Premium
The distribution and abundance of young (I +–II +) perch, Perca fluviatilis L., in a deep eutrophic lake, England
Author(s) -
Goldspink C. R.
Publication year - 1990
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1990.tb05623.x
Subject(s) - perch , eutrophication , biology , thermocline , predation , fishery , abundance (ecology) , sampling (signal processing) , biomass (ecology) , ecology , fish <actinopterygii> , zooplankton , shoaling and schooling , plankton , oceanography , nutrient , filter (signal processing) , computer science , computer vision , geology
Seasonal changes in the vertical and horizontal distribution of young (I +–II +) perch in Rostherne Mere, a deep (max. depth 31.0 m) eutrophic lake are described using sonar. During the summer (June–August), perch were present within the thermocline (9–14° C) between 7 and 10 m. There was no significant difference between samples during this period, nor was there any evidence of shoaling. From September onwards perch moved into deeper waters. By late winter fish had become patchy in their distribution. Total numbers, during the summer, were estimated to be 988 ha 1 with 95% confidence limits of ±115 (biomass 98.8 kg ha −1 ). Densities (no. m −3 ) fell by over 90% after the autumn overturn. The implications for predators are discussed. Acoustic sampling provides a useful, non‐destructive method of sampling eutrophic lakes on a routine basis. Information obtained is of ecological, behavioural and physiological interest.