bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence of Trematode Parasites of American Plaice (Hippoglossoides platessoides) of the Scotian Shelf and Gulf of St. Lawrence in Relation to Fish Length and Food
Authors: Scott J. S.
Published: April 2011

The following digenetic trematodes were found in the alimentary tract of American plaice (Hippoglossoides platessoides) from the Scotian Shelf and Gulf of St. Lawrence: Derogenes varicus, Fellodistomum furcigerum, Lecithaster gibbosus, Stenakron vetustum, Steringotrema ovacutum, Zoogonoides viviparus, Hemiurus levinseni, Otodistomum veliporum (larvae), Podocotyle atomon, Prosorhyncus squamatus.The incidence of several trematode species changed with length of fish and associated changes in the fish’s diet. Incidence of D. varicus and S. vetustum decreased with increase of host length, whereas incidence of R. ovacutum and Z. viviparus increased. Lecithaster gibbosus and S. furciger showed little change in incidence. Correlations between parasite incidence and frequency of occurrence of food items indicated that small crustaceans may be intermediate hosts for S. vetustum and D. varicus; sea urchins may be intermediate hosts for R. ovacutum and brittle stars for Z. viviparus.
Genetic Studies of Fish.
Authors: Utter Fred M.
Published: April 2011

not available
System Simulation of the Predatory Activities of Sea Lampreys (Petromyzon marinus) on Lake Trout (Salvelinus namaycush)
Authors: Lett Patrick F. , Beamish F. W. H. , Farmer G. J.
Published: April 2011

A stochastic dynamic model was developed to evaluate the simulated and empirical interactions between sea lampreys (Petromyzon marinus) and two lake trout (Salvelinus namaycush) population structures, one without and the other with previous lamprey predation.An arithmetic increase in lampreys induced a geometric decline in trout, which was dependent on the number of age-classes and the mean weight of trout. Large trout, when present, were subject to most of the lamprey predation allowing survival of smaller trout. Lethality increased exponentially with lamprey size resulting in peak lake trout mortality during fall near the end of the lamprey’s feeding period. Lake trout scarring data could be used only as an index of lamprey abundance when trout:lamprey ratios and trout population structures were known. The simulation suggested that sea lampreys and lake trout could coexist if large trout are not removed by commercial fishing and if some exogenous factor controlled lamprey abundance.
Spawning Behavior of Chum Salmon (Oncorhynchus keta) and Rainbow Trout (Salmo gairdneri)
Authors: Tautz A. F. , Groot C.
Published: April 2011

Detailed accounts of the spawning behavior of chum salmon (Oncorhynchus keta) and rainbow trout (Salmo gairdneri) in laboratory flumes are provided. The behavioral activities, quivering, probing, and crossing over increase in frequency as a function of time prior to spawning whereas digging remains constant or decreases slightly. Maps of digging locations and movie films suggest nest shape and current pattern are monitored by the female, allowing her to intensify her digging activity near the center of the nest. Probing appears to be a signal to the male indicating approach of oviposition and also provides information to the female regarding the shape and suitability of the nest site. The probing act is also used in the synchronization of the male and female spawning acts. Changes in velocity do not appear to markedly affect nest construction either in terms of number of digs to oviposition or in size of nest constructed. It is inferred that velocity and gravel size are important insofar as they influence the construction of a suitable nest depression. Nest sites would appear to be selected on the basis of acceleration of flow rather than velocity per se though high limits must obviously exist.
Reproductive Guilds of Fishes: A Proposal and Definition
Authors: Balon Eugene K.
Published: April 2011

The emergence of efficient ecosystem modelling is severely hampered by the need for an ecological classification of fishes. An earlier concept of ecological groups is here expanded to cover all living fishes. This ecological classification is based mainly on form and function in early developmental intervals, on preferred spawning grounds, and on features of reproductive behavior. Within the adaptations for reproduction and embryonic development two factors prevail — predators and the oxygen regime; consequently, spawning behavior and spawning grounds determine ensuing respiratory conditions and available protection from predators. The remaining factors are more or less associated with those two. From the point of view of resource exploitation, factors other than feeding habits governing density, biomass, and production are more important. In this sense reproductive guilds are more meaningful than feeding strategies, to which one usage of "guild" was limited.Thirty-two guilds putatively encompass all the 30,000 living fish taxa (or about 20,000 species) and form an ecological classification unrelated to the Linnean classification. The guilds retain phyletic significance in respect to reproductive systems and form a basis for the construction of models on natural and cultural succession. Number of guilds and frequency of taxa within guilds in a given area reflect geochronological sequences and invasion abilities of members of different guilds.
Netting Materials for Fishing Gear.
Authors: Carrothers P. J. G.
Published: April 2011

not available
Limited Arsenic Dispersion in Sea Water, Sediments, and Biota Near a Continuous Source
Authors: Penrose William R. , Black Robert , Hayward Michael J.
Published: April 2011

Moreton’s Harbour, Newfoundland, has been exposed to arsenic-bearing drainage and leaching from a stibnite mine for at least 38 yr and possibly longer than 84 yr. Measurements of inorganic arsenic in sea water and sediments and total arsenic in some marine organisms revealed a very limited influence of continuous exposure to arsenic in the small harbor. Arsenic concentrations in surface water declined to normal within 200 m, and in sediments within 50 m. Animals did not show significantly higher levels nearer the mine, with the exception of the sea urchin Strongylocentrotus droebachiensis, which accumulated significantly higher levels of arsenic adjacent to the mine site.
Hepatic Morphology and Acid Phosphatase Localization in the Channel Catfish (Ictalurus punctatus)
Authors: Kendall M. W. , Hawkins W. E.
Published: April 2011

Livers of 50 channel catfish (25–15 cm long) obtained by seining from the Ross Barnett Reservoir near Jackson, Mississippi were subjected to light, electron microscopic, and enzyme histochemical examination to describe the hepatic parenchyma and exocrine pancreas as well as localize acid phosphatase. Similar to that of other fish species, catfish liver parenchyma consisted of laminae of dual-plated muralium and, unlike that of many species, dispersed exocrine pancreatic tissue was observed circumscribing the portal vein, its tributaries, hepatic artery, and its branches. Acid phosphatase activity was histochemically localized to reaction product in lysosomal-like bodies arranged in peribiliary canalicular patterns. Electron microscopic observations were consistent with the above observations and biliary canaliculi were noted with long microvillar processes occupying their lumens. The exocrine pancreatic cells contained granular endoplasmic reticulum, free ribosomes, Golgi bodies, and numerous membrane-bound zymogen granules.
A Periscopic Method for Determining the Three-Dimensional Positions of Fish in Schools
Authors: Pitcher T. J.
Published: April 2011

The Cartesian coordinates of fish schooling in aquarium tanks are estimated by combining a periscope image via mirrors with a direct view on one photograph. Systematic errors from simple geometrical estimates based on parallax are accurately compensated by calibration using multiple polynomial regression. Once calibration has been carried out, the periscope method has advantages over others in using standard photographic equipment, in reducing measuring time, and in the identification of fish.
Modelling the Eutrophication Process.
Authors: Schindler D. W.
Published: April 2011

not available
Chemoreception in Marine Organisms.
Authors: McLeese D. W. , Sutterlin A. M.
Published: April 2011

not available
Comparative Uptake of a Polychlorinated Biphenyl and Dieldrin by the White Sucker (Catostomus commersoni)
Authors: Frederick Lynn L.
Published: April 2011

White suckers (Catostomus commersoni) accumulated the PCB Aroclor® 1232 and dieldrin from water at approximately the same rate. However, they accumulated higher PCB levels than dieldrin levels when exposed to equivalent concentrations of these substances. The uptake pattern of Aroclor 1232 components on a whole fish basis and in gill and intestinal tissue was similar to Aroclor 1232 components to which the fish were exposed. The presence of additional components having short chromatographic retention times was observed in liver, brain, and kidney tissues in fish exposed only to Aroclor 1232.
Deep water Exchanges in Bute Inlet, British Columbia
Authors: Lafond C. A. , Pickard G. L.
Published: April 2011

Bute Inlet is a fjord of the British Columbia mainland coast connected to the Strait of Georgia through Sutil Channel. The properties of the waters in the inlet were observed during a series of cruises from June 1972 to June 1974 with the main objective of determining the water exchange below the top 100 m.Vertical longitudinal sections and time-series plots of salinity, temperature, and dissolved oxygen distributions measured during the 2-yr survey were used to analyze the circulation patterns and renewal processes of the water below 100 m.Inflows of deep water from the Strait of Georgia into Bute occurred frequently during the study period, and took place when the water from the Strait of Georgia above the inlet sill depth was denser than the water in the basin of the inlet. Volumes of some inflows into Bute were estimated, and calculations indicate that inflow speeds could be large enough to be recorded by existing current meters. The renewal of the deep water in Bute Inlet basin appears to be basically consistent with the annual cycle of deepwater replacement in the Strait of Georgia with its year-to-year variations.
Fisheries and Energy Production. A Symposium
Authors: Efford Ian E.
Published: April 2011

not available
Heavy Metal and Chlorinated Hydrocarbon Residues in California Sea Lions (Zalophus californianus californianus)
Authors: Buhler Donald R. , Claeys Robert R. , Mate Bruce R.
Published: April 2011

Samples of various tissues and organs from healthy California sea lions (Zalophus californianus californianus) and sick animals (apparently with leptospirosis) collected along the central Oregon coast in 1970, 1971, and 1973 were analyzed for total mercury, methylmercury, cadmium, and chlorinated hydrocarbons. Maximum mercury concentrations of 74–170 ppm occurred in sea lion liver, but only 1.6–3.7% of this was present as methylmercury. Cadmium was concentrated primarily in the kidney which contained 7.2–12.0 ppm of the metal. Chlorinated hydrocarbon residues in sea lion fat ranged between 253–475 ppm DDE, and 21.2 and 34.1 ppm PCB. Although mercury, cadmium, and chlorinated hydrocarbon residues in some of the sick sea lions were significantly higher than those present in healthy animals, it is not possible to relate these differences to the onset of leptospirosis.
Some Concepts and Descriptions of Physiological Tolerance: Rate–Temperature Curves of Poikilotherms as Transects of Response Surfaces
Authors: Alderdice D. F.
Published: April 2011

Precht rate curves may be considered as transects across a rate surface bounded by a Fry temperature polygon. Changes in metabolic or active capacity within the tolerance polygon approximate capacity changes within Precht’s normal range of temperatures. Precht’s resistance adaptations are consequences of change in capacity occurring in the zone of resistance of Fry.The turning-point axis of Precht rate curves is assumed analogous to the axis of maximum rate at acute temperatures (test-temperature axis), using an activity surface as a model. Parallelism is suggested between this axis and the upper incipient lethal temperature boundary where the latter may be unknown.In the standard comparison of cold-adapted and warm-adapted rates, Precht compensation types can depend on the nature of the capacity surface and on the choice of acclimation temperatures. Reasonable and paradoxical resistance adaptations reflect characteristics of the capacity surface, in particular the turning-point axis, in relation to the acclimation and acute temperature axes of measurement. Resistance adaptations appear directly related to the course of the incipient lethal boundaries on a rate surface. Further understanding of capacity surfaces probably requires that a minimum of five transects be made across a surface, rather than the two generally made for warm-adapted and cold-adapted comparisons.In such studies, meaningful measures of acute response require extended understanding of the nature and time course of thermal acclimation, and of the potential biases embedded in a response arising from other temperature-dependent compartments of metabolic demand. The need is demonstrated for a quantitative distinction between thermal resistance and tolerance in cells and microorganisms, equivalent to the incipient lethal temperature boundaries of Fry. Such determinations, above all, require that temperature level and exposure time not be confounded.
A New Approach to Fisheries Management and F. E. J. Fry’s Role in Its Development
Authors: Loftus K. H.
Published: April 2011

Fisheries management has undergone a complex and tortuous process of development. From its initial stages as a largely intuitive activity, gradual incorporation of a biological basis has greatly strengthened its effectiveness. At present, there is considerable promise that a coherent, scientifically sound body of management science will soon emerge. The influence of F. E. J. Fry is inextricably associated with these developments.
Oxygen Depletion in the Central and Eastern Basins of Lake Erie, 1970
Authors: Burns N. M.
Published: April 2011

The hypolimnetic oxygen depletion rate is required to be measured to an accuracy of approximately 3% if major changes in the trophic state of Lake Erie are to be documented within about 5 yr of the change commencing. Depletion rate measurements of this level of accuracy require a knowledge of the reoxygenation of the Central and Eastern basin hypolimnia and the transport of oxygen between the hypolimnia. A model is described here that enables an estimate of the degree of hypolimnetic reoxygenation to be made. The transport of oxygen between the hypolimnia was estimated by means of a hydrodynamic model. The resultant calculations gave areal hypolimnetic depletion rate values of 0.43 and 0.87 g O2 m−2 day−1 for the Central and Eastern basins, respectively, and volumetric depletion rates of 0.13 and 0.057 g O2 m−3 day−1, respectively, for these basins during 1970.
Numerical Computations of Advective and Diffusive Transports of Chloride in Lake Erie, 1970
Authors: Lam D. C. L. , Simons T. J.
Published: April 2011

This paper is concerned with a numerical simulation of lakewide advective and diffusive transports of conservative pollutants or nutrients, such as chloride, in Lake Erie. The study is a continuation of a hydrodynamic modeling experiment to compute water circulations throughout the 1970 shipping season, also in this issue, and makes use of ship observations of chloride distributions at approximately 4-wk intervals during 1970, together with estimates of river loadings for the same periods.The model equations are based on the time-dependent, mass-conserving advection–diffusion equation. A vertically mixed, one-layer, two-dimensional model is employed for spring and fall, whereas a two-layer model is used to simulate the stratified lake in summer. The equations are solved by finite-difference formulations on a horizontal grid with a mesh size of 6.67 km. Using time steps of 6 h, predictions are made of the change of chloride concentrations between pairs of cruises and the results are compared with observations.While the advective currents are derived from the previous hydrodynamic study, diffusion coefficients are estimated by comparing model results for a range of coefficients. The resulting numerical values compare favorably with findings of diffusion experiments in actual lake environments.
Experimental Confirmation of the Olfactory Hypothesis with Homing, Artificially Imprinted Coho Salmon (Oncorhynchus kisutch)
Authors: Cooper Jon C. , Scholz Allan T. , Horrall Ross M. , Hasler Arthur D. , Madison Dale M.
Published: April 2011

To test the olfactory hypothesis of salmon homing, fingerling coho salmon (Oncorhynchus kisutch) were exposed to low concentrations of an odorous synthetic chemical, morpholine during presmolt and smolting periods. Equal numbers of these fish were not exposed (controls). Both groups were stocked directly into Lake Michigan near Oak Creek, South Milwaukee Wisconsin. Another paired group of exposed and unexposed fish was released 13 km north of Oak Creek. During the adult spawning migration 18 mo later, morpholine was dripped into Oak Creek and the returning salmon were censused.For four experiments over 2 consecutive yr, the number of exposed and unexposed fish captured at the artificially scented stream were, 216 vs. 28, 437 vs. 49, 647 vs. 65, and 439 vs. 55. These differences were highly significant (P <.001).During the 3rd yr, morpholine was not added to the stream during the spawning migration and exposed and nonexposed fish returned in equal, low numbers (51 vs. 55, P >.05). These results confirm the existence of odor imprinting and long-term olfactory memory in coho salmon, It is possible that this mechanism is also used in the natural imprinting situation.
Food and Food Selectivity of the Black Bullhead, Ictalurus melas, in Lake Poinsett, South Dakota
Authors: Repsys Andrew J. , Applegate Richard L. , Hales Donald C.
Published: April 2011

Food habits and food selectivity of the black bullhead (Ictalurus melas) in Lake Poinsett, South Dakota, were studied from March to November 1970. The black bullhead preyed upon a wide range of food sources in the limnetic, littoral, and benthic zones and seasonal differences in diet occurred in response to availability of prey species. The total food volume in stomachs of 558 black bullheads (143–304 mm total length) comprised about 32% planktonic crustaceans, 25% chironomids, 27% fish, 9% crayfish, 2% filamentous algae, and 5% miscellaneous organisms. Planktonic crustaceans made up 94.4% and chironomids made up 5.6% of the volume of food ingested by 220 young-of-the-year black bullheads. Black bullheads were most selective for the largest cladocerans available, Leptodora kindtii, Daphnia pulex, and D. galeata mendotae, and for Chironomus spp. pupae. Black bullheads were least selective for Diaphanosoma leuchtenbergianum, copepods, and chironomid larvae. The black bullhead in Lake Poinsett was primarily a selective planktivore throughout its life history.
Review of Genetic and Related Studies on Commercial Oysters and Other Pelecypod Mollusks
Authors: Longwell A. Crosby
Published: April 2011

Those aspects of the genetics and the evolution of the oyster and other pelecypod mollusks already elucidated or presently under study are reviewed. The outcome to date of some practical breeding programs in the U.S. is summarized. Comments are made on ways various specialties within the science of genetics can inevitably contribute to commercial production. This is in regard to production on old natural wild beds and newly seeded beds, as well as in regard to intensive production under artificial hatchery conditions. The latter should eventually lead to true domestication of the still wild-type oyster. These are brief remarks on how all this compares to the role of genetics and breeding science in fish culture and to much acclaimed past and current roles of genetics in present-day production of cereal crops and farm animals.
Effects of Mercury and Copper on the Olfactory Response in Rainbow Trout, Salmo gairdneri
Authors: Hara Toshiaki J. , Law Y. M. C. , Macdonald S.
Published: April 2011

The effects of mercury and copper on the olfactory response of rainbow trout (Salmo gairdneri) were studied by perfusing HgCl2 and CuSO4 solutions through the olfactory organs while recording the olfactory bulbar electrical responses to the standard stimulant, L-serine.The olfactory response was depressed during exposure to mercury and copper. The lowest concentrations of mercury and copper needed to cause appreciable effects within 2 h were estimated at 0.10 and 0.008 mg/liter, respectively. The depression increased with increase in the concentration and exposure time of the heavy metals. Recovery of the olfactory response was slower with higher concentrations and longer exposure.The method is rapid, accurate, and sensitive, and can be applied to other toxic chemicals and fish species.
Basket Traps for Surveys of a Gammarid Amphipod, Anisogammarus confervicolus (Stimpson), at Two British Columbia Estuaries
Authors: Levings C. D.
Published: April 2011

Basket traps filled with Fucus distichus, a fucoid alga, were used for assessing the distribution of a gammarid amphipod, Anisogammarus confervicolus, at the Squamish and Cowichan river estuaries in southwestern British Columbia. Over a 17-day period amphipods accumulated in baskets at an exponential rate. Compared with quadrat sampling, basket samplers yielded biomass data more quickly. Distribution patterns determined by quadrat and basket sampling at low tide were similar, but data obtained by the basket samplers may be more useful as they integrate abundance over numerous high tide periods.
Analysis of Large-Scale Ecological Systems
Authors: Kerr S. R. , Neal M. W.
Published: April 2011

Large spatial and temporal scales imply a proportional need for large volumes of data. Ecological systems exhibit different patterns of variability as a function of scale. It follows that large-scale ecological systems are appropriately observed at a number of different spatial and temporal scales, further complicating the data requirements for various kinds of analysis. The concept of an "information model," in conjunction with an effective data base management system, enables an analytical approach to large-scale ecological systems that is relatively unconstrained by preconceived organizational structures in the data base.
An Historical Sketch of Physical Oceanography in Canada
Authors: Campbell Neil J.
Published: April 2011

The history of Canadian oceanography is outlined through the contributions of individual scientists and the organization or programs they were associated with from 1890 to the early 1970s. The period up to 1960 reflects not only the scientific and personal efforts of H. B. Hachey, J. P. Tully, W. M. Cameron, and G. L. Pickard, but also their work in establishing oceanography as a science in Canada. The organizational developments which took place in the 1960s and their culmination in the building of the Bedford Institute of Oceanography, the Canada Centre for Inland Waters, and the Institute of Ocean Sciences now under construction on the west coast are described.
Evidence of a Westward-Flowing "Subarctic Countercurrent" in the North Pacific Ocean
Authors: Tabata S.
Published: April 2011

An examination of surface current velocity data obtained from two independent ship sources suggests the presence of a narrow, weak, westward-flowing countercurrent at a latitude of approximately 50°N in the subarctic Pacific region. Oceanographic survey data collected in the region from the summers of 1958 and 1959 also indicate such a countercurrent extending zonally for more than 1000 km. The countercurrent can be explained by consideration of the wind-stress vorticity field over the region.
Wind and the Surface Circulation of a Fjord
Authors: Buckley J. R. , Pond S.
Published: April 2011

An experiment has been carried out recently to investigate the relative effects of wind, tide, and river runoff on the circulation of the surface layer of a small fjord. Drogues were tracked with a radar set for several days at four locations. Data were recorded photographically and digitized for computer processing to produce the velocity and acceleration of each drogue along its track. Wind forcing was dominant. The river input was important too, causing large horizontal shears in the flow. Tidal effects appeared to be negligible. Frictional coupling between the surface layer and the water below appeared to be very small. A mechanism for the surface layer behavior is proposed with the layer nearly decoupled from the underlying water by a strong pycnocline. The basic assumptions of this mechanism applied to the data set yield an average drag coefficient of 1 to 2 × 10−3.
A Canadian Arctic Fjord with Some Comparisons to Fjords of the Western Americas
Authors: Lake R. A. , Walker E. R.
Published: April 2011

Aspects of oceanography of d’Iberville Fiord (80°30′N, 80°00′W) are compared to oceanography of west Coast fjords of North and South America. Because of high latitude, hence, cold temperature, d’Iberville Fiord is covered by sea ice for at least 11 mo of each year. An estuarine circulation flows under sea ice except for those Augusts in which sea ice clears. The sea-ice cover and the small tides typical of the northwest Canadian arctic archipelago mean energy inputs to fjord waters are small and currents light. However, water structure in many respects is not dissimilar to that in fjords elsewhere. Effects of a large active glacier debouching into headwaters of d’Iberville Fiord are noted.
Water, Heat, and Salt Transports through Nares Strait, Ellesmere Island
Authors: Sadler H. Eric
Published: April 2011

Data obtained in Nares Strait are used to provide estimates of the transports of water, heat, and salt between the polar ocean and northern Baffin Bay. The annual volume export of water through Nares Strait is 2.1 × 104 km3 ± 30%, which is equivalent to a mean flow of 0.67 × 106 m3∙s−1 and which is about 15% of the total outflow of water from the polar ocean. The annual net heat input into the polar ocean due to the outflow of cold water and ice is found to be 15 × 1019 J ± 50% assuming a reference temperature of −0.1 C. This volume is about 7% of the total advective heat transport into the polar ocean. The mean annual export of salt from the polar ocean is 6.7 × 1014 kg ± 30% or about 6% of the total export. The total transports through the whole Canadian archipelago are estimated and it is shown that they are appreciable fractions of the total exchanges between the polar ocean and the world ocean.
Numerical Model Studies of the Tides Between Vancouver Island and the Mainland Coast
Authors: Crean P. B.
Published: April 2011

An extensive program of numerical model trials, employing joined one- and two-dimensional schemes, and observations, has led to the successful simulation of barotropic tidal propagation in the complex system of channels and inlets between Vancouver Island and the mainland coasts. This work is briefly reviewed. Some results are presented for a 7-day sequence of mixed tides.
Relation of Number of Eggs and Egg Length to Carapace Width in the Brachyuran Crabs Chionoecetes bairdi and C. opilio from the Southeastern Bering Sea and C. opilio from the Gulf of St. Lawrence
Authors: Haynes Evan , Karinen John F. , Watson Jeffrey , Hopson Daniel J.
Published: April 2011

The number of eggs attached to pleopods of Chionoecetes bairdi and C. opilio from the southeastern Bering Sea increased at a rate proportional to about the 3.4 and 2.7 power of carapace width, respectively, but for C. opilio from the Gulf of St. Lawrence it increased to the 4.2 power. The range in carapace width and number of eggs for crabs from the Bering Sea of a given carapace width were considerably greater for C. bairdi than for C. opilio. In the southeastern Bering Sea, the reproductive potential for adult females of C. bairdi with mixed spawning history is approximately 4 times greater than that of C. opilio spawning for the first time. Chionoecetes opilio females with mixed spawning history in the Gulf of St. Lawrence carry more eggs for a given carapace width than first-time spawners from the southeastern Bering Sea. Our data were not sufficient to resolve the question of relative number of eggs for crabs of various ages.
Growth Inhibition Caused by Turbulence in the Toxic Marine Dinoflagellate Gonyaulax excavata
Authors: White A. W.
Published: April 2011

The effects of agitation on growth of Gonyaulax excavata were determined using laboratory cultures. Continuous rotary shaking of cultures at speeds of 125 rpm and greater caused rapid death and disintegration of cells, while shaking at slower speeds caused inhibition of growth rate compared to nonshaken cultures. Also, intermittent shaking, even for as little as 30 min/day, caused growth inhibition. The study suggests that small-scale, oceanic turbulence of sufficient intensity may inhibit growth of individual dinoflagellate cells.
Nutrients, Chlorophyll, and Internal Tides in the St. Lawrence Estuary
Authors: Therriault Jean-Claude , Lacroix Guy
Published: April 2011

Tide-dependent variations of temperature, salinity, dissolved oxygen, phosphate, nitrate, and chlorophyll a support the existence of internal tides (longitudinal and transversal) in the St. Lawrence estuary. Vertical oscillations of the poorly oxygenated and nutrient-rich intermediate and deep waters of the estuary have been documented at the head of the Laurentian Channel, the region in which the internal tides are thought to be generated. Penetration of intermediate waters (high-nutrient and low-oxygen concentrations) beyond the Laurentian Channel associated with the internal tides and linked with an intense mixing process in the upstream region permits the nutrient enrichment of the surface waters and their eventual advection in the seaward direction.
Relationships of Epibiotic Fouling and Mortalities of Eggs of the Dungeness Crab (Cancer magister)
Authors: Fisher William S.
Published: April 2011

This study describes the close association of epibiotic microbial fouling on the eggs of Cancer magister and egg mortalities. Laboratory experiments showed that nutrient enriched sea water increased the number of measurable filaments on the egg surface and increased the number of egg mortalities. Chemotherapeutic treatment of the sea water decreased the number of filaments and mortalities. The use of antibiotics decreased the number of mortalities while the number of filaments steadily increased, suggesting that antibiotic-sensitive, nonfilamentous forms may be substantially responsible for mortalities caused by microbial fouling. Darkness and ultraviolet irradiation of the sea water had no significant effects on filaments or egg mortalities. Both filamentous fouling and egg mortalities described exponential declines with increased depths into the egg masses.
Instar Succession, Vertical Distribution, and Interspecific Competition Among Four Species of Chaoborus
Authors: Carter John C. H. , Kwik Judith K.
Published: April 2011

Of four highly oligotrophic lakes of the Matamek River System, Quebec, Lac à la Croix contains Chaoborus punctipennis and C. trivittatus, Lac Gallienne C. americanus, Lac Randin C. americanus and C. trivittatus, and Lac Méchant C. flavicans and C. trivittatus. The instars are all planktonic except instars I–III of C. trivittatus in Lac à la Croix. All species have a 1-yr life cycle except C. americanus in Lac Gallienne which has a 2-yr cycle. The cycles of C. trivittatus in lacs Randin and Méchant are out of phase by 1 mo or more with those of C. americanus and C. flavicans, respectively. Seasonal increases in length occurred in most instars except those of C. punctipennis in Lac à la Croix. Both species in Lac à la Croix made fairly extensive diurnal migrations but in lacs Gallienne and Méchant all species remained near the surface. Intense competition for food is considered the most likely cause of seasonal or spatial separation of instars of similar size in all lakes.
Crayfish Growth in Lake Tahoe: Effects of Habitat Variation
Authors: Flint R. Warren , Goldman Charles R.
Published: April 2011

The natural history and ecology of the freshwater crayfish Pacifastacus leniusculus was investigated in Lake Tahoe for 1 yr. Growth of individual groups varied between three different transects (I, II, and III). The mean size of carapace of adult crayfish trapped on Transects II and III was greater than those trapped at Transect 1. Linear regression analyses of premolt–postmolt carapace length revealed similar differences. At the onset of sexual maturity females from Transect I were smaller than those from either Transect II or III.Examination of physical and biological parameters in the benthic habitat revealed that food availability, amount of shallow water, and size and area of stone cover influenced the number and size of adult crayfish on each transect. Greater food availability and more extensive stone cover on the lake bottom attracted higher numbers of crayfish to Transect I. The result was overcrowding and competition for food and larger stone cover for larger adults. The effect was a slower growth rate of crayfish on Transect I compared with animals on either of the other transects.
Nutritional Implications of Surface Feeding by Gizzard Shad (Dorosoma cepedianum) on Insect Remains in an Ohio Reservoir
Authors: King Patricia A. , Wissing Thomas E. , De Villez Edward J. , Chimney Michael J. , Randall Jr. William B.
Published: April 2011

On six occasions during July and August 1975, surface feeding by schools of adult gizzard shad (Dorosoma cepedianum) on insect remains was observed in Acton Lake, Ohio. Proteinases in the digestive tract presumably hydrolyze the protein in the insect cuticle. The chitin component of the cuticle also has nutritive value, as significant chitinase activity was demonstrated in extracts of gizzard mucosa, hepatopancreas, and intestinal ceca. Values were comparable to activities observed in other fish species. Chitinolytic system activity was not demonstrated.The mean caloric equivalents of the chironomid and chaoborid exuviae and winged ants in surface debris were 5355, 4363, and 6059 cal/g ash-free dry wt, respectively. Ingestion of insect remains by this forage species could accelerate the return of energy and nutrients in these materials to higher trophic levels.
Fecundity of Balanus balanoides in Passamaquoddy Bay
Authors: Arnold David C.
Published: April 2011

The fecundity of this common intertidal species has been examined at the point of spawning. The development of reproductive potential by the 2+ year-class, rather than by the 1+ year-class, is confirmed. However, a small reproductive potential was found in the largest members of the 1+ year-class. It is suggested that this capacity could be particularly significant under adverse environmental conditions.
Kinetics of Lampricide (TFM, 3-trifluoromethyl-4-nitrophenol) Residues in Model Stream Communities
Authors: Maki Alan W. , Johnson Howard E.
Published: April 2011

The bioconcentration and elimination rates of lamprey larvicide, 14C-TFM (3-trifluoromethyl-4-nitrophenol), were determined for 20 plant and animal species during experimental lamprey control treatments in six indoor model streams. A two-component curve consisting of a rapid initial uptake rate during the first 2 h followed by a reduced linear rate for the remainder of the 24-h exposure best describes the uptake curve for all species examined. The bioconcentration factors (BCF) ranged from 1.1 to 95.5 for animal components and from 0.7 to 12.2 for the plant species. Macroinvertebrate species with soft, relatively permeable integuments accumulate significantly higher residue concentrations (mean BCF = 45.0) than those species with hard chitinized or calcareous exoskeletons (mean BCF = 11.9). Rates of uptake during the linear phase range from 0.36 μg∙g−1∙h−1 for the crayfish Orconectes propinquus to 17.9 μg∙g−1∙h−1 for the caddisfly larvae Brachycentrus americanus.Rates of loss of TFM accumulations correlate with water current and substrate associations. The mean half-life of TFM is 17.8 h for riffle species and 105.9 h for pool-dwelling species. Half-life figures vary from 7.2 h for the crayfish to 5295 h for annelid worms. The longer half-lives observed for several pool species suggest continued accumulation of 14C-labeled residues from the organic matter of the pool bottoms.
Fish Orientation Behavior: An Electronic Device for Studying Simultaneous Responses to Two Variables
Authors: Reynolds William W.
Published: April 2011

An electronic device ("Ichthyotron") is described that permits a fish to simultaneously and independently control (behaviorally regulate) two environmental variables by its movements along two axes, among four chambers. Sample data are given for simultaneous behavioral thermoregulation, light intensity preferences, and locomotor activity rhythms in largemouth bass, (Micropterus salmoides) and smallmouth bass (M. dolomieui).
Gas Bubble Disease. Proceedings of a Workshop held at Richland, Washington, October 8–9, 1974
Authors: Penrose W. R.
Published: April 2011

not available
A Red Tide Caused by the Marine Ciliate Mesodinium rubrum in Passamaquoddy Bay, Including Pigment and Ultrastructure Studies of the Endosymbiont
Authors: White Alan W. , Sheath Robert G. , Hellebust Johan A.
Published: April 2011

A red tide caused by Mesodinium rubrum was observed in Passamaquoddy Bay, New Brunswick, during August 1975. The chlorophyll and phycoerythrin composition and ultrastructure of the endosymbiotic alga are similar to those described for M. rubrum from Ecuador and British Columbia, including the fact that the endosymbionts do not appear to contain a nucleus. Special ultrastructural features are a complete endoplasmic reticulum surrounding symbiont chloroplast, pyrenoid, and starch bodies, ciliate trichocysts with electron-dense and electron-translucent regions, and curious symbiont mitochondria–ciliate macronuclei associations.
Reductions in Biomass and Diversity Resulting from Exposure to Mercury in Artificial Streams
Authors: Sigmon Catherine F. , Kania Henry J. , Beyers R. J.
Published: April 2011

Mercury levels in concentrations similar to those in natural waters contaminated with mercury (0.1 and 1.0 μg/ℓ) caused significant reduction in algal numbers, standing stock, and diversity. Reductions in diversity resulted from a decrease in the evenness of distribution of numbers among species and a decline in the number of species. Although the algal community was affected by mercury ions, the magnitude of change was small at the mercury levels tested and the number of species affected were few. The decline in algal standing crop could indirectly affect other food chain members that possess physiological resistance to the mercury. There was no evidence of direct or indirect impact on the herbivorous or carnivorous midges. The impact on primary producers was not sufficient to be transferred to consumer trophic levels.
Biological Utilization and Regeneration of Silicon in Lake Michigan
Authors: Conway H. L. , Parker J. I. , Yaguchi E. M. , Mellinger D. L.
Published: April 2011

Depth profiles of dissolved reactive silicon and amorphous particulate silicon were made at monthly intervals (April–November 1975) at stations along a southwest transect from Grand Haven, Michigan, to a point approximately in the center of the southern basin of Lake Michigan Biological utilization of reactive silicon occurred prior to stratification in late May or early June. A shift from a 100% diatom-dominated phytoplankton community in spring to ~ 12% diatoms in August was attributed to the low dissolved silicon values observed in the surface water (< 2 μmol/ℓ) during summer. The total amount of biologically active silicon (TBAS) for the lake was found to be approximately 19 μmol/ℓ. Winter values were ~ 2 mol/ℓ amorphous silicon and ~ 17 μmol/ℓ reactive silicon. During the period June–August 80% of TBAS had been utilized by the diatom community, with only 20% remaining as reactive silicon. Greater than 50% of TBAS was lost from the water column during spring and early summer, which was attributed to settling of diatom frustules and the sinking of zooplankton fecal pellets containing frustules. This silicon was subsequently returned, in a soluble form, to the deep water during the fall. The amount of TBAS that was recycled was estimated to be 80–100%. Key words: Lake Michigan, diatoms, recycling, dissolution, limitation, silicon
JPU Theory and the Apotheosis of Simulacra
Authors: Kerr S. R.
Published: April 2011

JPU (just publishable unit) theory was successfully implemented, in utilitarian form, within the same year as its initial, conceptual formulation. This unusual instance of rapid passage from conceptualization to practical realization provides a case study of undoubted significance to the current crop of policymakers for science. Further research is required to determine the processes underlying such rapid relevance, but apparent increases in scientific productivity have already resulted (e.g. this "paper").
Improved Estimates from the Schaefer Production Model: Theoretical Considerations
Authors: Schnute J.
Published: April 2011

The Schaefer production model is converted to a form directly applicable to a data stream of annual fishing efforts and catches. The new version is also stochastic; that is, it allows for unpredictable influences on the fishery. A new method for estimating optimum effort and catch results from this analysis, as well as a way of measuring uncertainty in these estimates. Equations are given for predicting the next annual catch and assigning confidence limits to this prediction. Linear and nonlinear regressions are proposed for this analysis, and the relationship between them is rigorously demonstrated. The linear method leads to estimation formulas simple enough to be applied on a programmable pocket calculator. Key words: Schaefer model, production model, stochastic model, management, fishing effort, catch per unit effort, maximum sustainable yield
Methoxychlor Residue Studies in Caged and Wild Fish from the Athabasca River, Alberta, Following a Single Application of Blackfly Larvicide
Authors: Lockhart W. L. , Metner D. A. , Solomon J.
Published: April 2011

On June 4, 1974, the Athabasca River was treated with methoxychlor for control of blackfly larvae. Pesticide was introduced into the water in a manner calculated to generate a 15-min pulse of treated water containing 300 μg methoxychlor/ℓ. A preliminary experiment with rainbow trout (Salmo gairdneri) indicated that liver or kidney residues of methoxychlor would be suitable for monitoring likely times and places to expect toxic effects on fish in the river. Fish (Salmo gairdneri, Catostomus commersoni, C. catostomus, and Hybopsis gracilis) were caged in order to observe residues and mortality. Caged fish were not killed by methoxychlor but they contained lower liver residues than wild fish of the same species captured near cages. Contaminated wild fish were found upstream of the treatment site after treatment. Residues were below detection limits by June 16. Residue measurements suggested that the most likely times to expect fish poisoning were the 2 wk following treatment and that the most likely places were those river areas extending a few kilometres in both directions from the point of application. Evidence of fish movements and low pesticide residues in caged individuals reduced confidence in residue methods as monitoring tools.
Currents in Johnstone Strait, British Columbia: Supplemental Data on the Vancouver Island Side
Authors: Thomson Richard E.
Published: April 2011

Records from a current meter recently found adrift after 3 yr have been used to complete previously published cross sections of mean flow and tidal currents in Johnstone Strait. The new plots emphasize the cross-channel asymmetry of the estuarine circulation and the large phase lag of the upper layer current relative to the bottom currents for the diurnal (K1) tidal constituent. A recalculation of the net volume transport shows that its magnitude and direction remain undeterminable to the order of ± 103 m3∙s−1. Key words: tidal currents, residual currents, estuarine circulation, Johnstone Strait
Application of Temperature Preference Studies to Environmental Impact Assessment
Authors: Gift James J.
Published: April 2011

Increasing use of laboratory and field temperature preference and avoidance data in power plant siting and environmental impact assessment studies has created a need for evaluation and standardization of methodologies. Relevant considerations and applications are discussed. Key words: temperature, preference, avoidance, power plant siting, environmental impact assessment
Organic Contaminant Residues in Fishes from Nipigon Bay, Lake Superior
Authors: Kaiser Klaus L. E.
Published: April 2011

Three species of fish, caught at various distances from a kraft pulp and paper mill effluent discharge in Nipigon Bay, were analyzed for organic contaminants. Fishes from all sites contained residues of polychlorinated biphenyls and DDE. Most samples were also contaminated with hexachlorobenzene and several samples contained phthalic acid esters.From sampling sites close to the mill discharge, dehydroabietic acid was observed in one extract of each of the three fish species investigated. Two isomers of tetrachlorobenzene and one trichlorobenzene isomer were identified in a longnose sucker (Catostomus catostomus) extract from the vicinity of the mill outfall.
Toward a Relevant Science: Fisheries and Aquatic Scientific Resource Needs in Canada
Authors: Fletcher H. F.
Published: April 2011

Recent shifts in science policy express an increased demand for scientific activities that are relevant — that will enhance the policy and management decision process for the benefit of Canadians. The implications of the increased focus on relevance to the fisheries and aquatic scientific community are discussed and measures to strengthen science in this new operating context are described.It is concluded that an effective scientific effort will increasingly depend on the effectiveness of resource and environmental policy and planning. Arising from this conclusion is the need to develop a more orderly system of transferring scientific knowledge into the decision process. The application of applied systems analysis techniques is discussed as one solution.It is also argued that more effective use of the knowledge of the human and social sciences is imperative to an effective synthesis of natural science knowledge. The synthesis of knowledge leading to policy or management decision alternatives can be subjected to rigorous testing against present scientific understanding or can be systematized within the constraints of existing institutional arrangements. The former describes interdisciplinary research; the latter, planning. Current perceptions of resource and environmental problems point to a need for developing interdisciplinary research programs, for strengthening the planning activity, and for establishing strong links between them. The role of the university community in interdisciplinary research is emphasized and prescriptions for strengthening this role and linkages with government and other client groups are outlined. An increased focus on interdisciplinary research in universities has significant implications in meeting educational needs for the future.