Rapport nr 132: Gösens ( Sander lucioperca (L.)) förekomst i Ivarskärsfjärden
ABRAHAMSSON, D. (2012)
ABRAHAMSSON, D.
Åbo Akademi, Husö biologiska station
2012
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This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-12-2699-1
https://urn.fi/URN:ISBN:978-952-12-2699-1
Tiivistelmä
During summer 2011 the bay of Ivarskärsfjärden was surveyed for the occurrence of pikeperch
(Sander lucioperca). This survey was done in order to investigate where the pikeperch spend their time after their breeding season and quantify the fish stock in Ivarskärsfjärden during the summer. Test-fishing was performed with Nordic coastal survey nets from the end of June until the first half of August. The population of pikeperch was not found to have increased from earlier years, despite earlier predictions indicating a change in that direction. There was, however, an indication that larger individuals of pikeperch occur at larger depths than the smaller ones. Regarding the rest of the fish stocks, Ivarskärsfjärden was dominated by perch and cyprinids. A high abundance of cyprinids is a common indicator of eutrophication.
(Sander lucioperca). This survey was done in order to investigate where the pikeperch spend their time after their breeding season and quantify the fish stock in Ivarskärsfjärden during the summer. Test-fishing was performed with Nordic coastal survey nets from the end of June until the first half of August. The population of pikeperch was not found to have increased from earlier years, despite earlier predictions indicating a change in that direction. There was, however, an indication that larger individuals of pikeperch occur at larger depths than the smaller ones. Regarding the rest of the fish stocks, Ivarskärsfjärden was dominated by perch and cyprinids. A high abundance of cyprinids is a common indicator of eutrophication.