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A limnological study of a series of five lakes in the interior of British Columbia and the effects of… MacPhee, Craig 1949

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A LIMNOLOGICAL STUDY OF A SERIES OF FIVE LAKES IN THE •INTERIOR OF BRITISH COLUMBIA AND THE EFFECTS OF ROTENONE ON THE FAUNA OF TWO OF THESE LAKES A Thesis Submitted in Partial Fulfilment of the Requirements for the Degree of Master of Arts in the Department of Zoology The University of British Columbia Apri l , 1 9 4 9 . - by -Craig MacPhee A B S T R A C T A comparative, limnological study of five, small, eutrophic lakes in the Interior of British Columbia was made over a period of two summers. Detailed morphometrical, physical, chemical and biological data are given. The effect of a rotenone base compound on the fauna of two. of these lakes is shown both qualitatively and quantitatively by comparing them with the faunas in other lakes. A complete eradication of the fish in the lakes was obtained. Certain species of plankton and bottom organisms were kil led by the poison but sufficient numbers survived to re-populate the lakes. The plankton populations did not revert to the previous level of abundance in the year following. The effect of the absence of coarse fish on certain shore organisms and Gladocera was indicated. T A B L E O F C O N . T E N T S A B S T R A C T , ' I N T R O D U C T I O N A C K N O W L E D G E M E N T S L I M N O L O G Y LOCATION AND GEOGRAPHY MORPHOMETRY PHYSICS Transparency . Temperature . Mean temperatures Summer heat budgets C l a s s i f i c a t i o n . CHEMISTRY Oxygen . Hydrogen Ion concentration S i l i c a t e , phosphate and i r o n FLORA AND FAUNA E7X PE.R I M E NT. A L P L A N ROTENONE AND FISHTOX. LABORATORY EXPERIMENT WITH FISHTOX . FIELD APPLICATION . . . . R E S U L T S EFFECT ON PLANKTON . . . . Apparatus and c o l l e c t i o n errors Plankton c o l l e c t i o n s Volumetric, gravimetric and enumeration data . . . 6 8 EFFECT ON BOTTOM ORGANISMS . . . . 80 EFFECT ON SHORE ORGANISMS . . . . 8 3 EFFECT ON FISH POPULATIONS . . . . 84 DISCUSSION . . . . . . . 8 6 G E N E R A L D I S C U S S I O N . . . 90 S U M M A R Y . . . . . . 9 4 C O N C L U S I O N S . . . . . . 97 AAP.P E N D I X . . . . . . . 9 8 L I T E R A T U R E C I T E D . . . . 143 I N T R O D U C T I O N Clemens (1934) and MacPhee (1948) have outlined some of the theoretical aspects of the coarse fish problem in British Columbia. The extent of predation by piscivorous fish on Kamloops trout Is not known. The effect of competition by coarse f ish on Kamloops trout is unexplored. Whether or not the young of competitor and predator f ish are more useful as food for large trout than the old are detrimental to the livelihood of small trout has not been ascertained. In an attempt to solve these problems, the University of British Columbia and the British Columbia Game Commission undertook a large-scale f ield experiment in 194-7. Five, small, alkaline lakes near Princeton, British Columbia, were chosen for the site of this research. These lakes contained eight species of f ish other than Kamloops trout. The plan of this experiment was simple. The fish in two of the lakes were kil led with rotenone and the lakes were then restocked with marked Kamloops trout. The remaining lakes were also stocked with marked fish, and were used as control lakes. In this experiment, control lakes were needed, so that In drawing conclusions, annual variations due to climatic , t r i c o n d i t i o n s might be e l i m i n a t e d . Experimental and c o n t r o l l a k e s were t h e r e f o r e chosen i n such c l o s e p r o x i m i t y t h a t l o c a l v a r i a t i o n s i n c l i m a t i c c o n d i t i o n s would be n e g l i g i b l e . A comparison of the growth and m o r t a l i t y r a t e s of the stocked t r o u t i n the experimental l a k e s w i t h those i n the c o n t r o l l a k e s w i l l show the extent of c o m p e t i t i o n and p r e d a t i o n by coarse f i s h . As a background t o t h i s problem, the author has made a comparative l i m n o l o g i c a l study of f i v e l a k e s and has shown the e f f e c t s of F i s h t o x on fauna by comparison w i t h c o n t r o l l a k e s . A c o n s i d e r a b l e p o r t i o n of the t h e s i s Is devoted to a study of the morphometrical, p h y s i c a l , chemical and b i o l o g i c a l c o n d i t i o n s of the l a k e s i n 1947 and 1948. These t o p i c s have been t r e a t e d c o m p a r a t i v e l y I n o rder to show the degree i n which they v a r i e d . The u l t i m a t e outcome of the experiment would depend p a r t l y on a knowledge of these environmental f a c t o r s . In a d d i t i o n to the study of the i n t e r - r e l a t i o n s h i p s of coarse f i s h and Kamloops t r o u t , s t u d i e s of the e f f e c t of F i s h t o x and of the consequent absence of f i s h on the fauna of the l a k e s were undertaken. T h i s work was supplemented by a l a b o r a t o r y experiment t o determine the e f f e c t of F i s h t o x on c e r t a i n organisms. T h i s t h e s i s d e a l s w i t h the fundamental aspects of the experiment. v l l A C K N O W L E D G M E N T S The author wishes to express his grateful appreciation to Dr. W.A. Clemens, Head of the Department of Zoology, for his generous guidance and supervision in this work. The author is indebted to Dr. W.S. Hoar, Professor of Zoology and Fisheries, and to Dr. J.A. Adams, Professor of Zoology, for many courtesies extended during the preparation of this thesis. The author wishes to thank Dr. P.A. Larkin, Department of Zoology and Biologist for the British Columbia Game Commission, for his helpful co-operation and personal interest in this work. The author gratefully acknowledges the special assistance given by Dr. M.Y. Williams, Head of the Department of Geology, in the interpretation of the geology of the district . Valuable criticism was tendered by Dr. V.C. Brink, Department of Agronomy, in the statistical treatment of the thesis, which the author deeply appreciates. The author is appreciatively sensitive of the efforts accorded him by fellow students in collecting material in the f i e l d . He wishes to acknowledge, also, the kind co-operation v i i i of the.members of the Princeton Fish and Game Club. Likewise, Mr. A .F. G i l l , Game Warden, merits distinct recognition for generous services rendered in the f i e l d . The author would also acknowledge the conjoint effort of the University of British Columbia and the British Columbia Game Commission for their financial assistance which made this project possible. i 1 A XiIMNOLGGICAL STUDY OF A SERIES OF FIVE L A K E S IN THE INTERIOR OF BRITISH COLUMBIA AND THE EFFECTS OF ROTENONE ON THE FAUNA OF TWO OF THESE LAKES L..IIM N.O L O G Y LOCATION AND GEOGRAPHY The five lakes comprising this study are situated east of the Cascade Mountains (lat. 49°40' N. and long. 12Q°37t W.) i n a central part of the Interior Plateau (Figure I). They l i e between an altitude of 2,500 and 3»000 feet at one of the western headwaters of the Columbia river. They form an eight-mile, north-south trending chain, lying i n the narrow, steep-walled Allison valley. Allison (Burns, Thin) lake i s the upper-most i n the chain and drains i n succession through Borgeson (Round, Square), Dry and Laird (Mackenzie, Blue, Enxako) lakes to the lowest lake, McGafferty (Blue, Green). These lakes are drained by One-Mile creek (Allison creek) which empties ten miles south of McCafferty lake into the Slmiikameen river, at a point approximately a mile below the town of Princeton, B.C. The watershed of the five lakes covers an area of some f i f t y - f i v e square miles. It i s drained by numerous, small creeks which extend finger-like into the h i l l s . During the spring run-off, these creeks are raging torrents. For the most part, during the summer and f a l l , they either dry up or become subterranean, entering the lakes as seepage. Allison lake, at the head of this series, receives, i t s water by four main drainage systems from the large, northern area of the watershed. Directly east of Allison lake rises Missezula Mountain (alt. 5*410 feet), sheltering two tiny lakes on its northern slope. These lakes give rise to Allison creek, which is seven miles long and is the longest creek in the area. It flows north for four miles, receiving water from several small lakes and creeks. It then doubles back three miles and enters the valley from a north-west direction. In 194-7, the spring run-off was light, and Allison creek disappeared into the ground before entering the lake. In 1948, the spring run-off was excessive, and Allison creek flowed into the lake for a short period. At the height of its water, the creek changed its channel on entering the valley, flooding a large hay f ie ld to form a small temporary lake approximately 0.15 square kilometers in area and 5 meters deep. The water from this lake drained out as seepage to feed Allison lake. Missezula Mountain also gives rise to two short streams which drop directly to the east shore of Allison.lake and which are usually dry in summer. North-west of Allison lake lies Pike Mountain. Between this mountain and the head of Allison lake, John Brown's creek rises from a small lake and drains the h i l l s south-east of Pike Mountain. Even during heavy run-offs, this creek never reaches Allison lake but disappears into the floor of the valley. Three miles directly north of Allison lake, to the east of the valley, a series of three lakes, known as the Hornet lakes give rise to a precipitous stream which disappears into the valley just south of Allison pass. North-east of Pike Mountain and to the west of the valley, another stream passes through Kump (Lost) lake and enters the valley at the site of three small ponds lying somewhat south of the Hornet creek location. These two creeks drain the most northerly parts of the One-Mile watershed. Like the other creeks, they become subterranean on reaching the floor of the valley. Even during flood periods, they enter Allison lake underground.! The water from Allison lake escapes mostly through seepage. In consequence, the lake may drop 2 or 3 meters below the natural overflow level of i ts outlet. By spring, the water level is usually low enough to absorb the spring run-off without overflowing. This condition existed in 194-7 when the stream-bed between Allison and Borgeson lakes was dry. During the latter part of May, 1948, extreme flood conditions occurred, and Allison lake rose at a rate of 12-13 centimeters a day and overflowed. A flow of 1 cubic meter per second, at the height of the overflow, was estimated from the amount of water that would have to leave the lake in order to keep its level constant. This overflow flooded a large meadow, about . 0 5 square kilometers in area, 2 meters deep. Then i t continued above ground along the west side of 5 the valley and entered the north corner of Borgeson lake. Borgeson lake l ies a mile and a quarter below Allison lake in an elbow of the valley. In addition to the main stream, i t is fed by Borgeson creek. This is a small creek, usually dry, which enters the north-west side of the lake. In normal years, Borgeson lake is fed entirely by seepage. During flood conditions, the outlet stream, situated at the south-east corner of the lake, flows a l l the way to Dry lake, one mile south. On its Journey, i t receives a small tributary draining the high lands to the west. During arid seasons, the stream out of Borgeson lake flows two-thirds its length and then disappears into the gravel, reappearing to form several springs at the north end of Dry lake. Besides the main drainage from Borgeson lake, a comparatively large creek drains the area south-west of Dry lake. In the spring, this creek is large and reaches the south shore of the lake, but, later in the year, i t disappears into the floor of the valley. A second, seasonal creek, much smaller than the f i r s t one, tumbles into the lower east shore of the lake. Dry lake, like Allison lake, drains largely by seepage and does not often overflow. The water level fluctuates about 5 meters, depending on the nature of the seasons. During the last week of May, 1948, the water-level rose at the rate of 17-18 centimeters a day until the lake overflowed. Usually, as in 1947, the stream bed from Dry lake to Laird lake, a mile to the south, Is dry. One small, short-lived stream precipitates into the south-west corner of Laird lake. One-Mile creek flows the year round for a distance of one and a half miles from Laird to McCafferty lake. On its course, the creek gathers two small, intermittent tributaries, one from the west and the other from the east from the southern slope of Missezula Mountain. Below McCafferty lake, One-Mile creek flows through several ponds and marshes to its Junction with the Simllkameen. Rice (1947) studied the geology of the area. Part of his introduction is as follows: "The Princeton area is underlain by a succession of volcanic rocks ranging in age from late Palaeozoic to late Tertiary; by sedimentary rocks, mostly in minor amounts, interbedded with the volcanic groups; and, by intrusive rocks ranging in composition from granite to peridotite and in age from Jurassic to late Cretaceous or early Tertiary." Dating from Jurassic or later, coast intrusions, composed mainly of reddish, coarse-grained, siliceous granite and granodiorite, cross the upper two-thirds of the valley. They surround Allison lake except for its east bank, Borgeson and Dry lakes completely and the northern half of Laird lake. Dating from upper Triasslc, varicolored lava; argillite, tuff, limestone; chlorite and sericite schist form a spur 7 which projects into the coast intrusion to the east hank of^  Allison lake. These Trlassic rocks also surround the lower half of Laird lake and McCafferty lake completely. Allison valley follows lines of faulting and in common with adjacent north-south trending valleys, has been deeply scoured by moving ice. The drainage was mainly east and west, hut during the ice age and since that time, was changed to a north-south direction, one of the results of this change• being the formation of a number of large, temporary lakes by the damming action of the ice or glacial detritus during the late Glacial period. The author could find no statement concerning the reason for the peculiar disappearance of water in the three stream beds connecting the upper four lakes. It appears likely, that the change in character of the rock types at Laird lake may be the answer. The coast intrusion is harder than the upper Triassic rocks. Glacial drift from this formation, lying on the valley floor, wears less, tending to remain more gravelly and allowing water to seep through, whereas the Triassic rocks are softer, and therefore, more subject to wear, making i t more diff icul t for water to pass through them. Thus i t would seem that the waters leaving Laird and McCafferty lakes are unable to seep through under-ground to any great extent and consequently become surface streams. From the foregoing discussion, fundamental differences of the One-Mile lakes due to geographic location are considered negligible. The lakes are a l l closely related with regard to altitude, longitude and latitude, and any consequential differences due to climate in the form of precititation, wind and insolation, must therefore be slight. It is observed that the water levels of Allison and Dry lakes fluctuate seasonally. It is noted also that Allison, Borgeson and Dry lakes are normally isolated from each other, and from Laird and McCafferty lakes except through under-ground seepage. Finally, i t is seen that the bulk of the 1 water originates north of Allison lake and eventually drains through each lake in turn to McCafferty lake. Moreover, except for three small periodical creeks, a l l the drainage comes from the coast intrusion. MORPHOMETRY Estimates of the size and shape of each lake were obtained from air photographs, Series A 9,526, Numbers 54, 55, 57, 59 and 61, procured from the National Air Photographic Library, Department of Mines and Resources, Ottawa, Canada. The scale of the photographs was computed by comparing the • distance between two points on a topographic map obtained from the Department of Lands, British Columbia. The lakes were carefully enlarged from the photographs and details of shore-line and area are shown in Figures II-VI. The locations of the various contour lines were estimated from bottom dredgings and therefore the contour lines are rough. They are more reliable for the four smaller lakes than for Allison lake. Information on the nature of the shoreline and shelves was obtained, partly from the air photographs, partly from the bottom dredgings and partly from the author's personal observations, made over a period of two seasons. Tabulated information on the morphometry of McCafferty, Laird, Dry, Borgeson and Allison lakes, and for comparative purposes of Paul lake (Rawson 1934), appear in Table I. The values are obtained directly from Figures II-VI, and computed according to definition (Birge and Juday 1914, Welch 1943) Certain values were taken directly from the Paul lake report and others were recalculated from the map, assuming the maximum length of the lake equal to 6.1 km. (3.8 mi.). The M C C A F F E R T Y L A K E . I -I0> BOTTOM SAMPLES 6 - 1947 b - , 9 4 - 8 SCALE ? i i i 1 4 M I L E S FIGURE II i f value of the upper 5 meters of the epilimnion for Paul lake was roughly calculated by simply halving the volume given in the published data. Likewise, the value for the percentage of depth zone (0-5 m.) is an approximation. The limnological survey on Allison lake was carried out in the summer of 1948 when the lake was high, and a l l values for this lake are computed from high water mark. Because the water level of Dry lake fluctuates with the seasons, two sets of figures are given, one set for high water and the other, for low water. The area at high water is taken from the tree-line, although the water flooded considerable areas back under the trees. This excessive flooding was due to the small size of the culvert draining the lake, which has since been enlarged so that in the future, the lake wil l not l ikely exceed a depth of 17 meters. A water level commensurate with the low water level of the f a l l of 1947 is shown in the aerial photographs. This water level was used for obtaining areas and other dimensions for the low water level expressed in Table I. Some years previous to this survey, the water level of Borgeson lake had inadvertently been raised when the road hear the outlet was improved. In the f a l l of 1948, this was rectified by deepening the culvert draining the lake, and the water level of Borgeson lake was lowered 22 inches to its original level. Two sets of values are given for the raised FIGURE III and lowered levels of the lake. Most of the limnological data was obtained at the raised level of the lake. Because future work on this lake is anticipated, however, morphometrical data for the new lowered level is tabulated in Table I also. Allison lake, at the top of the chain, is the largest, being 2.27 km. (1.4 ml.) long. A narrow constriction, about one-third of the way from the outlet, divides the lake into two natural basins. The east shore of the south basin and the west shore of both basins are rocky and steep, the inclination of the shore extending into the lake conforming to the slope of the h i l l s running down to the water's edge. The remainder of the lake shore has shallow marl shelves which become gravelly towards the shore. Beyond the shelves, the bottom inclines sharply into deep water. During dry periods, when the level of the lake drops, these shelves are exposed. The area of the shelves, judged by the 0-5 meter contour line, forms 29 per cent of the area of the lake. Borgeson lake is square in shape, although the margins of the weed beds give i t a round appearance, hence the name, Round or Square lake. The east and west corners are shallow and marshy, and when the lake was in its raised condition, the maximum length of the lake extended over these marshes in an east-west direction for a distance of 0.62 kilometers. Now that the lake is lowered, the marshes are bare, and the maximum length i , lies in a north-south direction and is 15 0.54 kilometers long. A shallow, marl ahelp at the south end of the lake in front of the outlet is s t i l l under water. Before the lake was lowered, the area of the shelves (0-5m.) was 32 per cent of the total area of the lake.' Now the area of the shelves has been reduced to 13 per cent. Along the shelfless shore line, as well as from the deeper edge of the shelves, the bottom drops off rapidly into deep water. Dry lake fluctuates seasonally, and, as a consequence, the maximum length varies between 0.80 and 1.33 kilometers. The east shore is rocky and steep, the west, gravelly and shelving. At the north and south ends of the lake, the shore is sandy and f la t . At high water, a meadow, at the extreme north end of the lake, is flooded. The area of the shelves at high water is immense, amounting to over 50 per cent of the total area of the lake. This is mostly due to the flat nature of the valley at the north end of the lake. At low water, the water recedes almost to the margins of the shelves, at which point, the bottom inclines sharply into deep water. Like Borgeson, the level of Laird lake is controlled by its outlet and the water level does not alter. Laird lake is the second largest of the series and is 1.12 lilometers long. A large, marl shelf lies across the south end of the lake. It separates a minor basin in the south-west corner from the main body of the lake. Except for this shelf and another small one about half way up the east shore of the lake, the bottom tends to drop away rapidly into deep water. The area of the shelves B O R G E S O N L A K E SCALE 0 .1 .2 MILES FIGURE V (0-5 m.) is 37 per cent of that of the lake. McCafferty is a long, narrow lake, constricted about one-third of the way north of i ts outlet into two comparatively shallow basins. At this constriction, a marl bar crosses the lake. Above the north end, practically continuous with the lake, there is a muddy marsh through which the stream from Laird lake flows. The south end of the lake is shallow, but there is a definite overfall where the lake empties into One-Mile creek. Both sides of McCafferty lake have steep slopes and the bottom falls off abruptly from the shoreline as well as from the marl bar and shelves at either end. The zone of shallow water (0-5 m.) is about 10 per cent of the area of the lake. A comparison of the morphometry of the lakes on the One-Mile creek is Important. Numerous limnologists have stressed the importance of size and shape of lakes. The size and form of lakes have direct bearing on their physical characteristics. These, in turn, influence certain chemical phenomena which, together with the physical features, limit the fauna and flora within their confines as regards both numbers and species. The author agrees with Thienmann (1927) that mean depth is one of the most significant factors to consider in lake ecology. Undoubtedly, the real significance lies in the fact that depth is the greatest stabilizing force of ALLISON L A K E - B O T T O M S A M P L E S SCALE j i i i i_ MILES i i i FIGURE VI 1 9 t e m p e r a t u r e . I t I s o b v i o u s , f o r example, t h a t s h a l l o w l a k e s t e n d t o heat up r a p i d l y and r e a c h a t e m p e r a t u r e somewhat h i g h e r t h a n s u r r o u n d i n g l a r g e l a k e s ; on t h e o t h e r hand, I t i s e q u a l l y w e l l known t h a t t h e y c o o l o f f more r a p i d l y and have a f a r g r e a t e r p r o p o r t i o n of i c e i n t h e w i n t e r . I n o t h e r words, t h e t e m p e r a t u r e s of s m a l l l a k e s a r e more extreme t h a n t h o s e of l a r g e r ones, l i m i t i n g p l a n t s and a n i m a l s i n t h e l a k e s t o those s p e c i e s w h i c h can t h r i v e I n more extreme t e m p e r a t u r e s . Mean tem p e r a t u r e i s dependent on r e l a t i v e a r e a and volume, but Rawson (1939) p o i n t s out t h a t mean de p t h I s but a f a c t o r i n t h e area-volume r e l a t i o n s h i p . Thienmann (1927) has a l s o s u g g e s t e d as t h e r e s u l t o f a mass s u r v e y o f a l a r g e number of l a k e s , c l a s s i f y i n g l a k e s w i t h depths of more th a n 18 meters as o l i g o t r o p h i c and l a k e s w i t h depths of l e s s t h a n 18 meters as e u t r o p h i c . As w i l l be no t e d i n T a b l e I , s i n c e i n each c a s e t h e mean depths a r e a l l below t h i s v a l u e , a l l t h e One-Mile l a k e s would f a l l i n t o t h i s l a t t e r c l a s s . N o t w i t h s t a n d i n g t h i s , however, t h e a u t h o r f e e l s t h a t b o d i e s of wa t e r w h i c h a r e p r o g r e s s i v e l y s m a l l e r i n s i z e d i f f e r much more markedly i n e v e r y way t h a n l a k e s w h i c h a r e of o l i g o t r o p h i c c h a r a c t e r . I n t h e f i r s t p l a c e , p r o v i d e d t h e l a k e s have t h e same c l i m a t i c c o n d i t i o n s and o t h e r f a c t o r s b e i n g e q u a l , o l i g o t r o p h i c l a k e s a r e a b l e t o ab s o r b t h e maximum number of c a l o r i e s . I t does not g r e a t l y m a t t e r i f t h e l a k e i s t w e l v e m i l e s l o n g o r f o r t y m i l e s l o n g , t h i s w i l l o c c u r . On t h e o t h e r hand, e u t r o p h i c l a k e s v a r y i n the amount o f h e a t 20: t h e y can absorb. I n g e n e r a l , t h e l e s s t h e i r mean d e p t h , the l e s s heat t h e y can absor b , and c o n s e q u e n t l y , t h e more extreme t h e i r t e m p e r a t u r e s . As w i l l be shown when d i s c u s s i n g t e m p e r a t u r e , a s m a l l d i f f e r e n c e i n mean d e p t h w i l l have a l a r g e i n f l u e n c e on te m p e r a t u r e c o n d i t i o n s . The d e p t h t o w h i c h l i g h t may p e n e t r a t e marks t h e l i m i t o f t h e t r o p h o g e n i c zone. McEwen (1929) s u g g e s t s t h a t t h e i n t e n s i t y of l i g h t f a l l s o f f as t h e r e c i p r o c a l o f a g e o m e t r i c p r o g r e s s i o n , w h i c h means t h a t f o r c l e a r w a t e r s , l i g h t p e n e t r a t i o n would o b t a i n t o t h e same depth. F o r most l a k e s , t h e t r o p h o g e n i c zone may be c o n s i d e r e d i n t h e upper 10 meters of w a t e r . F o r o l i g o t r o p h i c l a k e s , t h i s may r e p r e s e n t j u s t a s m a l l f r a c t i o n but f o r s m a l l l a k e s , as under d i s c u s s i o n , t h i s zone r e p r e s e n t s a l a r g e p r o p o r t i o n o f t h e volume of t h e l a k e s . As can.be seen i n T a b l e I , a s m a l l d i f f e r e n c e i n t h e v a l u e of the mean depth r e s u l t s i n a l a r g e change i n t h e pe r c e n t a g e volume o f t h i s t r o p h o g e n i c zone. The l a k e s on One-Mile c r e e k have a mean depth-range of from 6.0 t o 14.9 m. From t h e f o r e -g o i n g d i s c u s s i o n , we might e x p e c t t h e s e l a k e s t o show marked b l o t i c d i f f e r e n c e s . The shapes and s i z e s o f t h e s u r f a c e s of l a k e s a r e v e r y s i g n i f i c a n t . Some i d e a of a r e a may be g l e a n e d f r o m maximum l e n g t h and maximum w i d t h , o r b e t t e r s t i l l , f r o m mean w i d t h . L e n g t h of s h o r e - l i n e depends on t h e shape o f t h e l a k e . 213 R e g u l a r s h o r e - l i n e s t e n d t o g i v e l a k e s l a r g e masses of open wa t e r exposed t o wind and wave a c t i o n . T h i s has t h e d i r e c t e f f e c t of a good c i r c u l a t i o n of w a t e r d u r i n g t h e s p r i n g and f a l l t u r n o v e r s , w i t h an accompanying s u p p l y of d i s s o l v e d oxygen. F o r s m a l l l a k e s , a r e g u l a r s h o r e - l i n e would h e l p reduce t h e i r t r o p h i s m due t o an i n c r e a s e d a b s o r p t i o n of oxygen w h i l e an i r r e g u l a r s h o r e - l i n e would t e n d t o d e c r e a s e t h e v e r n a l c i r c u l a t i o n and reduce t h e oxygen absorbed. I t w i l l be n o t i c e d on t h e maps t h a t t h e s h o r e - l i n e s o f t h e l a k e s a r e a l l q u i t e r e g u l a r . Where t h e l a k e s l i e w i t h t h e v a l l e y and t h e wind has t o blow w i t h t h e v a l l e y , as i n A l l i s o n v a l l e y , t h e a r e a may not be so i m p o r t a n t t o wind a c t i o n as the maximum e f f e c t i v e l e n g t h . F o r a l l the l a k e s , the maximum e f f e c t i v e l e n g t h i s about t h e same as t h e maximum l e n g t h . W i t h t h i s i n mind, i t must be p o i n t e d out t h a t t h e l e n g t h o f Borgeson l a k e r u n n i n g w i t h t h e v a l l e y , because t h e v a l l e y makes a bend a t t h i s p o i n t , i s o n l y about 325 m. S i n c e t h e remainder o f t h e l a k e s a r e a t l e a s t 800 m. l o n g , i t f o l l o w s t h a t we might expect poor v e r n a l c i r c u l a t i o n and reduced oxygen s u p p l y i n Borgeson l a k e . S i n c e t h e shoreward w a t e r s f o r m t h e most p r o d u c t i v e zones f o r a q u a t i c o r g anisms, i t f o l l o w s t h a t t h e l e n g t h of s h o r e - l i n e w i l l d e t e r m i n e t h e abundance of l o t i c p o p u l a t i o n s t o a marked degree. A g l a n c e a t T a b l e I w i l l show t h a t t h e o r d e r o f s h o r e - l i n e development i s M c C a f f e r t y ^ A l l i s o n , Dry, Borgeson and L a i r d , w i t h M c C a f f e r t y , the b e s t . 22 A r e a a f f e c t s l a k e s i n two o t h e r ways. The g r e a t e r t h e a r e a , t h e g r e a t e r t h e number of bottom organisms, p r o v i d e d t h a t e n v i r o n m e n t a l c o n d i t i o n s a r e r i g h t and the l a r g e r t h e a r e a of trophogenism. A l s o , as R i c k e r (1937) p o i n t e d o u t , th e h y p o l i m n i o n warms by r a d i a t i o n and i t f o l l o w s t h a t a good p a r t of the e p i l i m n i o n , t o o , s i n c e t h e sun's r a y s h i t i t f i r s t . As t h e a r e a d e t e r m i n e s t h e amount of the l a k e exposed t o t h e s e r a y s , so a l s o w i l l t h e a r e a i n f l u e n c e the tem p e r a t u r e of the l a k e . The volume of l a k e s tends t o have a s t a b i l i z i n g e f f e c t on v a r i a b l e c o n d i t i o n s , s uch a s , i n f l o w i n g and o u t f l o w i n g s t _ ~ s t r e ams, h e a t , oxygen, n u t r i e n t s , e t c . Moreover, i t g i v e s an i d e a of mass. Rawson (1939) draws a t t e n t i o n t o U-shaped b a s i n s b e i n g t y p i c a l l y o l i g o t r o p h i c and V-shaped b a s i n s b e i n g t y p i c a l l y e u t r o p h i c i n n a t u r e . The even, s l o p i n g s h o r e s of the l a t t e r t y p e t e n d t o h o l d n u t r i t i v e m a t e r i a l b e t t e r , k e e p i n g i t from f a l l i n g or d r i f t i n g i n t o deep w a t e r , and thus c r e a t i n g a r i c h e r shoreward zone. However, he a l s o p o i n t s out t h a t t y p e o f b a s i n i s c l o s e l y r e l a t e d w i t h mean dep t h , because t h e s l o p e v a r i e s w i t h depth. The l a k e s on One-Mile have t y p i c a l l y U-shaped b a s i n s as i n d i c a t e d i n T a b l e I . 23 PHYSICS T r a n s p a r e n c y The w a t e r s of t h e One-Mile l a k e s a r e u s u a l l y q u i t e >- *.' . c l e a r . W h i l e a S e c c h i d i s k was not employed, the w h i t e p l a n k t o n n e t s u t i l i z e d d i s a p p e a r e d a t a d e p t h of 8 t o 9 m. f o r a l l f i v e l a k e s . D u r i n g t h e s p r i n g r u n - o f f , t h e s e a s o n a l stream, e n t e r i n g the s o u t h end o f Dry l a k e , c a r r i e s s i l t down and out i n t o the w a t e r and t h e t r a n s p a r e n c y of t h e l a k e i s reduced. Moreover, t h e t r a n s p a r e n c y o f t h e l a k e s may be d i m i n i s h e d by p l a n k t o n blooms, as on August 6, 1948, when t h e a u t h o r o b s e r v e d t h a t t h e c l e a r n e s s o f M c C a f f e r t y l a k e was n o t i c e a b l y reduced. Temperature Temperature r e a d i n g s were',taken w i t h a s t a n d a r d i . N e g r e t t i and Zambra r e v e r s i n g thermometer a t t a c h e d t o a w a t e r sampler a t t h e s t a t i o n s marked i n F i g u r e s I I t o V I , i n c l u s i v e . The t emperature s e r i e s f o r t h e l a k e s i n 1947 were t a k e n between J u l y 22 and August 27. There was a month of warm weather, p r e v i o u s t o t a k i n g t h e r e c o r d i n g s . I n t h e s p r i n g of t h e same ye a r , t h e snow m e l t e d g r a d u a l l y and the r u n - o f f was l i g h t . D u r i n g t h e p e r i o d o f s u r v e y , t h e weather was m o s t l y f i n e w i t h i n t e r m i t t e n t r a i n f a l l s . The t e m p e r a t u r e s e r i e s f o r 1948 were t a k e n soon a f t e r i c e l e f t t h e l a k e s i n t h e s p r i n g and c a r r i e d t h r o u g h u n t i l f a l l . The s p r i n g r u n - o f f t h a t y e a r was e x c e p t i o n a l l y l a r g e and t h e l a k e s and streams f i l l e d T E M P E R A T U R E S E R I E S FIGURE Vll 25 rapidly. The weather was fine during the early summer and turned cold and wet in late July and August. The four lower lakes of the.series were consequently colder in 1948 than in 1947. No temperature records were taken on Allison lake in 1947. The lake was prohably cooler in 1948, due both to flood conditions and a cool August. Figure IX shows certain temperature series in Allison lake. Because ice remained around the margins of the Summit lakes, located three miles north of Allison lake, until May 8, 1948, i t was probable that Allison lake was s t i l l 4°C. near the end of Apri l . On May 10, when temperatures were f i rs t taken, surface temperatures were 7 ° . Temperature gradients had already set in and possibly only partial circulation was taking place. By June 1, the surface waters had warmed to 1 8 . 6 ° . On July 17, the temperature gradient was almost constant, rising from 7*9° to 19 .4° in the upper 12 m. strata. Temperatures were uniform in the epillmnion by Sept. 5 because of decrease in surface temperatures. Temperature conditions for the remaining four lakes are shown in Figures VII'and VIII for the summers of 1947 and 1948, respectively. On August 8, 1947, Borgeson lake reached a maximum surface temperature of 18 .5° and had developed a temporary stratification which was lost by August 27. In 1948, the highest surface temperature was slightly lower than in 1947 and definite stratification was lacking. T E M P E R A T U R E S E R I E S C O N T R O L M C C A F F E R T Y L A K E TEMPERATURE — DEGREES CENT-3 10 15 2 0 V I / * ) L A K E S - 1 9 4 8 L A I R D L A K E TEMPERATURE —DEGREES CENT. 0 5 10 15 20 T T E X P E R I M E N T A L D R Y L A K E TEMPERATURE— DEGREES CENT. L A K E S - 1 9 4 8 B O R G E S O N L A K E . TEMPERATURE— DEGREES CENT. 2 2 2 1 I I £ UJ a to o OJ 20 FIGURE VIII 27 The c o n t r a s t between c o n d i t i o n s i n Dry l a k e i n 1947 and 1948 was a l s o marked. I n 1947, t h e h i g h e s t s u r f a c e t e m p e r a t u r e r e c o r d e d was 18 .7° and i n 1948, 17«8°. As shown i n F i g u r e V I I f o r August, 1947, s t r a t i f i c a t i o n e x i s t e d w h i c h i s u n u s u a l f o r a l a k e 13 m. deep. The e p i l i m n i o n was s h a l l o w i n t h e e a r l y p a r t of t h e month b u t deepened t o 5 m. by August 26. The t h e r m o c l i n e was v e r y s h a r p , d r o p p i n g 6° I n about 3 m. The temperature g r a d i e n t i n t h e h y p o l i m n i o n was moderate. U n l i k e Borgeson l a k e , l e s s d i f f e r e n c e s i n te m p e r a t u r e e x i s t e d i n Dry l a k e i n 1948. As I l l u s t r a t e d i n F i g u r e V I I I , no s t r a t i f i c a t i o n was p r e s e n t b e f o r e May 10 or a f t e r O c t o b e r 9 f o r t h i s year. D u r i n g t h e summer, t h e r e were m o d e r a t e l y d e f i n e d t e m p e r a t u r e s t r a t a . As seen from T a b l e V I , th e e p i l i m n i o n was about t h e same depth. The t h e r m o c l i n e , w h i l e marked, was somewhat l e s s pronounced t h a n t h a t of t h e p r e c e d i n g y e a r . The o n l y prominent d i f f e r e n c e , between t h e temp e r a t u r e c u r v e s f o r 1947 and 1948, was t h e d e p t h of t h e h y p o l i m n i o n . I t appears t h a t t h i s d i f f e r e n c e i s r e l a t e d t o the d e p t h of t h e l a k e f o r t h e s e p e r i o d s . I n 1947, t h e h i g h e s t s u r f a c e t e m p e r a t u r e f o r L a i r d l a k e was 1 9 . 1 ° , f o r 1948, 1 8 . 2 ° . F i g u r e s V I I and V I I I i n d i c a t e t h a t t h e r m a l s t r a t i f i c a t i o n was not pronounced i n e i t h e r y e a r . L i k e Borgeson and D r y l a k e s , no marked tem p e r a t u r e g r a d i e n t was p r e s e n t b e f o r e May 9, 1948, o r l a t e r t h a n October 9 of t h e same yea r . F i g u r e V I I I shows t h a t c i r c u l a t i o n o f t h e upper 10 m. s t r a t a was p o s s i b l e a t t h i s l a t t e r d a t e . T E M P E R A T U R E S E R I E S FIGURE IX 29? The maximum s u r f a c e t e m p e r a t u r e s of M c C a f f e r t y l a k e , the l a s t of the s e r i e s , v a r i e d a t l e a s t 2.5° f o r t h e two y e a r s t h e y were survey e d . On J u l y 21, 1947, t h e h i g h e s t s u r f a c e t e m p e r a t u r e was 19°; on J u l y 25, 1948, 16.5°• The bottom t e m p e r a t u r e s o f M c C a f f e r t y l a k e were t h e h i g h e s t f o r the s e r i e s . Thermal s t r a t i f i c a t i o n , i n M c C a f f e r t y l a k e , i s v e r y s i m i l a r t o t h a t shown by Juday and B l r g e (1932) f o r Diamond l a k e , n o r t h e a s t e r n W i s c o n s i n , w h i c h i s about 1 m. deeper and w h i c h has a c o n s i d e r a b l y h i g h e r mean te m p e r a t u r e . Mean t e m p e r a t u r e s Mean t e m p e r a t u r e s were c a l c u l a t e d by methods o u t l i n e d by B i r g e and Juday (1914), i . e . , summing t h e p r o d u c t s o f t h e mean temp e r a t u r e and t h e p e r c e n t a g e volume f o r each s t r a t u m . Mean t e m p e r a t u r e s f o r t h e One-Mile l a k e s a r e shown i n T a b l e X and a r e p l o t t e d on F i g u r e X. The s h o r t l i n e s r e p r e s e n t c o n d i t i o n s f o u n d i n t h e summer of 1947. The l o n g l i n e s show the s e a s o n a l t r e n d o f mean t e m p e r a t u r e s from s p r i n g u n t i l f a l l f o r t h e y e a r 1948. From i n f o r m a t i o n r e c e i v e d r e g a r d i n g i c e c o n d i t i o n s f o r t h a t y e a r , t h e d a t e s when t h e s u r f a c e water was 4° were e s t i m a t e d as May 1 and November 13• F i g u r e X on mean t e m p e r a t u r e s i s i n d i c a t i v e of t h e g r o s s h e a t o b t a i n e d by t h e l a k e s between t h e p e r i o d s s p e c i f i e d . Rawson (1936) showed t h e average t r e n d of mean temp e r a t u r e s f o r Waskeslu l a k e , Saskatchewan. The mean M E A N L A K E T E M P E R A T U R E S " I 9 4 7 & I 9 4 8 temperature curve of Waskesiu and the One-Mile lakes was characterized by an abrupt rise in temperature, once the Ice had left the lakes. This is due to the delaying action of melting ice absorbing heat from the water, so that, by the time the ice is melted, the weather has become much warmer, enabling the water to heat at a more rapid rate. In the autumn, the mean temperature of the water tapers off more gradually. The One-Mile lakesy/are not completely frozen over as late as December 4, 1948. There is an equithermal period from approximately the middle of July to late August, when the mean temperature of any one lake varies l i t t l e . This is in keeping with the mean temperatures of the Finger lakes. For lakes of the size of the One-Mile group, i t would be expected that fluctuations in temperature would be greater than for larger lakes, since they would be more susceptible to changing atmospheric conditions. The cooler summer was partly responsible for the marked differences of temperature between the equithermal periods of the lakes for the two years M'Gonigle (1938) shows that the pattern of seasonal mean temperatures follows a "sine curve." In Figure IV, i t appears that in 1947, the equithermal plateau must have been fair ly short. This also would agree with mean temperature conditions found in other lakes, such as the Finger lakes of New York (Birgeand Juday 1914) and Waskesiu lake in Saskatchewan (Rawson 1936). It was observed also that Laird and Dry lakes were the coldest and that they had approximately the same mean temperatures, that Borgeson was 32: t h e n e x t warmest, and t h a t M c C a f f e r t y l a k e had by f a r t h e h i g h e s t mean t e m p e r a t u r e s . From o b s e r v a t i o n s made i n 194-7, t h e r e was p r a c t i c a l l y no seepage f r o m A l l i s o n l a k e when t h e water l e v e l was low. As t h e l e v e l o f t h e l a k e s u b s i d e d , t h e seepage from D r y l a k e was c o n s i d e r a b l y reduced, as was i n d i c a t e d by t h e s l o w e r r a t e a t w h i c h the l a k e dropped, and a l s o , by t h e d e c r e a s e d volume of- w a t e r l e a v i n g L a i r d l a k e . I t appeared l i k e l y , from t h e s e i n d i c a t i o n s , t h a t i t was t h e upper w a t e r s t h a t found t h e i r way out of t h e l a k e s . T h i s would not a f f e c t t h e t e m p e r a t u r e of A l l i s o n l a k e v e r y much, on account of i t s c o m p a r a t i v e l y l a r g e a r e a and t h e f a c t t h a t t h e w a t e r l e v e l dropped s l o w l y . Dry l a k e would t e n d t o be c o l d e r , however, s i n c e i t d r a i n e d away much f a s t e r , and, h a v i n g a r e l a t i v e l y s m a l l a r e a , would l o s e a l a r g e p e r c e n t a g e o f i t s e p i l l m n i o n d a i l y . I n 1947, due t o t h e low l e v e l o f A l l i s o n l a k e , l i t t l e seepage e n t e r e d Borgeson l a k e and, as a consequence, t h e r e was no c o o l i n g e f f e c t due t o ground w a t e r . Thus, t h e mean te m p e r a t u r e c o n d i t i o n s i n Borgeson were h i g h e r i n 1947 t h a n i n 1948. L a i r d l a k e would o b t a i n c o l d seepage from Dry l a k e w h i l e t h e l a k e l e v e l was f a l l i n g , and, as a r e s u l t , I t would a l s o t e n d t o be c o l d . As has been s t a t e d , M c C a f f e r t y l a k e , not b e i n g f e d by underground water and, i n a d d i t i o n , b e i n g s h a l l o w e r t h a n t h e h i g h e r l a k e s , had a c o n s i d e r a b l y h i g h e r mean temperature t h a n any of t h e o t h e r l a k e s . As shown i n F i g u r e X, t h e mean temp e r a t u r e i n 1948 f o r A l l i s o n , Borgeson, Dry and L a i r d l a k e s were v e r y c l o s e l y a l l i e d t h r o u g h o u t t h e m i d d l e f i v e summer months. Only M c C a f f e r t y l a k e v a r i e d from t h e above a l l i a n c e and t h e v a r i a t i o n was v e r y marked. Moreover, t h e r e was an e q u i -t h e r m a l p e r i o d i n t h e s e f o u r l a k e s f r o m June 1 t o October 10. T h i s l o n g t e m p e r a t u r e p l a t e a u was not found i n M c C a f f e r t y l a k e , Waskesiu l a k e , n or i n t h e l i m n o l o g i c a l s t u d y o f t h e F i n g e r l a k e s of New York, such b e i n g c o n f i n e d t o a much s h o r t e r mid-summer p e r i o d . As shown by t h e l o n g e q u i t h e r m a l p l a t e a u I n F i g u r e X, f a i l u r e o f t h e mean te m p e r a t u r e t o r i s e a f t e r June 1, 1948, was a t t r i b u t e d t o seepage. Moreover, t h e mean te m p e r a t u r e s of t h e e q u i t h e r m a l p e r i o d s were d i s t i n c t l y l o w e r i n 1948 t h a n t h e y were i n 1947. I f i t were assumed t h a t t h e te m p e r a t u r e of t h e ground w a t e r was low, due t o i t s passage underground, t h e n , i n 1948, ground water would account f o r t h e r e m a r k a b l y u n i f o r m t h e r m a l c o n d i t i o n s w h i c h were found between t h e s e f o u r upper l a k e s . Because underground water c o n t i n u e s t o be p r e s e n t as l o n g as t h e w a t e r l e v e l s o f A l l i s o n and Dry l a k e s a r e h i g h , t h i s seepage t h e o r y would a l s o a c c o u n t f o r t h e s u s t a i n e d e q u i -t h e r m a l p e r i o d i n t h e s e f o u r l a k e s f o r t h i s season. The f a c t t h a t a r e l a t i v e l y heavy volume o f s u r f a c e water f l o w s c o n t i n u o u s l y f r o m L a i r d l a k e t o M c C a f f e r t y l a k e , i n d i c a t e s t h a t seepage from L a i r d l a k e i s n e g l i g i b l e . As a consequence, t h e t e m p e r a t u r e of M c C a f f e r t y l a k e would not be a f f e c t e d by c o l d seepage l i k e t he o t h e r l a k e s . , Summer heat budgets The t h r e e columns f o l l o w i n g , a r r a n g e d i n sequence o f summer heat Income w i t h t h e l a r g e s t a t t h e t o p , w i l l show how e a s i l y t h e heat budgets of s m a l l l a k e s may be d i s t u r b e d even under t h e same c l i m a t i c c o n d i t i o n s : T h e o r e t i c a l o r d e r A l l i s o n L a i r d B o r g eson Dry M c C a f f e r t y O rder 1 9 4 7 No r e c o r d s B o r g e s o n L a i r d M c C a f f e r t y Dry Order 1 9 4 8 A l l i s o n L a i r d B o r g eson M c C a f f e r t y D r y The t h e o r e t i c a l o r d e r of summer heat income i s based p r i m a r i l y on mean depths. D e v i a t i o n f r o m t h e t h e o r e t i c a l o r d e r o f from h i g h t o low v a l u e s f o r summer he a t Incomes can be e a s i l y e x p l a i n e d by t h e seepage t h e o r y . I n the summer of 1 9 4 7 , B o r g e s o n l a k e i s seen t o have a h i g h e r v a l u e t h a n L a i r d l a k e , even though i t s mean d e p t h and i t s maximum e f f e c t i v e l e n g t h i s l e s s t h a n L a i r d l a k e . As e x p l a i n e d under "Mean te m p e r a t u r e , " t h i s c o n d i t i o n was due t o c o l d seepage e n t e r i n g L a i r d l a k e , c o n s t a n t l y l o w e r i n g i t s summer heat income. I n 1 9 4 8 , due t o c o l d seepage e n t e r i n g a l l the l a k e s above M c C a f f e r t y l a k e , t h i s c o n d i t i o n was e q u a l i z e d and Borgeson l a k e h e l d t o t h e t h e o r e t i c a l o r d e r . I n b o t h y e a r s , D r y l a k e had a s m a l l e r h e a t Income t h a n M c C a f f e r t y l a k e . Through seepage, Dry l a k e l o s t I t s warm s u r f a c e w a t e r and, i n r e t u r n , r e c e i v e d a c e r t a i n amount of c o l d ground w a t e r . I n 1 9 4 7 , t h e amount of seepage i n t o t h e l a k e was v e r y s m a l l and, a l t h o u g h 3 5 heat was lost due to warm water leaving the lake, the summer heat income almost equalled that of McCafferty lake. In 1 9 4 8 , the large influx of cold seepage entering the lake aided the surface run-off in reducing the temperature well below that of McCafferty lake. McCafferty lake, on the other hand, was fed continuously by a surface stream from Laird lake that was considerably warmer than the subterranean water entering the other lakes and, In consequence, McCafferty lake had a higher heat income than Dry lake for both seasons. Although Paul lake is considered by Rawson ( 1 9 3 4 ) to be an oligotrophic lake of the sub-Alpine type, yet i t was useful for making comparisons, since i t lies at approximately the same altitude and has the same type of climate and fauna. One-Mile lakes are characterized by moderately hot days and cool nights, which are conducive to cooling of the surface waters at night, reducing the amount of heat the lakes can absorb. The hi l l s enclosing the lakes shorten the hours of sunlight, so that less heat Is obtained by the water. This latter factor affects Paul lake less than the One-Mile lakes, because i t runs In an east-west direction and obtains the maximum amount of light from the rising and setting sun. The One-Mile lakes are affected according to their width which, in a general way, represents an index to the breadth of the valley at their respective locations. Borgeson lake, however, is so situated at a bend in the valley that, regardless of width, i t isj less confined by precipitous h i l l s than the other 36 lakes In the series, and receives more sunlight. For comparative purposes, the summer heat income, along with the data, is given in Table IX, covering the five lakes under discussion as well as Paul lake. The summer heat income of Paul lake for 1931 was 1 8 , 5 0 0 gm. cal. / cmv2 This value is much higher than that of any of the One-Mile lakes and was explained by a preceding discussion under the heading, "Morphometry," in which It was concluded that the heat budget of a lake was primarily dependent on its mean depth and area in relation to its maximum effective length. Temperature, alone, cannot be considered as a limiting factor in the productivity of lakes. Lacky (1938) states that for Protozoa, found in nature, temperature, light and food only limit the quantity of these animals. Certainly, temperature and light cannot be considered Independent of the chemical conditions found in lakes which are fundamental for the sustenance of l i f e . As listed later, a wide variety of plants and animals have been able to perpetuate under the existing temperatures found in these lakes, and i t Is not likely that thermal conditions alone are the limiting factors for l i fe in temperate lakes, such as the One-Mile lakes. Heilbrunn (1937) has tabulated a variety of species from various sources under the heading "Heat Death Temperature." This l i s t shows that the lethal temperatures for most organisms are far above those temperatures found in the One-Mlle lakes. Hart (1947) has shown that lethal temperatures f o r v a r i o u s f i s h from O n t a r i o , one s p e c i e s of w h i c h i s r e p r e s e n t e d i n the One-Mile l a k e s , a r e w e l l above t h e e x i s t i n g t e m p e r a t u r e s i n the l a k e s under d i s c u s s i o n . C l a s s i f i c a t i o n Numerous a r t i c l e s have been w r i t t e n on t h e c l a s s i f i c a t i o n o f l a k e s , most of w h i c h p o i n t t o t h e f r u i t l e s s -ness o f t r y i n g t o c l a s s i f y l a k e s on the b a s i s o f a s o l e c r i t e r i o n . As Welch (1940) has p o i n t e d o u t , the W h i p p l e m o d i f i c a t i o n o f the F o r e l system, based s o l e l y on temperatures, i s one o f t h e b e s t f o r t h i s purpose i f a s i n g l e c r i t e r i o n i s t o be employed. Because s u r f a c e t e m p e r a t u r e s v a r y above and below 4°C., and f o r t h e f o u r u pper l a k e s bottom t e m p e r a t u r e s a r e n o t f a r f r o m 4°, t h e y may be c l a s s i f i e d as temperate l a k e s of t h e second o r d e r . Bottom t e m p e r a t u r e s of M c C a f f e r t y l a k e a r e q u i t e removed from 4°, but t h e r m a l s t r a t i f i c a t i o n s t i l l e x i s t s , so t h a t complete c i r c u l a t i o n i s i m p o s s i b l e . C o n s e q u e n t l y , M c C a f f e r t y l a k e forms a b o r d e r - l i n e c a s e between the second and t h i r d o r d e r of temperate l a k e s . 38 CHEMISTRY The One-Mile lakes are typically Chara lakes, some of which have extensive marl beds along the shore-line. Allison lake, at the head of this series of lakes, has large deposits of marl along its east shore-line and, a very deep marl bed at the south end of the lake. This marl bed is of such exceptional quality that i t is now being dredged, dried and sold as a commercial fer t i l izer for the neutralization of acid soils . The mud in the deeper waters of Allison lake was chocolate in colour. Borgeson lake, the next In the series, has a narrow' marl deposit along its north-east shore. The bottom mud, flooring the greater part of the lake, was brown in colour and has a distinctly fetid odour, characteristic of hydrogen sulphide gas. Dry lake, the centre lake in the series, has no marked marl beds. The north and south ends of the lake are composed largely of sandy mud, which appears to have been deposited largely by the creeks flowing into the lake. The bottom mud is quite black in colour, the reason for which has not been ascertained. Laird lake, below Dry lake, has a fairly large t r i -angular shelf of marl, Jutting out into the lake from the middle of its eastern shore. A much larger marl shelf is located across the south end of the lake. The bottom mud of 3 9 Laird lake i s of a dark-brown colour i n the deeper water. McCafferty lake, at the lower end of this series of lakes, has marl deposits across the neck which separates the north and south d i v i s i o n and also has a small deposit at i t s o u t l e t . The mud of the lake bottom i s dark-brown In colour, but a large percentage of i t contains coarser p a r t i c l e s of undecomposed organic material i n the nature of twigs, seed husks, s h e l l s and other debris. Oxygen Oxygen samples, along with temperatures, were taken with a standard water sampler which was used f o r obtaining water samples at various depths. Temperature records were taken at the same time as the samples. The samples for oxygen determination were taken at the same stations mentioned under the heading "Temperatures." The Winkler method f o r oxygen determinations was used i n both years. As only 1 0 0 ml.aliquots were used, no corrections were made f o r the loss due to displacement by the reagents. Several times each season, the sodium thi o s u l f a t e solution was standardized against potassium dichromate. The v e r t i c a l d i s t r i b u t i o n s of dissolved oxygen i n the One-Mile lakes are i n Tables XI to X V i n c l u s i v e . The percent-age saturation values were determined by using a nomogram (Rawson ' 4 4 ) f o r the ca l c u l a t i o n of oxygen saturation values and t h e i r correction f o r a l t i t u d e . The values f o r the quantity of oxygen required f o r saturation at the temperatures S E L E C T E D O X Y G E N G R A D I E N T S M c C A F F E R T Y L A K E L A I R D L A K E 16 AUG 1947- 17 AUG 1948 IAU61947 4 SEPT 1948 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 PPM. P P M . RRM. P.RM. D R Y L A K E B O R G E S O N L A K E 2 6 AUG 1947 3 SEPT. 1948 27 AUG 1947 4 SEPT. 1948 0 2 4 6 8 10 PR M. 2 4 6 8 10 P P M . 2 4 6 8 10 P. RM. 2 4 6 P. P. M. 8 10 FIGURE XI 0 2=dissolved oxygen 0^- oxygen required for saturation 41 indicated were obtained from standard tables and adjusted for altitude. A selected altitude of 2,630 feet (800 m.) was used for a l l five lakes in the above calculations. The vertical distribution of dissolved oxygen and the quantity of oxygen required for saturation are shown in Figures XI and XII." In 1947, surface samples were taken 15 m. below the surface. In 1948, they were taken Just beneath the surface. Bottom samples were taken at the depths recorded. During late July and early August, 1947, dissolved oxygen in McCafferty lake was higher at the bottom than at the surface. The surface oxygen rose from 8.26 mgm./l. on July 25 to 8.86 mgm./l. by August 16. In contrast, the bottom oxygen dropped from 9.75 mgm./l. on July 25 to 7.87 mgm./l. by August 16. However, the difference between the surface and bottom saturation values are slight and may be attributed to the equithermal conditions found in the lake that summer. From late July to early September/, 1948, surface oxygen ranged from 7.92 mgm./I..to 8.30 mgm./l.. The lowest saturation value occurred on August 17. Bottom values for dissolved oxygen dropped from 5*77 mgm./l:; to I.30 mgm./l. on August 17, rising to 2.42 mgm./l. by September 3. In contrast with 1947, the surface values for dissolved oxygen are slightly lower for 1948. The bottom values in 1948 dropped to a low of 12% saturation, whereas, in 1947, the bottom saturation values for oxygen showed a slight increase over surface values, being slightly over-saturated on July 25* S E L E C T E D O X Y G E N G R A D I E N T S FIGURE XII Qg, ^ dissolved oxygen. C>2 s oxygen r e q u i r e d f o r s a t u r a t i o n 43 Flgure,._XI. shows the periods when dissolved oxygen, during the summer stagnation period, was at its lowest. A marked difference between the two years is apparent. In 1947, when there was no marked thermocline, the quantity of dissolved oxygen was almost constant and nearly saturated from the surface to the bottom of the lake. In 1948, .con-ditions were entirely different when a more pronounced ther-mocline was formed, and the amount of dissolved oxygen de-creased with the f a l l of temperature at the bottom of the lake. On the four dates examined in 1947, surface oxygen ranged from 7.90 to 8.60 mgm./l., whilst, in 1948, i t fluctuated between 9.10 and 7.48 mgm./l. In both years, the surface oxygen varied irregularly between the dates sampled, being lowest on August 1, 1947 and on August 8, 1948. On August 1, 1947," the bottom oxygen dropped as low as 2 . 6 3 mgm. / l . On September 4 of the same year, however, the 18 meter sample indicated that the quantity of dissolved oxygen might have been even lower at the same depth to that taken on August 8. Figure 1X1 shows the vertical distribution of dissolved oxygen for the dates of greatest oxygen depletion at the bottom of the lakes for both years. On August 1, 1947, the distribution of oxygen was characterized by being 20 per cent over-saturated in the thermocline and upper hypolimnion. Riley (1939) found an increase in the oxygen content of the 44 hypolimnion of Linsley lake, Connecticut, and explained t h i s increase i n the hypollmnetic oxygen to pseudo-ollgotrophy. The explanation of this oxygen condition i n L a i r d lake might be analogous to that of Linsley lake. In 1948, thi s con-d i t i o n did not occur, and on September 4, the v e r t i c a l d i s t r i b u t i o n of oxygen was almost uniform down to a depth of 15 meters. In both years, the supply of oxygen f e l l away rapidly from about the 15-meter mark to the bottom. Dissolved oxygen samples were taken from July 26 to August 26, 1947 and, from July 25 to September 3, 1948. In 1947, the surface values ranged from a low of 8.77 on August 4 to a high of 9.54 on August 26, whilst, i n 1948, the sur-face oxygen ranged from 8.18 mgm./l. on August 7 to 9.23 mgm./l. on September 3. In 1947, bottom values f o r the whole period were extremely low, the lowest value being .094 mgm./l. and occurring on August 26. In 1948, dissolved oxygen at the bottom varied between 2.69.mgm./l. on July 25 and .36 mgm./l. on September 3» The v e r t i c a l d i s t r i b u t i o n of d i s s o l v -ed oxygen i s given i n FlgureX I f o r August 26, 1947 and f o r September 3, 1948. As shown i n Figures VII And Vin temperature curves f o r 1947 and 1948 were quite d i f f e r e n t , and the differences i n oxygen d i s t r i b u t e d were equally marked. In 1947, there was a good supply of oxygen i n the epilimnion; being s l i g h t l y over-saturated on a l l the periods investigated. Oxygen f e l l o f f abruptly i n the thermocline and was very d e f i c i e n t i n the hypolimnion. On September 3» 1948, there was almost a straight line relationship between dissolved oxygen and depth. On this date only, was the water found to be slightly over-saturated at the surface. On August 4, 1947, a sample of spring water, entering the north end of "'Dry. lake, was taken and found to contain 6.19 mgm./l], of dissolved oxygen. In gorgeson lake, dissolved oxygen samples were ob-tained between July 27 and August 27, 1947, and between July 26 and September 4, 1948. In 1947, the lowest surface sample was 8.08 mgm./l'. on August 8 and the highest surface sample was 9.43 mgm./l. on August 27. The following year, the high-est surface sample was 8.88 mgm./l. on August 7 and the low-est was 8.8 mgm./l.-on September 4. For both years, on a l l dates samples were taken, the bottom depths were devoid of oxygen. In 1947, however, there was a good supply of oxygen at the 11.5 m. mark, whilst, in 1948, the 12 m. mark was about 50 per cent less saturated. The vertical distribution of dissolved oxygen is shown in FigureXlof Borgeson lake for 1947 and 1948. As shown in the graph on August 27, 1947, the upper strata of the lake were over-saturated, whilst, on September 4, 1948, there was a considerable depletion of oxygen even in the upper strata. .'*> Jewel (1927) points out that ground water is usually depleted'"!of oxygen, due to the absorption of oxygen by minerals in the earth, and that lakes that have no offensive, 46 fetid, or "stagnant" smell in waters depleted by oxygen, may lack oxygen due to the inflow of ground water. Since Borgeson lake has no oxygen supply at the bottom, and also has a distinctly fetid odour, i t may be assumed that either ground water enters the lake at a higher temperature than the bottom waters of the lake, or that l i t t l e ground water enters the lake at a l l . Oxygen conditions for Allison lake were taken between July 27 and August 26, 1948. The surface oxygen f e l l away from a high of 9.20 mgm./l. on July 27 to a low of 8.55 mgm./l on August 26. Below the 20 m. depth, oxygen was reduced to about 10;per cent of the saturation value. At 33:m., there was no trace of oxygen. Figure Xllsftaows the vertical distribution of dissolved oxygen on August 26, 1948, for Allison lake. This shows that the upper 10~m. strata was super-saturated at this time. From the 10r-20"m. mark, the dissolved oxygen f e l l away at an even rate to about 10 per cent of the saturation value. From the 20 m. depth down, the oxygen content grew progress-ively less. As indicated above, there is.not a great deal of difference in the abundance of surface oxygen between any of the lakes for either year. Dissolved oxygeusia almost absent at the bottom of Dry lake and entirely absent from the bottom waters of Borgeson and Allison lakes. For both years, Laird lake had a fairly consistent supply of bottom 47 Oxygen which was in sharp contrast with results found in Dry, Borgeson and Allison lakes. McCafferty lake showed a wide variation in the quantity of bottom oxygen found in the two different years. In 1947, this, lake had a better supply of bottom oxygen than any other lake in the series. In 1948, the abundance of bottom oxygen decreased 6.5 mgm./l., reduc-ing i t to a quantity below that which was found in Laird lake. In general, there was a greater abundance of dissolved oxygen in the lakes in 1947, than in 1948. Dry lake, however, had slightly less dissolved oxygen in the lake in 1947, than in 1948. Several reason might be advanced concerning the annual variations in the oxygen supply of the One-Mile lakes,excluding Allison lake. A sudden warming of the atmosphere, causing floods, as occurred in 1948, would raise lake temperatures quickly, making for a rapid stratification and a consequent shortening of the vernal circulation period. Thus, the lake would have less chance of absorbing oxygen from the atmosphere. In 1948, Dry lake contained more oxygen than in the preceding year, which was possibly due to the stream entering the south end of the lake. During the spring run-off, i t was a raging torrent, which must have become well saturated with oxygen in its tumbling journey down the Mountain-aide. On entering the lake, its temperature was 5.7 degrees centigrade, which enabled its oxygenated water to sink down to the depths of the lake. Since this stream 48 was the i n i t i a l cause of the lake rising 16-177meters a day, finally overflowing the lake, i t is quite possible that this stream gave Dry lake a better oxygen supply in 1948, than in the preceding year. Another reason for changing oxygen conditions in the lakes might be due to photosynthesis of phytoplankton, but i t would be hard to show why this should affect the lakes more one year than another. 2 Welsh (1935) has listed numerous animals from various sources, which are known to occur in the profundal oxygenless regions of American lakes. He also mentions that i t is reasonably well-established that certain fishes, including trout, have a higher dissolved oxygen minimum (about 2 to 3*5 mgm./l.) than many other fishes. Surface oxygen a Paul lake (Rawson *31) ranged from 6.0 mgm./l. on June 27", 1931 to 15.0 mgm./l. on July 9, 1941. At the 15 meter mark, oxygen ranged between 6.0 mgm./l. and 8.8 rngmr./l. from June 27 to September 29, 1931. On comparing these data with those of the One-Mile lakes, i t appears likely that oxygen is not a direct limiting factor for trout culture. Hydrogen ion concentration Details of the hydrogen ion concentration are given in Table XVI for the One-Mile lakes. They were ascertained with a standard Taylor pH comparator, using Cresol red as colour indicator. The table shows surface readings taken for early September, 1947, and vertical readings for early 49 September, 1948, except for Allison lake which had vertical readings taken in both July and August also. The readings in 1947 were a l l taken from the water's edge; for McCafferty lake, they were taken near the outlet, for Laird lake, near the northeast corner, for Borgeson lake about the: middle of the south-east shoreline and for Allison, at the north end of the lake. The vertical series of observations were a l l taken at the same stations as those for temperatures. The greatest annual variation in surface hydrogen ion concentration was found for Borgeson and Allison lakes. The former lake had a pH range from 8.1 in 1947 to 7.8 in 1948, while the latter had a pH range from 8 . 3 in 1947 to 7.7 in 1948. The remainder of the lakes only fluctuated through a pH range of .1. The vertical hydrogen ion concentration was found to decrease with increasing depth. The greatest variation was found to occur in Allison lake on August 9, 1948, when the surface pH was 8.3 and the pH at the 33 meter level was 7.3. The vertical variation for the remainder of the lakes was .2 for Borgeson and .1 for the other three lakes. Rawson (1934) stated that the pH of the surface water of Paul lake ranges from 3.0 to 8.2. He associates this alkalinity with the extensive marl beds and lime-encrustBd Chara found in Paul lake. Lacky (1938) stated that a high range of hydrogen: ion concentration and chemical concentration in natural 50 waters is shown to be tolerated by a large number of species of Protozoa. Wiebe, etc., (1934) found for Salmo shaata Jordan (the rainbow trout) that individuals of this species of two small size groups, showed a marked tolerance to d i f -ferences in hydrogen ion concentrations. From pH 5.2 to pH 8.5, the fish showed very l i t t l e difference in their lethal oxygen requirements. Several other species of fish were studied also, and using a minimum of oxygen, the pH range suitable for a l l of these fish was between 7~.2 to 8.5. Since the hydrogen ion concentration fluctuates very l i t t l e annually or vertically, changes in the alkalinity of the waters could only have a very minor effect on the fauna of the One-Mile lakes. Silicate, Phosphate and Iron Using standard Taylor comparators, the concentrations of these chemicals were determined on September 15, 1947; for the lower four of the One-Mile lakes. The total iron registered zero on the comparator and the phosphates showed but a trace for a l l four lakes. The silicate concen-trations were found as follows: 0 McCafferty lake 10 p.p.m. Laird lake • 9 p.p.m. Dry lake 6-7 p.p.m. Borgeson lake 9 p.p.m. 51 FLORA AND FAUNA Qualitative analysis of the flora and fauna of the One-Mile lakes are shown in Tables XVII and XVIII. Quantitative comparisons are reserved for discussion under the heading RESULTS . The more abundant species of phytoplankton were Synedra  Eraglllarla and Asterlonella, the less abundant, Cyclotella, Tabellaria and Diatoma• A bloom of Anabaena occurred in Dry lake in the f a l l of 1947, but otherwise, i t was present only in small quantities. Gomphosphaeria was present in large quantities in Dry lake during the summer of 1948. Around the First of June, 1948, a bloom of Clathrocystls occurred in Allison lake. On August 6, 1948, the water of McCafferty lake had a distinctly milky appearance. A subsequent analysis of the plankton collection taken at that date showed that about 40$ of i t was composed of Microcystis. The species of the larger aquatic plants were found to be most numerous in McCafferty lake at the lower end of the series. Due to the seasonal change of the water levels of Dry and Allison lakes, the dominant species of higher aquatic plants peculiar to the One-Mile lakes fal ls into-two distinct groups. Dry and Allison lakes were characterized by the Smart Weed, Polygonum, which occupies large areas of the shelves at both the north and south end of Dry lake and and the north and east shores of Allison lake. On the other hand, McCafferty, Laird and Borgeson lakes were dominated by the emergent "bulrush, Sclrpus ,and the submerged stonewort, Chara. The Invertebrate population of the One-Mile lakes was varied. Species of Rotifera were numerous and certain species were very abundant. The Cladocera populations showed a large number of pond as well as limnetic types. Aquatic insects were also well represented. Nine species formed the fish fauna of the One-Mile lakes. Except for the Speckled Char, Salvelinus fontlnalls (Mitchill) which was Introduced, the species of fish found in the One-Mile lakes were common to the lakes and tributaries of the Columbia River System. The Torrent Sculpln, Cottus  rotheus (Rosa Smith) was reported by Carl and Clemens (1948) to be present in McCafferty lake as well as in the Kooteney river. The author has also found i t in the Similkameen..river, below Princeton, B.C. The remaining seven species were reported also in Okanagan lake (Clemens, Rawson and McHugh, 1939). Table XIX.shows the stocking records for the One-Mile lakes up to the Year 1947. These were obtained from the Annual Report on Fish Culture of the Department of Fisheries as well as from the Report of the Provincial Game Commission. 53 E X P E R I M E N T A L P L A N ROTENONE AND FISHTOX Rotenone i s d e r i v e d f rom d e r r i s , cube and tlmbo r o o t s , and has the c h e m i c a l f o r m u l a ^23^22^6' Q^er t o x i c s u b s t a n c e s l e s s p o t e n t t h a n b u t a s s o c i a t e d w i t h r o t e n o n e a r e d e g u e l i n , t e p h r o s i n and t o x i c a r o l . I n h i s i n t r o d u c t i o n , L e o n a r d (1938) r e v i e w s some of t h e l i t e r a t u r e r e g a r d i n g t h e h i s t o r y of ro t e n o n e and i t s e f f e c t s on f i s h . N a t i v e s of Sumatra and Sarawack have u s e d d e r r i s r o o t f o r s t u n n i n g and k i l l i n g f i s h . C o m m e r c i a l l y , r o t e n o n e has been used e x t e n s i v e l y as a b a s i s f o r I n s e c t i c i d e s . S m a l l doses of rotenone a r e not l e t h a l t o mammals. Ex p e r i m e n t s by v a r i o u s w o r kers have shown t h a t r o t e n o n e a f f e c t s t h e r e s p i r a t o r y system of f i s h e s by p r e v e n t i n g t h e consumption o f oxygen. The i n i t i a l e f f e c t of ro t e n o n e r e s u l t s i n t h e d e g e n e r a t i o n of t h e e p i t h e l i u m o f the g i l l - f i l a m e n t s . T h i s d i s i n t e g r a t i o n o f the s u r f a c e c e l l s p r e v e n t s t h e normal r e s p i r a t o r y f u n c t i o n of the g i l l - f i l a m e n t s . Adequate concen-t r a t i o n s of rotenone a l s o r e s u l t s i n t h e d i s i n t e g r a t i o n of t h e g i l l - f i l a m e n t s of a number of a q u a t i c i n s e c t s and c r u s t a c e a n s . The d i g e s t i v e t r a c t s of f i s h a r e a p p a r e n t l y u n a f f e c t e d by ro t e n o n e . The l o w e s t l e t h a l c o n c e n t r a t i o n of rot e n o n e t h a t would k i l l f i s h w i t h c e r t a i n t y was found t o be 0.5 p.p.m. C e r t a i n f i s h , such as t h e Carp, r e q u i r e up t o 1 p.p.m. t o b r i n g about d e a t h . The c h e m i c a l e r a d i c a t o r used i n t h i s experiment was 54 c a l l e d " F l s h t o x " and was h a n d l e d by t h e Orchard S u p p l y D i s t r i b u t o r s , Wenatchee, Washington, U.S.A. S e v e r a l advantageous p r o p e r t i e s o f t h i s p r o d u c t , amongst which was t h e p r o p e r t y of r a p i d s e l f - d i s p e r s i o n , was a t t r i b u t a b l e t o t h i s c h o i c e of f i s h t o x i c a n t . E s s e n t i a l l y , i t i s a rot e n o n e base compound, w i t h o t h e r i n g r e d i e n t s added t o make i t d i s s o l v e more e a s i l y i n wa t e r and i n c r e a s e i t s l e t h a l e f f e c t . I t i s p o i n t e d out t h a t t h e main d i s a d v a n t a g e i n u s i n g raw powdered r o t e n o n e i s t h a t i t does not d i s s o l v e o r d i f f u s e r e a d i l y t h r o u g h the wa t e r . 55 LABORATORY EXPERIMENT WITH "FISHTOX" An experiment w i t h F i s h t o x was conducted i n t h e l a b o r a t o r y t o ob s e r v e t h e d i r e c t e f f e c t of F i s h t o x on t h e v a r i o u s organisms, and a t d i f f e r e n t t e m p e r a t u r e s . The a n i m a l s used f o r t h e experiment were Gammarus from L a i r d l a k e and c e r t a i n l i m n e t i c p l a n k t o n f r o m C u l t u s l a k e , B.C. The F i s h t o x was t h e same as t h a t u t i l i z e d i n t h e f i e l d e x periment. Four q u a r t s e a l e r s were used as c o n t a i n e r s The p l a n k t o n was c a r e f u l l y d i v i d e d i n t o f o u r e q u a l p a r t s , mixed t h o r o u g h l y , and t h e n poured a l i t t l e a t a t i m e i n t o each of the f o u r c o n t a i n e r s . A s m a l l q u a n t i t y of t a p -water was added t o b r i n g t h e volume up t o one l i t e r . Two Gammarus were t h e n put I n t o each c o n t a i n e r . 1 c c . of an one l i t e r s o l u t i o n c o n t a i n i n g .5 gm. F i s h t o x was t h e n i n t r o d u c e d i n t o two o f t h e f o u r j a r s , g i v i n g them an approximate concen-t r a t i o n of .5 p.p.m. F i s h t o x . The o t h e r two j a r s were u s e d a c o n t r o l j a r s . One c o n t r o l and one e x p e r i m e n t a l j a r were p l a c e d i n d o o r s , t h e temp e r a t u r e r a n g i n g f rom about 18 t o 21°C The o t h e r c o n t r o l and e x p e r i m e n t a l j a r were k e p t i n a g l a s s c o n t a i n e d c o o l e r a t a t e m p e r a t u r e of a p p r o x i m a t e l y 4°. I t s h o u l d be p o i n t e d o u t , perhaps, t h a t a t no time were the c o n t a i n e r s put i n t o d i r e c t s u n l i g h t , a l t h o u g h t h e y had i n d i r e c t l i g h t i n g . A f t e r a 22-hour p e r i o d , t h e j a r s were examined. The c o l d w a t e r c o n t r o l and e x p e r i m e n t a l j a r s t i l l showed v i s i b l e s i g n s o f l i f e by t h e l a r g e r z o o p l a n k t o n . The h i g h 5b t e m p e r a t u r e c o n t r o l j a r a l s o e x h i b i t e d movement by the l a r g e r z o o p l a n k t o n , but i n the e x p e r i m e n t a l j a r , t h e r e was no move-ment of t h e z o o p l a n k t o n . T h i r t y hours a f t e r t h e b e g i n n i n g o f t h e ex p e r i m e n t , b o t h Gammarus I n a l l f o u r j a r s were s t i l l a c t i v e . Moreover, the low tem p e r a t u r e j a r and the h i g h t e m p e r a t u r e c o n t r o l j a r s t i l l showed v i s i b l e s i g n s of l i f e . By means of a p i p e t t e , samples were o b t a i n e d from t h e h i g h t e m p e r a t u r e j a r c o n t a i n i n g the F i s h t o x . On i n s p e c t i n g t h e s e samples under a m i c r o s c o p e , the f o l l o w i n g c o u n t s were made: S p e c i e s Number Number dead a l i v e C y c l o p s 4 0 N a u p l i u s 6 0 Daphnia 1 0 Bosmlna 1 0 N o t h o l c a 2 1 U n i d e n t i f i e d R o t i f e r 0 1 U n i d e n t i f i e d C i l i a t e 0 s e v e r a l I t was noted i n t h e above count, t h a t a l t h o u g h the a d u l t Bosmina was dead, i t c o n t a i n e d two young w h i c h were s t i l l a l i v e . The h i g h t e m p e r a t u r e c o n t r o l j a r was not e a s i l y sampled w i t h a p i p e t t e , and o n l y two s p e c i e s were o b t a i n e d as shown i n the f o l l o w i n g t a b l e : S p e c i e s Number Number dead a l i v e C y c l o p s 2 2 Bosmina 4 5 F o r t y - f o u r hours a f t e r t h e experiment was begun, a l l t h e Gammarus were s t i l l a l i v e . The Gammarus i n t h e h i g h t e m p e r a t u r e e x p e r i m e n t a l j a r , however, showed l i t t l e s i g n s of a c t i v i t y . They tended t o r e m a i n i n one spot and l i e on t h e i r s i d e s , b e a t i n g t h e i r appendages r a p i d l y . I n c o n t r a s t , t h e Gammarus i n t h e r e m a i n i n g t h r e e j a r s swam c o n s t a n t l y about as u s u a l . E x p e r i m e n t a l j a r , 18-21°C. S p e c i e s Number Number dead a l i v e E p l s c h u r a 2 0 C y c l o p s 33 0 C anthoc amptus 0 1 N a u p l i u s 8 0 Daphnia 10 0 Bosmina 26 0 N o t h o l c a 8 0 U n i d e n t i f i e d C i l i a t e 0 4 C o n t r o l j a r , 18-21°C. S p e c i e s Number Number dead a l i v e E p i s c h u r a 0 2 C y c l o p s 3 6 N a u p l i u s 0 1 Daphnia 3 3 Bosmina 5 6 N o t h o l c a 1 0 By t h i s t i m e , t h e p o p u l a t i o n s o f copepods and c l a d o c e r a n s i n t h e low t e m p e r a t u r e e x p e r i m e n t a l j a r had d e c l i n e d as compared w i t h t h e c o n t r o l j a r . Some were s t i l l showing s i g n s o f l i f e . A t t h i s t i m e , no c o u n t s were made i n t h e s e j a r s . 58 After 7 0 hours, "both G-ammarus in the high temperature, experimental jar were dead, while the G-ammarus in the remaining three jars were a l l alive. In addition, in both of the experimental jars, the filamentous Algae appeared much more prolific than that In either of the control jars. In order to obtain a more complete count, No. 10 plankton silk was used to strain out the zooplankton. The jars were decanted and a l l the water except the bottom centi-meter layer, which was concentrated with filamentous Algae, was strained through this cloth. The cloth was then carefully washed, and the organisms placed in a 1 cc. counting slide. A total count of a l l plankton obtained was then made under the microscope, and the results were as tabulated. Total counts were made In a l l cases, except in those indicated with an asterisk when approximately one-fourteenth of the total was counted. Experimental jar, 18-21°C. Species Number Number dead alive Cyclops 3 0 Daphnia 4 0 Bosmina 10 0 In the above table-, i t was noted that these organisms were a l l decomposing. C o n t r o l j a r , 18-21°C. S p e c i e s Number Number dead a l i v e E p i s c h u r a 0 1 C y c l o p s * 0 38 N a u p l i u s * 0 1 Daph.nl a 0 5 0 Bosmina 5 14 N o t h o l e a * 0 1 E x p e r i m e n t a l j a r , 4°C * S p e c i e s Number Number dead a l i v e E p i s c h u r a 1 0 C y c l o p s * 4 0 N a u p l i u s * 8 0 Daphnia 2 • 1 Bosmina 12 0 N o t h o l e a* 2 0 C o n t r o l J a r , 4°C. S p e c i e s Number Number dead a l i v e E p i s c h u r a 0 2 C y c l o p s * 0 25 N a u p l i u s * 0 8 Daphnia 0 28 Bosmina 0 43 Four days from t h e s t a r t o f t h e ex p e r i m e n t , i n t h e e x p e r i m e n t a l J a r kept a t about 4°, one of t h e Gammarus was dead. A f t e r f i v e days, t h e o t h e r Gammarus d i e d i n t h e c o l d e x p e r i m e n t a l c o n t a i n e r w h i l e b o t h Gammarus were s t i l l a l i v e the c o n t r o l J a r . A t t h i s t i m e , o b s e r v a t i o n s were d i s c o n t i n u e d . The experiment i n d i c a t e s c e r t a i n c l e a r - c u t r e s u l t s , f r o m t h e above d a t a . I t I s ap p a r e n t t h a t F i s h t o x i s more 60 e f f e c t i v e on t h e organisms i n warm w a t e r s t h a n i t i s i n c o l d w a t e r s . As was seen, a l l t h e p l a n k t o n Crustacea, except Canthocamptus, were k i l l e d a t about 2 0 ° w i t h i n 22 h o u r s , w h i l e a t about 4 ° , i t took about 7 0 h o u r s f o r p r a c t i c a l l y a complete k i l l t o o c c u r . Moreover, t h e r o t i f e r N o t h o l c a was a b l e t o s u r v i v e a t t h e l o w e r t e m p e r a t u r e . I t must not be o v e r l o o k e d t h a t many more p r o t o z o a n s and r o t i f e r s might have been found a l i v e i f a f i n e r s i l k c l o t h had been used. I t i s a l s o i n t e r e s t i n g t o n o t e t h a t one Daphnia was s t i l l a l i v e a t the end of t h e 7 0-hour p e r i o d . There might be s e v e r a l r e a s o n s advanced f o r t h i s . I n t h e f i r s t p l a c e , t h e d e a t h pf t h e o t h e r organisms might have been s u f f i c i e n t t o n e u t r a l i z e t h e power of t h e F i s h t o x t o k i l l i t . S e c o n d l y , t h i s Daphnia might have been p h y s i o l o g i c a l l y a b l e t o a d j u s t i t s e l f t o t h e l e t h a l e f f e c t of F i s h t o x . T h i r d l y , t h e Daphnia might have d e v e l o p e d a f t e r t h e maximum e f f e c t of t h e t r e a t m e n t ' was o v e r . The Gammarus r e a c t e d t h e same as t h e l i m n e t i c C r u s t a c e a except t h a t t h e y were a b l e t o r e s i s t t h e l e t h a l e f f e c t s o f t h e F i s h t o x f o r a l o n g e r p e r i o d o f t i m e . U l t i m a t e l y , t h e i r f a t e was t h e same. S e v e r a l c o n c l u s i o n s can be drawn from t h i s e x periment. 1 . A c o n c e n t r a t i o n of . 5 p. p.m. of F i s h t o x i s l e t h a l t o most z o o p l a n k t o n , e s p e c i a l l y t h e C r u s t a c e a . However, t h e r e i s e v i d e n c e t o i n d i c a t e t h a t c e r t a i n members i n t h e p l a n k t o n p o p u l a t i o n w i l l s u r v i v e t h e e f f e c t s of t h e t r e a t m e n t . 2. Amphipods, such as Gammarus, can s u r v i v e l o n g e r t h a n l i m n e t i c C r u s t a c e a , such as E p i s c h u r a , C y c l o p s , Daphnia and Bosmina, but t h e u l t i m a t e e f f e c t of t h e F i s h t o x i s l e t h a l t o them. 3 . The C r u s t a c e a , t r e a t e d w i t h F i s h t o x , l i v e d l o n g e r a t low t e m p e r a t u r e s t h a n a t h i g h t e m p e r a t u r e s . 62 FIELD APPLICATION As mentioned i n the i n t r o d u c t i o n , i t was n e c e s s a r y t o r u n a c o n t r o l l e d f i e l d e x p eriment t o t e s t t h e pros and cons of the " c o a r s e " f i s h problem. T h i s was n e c e s s a r y f o r r e a s o n s o u t l i n e d i n a p r e l i m i n a r y r e p o r t by MacPhee (1948). L i k e t h e experiment o u t l i n e d i n the l a b o r a t o r y , i t was n e c e s s a r y t o use a t l e a s t one l a k e f o r an e x p e r i m e n t a l l a k e and a t l e a s t one l a k e f o r a c o n t r o l l a k e . I n 1947, s i n c e the One-Mile l a k e s l a y i n but a s m a l l a r e a , i t was d e c i d e d t h a t i t would be an advantage t o use two of them as e x p e r i m e n t a l l a k e s and two o f them as c o n t r o l l a k e s . S i n c e , I n most y e a r s , D r y and Borgeson l a k e s were not con n e c t e d w i t h t h e r e s t of t h e s e r i e s o f l a k e s , due t o t h e i r d r y s t r e a m beds, m i g r a t i o n i n and out o f the l a k e s would be reduced t o a minimum. F o r t h i s r e a s o n , t h e y were chosen f o r the e x p e r i m e n t a l l a k e s t o be t r e a t e d w i t h F i s h t o x . L a i r d and M c C a f f e r t y were chosen f o r t h e c o n t r o l l a k e s , because t h e y were a p p r o x i m a t e l y t h e same s i z e as t h e e x p e r i m e n t a l l a k e s . I n 1948, A l l i s o n l a k e , a t t h e head o f t h e s e r i e s , was a l s o l i m n i l o g i c a l l y surveyed w i t h t h e view t h a t the d a t a might prove of some v a l u e f o r c o m p a r a t i v e purposes. I n view o f t h e l a b o r a t o r y e x p e r i m e n t , i t was n e c e s s a r y t o a p p l y t h e F i s h t o x when wa t e r t e m p e r a t u r e s were h i g h e s t . I t was a l s o n e c e s s a r y t o t a k e i n t o c o n s i d e r a t i o n t h e water l e v e l s i n t h e l a k e s , s i n c e i t was o b v i o u s l y b e t t e r t o p o i s o n Dry l a k e a t i t s l o w e s t l e v e l . As was shown under t h e sub-heading "Mean t e m p e r a t u r e , " t h e e q u i t h e r m a l p l a t e a u s t i l l e x i s t e d a t t h e l a s t t e m p e r a t u r e s r e c o r d e d f o r August of t h a t y e a r , so t h a t i t seemed l i k e l y t h a t the h i g h mean te m p e r a t u r e would c o n t i n u e t o e x i s t i n t h e e a r l y p a r t of September. Moreover, t e m p e r a t u r e s t r a t a a re l e s s pronounced l a t e r i n the season and a b e t t e r d i s p e r s i o n of F i s h t o x was a s s u r e d . I n view o f t h e s e above f a c t s , t h e e a r l y p a r t o f September was chosen f o r t r e a t i n g t h e l a k e s . I n g e n e r a l , the p r o c e d u r e used f o r d i s t r i b u t i n g F i s h t o x was t h e same f o r t h e e x p e r i m e n t a l l a k e s as t h a t used f o r d i s t r i b u t i n g cube powder i n G u l l l a k e , C a l i f o r n i a ( V e s t a l 1942). Dry l a k e was t r e a t e d on September 7, 1947. Buoys were anchored a t approximate i n t e r v a l s , so t h a t t h e l a k e ' s volume was d i v i d e d t r a n s v e r s e l y i n t o f o u r more or l e s s e q u a l s e c t i o n s . A two-man power boat was d e t a i l e d t o work each s t a t i o n . An a l l o t m e n t of 2,280 pounds of F i s h t o x was d i v i d e d e q u a l l y i n t o f o u r p a r t s and p l a c e d a t a handy l o c a t i o n o p p o s i t e each s e c t i o n o f t h e l a k e . Each b o a t c o l l e c t e d i t s s u p p l y of F i s h t o x from i t s a p p r o p r i a t e s t a t i o n . B orgeson l a k e was t r e a t e d on September 8, 1947,. w i t h 2,480 pounds of F i s h t o x . I t was d i v i d e d i n t o f o u r p a r t s l i k e -w i s e , except t h a t due t o t h e shape of t h e l a k e , a buoy was p l a c e d i n t h e c e n t r e and the l a k e was d i v i d e d q u a d r i l a t e r a l l y . F u r t h e r m o r e , one c e n t r a l depot was used i n s t e a d of f o u r . The F i s h t o x was put i n t o gunny s a c k s equipped w i t h two ropes and t h e opening t i e d . The sack was t h e n l o w e r e d i n t h e 64 wake o f the b o a t ' s motor and worked back and f o r t h by means of the two ropes u n t i l a l l t h e F i s h t o x had f i l t e r e d t h r o u g h t h e pores o f the sack as t h e bo a t t r a v e l l e d back and f o r t h a c r o s s the l a k e . V o l u n t e e r s were p r e s e n t a t each of t h e depots t o keep t h e power b o a t s s u p p l i e d . S t r o n g s o l u t i o n s of F i s h t o x were p r e p a r e d and back-pumps were u s e d f o r s p r a y i n g i t i n t o t h e weed beds. About 6 t o 8 hours were r e q u i r e d t o c o m p l e t e l y t r e a t each l a k e . By d i v i d i n g the w e i g h t of F i s h t o x by t h e weight of water i n Dry l a k e and Bor g e s o n l a k e , the c o n c e n t r a t i o n o f F i s h t o x o f the t r e a t e d w a t e r s was e s t i m a t e d t o be .83 p.p.m. f o r D r y l a k e and . 7 6 p.p.m. f o r Borgeson l a k e . 65 R E S U L T S EFFECT ON PLANKTON Ap p a r a t u s and c o l l e c t i o n e r r o r s The p l a n k t o n n e t s used i n t h e s e s t u d i e s were m o d i f i c a t i o n s o f the " W i s c o n s i n " t y p e (Juday 1916) w i t h a t o p canvas t r u n c a t e d cone 35 cm. l o n g and a f i l t e r i n g cone 78 cm. l o n g , . w i t h a c e n t r e - p i e c e of s i l k 60 t o 65 cm. l o n g and a r e a w h i c h v a r i e d w i t h the n e t s of f r o m 2,900 t o 3,100 sq. cm. The a p e r t u r e o f t h e p l a n k t o n n et had an i n s i d e d i a m e t e r o f 22.5 cm. The second r i n g a t t h e base of t h e t o p t r u n c a t e d cone had an i n s i d e d i a m e t e r o f 28 cm. The bu c k e t had an i n s i d e d i a m e t e r of 5«2 cm. and a s i l k f i l t e r i n g a r e a o f 73 sq.cm. One p l a n k t o n n e t was made up of No. 20 b o l t i n g s i l k and a n o t h e r of No. 10 b o l t i n g s i l k . New p l a n k t o n n e t s were used each season. P l a n k t o n n e t s were p r e - s h r u n k ( s h r i n k a g e o f No. 20 n e t s was measured as 14 per c e n t ; f o r No. 10 n e t s , s h r i n k a g e i s n e g l i g i b l e ) . The pores of t h e No. 20 net were much s m a l l e r a t the end o f the season, due t o s p r e a d i n g of t h e t h r e a d s and c l o g g i n g up of t h e h o l e s between t h e t h r e a d s by d e s i c c a t e d p l a n k t o n . A count of 49 h o l e s o f the s i l k t a k e n from an used p l a n k t o n b u c k e t showed t h a t 22 squares were c o m p l e t e l y c l o g g e d , m o s t l y by P e r i d l n i u m and F r a g l l l a r i s , 8 squares were c l o g g e d a t t h e c o r n e r s w i t h p l a n k t o n and 19 squares were about h a l f c l o g g e d . The a r e a of t h e pores i n t h e s i l k o f a w e l l 66 used f i l t e r i n g cone was reduced from a p p r o x i m a t e l y f:@. 0 0 5 0 t o 0 . 0 0 0 7 sq. - mm. T h i s would i n d i c a t e t h a t l o s s of e f f i c i e n c y on a c c o u n t of s h r i n k a g e would be n e g l i g i b l e compared w i t h t h e l o s s due t o t h e d e c r e a s e i n s i z e o f t h e pores by c l o g g i n g . The pores of t h e No. 10 p l a n k t o n n e t showed no c l o g g i n g . The e f f i c i e n c y o f t h e No. 20 net v a r i e s w i t h t h e r a t e a t w h i c h the pores of t h e s i l k become c l o g g e d w i t h p l a n k t e r s . I t was noted t h a t c e r t a i n s p e c i e s , such as S t e n t o r , c l o g the p l a n k t o n s i l k v e r y r a p i d l y (on May 10, 1948 i n Borgeson l a k e , t h i s s p e c i e s was p a r t i c u l a r l y abundant). The r a t e a t w h i c h t h e net c l o g s v a r i e s w i t h t h e v a r i e t y and abundance o f s p e c i e s p r e s e n t a t t h e time as w e l l as w i t h t h e i r v e r t i c a l d i s t r i b u t i o n . I n a d d i t i o n , t h e e f f i c i e n c y o f t h e No. 20 net v a r i e s w i t h t h e l e n g t h o f t h e v e r t i c a l h a u l . Abundance o f s p e c i e s and l e n g t h of h a u l , however, a r e i n t e r r e l a t e d f a c t o r s b o t h c o n t r i b u t i n g t o l o s s i n e f f i c i e n c y . F o r t h e above r e a s o n s , t h e , q u a n t i t a t i v e e f f i c i e n c y of No. 20 p l a n k t o n n e t s a r e n o t comparable. The r a t e of e f f i c i e n c y l o s s i s p r o b a b l y i n t h e n a t u r e o f a g e o m e t r i c p r o g r e s s i o n . I n o t h e r words, a t t h e b e g i n n i n g of a v e r t i c a l h a u l , t h e e f f i c i e n c y of a No. 20 net would be c l o s e t o 100 per cent . T h e o r e t i c a l l y , t h i s i n i t i a l e f f i c i e n c y would be l o s t v e r y r a p i d l y as t h e pores c l o g g e d and, d u r i n g t h e remainder of t h e h a u l , a g r a d u a l l y d e c l i n i n g , v e r y low e f f i c i e n c y would r e s u l t . F o r t h i s r e a s o n , t o t a l v e r t i c a l h a u l s a r e p r o b a b l y more q u a n t i t a t i v e l y r e p r e s e n t a t i v e of t h e l o w e r s t r a t a i n t h e l a k e s t h a n o f t h e upper s t r a t a . 67 F u r t h e r m o r e , any v a r i a t i o n i n t h e l e n g t h o f t h e t o t a l v e r t i c a l h a u l s o f a s m a l l n a t u r e (1-2 m.), such as o c c u r r e d i n t h e s a m p l i n g of t h e One-Mile l a k e s can be n e g l e c t e d , because t h e d i f f e r e n c e i n t h e amount of p l a n k t o n c o l l e c t e d would be t h e o r e t i c a l l y s m a l l a t t h e l o w e r e f f i c i e n c i e s . Other e r r o r s , i n h e r e n t i n s a m p l i n g w i t h p l a n k t o n n e t s , a r e g i v e n by R i c k e r (1932) and were as f a r as p o s s i b l e e l i m i n a t e d . R i c k e r (1937) p o i n t s out t h a t No. 10 s i l k i s a r e l i a b l e q u a n t i t a t i v e c o l l e c t o r o f t h e l a r g e r organisms. P l a n k t o n c o l l e c t i o n s P l a n k t o n samples were t a k e n a t t h e same t i m e and a t the same s t a t i o n s as oxygen samples and te m p e r a t u r e r e c o r d s . To a v o i d e r r o r s i n comparisons, due t o d i u r n a l m i g r a t i o n , p l a n k t o n c o l l e c t i o n s were t a k e n as near noon as was p r a c t i c a l i n a l l o f the l a k e s . The r a t e o f h a u l was a p p r o x i m a t e l y 0.5 m. per second. I n 1947, t h e p l a n k t o n c o l l e c t i o n s were made up of t h r e e v e r t i c a l h a u l s t a k e n one a f t e r t h e o t h e r . T h i s procedure was f o l l o w e d on May 9 and May 10 i n 1948 f o r M c C a f f e r t y , L a i r d and Dry l a k e s , b u t f o r Borgeson l a k e , two v e r t i c a l h a u l s were made w i t h t h e No. 10 net and o n l y one h a u l was t a k e n w i t h the No. 20 n e t . F o r A l l i s o n l a k e a t t h i s time and f o r a l l the l a k e s t h r o u g h o u t the remainder o f 1948, p l a n k t o n c o l l e c t i o n s were composed of j u s t one h a u l . I n 1947, on the f i r s t f o u r d a t e s p l a n k t o n was sampled, t h r e e , a p p r o x i m a t e l y e q u a l , s t a g e h a u l s were t a k e n w i t h No. 20 net f r o m L a i r d , D ry and Bor g e s o n l a k e s and two from M c C a f f e r t y 6 8 l a k e . T o t a l v e r t i c a l h a u l s were t a k e n w i t h t h e No. 20 net a t . t h e same t i m e . R i c k e r (1932) s t a t e s t h a t i f a net i s used f o r a s e r i e s of h a u l s , and i s not d r i e d t h o r o u g h l y between each, t h e n i t s e f f i c i e n c y f a l l s t h r o u g h o u t t h e s e r i e s , r a p i d l y a t f i r s t and more s l o w l y l a t e r . Because t w e l v e h a u l s were made i n s u c c e s s i o n a t t h e s e t i m e s , t h e r e l a t i v e e f f i c i e n c y of t h e net was reduced. V o l u m e t r i c , g r a v i m e t r i c and en u m e r a t i o n d a t a . The s e t t l e d volumes, c e n t r i f u g e volumes and d r y w e i g h t s o f t h e p l a n k t o n c o l l e c t i o n s f o r t h e t o t a l v e r t i c a l h a u l s t a k e n w i t h t h e No. 20 p l a n k t o n n et were d e t e r m i n e d . The r e m a i n i n g c o l l e c t i o n s were a n a l y z e d v o l u m e t r i c a l l y o n l y . Graduated 15 c c . c e n t r i f u g e tubes were used f o r measuring s e t t l e d volumes o f p l a n k t o n . C e n t r i f u g e volumes were o b t a i n e d a f t e r c e n t r i f u g i n g t h e p l a n k t o n a t 2,000 r.p.m. f o r t e n minutes. D r y w e i g h t s were r e c o r d e d a f t e r t h e p l a n k t o n had been d r i e d f o r a t l e a s t 24 hour s a t 60°C. A comparison o f t h e s e t h r e e methods of a n a l y s i s was made. The r e s u l t s from 24 samples were used and each method of a n a l y s i s was c o r r e l a t e d w i t h each of t h e o t h e r methods. The c o r r e l a t i o n c o e f f i c i e n t s were found as f o l l o w s : S e t t l e d volumes v e r s u s c e n t r i f u g e volumes r-|_ - .9826 S e t t l e d volumes v e r s u s d r y w e i g h t r 2 = .9^96 C e n t r i f u g e volumes v e r s u s d r y w e i g h t r ^ - . 9 5 5 1 There i s no s i g n i f i c a n t d i f f e r e n c e between the most extreme of t h e s e c o r r e l a t i o n c o e f f i c i e n t s ( r ^ v e r s u s r2> •V 69 t z 1.8, P = .05 - .10). As a r e s u l t of t h i s , t h e d e t e r m i n a t i o n o f d r y w e i g h t s was d i s c o n t i n u e d . . Enumeration of t h e p l a n k t e r s was a c c o m p l i s h e d by e s t i m a t i n g t h e t o t a l number from b u t a f r a c t i o n of t h e c o l l e c t i o n . Each c o l l e c t i o n was t r a n s f e r r e d t o a s p e c i a l g r a d u a t e and t h e volume made up t o 23 c c . A l c c . c y l i n d e r , 7 mm. i n d i a m e t e r , was so d e s i g n e d t h a t i t c o u l d t a k e a complete v e r t i c a l s e c t i o n f r o m t h e g r a d u a t e . A f t e r t h o r o u g h l y m i x i n g , the c y l i n d e r was used t o t r a n s f e r a p o r t i o n o f the c o l l e c t i o n t o a 1 c c . c o u n t i n g s l i d e . Depending on t h e s i z e and numbers of p l a n k t e r s , e i t h e r a t o t a l count of t h e s l i d e 1 o r , by means of a Whipple d i s k , t e n d i f f e r e n t a r e a s of t h e s l i d e were counted. I n the case o f the p h y t o p l a n k t o n and c e r t a i n of the s m a l l p r o t o z o a n s , t h e f i r s t v o l u m e t r i c f r a c t i o n was f u r t h e r f r a c t i o n e d o n e - t e n t h , v o l u m e t r i c a l l y , and t r a n s f e r r e d t o a c o u n t i n g s l i d e . Ten d i f f e r e n t a r e a s were counted and the t o t a l numbers e s t i m a t e d . T h i s l a t t e r p r o c e d u r e was n e c e s s a r y , because t h e l a r g e r p l a n k t e r s tended t o s h i e l d t h e s m a l l e r from v i e w , and i f the: s o l u t i o n were not s u f f i c i e n t l y d i l u t e d , t h i s s h i e l d i n g would r e s u l t i n n o t i c e -a b l e e r r o r s . R i c k e r (1937) s t a t e s t h a t , of the v a r i o u s k i n d s o f e r r o r s w hich a r i s e i n q u a n t i t a t i v e p l a n k t o n i n v e s t i g a t i o n s , t h o s e i n v o l v e d I n t h e p r o c e s s o f enumeration of a c o l l e c t i o n a r e o r d i n a r i l y s m a l l e s t i n magnitude, though f r a c t l o n i n g may produce an e x t r a s a m p l i n g e r r o r when not done v o l u m e t r i c a l l y . Care was e x e r c i s e d i n t h e e n u m e r a t i o n of t h e c o l l e c t i o n s , however, and i n many i n s t a n c e s , a check was made on t h e P L A N K T O N C O L L E C T I O N S - N O . 2 0 N E T T O T A L H A U L S S U M O F S T A G E H A U L S JULY AUG. AUG. AUG SEPT SIPT JULY AUG. AUG AUG T O T A L H A U L S 1 9 4 8 MAY JUNE JULY " AUG. SEPT. F I G U R E XIII 71 f r a c t i o n i n g p r o c e d u r e . P e r c e n t a g e volume a n a l y s e s were o b t a i n e d by m u l t i p l y i n g t h e e s t i m a t e d number o f p l a n k t e r s i n t h e c o l l e c t i o n s by t h e volume of t h e p l a n k t e r concerned, minus appendages. Volumes were measured as suggested by Welsh (1948). The d a t a f o r the v o l u m e t r i c and g r a v i m e t r i c a n a l y s e s i s p r e s e n t e d i n T a b l e s XX t o XXIV I n c l u s i v e . Graphs of s e t t l e d volumes a r e shown i n F i g u r e s X I I I and XIV, and because the 1947 p l a n k t o n c o l l e c t i o n s c o n s i s t e d of t h r e e h a u l s , t h e volumes r e p r e s e n t e d by t h e graphs were r o u g h l y c o r r e c t e d t o r e p r e s e n t one h a u l by d i v i d i n g by t h r e e . The d a t a f o r e s t i m a t e d numbers of p l a n k t e r s f o u n d i n t h e c o l l e c t i o n s a r e g i v e n i n T a b l e s XXVI t o XXX I n c l u s i v e , e x c e p t f o r s t a g e c o l l e c t i o n s w h i c h were not enumerated. C e r t a i n p l a n k t e r s have been graphed and a r e shown i n F i g u r e s XV and XVI. T a b l e XXV g i v e s the c a l c u l a t e d p e r c e n t a g e volumes of phyto-p l a n k t o n , P r o t o z o a , R o t i f e r a and E n t o m o s t r a c a c o n t a i n e d i n t h e No. 20 net p l a n k t o n c o l l e c t i o n s f o r t o t a l h a u l s . For 1947, t h e f i g u r e s f o r a l l s t a g e and v e r t i c a l h a u l s r e p r e s e n t one h a u l w i t h the e x c e p t i o n t h a t the c o l l e c t i o n s made on May 9 and May 10, 1948 were c o r r e c t e d t o r e p r e s e n t one h a u l . The two graphs showing t h e s e t t l e d volumes of t h e 1947 No. 20 net p l a n k t o n c o l l e c t i o n s i n d i c a t e t h a t the volume of p l a n k t o n i n the One-Mile l a k e s was on the d e c l i n e . A p e r c e n t -age volume a n a l y s i s o f t h e E n t o m o s t r a c a i n t h e c o n t r o l l a k e s and b e f o r e the a p p l i c a t i o n o f F i s h t o x i n t h e e x p e r i m e n t a l P L A N K T O N C O L L E C T I O N S — N O . 1 0 N E T FIGURE XIV 75 l a k e s showed w i t h one e x c e p t i o n t h a t t h e c o l l e c t i o n s c o n t a i n e d 87 per cent o r more of t h e s e C r u s t a c e a , of w h i c h Daphnia  l o n g l s p l n a , C e r i o d a p h n i a q u a d r a n g u l a and C y c l o p s v l r l d l s were the dominant s p e c i e s . On August 16, 194-8, M c C a f f e r t y had a bloom o f t h e p h y t o p l a n k t e r , F r a g i l l a r l a and a p u l s e of the p r o t o z o a n , Dynobryon, b o t h o f which c o n t r i b u t e d t o re d u c e t h e pe r c e n t a g e volume of entomostracans t o a p p r o x i m a t e l y 63 per cent. Because no c o l l e c t i o n s were made i m m e d i a t e l y b e f o r e o r a f t e r t h e t r e a t m e n t w i t h F i s h t o x , t h e d i r e c t e f f e c t of the sub s t a n c e on the volume of p l a n k t o n was n o t . d e t e r m i n e d . A f t e r the t r e a t m e n t , t h e change i n t h e t o t a l volume of p l a n k t o n i n the e x p e r i m e n t a l l a k e s between September 11 and 19 was not _ marked. A f t e r t h e a p p l i c a t i o n of F i s h t o x i n Dry l a k e , t h e Ento m o s t r a c a were reduced t o l e s s t h a n 50 per cent of t h e volume o f the c o l l e c t i o n s , b e i n g r e p l a c e d by Anabaena, F r a g l l l a r l a and Dynobryon. I t was not u n t i l e i g h t days a f t e r t h e t r e a t m e n t i n Borgeson l a k e t h a t a marked d e c r e a s e i n t h e pe r c e n t a g e volume o f En t o m o s t r a c a o c c u r r e d . F r a g i l l a r i a , Dynobryon, P o l y a r t h r a and Daphnia were the dominant r e p r e s e n t -a t i v e s o f the p h y t o p l a n k t o n , P r o t o z o a , R o t i f e r a and En t o m o s t r a c a r e s p e c t i v e l y i n Bo r g e s o n l a k e a t t h i s time. F i g u r e XIV g i v e s a c l e a r i n d i c a t i o n of t h e c o n t i n u i n g e f f e c t s o f F i s h t o x on t h e p l a n k t o n i n the e x p e r i m e n t a l l a k e s the f o l l o w i n g y e a r . P l a n k t o n c o l l e c t i o n s of t h e c o n t r o l l a k e s and A l l i s o n l a k e show a r a p i d i n i t i a l i n c r e a s e i n volumes. By c o n t r a s t , t h e r e i s no marked i n c r e a s e i n volumes o f p l a n k t o n i n Dry and Borgeson l a k e s u n t i l J u l y . E x c e p t on August 6, P L A N K T O N T R E N D S - ( N O . 2 0 N E T ) C Y C L 0 P S - I 9 4 7 MAY JUNE JULY AUG. SEPT. OCT. FIGURE XV 75 1948, when a p u l s e of Dynobryon o c c u r r e d i n M c C a f f e r t y l a k e , t h e E n t o m o s t r a c a composed a t l e a s t 79 per c e n t o f the t o t a l volumes o f t h e c o l l e c t i o n s . A g a i n , i n 1948, t h e y formed a t l e a s t 87 per cen t of t h e c o l l e c t i o n s f r o m L a i r d l a k e . A l l i s o n l a k e c o l l e c t i o n s c o n t a i n e d a minimum of 80 per cent C r u s t a c e a , e x c e p t f o r an i n i t i a l c o l l e c t i o n t a k e n from t h a t l a k e on May 5, 1948, c o n t a i n i n g a l a r g e bloom of M i c r o c y s t i s . On the o t h e r hand, b o t h Dry and Borgeson showed a v e r y slow r e c o v e r y of C l a d o c e r a and Copepoda. I n Dry l a k e , on May.10, 1948, t h e r o t i f e r , T r l a r t h r a a c c o u n t e d f o r 79 per cent and t h e copepod, Diaptomus, 17•5 per cent o f the t o t a l volume of t h e No. 20 net p l a n k t o n c o l l e c t i o n . On May 31, t h e percentage o f T r l a r t h r a was s t i l l s l i g h t l y g r e a t e r , w h i l e t h a t of Diaptomus had d e c l i n e d t o l e s s t h a n 9 per c e n t . By J u l y 5, t h e E n t o m o s t r a c a had i n c r e a s e d t o 39 per cent w h i l e t h e r o t i f e r s had d e c r e a s e d t o about 3 0 per c e n t . A t t h i s t i m e , Daphnia l o n g l s p l n a , T r l a r t h r a , Dynobryon and A s t e r i o n e l l a were the Imp o r t a n t p l a n k t e r s . On J u l y 15, due t o a bloom of Gonophosphaerla and A s t e r i o n e l l a , the phyto-p l a n k t o n formed 58.5 per cen t of t h e p l a n k t o n c o l l e c t i o n . U r o g l e n a , T r l a r t h r a and D. l o n g l s p l n a were t h e dominant p l a n k t e r s of t h e i r groups. On August 7, t h e Ent o m o s t r a c a , w i t h D. l o n g i s p i n a dominant, f i n a l l y came back t o the 90 per cent l e v e l found i n Dry l a k e p r e v i o u s t o i t s F i s h t o x t r e a t -ment. On September 3, a f a l l p u l s e o f Dynobryon formed 32 per cent o f t h e c o l l e c t i o n and t h e p e r c e n t a g e o f Ent o m o s t r a c a was reduced. By October 9, t h e volume o f p l a n k t o n was much ' i n ft Ct 2 < O X I-P L A N K T O N T R E N D S - T R I A R T H R A - 1 9 4 7 (NO. 20 NET) POISONED i • o e 10 20 30 MAY —r— 10 20 30 10 20 30 JUNE JULY 10 20 30 AUG. 20 3 0 10 SEPT. OCT. FIGURE XVI 77 reduced, the Entomostraca, s t i l l mainly D. longlspina, again reverting back to a 9 0 per cent level. In Borgeson lake, the other poisoned lake, the Entomostraca did not increase sufficiently to show in "the count until July 6, 1948. In this group, Cerlodaphnla was dominant until July 26, after which Daphnia pulex formed about 9 0 per cent of the total volumes of the remaining collections. On May 10, 1948, the protozoans, Stentor chiefly and Dynobryon, formed the largest volume of the collection. On May 31, Triarthra formed 87 per cent of the plankton collection. By July 6, although Triarthra had increased over 5 0 per cent in numbers, the volume i t occupied was reduced to about 17 per cent. The protozoan, Bursaria was now the dominant plankter, followed by Uroglena and Stentor, the three making up about 72.5 per cent of the total volume of the collection. By July 16, over 5 0 per cent of the collection was Crustacea, the dominant members of the other groups being Microcystis, Bursarla and Asplanchna. Asplanchna was the dominant rotifer In the remainder of the collections. Among the Protozoa, Uroglena was dominant July 26 and August 7, Dynobryon on September 4 and October 9. The extremely large volume of the plankton collection taken on October 9 was due to a pulse of D. pulex. On comparing the dominant plankton populations before and after the use of Fishtox, its effect was either unpredictable or negligible, with the following exceptions: 78 1. As shown in Figure XV, Fishtox reduced the Cyclops populations markedly in both the experimental lakes: 2. As shown in Tables XXVII and XXVIII, Fishtox delayed the growth of Daphnia long!spina and Diaptomus populations until July of the following year. 3. Figure XVI shows a spring peak in the Trlarthra population in both Dry and Borgeson lakes but none in the other lakes. The fact that a lauger application of Fishtox was used in Dry lake might be responsible for the almost complete absence of the large rotifer, Asplanchna. In 1948, certain protozoans and cladocerans were present in the collections from the experimental lakes that were not observed in the control lakes the same.year, not in either the control or experimental lakes in 1947. Stentor showed in the collection taken May 10, 1948 from Dry lake. It was present in Borgeson lake until September 4, 1948, the maximum numbers appearing in the spring collections. Bursaria showed on May 10 and May 31 in Dry lake and from July 6 to 26 in Borgeson lake. In Dry lake, although Slda was obtained in the bottom dredge in 1947, i t had apparently increased its range so that i t was obtained also with the plankton net in 1948. Chydorus and Daphnia pulex were present in the collections in both the experimental lakes following their treatment with Fishtox. D. pulex completely superseded D. longlspina in Borgeson lake in the f a l l . Daphnia dentlfera in Dry lake and Alona quadrangularla in Borgeson lake also showed up for the f i rs t time in the plankton collections. 80 EFFECT ON BOTTOM ORGANISMS A standard Ekman dredge was used for collecting bottom organisms. The area of its jaws was 1/20 sq. m. No screens were held beneath the dredge on l i f t i n g samples into the boat. In 1947, two screens, one, with 12 meshes to the inch, were used to s i f t out the bottom organisms. In 1948, a 10 and 20 mesh screen were used. In order to make the samples comparable when dredging weed areas, care was taken to trim off any excess weed which protruded from the dredge. Where weeds were relatively poor, certain amounts of bottom deposits fcere included with the weed samples making for an unpredictable error in expressing results. Bottom collection stations are shown in Figures II-VI. Tables XXXI to XXXV give a summary of the dredging results for the five lakes for both 1947 and 1948. Numbers and net weights of organisms and fry weights of weed are given. Molluscs have not been treated quantitatively. No s i g n i f i -cant -correlation was found between abundance of bottom fauna and abundance of weed in the limited number of samples taken. The number of organisms per square meter of weed bottom was less in Dry and Allison lakes which had fluctuat-ing water levels and which were dominated by Polygonum and Potemegetan than the number found in McCafferty, Laird and Borgeson lakes which had stable water levels and which were ( 81 dominated by Cbara . Borgeson lake was the only lake that showed a noticeable difference in the abundance of weed organisms, dropping in 1948 to about 20 percent of the 1947 value. The drop was due largely to a reduction ,$n the amount of Gammarus present in the weeds. The deep waters of Borgeson and Allison lakes were lower in bottom fauna than McCafferty, Laird and Dry lakes. This was in keeping with the supply of oxygen found in the deeper waters of these lakes. On September 3, 1948, in Dry lake at a depth of 13.5m., 182'Chaoborus were taken in one bottom dredging. The Cladocera obtained in the bottom dredge were as follows: 1948 1947 No. of No. .of Species Individuals Borgeson l Dry 2 Laird 0 McCafferty 0 1 10 0 0 No. of No. of Species Individuals 4 433 (407D.pulex) 5 59 (40 Eurycersus) 2 4 1 25 (Eury cercus) Bottom samples, taken in Dry lake on September 12, 1947, showed that the bottom organisms were only partially affected five days after the poisoning. In one dredging, at a depth of 13m., 14 Oligochaeta, 4 Chironomus and 1 Chaoborus larva were collected and were a l l found to be alive. In one dredging, at a depth of 1 m. In 39.4 gm. of weed, 11 Hyalella out of 21 and 1 chironomid out of 2 were found to be dead. Two small aquatic beetles were found, alive. 82 Bottom samples taken in Borgeson lake on September 11, 1947, three days after the poisoning, also showed that they were only partially affected. In one dredging, at a depth of 10 m., 29 chironomids were found dead out of 45. In one dredging, at a depth of 1 m. containing 150 gm. of weed, only one Aeschna nymph was found dead, the remainder of the organ-isms being alive. These included 6 dragon fly njunphs which included one Aeschna nymph, 5 damsel fly mymphs, 2 caddis fly larvae, 5 amphlpods and 2 ollgochaeta. Dead leeches were collected amongst the rocks at the water's edge of Dry lake after the poisoning. Several large ollgochaeta were found . dead in a pool below the outlet of Borgeson lake. 8 3 -EFFECT ON SHORE ORGANISMS In 1948 only, shore collections were made with a special spoon-shaped dip net having 10 meshes to the inch. Collections were made on the same dates that the plankton and bottom collections were made. Approximately, the same time was spent collecting shore organisms at each lake. The purpose of the shore samples was qualitative rather than quantitative and the species collected are noted in Table XVIII. Exclusive of Molluscs, the numbers of species obtained from the One-Mile lakes were as follows: McCafferty 2 Laird 7 Dry 17 Borgeson 18 Allison 4 In Dry lake, beetle larvae were particularly abundant. In the lower four lakes, Ennallagma and Ameletus were plentiful Inshore. During July and early August, certain areas of Dry lake were black with toad tadpoles. Although tadpoles were not seen, 1 Salamander larva was collected In Borgeson lake. 84 EFFECT ON FISH POPULATIONS Leonard (1938), Brown and Ball (1942 and Vestal (1942) have noted the general reaction of fish in waters treated with Rotenone. During the poisoning of the One-Mile lakes, the smaller, inshore fish were affected f i r s t . The order in which the various species of fish were affected was not ascertained., After the poisoning, squawflsh and sculplns remained on the bottom, the latter migrating shoreward. The limit of the depth range of the sculpins was approximately 2m. An idea of their prevalence in Borgeson lake before the poisoning may be gained from the fact that 2 bottom dredgings out of 15 caught live sculpins. On being poisoned, the Kokanee surfaced and could be procured with dip nets. On dying, some remained at the surface and some sank to the bottom. Most of the suckers, chub, shiners and whitefish remained at the surface. Only two kamloops trout were obtained from Borgeson lake and none from Dry lake, so the effect of the poison on this species was not ascertained. Netting with g i l l nets before the poisoning gave no evidence of the numbers of kokanee in the lakes. In each lake, preceding the poisoning, a graduated series of six nets were set, the mesh size ranging from 1% Inches to 4 Inches. Out of a total of 857 f ish, only 17 kokanee were netted in Dry "lake, and'from Borgeson lake, only 3 kokanee were .obtained out of 688 f ish . After the poisoning of Borgeson lake, 500.kokanee were counted around half the shore-line, 85 forming a large portion of the species present. About two weeks after the poisoning, three nets were set for three nights in both experimental lakes and no fish were netted. Furthermore, no signs of live fish were seen following the poisoning of the lakes that f a l l or the following spring. Due to flood conditions, Allison lake overflowed in 1948 and lake shiners and two large suckers were seen in Borgeson lake that summer. No fish were seen in Dry lake although i t is possible that certain eastern brook trout and Kamloops trout which were seen in the stream below Dry lake during the flood, could have migrated into the lake. 86 DISCUSSION Smith (1939) and (1940) found that rotenone as contained in dprrls and cube powders killed planktonic Crustacea. Nevertheless, he found that a certain number of cladocerans and copepods survived the treatment and were able to repopulate the lake, although, not appreciably until the following spring. Brown and Ball (1942) found that Daphnia ,. Dlaptomus and Cyclops populations dropped after the poisoning with rotenone. Moreover, they found that rotifers were reduced on comparing the same period with that of the preceding year. In the One-Mile lake studies, on comparison with the control lakes, Fishtox reduced the percentage volume of Entomostraca in the plankton collections to approximately one-half that which they occupied before the poisoning. The difference in the depths of the lakes and the concentration of Fishtox used probably accounts for the slower reductions of Crustacea which occurred in Borgeson lake. Analyses of the trends of the individual plankter populations immediately before and after the poisoning were inconclusive on comparing the experimental with the control lakes. Further analyses of the percentage volume data indicat-ed that re-population to the original percentage of Entomostrace was delayed until August in the experimental lakes. This delay is clearly shown in Figure XIV, even though the presence of certain other organisms, chiefly Trlarthra, Notholca, Bursarla and Stentor, made i t less, pronounced. A trend analysis of the Cyclops populations showed that they were not able to recover from the effects of the poisoning during the following summer. As an indirect effect of the poisoning, conditions in the following spring favoured a pulse of Trlarthra. No lethal effect of Fishtox on Rotifers or Protozoans could be ascertained. Any indirect effect of Fishtox on the dominant species in these Classes was unpredictable. The effect of Fishtox on phytoplankton was not lethal. Apart from technical diff icul t ies , a quantitative comparison of the plankton collections preceding the poisoning, with those taken during the same period the following year, was impracticable for two reasons: 1..Becausetne summer pulse of Entomostrace had been delayed due to the poisoning, the two periods were not comparable. 2. In 1948, in Borgeson lake, D. longlspina was super-seded by D. pulex which is noted for its. spring and f a l l pulses (Brown, 1929). The collections were hardly compar-able because this species was not present in the plankton samples the year previously. The effect of the absence of fish on the plankters cannot be Judged because the experimental lakes were s t i l l suffering from the carry-over effects of the poisoning. 88 Certain l i t toral or pond species, however, were obtained in the plankton collections in 1948, which were not found in the limnetic waters before the fish were ki l led . After poisoning, Smith (1939) reports a decreased number of Hyalella azteca (knickerbockerl), possibly due to the action of rotenone. Smith (1940) states that large numbers of Chaoborus larvae were killed although living larvae were s t i l l present in the bottom and plankton samples. Meehean (1941) observed that Chaoborus larvae, aquatic earthworms, leeches and salamanders were ki l led . Vestal (1942) reported that dead dragon fly and damsel f ly nymphs and enormous numbers of dead leeches were seen. Brown and Ball (1942) recorded Chaoborus (Corethra) larvae dying as well as leeches, aeschnine dragon fly nymphs and tadpoles from the effects of the poisoning. On experimenting, they found that on suspending these animals in a wire cage at varying depths down to six feet in the lake that they were killed inside of 24 hours. Chlronomus larvae suspended likewise, lived for 48 hours. No significant quantitative results of the effect of Fishtox on bottom organisms can be determined from the limited samples taken. Corroborating the work of the above investigators, leeches were seriously affected. In addition, certain species of worms in the lake remained unaffected while a larger species in the outlet stream were k i l l e d . A certain percentage of Hyalella. Chlronomus and Aeschna nymphs were also found dead as a result of the poisoning. 89 Probably because of their paucity, no Chaoborus larvae were noted. Brown and Ball (1942) noticed that tadpoles were extremely numerous after poisoning and attributed this to the removal of predatory f ish . In Dry lake, tadpoles were likewise numerous. As was pointed out earlier, an increase in the abundance of species of shore types in the experimental lakes, numerous beetle adults and larvae, backswimmers, water boatmen and amphlpods could be seen actively swimming about. One Hyalella in Dry lake was collected in a plankton collection. In contrast, none of these organisms were seen in the control lakes unless they were in very sheltered waters. Since minnows and sculpins were seen in four or five Inches of water in the control lakes, this obvious abundance of organisms in the experimental lakes is attributed to the removal of predatory f ish . 90 G E N E R A L D I S C U S S I O N Rotenone is widely used in the north-western United States for the erradication of coarse f ish . This practise is a routine procedure not cri t ically studied and is claimed to improve trout fishing. The present investigation has shown that the situation is a more complicated study than the present practice indicates. The effects of poisoning on the invertebrate fauna of a lake are great and in many instances unpredictable. In order to evaluate these effects, a comprehensive survey of limnologlcal conditions is necessary. The use of control lakes and planned experiments is recommended i f intelligent action is to be taken. Since stratification inhibits the dispersion of rotenone and low temperatures affect its potency, the poisoning of eutrophic lakes in late summer is recommended. The termination of the equithermal plateau, when the mean temperature of a lake is s t i l l high, marks the best period for poisoning. This period should be determined individually for each lake. At this: time, the upper stratum of a lake has a deeper uniform temperature than at any other time during the summer. Temperature gradients are less extreme, and poison mixes more easily. Oxygen data show that stagnation of the bottom waters is greater at the end of the equithermal period than at the beginning. If the depth and temperature conditions of lakes are such that the poison has d i f f i c u l t y penetrating to the bottom, summer stagnation, when present would aid the poison in exterminating fish since the lack of oxygen would exclude fis h from the safety of the unpolsoned bottom bottom waters. Plankton crustaceans are markedly reduced by poisoning and therefore, i t is recommended that trout stocking should not take place until the following summer, especially in lakes which are poor in l i t t o r a l and bottom organisms. It is probable that fauna of poisoned lakes undergo four transitional stages in their recovery. 1. A lethal period immediately following the poisoning of f i s h in which most of the crustaceans and numerous other organisms are k i l l e d . 2. A post-poisoning period that i s dominated by organ-isms not affected by rotenone during which the crustacean populations and other organisms affected by the poison are slowly increasing in numbers. This period in the experimental lakes was over by the end of July, the year following the poisoning. 3. A productive period similar to that of barren lakes hat have no f i s h eating the food organisms. This is marked by an increased range and variety of pond types as well as a general increase in the number of organisms above the level of abundance found in the lakes prior to the poisoning. 4. A restoration period in which the stocked trout reduce the numbers of food organisms in the lake to their previous level of abundance. Fish which are stocked in the poisoned lakes during the third and fourth period are expected to have a greater growth rate and a smaller mortality rate than those stocked after the fourth period has ended. The question as to which species of fish is the most detrimental to Kamloops trout will not be answered by the experiment. Theoretically the kokanee has been singled out as the one species most likely to effect their livelihood. The following reasons for this statement are advanced. 1. The general anatomical features of the kokanee and trout are nearly identical so that each would have nearly equal chances of procuring the larger food organisms. Numerous writers have stated that species which are nearly alike compete with each other to the detriment of one. 2. Trout and kokanee are both limnetic species preferihg cold water and consequently are restricted to somewhat the same habitat and-the food organisms available in It. 3. Due to the nature of the kokanee g i l l rakers, they are able to strain out smaller plankters than the trout. It is possible that in this way the kokanee can crop off the larger plankters before they grow large enough for the 93 trout to eat. Moreover, i t is possible that Daphnia pulex which is one of the most important foods of Kamloops trout in Paul lake, B.C.(Rawson, 1934) were cropped off in the experimental lakes by kokanee before they could grow large enough to reproduce. It is probable that because of this, Daphnia pulex was not found in the plankton collections taken prior to the poisoning. 4. The poisoning showed that there were very large numbers of kokanee in the lakes. This was attributed to the fact that they are successful shore spawners and do not need spawning streams as are usually required by trout. 5. KG>kanee stomachs examined after the poisoning contained the remains of several small f i sh . The fact that some of the kokanee measured over 14 inches indicated that they might be a serious predator of young trout especially i f other food were scarce. In order to more fully understand the part played by the various species of coarse fish on the livelihood of Kamloops trout, i t is recommended that similar experiments be conducted in lakes having just one species In them, especially the kokanee. 94 S U M M A R Y As part of a major experiment in coarse fish studies, a comparative ecological study was made of five interior lakes in British Columbia. The areas of these lakes varied between 16 and 175 acres, the maximum depths, between 36 and 128 feet and the length of shoreline, between 1.1 and 3.3 miles. Their proximity to each other minimized climatic variations. In 1947, highest mean temperatures varied between 13.3 and 16.6°C for the four lower lakes, in 1948, between.11.0 and 14.7° for a l l five lakes. Except for the lowest lake which may be of the third order, these lakes were classified as temperate lakes of the second order. During the summer stagnation period, the dissolved oxygen at the bottom of the lakes was poor, certain lakes having none. The hydrogen iron concentration showed l i t t l e variation being not less than 7.3 at the bottom or greater than 8.3 at the surface for any of the lakes. The flora and fauna of these lakes Included pond as well as limnetic types. A l l the lakes had., the same dominant plankters and bottom organisms. The fish fauna was composed of nine species of which the kokanee, minnows and suckers were very abundant. The flora of the three lakes which had. stable water levels were dominated by emergent bulrushes and stonewarts and that of the remaining two lakes which had 95 fluctuating water levels were dominated by smartweeds. A laboratory experiment showed that a concentration of 0.5 p.p.m. of Fishtox was lethal to the crustaceans Daphnia Bosmina, Cyclops, nauplius, the rotifer, Notholca. and the amphipod, Gammarus. Fishtox killed these organisms more quickly at approximately 20°C than at 4°. On September 7, 1947, the fish population in Dry lake was killed with a concentration of 0.83 p.p.m. of Fishtox. On September 8, 1947, the fish population in Borgeson lake was similarly killed with a concentration of 0.76 p-.p.m. of Fishtox. The effect of Fishtox on certain organisms was determined by comparing those in the experimental lakes with those in the control lakes. Analyses of trend lines was inconclusive except in the case of the copepod, Cyclops, which was markedly reduced in 1948 as a direct effect of the poisoning and the rotifer, Triarthra, which had a large spring pulse as an indirect effect. A percentage volume analyses of the phytoplankton, protozoans, rotifers and entomostracans showed that the poisoning caused a direct decline in the crustaceans immediately following the poisoning. In 1948, the percent-age volumes of crustaceans did not return to its average prepoison level until August. Fishtox killed a certain number of leeches, ollgochaets, chironomids'i'1" amphlpods, and aeschnine dragonfly nymphs. An-:Increase "In the variety and numbers of shore organisms was observed in Dry and Borgeson lakes in the Summer 96 following the poisoning, as well as large schools of tadpoles in Dry lake. This apparent increase in shore organisms was attributed to the absence of predatory f i s h . In the f a l l of 1938 a l l five lakes were restocked with Kamloops trout. 97 C C O N C : L U'S I O N s 1. The m o r p h o m e t r i c a l , p h y s i c a l , c h e m i c a l , and b i o l o g i c a l c h a r a c t e r i s t i c s o f the c o n t r o l and e x p e r i m e n t a l l a k e s a re comparable i n most r e s p e c t s . 2. F i s h t o x i s l e s s l e t h a l a t low tempe r a t u r e s t h a n a t h i g h t e m p e r a t u r e s . 3. F i s h t o x a p p l i e d i n the e a r l y f a l l k i l l s most o f the p l a n k t o n i c c r u s t a c e a n s . T h i s r e s u l t s i n the presence o f a v e r y low number o f c r u s t a c e a n s i n the s p r i n g a l o n g w i t h a consequent d e l a y I n the mid-summer p u l s e . 4. F i s h t o x k i l l s c e r t a i n numbers o f bottom organisms b u t n o t enough t o n o t i c e a b l y e f f e c t the abundance o f the s e organisms the f o l l o w i n g y e a r . 5» The i n c r e a s e d range o f c e r t a i n s p e c i e s , the appearance of new s p e c i e s and the a p p a r e n t i n c r e a s e d number o f c e r t a i n shore organisms obse r v e d the f o l l o w i n g y e a r a f t e r the p o i s o n i n g i n d i c a t e d a t r e n d towards the superabundance o f f i s h f o o d found i n b a r r e n l a k e s . » AA.P P E N D I X TABLE I . Comparative Morphometry of the One-Mile l a k e s 99 and. P a u l l a k e . A 4 ^ <y 4? J" < r ^ # ^ Maximum km. 0.8.2 1.12 1 .33 0 . 8 0 0 . 6 2 0.54 2 . 2 7 6 . 1 l e n g t h - (mi.) ( . 5 1 ) ( . 7 0 ) ( . 8 3 ) ( . 5 0 ) ( . 3 9 ) ( . 3 4 ) ( 1 . 4 l ) ( 3 . 8 ) Maximum km. . 115 .295 * . 3 4 5 . 2 8 7 . 6 0 0 .440 . 4 2 5 -74 w i d t h . (mi.) ( . 0 7 1 ) ( . 1 8 3 ) ( . 2 1 4 ) ( . 1 7 8 ) ( . 3 7 3 ) ( . 2 7 3 ) ( . 2 6 4 ) ( . 4 6 ) Mean km. .078 .275 .268 . 196 .242 .226 . 3 0 7 .64 w i d t h . (mi.) ( . 0 4 8 ) ( . 1 7 1 ) ( . 1 6 6 ) ( . 1 2 2 ) ( . 1 5 0 ) ( . 1 4 0 ) ( . 1 9 1 ) ( . 4 0 ) Maximum m. 1 1 .2 2 1 . 0 1 8 . 5 13-5 1 8 . 0 17 . 5 3 9 . 0 ^6 . 0 d e p t h . ( f t . ) ( 3 6 . 1 ) ( 6 8 . 9)(6O . 7)(44 . 3 ) ( 5 9 . 1 ) ( 5 7.40> ( 1 2 8 ) (184) Mean m. 6 . 0 1 0 . 2 7 . 3 7 . 9 9 . 8 1 1 . 4 14 . 9 3 4 . 2 d e p t h . ( f t . ) ( 1 9 . 7 ) ( 3 3 . 5 ) ( 2 4 . 0 ) ( 2 5 . 9 ) ( 3 2 . 2 ) ( 3 7 . 4 ) ( 4 8 . 9 ) ( 1 1 2 ) L n g t h of km. 1 . 8 0 2 . 5 5 3 . 6 5 2 . 0 5 I . 8 5 1 .50 5 . 3 5 1 3 . 4 3 s h o r e l i n e m i . ( l . 1 2 ) ( 1 . 5 8 ) ( 2 . 2 7 ) ( 1 . 2 7 ) ( 1 . 1 5 ) ( - 9 3 ) ( 3 . 3 2 ) ( 8 . 3 4 ) S h o r e l i n e development. 2 . 0 1 I . 3 0 1.72 1.46 1 .35 1 .21 1 .81 1.92 A r e a km.^ . 0 6 4 .308 .357 .157 .150 .122 .698 3 . 9 ( a c r e s ) ( l 6 ) ( 7 7 ) ( 8 9 ) ( 3 9 ) ( 3 7 . 5 ) ( 3 0 . 5 ) ( 1 7 5 ) (975) A r e a o f d e p t h ( 0 - 5 m . ) % of 10 • 37 50 32 1 3 29 6 t o t a l a r e a . Maximum d e p t h .044 .038 .031 . 0 3 4 .047 .051 .047 .028 - s u r f . r e l a t n . Volume km.3- . 0 0 0 3 9 . 0 0 3 1 4 . 0 0 2 6 3 . 0 0 1 2 5-00147.0 0 1 3 9 . 0 1 0 3 6 . 1 3 2 m i l l i o n s . f t . 3 ( 1 1 . 4 ) (111) (93) (44) (52) (49) (366) (4660) Volume development. 1 .61 1.46 1 .19 I . 8 3 I . 6 3 1 .96 1.14 1 .83 % Volume of e p i l i m n i o n ( 0 - 5m.) 68 40 52 54 38 38 29 14 ( 0 - 1 0 m . ) 99 67 78 93 70 70 51 2 7 . 5 ^Maximum w i d t h , over temporary s h a l l o w s a t s o u t h end, i s 455m. 100 TABLE I I . A r e a of Contour L i n e s , square meters M c C a f f e r t y L a i r d Dry Borgeson A l l i s o n Weed beds. 6 , 0 0 0 3 3 , 0 0 0 (Mean depth) (lm.) ( . 2 5 m . ) S u r f a c e , h i g h - w a t e r , 5 7 , 0 0 0 3 0 8 , 0 0 0 3 5 7 , 0 0 0 1 1 7 , 0 0 0 6 9 8 , 0 0 0 e x c l u s i v e of weed beds. S u r f a c e , low-water. 1 5 7 , 0 0 0 5m. c o n t o u r . 4 5 , 0 0 0 1 9 4 , 0 0 0 114 , 0 0 0 1 0 3 , 0 0 0 4 9 6 , 0 0 0 8m. c o n t o u r . 1 1 , 0 0 0 10m. c o n t o u r . 7 , 0 0 0 1 6 0 , 0 0 0 84 , 0 0 0 8 6 , 0 0 0 4 5 4 , 0 0 0 15m. c o n t o u r . ' 1 2 0 , 0 0 0 6 5 , 0 0 0 3 8 0 , 0 0 0 18m. c o n t o u r 3 4 , 0 0 0 20m. c o n t o u r . 2 3 , 0 0 0 2 2 5 , 0 0 0 25m. c o n t o u r . 1 5 1 , 0 0 0 30m. c o n t o u r . 8 1 , 0 0 0 101 TABLE III. Volume of depth zones. McCafferty Laird Dry Borgeson Allison Weed beds, m.-5 6,000 8,000 % 1.56 .54 High water m.3 1,378,000 to low water % (HW)52.46 0-5 meters m. 5 254,000 1,244,000 673,000 558,000 2,968,000 minus weed % 65-97 39-57 (HW)25-64 37-45 ' 28.64 beds. (LW)53-93 5-10 m. m. 5 871,000 491,000 471,000 2,374,000 % 27-70 (HW)18.71 32.04 22.91 (LW)39-35 5-11-2 m. m.3 125,000 375,000 % 32.47 25.54 10-13 m. m. 5 84,000 % (HW) 3.19 (LW) 6.72 10-15 m. m. 5 698,000 2,081,000 % 22.20 20.08 15-18 m. m. 5 65,000 163,000 % 4.42 1.57 15-20 m. m.3 1,312,000 "• • T:i2;66 15-20.5 m. m. 5 332,000 % 10.55 20-25 m. m. 5 932,000 % 8.99 25-30 m. m. 5 343,000 % 3.31 30-39 m. m. 3 190,000 % 1.83 Total m.^  (HW) volumes. 385,000 3,145,000 2,626,000 1,469,000 10,363,000 (LW) 1,248,000 102 TABLE IV. Temperature observations, i n degrees centugrade, for McCafferty lake. Summer temperatures, 1947 . Depth, Sta. A Sta. B Sta. A Sta. A meters. Ju l 25 J u l 31 Aug 11 Aug 16 0 . 5 17.9 19.0 16.6 16 .5 1 .5 17.8 17.8 16 .5 16.6 2.R 17-5 17 .3 16 .5 16.7 3 . 5 17.6 17 .3 16 .3 16 .5 4 . 5 17 .5 17.0 16.4 16 .5 5 . 5 17.2 16.8 16.3 16 .3 6 .5 16.7 16.0 16 .3 16 .3 7 . 5 14.8 15-4 16.0 16.0 8 . 5 13 .6 13.9 14.0 15-3 9 .5 13-5 12.9 1 3 . 3 13.1 10 .5 12.0 12.4 12 .5 Summer t e m p e r a t u r e s , 1948. S t a t i o n A Depth, meters; May 9 Jun 1 J u l 5 J u l 15 J u l 25 Aug 61 Aug.17 Sep 3 Oct 9 0 8 . 5 • 1 2 3 4 8.4 5 8 . 3 6 7 7 . 0 9 10 11 5 . 9 1 5 . 9 15.0 16. 5 16.0 15.6 15.6 14.5 8 . 9 1 4 . 5 15.1 16. 0 16.1 15.6 15.6 14.5 8 . 8 1 3 . 7 15.2 1 5 . 6 16.0 1 5 . 6 15-3 14.5 1 3 . 1 15.2 12.4 15.1 14. 8 1 5 . 7 15.5 15.1 14.5 8 . 7 14.6 10.2 14.4 1 5 . 3 7 . 8 13.1 14 .3 1 0 . 5 9 . 4 10.1 11/1 12 .5 8.-7 9.6 7.1 8.2 8 . 4 8 . 9 9 . 4 9.6 10.6 8 . 7 103 TABLE ,V_. . Temperature o b s e r v a t i o n s , i n degrees c e n t i g r a d e , f o r L a i r d l a k e . Summer t e m p e r a t u r e s , 1947. S'ta . -A Sta.B Sta•• A' .S*sc,B Depth, j u i 22 Aug 1 Aug 12 Aug 22 TT] P I" f* Q 0 . 5 ' 1 9 . 1 1 8 . 2 1 6 . 7 15-9 1 .5 1 8 . 3 1 8 . 0 1 6 . 6 1 5 . 8 2 . 5 1 7 . 7 1 7 . 5 16 . 6 1 5 . 6 3 . 5 17 .2 1 6 . 6 1 5 . 6 4 . 5 1 6 . 9 16 . 6 1 6 . 2 1 5 . 6 5 . 5 16 . 7 1 5 . 8 1 5 . 6 1 5 . 3 6 . 5 1 5 . 7 1 5 . 1 14 . 6 14 . 8 7 . 5 1 3 . 9 14 . 2 14 . 3 1 3 . 5 8 . 5 1 2 . 6 1 3 . 2 1 3 . 3 1 3 . 3 9 . 5 1 2 . 0 11 .7 1 2 . 5 1 2 . 4 1 0 . 5 1 0 . 9 1 1 . 4 11 .8 11 .6 1 1 . 5 1 0 . 2 1 1 . 4 1 2 . 3 1 1 . 5 1 2 . 5 1 1 . 0 11 .3 1 1 . 4 1 3 . 5 9 . 3 1 0 . 0 1 0 . 6 1 0 . 0 1 4 . 5 9 . 7 9 . 0 1 0 . 2 9 . 9 1 5 . 5 1 0 . 2 1 0 . 4 9 . 4 9 . 2 1 6 . 5 1 0 . 4 9 . 2 9 . 8 9 . 0 1 7 . 5 9 . 3 9 . 1 9 . 1 8 . 5 1 8 . 5 8 . 9 8 . 6 8 . 4 8 . 5 1 9 . 5 8 . 6 7 . 8 8 . 3 2 0 . 5 6 . 7 7 . 6 Summer t e m p e r a t u r e s , 1948. -%'ta'fion B 10.0 1 0 . 0 'Depth, May 9 Jun 1 J u l 6 J u l 16 J u l 25 Aug 8 Sep' 4 met e r s . 0 8.9 15.7 15.4 18 . 2 1 6 . 6 1 5 . 0 14 . 2 1 14.4 15.1 1 7 . 0 I 6 . 3 1 5 . 0 14.1 2 -z 8.8 1 3 . 7 14 . 9 15.4 1 5 . 8 14 . 9 14 . 1 J 4 8.6 1 2 . 5 14 . 7 14.6 14.5 14 . 2 1 3 . 9 5 6 11-5 13.8 7 8 8 . 0 9 . 9 11 . 0 9.6 10.4 1 0 . 5 1 1 . 0 9 10 10.8 11 12 7.4 • 8 . 0 8 . 7 7.4 8 . 3 9.1 9 . 2 13 14 8.6 15 7 . 9 16 6 . 3 6.7 8 . 3 7 . 0 7 . 2 8.9 17 18 7.6 7 . 5 19 7 . 0 20 5 . 3 6 . 9 6.8 6 . 9 7.1 21 6 . 2 9 . 9 8 . 4 7 . 9 104 TABLE 'SJ/I. Temperature o b s e r v a t i o n s , i n degrees c e n t i g r a d e , > of Dry l a k e . Summer t e m p e r a t u r e s , 1947. Depth, §Ca-*A Sta !.B St :a .A. Sta'.3 : meters. J u l 26 Aug 4 Aug 12 Aug 26 0 . 5 17.2 18.7 17.2 16.8 1 . 5 17 . 3 18.6 17.1 16.4 2 . 5 17 . 3 18.4 16.9 16.2 3 . 5 17.1 17.4 16.8 • 16.1 4 . 5 14.9 15-7 16.1 15.0 5 . 5 12 .7 12.6 14.1 14 . 3 6 . 5 12.2 9.2 11.1 11 . 5 7 . 5 8.4 7.8 8.8 8.7 8 . 5 6.0 7 . 5 8.0 8.7 9 . 5 7.6 7.4 7.4 7.9 10.9 7.1 6.8 6 . 5 6.7 11 . 5 6.1 6.8 6.6 6 . 5 12 . 5 5-1 6.1 8.2 5-9 1 3 . 5 5.4 6.1 5-3 14 . 5 6.4 Summer t e m p e r a t u r e s , 1948.StafFori / vB' ; • Depth, .'May 10 Jun 1 J u l 5 J u l 15 J u l 25 Aug 7 Sep 3 Oct 9 meters. 0 6.9 .15.1 14.9 17.8 16.7 15 . 5 1 5 . 3 1 14.1 14.9 1 7 . 5 16.6 15-5 1 5 . 2 2 6.9 13.4 14.4 13.9 15-8 15.4 1 5 . 2 3 13-4 4 10.4 10.8 10 . 1 1 2 . 3 14.8 14 . 2 5 6 6 . 3 9.0 10.0 7 8 8 . 7 8.4 7-7 8.4 8 . 2 8 . 2 9 7.6 10 6.0 11 12 7.6 6.4 6 . 7 6 . 5 6 . 5 13 7 . 2 14 6 . 1 15 6 . 7 16 6 . 5 6 . 2 6 . 2 17 6.9 6 . 2 17. 5 6.0 18 6.6 18. 5 6.0 6.1 105 TABLE V I I Temperature o b s e r v a t i o n s , i n degrees c e n t i g r a d e , f o r Borgeson l a k e . Summer t e m p e r a t u r e s , 194-7. S t s d o n A Depth, m e t e r s . J u l 27 Aug 8 Aug 13 Aug 27 0 . 5 1 7 . 8 18.5 17 .4 1 6 . 9 1 .5 1 7 . 9 1 8 . 5 1 7 . 3 1 6 . 9 2 . 5 17 .7 18.4 1 7 . 3 1 6 . 8 3.5 1 7 . 8 18 .4 1 7 . 3 I 6 . 7 4.5 17.6 1 8 . 2 1 7 . 2 1 6 . 6 5-5 16.3 I 6 . 3 1 6 . 7 1 6 . 3 6 . 5 14.7 14.7 1 5 . 1 15 .4 7 - 5 14.6 14.3 14.1 14.7 8 . 5 1 3 . 5 1 3 . 9 1 3 . 2 13.8 9 . 5 1 3 . 1 11.4 12 .4 1 3 . 3 1 0 . 5 1 2 . 6 11.4 11 .4 1 2 . 8 1 1 . 5 11 .3 1 0 . 5 11 .7 1 1 . 8 12 .5 10 .4 9 . 0 9 . 7 1 0 . 9 1 3 . 5 8 . 7 9 . 3 9.3 1 0 . 2 14.5 7-7 7.8 9 . 0 9 .4 15-5 8 . 9 8 . 3 8 . 1 8 .4 1 6 . 5 6 . 7 8 .4 6 . 8 7..5 1 7 . 5 8.3 6.3 8 .4 7 . 0 18.0 7.3 Summer t e m p e r a t u r e s , 1948 S t a t i o n A Depth, meters. May 10 May 31 Jul 6 Jul 16 Jul 26 Aug 7 Sep 4 Oct 9 0 9 . 5 17.4 14.3" 18.3 1 5 . 7 14.5 13.6 10.0 1 1 6 . 7 14.4 1 5 . 9 15 .4 14.5 13 .6 2 9 . 3 1 5 . 3 13 .4 1 2 . 5 13.3 14.5 13 .6 ' 3 1 5 . 0 4 1 3 . 0 11.5 1 1 . 0 11.6 1 2 . 1 1 2 . 5 5 11.6 1 0 . 9 /~ 0 8.8 11 .2 10 .4 7 8 8.7 1 0 . 3 9 . 5 9-9 1 0 . 3 10.8 9 . 9 9 10 7.1 7.8 9 . 2 11 12 6.6 8.1 7.8 8.4 8.9 9 . 6 13 9 . 9 14 5.7 7.6 15 6.3 16 5.8 5.6 5.8 5 . 9 7 .0 7.9 1 6 . 5 5.7 6.2 17 4.9 5-5 5.7 5.8 1 0 6 TABLE V I I I Temperature o b s e r v a t i o n s , i n degrees c e n t i g r a d e , of A l l i s o n l a k e . Summer t e m p e r a t u r e s , 1948. S t a t i o n A Depth, 2030 h r s . meters. May 10 Jun 1 J u l 7 J u l 17 J u l 27 Aug 9 Sep 5 Oct 9 10.0 0 7.0 18.6 18.3- 19.4 17.2 17.0 14.2 1 16.0 1 5 . 9 18.6 17.5 16.6 14.0 2 6.9 14.1 15.8 17.4 17.3 16.6 14.0 3 13.9 16.4 4 15.5 15.7> 17.0 I 6 . 3 14.0 5 15.8-6 6.8 12.1 15.3 6. 5 14.0 1 7 1 3 . 0 14.0 7. 12 .0 8 10.2- 9.9: 9.9 11.4 13.4 8. 5 10.8-9 10.5 11.7 9. 5 11.4 10 6.6 8.8 9.8 10.5 11 9.7 12 . 8.7 7.9 8.6 9.0 8.7 13 8.4 14 5-9 8.6 7.6 7.6 15 16 7.5 6.0 7.3 6.8 7-0 17 18 5.1 6.7 6.1 19' 5.8 20 7.0 5.4 5-5 5.8 22 • 4.9 24 25 6.0 5.4 5.6 26 4.7 29 4.9 30 7.6 5.0 5.3 35 5.3 .4.8 4.9 5.1 36 . 5.1 37 4.9 39 5.1 9.6 6.9 6.1 5.5 5.2 10? TABLE XXV Highest summe: f o r One-Mile * S u r f a c e Bottom Mean Mc C a f f e r t y 19.0 12.5 16.6 L a i r d 19.1 8.3 13.3 Dry (L.W.) 18.7 6.1 13-3 Borgeson 18.5 7.0 14.0 • temperatures l a k e s , 1947. Summer Mean of Mean of heat incomes 0-10 m. 0-5 m. g r . c a l . / cm. 16.6 17.6 7,560 15.0 17.75 9,486 13.8 16.9 7,347 16.0 18.05 9,800 Highest summer temperatures f o r One-Miles l a k e s , 1948. Summer Surface Bottom Mean Mean of 0-10 m. Mean of 0-5 m. heat i n c gr. c a l . M c C a f f e r t y 16.5 10.6 14.7 14.7 15.8 6,420 L a i r d 18.2 7.9 11.5 13.2 15.95 7,650 Dry (H.W.) 17.8 6.7 11.4 12.8 15.05 5,400 Borgeson 18.3 7.3 11.0 12.0 13.5 6,860 A l l i s o n 19.4 5.2 11.0 14.7 17.1 10,430 Summer temperatures f o r Paul l a k e , August 22, 1931. Summer Mean of Mean of heat income Surf a c e Bottom Mean 0-10 m. 0-5 m. gr. c a l . / cm. Paul 20.2 4.8 9.4 17.7 18,500 * F o r 1947, s u r f a c e temperatures are g i v e n f o r .5m« below the s u r f a c e . 1947 TABLE X. Mean temperatures for 1947 and 1948, IQQ degrees centigrade. McCafferty Laird Dry Borgeson Allison July 22 13-26 " 25 16.64 " 26 12.44 " 2 7 13.97 July 31 16.58 Aug. 1 13.09 tf 4 13.31 " 8 13.93 Aug. 11 15.92 " 12 12.91 12.98 " 13 13-78 Aug. 16 16.05 " 22 12.48 " 26 12.73 " 27 13.97 1948 May 9 8.04 7.50 " 10 6.40 7.86 6.24 May 31 10.29 June 1 12.05 10.13 10.33 July 5 13-97 10.59 " 6 11.45 10.41 it 10.69 July 15 14.11 10.37 " 16 11.22 10.16 " 17 10.46 July 25 14.67 11.17 11.14 " 26 10.44 " 27 10.91 Aug. 6 14.52 * 7 11.42 10.81 " 8 11.15 " 9 10.97 Aug. 17 14.44 Sep. 3 14.07 11.28 11 4 11.04 11.01 5 10.43 Oct. 9 8.74 9.18 8.70 9.74 8.76 TABLE XI 109 Mid-Summer Oxygen conditions in McCafferty lake for 1947. Depth in Temp. 1 Per cent of Dates meters in °C. 0 2 °2 D saturation July 25 Surface 17.9 8.26 8.53 -.27 95 0.5 17.9 8.26 8.53 -.27 95 3.5 17.6 7.96 8.58 -.62 92 6.5 16.7 8.41 8.76 -.35 95 9-5 13.5 9.75 9.40 A 3 5 103 July 31 0.5 19.0 8.26 8.40 -.14 98 4.5 17.0 8.26 8.70 -.44 94 9.5 12.9 8.26 9.53 -1.27 85 Aug. 11 0.5 16.6 8.47 8.78 -.31 95 4.5 16.4 8.43 8.82 -.39 95 9.5 13-3 9.16 9.44 -.28 96 Aug. 16 0.5 16.5 8.86 8.80 /.06 100 4.5 16.5 8.76 8.80 -.04 99 9.5 13.1 7.87 9.48 -1.61 82 Mid-Summer Oxygen conditions in McCafferty lake for 1948. Depth in Temp, Per cent of Dates meters in 6<j. °2 o| D saturation July 25 1 16.1 8.23 8.87 -.64 92 3 15.9 8.32 8.92 -.60 93 6 15.3 8.32 9.04 -.72 92 10 8.9 5.77 10.44 -4.67 54 Aug. 6 0 15.6 8.18 8.98 -.80 90 3 15.6 8.25 8.93 -.73 91 6 15.3 8.25 9.04 -.79 90 10 9.4 4.83 10.31 -5-48 46 Aug. 17 o' 15.6 7.92 8.98 -1.06 92 3 15.2 7.62 9.06 -1.44 83 6 14.3 7.20 9-24 -2.04 77 10 9.6 1.30 10.46 -9.16 12 Sept. 3 0 14.5 8.30 9.20 -.90 90 4 14.5 8.28 9.20 -.92 89 7 14.3 8.05 9.24 -1.19 87 10 10.6 2.42 10.00 -7.58 24 Op represents the actual oxygen present in the lake. 0 £ represents the oxygen required to saturate the water at the observed temperature. D represents the deficiency or excess of oxygen at various depths. TABLE XII 110 Mid-Summer Oxygen conditions In Laird lake for 194-7. Depth in Temp. Per cent of Dates meters in 6 C . °2 °l D saturation July 22 0.5 19.1 7.96 8.38 -.42 95 6.5 15.7 8.41 8.96 -.55 93 13.5 9.3 8.63 10.34 -1.71 83 19.5 8.6 7.29 10.52 -3.23 68 20.5 6.7 6.32 11.02 -4.70 57 Aug. 1 0.5 18.2 7.90 8.48 -.58 92 7.5 14.2 11.18 9.26 /1.92 120 14.5 9.0 8.40 10.41 -2.01 80 20.5 7.6 2.63 10.79 -8.16 24 Aug. 12 0.5 16.7 8.60 8.76 -.16 97.5 5.5 15.6 8.73 8.98 -.25 96 11.5 12.3 8.70 9.65 -.95 90 17.5 9-1 7.13 10.39 -3.26 68 Aug. 22 0.5 15-9 8.52 8.92 -.40 95 6.5 14.8 8.52 9-14 -.62 93 13.5 10.0 8.28 10.16 -1.88 80 19.5 8.3 3-78 10.60 -6.82 34 Mid-! Summer Oxygen conditions in Laird lake for 1948. Depth in Temp. n Per cent of Dates meters in 6 C . °2 °2 D saturation July 25 0 16.6 9.10 8.78 /.32 102 8 10.4 9.52 10.06 -.54 94 16 7.2 7.42 10.89 -3.47 67 20 6.9 5.72 10.96 -5.24 51 Aug. 8 8 10.5 7.48 10.04 -2.56 73 16 8.9 7.78 10.44 -2.66 74 20 7.1 3.51 10.92 -7.41 31.5 Sept. 4 0 14.2 8.30 9.24 -.94 90 12 9.2 8.19 10.36 -2.17 78 15 7-9 7.46 10.70 -3.24 69 18 7.5 4.15 10.81 -6.66 38 TABLE XIII 111 Mid-Summer Oxygen conditions in Dry lake for 1947. Dates Depth in meters Temp, in °C. °2 °\ D Per cent of saturation July 26 0.5 4.5 9.5 13.5 17.2 14.9 7.6 5.4 9.23 10.53 3.24 0.19 8.67 9.13 10.79 11.39 /.56 /1.40 -7.55 -11.20 105 114 30 1.4 Aug. 4 0.5 4.5 9.5 13-5 18.7 15-7 7.4 6.1 8.77 10.28 1.96 0.17 8.43 8.96 10.83 11.17 /.34 /1.32 -8.87 -11.00 103 114 18 Aug. 12 0.5 4.5 8.5 11.5 17.2 16.1 8.0 6.6 9.23 9.69 3.19 O.20 8.67 8.87 10.68 11.04 /•56 /.82 -7.49 -10.84 105 108 29 1.6 Aug. 26 0.5 4.5 9.5 13-5 16.8 15-0 7.9 5.3 9.54 9.60 1.45 .035 8.74 9.10 10.70 11.42 /.80 /.50 -9.25 -11.33 107 105 . 13.2 '•75 (Aug. 4 Spring water 6.19 p.p. m.) Mid- Summer Oxygen conditions in Dry lake for 1948. Dates Depth in meters Temp, in 6 C . °2 D Per cent of saturation July 25 0 8 12 17.5 16.7 8.4 6.7 6.0 7.99 8.93 5.72 2.42 8.76 10.57 11.02 11£20 -.77 -1.64 -5.30 -8.78 90 84 51 21 Aug. 7 0 8 12 17 15.5 8.2 6.5 6.2 8.18 8.03 4.66 2.60 9.00 10.62 11.06 11.14 -.82 -2.59 -6.40 -8.54 90 75 41.5 23 Sept. 3 0 8 12 16.5 15.3 8.2 6.5 6.2 9.23 6.70 3.15 0.32 9.04 10.62 11.06 11.14 A19 -3.92 -7.91 -10.82 101.5 62.5 28 2.5 TABLE XIV 112 Mid-Summer Oxygen conditions in Borgeson lake for 1947. Depth in Temp. Per cent of Dates meters in 6 C . °2 °1 D saturation July 27 0.5 17.8 8.78 8.54 /.24 103 5.5 16.3 11.53 8.84 /2.69 130 11.5 11.3 10.97 9.86 / l . l l 110 17.5 8.3 0 10.60 -10.60 0 Aug. 8 0.5 18.5 8.08 8.45 -.37 95 5.5 16.3 11.97 8.84 /3.13 135 11.5 10.5 10.80 10.04 A 76 106 16.5 8.4 0 10.57 -10.57 0 Aug. 13 0.5 17-4 9.39 8.62 /.77 107 5-5 16.7 10.82 8.76 /2.06 123 11.5 10.5 10.69 10.04 /.65 107 16.5 6.7 0 11.00 -11.00 0 Aug. 27 0.5 16.9 9.43 8.73 /•70 107 5-5 16.3 10.00 8.84 /1.16 112 11.5 11.8 9.29 9.76 -.,47 94 16.5 7-5 0 10.82 -10.82 0 Mid-Summer Oxygen conditions in Borgeson lake for 1948. Depth in Tercnjp n Per cent of Dates meters $m r§ • • o 2 °2 D saturation July 26 0 15.7 8.63 8.96 -.33 95.5 8 9.9 7.99 10.19 -2.20 78 16 5-9 0 11.24 -11.24 0 17 5.8 0 11.26 -11.26 0 Aug. 7 0 14.5 8.88 9.20 -.32 95.5 8 10.3 8.18 10.08 -1.90 80.5 12 8.9 5-39 10.44 -5.05 51 16.5 6.2 0 11.14 -11.14 0 Sept. 4 0 13.6 8.08 9.38 -1.30 85 8 10.8 6.32 9.96 -3.64 64 12 9.6 3.79 10.26 -6.47 35 16 7.0 0 10.93 -10.93 0 TABLE XV 113 Mid-Summer Oxygen conditions in Allison lake for 1948. Dates Depth in Temp, meters in °C. Per cent of saturation July 27 20;30 hrs. Aug. 9 09:50 hrs. 0 17.2 9.20 8.67 /.53 106 4 17.0 9-37 8.70 / . 6 7 lo7 16 7.3 7.08 10.86 -3.78 65.5 29 4.9 .21 11.54 -11.33 1.5 0 17.0 9.08 8.70 /•38 104 4 16.3 8.99 8.84 A15 102 6 15-3 10.7 9.04 /1.66 118.5 6.5 14.0 11.0 9-30 /1.70 118.5 7 13-0 11.1 9.50 /1.60 117 7.5 12.0 11.5 9.71 /1.79 118.5 8 11.4 12.1 9.83 /2.27 123 9 10.5 11.0 10.04 /.96 109 12 9.0 10.4 10.41 -.01 100 16 6.8 5.6 11.00 -5.40 51 25 5.4 0.41 11.39 -10.98 3 33 5.0 0 11.50 -11.50 0 Aug. 26 14:45 hrs. 0 14.2 8.55 9.26 -.71 92 7 14.0 9.10 9.30 - . 2 0 98 9 11.7 10.2 9.77 / . 4 3 104 9.5 11.4 10.5 9.83 / . 6 7 107 10 10.5 10.10 10.04 /.06 101 11 9.7 9.50 10.24 - . 7 4 93 12 8.7 8.55 10.50 -1.95 82 14 7.6 7.50 10.79 -3.29 70 16 7.0 4.60 10.93 -6.33 42 18 6.1 2.62 11.17 -8.55 23 20 5.8 1.29 11.26 -9.97 11 30 5-3 (trace) 11.42 -11.42 0 TABLE XVI Hydrogen-ion concentration of the One-Mile lakes. McCafferty lake Laird lake Depth meters 5 Sept. 1947 3 Sept. 1948 5 Sept. 1947 4 Sept. 1948 0 8.0 7.9 7.8 7.8 2 7.9 ' 7.8 4 7-9 7.8 7 7.9 8 7.8 10 7.8 12 7.8 15 7.8 18 7.7 Dry lake Borgeson lake Depth meters 5 Sept. 1947 3 Sept. 1948 5 Sept. 1947 4 Sept. 1948 0 7.8 7.9 8.1 7.8 2 7.9 7.8 4 7.9 7.8 8 7.8 7.8 12 7.8 7.8 16 16.5 7.8 7.6 Allison lake Depth meters 13 Sept. 1947 27 July 1948 9 Aug. 1948 5 Sept. 1948 0 8.3 8.2 8.3 7.7 2 8.2 7-7 4 8.2 8.3 6 8.2 7 8.2 7.7 8 8.2 8.1 9 8.1 10 7.7 11 7.7 12 7.9 12.5 7.5 14 7.5 16 8.0 7.6 7.4 18 7.4 20 7 . 3 25 7.3 29 7.4 3 0 7.3 33 7.3 35 7.4 39 7.3 TABLE XVII 115 F L O R A Species McCafferty Laird Dry Borgeson Allisc MYXOPHYCEAE Gomphosphaeria sp. X X Clathrocystis sp. X Oscillatoria sp. X Nostoc sp. X Anabaena sp. X X X X X Coelospharium sp. X X X Microcystis sp. X X X Filamentous sp. X X BAC CILLARIEAE Cyclotella sp. X X X X X Stephanodiscus sp. X Pleurosigma sp. X Pinnularia sp. X X X X Navicula sp. R X Amphora sp. X X X X Cocconema sp. X Surirella sp. X X Synedra sp. X X X X X Fragillarla sp. X X X X X Asterionella sp. X X X X X Tabellaria sp. X X X X X Dlatoma sp. X X X X X Closterium sp. X X CHLOROPHYCEAE Docidium sp. X X X Staurastrum sp. X X X Cosmarium sp. X Arthrodesmus sp. X X X Xanthidium sp. X Sphaerocystis sp. X Pleurococcus sp. X Pedlastrum sp. X X X Melosiro sp. X (Carl "36) Spirogyra sp. X Mougeotla sp. X (Carl '36) Ulothrix sp. X (Carl '36) Filamentous X X X X X (several sp.) TABLE XVII (cont'd) - 2 -116 F L O R A Species McCafferty Laird Dry Borgeson Allison CHARACEAE Chara fragilis Derv . X X X X X RHODOPHYCBAE Batrachosperimjrm sp. X MONOCOTYLEDONEAE Typha la t i fo l ia L. X X X . Sparganium sp. X X Potemogeton flliformis X X X X X Pers. Potemogeton sp. X X X X X DICOTYLEDONEAE Carex sp. X Scirpus sp. X X X Nymphaea polysepala X X Hlppuris vulgaris X X X Myriophyllum sp. X X X X Utricularia sp. X X X Callitriche sp. X Polygonum sp.. X X X X X Ranunculus X X trichophyllus Chaix TABLE XVIII 117 F A U N A Species PROTOZOA Difflugia sp. Uroglena sp. Dynobryon sp. Peridlnium sp. Ceratium sp. Bursaria sp. Stentor sp. Stombidium sp. Sphenoderia sp. TURBELLARIA Planaria foremanii (girard) PORIFERA Spongilla sp. CESTOIDEA Unidentified 2 sp. NEMATHELMINTHES Unidentified sp. BRYOZOA Plumatella polymorpha (Carl '36) GASTROPODA Physa sp. Lymnaea sp. Planorbidae (several sp.) Valvata lewisi (Carl »36) Cochliopa (Carl '36) Gyraulus vermicularis (Carl '36) PELECYPODA Anodonta sp. PIsidium sp. Musculium truncatum (Carl '36) McCaf- Laird Dry Bor- A l l i -ferty geson son 47 •48 •47 •48 '47 '48 '47 '48 •4c" R P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P B B B B B S B B S S S S S S S R B B B B B R R R B B B B R B B B B B B B B B B B B B B B B B B B B B B TABLE XVIII (cont'd) 118 F A U N A Species McCaf- Laird Dry Bpr- A l l l -ferty geson son 1 47 •48 '47 •48 '47 '48 '47 '48 '48 OLIGOCHAETA Stylaria lacustris B B B B B (Linnaeus) Nais sp. B B B B B Lumbricus (Carl '36) R Unidentified sp. B B B B B B B HIRUDINEA Glossiphonia stagnalis B B B B B (Linnaeus) Glossiphonia complanata. B B B B B (Linnaeus) Glossiphonia heteroclita B (Linnaeus) Plscicola punctata B B B B (Virr i l l ) Herpobdella punctata B B (Leidy) Unidentified sp. S S ROTATORIA Polyarthra sp. P P P P P P P P P Synchaeta sp. P P P Keratella sp. 1 P P P P P P P P P Keratella sp. 2 P P P P P P Notholca sp. P P P P P P P ' P P Ploesoma sp. P P P P P P P Ploesoma hudsoni P P P P P P P P P Asplanchna sp. P P P P P P P P P Trlarthra sp. P P P P P P P P Conechilus sp. P P P P Unidentified P P P P P P P P P (several sp.) CLADOCERA Slda crystalllna B P&B B (Muller) Diaphanosoma brachyurum P P P (Meven) Daphnia pulex (de Geer) P P&B Daphnia longispina P P P P P P&B P P P (Muller) Daphnia dentifera Forbes P Simocephalus serrulatus (Koch) Scapholeberis mucromata B B B B S B (Muller) TABLE X V I I I ( c o n t ' d ) - 3 -F A U N A 1 1 9 S p e c i e s McCaf- L a i r d D ry B o r - A l l i -f e r t y g e son son •47 «48 '47 '48 '47 *48 '47 '48 '48 CLADOCERA ( c o n t ' d ) C e r i o d a p h n i a qua&rangula P P P P P P P P P ( M u l l e r ) Bosmina o b t u s i r o s t r i s P P P P P P P P Sars Bosmina l o n g i s p i n a R P L e y d i g ( C a r l ' 3 6 ) E u r y c e r c u s l a m e l l a t u s B B B B B ( M u l l e r ) Camptocercus r e c t i r o s t r i s B S h o e d l e r A c r o p e r u s harpae B a l r d R ( C a r l ' 3 6 ) L e y d l g i a q u a d r a n g u l a r i s R ( L e y d i g ) ( C a r l ' 3 6 ) A l o n a a f f i n i s ( L e y d i g ) R ( C a r l T 3 6 ) A l o n a c o s t a t a S a r s R ( C a r l ' 3 6 ) A l o n a r e c t a n g u l a Sars S A l o n a q u a d r a n g u l a r i s P ( M u l l e r ) A l o n e l l a e x c i s a P ( F i s c h e r ) G r a p t o l e b e r i s t e s t u d i n a r i a R ( F i s c h e r ) ( C a r l '40) P l e u r o x u s d e n t i c u l a t u s R B i r g e ( C a r l * 3 6 ) P l e u r o x u s sp. ( C a r l ' 3 6 ) R Chydorus s p h a e r i c u s R P P ( M u l l e r ) ( C a r l ' 3 6 ) L e p t o d o r a k i n d t i l R P P (Focke) ( C a r l ' 3 6 ) COPEPODA E p i s h u r a n e v a d ^ n s i s R L i l l j e b o r g ( C a r l ' 3 6 ) Diaptomus t y r e l l i Poppe P P P P P P P P Diaptomus a s h l a n d i Marsh R ( C a r l ' 3 6 ) C y c l o p s v i r i d i s J u r i n e P P P P P P P P C y c l o p s b l c u s p i d a t u s C l a u s P P P P P P P P Canthocamptus minutus R C l a u s ( C a r l ' 3 6 ) L e r n a e o p o d i d a e sp. R ( C a r l ' 3 6 ) t TABLE XVIII (cont'd) Species AMPHIOPODA G-ammarus limnaeus Smith Hyalella azteca Saussure OSTRACODA Several sp. (Carl '36) PLECOPTERA NYMPHS Perlinella sp. ODONATA NYMPHS Enallagma sp. Ischnura sp. Aeschna sp. Gynacantha sp. Cordulia sp. Nannothemis sp. Boyeria sp. Pachydiplax sp. EPHEMEROPTERA NYMPHS Habrophleboides sp. Ameletus sp. Caenis sp. Potamanthus sp. ParaleptoPhlebia Bp. Slphlonurus sp. HEMIPTERA Corixa sp. Gerris sp. Notonecta sp. (Carl '36) TRICHOPTERA LARVAE LlmnoPhilidae (several sp.) Triaenodes sp. Phryganea sp. Setodes sp. (Carl '36) Philopotamus sp. Hydropsyche sp. - 4 -F A U N A McCaf- Laird f erty Dry Bor-geson 120 A l l i -son •47 '48 '47 '48 '47 '48 '47 '48 *48 B B B B B B B B S B B B B R B B B B B B B B B B B B P&B B B B B B B B B B B B S B S S B S s s s B B B B B B B B B B B B B B B S S S B S B S S B B B TABLE XVIII (cont'd) Species F A U N A Laird McCaf-ferty Dry Bor-geson A l l i -son DIPTEPA LARVAE Chlronomldae (several sp.) Chaoborus sp. Culex sp. Cyclorhapha sp. Chrysops sp. Simulium sp. Tabanus sp. Euyparypus sp. Tlpula sp. COLEOPTERA Gyrlnidae sp. (adult) Amphizoa sp. (adult) Dytiscidae sp. (adult) Parnidae sp. (adult) Dascyllidae sp. (adult) Acilius sp. (larva) Halipus sp. (larva) Laccophilus sp. (larva) Hydroporus sp. (larva) NEUROPTERA LARVA Sialis sp. HYDRACARINA Several sp. TELEOSTEI Prosopium williamsoni (Girard). Oncorhynchus nerka kennerlyi (Suckley) Salmo gairdnerii kamloops 'Jordan.5 Salvelinus fontinalis (Mltchill) Catostomus macrocheilus Girard': Mylochellus caurinus (Richardson) •47 '48 '47 '48 '47 '48 '47 '48 '48 B B B B B B B B B B B B N N N N N N P&B B B B B B B P&B B B P&B S B B S S s s B B P&B B P&B B P&B P&B N N N N N N N N N N N N N N B S B P&B N N N N TABLE XVIII (cont'd) - 6 -F A U N A 122 Species McCaf- Laird Dry Bor- A l l i -ferty geson son '47 '48 '47 '48 '47 '48 '47 '48 '48 TELEOSTEI (cont'd) Ptychocheilus N N N N N oregonensis (Richardson) Richardsonius N . N N N N balteatus (Ricahrdson) Cottus rhotheus N N N N N (Rosa Smith) AMPHIBIA LARVAE Ambystoma tigrinum S slateri (Dunn) Bufo boreas boreas S (Baird and Glrard) B. Specimens obtained by means of a bottom dredge. N. Specimens obtained by means of g i l l or seine nets. P. Specimens obtained by means of plankton nets. R. Specimens cited in reference literature. S. Specimens obtained by means of dip nets. TABLE XIX 1 2 3 - Kamloops Trout and Speckled Char (eastern brook trout) stocking records for the One-Mile lakes Year McCafferty Laird Borgeson Allison 1928 10,000 E.B.T.* fry (Nelson) 1929 9,850 E.B.T.* 15,000 K.T. fry eyed-eggs 1930 20,000 E.B.T. eyed-eggs 1932 25,000 K.T. 25,000 K.T. eyed-eggs eyed-eggs 1934 20,000 K.T. fry 1936 5,000 K.T. 10,000 K.T.. 10,000 K.T. fry fry fry 1937 10,000 K.T. 10,000 K.T. 10,000 K.T. fry fry fry 1938 10,000 K.T. 10,000 K.T. 13,000 K.T. fry fry fry 1939 10,000 K.T. 10,000 K.T. 5,000 K.T. fry fry fry 1940 10,000 K.T. 5,000 K.T. fry fry 1942 20,000 K.T. 10,000 K.T. 5,000 K.T. fry (Penask) fry fry 1943 20,000 K.T.* 4,000 K.T. eggs (Penask) fry 1944 15,000 K.T.* eggs (Penask) 1945 15,000 K.T. fry (Penask) - ~ *One-Mile Creek Unless otherwise noted, fish stock by Summerland Hatchery TABLE XIX (cont'd) Kamloops Trout and Speckled Char (eastern brook trout) : stocking records for the One-Mile lakes Year 1948 McCafferty Laird Dry Borgeson Allison 850 K.T. 7700 K.T. 3400 K.T. 2150 K.T. 9000 K.T. fry fry fry fry fry 107 K.T. 963 K.T. 425 K.T. 269 K.~T. 1125 K.T. fingerlings fingerlings fingerlinga fingerlings fingerlings deft (right (right fright (right, pelvics pelvics pelvics pelvics pelvics removed) removed) removed) removed) removed) TABLE XX 125 Quantitative analysis of McCafferty lake plankton collections Total of three hauls Total of three hauls No. 20 plankton net No. 10 plankton net Centri Centri Depth Settled -fuge Dry wt. Settled -fuge of haul vol . in vol . in in vol . in vol . in cc. cc. gm. cc. cc. 25-7-47 10 -0m. 4.2 2.15 .096 " 10 -6m. 2.0 0.95 6 -Om. 4.2 2.5 31-7-47 10 -Om. 3 . 8 1.8 .092 10 -6m. 2.2 1.1 6 -Om. 3 . 3 2.0 11-8-47 10 -Om. 3 . 2 1.65 .070 10 -6m. 1.1 0.65 6 -Om. 2.9 1.8 16-8-47 10 -Om. 2.8 1.4 .057 II 10 -6m. 0.8 0.55 6 -Om. 2.5 1.40 1 3 - 9 - 4 7 10.5-0m. 1.9 0.85 .049 23-9-47 9 -Om. 1.4 0.7 .038 13-9-47 11 -Om. 4.1 2.4 23-9-47 9 -Om. 2.5 1.6 One haul No. 20 plankton net Depth of haul Settled vol . in cc. Centri -fuge vol . in cc. One haul No. 10 plankton net Centri Settled -fuge vol . in vol . in cc. cc. 9-5-48 10 -Om. 0.5 0.23 1.37 0.6 1-6-48 9 -Om. 0.95 0.5 2.4 1.1 5-7-48 9. 5-0m. 3.0 1.65 3.9 2.65 15-7-48 10 -Om. 1.85 0.92 5.7 2.8 25-7-48 10 -Om. 3.2 1.65 3.0 1.86 6-8-48 10 -Om. 2.18 0.93 3.4 1.7 17-8-48 10 -Om. 1.18 0.7 1.7 0.9 3-9-48 10 -Om. 1.28 0.77 1.75 0.95 9-10-48 10 -Om. 0.42 0.25 0.58 0.4 TABLE XXI 126 Quantitative analysis of Laird lake plankton collections Total of three hauls No. 20 plankton net Total of three hauls No. 10 plankton net Centri Centri Depth Settled -fuge Dry wt. Settled -fuge of haul vol.In vol . in in vol . in vol . in - cc. cc. era. cc. cc. 24-7-47 19 -Om. 4.0 1.65 .081 6 -Om. 2.4 0.80 13 -6m. 2.3 0.58 19-*13m. 2.05 0.62 1-8-47 20.5-Om.- 3-3 1.45 .065 7 -Om. 3.1 1.4 14 -7m. 1.9 O.58 20.5-l4m. 1.5 0.52 12-8-47 18 -Om. 1.8 0.75 .032 6 -Om. 1.4 0.63 12 -6m. 0.9 0.32 18 -12m. 1.0 0.34 25-8-47 20. -Om. 2.0 0.9 .040 7 -Om. 1.5 0.81 14 -7m. 0.64 0.23 20 -14m. 0.62 0.22 13-9-47 17.5-0m. 4.7 21.15 22-9-47 18 -Om. 4.9 2.52 One haul One haul No. 20 plankton net No. 10 plankton net Centri Centri Depth Settled -fuge Settled -fuge of haul vol . in vol . in vol . in vol . in cc. cc. cc. cc. 9-5-48 20 -Om. 0.63 0.32 1.5 0.77 1-6-48 21 -Om. 1.0 0.52 2.5 1.1 6-7-48 20 -Om-i 1.3 0.62 2.5 1.3 16-7-48 19 -Om. 1.4 0.66 2.4 1.1 26-7-48 19 -Om. 1.9 0.67 2.8 1.35 8-8-48 19 -Om. 1.85 0.68 2.1 1.12 4-9-48 19 -Om. 1.88 0.70 3.1 1.45 9-10-48 19 -Om. 1.22 0.40 2.20 1.12 TABLE XXII 127 Quantitative analysis of Dry lake plankton collections Total of three hauls Total of three hauls No. 20 plankton net No. 10 plankton net Centri Centri Depth Settled -fuge Dry wt Settled -fuge of haul vol.In vol . in in vol . in vol . in cc. cc. gm. cc. cc. 26-7-47 13 -Om. 8.5 4.1 .168 4 -Om. 3.15 1.55 8 -4m. 3.05 1.5 13 -8m. 4.2 2.05 4-8-47 14 -Om. 5.8 2.7 .124 4 -Om. 3.15 1.65 9 -4m. 2.30 1.10 14 -9m. 1.80 0.85 12-8-47 12 -Om. 5.7 2.3 .094 " 4 -Om. 3.15 1.2 II 8 -4m. 1.3 0.65 12 -8m. 2.6 0.98 ^26-8-47 14 -Om. 4.5 1.8 .072 5 -Om. 4.2 1.85 9 -5m. 1.6 0.67 14 -9m. 2.2 0.75 12-9-47 13 -Om. 1.4 0.5 .025 19-9-47 13 -Om. 1.1 0.3 .023 12-9-47 13 -Om. 2.0 0.8 19-9-47 13 -Om. 0.85 0.39 One haul One haul No. 20 planktbn net No. 10 plankton net Centri Centri Depth Settled -fuge Settled -fuge of haul vol . in vol . in vol . in vol . in cc. cc. cc. cc. 10-5-48 13.5-Om. 0.3 0.1 0.5 0.15 31-5-48 17 -Om. 0.48 0.2 0.4 0.18 5-7-48 17.5-Om. 1.85 0.6 1.45 0.75 15-7-48 19 -Om. 1.9 0.65 2.5 0.90 25-7-48 17 -Om. 1.35 0.52 3.4 1.54 7-8-48 16.5-Om. 3.6 1.55 6.0 2.25 3-9-48 16 -Om. 3.4 1.65 6.4 3.2 9-10-48 17 -Om. 1.3 0.7 3.3 1.6 TABLE XXIII 128 Q u a n t i t a t i v e a n a l y s i s o f Borgeson l a k e p l a n k t o n c o l l e c t i o n s T o t a l o f t h r e e h a u l s No. 20 p l a n k t o n n e t T o t a l of t h r e e h a u l s No. 10 p l a n k t o n n e t Depth S e t t l e d C e n t r i - f u g e Dry wt. S e t t l e d C e n t r i - f u g e of h a u l •VEOI. i n v o l . i n i n v o l . i n v o l . i n cc. c c . gm. c c . c c . 27-7-47 18 -Om. 4.8 2.05 .128 6 -Om. 1.6 0.95 12 -6m. 4.2 1.87 18 -12m. 1 .7 0.60 5-8-47 13 -Om. 3.7 1.75 .205 6 -Om. 2.45 1.13 12 -6m. 2.40 0.8 18 -12m. 1.60 0 .5 13-8-47, 17 -Om. 3-9 1.8 .101 11 6 -Om. 3.0 1.42 12 -6m. 1.65 0.6 11 17 -12m.• 1 .5 0 .54 27-8-47 17 -Om. 3-3 1.45 .194 6 -Om. 2.6 0 .93 12 -6m. 1.55 0 .5 17 -12m. 0.68 0.24 11-9-47 18 -Om. 2.0 0.55 .025 19-9-47 18 -Om. 1 .7 0 . 9 .039 11-9-47 18 -Om. 2 .5 1.15 19-9-47 18 -Om. 0.75 0.28 One h a u l One h a u l No. 20 p l a n k t o n net No. 10 p l a n k t o n n e t C e n t r i C e n t r i Depth S e t t l e d - f u g e S e t t l e d - f u g e of h a u l v o l . i n v o l . i n v o l . i n v o l . i n % ^ . c c . c c . c c . c c . 10-5-48 17 -Om. 0 .43 0.21 0 .5 0.16 31-5-48 16 -Om. 0.8 0.2 0.48 0.14 6-7-48 16 .5-0m. 1.55 0.66 1.04 0.45 16-7-48 16 -Om. 1.65 0.60 1.60 0 .98 26-7-48 16 -Om. 2.0 0.78 3.1 1.25 7-8-48 16 -Om. 5.05 2 .7 6 .3 2 .9 4-9-48 16 -Om. 3.4 1. 2 7-7 3-5 9-10-48 17 -Om. 5.15 2.2 23.5 12.1 TABLE XXIV 129 Quantitative analysis of Allison lake plankton collections One haul No. 20 plankton net One haul No. 10 plankton net Centri Centri Depth Settled -fuge Settled 1 -fuge of haul vol . in vol . in vol . in vol . in cc. cc. cc. cc. 10-5-48 30-Om. 0.48 0.26 1.2 0.6 1-6-48 30-Om. 1.8 0.88 2.4 1.3 7-7-48 31-0m. 2.55 1.1 4.2 2.2 17-7-48 33-Om. 3.4 1.5 5-9 3.1 27-7-48 40-Om. 2.0 1.5 3.4 1.85 9-8-48 39-0m. 2.25 1.15 4.7 2.8 6-9-48 39-Om. 1.65 0.71 4.4 2.1 9-10-48 35-Om. 0.9 0.45 2.2 1.12 13P TABLE XXV McCafferty lake plankton collections in thousands No. 20 Syne Fragll Asterio Dyno - Perid- Cerat Polyar Kerat net -dra - lar ia -nella bryon inium -ium -thra -•ella 25-7-47 5688 1943 758 47 14.1 1. 0 12.1 51-7-47 1849 1659 308 389 18.7 8.5 14.1 11*8-47 4550 2417 640 450 36.4 4. 9 3.3 16-8-47 27540 • 4764 1896 474 61.9 4.6 1.3 13^9-47 6636 758 24 118 39.7 0. 7 2.0 23-9-47 11380 1090 0 521 14.1 2.6 2.6 9-5-48 16 8 8 5.8 1.3 1-6-48 71 1185 24 332 12 0,7 28. 5 3.9 5.7-48 9 675 26 66 135 3.3 28.8 9.2 15-7-48 261 71 36 39 0.3 11.5 2.6 25-7-48 12 2050 258 199 196 0.3 12.8 1.3 6-8-48 2370 735 948 498 4.3 2. 9. 2.6 17-8-48 14 4787 332 455 957 4.3 3. 9 1.6 3-9-48 21 3768 55 38 341 43.3 1.0 1.3 9-10-48 640 62 26 24 0. 7 0.3 No. 20 Noth- Asplan Triar Daph Cerio- Bos- Diap- Cyc- Naup-net olca -chna -thra -nia diaphnia mina tomus lops lius 25-7-47 2.9 0.7 9.2 25.2 0.7 1.0 20.3 40.3 31-7-47 5.2 8.2 17-0 2.6 1. 1 17.4 30.1 11-8-47 5.9 0.3 6.6 17.4 0.3 2.0 13.1 20.6 16-8-47 3-3 0.3 4.3 14.4 0.0 1. 0 7.5 15.1 13-9-47 1.6 0.3 2.9 6.9 1.3 0. 2 3-3 13.8 23-9-47 2.9 3.3 8.5 0.3 7.5 10.8 9-5-48 6.7 0.1 0.1 0.2 6.0 5.1 1-6-48 21.0 1.0 0.4 0. 5 8.2 10.8 5-7-48 10.2 2.9 0.3 3.8 4.1 0.6 20.3 60.3 15-7-48 5.9 2.0 0.3 4.4 4.9 0. 3 5.9 21.6 25-7-48 4.3 2.6 3.6 6.4 1.3 0.3 0.8 5.1 15.7 6-8-48 1.3 0.7 2.0 1.8 0.7 0. 7 5.6 12.1 17-8-48 1.0 0.7 1.5 1.0 0. 1 5-1 13.4 3-9-48 0.3 2.2 2.0 0.3 10.2 11.5 9-10-48 0.3 0.3 0.1 0.7 1.3 No. 10 Noth- Asplan Triar Daph Cerio- Bos- Diap- Cyc-net olca -chna -thra -nla d>aphnia mina tomus lops 13-9-47 3.3 10.5 - 32.8 1.3 1.6 16.7 23-9-47 4.9 0.3 3.3 14.4 0. 7 16.1 9-5-48 15.1 0.3 0.1 0.1 0.1 0.5 13.5 1-6-48 27.9 0.3 1.7 0.6 0.1 0.6 11.5 5-7-48 10.8 5.1 0.3 13.3 10.8 1. 1 31.1 15-7-48 4.9 5.7 0.7 10.5 5.9 0.3 1. 6 14.1 25-7-48 1.0 0.2 0.3 7.7 7.9 0. 9 10.3 16-8-48 0.7 1.0 4.8 5-2 0.6 9.2 17-8-48 1.6 4.6 3.4 0.3 8.7 3-9-48 0.3 3.9 5.9 0. 5 17.2 9-10-48 0.7 0.4 0.1 0.2 2.8 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXVI Laird lake plankton collections in thousands No. 20 Syne Fragil Asterio Dyno-• Perid- Cerat Polyar Kera-net -dra - lar ia -nella bryon inium - ium -thra tella 24-7-47 2488 118 924 24 19 .6 13.1 1-8-47 924 24 403 27 .9 10.8 18.4 12-8-47 166 47 26.5 3. 3 5-2 25-8-47 213 95 37 .0 0. 7 4.3 13-9-47 3318 379 71 34.7 1. 6 5.9 22-9-47 2607 142 24 15 • 7 2. 0 3-9 9-5-48 73 1461 71 0.5 0. 9 ' 1.1 1-6-48 150 3640 35 71 9 0.7 2. 6 4.3 6-7-48 7 3152 21 310 73 0.7 3.6 8.5 16-7-48 5 2097 142 107 34 2.0 6. 2 10.5 26-7-48 2" 5143 204 66 97 1.3 3. 9 5.2 8-8-48 14315 62 21 111 1 .3 3. 6 4.9 4-9-48 2 4053 5 19 43 4.6 1. 6 2.3 9-10-48 1 1232 47 28 1 1 .0 2.6 No. 20 Noth- Asplan Triar Daph Cerio- Bos- Diap- Cyc- Naup-net olca -chna -thra -nla d)aphnla mina tomus lops lius 24-7-47 8.2 0.3 10.0 3-3 2.6 2.1 28.8 12.5 1-8-47 6.6 0.7 0.7 9.5 3.9 3.6 2.8 19.3 8.2 12-8-47 3.9 0.3 2.9 1.5 0.3 0.5 18.0 7.5 25-8-47 2.0 0.3 0.7 4.6 1.3 1.6 13-1 7.2 13-9-47 3.3 1.0 2.3 1.5 0.5 8.7 6.9 22-9-47 2.0 1.0 0.3 2.1 2.3 1.5 10.5 8.8 9-5-48 3.5 0.2 1.5 0.1 9.7 6.2 1-6-48 5-9 0.3 1.0 0.6 5-2 3-3 6-7-48 6.2 0.7 1.3 0.7 2.1 0.8 8.7 5-9 16-7-48 2.0 0.3 1.0 1.5 0.1 0.6 0.3 5.9 2.9 26-7-48 2.3 0.3 1.8 0.3 0.2 0.5 6.7 5-9 8-8-48 0.7 0.3 2.0 1.4 0.1 0.3 7.2 5-6 4-9-48 2.0 1.0 0.9 0.2 0.3 0.1 6.6 4.9 9-10-48 1.0 0.3 0.8 0.2 O'.l 4.8 7.2 No. 10 Noth- Asplan Triar Daph Cerio- Bos- Diap- Cyc-net olca -chna -thra -nia Daphnia mina tomus lops 13-9-47 9.2 1.0 0.7 8.2 6.6 3.9 27.9 22-9-47 3-3 2.8 6.6 9.2 • 6.2 29.2 9-5-48 7.1 0.1 0.7 1.6 0.6 22.1 1-6-48 24.3 0.6 4.8 1.0 32.6 6-7-48 13-1 1.0 1.0 2.5 0..3 3-9 1.2 16.9 16-7-48 10.2 0.5 4.8 1.0 2.3 0.9 19.0 26-7-48 1-3 1.0 0.3 3.6 1.1 1.0 0.9 14.1 8-8-48 2.3 1.3 2.5 0.3 0.5 14.1 4-9-48 0.7 2.0 3.1 1.3 0.4 14.7 9-10-48 1.6 1.1 1.8 1.3 0.3 13.8 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXVII Dry lake plankton collections in thousands 132 No. 20 Syne Fragil Asterlo Dyno- Perid- Cerat Polyar Kera-net -dra - lar ia -nella bryon inium -ium -thra tella 26-7-47 19908 521 640 119 9.5 18.7 4-8-47 4503 924 474 109 4.3 6.2 12-8-47 10072 853 237 78 9.2 2.0 26-8-47 9006 545 47 24 . 3.9 0.7 P 0 I S 0 N E D 12-9-47 118 26780 118 24 21 5.2 1.0 19-9-47 166 14100 355 166 47 14 7-9 0.7 10-5-48 134 7.2 6.9 31.5-48 9 12 9.8 27.2 5-7-48 33 787 185 16.7 18.4 15-7-48 69 2086 55 14.1 8.5 25-7-48 85 1446 14 4 9.2 5.9 7-8-48 14 47 71 45 14 1 3.6 3.6 . 3-9-48 13 28 692 1 1.0 2.3 9-10-48 24 69 9 0.3 1.0 No. 20 Noth- Asplan Trlar Dap% Cerio- Bos- Diap- Cyc- Naup-net olca -chna -thra -nia daphnia mina tomus lops lius 26-7-47 6.6 4.9 2.3 14.4 0.8 4.6 0.7 53.<7 9.2 4-8-47 3.9 1.0 0.7 10.7 2.0 1.6 39.2 4.3 12-8-47 3.9 0.7 ' 2,.0 8.8 0.8 2.0 31.5 5.2 26-8-47 0.7 0.3 7.5 1.6 0.3 16.7 2.2 P O I S O N E D 12-9-47 19-9-47 2.0 0.3 0.7 0.7 0.7 1.6 1.0 0.3 1.6 0.2 10-5-48 1.7 31-5-48 1.6 5-7-48 7.2 15-7-48 7.5 25-7-48 9.5 7-8-48 6.9 3-9-48 1.3 9-10-48 0.7 17.2 32.4 32.8 1.2 16.4 0.8 8.2 0.8 0.1 5-6 3.4 0.1 1.0 2.7 1.1 ( 0 . 2 ) * 0.1 0.2 0.1 0.3 2.1 0.4 0.1 1.6 0.3 0.7 0.5 0.5 2.3 0.3 0.1 3.3 0.1 0.3 2.6 # D.longispina * D. pulex 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXVII (cont'd) 133 Dry lake plankton collections in thousands No. 10 Noth- Asplan Triar Daph^ Cerio- Bos- Diap- Cyc-net olca -chna -thra -nia daphnia mina tomus lop P 0 I S 0 N E D 12-9-47 1.0 1.0 0.3 4.6 0.3 4.6 19-9-47 0.7 0.7 0.5 10-5-48 2.4 18.1 0.1 31.5-48 1.3 28.8 0.1 0.1 5-7-48 12.1 12.5 1.5 0.2 0.8 0.1 15-7-48 21.6 35.4 1.5 1.2 0.3 25-7-48 14.7 0.3 8.5 5-3 0.1 0.8 0.4 7-8-48 5.9 2.9 6.0 0.3 0.9 3-9-48 6.9 1.0 3-0 0.6 0.3 9-10-48 3.2 0.4 1.2 ( 0 . 7 ) * # D. long!spina * D. pulex 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXVIII Borgeson lake plankton collections in thousands No. 20 Syne Fragil Asterio Dyno-- Perid- Cerat Polyar Kera-net -dra - lar la -nella bryon inium -ium -thra tella 27-7-47 1540 592 47 17 2.0 2.3 5-8-47 47 948 284 47 20 0.3 13-8-47 71 592 71 24 47 42 • 0.7 2.9 27-8-47 47 2488 427 95 24 24 5-9 2.9 * P 0 I S 0 N E D H _ 9 - 4 7 47 9954 545 498 24 33 2.0 10.8 19-9-47 166 9006 95 285 36 20.3 4 .9 10-5-48 213 284 10.5 0.3 31.5-48 14 154 2 31 2 4 16.4 16.7 6-7-48 50 225 5 • 7 1 2.9 92.1 16-7-48 12 415 7 36 3 0.3 45.2 26-7-48 7 95 50 280 17 2.0 49-5 7-8-48 24 275 33 19 2.0 22.0 4-9-48 55 166 2 1 0 .7 9-10-48 24 73 1280 JI 5.9 No. 20 Noth- Asplan Triar rr Daph Cerio- Bos- Diap- Cyc-Naup-net olca -chna -thra -nla cDaphnia mina tomus lops lius 27-7-47 1.3 6.4 2.3 5 .4 : 11.6 3.9 2.8 27.9 50 .5 5-8-47 4.3 5 .1 9.0 0.3 2.5 26.5 31.8 13-8-48 0.2 1.3 1.3 3 .3 : 11.1 0.3 1.3 38.0 30 .8 27-8-48 0.7 0 .7 6.4 0 .3 2, .1 22.0 14.1 P 0 I S O N : E D 11-9-47 0.7 0.3 0.3 2.0 7 .4 14.7 19-9-47 2.6 0.2 1.0 0.3 0.2 10-5-48 4.3 31-5-48 13.1 6-7-48 0.8 28.5 0 .1 0.6 0.1 0.3 0.7 16-7-48 2.6 0 . 3 . 0 ,1 2.9 0, .2 0.3 2.0 26-7-48 2.8 0 .2 3.4 0.3 0.4 6.6 7-8-48 • 6.6 1.0 0 .5 5 .6 0 .3 0.5 0.7 7.9 (3 .3 ) * 4-9-48 2.5 (2 .4 ) * 2.5 0.5 0 .4 7.9 9-10-48 (4 .3 )* 0.1 0.1 0.2 3 .6 #D. longispina *D. pulex 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXVIII (cont'd) 135 Borgeson lake plankton collections in thousands No. 10 Noth- Asplan Triar Daph# Cerio- Bos- Diap- Cyc-net olca -chna -thra -nia d>aphnia mina tomus lops P 0 I S O N E D 1 1 - 9 - 4 7 0.2 1.0 3.9 2.0 19.0 1 9 - 9 - 4 7 2.9 0 . 7 0 . 7 .2.0 0.3 1 0 - 5 - 4 8 8 . 2 3 1 . 5 - 4 8 20.0 6 - 7 - 4 8 0 . 7 7 . 7 6.9 0.1 1.2 0.3 0.9 0.3 1 6 - 7 - 4 8 11.1 0 . 4 8 . 5 0.6 1 . 4 2 6 - 7 - 4 8 4 . 3 0 . 7 0 . 8 9.2 0.3 0.5 1.0 7 - 8 - 4 8 0 . 7 1 5 . 4 2.0 ( 4 . 3 ) * 21.3 1.3 1.0 3.9 4 - 9 - 4 8 2.6 ( 8 . 9 ) * 4 . 6 0 . 4 2.$> 9 - 1 0 - 4 8 0.5 0.2 0.1 1.5 (10.2)* #D. longispina *D. pulex 1 9 4 7 values represent a total of 3 hauls; 1 9 4 8 , one haul only. TABLE XXIX Allison lake plankton collections in thousands No. 20 Syne Fragil Asterio Dyno- Perid- Cerat Polyar Kera-net -dra - la r ia -nella bryon inium -lum -thra tella 10-5-48 71 474 118 1.3 3.6 1-6-48 47 273 14 201 2 4.6 1.3 7.5 7-7-48 45 3958 66 95 14 23.3 2.9 21.6 17-7-48 2 592 377 137 20 9.8 5.9 18.4 27-7-48 5 3128 557 178 17 21.3 1.0 8.8 9-8-48 5451 315 31 25 46.9 3.3 6.2 6-9-48 3982 180 9 24.6 1.3 0.7 9-10-48 5 1386 213 9 12.5 0.3 0.3 No. 20 Noth- Asplan Triar Daph Cerio- Bos- Diap- Cyc- Naup-net olca A-chna -thra -nia d'aphnia mina tomus lops lius 10-5-48 1.3 0.3 0.1 3.6 1.3 1-6-48 5.6 1.6 0.1 0.3 0.5 9.8 5.2 7-7-48 14.1 2.1 0.7 1.2 1.8 5.1 0.5 13.4 7.2 17-7-48 11.5 1.1 1.6 2.8 2.9 8.2 2.9 16.4 6.6 27-7-48 6.9 2.3 0.7 1.2 0.4 3.6 1.6 7.2 6.2 9-8-48 2.9 1.5 3.3 1.0 0.7 3.3 1.1 4.8 7.5 6-9-48 0.7 2.6 0.8 0.3 . 0.3 0.8 3.8 1.6 9-10-48 0.7 0.3 1.0 0.8 0.3 0.3 1.0 4.6 No. 10 Noth- Asplan Triar Daph Cerlo- Bos- Diap- Cyc-net olca -chna -thra -nia ci) aphnl a mina tomus lops 10-5-48 4.9 0.3 0.3 0.1 23.6 1-6-48 11.8 1.6 0.2 0.1 0.6 0.7 17.7 7-7-48 21.0 8.4 0.7 2.1 1.8 10.0 3.7 25.6 17-7-48 45.9 5.5 6.4 2.5 13.3 5-3 20.2 27-7-48 4.3 3.8 0.7 2.6 2.0 9.5 3.1 12.1 9-8-48 7.9 4.8 3.6 2.3 0.8 13.6 2.0 12.9 6-9-48 2.0 2.9 4.9 3.3 1.3 3.3 6.7 9-10-48 0.3 0.7 0.7 1.5 1.7 1.7 3.3 1947 values represent a total of 3 hauls; 1948, one haul only. TABLE XXX 137 Percentage volumes of No. 20 plankton collections McCafferty lake Laird lake Phyto- Pro- Roti Entomc >- Phyto- Pro- Roti Entomo-plankton tozoa f era straca plankyon tozoa f era straca 1947 1947 25-7 4 5-5 1 89.5 24-7 0.5 7.5 1 91 31-7 4 3 0.5 92.5 1-8 0 4 2 94 11-8 6 6 1 87 12-8 1 1 0.5 97.5 16-8 16 20 1 63 25-8 0.5 0 1.5 98 13-9 8 1 1.5 89.5 13-9 4 2 5 89 23-9 9 0.5 0.5 90 22-9 2 0.5 4 93.5 1948 1948 9-5 0 0.5 4 95-5 9-5 2 0 1 97 1-6 1 12 8 79 1-6 8.5 4 3.5 84 5-7 0 1 8 91 5-7 1.5 9 2 87.5 15-7 0.5 1 8.5 90 16-7 3 4.5 4.5 88 25-7 8 4 9 79 26-7 5 2.5 3 89.5 6-8 6 26 4 64 8-8 8 1 1 90 3-9 2.5 2 0 95.5 4-9 '3.5 1 1.5 94 9-10 9 7.5 , 4 79.5 9-10 3.5 2 2 92.5 Dry lake Borgeson lake 1947 1947 26-7 2 3-5 4.5 90 27-7 1.5 0.5 7.5 90.5 4-8 2 3-5 1.5 93 5-8 1 0.5 5-5 93 12-8 3 2.5 1.5 93 13-8 0 0.5 2 97.5 26-8 4 1 0.5 94.5 27-8 2 1.5 0.5 96 Poisoned Poisoned 12-9 45 1.5 7 46.5 11-9 10 17 1 72 19-9 41 16 4 39 19-9 16.5 29 9.5 45 1948 1948 10-5 3.5 0 79 17.5 10-5 1.5 87.5 11 0 31-5 1 6 84.5 8.5 31.5 1.5 11.5 87 0 6>7 17.5 13.5 30 39 6-7 0.5 72.5 17.5 9.5 15-7 58.5 11 10 20.5 16-7 21 14.5 13 51.5 25-7 57.5 1 12 29-5 26-7 0.5 32.5 21.5 45-5 7-8 1.5 2.5 5.5 90.5 7-8 0.5 2 2 95-5 3-9 1.5 32 10.5 56 4-9 0 1.5 6.5 92 9-10 4.5 1.5 1 93 9-10 0 5 1.5 93.5 Allison lake 1948 10-5 39.5 8 1.5 51 1-6 0.5 9 2 88.5 7-7 2 2 9 87 17-7 1.5 2 3-5 93 27-7 5 4.5 10.5 80 Volumes expressed to nearest 9-8 5-5 1.5 10 83 0.5 per cent 6-9 6.5 0.5 2.5 90.5 9-10 8.5 1.5 6.5 83.5 TABLE XXXI 138 Quantitative Analysis of Bottom Dredgings of McCafferty lake. l-8m. (with weed) 1947, eight dredgings 1948, five dredgings Number Wt. in gms. Number Wt. in 1 Planaria 214 .8129 19 .0861 Ollgochaeta 4 .0050 4 .0028 Hirudinia 11 .1381 7 .0904 Gammarus 9 . 0870 13 . 2105 Hyalella 94 .0846 240 .2886 Ephemeroptera 27 .0677 Odonata 24 . 4080 5 .1826 Trichoptera 6 .3600 6 • 3672 Dlptera 194 . 2594 87 .1141 Hydracarina 6 1.4100 TOTAL 2.155° 414 Weed 743.8 125.7 Per gm. of weed .75 .003 3.29 .001 Per sq.m. 1390 5-3875 1656 5.6400 1.5-3.Om. (without , weed) 1947, two deedglngs Number Wt. in gms. Gammarus 4 .0212 Hyalella 5 .0074 Odonata 1 .0088 Coleoptera 1 .0009 Diptera 3 .0074 TOTAL 14 .0457 Per sq.m.' lh~6 .457 8-11.2m. (mud) Ollgochaeta Ephemeroptera Neuroptera Chironomus Chaoborus TOTAL Per sq.m. 1947, five dredgings Number Wt. in gms. 1948, ten dredgings Number Wt. in gms. 3 •1 12 .0879 .0879 .352 11 2 1 225 15 254 508 .0121 .0090 .0420 3.1331 .0466 3.2428 6.4856 TABLE XXXII • 139 Quantitative Analysis of Bottom Dredglngs of Laird lake. l-6m. (with weed) 1947, six dredgings 1948, five dredgings Number Wt. in gms. Number • Wt. In gms. Planar!a 3 .0212 6 .0174 Nematoda 1 .0009 Oligochaeta .0.994 5 .0037 Hirundinia 8 3 .0197 Gammarus 5 .1713 15 .0857 Hyalella 12 .0611 213 .3242 Ephemeroptera 1 .0015 6 .0581 Odonata 5 .0382 10 .0581 Trichoptera 9 .4198 17 .6834 Diptera 123 . 2656 71 .1499 Hydracarina 1 .0018 1 1.4002 TOTAL 168 1.0808 347 Weed 214.7 81.3 Per gm. of weed .78 .005 4.27 .017 Per sq.m. 559 3.60 1388 5.60 2-8m. (without weed) 1947, five dredgings Number Wt. In gms. Oligochaeta Gammarus Trichoptera Diptera Per sq.m. TOTAL 1 1 13 1 5 60 .0283 .0241 .0983 •1507 .60 1948, one dredging Number Wt. in gms. 2 .0046 56 .6691 5 8 .6757 1160 13.4740 12.5-20.5m. (mud) Oligochaeta Chlronomus Chaoboru,s Hydracarina TOTAL 1947, four dredgings Number Wt. in gms. Per sq.m. 1 148 149 745 .0014 1.9553 1.9567 9.78 1948, nine dredgings Number Wt. in gms. 4 335 6 44 389 864 .0058 3-4635 .0062 £.4755 7.72 TABLE XXXIII 140 Quantitative Analysis of Bottom Dredgings of Dry lake. l-7m. (with weed) 1947, five dredgings Number Wt. in gms. 1948, five dredgings Number Wt. in gms. Ollgochaeta 28 .0920 44 .3348 Hirudinea 7 .1416 Hyalella 33 .0736 Ephemeroptera 1 .0044 2 .0130 Trichoptera 4 .1614 Coleoptera 7 .0238 Hemiptera 2 .0052 Diptera 117 .0923 70 .1968 Hydracarina 4 .5446 TOTAL 203 .5943 116 Weed 111.1 13.7 Per gm. of weed 1.83 .0053 8.47 .040 Per sq.m. 812 2.3772 454 2.1784 l-9m. (without weed) 1947, five dredgings Number Wt. in gms. Ollgochaeta 1 .0027 Hyalella 2 .0075 Ephemeroptera 1 . 0 0 5 9 Trichoptera 1 .0170 Hydracarina 1 .0023 TOTAL 6 .0356 Per sq.m. 24 .1424 12-18.5m. (mud) Ollgochaeta Hirudinea Hyalella Ephemero pt era Chironomus Chaoborus 1947, five dredgings Number Wt. In gms. 55 1 40 10 TOTAL 106 .2091 .0024 .4391 .0384 .6890 1948, ten dredgings Number Wt. in gms. 97 1 1 73 182 354 • 7723 .0010 .0010 .5183 .8960 2.1886 Per sq.m. 424 2.7560 Ti0.8 4-3*72 TABLE XXXIV 141 Quantitative Analysis of Bottom Dredgings of Borgeson-'Lake ijr-4m. (with weed) 1947, four dredgings 1948, five dredgings Number Wt. in gms. Number Wt. in gms. PlanarIa 31 .1897 Ollgochaeta 2 .0064 Hirudinea 5 .0550 Gammarus 369 3.0079 24 • 3735 Hyalella 247 .3499 36 .0600 Ephemeroptera 1 . 0008 11 .1337 Odonata 78 .9412 21 • 5691 Trichoptera 9 .7436 Coleoptera 1 .0040 Dlptera 63 .2237 116 .2742 Hydracarina 2 . 0046 TOTAL 807 5.5228 209 1.4145 Weed 472.7 69.1 Per gm. of weed 1.71 <012. 3.02 .020 Per sq.m. 4035 27.6140 836 5 . 6 5 8 O l-5m. (without weed) 1947, six dredgings Number Wt. in gms. Hyalella 5 .0089 Trichoptera 2 . O 8 5 8 TOTAL 7 .0947 Per sq.m. 23 .3154 12.5-I8m. (mud) 1947, five dredgings 1948, ten dredgings Number Wt. in gms. Number Wt. in gms. Ollgochaeta 3 .0142 Odonata 1 .9520 Chironomus 2 .0074 5 .0156 Chaoborus 3 .0107 3 .0013 TOTAL 5 .0181 12 .9831 Per sq.m. 20 .0724 24 1.9662 TABLE XXXV 142 Quantitative Analysis of Bottom Dredgings of Allison lake. l£-2m. (with weed) 1948, four dredgings Number Wt. In gms. Hyalella Ephemeroptera Trichoptera Coleoptera Chironomus Hydracarina TOTAL 4 .0043 1 .0005 1 .0140 2 .0110 20 .0112 2 30 .0410 Weed 19.3 Per gm. of weed 1.55 .002 Per sq.m. 150 .2050 10-23m. (mud) 1948, seven dredgings Number Wt. in gms. Ollgochaeta 11 .0058 Chironomus 147 1.2554 Hydracarina 4 TOTAL 162 1.2612 Per sq.m. 462 3.603 , 30-37m. (mud) 1948, four dredgings Number Wt. in gms. No organisms 0"; 0" 143 L I T E R A T U R E C I T E D Birge, E .A. , and C. Juday 1914 - A limnplogical study of the Finger lakes of New York. Bull . U.S. Bur. Fish.(for 1912) 32: 525-609. Brown, C.J .D. , and R.C. Ball Brown, L.A„ 1942 - A fish population study of Third Sister lake. Trans.Am.Fish.Soc., 72: 177-86 1929 - The natural history of cladocerans in relation to temperature. Am. Nat., 63: 248-68 Carl, G.C. 1936 - Food of the coarse-scaled sucker. (Catostomus macrocheilus Girard) J. Biol . Bd. Can. 3*. 20-5 1940 - The distribution of some cladoceran and free-living copepoda in B .C . . Ecol. Monog., 10: 55-110 Carl, G-.C. , and W.A. Clemens 1948 - The fresh-water fishes of British Columbia. B.C. Prov. Museum. Handbook No.5 Victoria, 132 pp. Clemens, W.A. 1934 - The predator and coarse fish problem in relation to fish culture. Trans. Am. Fish. S o c , 64: 318-22 Clemens, W.A., D.S. Rawson, and J .L. McHugh 1939 - A biological survey of Okanagan lake, British Columbia. Bull . Fish. Res. Bd. Can., 56. 144 Hart, J .S. 1947 - Lethal temperature relations of certain fish of the Toronto region. Trans. Royal Soc. Can., 41: 57-71 Heilbrunn, L.V. 1937 - An outline of general physiology. Philadelphia, x l l 4-748 pp; Jewel, Minna E. Juday, C. 1927 - Ground water as a possible factor in lowering dissolved oxygen in the deeper water of lakes. Ecol . , 8: 142-143 1916 - Llmnologlcal apparatus., Trans. Wisconsin Acad. S c i . , 18: 566-592. Juday, C , and E.A. Birge Lacky, J.B Leonard, J.l MacPhee, Craig 1932 - Dissolved oxygen and oxygen consumed in the lake waters of northeastern Wisconsin. Trans. Wis. Acad. S c i . , Arts, Let. , 27: 415-86 1938 - A study of some ecologlc factors affect-ing the distribution of protozoa. Ecol. Monog., 8: 501-27 1938 - Notes on the use of derris as a fish poison. Trans. Am. Fish. S o c , 68: 269-80. 1948 - A preliminary report on the removal of coarse fish by poisoning. Proc. 2nd Annual Game Convention. Prov. of B.C. Game Dep't. , 52-56 McEwen, G.F. 1929 Meehean, O.L. 1941 M'Gonigle, R.H. 1938 Rawson, D.S. 1934 1936 1939 Rice, H.M.A. 1947 Ricker, W.E. 1932 1937 145 A mathematical theory of the vertical distribution of temperature and salinity in water under the action of radiation, conduction, evaporation, and mixing due to the resulting convection. Bul l . Scripps Inst. Oceanography\; 2: 199-306 Fish populations of five Florida lakes. Trans. Am. Fish. S o c , 71: 184-94 Temperature characteristics for certain fresh waters. Proc. Nova Scotian Inst. Sci . ,19: 428-38 Productivity studies in lakes of the Kamloops region, B.C. B u l l . B io l . Bd. Can., 42: 1 - 3 1 . Physical and chemical studies in lakes of the Prince Albert Park, Saskatchewan. J. Biol . Bd. Can. 2 : 227-84. Some physical and chemical factors in the metabolism of lakes. Problems of Lake Biology. Am. Ass. Adv. S c i . , Pub. 10, 9 - 2 6 . Geology and i.mineral deposits of the Princeton map-area, British Columbia. Geol. Surv., Mem. 243. The ut i l i ty of nets in fresh-water plank-ton investigations. Trans. Am. Fish. S o c , 6 2 : 292-303 Physical and chemical characteristics of Cultus lake, British Columbia. J. B i o l . Bd. Can. 3: 363-402. 146 Riley, G.A. 1939 - Limnological studies in Connecticut. Ecol. Monog., 9: 53-94 Smith, M.W. 1939 - Copper sulphate and rotenone as fish poisons• Trans. Am. Fish. S o c , 69: 141-57; 1940 - Treatment of Potter's lake, New Brunswick, witho rotenone,. Trans. Am. Fish. Soc., 70: 347-55 Thienemann, A. 1927 - Der Bau des Seebeckens in seiner Bedentung fur den Ablauf des Lebens im See . Verh. Zool. Bot. Ges., 77: 87-91. Vestal, E.H. 1942 - Reclamation with rotenone of Crystal lake, Los Angeles county, California. California fish and game, 28: 136-42. Welch, P.S. 1935 - Limnology. New York and London. 471 pp. 1948 - Limnological Methods. Toronto, x v i i l 4- 381 pp. Wiebe, H.A.:,. A.M.. .McGavock, A.C. Fuller, and H.C. Markus. 1934 - The ability of fresh-water fish to extract oxygen at different hydrogen-ion concentrations. Physiol. Zool., 7: 435-48. 

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