摘要:

ABSTRACTAngling catch data was gathered by a postal questionnaire system from angling clubs holding competitions in three sections of the River Severn over a period of 3 years (1975–78). Angling success was measured as the percentage of anglers taking part that caught fish and as the overall catch rate (g/man/h) of the competing anglers. Species composition of the catch was also recorded.Angling success was closely related to water temperature. Parabolic regressions were fitted to the data. Optimum temperatures for angling success were between 18 and 20°C, except for the Lower Severn section where maximum catch rates were achieved at 14.9°C.Flow had little effect upon angling success until a critical flow was reached, above which success was considerably reduced. Critical flows for the upper, mid and lower sections were approximately 3,000, 5,000 and 10,000 Ml/day, respectively.Species composition of catches within river sections was influenced by water temperature. Some species (bleak, bream, dace and eels) were relatively more abundant in catches made at high temperatures whilst others (chub and roach) predominated at tow temperatures.It is suggested that the percentage of anglers catching fish is the most reliable indicator of angling succ

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00276.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe methods adopted for a tag‐recapture study on the carp population in a South Lancashire lake are described. Fifty‐three percent of carp tagged were recaptured on at least one occasion. Catch frequency data from angling were not observed to deviate significantly from Poisson probabilities indicating that, within any one angling year, the first‐capture experience of a carp did not significantly decrease the risk of its further capture. These findings differ from those of Beukema (1970) with carp in experimental ponds and a possible reason for the difference is suggested. The total population of adult carp in the lake (± standard error) was estimated in 1972 as 452 ± 32 with a corresponding biomass of 1307.44 ± 93.10 kg, or approximately 380.07 ± 27.06 kg per hectare. In the first three weeks of the 1972/73 angling season the rate of exploitation by angling

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00277.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTFreeze‐branding of young trout with metal stamps dipped in liquid nitrogen was investigated for use in experimental work. Good results were obtained when the procedure was standardized as follows: stamp cooled for 30 sec, applied for 4 sec with a pressure of 20–30g. Certain letters were better than others and brands were retained for over 5 months at water temperatures that are normal for tr

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00278.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe design and use of large buoyant seine‐type nets for sampling coarse fish fry are described. These nets have been used over 2 years to take a total of ninety 100 m3and 200 m3quantitative samples from the shallow littoral region of an artificial storage reservoir. The performance of the gear is assessed and the efficiency evaluate

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00279.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Book reviews in this article:Tilapia ‐ a guide to their biology and culture in Africa. JOHN DOMINIC BALARIN assisted by JOHN P. HATTON.A key to the nymphs of the British species of Ephemeroptera with notes on their ecology. T. T. MACAN.Aquaculture. P.J. REA

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00280.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00281.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY