75 research outputs found

    Monthly salinity data for the York River plotted by river mile by month

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    This report presents graphs on the mean salinities yearly by five mile intervals upriver from the mouth of the York River, and these are overlaid with 25-year average data for the same month, along with the 95% confidence intervals

    Life history and management of the grayling in interior Alaska

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    Thesis (M.S.) University of Alaska Fairbanks, 1955Field work on the Arctic grayling was conducted from September, 1951, to May, 1953; data on movements, spawning, food habits, sex ratios, and population dynamics were obtained. Returns on 1,222 tagged grayling varied from 0 to 20 per cent with areas. No returns were obtained from 165 fin-clipped fish. Fish entered the streams in the spring as soon as water started flowing, the dates varying from March 15 to May 9, 1952. Spawning in the Little Salcha River during 1952 is believed to have occurred between June 12 and June 16, Of 262 grayling checked for maturity, 18.7 per cent were mature in their fourth summer, 45 per cent in their fifth summer, and all by their sixth summer. Sex ratios obtained for adults varied with areas. The average sex ratio found for all areas was 79 males per 100 fem ales. The rate of growth was determined for grayling from six areas. The average increment for class V fish varied from 2.7 to 4.6 cm. per year. Aquatic insects were the main food organisms taken by grayling. Some terrestrial insects, fish, fish eggs and vegetable, matter were also taken. In view of the findings made in this study, overfishing appears to be the major cause of the decline in the sizes of grayling populations along the highways in the Fairbanks area. A twelve-inch minimum size limit is apparently the best management procedure, although an area closure is advisable for overfished spawning runs

    Estimates of abundance : VIMS small fish trawl survey, York and Rappahannock Rivers, 1955 to 1982

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    This report presents information on catch of iuvenile fish with a 30 ft. semi-ballon trawl in the York and Rappahannock Rivers, and graphically compares those with the commercial landings in Virqinia waters for the years 1955 throuqh part of 1982

    Catch and Value of Various American Crustaceans 1929-1960

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    Occasional reference has been made to the relative magnitude of the catch of the blue crab in waters outside Chesapeake Bay, yet comparisons are not easily made unless data are readily available. Both parallel and opposite trends in catch have been observed. These could be reflections of the amount of fishing effort or the size of the crab stocks. Comparable records of other crustacean fisheries are often of interest. Compilations are given here of data on crabs, shrimp and lobsters originally published in Fishery Industries of the United States and Fishery Statistics of the United States

    Catch and Value of the Chesapeake Bay Blue Crab 1880 -1960

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    The aim of this report is to compile in a compact form for ready reference numerous data pertinent to the blue crab fisheries of Virginia and Maryland. The need for such a compilation became evident when an attempt was made to evaluate the usefulness of those data as indices of past abundance, and it was realized that many publications had to be referred to in order to cover the field even partially
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