摘要:

ABSTRACTData are presented on the growth of an artificially stocked population of common carp,Cyprinus carpioL. in a South Lancashire rod and line lake fishery. The fish could not be aged from their scales and methods are described for the analysis of directly measured annual growth increments for tagged fish of unknown age in three size classes. Mean growth in weight for carp in the 454–2268 g (1–5 lb) and 2268–4536 g (5–10 lb) size classes was 0.23 and 0.19 kg year−1; mean annual length increments were 10.8 and 4.4 mm, respectively. Carp>4536 g were observed to lose weight and length at a mean annual rate of 0.17 kg and 3.7 mm. The implication of these results to the stocking policy for the lake are discussed in conjunction with previously reported data on stock density and catchability.Comparisons between June/July length‐weight regressions for carp at the time of tagging and after 1 and 2 years indicated no significant differences. Causes of growth inhibition by tagging reported by other authors are examined and considered to have been eliminated from the current study in which no adverse influence on growth could be detected.The effects of population density, competition with other species, chemical factors, weed growths and angling pressure on the growth rates of the carp are discussed and their implications to the management of the fishery

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1982.tb00031.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTApart from some irregularities reflecting changes in permit costs (1975) and the effects of drought (1976), there were increases in angler‐visits, catch per angler‐visit and number of fish caught during the first 5 years of the fishery. Thereafter, there were about 1000–1500 angler‐visits per season, a mean catch of 1.0–1.2 trout per angler‐visit and an annual catch of 1200–1800 trout. Between 1971 and 1980 the mean weight of the fish caught fell from 472 to 349 g.During the period 1976–1980 the mean catch per angler‐visit was 1.2 fish. This compares favourably with results from a selection of upland and lowland British reservoirs. The mean weight of individual trout caught was 362 kg and this value is typical of both stocked and unstocked upland reservoirs. The mean annual catch during 1976–1980 was about 2 kg ha−1. This is similar to the values observed in other unstocked upland reservoirs. The gross yield from such reservoirs can be increased by stocking but the limited data available suggest that at stocking rates above about 5 kg ha−1the net yield (i.e. weight caught — weight

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1982.tb00032.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThe markings of pike (Esox luciusL.) were found to be specific to individual fish. The subsequent recapture of pike after 2 years of growth, indicated that the markings could be used for the positive identification of specific pike.

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1982.tb00033.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1982.tb00034.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Book reviewed in this articleBright Waters, Bright Fish. By RODERICK HAIG‐BROWN.Man and Fisheries On An Amazon Frontier. Developments in Hydrobiology 4. By MICHAEL GOULDING.Ecology and Ethology of Fishes. Proceedings of the 2nd biennial Symposium on the ethology and behavioral ecology of fishes, held at Normal, Illinois, U.S.A. October 19–22, 1979. Ed. by DAVID L. G. NOAKES and JACK A. WARD.Management of Public Oyster Fisheries By MICHAEL B

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1982.tb00035.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY