ISSN:0002-8487    

DOI:10.1577/00028487.1958.10492717

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1958.10492718

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1958.10492729

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1958.10492730

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Silver salmon, Oncorhynchus kisutch (Walbaum), of the 1950 brood year were reared at the Soos Creek Hatchery, State of Washington Department of Fisheries, until January 19, 1952. On that date, approximately 72,000 fingerlings were divided between the State of Washington salmon hatchery on Issaquah Creek and the ponds of the School of Fisheries, University of Washington. After two months of orientation, the two lots of fish were released to migrate to sea on March 18 and 19, 1952.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[13:ROSSOK]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Water drawdowns of 1 1/2 to 2 feet were effected at Fort Randall Reservoir immediately following periods of major carp spawning in 1955, 1956, and 1957. Eggs thus exposed were killed. Predictions of the time of spawning were based on gonadal conditions of mature fish, water temperature and weather forecasts. Major spawning occurred in shallow (less than 1 foot deep) flats during periods of warm, calm weather when open-water temperature first reached 62–68° F. Effectiveness of the drawdowns in limiting carp reproduction was judged by the size of the age class produced each year in comparison to a previous year and to other species sampled by the same methods of spot-poisoning, shoreline seining, gill netting and frame netting. Size of the age class of carp established each year was relatively small. It is concluded that the planned drawdowns were primarily responsible for poor reproduction.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[23:ECOCRT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Disturbance of the predator-prey relationship may result in increased angler success and may sometimes provide an effective management tool. Exceptional harvest of walleyes (Stizostedion vitreum) in Clear Lake, Iowa, in 1951 is perhaps explained by reproductive failure of yellow perch (Perca flavescens) in 1950 and by elimination of young yellow bass (Morone interrupta) through more than normal predation. Stocking of 5 northern pike (Esox lucius) per acre in the fall of 1953 increased the weight of the predator population by about 10 percent In the first 6 weeks of the next fishing season, over 20 percent of the stocked northerns were caught by anglers.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[34:DOTPBA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Bioassays were made on ten organic phosphorus compounds, which are now in use or proposed for use as insecticides, to determine their comparative toxicity to fish. There was a wide range in toxicity of the different compounds with 96 hour TLm(median tolerance limit) values ranging from 0.20 to 121 p.p.m. No relationship was apparent between toxicity and chemical structure. With one exception dilution waters with different characteristics (pH, alkalinity, and hardness) apparently had little or no effect on toxicity. Bluegills were somewhat more sensitive to several of these compounds than fathead minnows. The organic phosphorus compounds were less toxic to fish than many of the chlorinated hydrocarbon insecticides. No definite correlation could be established in the toxicity of organic phosphorus compounds between fish, insects and mammals.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[39:TOOPIT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Data on walleye (Stizostedion v. vitreum) population dynamics and angling statistics from a northwestern Minnesota Lake are presented. Many Point Lake has an area of 1,716 acres, and in years studied (1955–1957) had an average annual fishing pressure of 17 man-hours per acre. The average annual harvest of fish of all species was 7.5 pounds per acre of which about 60 percent was walleyes and pike, (Esox lucius). To study relationships between the walleye population and catch, 3,249 adult walleye were marked with distinguishing fin clips during the three years, and these fish tallied in anglers' catches. By application of appropriate statistics it is concluded that, on the average, 26.8 percent of the adult walleye population was taken by anglers each year. Lots of adult fish from natural causes was found to be about 4 percent per year.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[52:SOAWSF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor

摘要:

Fifty-seven paired photometer and Secchi disc measurements made at 18 stations in Saginaw Bay and Lake Huron support the view that a counter-clockwise current usually occurs in the Bay with more transparent Lake Huron water flowing in along the northwest shore and less transparent Bay water flowing out along the southeast shore. The average percentage transmission of surface light intensity, at the Secchi disc depth, was 14.7 percent. Discrepancies in the relationship of disc readings to percentage transmission of surface light are related to the condition of the sky and sea. It is suggested that these discrepancies can best be explained on the basis of the spectral sensitivity of the human eye and its response to surface glare.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1957)87[73:RBSDRA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1958

数据来源: Taylor