ISSN:0002-8487    

DOI:10.1577/00028487.1949.10493267

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10493274

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10493275

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10493276

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1949.10493277

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Since 1884, when commercial fishing first started on Lake of the Woods, the commercial catch and the fish populations have changed markedly. Lake sturgeon (Acipenser fulvescens) which was originally the most important commercial fish is now almost extinct. The lake whitefish (Coregonus clupeaformis) has also shown a striking decline. Intensive commercial fishing was an important factor in the decline of these species. The practical disappearance of other species which were not subject to heavy fishing, the longnose sucker (Catostomus catostomus), goldeye (Amphiodon alosoides), and quillback (Carpiodes cyprinus), however, suggest some basic change in habitat. Destruction of the spawning beds in the Rainy River by pulp-mill wastes was probably the most important of these habitat changes. A correlation was found between the strength of year classes of saugers (Stizostedion canadense) and June rainfall. Recent declines in the population of yellow pikeperch (Stizostedion vitreum) do not appear to be caused by pollution since its effects on the habitat were evident long before declines appeared in the pikeperch catch. Saugers and yellow perch (Perca flavescens) seem to be on the increase. These species compete with the pikeperch for food. During the summer months, the saugers usually occupy deeper waters than the pikeperch but not consistently enough to preclude competition. The present fishing methods are selective and favor the survival of saugers and yellow perch which are not being taken in proportion to their abundance nor being exploited as intensively as the pikeperch. It is recommended that fishing methods be adjusted to permit greater utilization of yellow perch and saugers.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1947)77[13:STITCF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

In spite of extremely heavy expenditures for rearing of hatchery fish, the angling continues to decline. Millions of fish are wasted each year because of lack of facts on how best to utilize properly the product of hatcheries.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1947)77[26:SOTIS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

A decline in gill-net catches of adult yellow pikeperch of the spawning runs and reduced catches by anglers in Spirit Lake, Iowa, during the past several years prompted the Iowa Conservation Commission to estimate the available stock in the lake by a tagging experiment. A total of 550 adult yellow pikeperch was tagged. In a subsequent creel census of fishermen from May 15 to November 1, 1947, 157 tagged fish were recaptured and 8,719 untagged yellow pikeperch were caught. By means of the Peterson formula, the population of adult yellow pikeperch in the lake was calculated to be 30,544 as of May 15, 1947. This appraisal indicated depletion. Management practices were modified to favor return of the yellow pikeperch to its former abundance.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1947)77[32:TPOYPS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Data on the relationship between the total length and weight of the muskellunge, Esox m. masquinongy, based on measurements of 264 fish caught by anglers from Lake St. Clair are presented. The fish ranged in length from 30 to 54 inches and in weight from 6.5 to 37 pounds. The plotting of weights of individual fish against their respective lengths indicated a definite relationship between those measurements. Agreement was close between the data on muskellunge from Lake St. Clair and muskellunge (Esox m. ohiensis) from Chautauqua Lake, New York. Similar data on muskellunge (probably some Esox m. immaculatus and E. m. masquinongy) from scattered inland lakes of Michigan indicated that those fish may be slightly heavier than individuals from Lake St. Clair.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1947)77[42:LROTME]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor

摘要:

Limitations of the electrical-shock method of collecting fish, as commonly used, are reviewed. Among these are the facts that the equipment considered necessary is cumbersome and costly; that the method is effective only on quite narrow, clear-water streams; that effectiveness varies greatly with chemical content of soil and water; and that it is dangerous. Equipment and techniques that overcome these limitations to a greater or lesser extent are described. It has been found that less and more simple gear can be used effectively and safely. Methods of handling equipment which eliminate many time-consuming delays have been developed. Equipment and procedures which are fully satisfactory on wider streams and in turbid waters are described. An electric “seine,” effective in streams 90 to 100 feet wide, has been developed. By employing special techniques, it can be used quite effectively in wider streams. In turbid water the method is less efficient but quite satisfactory sampling of the fish population can be made.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1947)77[49:WAOTEM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1949

数据来源: Taylor