Showing papers in "Wsq: Women's Studies Quarterly in 1963"
TL;DR: It is shown that Bělehradek's temperature function gives a close fit to size and development rate of several species of zooplankters growing in adequate food supply, although conclusions do not depend on the theoretical content of this equation.
Abstract: Existing theories of the adaptive value of vertical migration are examined and found wanting. Adult size and generation length are negative functions of temperature. It is shown that Bělehradek's t...
555 citations
TL;DR: Measurements of routine and standard rates of oxygen consumption of various sized cod at temperatures between 3 and 15 °C revealed a well-marked size effect; small cod consume oxygen at a greater rate per unit weight than do large ones.
Abstract: Measurements of routine and standard rates of oxygen consumption of various sized cod at temperatures between 3 and 15 °C revealed a well-marked size effect; small cod consume oxygen at a greater rate per unit weight than do large ones. Increases in temperature raise oxygen consumption in starved and fed fish. The increase in rate of oxygen consumption of starved fish between 3 and 10° is proportionately greater than that between 10 and 15 °C. Feeding of cod which have previously been starved increases the rate of oxygen consumption by 40–90%. The rate subsides to the starvation level in 4–7 days depending on temperature and amount of food eaten. Handling cod causes them to increase their rate of oxygen consumption; rates return to normal levels in 3–5 hours. Crowding reduces the rate of oxygen consumption apparently by reducing the space for movement and thus restricting activity. Reducing the ambient oxygen from about 10 to 3 mg/l lowers the rate of oxygen consumption slightly, but the respiratory volum...
179 citations
TL;DR: There were sufficient data from 1955 through 1958 to prepare composite charts of salinity, temperature, dissolved oxygen and transparency of the near-surface waters in the Subarctic Region from Asia to America, and the principal features of structure of the properties have been shown.
Abstract: All available oceanographic data observed from 1951 through 1958, north of Lat. 35° N in the Pacific Ocean, the Sea of Okhotsk, and the Bering Sea, together with the relevant literature, were exami...
136 citations
TL;DR: Relative magnitudes and rates of change were inversely related to size of specimens contained in the sample, and the values were not significantly different among groups preserved in formaldehyde solutions of fresh or sea water.
Abstract: Sockeye smolts, pink and chum fry, and pink and chum fingerlings (Oncorhynchus) were sequentially weighed and measured when alive and after death in water and after killing and storage in formalin ...
104 citations
TL;DR: Winter flounders occur from Labrador to Georgia and yield large catches off southern New England and this paper relates their distribution and seasonal movements to environmental factors.
Abstract: Winter flounders occur from Labrador to Georgia and yield large catches off southern New England. This paper relates their distribution and seasonal movements to environmental factors.In spring imm...
92 citations
TL;DR: In this article, responses of fish to simplified environmental features, e.g. visual reference points, support against which fish could brace themselves in current, areas of slow water, overhead cover and areas of shade, were studied at three different water velocities.
Abstract: Observations were carried out in February–March and May–June periods during which water temperature ranges were 0.0–0.5 °C and 8.5–12.5 °C, respectively. Responses of fish to structures representing simplified environmental features, e.g. visual reference points, support against which fish could brace themselves in current, areas of slow water, overhead cover and areas of shade, were studied at three different water velocities. Winter and spring responses to illuminated and dark cover and to areas of rocky bottom were compared. Fish associated progressively more with experimental structures as more environmental features were incorporated into them. Degree of association with such structures and with other types of cover was much greater during winter. Degree of association increased with water velocity during both spring and winter. Increasing water velocities modified aggressive behavior. Fish displayed relatively more at low water velocities and nipped more at high velocities. It is possible that the a...
90 citations
TL;DR: Evidence is presented which suggests that the maturation cycle of the gonads may be regulated by the normal seasonal changes of day length, and it is suggested that a stimulative effect of environmental factors is dependent upon maturation of the hypothalamic-hypoph...
Abstract: Brook trout were exposed to photoperiods ranging from 4 to 20 hours per day and were held either at 8.5 °C or at 16°. The average diameter of the ova was used as an index of ovarian development whi...
86 citations
TL;DR: Female Gammarus, were more resistant than males, there was no difference for A. intermedius, and a variable relation in H. azteca, but no difference was found for G. fasciatus, and resistance to high temperature decreased with size.
Abstract: The crustaceans studied were the isopod Asellus intermedius Forbes, and the amphipods Hyalella azteca (Saussure), Gammarus fasciatus Say, and Gammarus pseudolimnaeus Bousfield.Resistance to high te...
77 citations
TL;DR: A population that produces its greatest sustained yield at a high rate of exploitation is then close to a point where recruitment will fall off rapidly if utilization becomes only slightly more intensive, suggesting that any really close approach to the point of optimum yield will usually be too dangerous to be practical.
Abstract: 1. A population which, before exploitation, includes upwards of 12–15 age-groups in appreciable quantities, is very sensitive to fishing. For example, even as little as 5% catch per annum eventuall...
66 citations
TL;DR: A threshold visual sensitivity of about 1/300 that of bright moonlight and an ability to orient at night, with view of the sky only, provide evidence that retinal images may be useful as migratory cues as long as turbidity does not interfere.
Abstract: Past and current research by the Fisheries Research Board of Canada related to olfactory and visual responses in Pacific salmon is reviewed, including comments on some of the sensory and behavioural relations important in migration.An innate ability to perceive highly dilute odours supports the view that olfaction can be instrumental in detecting a distant source, but the problems of following a well directed course indicate likely support from other sensory paths including visual and acoustico–lateralis responses.A threshold visual sensitivity of about 1/300 that of bright moonlight and an ability to orient at night, with view of the sky only, provide evidence that retinal images may be useful as migratory cues as long as turbidity does not interfere.
66 citations
TL;DR: In 9 of the years since 1928 there have midsummer mass mortalities of scallops in the southwestern Gulf of St. Lawrence, there is evidence that sudden, great increases in water temperature som...
Abstract: In 9 of the years since 1928 there have been midsummer mass mortalities of scallops in the southwestern Gulf of St. Lawrence. There is evidence that sudden, great increases in water temperature som...
TL;DR: It was not found that the progeny-per-parent ratios were significantly affected by the fry plantings, and a possible explanation for the periodicity was suggested by a significant correlation between air temperatures at the times suggested.
Abstract: No significant relationship could be found between variations in the level of fry planting and ensuing variations in the level of catch in the long-term statistics of the Lake Ontario whitefish gill-net fishery. An alternate-year planting experiment in which fry were planted in the even-numbered years 1944 through 1954, similarly failed to show a detectable level of contribution of the hatchery fish to the fishery. The supported year-classes averaged larger than those not given hatchery support but this was judged coincidental because of a phasing with an alternate-year periodicity which characterized the catch statistics over the whole series examined, and was present in the six years prior to the start of the alternate-year plantings. Estimates of spawning stock were calculated and it was not found that the progeny-per-parent ratios were significantly affected by the fry plantings.A possible explanation for the periodicity was suggested by a significant correlation between air temperatures at the times ...
TL;DR: Experiments with unialgal cultures of G. tamarensis isolated from the Bay of Fundy provided overwhelming evidence that it is the primary source of toxin in shellfish in this area and the Gulf of St. Lawrence.
Abstract: Seasonal rise in shellfish toxicity in the Bay of Fundy in 1961 was coincident with increased abundance of a marine dinoflagellate, Gonyaulax tamarensis, and the appearance of toxin in plankton extracts. Experiments with unialgal cultures of G. tamarensis isolated from the Bay of Fundy provided overwhelming evidence that it is the primary source of toxin in shellfish in this area and the Gulf of St. Lawrence. G. tamarensis is widely distributed in the North Atlantic and there is evidence of toxic and non-toxic strains of this species.
TL;DR: Generally the Vancouver Island inlets are shorter and shallower than those of the mainland coast and have shallower sills, and the river runoff into the inlets is considerably less than into the mainland ones and has a winter maximum in contrast to the summer maximum on the mainland.
Abstract: Observations of temperature, salinity and dissolved oxygen content in all but one of the inlets of ten or more miles in length along the west coast of Vancouver Island were made by the University of British Columbia in 1959 and some additional observations were made in 1960 and 1961. The data are summarized to provide a general picture of the oceanographic characteristics of fifteen inlets. Attention is drawn to various features, and comparisons are made with the previous data which are available for only five of the inlets here described. Comparisons are also made with inlets in the mainland coast of British Columbia previously described by Pickard in 1961 in the Journal of the Fisheries Research Board of Canada.Generally the Vancouver Island inlets are shorter and shallower than those of the mainland coast and have shallower sills. The river runoff into the inlets is considerably less than into the mainland ones and has a winter maximum in contrast to the summer maximum on the mainland.Surface salinitie...
TL;DR: The consequences of exploitation of either or both of a pair of competing species are examined using the Lotka-Volterra equations and it is observed that harvesting only one species may provide a mistaken underestimate of capacity for sustained yield, and harvesting two species but relating yield to the fishing mortality rate of only one of the two may give a misleading overestimate of further capacity for sustainability.
Abstract: The consequences of exploitation of either or both of a pair of competing species are examined using the Lotka-Volterra equations. The removal of a fixed proportion of a population on an instantane...
TL;DR: It was concluded that DDT entered mainly through the gills from whence it was transported throughout the body via bone circulatory system and was non-toxic, or at least relatively so, to mosquito larvae.
Abstract: Atlantic salmon underyearlings were exposed to 1 ppm DDT-C14 and the amounts of DDT adsorbed to external surfaces and absorbed internally determined separately on the basis of the C14 activity. Fish killed by the exposure contained on the average 5.87 ppm DDT of which almost two-thirds represented absorbed DDT. After only 5 minutes exposure appreciable quantities of DDT were found throughout the body. At all times, up to and including the time to death, high concentrations of DDT were found in the gills, liver, spleen, heart, kidneys, gonads, and swim bladder. Much smaller concentrations occurred in the stomach, intestines, brain and spinal cord. The muscles, bone, and integument contained the least. It was concluded that DDT entered mainly through the gills from whence it was transported throughout the body via bone circulatory system.Bioassays showed that on the average almost two-thirds of the absorbed DDT was non-toxic, or at least relatively so, to mosquito larvae. The adsorbed DDT showed little, if ...
TL;DR: It was concluded from these experiments that stiffening of a fish with the onset of rigor mortis is not due to contraction or tension development of the muscles, but rather to their changing mechanical properties.
Abstract: The superficial red muscle of lingcod (Ophiodon elongatus) was shown to exhibit unique properties of post-mortem contraction and tension development. In comparison with white muscle, rigor contract...
TL;DR: Parr-smolt metamorphosis in yearling Atlantic salmon was accompanied by variations in plasma and tissue electrolyte levels, and in tissue water distribution Plasma chloride declined sharply with t as discussed by the authors.
Abstract: Parr–smolt metamorphosis in yearling Atlantic salmon was accompanied by variations in plasma and tissue electrolyte levels, and in tissue water distribution Plasma chloride declined sharply with t
TL;DR: Fecundity of Grand Bank haddock was investigated and it was found that fecundity increased at a rate proportional to about the fifth power of the body length and to the square of the age, the correlations between feces and length being better than those between age and length.
Abstract: The fecundity of Grand Bank haddock was investigated from 229 specimens collected during the early springs of 1957–61. It was found that fecundity increased at a rate proportional to about the fifth power of the body length and to the square of the age, the correlations between fecundity and length and between fecundity and weight being better than that between fecundity and age. Within any age-group fecundity was found to increase with length. Since the larger fish of an age-group are the first to mature, it is suggested that fecundity of individual fish may be more directly related to the number of times that the fish has spawned than to such parameters as length, weight or age. Certain differences in fecundity, found between the samples of the individual years, are discussed in relation to such environmental conditions as temperature in so far as it determines the degree of haddock concentration (thus affecting the food supply) at certain times which are probably critical during the early development a...
TL;DR: Techniques of estimating population size, level of fishing, and the degree of dependence of fishing success on environmental factors are examined on the basis of tagging, catch and effort data as well as to aggregations of lobsters and fishing.
Abstract: Techniques of estimating population size, level of fishing, and the degree of dependence of fishing success on environmental factors are examined on the basis of tagging, catch and effort data. A new method is developed to estimate population size from catch, effort, and temperature data when the catchability varies with temperature.The methods of estimation discussed are applied to data collected from a number of lobster fisheries on Canada's Atlantic coast. Analysis confirms a relationship between the catchability of lobsters and bottom temperature. Differences in this relationship are found between areas and between tagged and untagged lobsters within areas. It is suggested that these differences are attributable to the differences in densities as well as to aggregations of lobsters and fishing. The effect of these aggregations on population size estimates is considered.Calculated average catchabilities at comparable temperatures are different for different areas. These differences are correlated with ...
TL;DR: The seaward migration of sockeye salmon smolts through the Babine Lake system to its outlet is examined by extensive tagging, direct observations and experimental orientation tests, suggesting a common triggering stimulus.
Abstract: The seaward migration of sockeye salmon smolts through the Babine Lake system to its outlet is examined by extensive tagging, direct observations and experimental orientation tests. The migration appears to be a well-oriented, non-random movement; it apparently commences from all lake regions at about the same time, suggesting a common triggering stimulus. When migrating, the smolts swim at a speed of 0.65 to 1.0 feet per second. The migration appears to take place primarily at near-surface depths; diurnally, most of the migration activity appears centered around the evening dusk period. There is a consistent increase in rate of travel as the season progresses; in large part this appears a result of increasing migration drive. Orientation tests with a view of only the sky show the smolts capable of time-compensated orientation in relation to celestial phenomena, and such tests at various points along the migration route show the preferred direction of smolts to correspond with the direction of most direct...
TL;DR: Roccus americanus (Gmelin) has become part of the Lake Ontario–St Lawrence River fauna, originating from populations in Upper New York State, and a review of the morphological distinctions of related species is included.
Abstract: Roccus americanus (Gmelin) has become part of the Lake Ontario–St. Lawrence River fauna, originating from populations in Upper New York State. The time required for the species to spread through the lower Great Lakes is discussed and summarized. A review of the morphological distinctions of related species is included.
TL;DR: In this paper, the authors compared the number of lateral plates, dorsal spines, and gill rakers in Pungitius pungittius from 132 North American localities.
Abstract: Ventral spine length and the number of lateral plates, dorsal spines, and gill rakers in Pungitius pungitius from 132 North American localities were compared. The number of lateral plates is consistently high in populations from tidal waters, and low in inland populations. Geographic variation in the number of dorsal spines and gill rakers suggest two allopatric forms of P. pungitius in North America. A Bering form ranges from Alaska along the arctic coasts of Canada, and a Mississippi form ranges from the Great Lakes to the Mackenzie River. Two glacial refugia are hypothesised to explain the origin and present distribution of these forms.
TL;DR: The dose–response relationship of 2-phenoxyethanol, as a general anaesthetic, in adult sockeye salmon has been investigated and the therapeutic ratio was more than 5, indicating that the margin of safety was increased by the decrease in temperature.
Abstract: The dose–response relationship of 2-phenoxyethanol, as a general anaesthetic, in adult sockeye salmon (Oncorhynchus nerka) has been investigated. At 11 °C the effective dose (ED50) and lethal dose (LD50) were approximately 43 and 130 ml/100 Imperial gal, respectively. The therapeutic ratio was more than 3, indicating a good margin of safety. At a lowered aquarium temperature of 4 °C the anaesthetic effects of 2-phenoxyethanol were potentiated. ED50 and LD50 at this temperature were approximately 25 and 130 ml/100 gal of water, respectively. The therapeutic ratio was more than 5, indicating that the margin of safety was increased by the decrease in temperature.
TL;DR: Age, growth and food habits of leopard dace in the lower Fraser River are described, and Laboratory experiments in a stream tank demonstrate a strong current preference in longnose dace fry, yearlings and adults.
Abstract: Age, growth and food habits of leopard dace (Rhinichthys falcatus) in the lower Fraser River are described. Although recently emerged leopard dace and longnose dace (Rhinichthys cataractae) occur t...
TL;DR: Adult sockeye salmon (Oncorhynchus nerka) captured during their spawning migration to Great Central Lake, British Columbia, show a consistent response in the laboratory to water taken from the outlet of the lake.
Abstract: Adult sockeye salmon (Oncorhynchus nerka) captured during their spawning migration to Great Central Lake, British Columbia, show a consistent response in the laboratory to water taken from the outlet of the lake. The specificity of this response has been confirmed and the responses to water from streams feeding Great Central Lake have been determined. A portion at least of the stimulatory material is volatile and can be retained in a cold trap. Concentration of the active factor has been achieved by a freezing-out technique.
TL;DR: Body form, colouration and life cycle show no differences from minke whales of European seas, and there is some evidence that many calves may remain in summer in more southerly waters.
Abstract: Minke whales Balaenoptera acutorostrata support a shore-based fishery in eastern Newfoundland. The appearance of minke whales here parallels the spawning concentration of capelin (Mallotus villosus) and lasts from late May to late July, the whales eating chiefly capelin with some cod and herring and other organisms. Summer distribution extends north to Ungava Bay. A return migration is not noted in Trinity Bay before catching ends in late October but reports from the Labrador coast indicate that many whales pass through just before freeze-up in November or December. The catch in Newfoundland consists mainly of large mature animals, and there is some evidence that many calves may remain in summer in more southerly waters. Body form, colouration and life cycle show no differences from minke whales of European seas. Ear plugs were rarely found to show readable growth layers in minke whales.
TL;DR: The average straight line distance between release and recapture points of 253 tagged lobsters free 10 to 12 months was 7.3 nautical miles (13.5 km), and survival over a 10-month period was estimated to be 76.4%.
Abstract: The average straight line distance between release and recapture points of 253 tagged lobsters free 10 to 12 months was 7.3 nautical miles (13.5 km). Carapace-length growth increments per moult among 870 punch-marked lobsters recovered from the fishing grounds were independent of size and averaged 0.47 inches (11.9 mm) for males and 0.42 inches (10.7 mm) for females. Weight increments per moult varied from 4.0 to 7.5 ounces (113–213 g) for males and from 3.3 to 5.4 ounces (94–153 g) for females. Of the males, 17.8% moulted twice; of the females, 7.4%. Survival over a 10-month period was estimated to be 76.4%.
TL;DR: It was concluded that, until statistically significant samples are obtained over the burbot's range, there is insufficient evidence for rearing burbot in Heming Lake.
Abstract: Vital statistics on the burbot, Lota lota, of Heming Lake, Manitoba were collected over a period of several years. Age, weight and length data are presented. The maximum age of fish in the sample w...
TL;DR: Sampling aboard northern New Brunswick draggers from 1956 to 1961 shows a substantial reduction in the percentage by numbers and by weight of the catch of cod discarded at sea, and large-mesh nets which became effective in 1957 and reduction in sizes retained for landing are mainly responsible.
Abstract: Sampling aboard northern New Brunswick draggers from 1956 to 1961 shows a substantial reduction in the percentage by numbers and by weight of the catch of cod discarded at sea. The total numbers of cod discarded in the southwestern Gulf of St. Lawrence, which amounted to about 7 million in 1956, have been reduced to an estimated 1 million in 1961. Two factors are mainly responsible for this reduction: large-mesh nets which, following an ICNAF recommendation, became effective in 1957, and reduction in sizes retained for landing. The mesh effect is believed to be 1.3 times greater than the cull effect in reducing cod discards in 1961. Discards of American plaice have increased during the same period, due to larger recruitment of young year classes. Discards of species other than cod and plaice are negligible because they are only a small part of the catch. Survival experiments show that most cod and plaice are dead when returned to the sea. The use of large-mesh codends may result in long-term increase in t...