ISSN:0002-8487    

DOI:10.1577/00028487.1948.10493256

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1948.10493259

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1948.10493260

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1948.10493261

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1948.10493255

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

The average lengths of lake trout (Cristivomer namaycush) captured in the various Algonquin Park lakes during the decade varied from 13.3 to 24.8 inches and the number captured per 100 boat-hours from 39 to 154. When the average length of fish captured is plotted against number captured per unit effort, all the points fall below a line which begins at a length of 13.3 inches with an availability of 220, rises to an availability of 355 at 15.5 inches, and drops lower as the size increases until at 24 inches the line falls below 100 fish per hour. This line has been taken as the standard for availability of lake trout in Algonquin Park and a fishing index has been proposed which compares each fishery with this standard curve. Certain lakes have shown marked annual fluctuations in size and abundance of lake trout that suggest the progression of major year classes through the fisheries. More detailed examination of the catch statistics indicates that an extremely uneven success of year classes of lake trout appears to be universal in the Algonquin Park lakes.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[19:TLTFIA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

In 1936, a 10.7-acre lake in Otsego County, Michigan, was treated with rotenone to eliminate a population of stunted yellow perch. An attempt to recover the entire population yielded 4,817 stunted perch, 27 trout in poor condition, and four species of minnows. The weight of what was assumed to be the total population was 516 pounds or slightly more than 50 pounds per acre. In 1937, an experimental planting of Montana grayling was made which was not successful owing to unauthorized introduction of bluegills about the same time. In 1941, 5,000 fingerling brook trout were stocked, but proved unable to compete with the rapidly increasing bluegill population and disappeared 4 years later. In 1943, walleyes were introduced in the hope of reducing the bluegill population to a point where survivors could make satisfactory growth.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[36:ROMFFA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Field observations indicated considerable loss of eggs of smallmouth bass and a high incidence of fungus infection in the nests in Cayuga Lake, New York, and tributaries. To investigate the possible effect of temperature changes on embryo survival, several tests were run using constant-temperature facilities at the Cornell University Insectary. In 1945, two trials were run raising the temperature of developing ova from 53° to 77° F., and no eggs were killed. During 1946, eggs developing at 65° F. were transferred at 0, 1, 2, 3 and 4 days following fertilization to 50° and 75° F. None of the eggs was adversely affected. The temperature changes took place within one-half hour. The mean incubation period was determined to vary from about 2 1/4 days at a constant temperature of 75° F. to nearly 10 days at 55° F. The observations presented lead to the conclusion that temperature changes in the ranges indicated are not directly responsible for the death of smallmouth bass embryos.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[43:ROTTSA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

A 0.9-mile section of Back Creek at Glengary, West Virginia, was sprayed by airplane with wettable DDT at a rate of 1 pound per acre. Analysis of the deposit showed that 0.39 pound of DDT per acre was actually laid down on the stream surface. Quantitative bottom samples taken of the insect fauna in the riffles, before and after spraying, showed a survival of about 30 percent at the lower stations.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[48:EOAAAO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Experiments were conducted on the toxicity to fingerling brown trout of DDT when applied in an aqueous suspension, as an emulsion, as a solution in which the DDT is dissolved in a petroleum oil such as kerosene, and finally as as dust. The experiments were conducted at the Cornell University Experimental Hatchery in 15-liter aquaria containing 10 liters of water placed in a trough of running water to maintain a nearly constant temperature. Ten brown trout were used in each aquarium in each experiment. Measure of toxicity was taken as time required for a 50-percent mortality.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[59:ASOTTO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor