Showing papers in "Wsq: Women's Studies Quarterly in 1958"
317 citations
TL;DR: It is shown that temperature, if acting alone, can determine the distribution of fish in laboratory apparatus and that the preferred temperature is considerably higher than the acclimation temperature at low thermal acclimations, but this difference decreases up to the final preferendum, where both coincide.
Abstract: Laboratory studies of preferred temperature with yellow perch (Perca flavescens) are compared with results from 21 other species. These show that temperature, if acting alone, can determine the dis...
220 citations
TL;DR: The yield of stocks, in which reproduction per spawner declines at low levels of abundance, is particularly improved by a close adaptation of fishing to the optimum percentage for each year's stock, the improvement being the greater, the more variable the environment.
Abstract: Using numerical models, effects of environmental variability upon yield were tested for six single-age fish stocks characterized by different kinds and degrees of density-dependent reproduction pot...
191 citations
TL;DR: Eggs of the chum salmon were exposed to various constant levels of dissolved oxygen for a period of seven days and compensated for reduced oxygen availability by reducing the oxygen demand and rate of development, but eggs no longer survive extreme hypoxial conditions.
Abstract: Eggs of the chum salmon (Oncorhynchus keta) were exposed to various constant levels of dissolved oxygen for a period of seven days. The procedure was repeated with fresh egg samples at various deve...
172 citations
164 citations
TL;DR: It is possible that the severe disturbance to acid-base relationships following the large increase of lactic acid liberated from muscle glycogen may be the principal cause of death.
Abstract: Death occurs in fishes under certain circumstances following severe muscular activity. The precise cause of death is not yet known. However, it is possible that the severe disturbance to acid-base ...
159 citations
TL;DR: Experimental fishing of a relatively constant stock showed that the catch per 100 standard trap hauls (index of catchability) was linearly related to temperature, and catchability is shown to be proportional to activity minus a constant.
Abstract: The activity (walking rate) of lobsters acclimated to various temperatures increased from 2 to 10 °C. and from 20 to 25 °C. but was constant between 10 and 20 °C. Lobsters acclimated to low tempera...
130 citations
TL;DR: The cruising speeds of underyearling and yearling sockeye and coho salmon were determined in a rotating annular trough, for acclimation temperatures ranging from 1° to 24 °C as discussed by the authors.
Abstract: The cruising speeds of underyearling and yearling sockeye and coho salmon were determined in a rotating annular trough, for acclimation temperatures ranging from 1° to 24 °C. Variation in swimming ...
117 citations
TL;DR: The coho fry, because of its river habitat, territorial behaviour, low nocturnal activity and smolt transformation, is considered to show behaviour nearest to that of the parental type of the genus, while the pink fry has the most highly specialized sea-going behaviour.
Abstract: The discussion is based on a detailed etiological comparison of four species of juvenile Oncorhynchus—coho, chum, sockeye and pink salmon. Their behaviour is described in terms of five fixed behavi...
107 citations
TL;DR: The literature on the survival of hatchery-reared trout after release in streams is reviewed and the conclusion is reached that survival is poor in lakes and streams where a resident trout population already exists.
Abstract: The literature on the survival of hatchery-reared trout after release in streams is reviewed and the conclusion is reached that survival is poor in lakes and streams where a resident trout population already exists. In streams the deaths of planted trout occur very soon after their release and have been referred to as "delayed mortality". However, a comparison of survivals after planting in occupied and non-occupied streams shows that many of the deaths are not attributable to hatchery-background or transportation methods, but largely to some aspect of competition with resident trout. Some investigations which have sought to measure the relative survivability of wild and hatchery trout have not used resident wild trout and thus a crucial aspect of the competition has been omitted. Investigations at the Alberta Biological Station test stream, Gorge Creek, are described; in these a significant difference in blood lactic acid levels was found between hatchery trout with and without competition from resident ...
90 citations
TL;DR: In the Mark VI model, the standpipe is open during measurements of permeability as mentioned in this paper, and during measurement of groundwater velocity, the colour dilution chamber is completely sealed, colour is introduced and withdrawn through a sphincter valve with a hypodermic syringe.
Abstract: The groundwater standpipe is a length of pipe, pointed at one end, and has a number of perforations near the point. This is driven into the gravel, where the groundwater flows through it. The permeability of the gravel is measured by lowering the level of water inside the standpipe, one inch below the level outside, and measuring the rate of inflow. The apparent velocity through the gravel is measured in terms of the rate of dilution of a colour solution in the standpipe. A colour is introduced, and its rate of dilution determined from successive small samples taken at suitable intervals of time.Velocity data from the earlier models were erratic and the permeability calibration did not include the range encountered in nature. In the Mark VI model, the standpipe is open during measurements of permeability. During measurement of groundwater velocity, the colour dilution chamber is completely sealed, colour is introduced and withdrawn through a sphincter valve with a hypodermic syringe. The solution is stirr...
TL;DR: The relation between stock and numbers of spawners is obscured by annual environmental changes as mentioned in this paper, where stream discharge occurs at the time the spawners are migrating upstream and the time when the eggs are in th...
Abstract: The relation between stock and numbers of spawners is obscured by annual environmental changes. Stream discharge at the time the spawners are migrating upstream, at the time when the eggs are in th...
TL;DR: With increase in size, cod adopted a more varied diet, in which fish and benthic invertebrates became increasingly important, at lengths over 70 cm.
Abstract: Size at maturity, time of spawning, fecundity and food of cod were examined in the southwestern Gulf of St. Lawrence during the summers of 1955 and 1956. In 1955 and 1956 males were 50% mature at 50 and 53 cm., respectively; females, for the same years, were 50% mature at 52 and 57 cm., respectively. The spawning period lasted from May to September, with peak spawning at the end of June. A cod of 51 cm. in length produced 200,000 eggs, while a larger specimen of 140 cm. in length carried 12 million ripening eggs.Small cod, of 11 to 30 cm. in length, selected a diet of pelagic crustaceans, namely mysids, euphausids and amphipods. With increase in size, cod adopted a more varied diet, in which fish and benthic invertebrates became increasingly important. At lengths over 70 cm., pelagic and bottom forms were taken in approximately equal volumes. Herring was the most important fish in the diet of large cod over 50 cm. in length.
TL;DR: Major movements of trout into Ellerslie Brook, Prince Edward Island, were in April, June–July, and November; and out in May and October to early January; some movements were preponderantly in one direction; others involved trout making simultaneous movements up- and downstream.
Abstract: Major movements of trout into Ellerslie Brook, Prince Edward Island, were in April, June–July, and November; and out in May and October to early January. Some movements were preponderantly in one d...
TL;DR: There is a winter-to-summer decline in lethal temperature, and it appears that naturally occurring water temperatures over 23.5 °C.
Abstract: Upper lethal temperatures of scallops are raised 1 °C. by each increase of 5 °C. in acclimation temperature. Acclimation upwards is fairly rapid (average 1.7 °C. per day over part of the range). Loss of acclimation to high temperature is slow, and appears to take as long as 3 months. There is a winter-to-summer decline in lethal temperature. It appears that naturally occurring water temperatures over 23.5 °C. will be lethal to scallops and directly responsible for mortalities. Temperatures over 21 °C. may also be a direct cause of mortalities but only in special circumstances could mortalities occur as a direct result of temperatures below this. In the "sub-lethal" temperature range, sudden temperature changes upward or downward may so reduce scallop mobility as to make them easier prey to enemies. In this way sudden temperature change could be an indirect cause of increased mortality.
TL;DR: The data indicate that a periodicity is exhibited in the size of the muscles of the mature male haddock, the muscles being nearly twice as large during the pre-spawning and spawning period in May and June as they are in October and November.
Abstract: Observations made as early as 1947 and data collected in 1953 to 1954 and 1956 to 1957 indicate that there is considerable variation in the size and appearance of the drumming muscles of the swim-bladder of haddock with fish length, sex, sexual maturity, and season on the Grand Bank and St. Pierre Bank. For haddock of the same length the data indicate that the drumming muscles of mature male haddock are larger than those of immature males and also of immature and mature females of the same length. In addition the data indicate that a periodicity is exhibited in the size of the muscles of the mature male, the muscles being nearly twice as large during the pre-spawning and spawning period in May and June as they are in October and November. This phenomenon does not occur in female haddock, the drumming muscles of which are considerably smaller than those of male fish of the same size and show no variation in size with the season.It is suggested that the difference in size of the drumming muscles of male and...
TL;DR: Tagged halibut recaptures, size and age composition of commercial landings, and differences in rate of growth suggest generally separate stocks in the two regions.
Abstract: Exploratory fishing in the northern Gulf of St. Lawrence in 1945 and 1946 and off western Nova Scotia in 1947 caught 739 halibut, of which 229 were tagged and released. About 590 fish from the comm...
TL;DR: This preliminary study is based on material from 113 specimens from the eastern Canadian Arctic and finds the female increases her length by about 33% in the first year and reaches about 91% of her final length at puberty, at 6 years; these figures are somewhat larger than expected from the growth patterns of other Pinnipedia.
Abstract: This preliminary study is based on material from 113 specimens from the eastern Canadian Arctic. Animals may be aged from the claws up to 9 to 16 years. The male matures at 7 and the female at 6 ye...
TL;DR: A neotype is designated for Lampetra ayresii (Gunther), a species of parasitic river lamprey endemic to western North America that is redescribed on the basis of material from off the Skeena River, British Columbia, to San Francisco Bay, California.
Abstract: Lampetra ayresii (Gunther), a species of parasitic river lamprey endemic to western North America, is redescribed on the basis of material from off the Skeena River, British Columbia, to San Francisco Bay, California. A neotype is designated. Transformed specimens differ from those of the European Lampetra fluviatilis (Linnaeus) in having a larger eye, a longer prebranchial and a shorter branchial region, and possibly a lower second dorsal fin, an acute rather than an obtuse caudal fin, a higher average number of trunk myomeres, and an area of dark pigment on the caudal fin. Ammocoetes differ from those of Lampetra fluviatilis principally in having a higher number of myomeres, a dark caudal spot (which distinguishes them also from ammocoetes of Lampetra planeri (Bloch), the nonparasitic brook lamprey), and an absence of dark pigment on most parts of the head and on the precursor of the tongue. Specimens from Oregon are recorded for the first time. Specimens from Mill Creek, Tehama County, California, show...
TL;DR: In the laboratory, cultured sockeye salmon became well light-adapted in 20–25 minutes, whereas the time for dark-adaptation was of the order of 55–60 minutes; in the Lakelse River, a sample of natural-run sockeye and coho smolts was found to be fully dark- Adapted by about 10:00 P.M. when the light intensity at the water surface was 0.03 foot-candle.
Abstract: The general structure of the Pacific salmon retina is described. Rods, single cones and twin cones constitute the visual cell layer which, together with the dense pigment layer, undergoes photomech...
TL;DR: A study of the problem was undertaken in relation to the oceanographic features of Foxe Basin, andalyses of ice and bottom sediments support the theory that the dirt embedded in the ice is a marine sediment as opposed to wind-blown terrestrial particles.
Abstract: The discoloured appearance of Foxe Basin ice has been a continuous subject of controversy since Baffin described the condition of this ice in 1615. A number of explanations are reviewed and discussed in view of the recent findings of H.M.C.S. Labrador in Foxe Basin.A study of the problem was undertaken in relation to the oceanographic features of Foxe Basin. The results of these surveys have led to a theory of suspension-freezing of bottom sediments during the winter. Analyses of ice and bottom sediments support the theory that the dirt embedded in the ice is a marine sediment as opposed to wind-blown terrestrial particles.
TL;DR: Almost all stomachs of harbour and grey seals at all seasons and in all localities contained P. decipiens, which appeared most frequently in harp seals taken around the Magdalen Islands in April and May.
Abstract: Identifications were made of ascarids collected from 1948 to 1956 from the stomachs of 318 harbour seals (Phoca vitulina), 812 harp seals (P. groenlandica), and 127 grey seals (Halichoerus grypus) killed in several localities along the Atlantic coast of Canada. Porrocaecum and 2 other genera of ascarids, tentatively identified as Anisakis and Contracaecum, were present in each species of seal. All 112 male Porrocaecum that were identified to species were P. decipiens.Almost all stomachs of harbour and grey seals at all seasons and in all localities contained P. decipiens. Considering all localities, the overall average incidence was about 20 adult P. decipiens in harbour seals and about 100 in grey seals.P. decipiens was normally much rarer in the stomachs of harp seals than in the other seals. It appeared most frequently in harp seals taken around the Magdalen Islands in April and May. The incidence of adult P. decipiens was much lower during the breeding season of the seals and during their southward an...
TL;DR: In this paper, the authors have collected data pertinent to the deep warm waters of a three-layer system in the Cabot Strait area of the Laurentian Channel have been collected since 1915.
Abstract: Data pertinent to the deep warm waters of a three-layer system in the Cabot Strait area of the Laurentian Channel have been collected since 1915. Typical temperature–depth curves indicate that the temperature of the deep layer reaches a maximum at about 250 m. which shows little or no seasonal variations. Observations show warming of the deep layer from the 1920's to the 1950's. This upward trend of temperatures is accompanied by an increase in volume of the deep layer. The deep layer consists of a mixture of "Labrador" and "Slope" waters in which the mixing ratio of the components remains fairly constant from year to year. Fluctuations in temperature of "Labrador" water are reflected by a corresponding change in temperature of the deep layer in the Laurentian Channel. The vertical structure of the waters in the lower Laurentian Channel and the transport of the waters in Cabot Strait suggest that in the deep layers, there is a continuing supply of oceanic waters to the Gulf of St. Lawrence.
TL;DR: Results of the physical oceanographic work of the "Calanus" expeditions of 1949–55 are presented in summary, and the winter regime in northern Hudson Bay offers no reason to doubt that a normal vertical exchange...
Abstract: Results of the physical oceanographic work of the "Calanus" expeditions of 1949–55 are presented in summary. Bathymetric maps are given for Ungava Bay, Frobisher Bay and northeast Hudson Bay. Temperature, salinity and density profiles are used to show the direction of flow of water, without dynamic calculations. Temperature–salinity correlation diagrams show the presence of Atlantic water below 100 metres, well developed in Cumberland Sound, less so in Ungava Bay and Hudson Strait (but still present), and very slight in northern Hudson Bay. In Frobisher Bay the entry of Atlantic water, if it occurs, is masked by tidal turbulence. Inversions of density, giving temporary negative stabilities, are recorded at a number of stations, concentrated in the regions of large tidal ranges; association of these inversions with the state of the tide is indicated. Stability conditions of the water in general are presented; the winter regime in northern Hudson Bay offers no reason to doubt that a normal vertical exchange...
TL;DR: The Schumacher and Schnabel estimates of population size are compared, and reasons are given for preferring the Schumachers formula to permit mortality and recruitment in the population.
Abstract: The Schumacher and Schnabel estimates of population size are compared and reasons are given for preferring the Schumacher formula. This formula is extended to permit mortality and recruitment in the population. Confidence limits are provided according to standard regression theory.
TL;DR: It would appear that the trimethylamine value of cod and haddock muscle may be used with certain limitations, as an objective measure of spoilage in support of an organoleptic system of grading these fish.
Abstract: Whole and gutted cod and haddock were divided into three grades of quality by panels of plant foremen and experienced Department of Fisheries personnel. It was found that there was a close correlat...
TL;DR: For age 4 and 5 Skeena sockeye, plots of total production of adults from individual brood years against number of parent spawners gave a reproduction curve with an almost linear ascending limb and ...
Abstract: For age 4 and 5 Skeena sockeye, plots of total production of adults from individual brood years against number of parent spawners gave a reproduction curve with an almost linear ascending limb and ...
TL;DR: Surveys of herring abundance at the juvenile stage provide an index of year-class strength at recruitment, and upon recruitment to the fishery, the relative strength of these three year-classes was comparable to that observed in the Juvenile stage.
Abstract: Population studies were carried out on herring in the juvenile (first year, post-metamorphosis) stage in Barkley Sound in the summers of 1951 to 1954. Their chief objective was to detect and estima...
TL;DR: Fecundity of herring of same body length and the same age was found to be significantly higher in northern British Columbia than in southern, and certain differences in fecundity were attributed to differences in growth rate.
Abstract: The fecundity of Pacific herring was investigated from a collection of 600 ovaries gathered from various localities along the British Columbia coast during the winter and early spring of 1954–55. It was found that fecundity depended mainly on body length and to a lesser extent on age, independently of its effect on body length. Certain differences in fecundity, found between herring from various localities when die relationship of fecundity to body length was considered, were not found when the relationship between fecundity, body length and age was considered. These differences were attributed to differences in growth rate. Fecundity of herring of same body length and the same age was found to be significantly higher in northern British Columbia than in southern.
TL;DR: There is need for re-examination of the bases for some reported climatic temperature–fish productivity relationships because adequate provision does not appear to have been made for changes in the amount of fishing, in economic conditions or in the efficiency of the fishing fleets.
Abstract: A review of the literature suggests need for re-examination of the bases for some reported climatic temperature–fish productivity relationships. In some instances adequate provision does not appear...