycatch and to use cost effective methods. The concept-ual framework for determining the optimum level of bycatch and for understanding why regulatory intervention is necessary are useful in evaluating bycatch management alternatives even when accurate estimates and projections of all costs and benefits are not feasible. Bycatch is a problem when it results in a lower valued use of a fishery resource. Eliminating that use is one solution and increasing the value of that use is another. The appropriate mix of these two solutions will depend on the marginal benefits and costs of decreasing bycatch and of increasing the value of bycatch. The benefits and costs of decreasing bycatch also are important in comparing the extent of the bycatch problem among fisheries. Although bycatch is typically measured in terms of physi-cal units, such as weight or numbers of animals, aggregate physical measures of bycatch often are of limited use and frequently are misleading. The problem is that the importance or value of bycatch per physical unit can vary significantly by species, size, sex, season, and area. Because an aggregate physical measure of bycatch does not account for such differences, it is not useful in comparing bycatch among fisheries for which there are differences in either the ecological or economic value per unit of bycatch within or among fisheries. A value based measure of bycatch, such as the opportunity cost of using fishery resources as bycatch, would provide a substantially more useful measure if both eco-logical and economic relationships are reflected adequately in the estimates of the opportunity cost of bycatch. With respect to proving mean-ingful comparisons among fisheries, even limited attempts to account for differences in the oppor-tunity cost per physical unit of bycatch could result in a substantial improvement compared to strictly physical aggregate measures of bycatch. Such measures would provide estimates of the benefits of decreasing bycatch. To compare the potential net benefits among fisheries of reducing bycatch, the cost of reducing bycatch also has to be considered by fishery. Table 1 Estimated groundfish catch and discards (1,000 metric tons) in the BSAI and GOA groundfish fisheries, 1 9 9 1 -1994. BSAI 1991 1992 1993 1994 Catch 2,127 1,996 1,887 1,140 Discards 285 316 296 187 % Discarded 13.4 15.8 15.7 16.4 GOA 1991 1992 1993 1994 Catch 260 284 261 181 Discards 36 61 52 24 % Discarded 13.8 21.4 19.9 13.0 BSAI and GOA 1991 1992 1993 1994 Catch 2,387 2,280 2,148 1,321 Discards 321 377 348 211 % Discarded 13.4 16.5 16.2 16.0 Note: The discard rate estimates that were calculated using unrounded estimates of catch and discards cannot all be reproduced exactly using the data provided in this table. Source: NMFS Alaska Region blend estimates through July 15, 1994. 11 Table 2 Groundfish catch and discards in the BSAI pelagic pollock trawl fishery, 1991-1994* Total catch Metric tons Species composition 1991 Pollock 680,902 99.2% Pacific cod 3,019 .4* Sablefish 2 .0% Turbot 63 .0% Rock sole 207 .0% Yellowfin 39 .0% Arrowtooth 456 .1% Flat other S56 .1% Rockfish 68 .0% Atka mack 0 .0% Other 878 .1* Total 686,490 100.0% 1992 Pollock 1. 295,707 97.7% Pacific cod 13,492 1.0% Sablefish 8 .0% Turbot 251 .0% Rock sole 3,268 .2% Yellowfin 186 .0% Arrowtooth 2,798 .2% Flat other 5,629 .4% Rockfish 205 .0% Atka mack 242 .0% Other 4,159 .3% Total 1, 325,944 100.0% 1993 Pollock 1. 227,495 98.6% Pacific cod 8,648 .7% Sablefish 0 .0% Turbot 67 .0% Rock sole 2,089 .2% Xellowfin 579 .0% Arrowtooth 557 .0% Flat other 2,659 .2% Rockfish 234 .0% Atka mack 35 .0% Other 2,346 .2% Total 1, 244,710 100.0% 1994* Pollock 1, 135,024 99.0% Pacific cod 3,230 .7% Sablefish 2 .0% Turbot ? 55 .0% Rock sole 333 .0% Yellowfin 147 .0% Arrowtooth 956 .1% riat other 1,457 .1% Rockfish 91 .0% Atka mack 61 .0% Other 713 .1% Total 1, 197,078 100.0% ! Discarded catch Metric tons Species Discard composition rate 50,216 92.4% 7.4% 1,806 3.3% 59.8% 2 .0% 96.8% 59 .1% 93.8% 184 .3% 88.7% 31 .1% 79.6% 398 .7% 87.2% . 754 1.4% 88.1% 52 .1% 76.9% 0 .0% 95.8% 627 1.5% 94.2% 54,330 100.0% 7.9% 80,653 77.2% 6.2% 8,658 8.3% 64.2% 4 .0% 54.8% 187 .2% 74.4% 3,061 2.9% 93.7% 176 .2% 94.7% 2,635 2.5% 94.2% 5,068 4.8% 90.0% 180 .2% 87.6% 219 .2% 90.5% 3,695 3.5% 88.8% 104,536 100.0% 7.9% 41,359 73.0% 3.4% 7,052 12.5% 81.5% 0 .0% 15.9% 66 .1% 99.6% 2,068 3.7% 99.0% 556 1.0% 96.0% 497 .9% 89.2% 2,508 4.4% 94.3% 227 .4% 96.9% 34 .1% 98.0% 2,252 4.0% 96.0% 56,619 100.0% 4.5% 20,774 72.7% 1.8% 4,906 17.2% 59.6% 1 .0% 37.6% 64 .2% 99.6% 293 1.0% 33.2% 125 .4% 85.6% 834 2.9% 87.3% 879 3.1% 60.3% 61 .2% 66.8% 58 .2% 94.2% 553 2.0% 78.9% 28,553 100.0% 2.4% Source: NMFS Alaska Region blend estimates through Oct 29, 1994. 12 Table 3 Croundfish catch and discards in the BSAI rock sole trawl fishery, 1991-1994* Metric tons Species Metric tons Species Discard composition composition rate 1991 Pollock 9,699 22.7% 8,735 32.4% 90.1% Pacific cod 4,258 10.0% 1,652 6.1% 38.8% Sablefish 9 .0% 9 .0% 100.0% Turbot 1 .0% 1 .0% 100.0% Rock sole 22,038 51.7% 11,120 41.2% 50.5% Tellowfin 2,040 4.8% 1,495 5.5% 73.3% Arrowtooth 254 .6% 254 .9% 100.0% Flat other 2,606 6.1% 2,076 7.7% 79.7% Rockfish 46 .1% 1 .0% 1.9% Atka mack 3 .0% 3 .0% 100.0% Other 1,692 4.0% .1,651 6.1% 97.6% Total 42,646 100.0% 26,998 100.0% 63.3% 1992 Pollock 10,339 19.4% 9,491 27.8% 91.8% Pacific cod 4,805 9.0% 2,108 6.2% 43.9% Sablefish 0 .0% - - -Turbot 3 .0% - - ? Rock sole 24,866 46.6% 12,194 35.7% 49.0% Yellowfin 4,848 9.1% 2,977 8.7% 61.4% Arrowtooth 630 1.2% 628 1.8% 99.7% Flat other 4,727 8.9% 3,620 10.6% 76.6% Rockfish 22 .0% 22 .1% 97.7% Atka mack 10 .0% 3 .0% 32.3% Other 3,133 5.9% 3,107 9.1% 99.2% Total 53,384 100.0% 34,150 100.0% 64.0% 1993 Pollock 18,573 22.0% 17,321 29.7% 93.3% Pacific cod 8,160 9.7% 5,632 9.7% 69.0% Sablefish 4 .0% 3 .0% 68.2% Turbot 28 .0% 26 .0% 92.9% Rock sole 39,857 47.2% 23,283 39.9% 58.4% Yellowfin 6,277 7.4% 3,799 6.5% 60.5% Arrowtooth 1,144 1.4% 1,143 2.0% 100.0% Flat other 7,270 8.6% 4,031 6.9% 55.4% Rockfish 21 .0% 18 .0% 89.8% Atka mack 15 .0% 8 .0% 53.7% Other 3,091 3.7% 3,030 5.2% 98.0% Total 84/439 100.0% 58,295 100.0% 69.0% 1994* 94.2% Pollock 16,077 20.6% 15,139 27.3% Pacific cod 6,271 3.0% 3,832 7.1% 61.9% Sablefish 16 .0% 2 .0% 12.3% Turbot 50 .1% 39 . 1% 73.3% Reek sole 40,413 51.7% 23,So4 43.5% S3. 5% Yeilowfin 4,809 6.2* 3,546 5.5% 73.7% Arrowtooth 1,744 2.2% 1,744 3.2% 1CC.0% Flat other 5,488 7.0% 3,125 5.7% .57.0% Rockfish 12S .2% 115 .2% 92. 3% Atka mack 0 .0% - -Other 3,162 4.0% 3,119 5.7% 93.6% Total 78,161 100.0% 54,377 100.0% 69.6% Seurre NM?S Alaska Region blend estimates through Oct 29 1994 Marginal Coat Marginal Banafit rigura 1 Tha marginal banafit and marginal coat: of raducing bycatch and tha optimum laval of bycatch. rigura 2 Tha marginal banafit, marginal coat of raducing bycatch with coat affactiva mathoda (MCI), marginal coat of raducing bycatch without coat affactiva mathoda (KC2), and tha optimum lavala of bycatch with and without cost affactiva mathoda of raducing bycatch. Marginal Cost Marginal Banafit Figura 3 Tha marginal banafit to tha fisharman (MBF) , marginal banafit to aociaty Including tha flaharaan (Mas) . aarginal coat (MC) of raducing bycatch, and tha o p t i m u m laval* of bycatch. rajpactlvaiy. for tha fiaharman and f a r s a c i ? t v -14 BYCATCH MORTALITY IMPACTS AND CONTROL FOR PACIFIC HALIBUT Bruce M. Lea man, Department of Fisheries and Oceans, Pacific Biological Station, 3190 Hammond Bay Road, Nanaimo BC V9R 5K6, Canada. ABSTRACT The groundfish trawl fishery off British Colum-bia is characterized by multispecies landings which arise through both biological associations and the fishery management regime. Catches of many species may be discarded at sea due to lack of markets, size constraints of existing markets, catch prohibition, or quota/trip limit restrictions. Mortality of the discarded species varies with the fishing method and the biology of the species. The fishing gear characteristics, as well as the exploitation histories and underlying productivities of the target species which are caught together limit the opportunities for joint yield optimization of these target species. In addition, incidental mortality on species which are not targets for the trawl fishery decreases yield in fisheries for which these species are the targets. This paper examines some of the econ-omic impacts of bycatch in British Columbia trawl fisheries from the perspectives of lost yield, management costs, and the impact on knowledge of the population dynamics of non-target species arising from bycatch mortality. The primary focus of this paper is on the impacts of bycatch mortality of Pacific halibut arising from capture in trawl fisheries. The management program for Pacific halibut is one of the few management regimes in the world that incorporates explicit recognition and accounting for bycatch mortality. The Interna-tional Pacific Halibut Commission reduces the catch quota for the directed halibut fishery to account for bycatch mortality occurring in trawl fisheries from Alaska to B.C. For 1994, this reduction totalled over 1100 t and resulted in a catch quota of approximately 4500 t for B.C. waters. Coastwide, the reduction for bycatch was approximately 27% of the final halibut quotas for Canada and the United States. In 1991, Canada and the United States began a cooper-ative program of bycatch monitoring and control to reduce the impact of bycatch on the Pacific halibut resource. Control of bycatch has been difficult and has not been achieved without significant costs in other fisheries. The paper reviews some of the lessons that have emerged from this process. Coastwide bycatch mortality has been reduced from approximately 7900 t in 1990 to approxi-mately 6900 t in 1993. Canada will be imple-menting direct bycatch control measures in 1995 and has established a target mortality of approxi-mately 490 t in 1997, a reduction of 50% from 1991 levels. Data collected from observer pro-grams and directed research studies are produc-ing the information necessary to design and monitor programs to achieve this result. The paper examines some of the economic trade-offs which must be considered in the design of bycatch control measures. Finally, the paper explores the impacts of discard mortality on our understanding of the population dynamics of non-target species. ? ? ? INTRODUCTION The British Columbia groundfish trawl fishery shares features with most trawl fisheries in the world. It is prosecuted with fishing gears that have limited selectivity and yields multispecies catches with relatively high proportions of discards at sea. In addition to the voluntary discard of fish arising through market forces, discarding can also be mandated by management prohibition, or arise through the interaction between biological associations and the manage-ment framework used to enforce quotas for species or species groups. While the quantity of fish discarded can often be 50% of higher of that actually landed, few species management pro-grams in the world provide adequate recognition and accommodation for this mortality. In this paper, I examine the magnitude of the discard problem in the British Columbia trawl fishery, as determined through by on-board observations in one the major fishing areas, the myriad causes for discarding, and the impacts of discarding Pacific halibut (Hippoglossns stenolepis) in a non-target fishery on the yield available to a target fishery for this species. I also present the measures that have been taken on an interna-tional level to control and reduce bycatch mortal-ity of Pacific halibut and illustrate the tradeoffs associated with some of these control measures. 15 Causes of Bycatch and Bycatch Mortality The operational definition of bycatch used in this paper is that portion of the catch by a given gear that is, for any reason, unwanted by the har-vester. Bycatch mortality is the mortality gener-ated through this catching process and the subse-quent treatment of the catch. Bycatch is then fundamentally an issue of the selective properties of the fishing gear. If the fishing gear were perfectly selective for the species and sizes desired in the market, there would be no bycatch. Such selectivity is exceedingly uncom-mon and is usually restricted to harvesting methods involving visual identification of targets prior to harvest. More commonly, fishing gear shows imperfect selectivity, ranging from highly selective for species or sizes to non-selective. The selectivity may be entirely a function of the gear itself, e.g. mesh or hook sizes, or may be related to associations of species in the habitat in which the gear is deployed. Bycatch itself is therefore largely a passive function of fishing gear and deployment in conjunction with the distribution and biology of the species involved in fishing. Conversely, bycatch mortality is a much more complex and active process. The major contributors to bycatch mortality can be segregated into direct and indirect factors. A listing of the major factors under these categories (Table 1) finds both those which are under the control of the individual harvester and those driven by econ-omic forces quite removed from actions aboard an individual vessel. Table Factors affecting bycatch mortality in fisheries. DIRECT FACTORS Depth of capture Duration of fishing Species mixture and quantity in catch (e.g., smooth-bodied vs. spiny) Anatomy and Physiology of the species concerned Size and age of the individual Temperature and exposure to desiccation Handling practice and time prior to discarding INDIRECT FACTORS Market acceptability limits on species and sizes of fish Vessels' capability to process catches to meet market specifi-cations (e.g., freezing) Management prohibition on retention by specific gears Management measures which are do not account for the multispecies nature of catches within fisheries (e.g., indi-vidual species trip limits in multispecies fisheries) Impacts of Bycatch Mortality Assessing the impacts of bycatch mortality requires attention to both obvious and obscure processes (Table 2). The most direct impact that fishery biologists should consider regularly is the impact on population dynamics and yield of target species for which there is bycatch mortal-ity of juveniles. However, this mortality compo-nent is seldom considered, even though it is arguably the most obvious impact of bycatch. Stock assessment biologists seldom have infor-mation on the levels of discards for target spe-cies in even the most well documented fisheries. For example, the British Columbia groundfish trawl fishery is subject to compulsory logbook reporting of catch and effort, on a tow-by-tow basis. Although the logbooks contain provision for discard reporting, harvesters seldom provide such data. Assessment biologists therefore know little about the quantities and species composition of the discarded catch. Research survey data are sometimes used to estimate the probability of discarding for given size or age groups but this information is generally insufficient for estima-tion of specific time and area impacts. Table 2. Impacts of bycatch mortality and bycatch control measures DIRECT IMPACTS Loss of recruits to fished population through juvenile discards Ecological impacts related to predator-prey and competitive interactions Economic impacts through lost or enhanced yields of target species Costs of enforcement for bycatch control Costs of monitoring and management INDIRECT IMPACTS Loss of future yields for species targeted by other fisheries (e.g. halibut, crab) Extended economic costs concerning undeveloped processing and marketing potential Ecological effects through long-term dynamics of communities Effects on dynamics of individual species subject to bycatch mortality Effects on the information basis for stock assessment of both tar-get and non-target species The magnitude of the bycatch problem in the B.C. trawl fishery is beginning to be docu-mented through observer placement aboard fishing vessels. Observer data gathered in the shallow water fisheries of Hecate Strait during 1991-1992 illustrates the general nature of discarding (Table 3). Discards in this fishery during the period averaged 56% of the landed 16 TaMa 3. Summary of obaarvad catcit and SUMMER SPECIES docarda for tha fiahary in Hacata Strart. 1991-1992. iCATCH OtSCARO PROP. WINTER CATCH DISCARD PROP. COMBINED COMBINED CATCH DISCARD PROP. Arrowtooth floundar Big skats Black rockfish Bkjarockfish Boca< 1' Buttarada C-Oaota Canary rockfiah China rockfiah Coppar rockfiah Curtfin ao4a Darkfekftchad rockfiah Dover sol* Engfiah aota Flathead aoie Greenings Greenatriped rockfish Kelp flraaninfl Ungood Longraaa skate Pacific cod Pacific haka Pacific hafetxjt Pacific herring Pacific ocaan parch Pacific aanddab Pacific tomcod Petrale sole Poachers P rw f i sh Ou?b?ck rockfish Redbanded rockfiah Redstripe rockfish Rax to la Rock tola Rosethcm rockfiah Rougheye rockfiah Sablefish Salmon Sand aola Sandpaper akata Scu lpra Shad Shirar parch Shortspine thcmyhead Sitvergray rockfiah Skates Slender sola Speckled sanddab Spiny dogfish Spotted ratfish Starry floundar Starry skate Sturgeon poachar Tiger rockfiah VemraSon rockfiah Walleye poloek Widow rockfish Wolf eel Yellowaya rockfish Yalkw?mouth rockfish Yertowtaj rockfish (kg) (kg) (kg) (kQ) (kg) <*fl) 76695 7G695 1.00 32306 32011 0 99 109000 108706 1.00 16130 14020 0.87 4395 4395 1.00 20525 18415 0.90 18 O 0.00 227 0 0.00 245 0 0.00 0 0 (LOO 40 0 0.00 40 0 0 0 0 191 65 0.34 2134 0 0.00 2325 65 0.03 14461 7310 0.51 209 209 1.00 14670 7519 0.51 124 124 1.00 96 96 1.00 220 220 1.00 1838 47 0.03 417 145 0-35 20S5 192 0.09 fraca taoa 0.00 0 0 0.00 0 0 0.00 110 0 0.00 90 0 0.00 200 0 0 0 0 20 20 1.00 59 59 1.00 79 79 1.00 363 208 0.56 406 0 0.00 771 209 0.27 0 O 0.00 131 131 1.00 131 131 1.00 36311 9672 0.27 13237 4650 0.35 49548 14322 0.29 87196 56701 0.65 121945 64805 0.53 209143 121506 0.58 1835 fraca 1036 0.63 1654 1854 1.00 3289 2690 0.82 traca 0.00 55 55 1.00 55 55 1.00 0 0 0.00 traca t r c a 0.00 0 0 0.00 traca traca 0.00 fraoa trace 0.00 0 0 0.00 9623 145 0.02 21872 115 0.01 31495 260 0.01 1190 1140 0.96 16819 16819 1.00 18009 17959 1.00 135268 10577 0.06 185022 4850 0.03 320288 15427 0.05 0 0 0.00 15 15 1.00 15 15 1.00 36995 1.00 10710 10710 1.00 47705 47705 1.00 77 77 1.00 545 545 1.00 622 622 1.00 496 310 0.62 1402 0 0.00 1900 310 0.16 1122 1122 1.00 148 148 1.00 1270 1270 1.00 0 0 (LOO 78 78 1.00 78 78 1.00 1477 695 0.47 7903 1703 0.22 9380 2398 0.26 0 0 0.00 236 236 1.00 236 236 1.00 0 0 0.00 3 3 1.00 3 3 1.00 439 0 0.00 508 55 0.11 947 55 0.06 417 0 0.00 491 0 0.00 908 0 0.00 151 109 0 72 3695 543 0.15 3846 652 0.17 12556 11196 0.89 19722 15535 0.79 32278 26731 0.83 193057 92920 0.48 57194 21428 0.37 250251 114348 a 46 97 0 0.00 0 0 0.00 97 0 0.00 64 0 0.00 0 0 0.00 64 0 0.00 9661 9163 0.95 9681 9681 1.00 19342 18844 0.97 traca toaca 0.00 64 62 0.97 64 62 0.97 12022 5821 0.49 15812 14189 0.90 27834 20110 0.72 10 10 1.00 237 237 1.00 247 247 1.00 0 0 0.00 111 111 1.00 111 111 1.00 traca traca 0.00 91 91 1 0 0 91 91 1.00 0 0 0.00 153 153 1 0 0 153 153 1.00 1242 302 0.24 136 136 1 0 0 1378 438 0.32 373 0 0 0 0 9124 388 0.04 9497 388 0.04 31133 31133 1.00 41257 40966 0.99 72350 72119 1.00 0 0 0.00 7 7 1.00 7 7 1.00 0 0 0 00 277 227 0.82 277 227 0.82 87734 87734 1.00 43672 43672 1.00 131*06 131406 1.00 19620 19620 1.00 24910 24910 1.00 44730 44730 1.00 8618 8558 0 99 3967 3987 1.00 12605 12545 1.00 0 0 0.00 30 X 1.00 30 30 1.00 0 0 0.00 29 29 1.00 29 29 i .oo 0 0 0.00 traca traca 0.00 0 0 0 0 0 0 0 0 0 0 5 0 0.00 5 0 0.00 7639 4256 0 5 6 2*269 17612 0.73 31908 21868 0 6 9 traca traca 0 0 0 215 10 0.05 215 10 0 05 70 70 1.00 35 35 1.00 105 105 1.00 50 0 0.00 279 0 0.00 329 0 0.00 0 0 0.00 150 0 0.00 ISO 0 o.oo 1253 967 0 7 7 598 50 0 0 8 1851 1017 0 55 807548 489119 0.37 678894 337595.88 0 5 8 1486442 826715 0 56 TOTAL I AVERAGE i7 catch, i.e., for every 1000 t of fish landed, over 500 t was discarded. The proportion discarded is higher during summer months, when averaged across all species, although the proportion of the total catch discarded during the winter months was higher. Of the species with significant discard ratios (Fig. 1), only Pacific halibut must be discarded by regulation. All other discards result primarily from a lack of markets for the sizes or species obtained. In several instances (e.g. some flatfish spp.) discards could be reduced through gear modifications, such as larger mesh sizes. Hecate Strait Trawl Fishery Observed Vessels 1991-1992 POTMHH SMfQTI|f M M ) Smny kuW I ? -b LorgneM skaH mm ! ? CATCH ? DISCARD | ? g n a w > S m a o M 5L o wauycpoaock S . ft?M* ' SeomarMMi Oomtm* SkMu P K k M t t f = = -Afmrtootfi Bowjv Spnyfegfaft Engun Ma P K O C M 0 lOOCGO 200000 30CC00 Catch/Discard (kg) Figure 1. Catches and discards of groundfish species observed on Canadian trawlers operating in Hecate Strait during 1991-1992. Perhaps the most insidious effect of bycatch mortality for target species is generated through discarding and misreporting of target species to accommodate or circumvent management measures for individual species, in mixed-species fisheries. For example, there are approximately 24 stocks of nine species of rockfishes (genus Sebastes) assessed in British Columbia. These stock units, which have considerably different exploitation histories and current productivity levels, are presently compressed into three coastwide aggregates for management. This compression is a direct consequence of industry practices of misreporting and discarding of species to overcome constraints imposed through a previous management regime, which attempted to manage these stocks individually. The aggre-gation of individual stock yields into coastwide aggregates has led to significant imbalances in removals relative to available yield for some of these stock units (Leaman 1990). The costs of this approach to the long-term yield from these stock units is not yet fully understood but may be substantial. A further cost of aggregation is a comprehensive dockside monitoring program for all landings from the fishery. This program imposes a shared cost on both industry and government of approximately $700,000/y, solely to provide accurate landing statistics for this management program. The level of discarding at sea to used to circumvent annual quotas and individual trip limits on these aggregates remains unknown. The discussion of bycatch mortality impacts on non-target species seldom passes beyond the speculative, due to the paucity of information on either the quantities of discards or the parent stock from which they were derived. Unless these non-target species are themselves the objects of directed fisheries, insufficient knowl-edge exists to estimate the degree of fishing mortality imposed through bycatch. A notable exception is the Pacific halibut (Hippoglossns stenolepis), which will be treated in the second portion of this paper. Where bycatch reduction and control programs are in place, two major impacts of such pro-grams dominate consideration: the cost of moni-toring, managing, and enforcing them; and, the economic losses associated with either adherence to restrictions in target fisheries, or continued bycatch mortality on non-target species when restrictions are not adhered to. TTiese aspects will also be discussed with respect to the interac-tions of groundfish trawl fisheries and the directed setline fishery for Pacific halibut. Finally, an impact of bycatch mortality that is less visible but of significant consequence is the impact on our knowledge base for stock assess-ment. The most benign form of this impact occurs where there is chronic but stable discard-ing of either target or non-target species. Here, the additional fishing mortality from discarding will be transparent to most stock assessments and be generally subsumed within the estimated natural mortality rate. More destructive to assessment data sets are instances where bycatch is highly variable within years or in response to incremental management measures. For example, under previous management regimes 18 for the B.C. trawl fishery the early subscription of trip limits for some species would often result in higher reported landings of species with normally low levels of incidental occurrence. This scenario suggests high levels of discarding for species with fully-subscribed quotas, in order to accrue sufficient landings of these alternative species. The alternative of misreported landings of these alternative species to avoid prosecution for illegal landings of the primary species creates equally problematic data. Unreported discards of minor species also has the impact of removing any opportunity to observe unfished stock char-acteristics. Productivity of such resources will generally tend to be overestimated if observed characteristics are mistakenly assumed to repre-sent the unexploited condition. PACIFIC HALIBUT BYCATCH Historical Perspective The Pacific halibut is the object of a major directed fishery off the west coast of North America, extending from the Bering Sea to Oregon. This lucrative fishery yielded over 59 Mlb in 1994, worth over $200M (U.S.) to har-vesters (IPHC 1994). Pacific halibut have a complex reproductive biology involving spawn-ing migration of adults and consequent counter-migration of juveniles. Although smaller amounts of spawning occur throughout the coast, the majority of halibut spawners migrate toward the central Gulf of Alaska (Fig. 2, Areas 3A/B) in the winter months. Eggs and larvae drift with prevailing westerly currents to the western Gulf and eastern Bering Sea. Juveniles begin migrat-ing back in an easterly and southerly direction beginning at about age 2 y and are intercepted by target fisheries for other species between ages 2-7 y. The primary fisheries of interception are trawl (both groundfish and shrimp) and hook and line fisheries in the Bering Sea (Area 4), Gulf of Alaska (Areas 2C-3A), trawl fisheries off British Columbia (Area 2B), and trawl fisheries off Washington and Oregon (Area 2A). Historically, bycatch mortality of Pacific halibut occurred primarily in fisheries conducted by foreign distant-water trawlers operating in Alaskan waters. Bycatch mortality rose to over 20 Mlb in the mid-1960s but was reduced to approximately 7 Mlb following the promulgation of extended fisheries jurisdiction by North American states in 1977 (Fig. 3). Coastwide Figure 2. Regulatory areas of the International Pacific Halibut Commission for the west coast of North America. bycatch increased after 1985 as the U.S. "Americanized" the fisheries of the Bering Sea and Gulf of Alaska. U.S. factory trawlers fishing for pollock, flatfish and Pacific cod were the source of most of this increase. Estimated bycatch mortality in Area 2B (B.C.) during the same period was relatively stable (Fig. 3), and was generally below 2 M!b. The bycatch of halibut in B.C. is highest in Hecate Strait, followed by Vancouver Is. and Queen Charlotte Sound, with fisheries for shallow water soles and Pacific cod accounting for the majority of bycatch mortality. Halibut Bycatch Mortality Total Stock Art* 2B Figure 3. Bycatch mortality of Pacific halibut for British Columbia waters (Area 2B) and the entire west coast of North America, 1962-1993. 19 Bycatch is a joint function of fishing effort, the abundance of the target species, and the abun-dance of the non-target or bycaught species. The influence of halibut juvenile abundance on bycatch can be inferred from data relating abun-dance of juvenile halibut in the Bering Sea, estimated through systematic research trawl surveys, to bycatch of halibut in groundfish fisheries (Fig. 4). The declining bycatch of halibut following extended jurisdiction, although clearly related to a number of area closures and bycatch restrictions imposed on foreign vessels, also occurred during a period of declining abun-dance of juvenile halibut. Conversely, the increasing bycatch after the Americanization of the Alaskan fisheries was coincident with increasing abundance of halibut juveniles in the Bering Sea. Juvenile Abundance (Year t-1) vs. Bycatch (Year t) Bycatch (000 t) Juveniles (million} Figure 4. Relationship of the bycatch of halibut juveniles in the Bering Sea and the abundance of halibut juveniles estimated by trawl surveys in the previous year, 1975-1991. Compensation Measures The Pacific halibut resource is managed jointly by the U.S. and Canada through the International Pacific Halibut Commission (IPHC). The IPHC is one of the few management agencies in the world that attempts to deal explicitly with the effects of bycatch mortality on the exploitable stock. The IPHC has developed estimates of losses to the halibut stock due to lost recruit-ment, lost reproductive potential, and total lost yield (Table 4). At present, the Commission attempts to compensate the stock for bycatch mortality through reductions in directed fishery quotas to replace the potential egg production lost through bycatch. Compensation is calcu-lated on a coastwide pool basis because of the observed spawning behaviour but assigned to each management area in proportion to the distribution of adult biomass. Compensation thus accounts for the movement of juveniles out of the areas of bycatch occurrence. However, this has the novel effect of dissociating some of the areas where bycatch originates (primarily the Bering Sea) from the penalties in lost yield that are paid (Gulf of Alaska and further south). Table 5 shows the relation of bycatch source and these yield reduction penalties among manage-ment areas. Table 4. Losses due to bycatch mortality of Pacific halibuL RECRUITMENT LOSS No adjustment to compensate for Average loss in adult equivalent weight is 1.2 times weight of bycatch LOST REPRODUCTIVE POTENTIAL IPHC adjusts setline yield to attempt to compensate the stock Lost recruitment (1.2) times the ratio of adult equivalent biomass to recruitment biomass (0.83) is used to replace egg production lost through bycatch The resulting 1.0 is the adult equivalent biomass subtracted from the setline quota for each lb of bycatch (adult reproductive compensation) TOTAL LOST YIELD Adult reproductive compensation (1.0), of which 0.6 will eventually be caught in subsequent years in the fishery - > 0.4 + Lost recruitment biomass = 1.2 times bycatch Results in a total yield loss of 1.6 lb/ lb of bycatch The measures adopted by the IPHC for bycatch compensation result in substantial penalties paid by B.C. halibut fishers for bycatch mortality occurring in Alaska. For example, in 1995 the total quota reduction of halibut extracted to compensate the stock for bycatch mortality will be approximately 16.0 Mlb, to which bycatch mortality in B.C. contributed 1.3 Mlb. How-ever, B.C. fishers will pay a total of 3.05 Mlb in quota reduction penalties, of which 2.8 Mlb accrues to B.C. solely due to bycatch in U.S. waters. While the system used by the IPHC also results in direct penalties to U.S. halibut fishers for Canadian bycatch, the balance is strongly against Canada. This imbalance, coupled with the increasing trend in U.S. bycatch in the late 20 1980s, triggered a landmark agreement to con-trol and reduce bycatch mortality between the two countries in 1991. The 1991 IPHC Bycatch Reduction Agreement Canada and the United States, through the IPHC, agreed in 1991 to embark on a process of halibut bycatch mortality control and reduction. A Halibut Bycatch Work Group (HBWG) was created by resolution of the Commission and produced a series of recommendations, that were adopted by the Commission in July 1991 (Salveson et al. 1992). The HBWG conducted an extensive investigation of the bycatch issue, reviewed existing measures for bycatch control, and detailed a number of mechanisms that could be implemented to reduce bycatch mortality. The group identified the low levels of bycatch mortality achieved in the mid-1980s as a desir-able goal for reduction. Notably, the group also identified that increasing the survival of those fish which were caught and discarded would likely be as. or more, effective than decreasing the number of fish actually caught in non-target fisheries. This recognition provided support for alternative measures of bycatch mortality reduc-tion to traditional measures involving only time and area prohibitions. . The 1991 agreement identified a process, a timetable and a target. In particular, the United States agreed to bring all fisheries under bycatch limits for 1992 and to implement a program to reduce bycatch limits by a minimum of 10%/y beginning in 1993. Canada has subsequently committed to bring its bycatch mortality down to 1.0 Mlb by 1997. Measures Used to Monitor and Control Halibut Bycatch The most significant feature of bycatch reduction programs is the development of a process to estimate bycatch and monitor changes resulting from various reduction measures implemented. The U.S. began a comprehensive program of monitoring in the early 1990s which is now funded directly by harvesters. This program involves 100% observer coverage for vessels >125" in length and graduated observer cover-age for smaller vessels. The program cost is variable but is generally in the $15-20 M range. This program is designed to estimate bycatch through direct observation. Canada has also implemented an observer program, although it is not user-funded. It is designed to estimate accurately the ratios of halibut bycatch to target species catches for the purpose of extrapolation to total bycatch. A variety of measures to control and reduce bycatch mortality in the two countries have been implemented since the 1991 agreement. These include: bycatch caps or limits for areas and fisheries; time/area closures; bycatch perform-ance standards for specific fishing gears; sea-sonal apportionment programs for bycatch caps to prolong fishing seasons; fishing gear modifi-cations to reduce encounters of halibut; careful release programs involving grid sorting and manipulation of fish on hook gear; and, vessel incentive programs designed to reward fishing to lower bycatch levels, through access to addi-tional target species' quotas. The implementation of these measures has not been without controversy. They involve direct control of valuable groundfish fisheries and. particularly during the initial years of implemen-tation, direct penalties in terms of forgone groundfish yield due to fishery closures as bycatch caps were reached. For example, in 1992 fishery closures associated with bycatch control resulted in forgone groundfish harvests of over 174,0001 in Alaskan waters. This econ-omic cost to the groundfish industry represents a substantial proportion of the total worth of the halibut fishery. This comparison has fuelled intense debate on the merits of protecting a halibut fishery within the U.S. management Table S. Example of apportionment of catch limit reduction! by tbe IPHC (reproductive compeesatioc) by regulatory area for effcco of bycatch mortality in 1992. Area Exploit. Biomas Bycatch Mortal. 2A 2B 2C 3A 3B 4 Too l 2A 2.59 05 0.00 008 aio 023 004 oos 050 2B 49J0 U 001 026 033 073 O i l 015 L60 2C 61 J * 07 001 a n O H 032 005 007 073 3A 136.64 5 J 005 017 1.09 2.41 037 051 5J5 3B 21.12 4 2&A3 6J 006 L I2 1.40 3-09 04S 065 <J3 Total 300J6 14.9 113 2.45 3.07 6.78 LOS 1.43 14.9) 21 system. It is some tribute to the resolve of both countries that adherence to the principles of the 1991 agreement has been maintained. The recognition that groundfish catches similar to those at present were harvest by foreign fleets in the mid-1980s with much lower halibut bycatch, has helped to support this resolve. Canada has. explored similar approaches to fishery closures and the flavour of the economic tradeoffs involved can be seen in Table 6. Table 6. Economic tradeoffs associated with potential closures of nawi fisheries oft the west coast of Vancouver Island. VANCOUVER ISLAND TRAWL FISHERY (Based on 1976-1990 monthly averages) Wj, June M ? A n t i i r v - l Cuail annul GreuwJlWi card (il i m o IDffTi ttli U M J MOWJ Kalsbui onrtalirp (opo Th h l t i i C I [SOS.J ?.. a< XREA ( r a u d f l i k m m tl lrMi 14.7 ? J t U n o * Ot AJtTJ. famlibol ? n-i.i ? 1 tOUJ ISA M J 21.4 T7.I at CT3AVT fiiHindnm inaui j totjJ 4,1 J J * COAST kiUbw V "r I totij ?J ?.? 6 5 Vikie ot [roiudfiih (1034/Tb) IO.S96M W.lfflCM W449M Value of hxl2>ui (USD/lb) I&2IDM WJ5JM IOBUM There have also been significant costs to the implementation of bycatch reduction that were not recognized explicitly at the beginning of the program. Aside from observer programs costing millions of dollars, catch monitoring programs, enforcement and prosecution, and the research required to evaluate reduction measures (e.g. physiology research and tagging programs to estimate viability of discarded fish) have resulted in substantial costs in the program of bycatch reduction. Progress on Bycatch Reduction Coastwide halibut bycatch mortality declined from a high of 18.101 Mlb in 1990 to 15.189 Mlb in 1993. Some of this decline resulted from changes to our estimates of discard mortality rates for bycaught fish, and the remainder from lower actual catches of halibut. Discard mortal-ity was reduced through modified fishing prac-tices and improved estimation of halibut condi-tion resulting from observer data. However, in 1994 coastwide bycatch mortality again rose, to 15.996 Mlb, in spite of a reduction in Canadian bycatch mortality from 1.661 to 1.305 Mlb over the same period. The lack of adherence to U.S. mortality caps resulted largely from difficulties in projecting closure dates for trawl fisheries due to large variability in fleet composition, and higher than estimated incidence rates in rock sole and turbot fisheries. Future progress on bycatch reduction is some-what uncertain, although both countries have re-affirmed their commitment to the 1991 agree-ment. There are presently no measures to reduce bycatch mortality caps in Alaskan waters before U.S. management agencies. Canada remains committed to achieving a 1.0 Mlb bycatch mortality limit by 1997 and has imple-mented a mortality cap in Hecate Strait for 1995. This will be followed by additional caps for the west coast of Vancouver Island and Queen Charlotte Sound as required in 1996 and 1997. Lessons from the Halibut Bycatch Reduction Program A number of important lessons have emerged from the joint efforts of the United States and Canada to reduce halibut bycatch mortality. Perhaps the single most important lesson is that a recognition of the need for change must be established in the minds of regulators. If man-agement agencies do not share user groups' perceptions of the need to reduce bycatch, implementation of programs will be delayed or frustrated at every potential occasion. Another important lesson is that we cannot have everything. That is, achievement of the goal of bycatch reduction requires recognition that bycatch mortality cannot be reduced to zero without elimination of some other fisheries. It will clearly be unacceptable to eliminate groundfish fisheries solely to eliminate bycatch mortality for halibut. Participants in all fisheries must be willing to accommodate the needs of other sectors if progress is to be made. How-ever, participants must also acknowledge that halibut bycatch is presently higher than it needs to be in order to harvest the full groundfish quotas. Decisions on bycatch control measures involve millions of dollars worth of halibut and groundfish harvests, and proponents of particular measures can be expected to be well-funded and persistent in supporting measures they favour. 22 This persistence will translate into prolonged lobbying of management agencies for desired results. Efforts to effect change will therefore be most effective if they are pursued within a joint optimization framework for target and non-target species. The information that is necessary to evaluate alternative measures is highly detailed and analyses may be complex. Collection and analy-ses of these data will be correspondingly expens-ive and user groups can expect to bear some or all of the costs for these programs. These "hidden" costs to implementation of bycatch control, and the need to generate the regulator]' authority to recover these costs, have been a significant component of the difficulty in reduc-ing bycatch mortality. Finally, the efforts to reduce bycatch mortality have been extremely slow in large measure because it has been difficult to implement reduc-tion measures that incorporate individual respon-sibility for bycatches. Most of the measures that have been implemented have been applied at the level of entire fleets or gear sectors. Many of these measures have foundered on the reality that fleets do not act in the best interests of individ-uals. The absence of mechanisms to effect control and reduction measures, and more importantly to provide incentives, at the individ-ual vessel level was an important element in the slow progress achieved in the initial stages of the halibut bycatch control program. Regulators have now recognized that embedding individual responsibility in such programs is often the most important prerequisite to success. ACKNOWLEDGEMENTS I am grateful to Jeff Fargo for provision of information from observer trips on British Col-umbia trawlers and for comments on the presen-tation. I also thank staff of the International Pacific Halibut Commission for assistance in the preparation of some estimates of reproductive compensation measures used by the Commission. LITERATURE CITED International Pacific Halibut Commission. 1995. Report of assessment and research activities, 1994. Int. Pac. Hal. Comm. Seattle, WA. 274p. Leaman, B. M. 1990. Slope rockfish. pp. 195-258 In Tyler, A. V. and J. Fargo (eds.) Groundfish stock assessments for the west coast of Canada in 1989 and recommended yield options for 1990. Can. Tech. Rep. Fish. Aquat. Sci. 1732:343p. Salveson, S., B. M. Leaman, L-L. Low, and J. C. Rice. 1992. Report of the halibut bycatch working group. Int. Pac. Halibut Comm. Tech. Rpt. 25:29p. 23 THE IMPLICATIONS OF VOLUNTARY AND REGULATORY SOLUTIONS TO BYCATCH AND DISCARD IN THE ROCK SOLE FISHERY John R. Gauvin & Joseph R. Blum, American Factory Trawler Association, 4039 -21st Avenue West, Suite 400, Seattle, Washington 98199, USA ABSTRACT Approximately 65% of the catch by weight in the Bering Sea and Aleutian Islands (BSAI) rocksole fishery was discarded last year. Rocksole is targeted for its roe although the flesh of large rocksole is utilized. Discard is motivated by the fact that small rocksole lack roe and command very low prices. Production costs for small rocksole would exceed revenues even for the most efficient trawlers. The rocksole stock and stocks of bycatch species are all believed to be healthy according to stock assessments. The allowable biological catch (ABC) for rocksole was 313,000 mt in 1993, but the total allowable catch (TAC) was set at 75,000 because of a two million mt ecosystem removal cap. Only 60% of the rocksole TAC was taken in 1993 because the bycatch allowance for Pacific halibut was taken before the TAC was met. Thus the bycatch/discard problem in this fishery is not overfishing of rocksole or bycatch species, but a perceived resource waste issue. This presentation will discuss resource waste and mandated full utilization which would reduce efficiency and bring about economic losses. Three proposed bycatch/discard solutions will be outlined as they relate to the rocksole fishery. The first is an industry proposal to increase mesh size. The second proposal, called "Harvest Priority", is billed as a reward program. It would take away fishing time from vessels whose bycatch rates exceed an industry-proposed standard by gear and area. Fishing would still be conducted in a common property race for fish. The final proposed solution is an individual transferable quota system (ITQ) with tradable rights to bycatch species. The bycatch/discard reduction mechanism of the ITQ is expected to result from elimination of the common property race and the potential for rights to flow to har-vesters who fish with the lowest bycatch. In addition, the ITQ proposes gradual reductions in ITQs for bycatch species when ITQ shares are transferred. ? ? ? Bycatch and discard will likely be the primary focus for fisheries management for the remainder of this decade. Of great concern, from the perspective of the fishing industry, is that the issue of bycatch and discard is being oversim-plified and the facts are being misrepresented in a wholesale manner. For one, due to erroneous statements and the lack of a thorough and unbiased treatment of the issue, bycatch and discard are generally construed to be related to or associated with overfishing. As a conse-quence, for the average person who follows environmental concerns, a thematic link exists between bycatch, discard, and overfishing. There are, however, significant departures from this convenient rule of thumb of "they're wiping it out and they're wasting it all" that certain environmental groups contend. One very large departure to this rule of thumb is in the largest fisheries in the United States, the fisheries of the North Pacific: the Gulf of Alaska and the Eastern Bering Sea. Biological assess-ments of the fishery resources in the North Pacific confirm that overfishing is not occurring for most species. Yet in Bering Sea and Gulf of Alaska fisheries, bycatch and discard in terms of tonnage are relatively high, by virtue of the magnitude of the fisheries in the region. To complicate matters, data from an independent fishery observer program in the North Pacific show that bycatch rates per ton produced are generally low compared to other United States fisheries or fisheries around the world (NRC, 1994). This serves to muddy what some envi-ronmentalists want the public to believe. In fact, the more the public learns about the fisheries of the North Pacific, the more complicated the issues and tradeoffs are likely become. Why focus on the Rock Sole Fishery? As attention has been focussed on what advocacy groups are calling "waste" in the North Pacific, the fishery for rock sole (Pleuronectes 24 bilineatus) in the Bering Sea/Aleutian Islands (BS/AI) has received a great deal of scrutiny. One reason is that in 1993, approximately 65% of the groundfish brought on board in the fishery was discarded. This is the highest discard rate for a trawl fishery in the North Pacific. In fact, it is four times higher than the average discard rate for trawl fisheries in the Bering Sea in 1993 (Pacific Associates, 1994). This paper focuses on rock sole because it is a North Pacific fishery where bycatch is large in absolute terms as well as in terms of a rate per ton. The rock sole fishery is exceptional for the North Pacific because, in some ways, it does fit the mold of what environmentalists contend is occurring in the North Pacific. On the other hand, the link between overfishing and bycatch espoused by the environmental group does not fit the rock sole fishery and really fits none of the North Pacific fisheries at all. Through this discussion of the rock sole fishery, it is hoped that the reader's appreciation for the complexity of the bycatch/discard issue, its causes, and the tradeoffs involved with potential "solutions" will be enriched. The Rock Sole Fishery Although rock sole is a relatively insignificant fishery in the BS/AI management area in terms of tonnage, comprising only 5% of the overall BS/AI trawl catch in 1993, the 65% discard rate in the fishery does bring the fishery to the forefront in terms of potential regulatory fixes to the bycatch/discard issue. In contrast, the midwater pollock (Theragra chalgogramma) trawl fishery in the Eastern Bering Sea accounted for 1.3 million metric tons in 1993 (67% of overall BS/AI landings), and only 49,000 metric tons of this have been discarded (a discard rate of four percent). The rock sole fishery produced approximately 22,400 metric tons of retained landings of rock sole in 1993, worth approximately $34 million dollars at the first wholesale level. Roe rock sole was the principle component of revenue from the fishery. Roe rock sole are typically frozen whole or headed and eviscerated with the roe left in the body cavity. Roe is removed from fish when secondary processing occurs. Most roe rock sole is exported to Japan. The flesh of the rock sole is consumed separately after the roe is removed. Approximately 25 vessels targeted roe rock sole in 1994. All of these vessels were trawl catcher/processors and most of these boats were at-sea processors that head, eviscerate, and freeze product on board. Vessel lengths typical-ly range from 140 to 250 feet, which is con-siderably smaller than catcher/processors with more sophisticated processing capability. To understand the fishery, it must first be recog-nized that rock sole are targeted principally during a four to six week period from January 20 to the beginning of March. During that time, the fishery is an Olympic style fishery wherein fishermen compete for rock sole before the prohibited species bycatch caps (PSCs) for halibut or red king crab are exhausted or the prime roe period is over, the former being more likely to occur before the latter. The total allowable catch limit for rock sole does not drive the race for fish in the fishery because prohibited species caps and other management regulations generally mean that the rock sole fishery is closed long before the total allowable catch limit is met. Female rock sole with the highest recovery rate of roe receive the highest prices and females without roe and male rock sole command rela-tively low prices. Even during the peak of the roe rock sole period, catches include rock sole without roe, Pacific cod, pollock, and flatfish other than rock sole (flathead sole, rex sole, yellowfin sole, Alaska plaice etc.). In addition, considerable quantities of other species that are generally considered to have no or very low commercial value such as skates, rays, demersal sharks, and arrowtooth flounder are taken. With the race for rock sole before the king crab or halibut prohibited species catch limits are met, fishermen generally process only the highest-valued species which can mean only roe rock sole or roe rock sole and Pacific cod and some large flatfish other than rock sole. Although distasteful to some, this is economical-ly rational behavior because to fill freezer space with species other than roe rock sole could mean that the vessel would have to offload processed product earlier and might not be able 25 to return to the fishing grounds before the season was over. Even if freezer space were not criti-cal in terms of having to offload and thus forfeit-ing a second roe rock sole trip, retaining these other species would result in lost fishing time during the window of time when the fishery is open and rock sole roe recovery and quality is high. Another mitigating factor in the decision to retain or discard Pacific cod and other round fish species with commercial value is that round fish are frequently in less-than-optimal condition when captured in conjunction with flatfish. This is due to the abusiveness of flatfish skin. What drives the impetus to discard non-roe rock sole and other species in the rock sole fishery is the derby nature of the fishery and the sheer magnitude of price differentials for the species in the flatfish complex that are taken while target-ing rock sole (Table 1). Prices for non-roe rock sole can be as little as one-third to one-fourth that of roe rock sole and Pacific cod is generally less than half the price of roe rock sole. Rock Sole Industry Initiatives to Decrease Dis-card in the Fishery Table 1: Wholesale prices for species landed in the rock sole fishery, FOB Dutch harbor Species Price roe rock sole 1.05 rock sole (S-L) 0.40 Pacific cod (H+G) 0.55 pollock (H+G #2) 0.25 Alaska plaice 0.25 flathead sole 0.45 yellowfin sole 0.25 (average wholesale prices from industry data) Mesh Size A potential means of increasing the retention percentage in the fishery is to increase codend mesh size so that at least more of the small rock sole and other groundfish escape through the net webbing. Some of these fish would presumably survive. If increased net mesh works to allow unwanted fish to escape, this would make the percentage of roe rock sole in the catch greater. In July of 1994, industry requested that the North Pacific Fishery Management Council (NPFMC) develop regulations to require a six inch square mesh panel in the top portion of net codends. According to an industi^ survey, most rock sole fishing currently occurs with codend mesh openings of four to five inches and codends are mostly double-walled. Double-walled codends further restrict the size of net mesh openings. If larger mesh serves to avoid catches that will later be discarded, then it is logical to ask why the fishing industry would not have already increased the size of the mesh voluntarily. The answer is that an unfortunate side effect of existing regulations designed to control bycatch under the Vessel Incentive Program (VIP) set standards of prohibited species (PSCs) catch rates in terms of percentages of total weight caught. This means, for instance, that the halibut VIP rate which could trigger a violation is based on the number of halibut per ton of total catch, not retained catch. Assuming the same number of halibut per tow, a fishing operation that excluded catches of small fish by using larger mesh could be in violation because the actual halibut rate might exceed the VIP standard rate. Had the larger mesh codend not been used, the same tow might not have been in violation. Under this regulatory regime, small rock sole and other fish thus serve as ballast and any change in mesh would have to be accom-panied by a change in VIP standard rate. In December of 1994, the North Pacific Fishery Management Council approved the increase in mesh size for the rock sole fishery but this change, assuming prompt consideration and approval by the Secretary of Commerce, cannot be in place for the upcoming fishery in the winter/spring of 1995. In spite of this, many members of the rock sole fishery appear willing to increase mesh size to six inches throughout their codends without a regulation in place and lacking a change in the VIP standard rate. This could result is a dramatic increase in VIP viol-ations if cases are prosecuted. Some in the industry see the move to larger mesh nets as the one of the few available avenues for the fishery to reduce its discards and therefore improve its public image given the current regulatory regime. 26 Prcjposed Industry Initiative to Increase Retention Another means of increasing retention in the fishery is to retain more of the catch that is currently being discarded. This could be done on a voluntary basis to respond to public criti-cism of "waste" in the rock sole fishery. In September of 1994, rock sole fishermen agreed upon an industry-wide rock sole initiative to increase retention in the fishery by thirty percent in 1995. Several rock sole participants have stated that thirty percent is probably the maxi-mum increase in retention that is possible in the short run given the economic conditions facing the industry and the expectation of continued open-access management. Lack of defined individual allocations under open access continues the race for fish which creates the incentives to fish as fast as possible. This means that fish of lesser value cannot be pro-cessed economically because the fishery is driven to process as much of the high-value product before one of the PSC caps is met and the fishery closes. Some of the economic effects of this proposal to increase retention under the Olympic fishery are evaluated below. Seen on a per trip basis, increasing retention by thirty percent would have large effects on the exvessel trip revenue and possibly make the fishing unprofitable for marginal participants. Assuming that a typical vessel has a freezer capacity of 300,000 pounds of processed prod-uct, the goal of increasing retention by 30% would mean that a vessel would, on average, have to increase its retention percentage from 35% to 46%, an net increase in retention of 11%." If a vessel retained only roe rock sole before, on a 300,000 trip approximately 33,000 pounds of non-roe rock sole would have to be processed and retained. On a first wholesale basis ("freight on board" (FOB) Dutch Harbor), if a firm decided to retain Pacific cod, a logical choice given its price relative to other candidates, then the gross revenue loss of approximately $0.50 per pound would occur for every pound of processed cod retained . This is based on an average first wholesale (headed and gutted) cod price of $0.55 and an average roe rock sole price of $1.05 for frozen (round, ungraded) product. Under these assumptions, gross revenue would decrease by $16,500 per trip. Assuming there are 25 vessels fishing next year and that each vessel make two or three trips during the roe season, the loss of gross revenue that can be expected from the industry initiative is approximately $825,000 to $1.23 million for the rock sole roe season. Proportionally larger decreases in gross revenue could be expected for every unit increase in percentage retention beyond 46% that the indus-try has proposed. This is because fishing oper-ations will first select the fish that have the value closest to that of roe rock sole. If cod are the most likely to be retained, then the cod with the highest value will be retained first. Next cod damaged by contact with flatfish would be a candidate, or other flatfish species that command relatively high prices to minimize the loss of revenue to the vessel. If the retention percen-tage were significantly increased, then small rock sole without roe will have to be retained and effects this would have on revenue losses would be very significant. The impacts of increasing retention would have on the rock sole fleet should not be viewed in a vacuum because many vessels are at or just above the break even point at this time. To appreciate the effects of such a decrease in gross revenue, one has to understand that catcher/processors typically fish in high volume, low profit margin fisheries. Vessels work on tight profit margins because fishing in the Bering Sea involves high fishing costs due to the remoteness of operations, large travel distances to offload points, fishing conditions that are harsh and expensive, and what can be described as high variable cost structures of at-sea pro-cessing operations in general. The Potential Benefits of Increased Retention in the Rock Sole Fishery The potential benefits of decreasing bycatch and discard can be evaluated in terms of resource conservation, ecosystem effects, con-sumer benefits, and improvement in public perception. In theory, these benefits could be realized if the percent retained in the fishery is increased or fishing methods are better able to target roe rock sole so that bycatches do not occur. 27 Although expectations for these types of benefits are reasonable, in the particular case of the rock sole fishery, and other North Pacific fisheries where exploitation rates are very low, whether there are biological benefits from decreasing bycatch and discard is debatable. There may be ecosystem effects but whether these would be positive or negative depends on how criteria are defined and whether exploitation rates that currently occur from the rock sole fishery sig-nificantly impact fish stocks at all. Overall, the main benefit of increased retention or improved targeting of roe rock sole is likely to be improved public image for the rock sole fishery. This is because fishing mortalities overall on rock sole and the other species bycaught in the fishery are extremely low and there are probably no tangible stock conservation benefits to improving the ability to target female rock sole from male rock sole or other members of the flatfish and roundfish species complex. The effective annual exploitation rate on the rock sole population is less than four percent and the population has been growing steadily over the last decade (Figures 1 +2). The same is true for other flatfish that comprise most of the bycatch in the fishery such as flathead sole, yellowfin sole, rex sole, and Alaska plaice according to stock assessments (USDOC, 1994). The biomass increase in recent years for rock sole is slightly more dramatic than has occurred for yellowfin sole and other flatfish species that are commonly bycaught in the rock sole fishery, but overall, the biomass of flatfish is thought to be increasing to historically high levels (USDOC, 1994). Exploitation rates for other flatfish are generally similar or lower than that for rock sole (USDOC, 1994). Decreasing catches of prohibited species such as red king crab and halibut affect the amount of target catch that can be produced in the rock sole fishery but probably have no tangible effect on crab and halibut stocks. This is because halibut and crab PSC caps are very low in terms of the percentage of the biomass that the cap com-prises. For red king crab, for instance, the red king crab PSC limit for the rock sole fishery represents less than one-fourth of one percent of the red king crab population (population size as of 1994). Fluctuation in crab stocks affects this percentage but caps are designed to be a small fraction of the biomass, and in essence, and percentage that is a fraction of the measurement error in the assessment of stock biomass (see NPFMC, 1992). Pollock and cod are the principle round fish bycaught in the rock sole fishery. A large increase in biomass has occurred for Pacific cod in recent years and the status of the pollock stock is thought to be excellent (USDOC, 1994). Fishing mortality on cod and pollock that results from the rock sole fishery is only a small per-centage of overall mortality on these species. As is the case for all fishery management in the North Pacific, the mortality from the rock sole fishery is accounted for when allowable biologi-cal catch (ABC) and total allowable catch (TAC) limits are set for these species. So there is little in the way of a biological evidence that fish stocks bycaught in the rock sole fishery would be in better health if bycatch were reduced or eliminated in the rock sole fishery. One could argue that consumers forfeit the available source of edible protein when bycatch is discarded and hence not brought to the con-sumer. This argument, however, must first recognize that only a portion of these bycatches are on adult fish of market size, i.e. of a size that consumers would be willing to eat. Where bycatch is of juveniles of commercially import-ant species, the impact on consumers, the fishing industry, and value from the nation's natural resources as a whole must be evaluated as the discounted future revenues from those fish, and after the effects of natural mortality are accounted for. This is particularly true when the resource is healthy, as is the case for the bycatch species in the rock sole fishery because future stock conditions are not jeopardized by removals as bycatch or as directed fishing. In the North Pacific, allowable fishing levels take into account both directed fishing and bycatch. Another consideration in assessing the value of fish taken as bycatch versus taken by directed fishing is that, just like mandating high levels of retention, avoiding bycatch is not without costs to the efficiency of fishing operations. Analyti-cally, the cost of avoiding bycatch must be compared to the net future benefits (i.e. dis-counted at some relevant discount rate) from juvenile fish to understand the tradeoffs fully. This cost benefit comparison would also involve the effects of natural mortality on the future 28 benefit of juvenile fish over the interim period. When overall fishing mortality is low and stocks are increasing, removals of juvenile fish bycaught in the rock sole fishery may have little measurable effect on stock conditions. Yet avoiding capturing those juvenile fish is expens-ive. If this were not the case, then the fishing operation would have done so in the first place. When unwanted catches occur, fishing operations incur the cost of sorting and discarding which involves time and labor costs. When evaluating the effects of regulations or initiatives that require increased utilization of the catch, another consideration is that in many cases, it would cost more to the fishing operation to produce something out of these catches than the catches themselves could be sold for. This would likely be the case for skates, rays, sharks, or cod and pollock that are damaged because they are brought up in the codend with flatfish. In this case, operating losses from mandating utilization of non-economic species and damaged fish would have to be passed on to the products that are produced, i.e. higher prices and poten-tial losses of consumer benefit. For adult cod and pollock that are not damaged, and for the flatfish species for which markets exist but price differentials tend to motivate discard rather than retention in the rock sole fishery, fishing operations may be able to pro-cess and retain these catches without incurring deadweight losses. The loss in this case is the opportunity cost of sacrificed rock sole with roe earnings Compared to lower earnings through retention and processing of lower-valued species. Devoting limited hold space to other species when the roe season lasts approximately six weeks could impose large profit losses for some operations. From the perspective of economics, regulations that require increased retention are mandate reduced profits are difficult to justify where measurable biological benefits are not created, or those biological benefits created are negligible. One could argue that consumer benefits and tax basis would be created if these species are produced for the domestic market. On the other hand, consumer benefits and tax basis are created from export earnings when companies that produce roe rock sole are allowed to maximize profits. Profits are taxable and export earnings are recirculated through the domestic economy. Concluding Thoughts Fishing companies that participate in the rock sole fishery have volunteered to increase reten-tion by 30% for the coming season. This may not satisfy public perceptions but, according to the industry, this is a considerable first step considering the inherent tradeoffs and the econ-omic health of the industry. An important consideration is that lack a concrete model to systematically compare economic losses to benefits of increased retention in the fishery. A defined objective that clarifies why bycatch and discard are a consideration when fishing exploi-tation rates are so low is also lacking. A careful, stepwise approach is probably warranted under these circumstances, rather than an emo-tional approach that seeks to "solve" the problem in a very short period of time. For instance, a measured approach might evaluate available evidence of economic performance in the fishery as retention standards or bycatch restrictions are gradually increased. A reasonable schedule of increases in retention known to industry participants in advance could facilitate this transition by allowing the gradual development of markets for lower-value species or allowing participants with a less ability to process and market low margin species to find other fishing or business opportunities. Such a measured approach would at least minimize economic disruptions should policy makers conclude that retention is a more important objective than economic performance, employ-ment, export earnings, and other economic factors. A potential long run solution that would increase the ability to utilize low-valued species under an increased retention standard is to slow the race for fish that currently occurs in the roe rock sole fishery. Some critics contend that mandating retention will already slow the fishery down, but that approach does so at a maximum cost to economic efficiency. A more reasonable approach would be to break the incentives to race for fish by allocating individual fishing allotments of prohibited species catches for halibut and crab SDecies. This would allow 29 individual fishing operations to fish at a pace that is better able to avoid prohibited species catches. This approach provides a means of avoiding the impetus to fish as fast as possible before the total prohibited species cap is met and the: fishery closes, as currently occurs. With individual allotments of bycatch of PSCs, operations may be able to slow down there fishing pace and not incur the costs created by the externality of being affected by other fishery participants' bycatch behavior in the face of a total overall cap for the fishery. Loss of rev-enue from a premature closure of the rock sole fishery by other fishing operations would no longer be a possibility because the costs of fishing indiscriminately would be internalized by fishing operations that cannot fish cleanly, rather than externalized to the whole fleet. With individual bycatch allotments, firms may be able to adjust to a higher retention standard with far less economic cost to the industry and the nation than if the retention standard alone was required. Individual bycatch quotas have been attempted in the high seas purse seine fishery for yellowfin and skipjack tuna with some success. That program has accomplished some individual accountability and allowed fishermen to make adjustments in fishing practices without facing externalities of a fleet-wide closure as a total cap is attained. That approach has also effectively removed the worst offenders in terms of bycatch from the fishery. A controversial but potentially promising means of making individual bycatch quotas effective for rock sole would be to make quotas tradable. Such a system could allow more target catch per unit of bycatch or perhaps the same directed catch with far less bycatch. Both of these are economically efficient outcomes. The mechan-ism that allows achievement of improved utiliz-ation efficiently is a market for bycatch shares. Such a market would tend to allocate rights to those who fish with lower bycatch rates because those individuals would be able to catch more directed catch per unit of bycatch. Thus trading bycatch shares would allow bycatch units to flow to those who make best economic use of the bycatch. Some environmental groups oppose this approach as a potential solution because they believe rights would flow to entities with high bycatch rates and a greater ability to pay for bycatch rights. This argument ignores the fact that, in the long run, firms that catch lower amounts of target catch per unit of bycatch will be unprofitable and exit the fishery. The willingness to pay for bycatch rights by firms that fish cleanly will represent a huge opportunity cost for rights held initially by firms that cannot fish with low bycatch rates. Markets to efficiently allocate effluent rights are currently being used in regulation of pollution in the manufacturing industry. Experience with that approach may some day convince environ-mental groups of the merits of market-based approaches to environmental and resource man-agement. REFERENCES Natural Resource Consultants. 1994. A Global Assessment of Fisheries Bycatch and Discard (Final Report). Dayton Alverson, editor. Unpublished manuscript. Seattle, Washington. Pacific Associates. 1994. Discards in the Groundfish Fisheries of the Bering Sea / Aleutian Islands & the Gulf of Alaska Dur-ing 1993. A report prepared for the Alaska Department of fish and Game. Unpublished manuscript. Juneau, AK. U.S. Department of Commerce, NOAA, NMFS. 1994. Stock Assessment and Fishery Evalu-ation for the Groundfish Resources of the Bering Sea/ Aleutian Islands Regions as Projected in 1994. Alaska Fisheries Science Center, Seattle, WA North Pacific Fishery Management Council. 1992. Amendment 12A to the Fishery Management Plan for Bering Sea and Aleutian Islands Groundfish (Prohibited Species Caps). Anchorage, AK. 30 FIGURE 1: Eastern Bering Sea Rock Sole biomass trends 1975-1994 ?survey biomass (?synthesis biomass 1075 1977 1079 1981 1993 1995 1987 1999 1991 1993 1995 source:N .M.F .S . 1 9 9 5 "Stock Assessment and Fishery Evaluation" ( S A F E ) Repor t Figure 2. EXPLOITATION RATE FOR ROCK SOLE IN THE EASTERN BERING SEA Thotamtta nole actual catch of rock sole is less than 3% of the estimated biomass in 1994. Rock sole TAC is set at a low level because of the 2 million metric ton(ecosystem) cap on BS/AI removals and the industry's preference lot pollock 2500 2000 1500 1000 f 500 actual eaten ? t o t . alow, catch biomass metric ton* souica NMFS SAFE Repent. NMFS Final Specifications Iof tha Groundfish Fisheries oI Itie Sating Sea Aleutian Islands (1994) SECTION II BYCATCHES AND TRAWL FISHERIES 31 THE PACIFIC GROUNDFISH TRAWL FISHERY BYCATCH PROBLEMS AND POTENTIAL SOLUTIONS Barry Ackerman, Department of Fisheries and Oceans, Groundfish Management Unit, Stn. 418, 555 W. Hastings St., Vancouver, B.C. V6B 5G3, Canada. ABSTRACT Bycatch has been a growing problem in trawl fisheries for more than a decade. The problem is a result of the non-selectivity of trawl gear, the attitude of fishermen regarding bycatch, and the regulations employed to manage the fishery. The Pacific groundfish trawl fishery is one of the most regulated fisheries in Canada. In an effort to manage to prescribed species TAC's, restric-tions have been implemented which limit the catch per trip and the number of permitted trips. These measures have, unfortunately, lead to increased fishing effort and further bycatch and discarding problems. The following presentation looks briefly at the development of the Pacific groundfish trawl fishery, associated bycatch and discarding problems, and discusses management options for remediation. ? ? ? RESEARCH AND DEVELOPMENT EFFORT IN BY-CATCH ELIMINATION IN TRAWL FISHERIES OF BRITISH COLUMBIA Douglas March, Deep Sea Trawlers Associ-ation of BC., Unit 2, 11771 Horseshoe Way, Richmond, B.C. V7A 4V4, Canada. ? ? ? The Deep Sea Trawlers Association was formed in 1980 as a consequence of problems and changes in the trawling industry. As the industry progressed, our Association had to take different lines and different points of view. The real crunch came in the late 1980s and particularly in 1990 when the Department of Fisheries and Oceans (DFO) introduced new regulations and trip limits which made it really difficult to go fishing rockfish. Until this time, more than 30 species of rockfish were fished and if they were red fish, they were put all together in one bin. But as a result of these regulations, this was no longer possible. The Association was at a loss what to do and in 1990 put a think-tank together which included personnel from the higher eche-lons of DFO, major BC fish processors and other major players in the industry to try and come up with some solution to deal with the DFO management plan. The result of this think-tank was the recognised need for the Association and it members to participate in the development of management plans for the fishery and to con-tribute their expertise. In 1991 the Association adopted the position whereby the fishery should have a sustainable yield and operation of trawlers, it should be economically viable and environmentally clean. And that's tough: any-body that's been a fisherman knows that that's tough. After the think-tank, we organised a Gear Sel-ectivity Workshop. Out of the workshop we put a technical group together, again Processors, DFO, Ministry of Agriculture Fisheries and Food, the Union and the Association were represented. It was recognised that for there to be a viable trawling industry by-catch had to be reduced and as far as possible eliminated. By-catch of halibut was identified as a major prob-lem, the trawl fishery causing major mortality of halibut. We do catch halibut and we do have to 40 Videophotography revealed that fish in the Paulegro trawl codend appeared agitated and were continuously showered with sediment and debris raised by the bobbin line. In contrast, fish in the semi-pelagic trawl codend were swimming with the net; the plume of sediment and the sound of the ground tackle moving over the substrate was greatly reduced. The semi-pelagic trawl is considered commer-cially viable in the trawl fishery in the Arafura Sea, as evidenced by the similar catch rates and sizes of the targeted snappers in both trawls, and comparable production costs. The semi-pelagic trawi also enhances product quality by reducing the unwanted catch of fish, benthos and debris, and environmental disturbance was significantly less than that of the Paulegro net due to much reduced impact on the substrate, damage to the benthos and catch of unwanted components. While our analysis of catch data could not detect the shearing and dislodging of benthic structures by the sweeps, videophotography of the semi-pelagic trawl footrope showed no such damage even at the point closest to the substrate (0.3 m off the bottom). We conclude that this type of semi-pelagic trawl is "environmentally friendly" and commercially viable in the tropical snapper trawl fishery off northern Australia. Further research on by-catch reduction is now underway to improve the selectivity and efficiency of ground trawls (e.g. Mounsey et al, 1994; Ramm and Xiao, submitted). ACKNOWLEDGMENTS We gratefully acknowledge the assistance of Graham Baulch, Christine Julius, Alf Mikolaczyk (Fisheries Division), Tracy Hay (International Food Institute of Queensland), and Jon Abbey and the crew of the FV "Clipper Bird" (A.Raptis & Sons). This study was sup-ported, in part, by the former Australian Fish-eries Service (Tnist Account 1990-91). SELECTED REFERENCES Mounsey, R.P., Baulch, G.A., and Buckworth, R. C. (1994). Development of a trawl efficiency device (TED) for Australian prawn fisheries. I. The AusTED design. Fisheries Research 00, 000-000. Sainsbury, K.J., 1987. Assessment and manage-ment of the demersal fishery on the continental shelf of northwestern Austra-lia. In: J.J. Polovina and S. Ralston (Editors), Tropical Snappers and Groupers. Biology and Fishery Manage-ment. Westview Press/Boulder and London, pp.465- 503. Maucorps, A. and Portier, M., 1971. Le chalutage semi-p6Iagique pour la peche du hareng. In: H. Kristjonsson (ed.), Modern Fishing Gear of the World: 3. Fishing News (Books) Ltd, London, pp.467-471. SECTION III BYCATCHES AND PASSIVE GEAR FISHERIES 41 WORLD BYCATCHES OF SHARKS IN HIGH-SEAS FISHERIES: APPRAISING THE WASTE OF A RESOURCE Ramon Bonfil, Fisheries Centre, University of British Columbia, 2204 Main Mall, Vancouver, B.C. V6T IZ4, Canada ABSTRACT Estimates of bycatches of sharks in each of the major high-seas fisheries of the world are pres-ented for the first time. Although necessarily rough due to generally poor baseline informa-tion, present estimates indicate that sharks are the leading bycatch in this type of fisheries. The total bycatch of sharks and relatives in these fisheries amounted to about 11.6-12.7 million fish or 260-300 thousand t per annum during the late 80's-early 90's. The most important sources of the problem are first the long-line fisheries for tunas and billfishes and secondly the recently banned high-seas driftnet fisheries for various species. Other less important sources of shark bycatches are purse-seine and pole-and-line fisheries for tunas, and the orange roughy fish-eries around New Zealand. Estimates of the levels of discard from all these fisheries are also very high. The impacts of such removal rates on shark populations, as well as other problems of shark-fisheries interactions are discussed. ? ? ? INTRODUCTION Several large-scale fisheries operating in the high seas around the world are known to capture elasmobranchs, particularly sharks, as a substan-tial by-catch. Although sharks are retained and utilized in some of these fisheries, most fre-quently they are simply thrown overboard, sometimes after having had their valuable fins chopped off, and discarded to an almost certain death. The amount of elasmobranchs killed in large-scale high seas fisheries is poorly understood and has not been systematically assessed. Reports on the sharks taken by the countries involved in these fisheries do not reflect the real incidental by-catches but most frequently only the amounts retained. The purpose of this paper is to present for the first time a global assessment of elasmobranch by-catches in the most important high-seas fisheries of the world, the amounts taken and the total discards. The main fisheries analysed were: -Drift gillnet fisheries North Pacific Ocean Salmon fishery Flying squid fishery Tuna/billfish Large-mesh driftnet fish-ery (LMDF) South Pacific Ocean LMDF Indian Ocean LMDF Atlantic Ocean LMDF -Longline fisheries Atlantic Ocean Indian Ocean Tropical and South Pacific North Pacific -Purse seine fisheries for Tunas Worldwide -New Zealand Orange Roughy fishery All other fisheries which incidentally capture elasmobranchs were considered to either include their elasmobranch catches in their official statistics, or their by-catches to be effectively negligible. DATA SOURCES Most of the information presented here came from reports of the International North Pacific Fisheries Commision (INPFC), the International 42 Commission for the Conservation of Atlantic Tunas (ICCAT), the Inter American Tropical Tuna Commission (IATTC), the Indo Pacific Tuna Development and Management Programme (IPTP), and other international bodies. Incidental catches were estimated where no estimates already existed and were then compared with reported landings for each fishery or country in order to assess the quantities of elasmobranchs wasted each year and not included in the official statistics of world fisheries. Reported catch rates were extrapolated to the total effort/catch of each fishery, although in some cases it was proportion of sharks in the catch that was extrapolated to the total catches. ESTIMATES OF SHARK BYCATCHES Before their demise at the end of 1992, follow-ing UN resolution 44/225, high-seas driftnet fisheries were a very important source of elasmobranch by-catches. Total elasmobranch by-catch could have been between 3.28 and 4.31 million sharks and rays per year during 1989-1991, or in the order of 20,000-38,000 t/year. Total discards of elasmobranchs at sea from driftnet fisheries could have been between 20,803 and 30,500 t/year. High-seas longline fisheries for tunas and billfishes are a very large source of by-catches and discards of elasmobranchs worldwide. Despite the uncertainty surrounding the different estimations, it is nonetheless evident that the amount of effort exerted by longlining fleets (worldwide total of about 750 million hooks) is the main reason for the high by-catch estimates. The grand total of elasmobranchs caught incidentally by longlining fleets in all the high-seas of the world is estimated at almost 8.3 million fishes or an astonishing 232,425 mt. This represents almost a third of the total world catch of elasmobranchs reported in commercial fish-eries by FAO in 1991. The level of by-catches of blue sharks in longline fisheries is very large. Present estimates suggest a total of 4*075,162 blue sharks caught incidentally in the high-seas longline fisheries of the world. The estimated total catch of sharks in purse seine fisheries during 1989 is of 6,345 t. This esti-mate is very uncertain as it was based on a single (and poorly representative) account of shark catch rates in tuna purse seine operations in the Western Indian Ocean. The accuracy and precision of the assessment will only improve when more information on catch rates becomes available and as our understanding of the sea-sonal and spatial changes in the shark-tuna associations increases. Pole and line fisheries for tunas take some shark by-catches while fishing tuna schools. However, they are very poorly documented and no assess-ment was possible. It is likely, due to the global scale of pole and line fisheries for tunas that their by-catch of sharks could sum to a signifi-cant total, perhaps in the order of magnitude of that from purse seiners. The orange roughy (Hoplostethus atlanticus) fishery of New Zealand is known to take deep water squaloid sharks and other elasmobranchs in their bottom trawl nets. Based on research surveys for orange roughy, the total by-catch of squaloid sharks could be between 4,400 and 22,000 t/y in this fishery. The current catches exceed by far the MSY estimated by New Zea-land researchers. The impact of this level of by-catch on the local stocks of deep-sea sharks is poorly known.but it is highly unlikely to lead to sustainable exploitation. However, this is diffi-cult to verify when there is virtually no informa-tion about the actual levels of by-catch, survival of discards and about the popualtion dynamics of these deep water sharks. The estimated grand total of elasmobranch by-catch from all high-seas fisheries considered here at the end of the 1980's, is believed to be around 260,000 and 300,0001 or 11.6-12.7 million fish per year. Most of these catches were sharks, predominantly blue sharks. Discards from high-seas fisheries also appear to be very high. The figures suggest that up to 230,000-240,000 t of elasmobranchs are dis-carded every year in the various high-seas fisheries. The fate of most of the discards is probably death, almost certainly for those caught by the driftnet, purse seine and orange roughy fisheries. For longline fisheries, survival depends on whether fishermen release sharks readily and unharmed. Nevertheless, common finning prac-tices make dubious that survival is high in longline operations. 43 DISCUSSION Longline fisheries are the most important source of shark kills in the high-seas, mainly because of the magnitude of their effort. They contribute about 80% of the estimated total eiasmobranch by-catch in weight and about 70% in numbers of fish. There is large uncertainty around the estimations performed for this type of fisheries. However, the figures are based on the best available information and they seem to compare well with the few reference points available. The former high-seas drifitnet fisheries ranked second for their contribution to the total eiasmobranch by-catches. Since their activities were terminated worldwide at the end of 1992, they are now one less problem to worry about in terms of sea-life conservation. Available information on purse seine and pole-and-line tuna fisheries and the deep trawl fish-eries for orange roughy make it very difficult to assess the importance of their by-catches of sharks and rays. Presently, they seem to share a minor part of the total by-catch of elasmobranchs but there is a big gap in direct information on this subject. More, simple research, is needed in this field. There is another substantial source of by-catch and waste of sharks and rays around the world. This is the incidental catch of bottom trawling vessels fishing for shrimps and fishes in conti-nental shelves. The assessment of the impact of these fisheries upon elasmobranchs is out of the scope of this work primarily because of the extreme difficulty in gathering information about them and the magnitude of this quest. In contrast with drifitnet fisheries, there is no observer programme for any of the high-seas longline fisheries in the world. This accounts for much of the uncertainty surrounding the esti-mates of non-target species caught in longline fisheries. It is worth noting that most of the international tuna organizations and the govern-ments of longline fishing nations mandating logbook reports from longliner fleets, still do not require or enforce the reporting of by-catches of sharks or other elasmobranchs. Some of these organizations are taking steps to change this situation. This should help reduce the uncertainty about the real levels of by-catches and discards in the near future. Considering the common underreporting of elasmobranchs in longliner logbooks, observer programmes are undoubtedly the best way to tackle this crucial information problem. A total estimation of elasmobranchs caught and discarded in high-seas fisheries worldwide is problematic when neither of these processes are adequately documented. Discard rates and con-current survival rates are virtually unknown. There are large uncertainties about the catch rates that should be applied to each region and sometimes also about the effort levels. Addi-tionally, the estimates presented here are derived from the sum of estimates for each fishery and consequently carries along a good degree of accumulated uncertainty. We should expect qualitative and quantitative variations in the eiasmobranch by-catches within each ocean due to areal and seasonal changes in availability of the different species. Unfortunately, these sources of variability could not be taken into account in the present work with the available information. In this sense results presented here should be treated with discretion and used only as a first approximation of the level of elasmobranchs removed by high-seas fisheries worldwide. They do however highlight the problems found when trying to assess the magni-tude of the eiasmobranch by-catch and the proportions dumped to the sea. CONSERVATION PROBLEMS Blue sharks are the most common eiasmobranch caught incidentally in high-seas fisheries. Present estimates are that 6.2-6.5 million blue sharks are taken annually worldwide in these fisheries. Although this is apparently the first estimate of total catches for blue sharks in all high-seas fisheries of the world, the assessment of blue shark by-catch presented here seems to be within values found for specific fisheries reported elsewhere. Our current level of knowledge prevents an assessment of the impact that the removal of 6 million blue sharks annually has on high-seas ecosystems or on the blue shark populations. There is virtually nothing known about the size of the stocks of blue sharks anywhere in the 44 world and the biology of most populations is poorly understood. Research is badly needed both to assess the real by-catch levels in each fishery and their impacts on the different popula-tions. Silky sharks are probably the second most commonly caught species, specially in longline and purse seine fisheries. As for blue sharks, appropriate information is lacking to assess the impacts of the removal levels. In any case, their characteristics of growth and reproduction compare poorly to those of blue sharks, i.e. silky sharks have slower growth, later sexual maturation and are much less fecund. Hence, they are expected to be less resilient to exploita-tion than blue sharks. Again, much research is needed before it is possible to draw conclusive statements in this field. Local stocks of Deania calcea, Etmopterus baxteri and Centroscymnus spp. in New Zealand could be added to the list of elasmobranchs under possible threat by large-scale fisheries. World catches of elasmobranchs are substantially higher than reflected by the different kinds of official statistics. Statistics reported to FAO amount to just below 700,000 t for 1991. The results presented here suggest that the total catch (as opposed to landings) could be closer to 1 million t. If we add to this the bycatches in bottom trawl fisheries in coastal areas and the recreational catch of elasmobranchs, the real total level of sharks, rays and chimaeras caught around the world is probably closer to 1.35 million t or more per year, twice the official statistics. The by-catch of elasmobranchs in high-seas fisheries around the world seem to be a major source of concern for conservation due to the very high numbers of sharks killed. Blue sharks in particular might be facing extreme pressure in many parts of the globe because of these fish-eries, but more specific studies are needed in order to address the real situation. A possible way to solve this dual problem could be to install shark deterrent devices in passive fishing gears (these account for most of the elasmobranch kill). The Natal Shark Board in South Africa is currently testing a promising electroacoustic device to protect bathers from shark attacks without having to kill the sharks. Another possibility would be to design new selective fishing gear that could substantially reduce shark hooking rates. However, for the time being the only viable alternative is the implementation of suitable by-catch quotas for elasmobranchs in the high-seas fisheries of the world through international agreement, and their reinforcement via observer programmes. (Note from the editors: a full version of this paper can be found in F.A.O. Fisheries Techni-cal Paper 341, F.A.O., Rome, 1994). The possible threat that high-seas fisheries pose to elasmobranchs is actually only one part of a complex technical interaction. There is substan-tial gear and catch damage caused by sharks in most of these fisheries and this translates directly into economic loss for the fishing industries. 45 MANAGEMENT OF BYCATCH IN HOOK-AND-LINE GROUNDFISH FISHERIES OFF ALASKA Janet Smoker, Fisheries Information Services (FIS) , 20007 Cohen Drive, Juneau, AK 99801, USA ABSTRACT In 1993, hook-and-line gear took 90% of sablefish, 34% of Pacific cod, and 86% of Greenland turbot in the EEZ off Alaska. The principal bycatch species is halibut; negligible numbers of crab, salmon, or herring are taken. In the Bering Sea and Aleutian Islands (BSAI) area 13% of total groundfish-fishery-induced halibut mortality was from hook-and-line gear, and in the Gulf, 41%. Several different approaches to reduce such halibut mortality have been made in the last few years: setting halibut caps, setting seasons for target species and cap apportionments, and requiring careful release of halibut. In 1993 the Gulf Plan Team recommended the following as general methods to control bycatch: incentive programs, timing of groundfish seasons, and seasonal apportionment of halibut PSC limits. The Team also suggested that license limitations would reduce halibut catch. Other non-regulatory approaches have been taken recently to provide information to fishermen to help lower bycatches. During 1994 the catcher/processor fleet has supported a private effort to monitor and avoid halibut "hot spots". Also in 1994 historical hook-and-line observer data (1979-1992) was developed into a series which maps catch and bycatch by time and area strata. For future attention: How much will sablefish ITQ program reduce bycatch - and how will we know? How effective has "careful release" regulation been, and can it be improved? Are there other time/area closure approaches that can have some positive effect? ? ? ? Hook-and-line fisheries off Alaska target on groundfish species including Pacific cod, sablefish, Greenland turbot and rockfish (Fig. 1)! The chief bycatch species is Pacific halibut, which may not be retained in groundfish fish-eries. Concern for traditional fisheries for halibut has prompted the North Pacific Fisheries Management Council (NPFMC) to impose halibut mortality "caps" which close a target groundfish fishery if reached. To avoid reaching these caps, or at least to maximize the catch of target groundfish species before closure, both regulatory agencies and industry have imple-mented several approaches in recent years. Hook-and-line fisheries in the Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BSAI) management areas have had very different histories, so the halibut bycatch management approaches have varied in timing and detail between the two areas. Gulf of Alaska Halibut Bycatch Reduction Methods In the GOA, the hook-and-line sablefish fishery (with recent annual quotas of around 20 000 mt) was the first Alaska groundfish fishery to become "Americanized" after enactment of the Magnuson Fishery Management and Conserva-tion Act of 1976. Later, Pacific cod became a target both for catcher/processors and for smaller boats delivering shoreside, with a 1993 catch of about 9 000 mt. In the Southeastern area of the GOA, a small (under 1 000 mt) state-managed fishery for demersal shelf rockfish occurs. The 1993 ex-vessel value of all these fisheries was $52 million. In 1993, hook-and-line gear caused 1 289 mt of halibut mortality or 41 % of the GOA total (Fig. 2). The first GOA halibut cap was imposed in 1990; this cap (740 mt) was later seasonally apportioned into trimesters to allow for a winter fishery for Pacific cod and a spring fishery for sablefish. The only cap specifically imposed for a target fishery is for demersal shelf rockfish, which in 1992 was given its own cap of 10 mt. In 1991, the sablefish season was delayed to begin May 15 instead of April 15, in order to let halibut migrate out of deeper waters where sablefish are caught. In 1993 the hook-and-line fleet exceeded its cap by 85% due to higher than 46 expected bycatch rates in the sablefish fishery. Much of the high bycatch can be attributed to huge effort during the short (one to two weeks in most areas) season, which results in many vessels being displaced into shallower areas where more halibut are present. One of the expected benefits of the sablefish and halibut Individual Fishing Quota program, to be imple-mented in 1995, is that the extended season will alleviate such crowding and halibut discards will decrease. Bering Sea/Aleutian Islands Halibut Reduction Methods. In the BSAI, hook-and-line activity has increased dramatically with the growth of the catcher/processor fleet. Hook-and-line Pacific cod catch increased from 14 219 mt in 1989 to 101 249 mt in 1992. The trawl fishery for Greenland turbot had been closed in 1992 and 1993 due to its extremely high halibut bycatch rates, and hook-and-line gear took advantage of the niche: its catch increased from 1 130 mt to 7 086 mt. The sablefish target fishery, pursued mostly along the Aleutian Island chain, has remained fairly stable (2 648 mt in 1993); it has been unable to expand in part because of gear-stripping by killer whales. Total ex-vessel value of all BSAI targets in 1993 was $38 million. In the BSAI area in 1993, 13% of total groundfish-fishery-induced halibut mortality was from hook-and-line gear (Fig. 2). Responding to the rapid growth of BSAI fixed gear fisheries, NPFMC imposed a a halibut cap in 1992 which was then divided between the Pacific cod target (680 mt) and all other fixed gear fisheries (220 mt). In 1994 NPFMC divided the fixed gear Pacific cod quota (45% of total allowable catch) seasonally to provide a winter and fall fishery and to avoid high halibut bycatch rates encoun-tered in late spring and summer. Other Halibut Bycatch Reduction Measures Common to both the BSAI and GOA is a regula-tion implemented in 1993 which requires careful release of halibut from fixed gear. (An industry-sponsored program promoting careful release was carried out in 1992). The International Pacific Halibut Commission (IPHC) analyzes halibut mortality information collected by federal observers and recommends rates that are used in mortality calculations each year. In these calcu-lations, non-observed boats are given a higher assumed mortality rate than observed boats. Following the BSAI Pacific cod spring 1994 season, each observed vessel was informed of its own calculated halibut mortality rate and pro-vided with overall fleet statistics. This has been the first opportunity for fishermen to become aware of the variablity of this key component of halibut bycatch monitoring and to put their own vessel's performance into context. Further analysis is needed to discover why such variabil-ity exists and how mortality rates can be improved. Non-regulatory tools are also being developed to reduce halibut bycatch. During 1994 the catcher/processor Pacific cod fleet has supported a private program to monitor and avoid halibut "hot spots". Set-by-set data collected by federal observers was sent twice-weekly from each participating vessel to FIS, who compiled and mapped the rate information, and returned it to the fleet (Fig. 3). Vessels were able to move from high-rate areas; overall, participants had a spring season bycatch rate about 20% below that of the rest of the fleet. Success of this sort of "micro-management" program is dependent on quick turnaround of data, and its vulnerability was evidenced in the fall season when communi-cation problems interfered with data transfer; this suggests that such programs should not be implemented by regulation unless an absolutely dependable information system is in place. Also in 1994, the Department of Commerce's Saltonstall-Kennedy program supported FIS with a grant to develop historical federal observer catch and bycatch data into a format usable by fishermen and managers. The resultant five-volume series includes maps showing rates (kilograms per hook) for target species and Pacific halibut bycatch, by time (weekly and/or monthly) and area (1/2 degree latitude by 1 degree longitude) strata (Fig. 4). Volumes include BSAI Pacific cod, Greenland turbot and sablefish, and GOA Pacific cod and sablefish. Each volume is further subdivided into foreign and domestic fisheries data sections, reflecting differences in fishing operations and in time (most foreign data are from 1979-1987 and most domestic data are from 1988 to 1992). Fisher-men can use the series to plan where and when to fish in accordance with historical patterns. Fisheries managers can use the series to develop further time/area closures, if appropriate {although this management tool has been mostly used in trawl fisheries to date). Control of halibut bycatch in hook-and-line fisheries off Alaska is effected by a combination of regulatorily-imposed and independently oper-ated programs. Key to the success of both is the proper collection, analysis and prompt dissemi-nation of information to fishermen and managers alike. REFERENCES Economic Status of the Groundfish Fisheries off Alaska. 1993. Kinoshita et al. Alaska Fish-eries Science Center, National Marine Fish-eries Service, 7600 Sand Point Way N.E. Seattle WA 98115-0070. National Marine Fisheries Service, Alaska Region Inseason Reports (NMFS Bulletin Board). Fishermen's Guide to Catch and Bycatch Alaskan Hook-and-Line Fisheries. Parts 1-5. 1994. Fisheries Information Services, 20007 Cohen Drive, Juneau, Alaska 99802. FIG. 1 HOOK-ANO-UNE SHARE OF HALIBUT MORTALITY (MT) FIG.1 SPECIES COMPOSITION HOOK-ANO-UNE CATCH 1993 GOA HALIBUT MORTALITY 1993 SSA1 HALIBUT MORTALITY 49 BYCATCH OF STEELHEAD AND COHO SALMON IN THE SKEENA RIVER SOCKEYE FISHERY Joel Sawada and Art Tautz, British Colum-bia Provincial Fisheries Branch, 2204 Main Mall, Vanvouver, B.C. V6T 1Z4, Canada. ABSTRACT The Skeena River salmon fishery is the second largest salmon fishery in British Columbia and the third largest sockeye salmon (Onchorynchus nerka) fishery in the world. Several user groups harvest the salmon during their migration includ-ing: Alaskan gill net fishermen, British Colum-bia seine boats and gill net boats, the aboriginal food fishery, and sport fishermen. Because of similar migration timings, the sockeye fishery has incidental catches of less productive species, most notably steelhead (O. mykiss) and coho salmon (O. kisutch). Management's goal is to reduce steelhead interception by 50% in three years. A brief history of the management of the fishery is presented as well as the current management's use of a computer simulation model in conjunction with a test fishery. ? ? ? INTRODUCTION The Skeena river is a large system (watershed area 35,000 km2) draining into the Pacific Ocean just south of the British Columbia-Alaska border (see figure 1). In British Columbia, the Skeena is second only to the Fraser River for salmon production and is the third largest sockeye pro-ducer in the world, behind Bristol Bay, Alaska and the Fraser River. It includes 21 major sockeye stocks and 16 steelhead stocks. The number of coho stocks has not been documented but can be estimated at greater than 20. The biology of Skeena river sockeye have been extensively studied (Brett 1952, Larkin and McDonald 1968, Smith and Jordan 1973, Takagi and Smith 1973, McDonald and Hume 1984, West and Larkin 1987). Current and historical management of the Skeena sockeye fishery has been documented in Sproat and Kadowaki (1987). The Skeena has 4 major tributaries: Bulkley, Babine, Kispiox, and Sustut and several smaller tributaries including: Lakelse, Bear, Alastair, Kitwanga and Kitsumkalum. The Babine system and its tributaries currently produce 95% of Skeena river sockeye. Steelhead and coho pro-duction is more evenly distributed between the various tributaries. THE FISHERY Sockeye are the most valuable of the five com-mercially exploited pacific salmonids and the Skeena sockeye fishery is of considerable econ-omic importance. There has been a directed commercial fishery for sockeye on the Skeena since 1877. Catch data start in 1904 and catch and escapement data go back to 1943 (McDonald et al. 1987). Sockeye has always been the prin-ciple target on the Skeena, but by 1920, all species of salmon were fished commercially. Management of the five commercially exploited species is the responsibility of the federal gov-ernment while management of the sport fished steelhead is the responsibility of the provincial government. In 1946 a permanent fish counting fence was completed on the Babine River and in 1955 the test fishery at Tyee was established. Calibrated against the Babine fence count, this test fishery gave a daily estimate of sockeye escapement and formed the basis of a rational in-season manage-ment system. Weekly closed times are varied according to fish abundance and escapement targets. FISHERS There are five different groups catching Skeena river fish as they migrate to their spawning grounds. The fishery starts in Alaska, of which little is known about the exploitation rates. After the fish reach Canadian waters, they are fished by the Seine fleet. The exploitation rate for the Alaskan fishery and for Canadian Areas 1,3, and 5 is assumed to be 25%. Continuing their migration into Statistical Area 4, the fish are harvested by the gill net fleet 15 km into the river. Upstream of this boundary the fish encounter First Nations and recreational fish-eries. The First Nations fishery occurs mostly with gill nets but also occurs by more traditional methods 50 like harvesting using a gaff. The aboriginal fishery is primarily a food fishery, but excess sockeye (overescapement) are allowed to be caught and sold by the First Nations fisherman. The other in river pressure comes from the recreational fishery. The sport fishery for salmon is a kill fishery but the fishery for steelhead is non-consumptive. ENHANCEMENT Beginning in the mid 1960's, 3 spawning chan-nels were built on two tributaries to Babine Lake under the assumption that the lake could support more sockeye juveniles (McDonald and Hume 1984). An increase in sockeye production of between 500,000 and 1,000,000 sockeye per year has been attributed to these three channels. It is interesting to note that the increased produc-tion did not occur until 12 years after these facilities began operation (Hilborn and Winton 1993). BYCATCH The bycatch problem (harvest of non-target species) on the Skeena is due to migration tim-ings of the different species, and different stocks within each species, occurring at the same time (see fig 2). For management purposes the run timing of the different species of fish is often represented as a single distribution. This is incorrect since this distribution includes several different stocks. THE PROBLEM Since 1980, increased fishing effort has occurred to exploit the increased production of Babine sockeye. This increased fishing effort has caused a decrease in less productive sockeye, coho, and steelhead stocks. In 1991, a goal was established by the federal Department of Fisheries and Oceans to decrease steelhead interceptions by 50% within 3 years. The estimate of steelhead exploitation by the federal fishery managers was 36%, the exploitation estimate by the provincial steelhead biologists was 62%. EARLIER EFFORTS Earlier efforts of selective harvest included lowering commercial gill nets 1.2 meters below the weedlines. Initial tests indicated a 60-70% reduction in steelhead catch with a 20-30% reduction in sockeye catch. There have been 2 problems with weedlines; 1) It is not known whether overall steelhead mortality would be reduced to 30-40% or whether each net contrib-utes 30-40% mortality. The fish encounter dozens of nets on their migration. If each net kills 40% of the vulnerable fish, the cumulative mortality is still too high. 2) fishermen feel that a loss of 20-30% of their fish is unacceptable. There has been a policy of voluntary live release of steelhead from gillnets. It belived there is low compliance to this policy and up to 70% mortality for those fish which are released (B. Ward, Ministry of Environment, Lands and Parks, pers comm). The third procedure for selective harvest is seine brailing. This method involves transferring fish from the seine net to the hold using a large dip net rather than bringing the fish on board by the seine drum. It is believed mortality is reduced allowing live release of non-target species. The effect of this practice has yet to be quantified. CURRENT POLICY The current practice is to vary fishing effort over time and space. This can occur at different scales. For example, it is known that coho are most vulnerable at dawn and dusk; not fishing at these times is a possible solution to coho bycatch. The dropping of the nets for steelhead was described earlier. A management model has been developed to account for catch and escapement. The model incorporates the "boxcar" theory; fish pass through a series of fisheries before escapement. Harvest is regulated by varying effort over time and location. The model occurs on a daily time step and calculates catch and escapement past the fishery. It treats statistical Area 4 as four sequential fisheries prior to escapement (see figure 3). We have empirical data about migra-tion rates and timing, catchability in each of the four regions, and the relationship between cpue and number of boats. Some assumptions must be made, it is assumed that 25% exploitation occurs outside area 4, and 6% exploitation 51 occurs in the river due to the first nations and sport fisheries. Other assumptions are for ease of calculation such as uniform distribution of fish within each sub-area and constant speed and direction of fish migration. The model was calibrated to empirical data; using no weedlines and current openings, sockeye harvest is 40% and steelhead harvest is 36%. Eight management options were examined involving presence or absence of weedlines and varying fishing openings over time and space. Three of these options gave the desired result of 50% steelhead reduction and a 40% sockeye har-vest. Common factors were use of weedlines, moving the sockeye harvest earlier in the season and increasing fishing time to account for loss of sockeye due to the weedlines. The model indi-cates the overall goal is attainable however, each species is treated as a single distribution. The model was not designed to account for different stocks so we do not know the effect of these various management policies on individual sockeye, steelhead, or coho stocks. The model is not used in the daily management of the fishery but as an exploration too! to assess the various management options. The best harvest strategy was established before the season started. IN-RIVER FISHERY The First Nations river fishery is being encour-aged to use alternative harvest techniques such as live traps, weirs, and ftshwheels. These methods allow release of non-target species. Currently, few of these alternate fishing methods are in use and gill nets are still the primary means of harvest. FUTURE WORK More work needs to be done on the stock com-ponent of the fishery. Stock identification of steelhead by molecular techniques is currently being performed. Both management agencies are optimistic that the goal of a 50% reduction in steelhead bycatch can be obtained. REFERENCES Brett, J. R. 1952. Skeena River sockeye escape-ment and distribution. J. Fish. Res. Board. Can. 8: 453-468. Cox-Rogers, S. 1994. Description of a daily simulaton model for the Area 4 (Skeena) commercial gillnet fishery. Can. Manuscr. Rep. Fish. Aquat. Sci. 2256: iv +46 p. Hilborn, R. and J. Winton. 1993. Learning to enhance salmon production: lessons form the Salmonid Enhancement Program. Can. J. Fish. Aquat. Sci. 50:2043-2056. Larkin, P.A,, and J. McDonald. 1968. Factors in the population biology of the sockeye salmon of the Skeena River. J. Anim. Ecol. 37:229-258. McDonald, J., and J. M. Hume. 1984. Babine Lake sockeye salmon (Oncorhynchus nerka) enhancement program: testing some major assumptions. Can. J. Fish. Aquat. Sci. 41:70-92. McDonald, P. D. M., H. D. Smith, and L. Jantz. 1987. The utility of Babine Smolt enumerations in management of Babine and other Skeena River sockeye salmon (Oncorhynchus nerka) stocks, p. 280-295. In H. D. Smith, L. Margolis and C.C. Wood [ed.] Sockeye salmon (Oncorhynchus nerka) population biology and future management. Can Spec. Publ. Fish. Aquat. Sci. 96. Smith, H. D. and F. P. Jordan. 1973. Timing of Babine Lake sockeye salmon stocks in the north-coast commercial fishery as shown by several taggings at the Babine counting fence and rates of travel through the Skeena and Babine Rivers, Fish. Res. Board Can. Tech. Rep. 418: 31 p. Sprout, P. E. and R. K. Kadowaki. 1987. Managing the Skeena River sockeye salmon (Oncorhynchus nerka) fishery - the process and the problems, p. 385 - 395. In H. D. Smith, L. Margolis and C.C. Wood [ed.] 52 Sockeye salmon (Oncorhynchus nerka) population biology and future management. Can Spec. Publ. Fish. Aquat. Sci. 96. Takagi, K. and H. D. Smith. 1973. Timing and rate of migration of Babine sockeye stocks through the Skeena and Babine Rivers. Fish. Res. Board Can. Tech. Rep. 419: 61 p. Ward, B.R., A.F. Tautz, S. Cox-Rogers, and R.S. Hooten. 1993. Migration timing and harvest rates of the steelhead trout popula-tions of the Skeena River system. PSARC Working Paper S93-06. West, C.J. and P. A. Larkin. 1987. Evidence for size-selective mortality of juvenile sockeye salmon (Oncorhynchus nerka) in Babine Lake, British Columbia. Can. J. Fish. Aquat. Sci. 44: 712-721. Figure I ? Map of the Skeena river and its major tributaries, load show] position in British Columbia. Figure 3. Map of the tour sequential fisheries usea in the management moce i . SECTION IV BYCATCHES AND PURSE-SEINE FISHERIES 53 BYCATCHES IN PURSE-SEINE FISHERIES Martin A. Hall, Inter-American Tropical Tuna Commission, c/o Scripps Institution of Oceanography, 8604 La Jolla Shores Drive, La Jolla, CA 92037 - 1508, USA ABSTRACT A brief discussion of the bycatches in purse-seine fisheries is presented, using as a study case the tuna purse-seine fishery from the eastern Pacific. There are major differences in the utilization of the catch between purse-seine fisheries that produce fish for the reduction industry or for the canning or fresh market. In the former, most of the catch can be used; in the latter, the fishermen retain only some of the mixture of species and sizes that are caught. The bycatch may originate in an ecological association between species, or in a random event. Some examples illustrate these types. The dolphin bycatch in the tuna purse-seine fishery of the eastern Pacific has been reduced by 97% in the past seven years. A brief description of the changes in technology and training that led to these results is presented, to illustrate the gradual and diverse manner in which progress was achieved. There have also recently been attempts to quantify the bycatches of other species and the ecological costs that occur in alternative fishing methods to setting on dolphins. Some of the possible ways to increase purse-seine selectivity prior to capture (better information on school composition, on problem areas or techniques) and after capture (types and sizes of mesh, sorting of fish in the net, handling of fish on deck) are briefly discussed. ? ? ? INTRODUCTION In this review, I will not attempt to summarize all that is known about bycatches in purse-seine fisheries, but only to address some of the com-mon traits of most problems with this type of gear. The readers are directed to Alverson et al. (1994), for additional information. The scientific names of all species mentioned are listed in Appendix 1. As opposed to passive gears that are deployed in a habitat that is deemed favorable to catch fish, purse seines are deployed "on fish." When a set is made, the fishermen almost always know that they are encircling a school of fish, and they have a pretty good idea of the species encircled and of the sizes of fish in the school. The accuracy of this information changes from fishery to fishery and from species to species, and may be affected by oceanographic or meteorological factors. In spite of this, there are bycatches of non-target species and/or of unmar-ketable individuals of the target species. From the point of view of the bycatch, it is necesary to distinguish the purse-seine fisheries that produce fish for canning or fresh consumption from those that produce fish for the reduction industry. Because of the characteristics of the product, fishmeal plants can utilize a wide variety of species, even the catch of non-target species can be utilized and becomes a "catch." Practically all sizes caught can be utilized, so there is no discard of unmarketable fish (Guillory and Hutton, 1982). The fact that almost everything can be utilized doesn't mean that there is no ecological impact from some of those captures. It can be argued that to utilize for making fishmeal, species that could be used instead for direct human consumption is a sub-utilization of a resource. Also, the takes of juveniles or small-sized individuals of species of commercial value that may be captured with the target school, are a form of growth-overfishing. Apparently, the larger species incidentally caught in some reduction fisheries are discarded at sea or while unloading (Guillory and Hutton, 1982), so it is not possible to assess this impact. When the object of the fishery is the canned or 54 fresh-fish market, the fishermen have to he more selective. In some cases, undersized fish of the target species require more labor, and that affects the production costs, to the extent that some canneries cannot afford to process the smaller sizes. Or they may not be acceptable to the consumers. Most non-target species cannot be used in the cans, and their utilization depends on the existence of a market for them. If there exists such a market, and the price per ton is not much lower than the target species, then they can be retained and sold, becoming part of the catch. Unfortunately, in many cases there are no markets for some species, or the price differ-ences are too high to justify the loss of space in the vessel wells, so they are discarded at sea. From the ecological point of view, the bycatch in purse-seine sets comes from two sources: (a) the "associated" bycatch, composed of individ-uals that were swimming (or feeding, or resting, or any other behavioral pattern) in association with the target species, and (b) the "chance" bycatch, composed of individuals that happened to be in the area enclosed by the net or wandered into it during its deployment. Examples of the first type are the sharks and biilfishes that are caught with tunas and dolphins in the eastern Pacific Ocean; the types of association include both temporary and long-lasting ones, and the relationships involved in the association include predators that were feeding on the target species, competitors that were feeding on the same prey items, small-sized conspecific individuals that were part of the same school, members of polyspecific aggrega-tions (Au, 1991), prey that were being consumed by the target species, etc. As most fish schools have some degree of size segregation, it is unusual to find a broad range of sizes in the same school, but fish smaller than the smallest size that is accepted by the market may be within the range present in the school, and that will generate discards from the catch. Another situ-ation leading to the capture of a mixture of sizes is the encirclement of two or more schools that may be associated in a temporary way around a fooid source, as a response to predators or other perceived threats, or to some oceanographic feature. Examples of the second type of bycatch include sea turtles, the proverbial innocent bystanders, caught in sets on tunas associated with dolphins. For small purse seines, the second type may be low, but for large nets (e.g. 1.5 km long and 200 m deep) the volume enclosed is so large that those chance captures may occur frequently. The mortality of purse seine-caught animals is caused by asphyxiation due to crowding in the sack of the net, entanglement in the net, and asphyxiation on the deck of the vessel. Air-breathing animals may also become trapped in some portion of the net beneath the surface of the water and asphyxiate. Occasionally animals which are alive, but entangled in the net, may be carried toward the power block and fall from there to the deck, which is likely to injure or kill them. SOME EXAMPLES OF BYCATCHES IN PURSE-SEINE FISHERIES There has been a problem with dolphin bycatches in the tuna purse-seine fishery of the eastern Pacific Ocean since the late 1950s. For reasons still unknown, yellowfin tuna swim with some dolphin species. The most common way of fishing in that area is to encircle a group of dolphins to capture the tuna school that is associ-ated with it. In the early years of the fishery, the levels of incidental mortality of dolphins were high (average of about 350,000/year during the 60s),which caused declines in most of the dol-phin populations involved. The fishermen soon found ways to reduce the incidental mortalities, and the levels of mortality dropped to 20,000 to 40,000 in the early 80s. More recently, more effort on dolphins, and the incorporation of many skippers and crews that had no experience in this way of fishing caused the mortality to increase again, peaking in the mid 80s. The last few years have seen a decline of about 97 % in mortality, from 133,000 in 1986 to 3,600 in 1993 (Lennert and Hall, In Press). Most of these improvements came from the development of a series of modifications of the purse-seine, and the application of sound techniques to release the dolphins encircled (National Research Council, 1992; Joseph, 1994). The changes include technology and procedures: 1) different mesh sizes in some portions of the net, 55 2) an additional maneuver after encirclement, the "backdown", 3) the use of towing speedboats and a skiff, 4) the use of a dolphin rescue raft, 5) a different tying up of the corkline, 6) the addition of a floodlight on the vessels, 7) the use of a jet engine auxiliary boat, 8) .. new concepts are being tested at this time And also education and training to improve the decision-making of the skippers and the special skills of the crews: 1) training of speedboat and skiff drivers, 2) training of raftperson, 3) training of deck boss and crew in the handling and maintenance of the equipment, 4) training of skipper and crew on the backdown maneuver, 5) training of skippers to identify the risk factors that lead to high dolphin mortality, and the counteractions required. The reasons to include a long list of rather specific information are: I) illustrating the variety of changes that can be tried; II) showing that even though some developments were more influential than others, there was no magic solution, but an accumulation of small and large changes over decades; III) that technology alone did not solve the problem; IV) that the process is still moving forward. From the beginning of the fishery, when annual mortality was, on average, close to 350,000 to the level of 3,600 in 1993, the reduction in bycatch was 100-fold. But it wasn't fast, it wasn't easy, it wasn't cheap. In recent years the dolphin populations have remained stable (Anganuzzi and Buckland, 1994). Another common way to purse-seine for tunas is to use the association of tunas with floating objects of different types. Again, for reasons unknown to scientists, tunas of some species (e.g. yellowfin, skipjack, and bigeye) associate during the night with drifting objects. Besides the tunas, other species of fishes, invertebrates, reptiles, etc., associate with these objects, forming characteristic communities. This way of fishing is common in all oceans of the world (Fonteneau and Hallier, 1992), and different studies (e.g. Habib et al., 1982; Hampton and Bailey, 1993; Scott and Anganuzzi, 1992) show that the communities involved are quite similar in composition. Typically they include mahi-mahi, wahoo, several shark species (silky, whitetip, hammerheads), several ray species (manta, stingray), yellowtail, rainbow runners, several billfishes (black, blue, and striped marlin, swordfish), several small tuna species (frigate and bullet tuna, black skipjack, triggerfishes, sea turtles, etc. When a set on a log is made, many of the species listed above are caught incidentally. Table 1 (see paper on Classification of bycatches ... in this report) shows the ecological costs, in terms of bycatches, of producing 1000 tons of yellowfin tuna in different types of sets (associated with dolphins, with logs, or not associated). It illustrates the dangers of making decisions without complete information, and focusing on a single problem. The reductions in dolphin mortality that can be achieved by switching the mode of fishing, have a counterpart in the increase of the bycatches of many other species. To assess whether the alternatives are "better" from the ecological point of view requires a large amount of information which is not currently available (abundances and conservation status of different species, mortality rates from different sources, recruitment rates, etc.) HOW TO IMPROVE THE SELECTIVITY OF A SEINE The first step toward improving selectivity in purse seines is to increase the amount and quality of the information available to the fishermen before deploying the net. Better information on the species and size composition of the schools to be encircled should lead to better decisions concerning whether to deploy the net, or in the deployment itself. This information may be acquired by visual means (e.g. helicopter overflights) but more likely by acoustic techniques. Better sonars, that are affordable to the fishermen, should result in significant improvements. One way to contribute to this goal is to identify areas that are consistently problematic and to 56 avoid them. Areas with large numbers of juveniles of the target species, or of some other species could be closed to fishing, or could be avoided voluntarily. Another way is to identify modes of fishing that have higher incidences of bycatches than others, and reduce their frequency. HOW TO IMPROVE RELEASE FROM A SEINE After encirclement, the characteristics of the net play a major role in reducing bycatches. Several experiments showing the impacts of different mesh sizes and of different types of mesh (square, hexagonal, diamond-shaped) on the escapement of fish which are encircled by seine have been conducted. A recent review can be found in Ben Yami (1994). The regulation of mesh sizes of trawls and other nets has been used for many years to limit the captures to some desirable sizes. However, the fact that some fish escape the net doesn't necessarily ensure that they will survive. Some species, such as mackerel, have little resistance to the physical stresses involved in the capture process, and die soon after release (Pawson and Lockwood, 1980), while others are much more hardy. These differences highlight the need to back up the management decisions with experiments to determine if the effects sought can actually be achieved. Perhaps different species, or different size-groups could be manipulated inside the net, to allow their release when it is desired. This type of solution would require a solid knowledge of the behavior of the different species in the net, especially of their horizontal and vertical stratification, and their responses to different stimuli that could be used to herd them or separate them (e.g. air curtains (Smith, 1963, Kim and Choo, 1993), sounds, scents, lights, etc) and also the development of modifications in the net such as zippers (Coe et al., 1984) or the use of rigid grids inside the net to facilitate the escapement of the smaller fish (Beltestad and Misund, 1993). The development of some system that would allow the tranfer of the catch to some kind of floating cage, through a chute where the fishers could sort the catch, would be a major step towards solving many of the bycatch problems in different fisheries. If this transfer could be performed before crowding the fish in the net, those fish released should have high survival rates. In the case of small cetacean bycatches, some of the techniques and equipment developped in the eastern Pacific fishery to release them from the net could be used in other purse-seine fisheries, some of which have, or are believed to have, incidental takes of dolphins (Northridge, 1984,1991). The possibility of changing the methods of handling of the unwanted fish after they have been brought on board cannot be discounted. This may work only in the case of the most resistant species, such as sharks, because they must survive not only crowding in the net, but also the crushing in the brailing system and lack of water on their gills on the deck of the vessel. REFERENCES Alverson, D.L., Freeberg, M.H., Pope, J.G. and Murawski, S.A. 1994. A global assessment of fisheries bycatch and discards. FAO, Fisheries Technical Paper. No. 339. Rome, FAO, 233 p. Anganuzzi, A.A., and S. Buckland. 1994. Relative abundance of dolphin associated with tuna in the eastern Pacific Ocean: Analysis of 1992 data. Inter. Whaling Comm., Rep., 44:361-366. Au, David. 1991. Polyspecific nature of tuna schools: Shark, dolphin, and seabird associates. Fish. Bull., U.S. 89:343-354. Beltestad, A.K. and Misund, O. A. 1993. Sorting of mackerel by grids in purse seines and trawls. (In Norwegian with English summary). Fisken-Havet, Nr. 8, 21 pp. Ben-Yami, M. 1994. Purse seining manual. Fishing News Books, Oxford. 406 pp. Fonteneau, A. and Hallier, J.-P. 1992. Lapeche au thon sous objets flottants. La Recherche, vol. 23: 1316-1317. Guillory, V. and Hutton, G. 1982. A survey of bycatch in the Louisiana Gulf Menhaden 57 fishery. Proc. 36th. Annu.Conf. Southeast. Assoc. Fish-Wildl. Agencies (SEAFWA). Jacksonville, Florida, Oct.31-Nov.3, 1982. p.213-223. Habib, G, Clement, I.T., Bailey, K.N., Carey, C.L., Swanson, P.M. and Voss, G.J. 1982. Incidental fish species taken in the purse-seine skipjack fishery, 1975-1981. Occasional Publication: Data series No. 5, Fisheries Research Division, New Zealand Ministry of Agriculture and Fisheries. 49 pp. Joseph, J. 1994. The tuna-dolphin controversy in the eastern Pacific Ocean: biological, economic and political impacts. Ocean Development and International Law, 25(1): 1-30. Kim, J.O. and Choo, H.D. 1993. A study on the fish behavior control by air-bubble curtains. Bull.Nat. Fish. Res. Dev. Agency, 47:241-249. In Korean with English summary. Kristjonsson, H. (ed.) 1971. Modern Fishing Gear of the World 3. Fishing News Books, Oxford. 537 pp. Lennert, C. and Hall, M.A. In Press. Estimates of incidental mortality of dolphins in the eastern Pacific Ocean tuna fishery in 1993. Rep. int. Whal. Commn. 46. Northridge, S.P. 1984. World review of interactions between marine mammals and fisheries. F.A.O. Fish.Tech. Paper Nr.251. Northridge, S.P. 1991. An updated world review of interactions between marine mammals and fisheries. F.A.O. Fish.Tech. Paper Nr.251, Suppl. 1. Pawson, M.G. and Lockwood, S.J. 1980. Mortality of mackerel following physical stress, and its probable cause. Rapp. P.-v. Reun. Cons. int. Explor. Mer, 177:439-443. Scott, M.D. and Anganuzzi, A. 1992. Report of the Workshop. Workshop on the ecology and fisheries for tunas associated with floating objects and on assessment issues arising from the association of tunas with floating objects. February 11-14, 1992, La Jolla, California. Inter-American Tropical Tuna Commission. Smith, K.A. 1963. The use of air-bubble curtains as an aid to fishing. Modern fishing gear of the world, Vol.2:540-544. Lockwood, S.J., Pawson, M.G. and Eaton, D.R. 1983. The effects of crowding on mackerel (Scomber scombrus L.)- Physical condition and mortality. Fish. Res. 2: 129-147. Misund, O. A. and Skeide, R. 1992. Grid-sorting of penned saithe. ICES C.M. 1992/B:11, 5pp. Misund, O.A. and Beltestad, A.K. 1994 (to be presented at the ICES meeting in September, 1994) Size-selection of mackerel and saithe in purse seine. ICES C.M. 1994/B:28, Ref. G.H. 12 pp. National Research Council. 1992. Dolphins and the tuna industry. National Academy Press. 176 pp. 58 APPENDIX 1 Tunas yellowfin tuna skipjack tuna bigeye tuna black skipjack frigate tuna bullet tuna Thunnus albacares Katsuwonus pelamis Thunnus obesus Euthynnus lineatus Auxis thazard Auxis rochei Dolphins spotted dolphin spinner dolphin common dolphin Billfishes black marlin blue marlin striped marlin swordfish sailfish Sharks and rays silky shark blacktip shark whitetip shark Stenella attenuata Stenella longirostris Delphinus delphis Makaira indica Makaira mazara Tetrapturus audax Xiphias gladius Istiophorus platypterus Carcharhinus Jalciformis Carcharhinus limbatus Carcharhinus longimanus hammerhead shark Sphyrna spp. manta ray Mcmtaspp.,Mobulaspp. sting ray Jam. Dasyatidae Other large pelagic fish species mahi-mahi wahoo yellowtail rainbow runners triggerfishes Coryphaena spp. Acanthocybium solandri Seriola spp. Elagatis bipinulatus Jam. Balistidae Sea turtles olive ridley leatherback loggerhead hawksbill Lepidochelys olivacea (the vast majority) Dermochelys coriacea Caretta caretta Eretmochelys imbricata 59 BY-CATCH IN B.C. PURSE SEINE FISHERIES: RECENT EXPERIENCES IN SOUTH COAST CHUM SALMON FISHERIES Paul Ryall, Department of Fisheries and Oceans, 3225 Stephenson Point Rd., Nanaimo, B.C. V9T 1K3, Canada ABSTRACT Southern B.C. chum salmon fisheries take place in the fall; with the most seaward fisheries taking place in Johnstone and Queen Charlotte Straits. This fishery operates under a framework known as "Clockwork". The name is derived from the stepped harvest rates that occur with changing run size. Basically, the rules are for chum salmon run sizes between 0 and 3.0 mil-lion the harvest rate is 10%, 3.0 to 3.9 million 20%, 3.9 to 5.2 million 30% and over 5.2 million 40%. The objectives of the "Clockwork" plan are: Achieve the maximum potential of the resource and long term benefits to the fishing industry. 2. To rebuild wild chum salmon and sus-tain a spawning stock of wild fish at 2.5 million for the study area. 3. Reach this escapement goal within three cycles (12-15 years). Program was initi-ated in 1983. 4. Learn as much as possible about the productivity of the stocks. 5 Allow limited fishing at low stock sizes. In the last number of years the possibility of adding a sixth objective, minimize by-catch of chinook, coho and steelhead has been raised. In the last three years (1991-93) the average catches of chinook, coho and chum salmon in this fish-ery were 1,700, 17,700 and 909,200 respective-ly. The majority of this incidental catch occurs in late September. It has been these late Septem-ber fisheries that has been the focus point for other resource users. While recognizing the concerns over incidental catch Canada Dept. of Fisheries and Oceans has also found this fishery to be very important in providing accurate stock assessment information. A number of meetings were held with resource user representatives attempting to find a resolution that would meet a number of objectives. Namely, allow for a late September fishery for stock assessment purposes and reduce the by-catch of chinook, coho and steelhead. The options proposed to the interested parties ranged from maintain the existing com-mercial fishery with voluntary release of chinook, coho and steelhead to not conducting the fishery. The action put into place for 1994 was to hold the fishery at a later date, when abundance of the by-catch species had declined, and with mandatory release of chinook, coho and steelhead by purse vessels and voluntary release by gill net vessels. ? ? ? 60 REDUCING BY-CATCH THROUGH GEAR MODIFICATIONS: THE EXPERIENCE OF THE TUNA-DOLPHIN FISHERY Captain Harold Medina, 3128 Villa Caliente del Sol, Jamul, CA 91935, USA. ? ? ? By 1963 most of the tuna fleet fishing for yellowfin and skipjack tuna in the eastern Pacific from ports in southern California had switched from use of the pole and line method to the purse seine. Although all the boats were famil-iar with the fishing grounds, those who had changed method recently were unfamiliar with the techniques associated with the new gear. Yellowfin tuna in the eastern Pacific are com-monly associated with schools of dolphins and the fishermen had learned to find and catch tuna shoals by setting the net around a school of dolphins with a consequent high mortality of the latter. Operational techniques for releasing the dolphins unharmed from the net were developed and the gear itself was gradually modified in the light of experience to further reduce dolphin mortality. The operational technique that was developed is known as "back down" and relies on the dol-phins remaining near the surface and separated from the tuna shoal once surrounded by die net. When about two thirds of the net has been hauled back on board, the ship is put in reverse, causing the net to elongate into an elliptical shape towards the bow of the ship and the corkline (a row of floats which support the net at the surface) to be dragged below the surface, thereby creating an area through which the dolphin can escape. One of the earlier modifications to the fishing gear was to reduce the mesh size from 4.5 inches (112mm) to 2 inches (50mm) at the end of the net where the escape was intended; this resulted in fewer dolphins tangling their snouts in the netting and drowning. It also acted to increase the drag on that area of the net, forcing it underwater and creating a slide for the por-poises to escape over. Nowadays federal regula-tions require a mesh panel of 1.25 inches (30mm) to be used in this part of the net. Another improvements were: (1) the use of a raft with a crewman inside the net, releasing dol-phins entangled and helping with the release procedures, (2) the use of the speedboats with towing briddles to keep the net open, (3) the use of floddlights to help the rescue in sets in dark-ness, and (4) the use of a double corkline, that allows the dolphins to leave the net simply by pushing on any of the floats. A further modification that is currently being tested is to sew a canvas panel (approximately 3m deep by 30m long) below the corkline in the escape area to further increase the drag effect and to ensure that this area of the net retains sinks faster and deeper, and retains its shape without collapsing, thereby allowing even the smallest dolphins to avoid entanglement and to escape over the top of the net. Water welling over the top of the corkline assists the dolphins out of the net. Speedboats and rubber rafts are also used to assist in herding the dolphins to the right area, and any that do get entangled are often released by crew members with snorkel gear. There is some evidence of learned behavior in dolphins that have been captured before; they appear to know when and where an escape gap will be formed and will wait until the right moment before attempting to escape. The use of all these methods allow the escape of some 99.5% of encircled dolphins and the only time that any mortality is encountered is when an operational problem, such as the net rolling up, traps some animals under water. Currently about 84% of the sets made "on dolphins" do not cause any mortality; this number was about 40% in 1986. Finally, perhaps the most important factor in achieving the results obtained has been the awareness and motivation of skippers and crews. (Tape transcribed by Martin Esseen, Fisheries Centre, UBC.) SECTION V TOWARDS SOLVING THE BYCATCH PROBLEM 61 BYCATCH STRATEGIES: SUCCESS STORIES, PROMISING APPROACHES, AND ROLE OF THE THIRD SECTOR Brad Warren, National Fisheries Conservation Center, c/o National Fisherman, 4055 21st Ave. W., Seattle WA 98112, USA. ABSTRACT Among common strategies for addressing bycatch problems, the sharpest debate has focused on access-based reforms: quota and reward regimes that use permission to go fishing as either carrot or stick to reduce bycatch or associated mortalities. Such reforms amount to writing a new constitution for fisheries. They redefine the "citizenry" of a fishery and pro-foundly alter relations between the individual and the state. But such deep change isn't easy. Political and institutional obstacles, which impede most bycatch solutions, may render access-based reforms impossible in many fish-eries. This article suggests that non-government science and advocacy organizations are changing what is possible. Hard-hitting environmental groups have (largely unwittingly) created the preconditions for at least one fishery to make access-based reforms and other difficult solutions politically feasible. More moderate science and conserva-tion groups have begun to facilitate bycatch experiments and measures that the fishing indus-try and government, if left to their own devices, could not undertake. Such interventions, how-ever, must be delicately managed to support real problem-solving. Otherwise they risk spinning into simplistic campaigns that serve neither the resource nor those who harvest it. ? ? ? BACKGROUND ON THE NFCC With the help of National Fisherman magazine, in early 1994 the National Fisheries Conserva-tion Center (NFCC) was created to promote cooperative problem-solving in the areas of fisheries bycatch and conservation. Operating] as a project of the Fisheries Management Founda-tion, we are preparing a handbook and organiz-ing a forum at FISH EXPO Seattle on "Win-Win Bycatch Solutions." The handbook addresses strategies for collaborative problem-solving in bycatch and provides a directory of resources and expertise in the area.1 We've addressed not only the fisheries commun-ity (fishermen, scientists, managers), but also to the newcomers in this arena, conservation com-munity and grantmaking foundations: They represent the non-profit "third sector" of America's economy, which plays a major role in social and environmental problem-solving in many areas of modern life. Most of them are still just learning the ropes in fisheries. One of our aims is to help them find ways to contribute genuinely to solutions, linking their skills and resources to those already engaged in fisheries problems. As part of our research this year we talked to people in fisheries all around the United States to find out what kinds of bycatch approaches have proved successful or promising. The results suggest some important characteristics of the political institutions that shape what kind of solutions are attainable. "MY LAWYER IS BIGGER THAN YOURS" The most powerful, and controversial, methods for controlling bycatch are access-based: they put caps on what individual vessels can take. This amounts to changing the rules for access: fish clean or quit. In principle, everybody loves these systems because they provide individual accountability. Under most of the individual quota schemes and "harvest priority" ideas that are being debated in Alaska, for instance, a fisherman could not externalize the cost of sloppy fishing as he can under an open-access regime. But in practice, the United States is a tough place to tell somebody he or she can't go fishing while the rest of the fleet is still grinding away on the grounds. Try instituting one of these regimes and you quickly run into a big obstacle: the "my-lawyer-is-bigger-than-yours" syndrome. "Win-Win Bycatch Solutions", pubished December 1994, is available from NFCC. This is a built-in flaw in our democracy. In a system designed to give everbody a fair crack, the founding fathers made sure anybody can haul you into court if they think you unfairly cut off their access to the public bounty. And in this country we are quick to reach for our lawyers. This has a profound effect on what can be accomplished in the way of fisheries policy. In fact, some people have speculated that the United States may never be able to follow British Columbia's lead in instituting an effecitive program of individual fishing quotas for longline fisheries, because the lawsuits will drown out the benefits. Looking at fisheries in light of these issues has led me to a hypothesis. I'd like to ask you to help evaluate it. It seems that there may be two preconditions, one or both of which are necess-ary to make access-based bycatch controls politi-cally feasible: ? First, you need a fishery where nobody has recourse to the U.S. courts to challenge the new system. This means the fishery is either outside U.S. jurisdiction, or the people whose access is being tinkered with are foreigners, operating more or less as "guests" in U.S. waters. ? Second, the fishery has to face a mortal threat to its future. If you look at the success of the individual mortality quota on dolphins in the Eastern Tropical Pacific, you see a fishery that had become an international pariah. Some of the toughest environmental advocates in the business had made their careers villifying the purse-seine tuna fishery in that region, and they had suc-ceeded in virtually wiping out the U.S. fleet that once dominated the fishery. They had already helped drive the Asian high-seas drifitnetters off the Pacific by U.N. decree. There was no reason to hope for any leniency toward Latin American purse seiners. What's more, they had already persuaded the U.S. government to embargo the Latin Americans who took over had the ETP fishery. I would say they had good reason to be anxious about their future. It wasn't a question about which boat would get the fish; it was a question of whether any of them would if they couldn't prove conclusively that they could fish tuna without killing significiant numbers of dolphins. The mortality quota in the Eastern Tropical Pacific tuna fleet is a successful access-based control. The fleet catches tuna by wrapping seine nets around the easily spotted schools of dolphins 62 that apparently attract the most desirable tuna. By 1992 a long process or refining gear and fishing practices had gradually reduced dolphin mortalities from somewhere in the hundreds of thousands to about 15,000 animals per year. Then in 1993, the quota took effect. It spurred a dramatic drop in mortalities. That year the fleet cut dolphin deaths to 3,605 animals ? a better-than-fourfold drop. The fleet actually outperformed its goals and finished the year far ahead of the newly lowered cap on mortalities. And little wonder Skippers who failed to avoid killing dolphins saw their jobs jeopardized. Owners saw their investments imperiled. They got very serious about using the techniques for reducing mortalities. Two points are worth noting about the context within which all this happened. 1. Reliability of data. The data underlying the quota was extraordinarily trustworthy. By 1993, dolphin mortalities in the Eastern Tropical Pacific tuna fishery were few enough, and well-enough monitored, to be outright counted, not just estimated. On-board observers recorded and described every dead dolphin in detail. So if anybody wanted to challenge the decision to terminate a boat's season for killing too many dolphins, they would have a rough job. I haven't included this in my list of hypothetical precondi-tions, but if you want to apply access-based controls, especially in the United States, this kind of hard data may be essential. In the North Pacific, the statistical uncertainty of bycatch estimates has scuttled a number of promising bycatch initiatives, because policy-makers reckoned the lawyers would make hay out of that uncertainty. Just imagine the courtroom scene:. Plaintiffs Attorney: Mr. Codwatcher, are you telling me you don't actually know how many juvenile pollock my client caught, but you still shut him down for catching too many? (To Judge) Your honor, i rest my case. 2. Jurisdiction. The fishery occured outside of U.S. jurisdiction in Latin American or interna-tional waters. The international authority that established the quota system was not a U.S. agency. And the Latin Americans who inherited this fishery from the vanquished U.S. fishermen were not subject to American law. This meant that they could work out a solution to the dol-phin-mortality problem in their own way. 63 TO KILL OR TO CURE? This leads to a delicate political matter. In the U.S., the movement that led to our "dolphin-safe" policies ? a virtual ban on encirclement of dolphins ? was driven by outrage and a desire for harsh justice. The San Diego tuna fleet was widely seen as a group of evil-doers, slaugh-terers of dolphins. The fishermen had actually sought government help to reduce dolphin mortalities in the late 1960s, but the resulting disclosure of shockingly high mortalities did not foster a great public impulse to help them solve the problem and stay in business. The dolphin kill became a galvaniz-ing theme in the early years of the environmental movement. Like most of the political leaders of the age, the new environmental leaders cut their teeth in a time when political leadership was based mainly on military models. The way to promote justice was to defeat wrong-doers: Destroy Hitler, beat the Communists, overthrow the dictator.Winning was about vanquishing enemies. That approach has since mellowed in many areas of environmental discourse, but with regard to fisheries conservation problems it remains a powerful theme in our politics and our policy-making. Especially where bycatch and waste are involved, and even more so where marine mam-mals are being killed, the impulse for vengeance runs hot. A strong element within the environ-mental community, and in government, still gathers great energy from a "crusade" approach to fisheries problems. The prevalence of this view in the United States may have made it impossible to develop any viable solution for the U.S. tuna fleet. Neither the schoolchildren who wrote to Congress, nor the environmental groups who led the campaign for "dolphin-safe" policies, were very interested in allowing the U.S. tuna fleet in the ETP to stay in business while reducing dolphin mortal-ities. To cure the disease we killed the patient. But inadvertantly, the enormous pressure gener-ated by the dolphin-protection movement did make it a lot more feasible for the Latin Ameri-cans who took over the fishery to bite some hard bullets on access-based controls. Those controls, not the "dolphin-safe" policy, have essentially solved the dolphin problem in the region. But it's an important question whether we in the United States have the political fortitude to help fleets solve their bycatch problems. Canada so far has done a little better. There are reasons for hope in New England as well. AN ALTERNATIVE APPROACH One Newfoundland gillnetter had better luck than the San Diego purse seiners when he asked for help. It was 1978 and he had spent three months ? really, this is not a joke ? trying to disen-tangle a whale that was snarled up in his web-bing. The beast was looking hungry, and the fisherman was too, when Jon Lien, a professor of animal behavior at Memorial University of Newfoundland's Whale Research Group, arrived with a group of students to disentangle the whale. To put this in perspective, this is not a lucrative fishery where vessel owners can afford to support expensive research to solve their problems. Average income in the gillnet fleet in that region has been about $10,000 a year. Since then, Lien's group at Memorial University has set up a program that regularly helps fisher-men separate their gear from whales. Lien estimates that each "whale rescue" saves an average of $1,300 for fishermen ? in lost gear and fishing time. Each rescue also trims whale mortalities from about 50% to 10%. Lien has also played an important role in efforts by New England sink gillnetters to reduce entanglement of harbor porpoises. The numbers are disputed, but federal estimates peg the porpoise kill at about 2,900 animals in 1990; they reduced the kill to about 900 animals in 1992, and maybe slightly more than that in 1993. Whether the harbor porpoise stocks can sustain this pressure is unclear. Neither their abundance nor their fecundity is well under-stood. The National Marine Fisheries Service (NMFS has been petitioned to list them as a threatened species. Conservation groups in 1993 began focusing national attention upon this fishery. Fishermen reckoned they had to solve the problem or be forced out of business. They initially sought Lien's help in hopes of avoiding a swath of closures that the fisheries service was preparing to impose to keep them off the water during times of high porpoise entanglement. Lien had invented a "pinger" to warn whales away from cod traps, and a series of shoestring experiments in the Gulf of Maine convinced the gillnetters that it could keep harbor porpoises out of their gear. They also liked the fact that the devices are cheap - about $20 ? and relatively easy to build. But NMFS wasn't sold on the pingers. Without the agency's approval, the devices would not help fishermen even if they worked brilliantly; NMFS would still rely on other methods to control their porpoise lull. The trouble was, noisemakers in general had a spotty record in scaring away mammals. Some early experiments seemed to show they acted like a dinner bell when salmon fishermen in the Pacific Northwest sought to scare away seals. The idea of conducting a large-scale test of to determine the efficacy of the pingers made sense in principle, but how to do it was a matter of s h i p dispute between NMFS and the fishermen. Their disagreements were many and intense, and several observers have suggested that they could not have come to terms on a research protocol without intervention by some interested third parties. The "intervenors" turned out to be the National Fish and Wildlife Foundation, the New England Aquarium, and the Manomet Observatory. They had the scientific credibility that it took to satisfy NMFS and willingness to listen that they needed to work with fishermen. An experiment began in autumn, 1994, deploy-ing pingers in a standardized array on 15 cod gillnetters in New England. Funded partly by the Fish and Wildlife Foundation (with money from the federal disaster assistance program for New England groundfish fleets), the study is expected to provide a basis for determining whether pingers offer a viable policy alternative to more costly closures to protect the porpoises. THE NEED TO BUILD PROBLEM-SOLVING CAPACITY 64 The entry of non-government organizations (NGOs) into the fisheries management arena is refraining this picture in two ways. First, those groups that crusade against "destructive" fleets have (perhaps unwittingly) taken on the role of creating the mortal threat required to induce access reforms - or at least to spur effective bycatch-reduction programs. Second, other groups have embraced a more collaborative role: acting to support innovations in fishing technique and management that might enable fishermen to "clean up" their fisheries enough to survive the heat. There is a valid and useful role for environ-mental "pressure" groups in fisheries, but it seems to me that the problem-solving end of the spectrum is where we most need to build capac-ity. Otherwise, the pressure will merely van-quish fisheries, rather than solving their prob-lems, and many people who are hurt by that Draconian approach will continue to drift into reactive, cynical postures: joining the so-called "Wise Use" movement, digging in their heels against the whole effort to conserve resources, and so on. Then we'll have a discourse domi-nated by the extremes, hard-line preservation vs. rampant exploitation, and we will risk losing sight of the real aim: sustainability. It's tough to imagine a stronger way to promote bycatch reduction than to make fishing rights contingent upon bycatch performance. But the political prospects for such access-based reforms look poor for now, at least in the United States. These regimes raise difficult questions about the just distribution of public resources. They require uprooting established patterns of com-merce, enriching some fishermen and processors at the expense of others. Those who lose ?or think they might ? are prone to hire lawyers. 65 A CLASSIFICATION OF BYCATCH PROBLEMS AND SOME APPROACHES TO THEIR SOLUTIONS Martin A. Hall, Inter-American Tropical Tuna Commission, c/o Scripps Institution of Oceanography, 8604 La Jolla Shores Drive, La Jolla, CA 92037 - 1508, USA ABSTRACT An attempt is made to seek some common traits and some basic differences among bycatch problems in fisheries. Even though the existence, level and nature of the bycatch problem vary widely, we can identify some basic types of bycatch using: (a) spatial and temporal patterns in its occurrence, (b) degree of control by the fishermen, (c) rarity, (d) predictability, and (e) origin of the bycatch. A classification of bycatch problems helps to pinpoint the strategies that can be used to mitigate them. The bycatch problem, when it exits, can be attacked in two fronts: reducing effort or reducing the bycatch per unit of effort. Different ways to achieve these goals are discussed, including technological changes, regulations, and training of fishers. From the technological point of view, we can increase selectivity prior to capture by improving the release of unwanted individuals after capture, either in the net or on deck. Another technique to reduce bycatches is the opening of markets for new species, which converts bycatches to catches. Up to now, none of the sectors involved in the global bycatch problem has been very successful in implementing coherent, continued and well-oriented efforts towards achieving some long-term goals that need to be defined. There are challenges for scientists, for managers, for fishermen and for environmentalists that need to be faced in the near future. The major challenge, however, is to bring all the sectors together, even those that appear to be in conflict now, to work in concert towards these long-term goals. ? ? ? INTRODUCTION "Bycatches" are defined by Alverson et al. (1994) as animals other than the target species plus individuals of the target species which are unmarketable because they are too small or for some other reason, Bycatch problems have probably existed since the beginning of world fisheries. Harpoons, arrows, spears, can be aimed at an individual of known species and size; handlines with hooks can be used in such a way that they are quite selective, but almost invariably there will be catches of unwanted species or individuals; however, some of these can be returned to the water alive. But other early forms of fishing, such as the use of poison-ous substances (e.g. plant toxins from Euphorbia spp., Verbascum spp., Derris spp. (Merino, 1991), traps, longlines, or gillnets, were not very selective, and in many cases, the bycatches could not be released alive. However, increases in human population, indus-trialization of many fisheries, full utilization or overexploitation of most marine living resources, and a growing awareness of the potential eco-logical impacts of the problem have brought the issue to the forefront of fisheries science. A recent review (Alverson et al., 1994) gives an idea of the magnitude of the problem for differ-ent types of gear and regions. That study also shows that reliable data are scarce or non-exist-ent for most fisheries, and that problems are apparent for those that are closely monitored. Increased data collection is needed to identify the problems, diagnose the causes, and search for solutions. But not all bycatch problems are equal, and at this stage, we could benefit by some generalizations with regard to the different types of problems. To illustrate many of the points, I will use the information on bycatches of different species in the purse-seine fishery for tunas in the eastern Pacific Ocean. This is a large data set, containing more than 5,500 records of bycatches in purse-seine sets. TYPES OF BYCATCH PROBLEMS I) Concentrated versus diffuse Some bycatches occur in well-defined spatial and/or temporal strata. Examples of this include 66 Figure 1: Bycatch rates of sea turtles (per 100 sets) for ail types of sets. Based on 1992-1993 data. An intermediate degree of concentration is shown in the case of the wahoo (Acanthocybium solandri, Fig.2) and the mahi-mahi (Coryphaena spp.. Fig.3) in the tuna purse-seine fishery. Bycatches of these species are quite high in a much larger area of the fishery than in the case of the sea turtles. However, there is a high degree of spatial heterogeneity, and there are areas where the bycatches are very low. A more diffuse case is exemplified by some species of billfishes (Fig. 4) such as the black and striped marlins in purse-seine sets made on dolphins. Here the bycatches are more uniform over the whole range of the fishery; there are no "hot spots." These differences are important because they determine, or at least constrain, the possible strategies to mitigate the problems. If these distributions are stable over time and/or space, they introduce an element of predictability in our management scheme. We can produce plots such Figure 3: Bycatch rales of mahi-mahi, Corvphacna spp.. (per 100 sets) for ail types of sets. Eased on 1992-1993 data. as those shown in Fig. 5. giving us a clear idea of the trade-offs involved in any attempt to reduce the bycatches. The plot of loss in catch versus reduction in bycatch may show: 1) steep slopes and convex shapes (Fig. 5a) when the bycatches are highly concentrated, indicating that management options (in this case areal or tem-poral closures) are available, their potential effectiveness and their costs or, 2) more linear functions (Fig. 5b) when the bycatch rate is quite constant, indicating that the reduction of the bycatch would be made at the expense of catches most migratory species, species with small ranges, etc. Sea turtles that aggregate near a nesting beach in large numbers and for a short period of time show an extreme degree of con-centration; sometimes they also aggregate in oceanic feeding grounds. Bycatches of sea turtles in these areas are much greater than the average over the whole fishing ground (Fig. 1). Figure 2: Bycatch rates of wahoo, Acanthocybium solandri, (per 100 sets) for all types of sets. Based on 1992-1993 data. BYCATCH M a l i i n t a l i i b y c a t c h p e r 100 s e t s (All s e l5 ) 67 Figure 4: Bycatch rates of bitlfishes (per 100 sets) for sets. Based on 1992-1993 data. Bycatch Reduction Curves Tuna calch I o n % 0 10 20 30 40 SO 60 70 M 90 100 Striped nurlta all types of of the target species, unless technological sol-utions are found. For these linear functions, we can compare the bycatch/total catch ratios, and decide which ways of fishing or which gears are better, or which ratios are "acceptable" based on whichever criteria are chosen to make this decision. The problem with this type of approach is that it is based on the bycatch of a single species; the function we really need to compute is the "aggregated ecological cost" of the fishing operations, including the bycatches of all spe-cies, mechanical damage to the habitat, pollu-tion, etc. Reductions of this cost should be plotted against the losses in catch. II) Controllable versus un-controllable In the case of the incidental mortality of dolphin in the tuna purse-seine fishery, in a particular location at a particular time the performance of the fishermen plays a major role in determining the bycatch level; this bycatch is more control-lable than others. But there are many different levels of control; the bycatch level in more passive gear, such as gillnets or longlines can be controlled, at least in part, by the location of deployment, form of deployment, etc. Trawl hauls can be aborted under certain circum-stances, thus reducing the bycatch. But there is a continuum of control levels, and the degree of control of the bycatch in a fishery will indicate whether training programs for fishermen can be Figure 5: Bycatch reduction curves. Losses in catch of tunas (on the x-axis) corresponding to different levels of bycatch reduction for a given bycatch species (on the y-axis). Examples for a species with a highly aggregated distribution of its bycatches, the wahoo, ' in curve (a) and a less aggregated case, the striped marlin in curve (b). The curves are generated by successive elimination of time-area squares (time in monthly periods and areas of 5 degrees x 5 degrees), with decreasing bycatch/catch ratios. Note that horizontal and vertical scales are not equal. effective. The training can be directed toward avoiding the problem or, if that is not possible, toward dealing with it. For instance, a procedure called "resuscitation" can be used with sea turtles that have been entangled in fishing gear, and many respond positively to it. But for many fisheries it will be difficult to ascertain which is the level of control by the fishermen, and we should not assume quickly that the level of control of a fishery is low. simply assuming that random events are the causes of the problems. Ill) Rare versus common Some species are seldom involved as bycatch in a fishery. This can happen for two basic reasons: a) the species is rare, or b) because of its behavior, ecology, morphology, etc., it is not vulnerable to the gear, and some exceptional circumstance generated the problem. The second case is not very significant, but the first one may Tuna catch b a a % 0 10 20 30 40 SO 60 70 00 90 100 68 be. The ecological significance of rare species is difficult to assess, and frequently our knowledge of them is so scarce that it is impossible to estimate the impact of the takes, or to diagnose the factors that cause it in order to mitigate them. In fact, species which are believed to be rare may not really be so rare, but may appear to be rare because they are nearly invulnerable to capture in all types of fishing gear used in the areas where they occur. IV) Predictable versus unpredictable We have already mentioned the issue of predicta-bility when discussing how to deal with some concentrated bycatches. Unpredictability can originate in different ways: a) rare species bycatches will tend to be unpredictable because our databases will be insufficient to describe their distribution in a quantitative way; or b) species with highly-variable recruitment may show up in the bycatches at very different levels in different years; or c) the behavior or ecology of a species may be modified by some external factors (e.g. "El Nino," flood, etc.). V) Associated versus "random" The species that constitute the bycatch of a fishery may be caught because they are associ-ated in some way to the target species. Or it may be a "chance" bycatch, composed of individuals that happened to be in the area enclosed by the net or wandered into it during its deployment. Examples of the first type are the sharks and billfishes that are caught with tunas and dolphins in the eastern Pacific Ocean; the types of associ-ation include both temporary and long-lasting ones, and the relationships involved in the association include predators and prey of the target species, competitors that were feeding on the same prey items, small-sized conspecific individuals that were part of the same school, members of polyspeeific aggregations (Au, 1991), etc. As most fish schools have some degree of size segregation, it is unusual to find a broad range of sizes in the same school, but fish smaller that the smallest size that is accepted by the market may be within the range present in the school, and that will generate discards from the catch. Another situation leading to the cap-ture of a mixture of sizes is the encirclement of two or more schools that may be associated in a temporary way around a food source, as a response to predators or other perceived threats, or to some oceanographic feature. Examples of the second type of bycatch in tuna purse-seine fisheries include sea turtles, the proverbial innocent bystanders, or, in some cases, cetaceans and seabirds in such gears as trawls or gillnets. BASIC STRATEGIES TO MITIGATE BYCATCH PROBLEMS The basic formula to estimate the total bycatch of a given species, caused by a given gear is a good starting point to visualize the strategies that can be used to reduce it (Hall, In Press): Total bycatch = Total effort x Bycatch per unit of effort To reduce the total bycatch there are two options: 1) trying to reduce the total effort, or 2) trying to reduce the bycatch per unit of effort (BPUE). Of course, both options can be pursued simultaneously. Reducing total effort Banning effort or limiting the level of effort: this can be done directly, as a regulation promul-gated by one or more governments (e.g. the recent ban on the use of drift gillnets on the high seas) or, indirectly, through the use of economic forces (demand, prices, etc.). Embargoes, con-sumer campaigns, boycotts, and tariffs, can be applied toward achieving this goal (e.g. recent US embargoes on tunas and shrimp related to bycatch problems, and the "dolphin-safe" cam-paign (Joseph, 1994)). These options are open to governments, but also to industries, advocate groups, etc. As a. result of these actions, demand for a product may drop, markets may close, prices may decrease, etc., and fishing effort should be affected by those forces. The effec-tiveness of these measures will depend on the viability of the enforcement and control mechan-isms, public response, etc. If they are effective, the effort will be stopped or reduced, or in some cases it may be re-directed toward another target species or toward the same species, but with different gears. Unless a feasible alternative is 69 developed, it may lead to the loss or limitation of the use of the resource. Only a prosperous society can afford to give up use of a resource; it seems unlikely that third-world countries with social and economic priorities different from those of the developed world could be in a position to make this kind of sacrifice. Another factor to take into account is which are the alternatives available. Other ways of fishing may be more detrimental to the ecosystem that the current one, for example, attempting to reduce the bycatch of dolphins by redirecting effort toward tunas not associated with dolphins would result in lesser catches of yellowfin tuna (Punsly et al, 1994) and high bycatches of many other species (Joseph, 1994, Hall, Unpub.ms.). Setting limits on the bycatch levels allowed: If the fishermen cannot find ways to reduce the BPUE, they will be forced to cut effort to stay within the limits. A more desirable solution is the development of alternative ways of fishing that will allow the fishermen the continued use of the resource, while at the same time reducing the negative impacts of the fishery. A thorough assessment of the impacts of the proposed alternatives must be carried out before promoting them. Reducing the bycatch per unit of effort Depending on the characteristics of the fishery, different options will be available to achieve this goal. Technological change: In many cases, bycatch problems can be eliminated, or at least reduced, by technological improvements in the fishing gear, mode of operation, materials, etc. The use of turtle-excluder-devices (TEDs) in the shrimp trawls, the backdown maneuver and the Medina Panel while purse-seining for tunas associated with dolphins, pingers in gillnets, square mesh in some areas of the net, grids, etc., are examples of this. One of the major points of any program to reduce bycatches is promotion and acceler-ation of the development of new technologies. Given the magnitude and diversity of the bycatch problems in world fisheries, it is surprising that so few engineers and fishermen are working on the development of technological innovations. As many of the developments are costly, and require complicated experiments and tests, the flow of new ideas is not as fluid as it should be. Regulations: Some regulations may be aimed at reducing the BPUE. a) Gear or operational restrictions: Examples of this could be restrictions in mesh size, dur-ation of trawl hauls, etc. They may force changes in the gear or operations leading to lower BPUEs, either by reducing the probability of encounter with a bycatch species, or by improving the chances of that species surviving the encounter. b) Individual limits or "acceptable" ratios: Another type of regulation that can have an impact is the setting of individual bycatch limits, or "acceptable" ratios of bycatch to total catch. In either case, if the fishermen have any control on the bycatch level, they will change their behavior, area of deployment, or other variables to stay within the established parameters. In the eastern Pacific, tuna purse seiners have an annual limit to the number of dolphin that can be taken, and if reached, they have to stop fishing for tunas associated with dolphins. c) Partial closures: if some areal or temporal strata have much higher bycatch rates than others, closures of those strata should result in lower average BPUEs. If effort can be re-distrib-uted to other strata, the gains made may not be accompanied by losses in effort or in catches. d) Incentives: not all fishermen are equally skilled at handling their gear and boats, or at making decisions, and not all are equally moti-vated. Individual limits or "acceptable" ratios can be considered as incentives, but there are other possibilities. A system of positive and negative incentives, that would reward the fishermen who contribute less to the problem and penalize those that are less apt or motivated is a good option to promote the reduction in BPUEs, by allowing the best fishermen (from the point of view of the bycatch) to fish more than those who are less skilled or less motivated. In the extreme case, weeding out the fishermen who cause a disproportionate part of the problem should result in lowered BPUE averages. The incentive system should also promote the devel-opment of new techniques, by conferring an 70 economic advantage to those that can find better ways of fishing. The individual vessel mortality limit is an example of a "selective" mechanism that rewards the better operators, but there are many other possibilities, including extended seasons, higher catch limits, access to desirable areas, etc. Training: when there are maneuvers or pro-cedures, or some devices that can reduce bycatches, it is possible to train captains and crews of fishing boats to use them effectively. One of the main tasks of the scientists working on bycatch problems is the identification of causes and conditions that lead to bycatches. When a significant database is available for analysis, the main factors causing the problems can be defined, solutions can be selected by scientists, engineers, and fishermen working together, and the information can then be trans-ferred to the fishermen to serve as a basis for improving their decision-making regarding the deployment of the gear and the form it is used. At the risk of being too obvious, it should be stated that it is crucial to find out what causes bycatches, and which are the conditions that produce or intensify the problem, and which conditions reduce or eliminate it. Observer programs Observer programs are usually considered as a way to monitor bycatches, or to verify compli-ance with regulations, but the role of observer programs in helping identify the problems is frequently ignored. Bycatches result from a combination of environmental, biological, eco-logical and gear factors. To identify them, and to assess their relative importance is vital to under-take the measures needed to mitigate the prob-lems. Research programs and management actions should be based on solid scientific facts. Observer programs that are designed to be a tool in the search for solutions can provide the data required. Given the large number and complexity of the factors that can be involved, extensive databases are required. To illustrate this com-plexity, in the eastern Pacific tuna fishery the following factors have some effect on incidental mortality rates: species of dolphin, area, size of dolphin herd, size of tuna school caught, time of day, presence of strong currents, malfunctions on the equipment, use of a rescue raft, condition of equipment (repair, alignment, etc.), and of course the skill and motivation of the skipper and crew. THE LINES OF DEFENSE AGAINST BYCATCH PROBLEMS 1) Selectivity: "catch only what you want. It is necessary to devote more effort to the design and testing of new or improved gear. Studies of the target and bycatch species, may suggest gear improvements or alternative ways of fishing. In die case of active gear, better information on the species and size composition of the targets prior to capture may help reduce the waste by identifying schools that have high bycatches. More information on the spatial and temporal distribution of bycatches may lead to better deployment of the gear, avoiding areas with high levels of the bycatch/total catch ratio or other problem areas. Scientists must work to identify the factors that cause high bycatches, such as environmental conditions (currents, turbidity, etc.), gear characteristics and "behavior", and behavior and ecology of the species involved. This knowledge must be transfered to the fishermen to improve their decision-making processes. Fishing logbooks may be used for some of the needed studies, but the experience from the eastern Pacific tuna fleet suggests that there is no substitute for an exten-sive observer program. 2) Release: "if you caught it and don't want it, release it alive." Because of the characteristics of many types of fishing gear, the incidental capture of unwanted species or individuals may be unavoidable, so the second line of defense against the bycatch problems is to develop ways to ensure that as much as possible of the bycatch is released unharmed. This may require modifications of the gear itself, of the way it is used, of the way the catch is brought aboard or discarded, of the way the bycatch is handled on deck, etc. Procedures or devices that allow the pre-sorting of the catch, while they are still alive and unharmed, would result in a selective fishery even if the gear itself is not. 3) Utilization: "if you caught it and killed it, use 71 it." Some of the species that are considered targets today, were bycatch a few years ago. The devel-opment of markets for bycatch species may help reduce the impacts on the marine ecosystem. Although an individual discarded at sea will be recycled faster than one utilized, if the utilization of these discarded individuals replaces others that will not be fished, then it may be better to take advantage of the ecological costs already incurred by the fishing operations (e.g. physical impacts on the habitat, pollution, etc.) The opening of markets for new species may release the pressure on the stocks that are the favorite targets today, and the effect of this may be beneficial from the ecosystem point of view. However, if the human population continues to grow at the current rates, all new target species will progressively become more fully exploited or, in some cases overexploited, so this solution depends on reaching some controls on that growth. The same can be said of most other proposed solutions; continued increases in the levels of effort will eventually nullify any gains achieved through technology, training, etc. A more detailed treatment of these "lines of defense" can be found in Hall (In Press). CHALLENGES FOR SCIENTISTS Many of the scientific questions that the bycatch problem generates should be answered if and when we obtain a thorough understanding of the way the ecosystem functions. Unfortunately, we are lacking that understanding, and we are often left with only intuitions, which are frequently wrong. If we try to analyze the processes that follow the development of a fishery in an undis-turbed ecosystem, simply viewing the fishermen as a new predator entering that system, we can ask ourselves some questions about its impact and influence on it, given the similarities and differences between a fishery and a natural predator. The coexistence of natural predators and prey has been fine-tuned by evolution; both form part of a system with fekl-back mechan-isms, and different types of controls. However, even natural systems have "catastrophic" events, such as an invasion by an exotic species, an epidemic of some disease, etc., that may move the system toward new equilibrium points, or from one instability to another. In what follows, I include some questions that may be pertinent to understanding the ecological impacts of the fisheries. 1) A new fishery develops in an area, which is equivalent to a new predator entering the system. Regardless of the trophic level it is exploiting, the new predator "population size" (effort, not fleet size) is not controlled by its own predators. The predator may take its prey high in the food web (e.g. some sharks and tunas) or at much lower levels (e.g. clupeoids, krill). With time, several fisheries may develop, in which several levels may be harvested simul-taneously. What are the differences in the eco-system response to fisheries which harvest species at different trophic levels? Is an ecosys-tem more stable when many levels are exploited at the same time? 2) Fisheries usually take a narrow range of prey items; some species and sizes are selected, but the selectivity is variable depending on the gear, the fish community, the habitat, etc. In general, fisheries have different selectivity than "normal" predators. How does the selectivity of the predator influence its impact on the system? Is a selective fishery better, from the point of view of ecosystem stability, than a non-selective one? Shouldn't our management systems tend toward "proportional" utilization of the different levels of a food chain rather than putting all the pressure in a narrow size range of one or a few species? 3) The biomass taken by the fisheries is removed from the system (of course changing the boundaries and the definition of the system); occasionally it may end up in a different ocean basin (i.e. some tuna from the eastern Pacific is canned in Thailand, Puerto Rico, or Italy). The wastes from fish processing operations frequently end up in garbage dumps on land, and the fish products themselves may be consumed in distant locations. Natural predators, on the other hand, excrete, secrete, defecate, reproduce, and die in the same ecosystem where they feed; the recycl-ing of the prey is "local." Which are the conse-quences of these differences? 4) The species and size composition of the 72 community are altered. Biomass is redistributed among species. If the fishery is directed toward a "small" or a "large" species, or toward small or large individuals of the target species, it may affect the average size of the individuals in the community. What happens in a community where we reduce (or increase) the average size of its individuals? 5) The fishing boats "forage" in groups, in a contagious pattern, so the prey removals are not uniformly distributed in space. There are also natural predators that do that, but the fisher-men may share information on prey abundance over much longer distances than other predators. If the information is accurate, they concentrate the effort in the areas of high prey abundance. The spatial distribution of prey densities is altered, driving the distribution toward uniform-ity. What happens when not only the abundance of a prey is reduced but also its spatial distribu-tion is modified? 6) Even though the prey species can renew its numbers, there are time delays caused by "generation time" and by seasonalities in repro-duction. During these periods there are "biomass gaps," unless other species fill them. Which are the short-term responses of different species to the removal of biomass caused by an intense fishing season? 7) Some fisheries are quite wasteful, and the discards generate opportunities for scavengers. Variable biomasses are added to the water column or to the benthos as leftovers from fishing. The spatial distribution of these leftovers is also of interest (concentrated in a single point, scattered over a line, diffuse, etc.). What hap-pens to the stability and productivity of the system, and to the cycling of different compo-nents? 8) Some species benefit from the activities of the fishery (stealing prey from nets or hooks, picking up drops from longlines, etc.). Those species receive a subsidy from the fishery. This advantage may result in the competitive exclu-sion of other species, or at least in a shift of the species proportions. Are these subsidies a threat to ecosystem stability? Should action be taken to reduce or eliminate the subsidies? 9) Bycatches affect some species of the community more than others, so shifts in the species composition and proportions should be expected from this source. What are the charac-teristics of a species that make it more vulner-able (or less vulnerable) to the fishing oper-ations? 10) Some fishing activities disturb the habi-tat: e.g. noise, turbidity affected by bottom trawling, pollution, etc., that may limit the use of the habitat by other species, or affect them in other ways. Are the consequences of these impacts long-lasting? Do we have "chronic-trawling" communities, etc.! 11) Considering that all ways of fishing have some ecological impacts, how do we compare the impacts of different techniques or gears? Here we should consider at the same time the effects of bycatches, subsidies to certain species, damages to the habitat, energy use, etc., and the productivity of the fishery. Table 1 shows, in very crude terms (aggregations of species, no considerations of size, sex, reproductive condi-tion, etc.), the costs, in terms of bycatches, of producing 1000 tons of yellowfin tuna by purse-seining in three different ways. How do we decide which is the best (or least worse) way to fish? If the bycatch is composed of individuals of the same species, we can compare the impacts of different gears or techniques on the basis of the age, sex, size, reproductive value, social posi-tion, genetic characteristics of the bycatch. For instance, a technique that produces some bycatches of pregnant females may be compared to another that causes higher mortalities of immature males. A good understanding of the population dynamics of the species would sug-gest an answer based on whatever impact is easier to reverse, if that should prove to be necessary. But if we need to compare individuals of different species, we must add other factors such as population abundance, conservation status, trophic level, "vulnerability," etc. The answers are not trivial, and our lack of knowl-edge of many of these parameters, and of the functioning of the ecosystems, makes them even more difficult and uncertain. For simplicity, I have carefully avoided the introduction of genetic/evolutionary conse-quences of fisheries. But in reality, the fisheries 73 Table I: Bycatches in numbers of individuals and discards of yellowfin (in tons) per 1000 ions of yeliowfin loaded for the differcni types of sets. The numbers in parenthesis are sample sizes. SdwoiSM Leg Sets MpUaSm ta-UITI ill ? 7021 ImmTMn Dolphins <M U MS Saull MM SOJBU lJOMTLS 9.0234 Mshi euhl 4U 1M2M U Sharks S40J 1MU 43.9 Wako. 1J US2J U Ralafcaw rvnnen u au . Other small fish aoj usu 2L1 till fish a.r UX7 4.1 Yrtawtaa cu 234.1 ?LT Sea fesrtltt u u a* Other large fiak u MU -Trigger fish t i l U I U Discards of Yetlewfin tun 1) lis 3*9.1 M are powerful selective forces that have been operating for many decades, so these conse-quences should not be ignored. Perhaps many of these questions, and some new ones, should be examined with this in mind. Some research priorities concerning bycatches for the coming years (in no particular order): i) Estimation of the quantity and composition of the bycatches. Development of programs to monitor bycatches, and of instruments to assess collateral mortality. ii) Inclusion of bycatch and discard informa-tion in management models and decisions. iii) Behavior and ecology of target and bycatch species that may influence capture or release. iv) Fate of bycatches: ecological impacts and cycling of the material discarded by the fishery. v) Utilization of bycatches: new products or new uses. vi) Species subsidized by the fishery's oper-ations (facilitated predation, scavenging on wastes, etc.) as an additional source of ecosys-tem instability. vii) Physico-chemical characteristics of fishing gear and their properties to attract or repel different species: detection and perception of the gear. viii) Studies to assess the "relative value" of individuals of different sizes or species to com-pare the impacts of different ways of fishing. ix) Assessment of the overall ecological impacts of different ways of fishing, encompass-ing the effects of bycatches, subsidies to species, damage to the habitat, energy use, pollution, etc. CHALLENGES FOR MANAGERS Putting together teams of fishermen, gear engin-eers and behaviorists to find the technical, regulatory or educational solutions to the prob-lem (Hall, In Press). Developing international programs to pool technical expertise and resources. Developing multidisciplinary teams to assess the ecological impacts of different fisheries to have a clear idea of the relative costs of available or proposed alternatives, and implement mangement plans based on those assessments. To find ways to continue using the resources, while at the same time beginning or intensifying the effort to reduce the "side effects", the eco-logical impacts of the fisheries. Of special importance is the development of programs containing positive and negative incentives, and emphasizing individual responsibility. These programs should be fair and equitable and based on the best science available. CHALLENGES FOR FISHERMEN Fishermen will have to lead the way in the development of improved or alternative ways of fishing. When society sets limits on their activ-ities, they will have to develop the innovations needed to survive under those limits. This will require both creativity and financial commit-ments (investments). The industry will have to change in the direction of organizing continuous programs to tackle the different problems facing it. In the same way other industries set aside Research and Development funds to produce or keep up with technological advances, fishermen will have to set up a system to finance the needed research. Fishermen will have to find ways to marker some of the species that are incidentally caught. 74 or change the way they operate to utilize them better. Fishermen will have to learn to deal with the ecological problems generated by the fisheries before they get to the critical level that requires painful actions to mitigate them. They have to understand and accept, that the sustained use of marine resources requires the maintenance of a healthy ecosystem, and that management actions with that objective are in their best interest, even if the short term effects may be negative to their businesses. CHALLENGES FOR ENVIRONMENTALISTS Most of the campaigns related to bycatch prob-lems have been centered on the "charismatic megafauna" involved. The public reaction to dolphins is very different from their reaction to sharks or mahi-mabis. However, the ecological significance of a bycatch problem is not corre-lated to the emotional appeal of the species in question. It is necesary to educate the public so that it outgrows the purely emotional approach based on "cuteness," fears, prejudices, and anthropomorphic concepts and replace it with one which is more rational and science-based. It is impossible to conserve an ecosystem if your management actions are focused only in provid-ing full protection to a single species. Environ-mentalists should lead this change. Environmental groups have played a very signifi-cant role in bringing issues to the attention of the public, which has proved decisive to generate laws and regulations that have been valuable in some cases to solve or mitigate ecological prob-lems. However, the proliferation of problems coupled with reduced government budgets has resulted in a growing number of unresolved crises. Environmental groups should become part of the solution of the problems rather than just denouncing them. This role could be fulfilled in many different ways, from funding research projects to volunteer work. However, one of the more critical needs to solve bycatch problems is to bring to the attention of a much broader sector of society that includes engineers, scientists, inventors, gadgeteers, etc., the technical issues that need to be addressed and solicit ideas and proposals for solutions. The role of involving the public in the challenge of finding solutions that can allow the continuous use of the resources while at the same time mitigating or eliminating the bycatch problems, is one where environ-mental groups can be more effective than any other sector involved. REFERENCES Alverson, D.L., Freeberg, M.H., Pope, J.G. and Murawski, S.A. 1994. A global assess-ment of fisheries bycatch and discards. FAO, Fisheries Technical Paper. No. 339. Rome, FAO, 233 p. Au, David. 1991. Polyspecific nature of tuna schools: Shark, dolphin, and seabird associ-ates. Fish. Bull., U.S. 89:343-354. Hall, M.A. Unpub. ms. An ecological view of the tuna-dolphin problem. Hall, M.A. In Press. Strategies to reduce the incidental mortality of marine mammals and other species in fisheries. Developments in Marine Biology, Vol. IV. Elsevier Publ. Joseph, J. 1994. The tuna-dolphin controversy in the eastern Pacific Ocean: biological, econ-omic and political impacts. Ocean Develop-ment and International Law, 25(1): 1-30. Merino, J.M. 1991. La pesca desde la prehistoria hasta nuestros dias. 2a. edition. Servicio Central de Publicaciones del Gobierno Vasco. Depto. de Agricultura y Pesca, Administration de la Comunidad Autonoma del Pais Vasco. 494 pp. Punsly, R.G., Tomlinson, P.K. and Mullen, A.J. 1994. Potential tuna catches in the eastern Pacific Ocean from schools not associated with dolphins. Fish. Bull. 92:132-143. SECTION VI SUMMARY OF WORKING GROUPS 77 SUMMARY FROM THE TECHNOLOGY WORKING GROUP Steven J, Kennelly (Chairperson) ? ? ? INTRODUCTION Towards the end of the first day of the workshop (during which invited speakers presented their papers), several groups of issues were identified as being central to the overall field of by-catch in fisheries. These were policy-related issues, ecosystem considerations and technological issues. We decided to separate into working groups to discuss each of these during the second day. The following is a summary of the things discussed in the technology working group. The key issues that were identified as being important for this particular working group were: (i) incentives and support for change in tackling by-catch problems; (ii) escape methodologies; (iii) survival of discards; and (iv) ways to accelerate technological developments. INCENTIVES AND SUPPORT FOR CHANGE IN TACKLING BY-CATCH PROBLEMS Discussion concerning these issues naturally dealt with attitudinal perspectives of the by-catch problem in commercial fisheries. We felt that an absolute pre-requisite to solving by-catch problems is to have commercial fishers WANT to solve these problems. This is particularly important within the overall objective of solving by-catch problems through technological change using a combination of scientific rigor and fishers' unique practical knowledge of their particular gear and fishery. We felt that such a combination of expertises would be the most expeditious and efficient way to tackle the prob-lems. We decided that this goal requires the appropri-ate attitude to be held by all scientists who are dealing with the problem and at least a few fishers (not necessarily all or even a majority of fishers in the first instance because once success-ful, other fishers will soon "follow the leader"). For fishers to improve attitudes we discussed how they need to be aware of any monetary benefits to be gained from solving by-catch problems in addition to the often very real advantage that, in the absence of change, the longevity of the entire fishery could be at stake. Scientists who work in the by-catch field need to improve and maintain a strong working relation-ship with fishers by (in the first instance) earning fishers' respect at sea. Once this sort of liaison is developed, more formal meetings and small workshop fora can be used to dis-cuss/disseminate solutions. We felt that large meetings with lots of scientific information and other extraneous inputs would not be very pro-ductive in terms of aquiring fishers' knowledge of how to deal with by-catch problems through technology. ESCAPE METHODOLOGIES A common theme throughout our working group was that technological solutions to by-catch problems require fishery-specific answers. We therefore concentrated on a few disparate examples and tried to avoid the solutions dis-cusses! on the first day of the workshop for trawl (separator grids, square-mesh panels, etc.) and purse-seine fisheries (operational procedures combined with modified purse-seines). The key by-catch problems with the rock sole fishery involves another flatfish (halibut) and king crabs. We discussed several ways that the crabs may be excluded from rock sole gears using panels, chutes etc. but could not think of any way to fish selectively for one species of flatfish whilst excluding another. Possible alternative solutions to this difficult by-catch problem included having by-catch limits placed on individual vessels rather than the whole fleet; operational changes in terms of the places and times of fishing; and if by-catches of halibut could not be reduced, then their on-deck mortal-ity may be reduced by getting the fish back into the water as soon as possible. The latter approach is complicated by the requirement that detailed measurements of by-caught fish have to be taken (see below). Longline fisheries have by-catch problems that involve sharks, sea-birds and turtles. We dis-cussed several ideas that have been (or could be) tried to reduce such by-catches. These included pingers (sonic devices) to scare off sharks and turtles, streamers (acting like scare-crows) to 78 scare off birds, setting lines in deeper water, using hook sizes and baits that are more selective for the target species. Gill netting was discussed as having several attributes that can be modified to reduce by-catches. These included mesh size, hanging ratios, twine strength, the materials used and the depth of setting. Gill netting for salmon was an interesting example: An innovation in the gear and method of setting has been developed and is known to be successful in reducing the unwanted by-catch of another salmon species but has not been accepted by industry because the correct attitude is lacking. It was discussed that there is a clear need for the correct incentive to be provided to the fishers in this fishery which may be a fishery-longevity issue: i.e. no innovation = no fishery. Ghost fishing (when fishing gear is lost but continues to fish) was discussed as a major problem in many fisheries and we discussed the various materials that could be used and/or avoided. The chief problem, however, was that using nets etc. that corrode quickly once lost also means increasing the costs to fishers in terms of replacement and maintenance. A regulatory solution to ghost fishing was men-tioned where all nets used in a fishery had to be labelled and fines were imposed on fishers if their gear was found but its loss was unreported. SURVIVAL OF DISCARDS Two issues were discussed here: (i) survival of discards on deck after "by-capture"; and (ii) the survival of by-catch that has been excluded through various gear modifications (e.g. grids, square-mesh panels etc.). It was noted that the survival of finfish by-catch on deck may be enhanced through the use of recovery tanks (i.e. sorting the catch in water) and this has been quite successful in some Aus-tralian prawn trawl fisheries. Other operational possibilities may involve returning the by-catch to the water as soon as possible although this is not the case for some species like turtles who may drown if returned to the water immediately after capture. Some types of specialized resusci-tation may be required for such species. It was also noted that for the by-catch of halibut in the rock sole fishery, certain data collection methods may lead to increased on-deck mortality by prolonging the time spent out of water. Some abbreviated form of data collection may be needed in such circumstances. We discussed the possibility that the exclusion of by-catch through modified gears during their actual fishing operation (e.g. grids, square-mesh panels, etc. in trawl nets) may cause damage and consequent mortality of by-catch that goes undetected. That is, whilst such excluders remove the by-catch from the net and therefore the deck, they may not be doing much in terms of saving fish if the fish die as a result of pas-sing through, between or over some structure in the net. This is a common argument concerning these sorts of gear modifications and what research that has been done has usually shown quite small mortalities due to gear modifications. These results are, however, usually species-specific - some species show quite high mortal-ities. It was noted that the materials used to make modifications in fishing gear is critical to minimizing such mortality. It was also discussed that, apart from physical damage caused by gear modifications, excluded by-catches may be subjected to enhanced predation by certain species. The example discussed was that predatory sharks may follow trawl nets and position themselves directly over escape panels and grids so that they can easily feed on the excluded by-catch. Methods for quantifying this problem were discussed which basically involved video cameras determining if this is a major or minor problem. WAYS TO ACCELERATE TECHNOLOGICAL DEVELOPMENTS It was noted that funding for research into the technological aspects of the by-catch issue was very small. There is a very real need for more money to be made available for equipment like flume tanks, underwater video gear, netsons, etc. to facilitate the development of by-catch reducing technology. In addition to direct government funding, other possible sources for such funding were noted to be: levies on indi-vidual fisheries (not just the "by-catching" fishery but any fisheries that may benefit from reducing by-catches - e.g. recreational fish-eries); taxes on seafood; and extra quota being given to fishers who develop or use by-catch reducing technology. In keeping with our conclusions from the first issue we discussed - that industry should be actively involved in all technological develop-ments from the earliest possible stages (see above) - we noted that it was important that any additional funding for by-catch research should be made available to industry and scientists in the appropriate manner. Chartering industry vessels to do the field work instead of maintain-ing expensive government research ships was noted to be an excellent way to facilitate such research. It was felt that such moneys (if gener-ated specifically for technological research into by-catch reduction) should be administered by the relevant scientists and fishers - keeping it separate from general government revenues. GENERAL COMMENTS / CONCLUSIONS Several general points were made during the session: Each fishery that was discussed was said to be "a different type of fishery", highlighting the fishery- and species-specific nature of by-catch problems, particularly with respect to technologi-cal issues. There is a need to overcome any suggestion of "scientific arrogance" in dealing with fishers on these issues so that we can adhere to: The best course for solving by-catch prob-lems is to involve industry in all technological developments from the earliest possible stages. Funding for research into technological developments to reduce by-catches is small and more needs to provided and/or raised. Such moneys need to be distributed to the approriate scientists and fishers so that joint research can be facilitated. 80 SUMMARY FROM POLICY AND ATTITUDES WORKING GROUP A.W. Trites (Chairperson) Bycatch is of concern to many different people for many different reasons. For some, the central issue is one of waste. Others are primar-ily concerned with the health of the ecosystem and the negative effects on the productivity of both targeted and non-targeted fish stocks. Economic losses are another concern, whether they be from handling costs or loss in numbers offish available to other vessels. Finally, many people are only concerned with the ethics of catching and killing non-targeted species, par-ticularly when the bycatch consists of sea turtles, sea birds, and marine mammals. Differences in attitudes and perceptions about bycatch are likely rooted in social and cultural values. The developed world tends to take a protectionist position, desiring to either protect the health of the ecosystem, or protect traditional commercial and recreational fisheries, or protect the birds, turtles and marine mammals of the oceans. Such a view of bycatch is in sharp contrast to that of the developing world who tend to strive towards full usage and reduced waste. Bycatch consists of species that are discarded and those that were mistakenly caught but kept anyway. Often it occurs because fishermen are involved in race-fisheries. They do not have the time to fish more carefully or to develop new methods. The bottom line for the commercial fishermen is the profit margin. They are econ-omically driven to fish for dollars. Policies that will reduce excessive bycatch levels tend to evolve outside the scientific arena. To date, policies have been evoked to protect certain valuable fisheries (such as for halibut and salmon) and certain top level predators (e.g., the U.S. Marine Mammal Protection Act). More policies will likely be proposed as the slowly evolving attitudes of the public begin to harden. areas fished. The second is to place the onus on the fishermen to reduce bycatch through econ-omic incentives and penalties. For example, rewarding fishermen with additional quotas if they catch clean will encourage fishermen to develop better fishing methods. Individual Fish-ing Quotas is one means that may allow fisher-men the time to develop new and better tech-niques. Similarly, requiring all vessels to land all bycatch at no cost will also be incentive for fishermen to actively seek means to reduce their bycatch levels. In some cases, successful solutions will require technological changes. In others it may mean the development of new markets to distribute the bycatch. Some fishermen may need training. All will require information feedback. The bottom line to successful solutions will be fish-ery-specific research, monitoring and documenta-tion. No single policy is likely to apply to all fish-eries. Nevertheless, there are two basic approaches that can be considered to reduce bycatch. One is to impose legislative regulations and restrictions on gear, effort and time and LIST OF PARTICIPANTS Barry Ackerman Department of Fisheries and Oceans Suite 400 - 555 W. Hastings Vancouver, B.C. V6B 5G3 CANADA Tel: (604) 666-9033 Fax: (604) 666-8525 Dayton AJverson Natural Resources Consultants, Inc. 4055 21st Avenue West, Suite 200 Seattle, WA 98199 USA Tel: (206) 285-3480 Fax; (206) 283-8263 Beth Babcock University of Washington School of Fisheries, WH - 10 Seattle, WA 98195 USA Tel: (206) 543-7384 Michael Baumann Dept. of Oceanography University of British Columbia 6270 University Blvd. Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 224-5757 Fax: (604) 822-6091 Joe Blum American Factory Trawler Association 4039 21st Avenue West, Suite 400 Seatde, WA 98199 USA Tel: (206) 285-5139 Fax: (206) 285-1841 Ramon Bonfil Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Alida Bundy Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Ying Chuenpagdee Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-0618 Fax: (604) 822-8934 Scott Cope RR # 1, Site 4, Comp, 45 Crescent Valley, B.C. V0G 1H0 CANADA Tel: (604) 355-7811 Jane DicCosimo North Pacific Fishery Management Council 605 W 4th Ave., Suite 306 Anchorage, AK 99501 USA Tel: (907) 271-2809 Fax: (907) 271-2817 Martin Esseen Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-0618 Fax: (604) 822-8934 John Gauvin American Factory Trawler Association 4039 21st Avenue West, Suite 400 Seattle, WA 98199 USA Tel: (206) 285-5139 Fax: (206) 285-1841 Martin Hall Inter-American Tropical Tuna Commission c/o Scripps Institution of Oceanography 8604 La Jolla Shores Drive La Jolla, CA 92037 - 1508 USA Tel: (619) 546-7100 Fax: (619) 546-7133 Steven Hansen University of British Columbia South 17 B6, Gage Tower Residences Vancouver, B.C. V6T 1Z1 CANADA Tel: (604) 228-4668 Lorenz Hauser School of Biological Sciences (East) University of Wales, Swansea Swansea SA2 8PP U.K. Tel: (1792) 205-678 ext 4614, 4603 Fax: (1792) 295-447 Trevor Hutton Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Laure Jansen Arctic Alaska Fisheries Corp. P.O. Box 79021 Seattle, WA 98119 USA Tel: (206) 298-4010 Fax: (206) 298-4186 Steve Kennelly Fisheries Research Institute . 202 Nicholson Parade P.O. Box 21 Cronulla, NSW 2230 AUSTRALIA Tel: (02) 527-8411 Fax: (02) 527-8576 82 Peter Larkin North Pacific Universities Marine Mammal Research Consortium, Room 18, Hut B-3 6248 Biosciences Rd. Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-8181 Fax: (604) 822-8180 Bruce Leaman Pacific Biological Station 3190 Hammond Bay Road Nanaimo, B.C. V9R 5K6 CANADA Tel: (604) 756-7176 Fax: (604) 756-7053 Taj a Lee Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax. (604) 822-8934 Mary Sue Lonnevik Universal Plans, Inc. 2839 - 14th West Suite 401 Seattle, WA 98119 USA Tel: (206) 281-8643 Fax: (206) 281-8643 Douglas March Deep Sea Trawlers Association of B.C. Unit 2, 11771 Horseshoe Way Richmond, B.C. V7A 4V4 CANADA Tel: (604) 275-6944 Fax: (604) 275-6949 Harold Medina 3128 Villa Caliente del Sol Jamul, CA 91935 USA Ron Membeiy Vancouver Aquarium P.O. Box 3232 Vancouver, B.C. V6B 3X8 CANADA Tel: (604) 631-2523 Fax: (604) 631-2529 Morris Mtsambiwa Lake Kariba Fish. Res. Inst. Box 75, Kariba ZIMBABWE Tel: (263) 61-2936 Fax: (263) 61-2938 Chad Nelson School of Community and Regional Planning University of British Columbia 6333 Memorial Road Vancouver, B.C. V6T 1Z2 CANADA Tel: (604) 822-4409 Fax: (604) 822-3787 Tom Nishida National Research Institute of Far Seas Fisheries, Fisheries Agency of Japan 5-7-1 Orido Shimiza City, Shizuoka 424 JAPAN Tel: (0543) 34-0715 Fax:(0543)35-9642 James Njiru Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Geir Oddsson University of Washington School of Fisheries, WH - 10 Seattle, WA 98195 USA Tel: (206) 543-7384 Bill Patton University of Washington School of Fisheries, WH - 10 Seattle, WA 98195 USA Tel: (206) 543-7384 Jose Antonio Perez-Comas University of Washington School of Fisheries, WH - 10 Seattle, WA 98195 USA Tel: (206) 543-7384 Tony Pitcher Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 David Ramm Dept. of Primary Industry and Fisheries Fisheries Research & Development Branch GPO Box 2268 Darwin, NT 0801 AUSTRALIA Tel: (089) 897-648 Fax: (089) 813-420 Paul Ryall Department of Fisheries and Oceans 3225 Stephenson Point Road Nanaimo, B.C. V9T 1K3 CANADA Tel: (604) 756-7279 Fax: (604) 756-7232 Lauri Sadorus International Pacific Halibut Commission P.O Box 95009 Seattle, WA 98145- 2009 USA Tel: (206) 634-1838 Fax: (206) 632-2983 Silvia Salas Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Joel Sawada Provincial Fisheries Branch 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 660-1812 Fax: (604) 660-1849 David Sax by 4727 S. Picadilly W. Vancouver, B.C. V7W 1J8 CANADA Tel: (604) 685-4977 Fax: (604) 926-2620 Janet Smoker Fisheries Information Services 20007 Cohen Drive Juneau, AK 99801 USA Tel: (907) 789-5580 Fax: (907) 789-5580 Catherine Stewart Green Peace 1726 Commercial Drive Vancouver, B. C. V5N 4A3 CANADA Greg Taylor Ocean Fisheries Ltd., P.O. Box 460 Prince Rupert, B.C. V8J 3R2 CANADA Tel: (604) 624-9635 Fax: (604) 627-7966 Joe Terry National Marine Fisheries Service Alaska Fisheries Science Center NO A A F/AK C2 7600 Sand Point Way NE Seattle, WA 98115 USA Tel: (206) 526-1253 Fax: (206) 526-6723 Keith Thomson Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-3025 Fax: (604) 822-8934 Andrew Trites North Pacific Universities Marine Mammal Research Consortium, Room 18, Hut B-3 6248 Biosciences Rd. Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-8182 Fax: (604) 822-8180 Judson Venier Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-2731 Fax: (604) 822-8934 Carf Walters Fisheries Centre University of British Columbia 2204 Main Mall Vancouver, B.C. V6T 1Z4 CANADA Tel: (604) 822-6320 Fax: (604) 822-8934 Brad Warren National Fisherman 4055 21st Ave. West Seatde, WA 98199 USA Tel: (206) 283-1150 Fax: (206) 286-8594 Eric Wickham 4210 Blenheim St. Vancouver, B.C. V6L 2Z4 CANADA Tel: (604) 734-0632 Fax: (604) 734-0623 Carmen Wiseman University of Washington School of Fisheries HF- 15, 1140N.E. Boat St. Seattle, WA 98195 USA Tel: (206) 616-1087 Fax: (206) 685-3275 85 David Witherell North Pacific Fishery Management Council 605 W 4th Ave., Suite 306 Anchorage, AK 99501 USA Tel: (907) 271-2809 Fax:(907) 271-2817 Keith Wolf Washington Department of Fish and Wildlife 600 Capitol Way North Olympia, WA 98501 - 1091 USA Tel: (206) 902-2717 Fax: (206) 902-2949 85 FISHERIES CENTRE WORKSHOP SERIES The Fisheries Centre organizes workshops concerning fisheries-related topics and issues of current interest. We aim at developing the knowledge and tools required to study particular problems arising in fisheries. Also, we focus on enhancing understanding of natural ecosystem. Our workshops are designed to be as practical as possible. Thus they usually include some practical work and/or model development, as well as presentation of papers and/or talks by experts in the field. The workshops have an informal format and are held in small groups to generate discussion and to provide a comfortable working environment. The report from each workshop is edited and published in the Fisheries Centre Research Report series which is distributed among various institutions and organizations the for and available on request. Outputs from workshops are formulated into plans future research in each area. We welcome participants from around the world, and from all fisheries institutions/organizations, including the private sector. Graduate students are particularly encouraged to attend and participate in our workshops. In general, all the workshops in this series are held at the Fisheries Centre on the UBC campus. However, FC resources and personnel have experience in tailoring workshops to suit particular interests and can be held elsewhere. PC Workshops 1993 Commercial Whaling - The Issue Reconsidered (Fisheries Centre Research Reports 1993, Volume 1, Number 1) Decision Making by Commercial Fishermen: a missing component in fisheries management? (Fisheries Centre Research Reports 1993, Volume 1,Number 2) FC Workshops 1994 Bycatches in Fisheries and Their Impact on the Ecosystem (Fisheries Centre Research Reports 1994, Volume 2, Number 1) FC Workshops 1995 Impact of Changes in North Pacific Oceanographic Regimes on Coastal Fisheries (Fisheries Centre Research Reports 1995, Volume 3, Number 1) Graduate Student Symposium on Fish Population Dynamics and Management (Fisheries Centre Research Reports 1995, Volume 3, Number 2) 86 Upcoming FC Workshop 1995-1996 Workshop # 1 : A Mass-Balance Model of Trophic Fluxes in the North Pacific A one-week workshop is proposed during which 12-15 invited participants would assemble the elements required for mass-balance models of trophic fluxes in the North Pacific Ocean, with emphasis on the waters off British Columbia and Alaska. Date: November 6-10, 1995. Workshop # 2: Harvesting Krill: Issues and Potential A three-day practical workshop focusing on the issues raised by harvesting of krill, including how to assess sustainable krill harvests, ecological implications, harvest methods, markets and utilization. The intended output of this workshop will be a volume in Chapman & Hall Fish and Fisheries Series. Date: November 14-16, 1995. Fisheries Centre Symposium This three-day symposium will focus on various issues of fisheries on a national and international level. The symposium will be led by members of the Fisheries International Advisory Council. Date: February 21-23, 1996. If you would like to know more about our activities, or to receive copies of Fisheries Centre Research Reports, please write to: Ying Chuenpagdee FC Workshop Coordinator 2204 Main Mall Fisheries Centre, UBC Vancouver, B.C. V6T 1Z4 Tel: (604) 822-0618 Fax: (604) 822-8934 e-mail: ying@fisheries.com For request on a copy of the Fisheries Centre Research Reports, please enclose a cheque or money order of CAN $10.00, made payable to "University of British Columbia", to cover production and handling costs. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.52383.1-0074770/manifest

Comment

Related Items