ISSN:0002-8487    

DOI:10.1577/00028487.1940.10493076

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1940.10493080

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1940.10493081

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1940.10493082

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1940.10493074

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

摘要:

A total of 2,902 Lake Michigan fish was tagged and released, 48.8 per cent of which were lake trout and 85 per cent lake trout, lake herring, and whitefish. A total of 388 fish or 13.4 per cent was recaptured. The percentages of returns indicated a tremendous fishing intensity for lake trout, whitefish, and sturgeon. About 81 per cent of the recaptured fish were retaken within a radius of 25 miles from the port of tagging (Port Washington, Wisconsin). Lake trout, rainbow trout, and sturgeon were found to be extensive travelers; lake herring, whitefish, chubs, pilots, and perhaps perch did not migrate so extensively. Lake trout, herring, and whitefish tended to move in a northerly direction, perch in a southerly, and rainbow trout in all easterly, toward the Michigan shore. Sturgeon apparently roam all over the lake. Fifty-three per cent of the recovered lake trout were recaptured within one year of release, 73 per cent within 25 miles from Port Washington. It required three years for the trout to become fairly well scattered throughout the lake. With the attainment of adulthood lake trout moved in all directions from the port of release, although nearly 50 per cent of the adults were retaken within 25 miles from this port. Fish moved across state boundaries. Data are given on the growth and estimated age of the tagged lake trout, rainbow trout, whitefish, and sturgeon. The minimum size limits of lake trout and whitefish on the Great Lakes are economically unsound–they are too low–because they permit the capture of these species at a time of most rapid increase in weight.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1939)69[63:TEWLTW]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

摘要:

In an evaluation of the efficiency of trout culture, the author presents a detailed analysis of complete loss records from 288 individual lots of trout at twenty-two hatcheries in the western United States. Summarized data are given to show the percentage loss of eggs, fry, and fingerlings by progressive one-half inch size groups. The accumulative percentage loss is also included to indicate the losses, under average hatchery conditions, between the egg stage and each successive size-group. These data cover the individual species of trout commonly reared in hatcheries; summarized data are given also for all species combined. A brief discussion of hatchery losses, natural losses, and the cost of artificial propagation is included.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1939)69[85:AEOTC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

摘要:

Pollution problems in California are compared with those of the United States as a whole. The expansion of control activities and the cooperative, technical, and enforcement features of our present program are discussed. The success of a plan correlating technical and enforcement work is emphasized.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1939)69[90:PCIC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

摘要:

In a search for more effective disinfectants to combat parasitic diseases of hatchery fish, the authors report results from a series of experiments designed to determine the toxicity of varying exposures to concentrations of formalin, sodium p-phenolsulphonate, ammonium sulphate, and sodium benzoate. Non-toxic concentrations of these disinfectants were tested, in addition to the usual hatchery methods of salt treatment and hand dipping in copper sulphate and acetic acid solutions, on No. 1 brook trout fingerlings which had been experimentally infected with the protozoan parasite Trichodina sp. (previously known as Cyclochaeta sp.).

ISSN:0002-8487    

DOI:10.1577/1548-8659(1939)69[94:EUTCOT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor

摘要:

Terrace-water ponds are being constructed in Alabama that have as their only source of water supply the “run off” from terraced pastures and crop lands. The water level in the ponds fluctuates, and a maximum of 2 to 4 feet of water is lost by evaporation and seepage during extremely dry weather. A minimum depth of 10 feet in the deepest part of the pond is recommended in order to carry the fish population through dry periods.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1939)69[101:FPITPI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1940

数据来源: Taylor