摘要:

A survey of 343 persons filing doctoral dissertations in fisheries and allied subjects from 1934 to 1949 indicates that 114 are now engaged in fisheries research and teaching. Slightly over half of the 343 are now teaching in colleges and 37 are training future fisheries biologists.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[1:WBOTPI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

Fish population estimates, using trap nets in the Petersen mark-and-recapture procedure, were made during 1948, 1949, and 1950 on Sugarloaf Lake in Washtenaw County and during 1950 on Fife Lake in Grand Traverse County, Michigan. The nets were of two sizes: 3-foot and 6-foot. The lake acreages are 180 and 575, respectively. The important fish species were bluegill, pumpkinseed sunfish, yellow perch, largemouth bass, smallmouth bass, black crappie, northern pike, yellow and brown bullheads, and warmouth. The study was limited to fish over 6 inches in length.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[4:EOFPIM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

Two experiments were conducted between October 4, 1948, and October 25, 1949, at the State Fish Hatchery at Marquette, Michigan, to determine the effect of predation on fin-clipped lake trout, Cristivomer n. namaycush [Walbaum], fingerlings. One experiment involved 4,000 unmarked fish and 4,000 clipped fish confined in the presence of adult brook trout, brown trout, rainbow trout, and lake trout.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[17:TMAGOM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

Gorge Creek, a typical small mountain trout stream in southwestern Alberta, was divided by fish-tight screens into two sections, each about three-quarter miles in length. The number of native trout in these was determined by marking and recapture. One section was left as a control. Into the other, 199 3-year-old and 201 2-year-old hatchery-reared cutthroat trout were liberated. Each of the planted trout was weighed and given a numbered Petersen tag before planting. Fish that died were removed daily and weighed. Daily angling was carried on to recapture, weigh, and again release as many as possible. One-third of the 3-year-old fish died, mainly in the first 2 weeks following planting. All lost weight for 40 days, apparently through inability to compete with the native population. By fall (about 100 days after planting) the survivors had regained their planted weights. All, or nearly all, of the 2-year-old fish died, apparently from a combination of shock and starvation. The native trout in the experimental section gained weight all summer and, by fall, were in as good condition as the native trout in the control section.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[35:SOHCTI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

In 1948 and 1949, 1,000 fingerling brook trout of a wild strain and 4,500 fingerlings of a hatchery-developed strain were stocked in Stillwater Pond, a 55-acre pond in Putnam County, New York. All fingerlings were fin-clipped for recognition. Returns from plantings in both years followed similar patterns. Yields from the wild strain were disproportionately low in the first season after planting and disproportionately high in the second season. Field observations indicated that individuals of the two groups were consistently different in appearance and generally could be separated by characteristics of body shape and color. Length-weight data, expressed as condition factors, illustrate morphological differences in trout of the two groups after they had been in the pond for 18 months. Angling returns indicate that better angler satisfaction may be obtained here from stocking trout of both strains together than from stocking either one alone. It is concluded that differences in these two strains of trout as exhibited in this situation are hereditary (racial) and are of sufficient magnitude to be important in management of a brook trout fishery.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[43:RFSBTO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

The management of trout fishing in the National Forests of Virginia, North Carolina, Tennessee, and Georgia is a cooperative effort with Forest Service, the States, and Fish and Wildlife Service participating. The States execute the management programs, provide protection to the resource, operate creel checking stations where these are a part of the program, and sell the special permits. The Forest Service provides the general land management and maintains physical structures on the areas, such as rearing pools, checking stations, and residences for caretakers. Trout for stocking streams are provided by the States and the Fish and Wildlife Service.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[53:MOTWIT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

Two shockers, one powered with a 500-watt, 110-volt, 60-cycle alternating current generator, the other with a 2,500-watt, 230-volt, direct current unit, were compared in two blocked-off sections of Spring Brook, Kalamazoo County, Michigan. An indication of the efficiency of the D.C. unit in recovering marked fish from extremely turbid water was obtained in an unblocked section of Wilder Creek, Calhoun County, Michigan, where the use of the A. C. machine was impracticable. In one Spring Brook section, the fish were shocked, marked, and recovered first with the A. C. unit and then with the D. C. The procedure on the other section was similar except that D. C. was used first.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[63:AMOTEO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

This paper reports results of the first year's tagging experiment on black or striped mullet, Mugil cephalus, carried on by the Marine Laboratory of the University of Miami on behalf of the Florida State Board of Conservation. Mullet support the most important commercial fishery in Florida with average annual landings from 1939 to 1949 of 39,000,000 pounds. Part of this catch is silver mullet, M. curema, but most of it is black mullet, M. cephalus. Mullet were tagged with Petersen tags at 12 locations on the Florida west coast, from Naples to Pensacola. A total of 1,050 tagged fish were released the first year. The total recovery of tags was 26.5 percent, and the maximum recovery for one location was 50 percent. A higher return was made by the fishery from Apalachicola west to Pensacola (37.0 percent) than from St. Marks south to Naples (20.6 percent). This result suggests that there is a more intense fishery in the northwestern part of the state. Most tagged mullet were recaptured within comparatively short distances from the place of tagging, 89.8 percent having travelled not more than 20 miles. The longest migration was 150 miles. A slightly increased tendency to migrate greater distances was shown by fish free the longest period of time, and by fish at large over the winter spawning period. Over 85 percent of fish free during spawning were recaptured within 20 miles of the tagging locality. Doubt is cast by these results on the popular view that Florida mullet undergo extensive migrations. The high rate of return of tags suggests an intense fishery.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[69:ROTFYT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

In 1949 and 1950, a study of shad spawning areas by collecting eggs in plankton nets was undertaken in six Virginia rivers. The areas of maximum spawning were located in three rivers; some evidence of shad spawning was obtained in the others. The investigation included studies of environmental factors, including bottom topography, tidal currents, salinity, turbidity, and temperature. The time of spawning is described and the apparent natural mortality of eggs reported. The value of egg collections in providing information on time, location, and abundance of eggs is discussed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[78:COSAOS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor

摘要:

Sea lampreys from the Lake Huron basin carried no external parasites and showed a fairly low degree of infection by internal parasites. The material examined represented three life-history stages of the sea lamprey. Recently transformed downstream migrants (215 specimens) harbored only nematodes belonging to the genus Camallanus. The percentage of infection was 2.3. Active feeders from the lake (29 lampreys) revealed the highest degree of parasitism (31.0 percent) with the following parasites present: Echinorhynchus coregoni Linkins; Triaenophorus crassus Forel; and Camallanus sp. Among the 257 sexually mature upstream migrants (14.8 percent infected) Echinorhynchus coregoni and E. leidyi Van Cleave were the most common. Only occasional nematodes and cestodes were found, which fact indicates a failure of the lamprey to carry these parasites to the end of its natural life. Of the parasites observed, only the nematodes gave evidence of serious damage to the host. The study suggests that the role played by parasites in the natural control of the sea lamprey in its new habitat in the upper Great Lakes is of minor importance.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1951)81[94:DAPOTS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1952

数据来源: Taylor