摘要:

Scales and data were collected on over 3,500 Clear Lake yellow bass in 1941–1943, and 1947–1951. In 1941 to 1943 most of the yellow bass in the angler's catch were from the 1939 year class with a few from the 1937 year class. From 1945 to 1951, angling, seining, and gillnetting showed no marked change in the abundance of yellow bass. The 1938, 1940, 1941, 1947, and 1950 year classes contributed few or no fish to the later catches. In 1947 and in 1950 young of the year, were present but apparently few of these fish survived 1 year. The 1939, 1943, 1946, 1948, and 1949 year classes were particularly abundant. Young yellow bass were larger in early July during the years with above normal June air temperatures than during years with cool June temperatures. Most growth in length occurs in the first three years of life. The growth rate decreased from 1937 to 1949 but was more rapid again in 1950 and 1951. In 1947 growth was slow until after July 1, probably as a result of low May and June temperatures. In 1949 little growth took place from July 1 to August 26. In 1948 and 1949 the ponderal index decreased as the season progressed, but this trend was lacking in 1947, 1950, and 1951.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[91:AGACOY]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

Test seining in East Okoboji Lake, Dickinson County, Iowa, in 1940 revealed a large population of rough fish and relatively few game fish. The Iowa Conservation Commission therefore intensified its rough-fish removal activities on the lake. Following several years of this expanded program, significant increases of game fish occurred. These increases are reported in the form of comparative data on catch per unit effort over a period of 12 years, from 1940 to 1951. General observations indicated an improved environment for game fish and an increase in angling success.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[104:TIIGPI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

In theoretical, stabilized fish populations it is shown that maximum yield in weight depends not only on the rates of natural and fishing mortality but also on the nature of growth in weight. Families of yield curves at various combinations of natural and fishing mortality rates are presented for three growth types with point of inflection (A) early in life, (B) about mid-life, and (C) late in life. Maxima appear in all three types but at progressively lower natural mortality rates. The curves are of limited practical value because of the many assumptions which are involved.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[115:TYAVRO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

A program of tagging was carried out in the waters of northern Lake Huron during the fall and winter of 1951–52 in order to supplement the small amount of information available on the movement of sea lampreys during their parasitic phase. A total of 219 parasitic-phase sea lampreys were tagged and released at three localities. Of this number 38 or 17.2 percent were recovered. One tag was recovered near North Manitou Island, Lake Michigan. The remaining 37 were taken in Lake Huron or in streams tributary to that lake. The dispersal of tagged lampreys throughout Lake Huron was wide. Five marked individuals were taken in the southern part of the lake over 150 miles from the point of tagging; 4 of these 5 were captured in Canadian waters. The marked lampreys exhibited no distinct pattern of migration other than a tendency toward a general southeasterly movement in Lake Huron.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[123:MOPSLI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

The purpose of this study was to establish a set of descriptive data which could be used as a reference or a standard in the identification of Bacterium salmonicida, the cause of furunculosis in fish. Since a complete description of B. salmonicida was not available, bacteriologists were not in a position to identify this microorganism in a manner which would meet the rigorous requirements of present-day bacteriology.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[129:AMCDOB]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

A picket barrier with upstream and downstream fish traps was maintained on Sand Creek, a small Oregon Coast stream, during 4 upstream and 3 downstream fish runs (1946–1949), and a smaller trap was operated on a tributary during part of 1947. Two species of trout, coast cutthroat, Salmo clarki clarki Richardson, and steelhead, Salmo gairdneri gairdneri Richardson, and two species of Pacific salmon, the coho salmon, Oncorhynchus kisutch (Walbaum), and the chum salmon, Oncorhynchus keta (Walbaum), made spawning runs during the fall and winter. Downstream migrations of fry and fingerlings, and of spent adult trout, occurred in the spring.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[139:MOSISC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

The young of the white shrimp, Penaeus setiferus (Linnaeus), grow up in estuarine waters the salinity of which is governed by rainfall. The Texas shrimp fishery was well started by 1927. From that time until 1936, catches were relatively low. The fishery underwent a period of growth and high-level catches have been obtained from 1937 to the present. During that period the annual catch in pounds of any one year shows a correlation coefficient of 0.883 with the State's average rainfall of the same year and 2 previous years. Essentially, there were 2 blocks of dry years with a period of wet years between, during which the catches were low and high, respectively. Decline of the white shrimp catch has been sharp with the recent drouth, but it is expected to rise when the drouth breaks. Whether the correlation is directly with salinity per se or some unknown factor governed by salinity is not known.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[151:CORWTT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

Collections of fish were made in Lytle Creek, Clinton County, Ohio, to determine the effect of the partially treated domestic sewage of Wilmington, Ohio, on the fish populations of this stream. The farther the collecting localities were downstream from the plant effluent, the greater were the numbers of species and individuals found. In the septic areas, immediately below the effluent, no fish were observed or collected. Two miles below, in the recovery zone, an average of 1.2 species and 2.2 individuals were taken per collection, with 8 different species represented. Three miles below, also in the recovery zone, 12 species were represented in our collections, with a mean of 1.7 species and 10.8 individuals per collection. In the lower portion of the recovery zone, 4.4 miles below the effluent, 32 species were taken, with a mean of 12.7 species and 197 individuals. In the clean-water zone, 36 species were taken, with a mean of 16.7 species and 294 individuals.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[156:TEOSPO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

The use of rotenone as a means of eradicating fish was studied in 30 ponds distributed throughout Oklahoma, and representing various summer conditions in 1951. In addition, one pond was investigated during the winter.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[166:EORIPR]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor

摘要:

The 1944 year class of lake trout (Salvelinus namaycush) supported a significant sport fishery in South Bay, Manitoulin Island, over the years 1948 to 1950, inclusive, at a time when that species was absent in any numbers in adjoining Lake Huron. The evidence from tagging indicates that this population of lake trout in South Bay was a resident one. These trout reached a length of 20 inches and a weight of 4 pounds as age-group VI. Growth data based on scale reading are presented for age-groups II to VII and confirmed by observations on marked fish. Estimates of the size of the lake trout populations and of the survival of groups marked in different years were made by fin clipping and tagging through the years 1948 to 1951. The population was estimated to consist of some 21,000 fish in 1948 and to have fallen to 600 fish in 1951, the highest mortality rates coming after 1949. Only 3,124 lake trout were recorded as removed by angling during that period and it is believed that the creel census covered more than 90 percent of the fishery. It is suggested that the sea lamprey (Petromyzon marinus) was responsible for the death of most of the remainder of the population and evidence is presented to show that the incidence of scarred fish greatly increased in the years when the estimates of mortality were also high.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1952)82[178:TYCOLT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1953

数据来源: Taylor