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Biological characteristics of pikeperch, Sander lucioperca , during spawning migration in a Baltic Bay
Author(s) -
SAULAMO K.,
LAPPALAINEN J.,
LEHTONEN H.
Publication year - 2005
Publication title -
fisheries management and ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 55
eISSN - 1365-2400
pISSN - 0969-997X
DOI - 10.1111/j.1365-2400.2004.00434.x
Subject(s) - fishery , bay , sander , gonadosomatic index , fishing , sex ratio , fish <actinopterygii> , geography , biology , population , fecundity , demography , engineering , archaeology , mechanical engineering , sociology
Protection of pikeperch, Sander lucioperca (L.), during its pre‐spawning migration is a hotly debated issue in the Baltic as fishing regulations to protect these stocks are based on anecdotal information. To improve understanding of pikeperch migration and improve the setting of regulations, fish were sampled with a fyke net and gill nets during the migration period (April to June) at the entrance of a spawning bay, and changes in length, sex ratio and gonadosomatic index (GSI) were analysed. Catches were greatest at the beginning of the period and consisted mainly of mature fish. From the beginning of spawning migration in April to late May, daily mean length of pikeperch decreased and then increased rapidly in early June. Sex ratio was equal at the beginning of migration, but was dominated by males thereafter. Pikeperch caught during June had already spawned.