Rapport nr 164: Uppföljningsstudie av gösens (Sander lucioperca (L.)) och de allmänna fiskbeståndens förekomst i Ålands inre skärgård
Österlund, Jonas (2022)
Åbo Akademi, Husö biologiska station
Julkaisun pysyvä osoite on
This was a follow up study based on previous survey of fish stocks in the inner archipelago of Åland with special focus on pikeperch (Sander lucioperca (L.)) performed in the year 2011. Pikeperch is a highly valued species both commercially and recreationally. The fishing pressure in Finström municipality, Åland, is high compared to other municipalities in Åland. Thus, it is important to examine the fish stocks in this area. Survey fishing was done using standardized coastal survey nets during the summer of 2022, from July to August. All fish were weighted and measured, while the sex of perch (Perca fluviatilis) and pikeperch was determined. The stomachs and otoliths of pikeperch were collected for diet analyses and age determination. Smaller pikeperch showed an increased abundance while the ratio of mature spawning pikeperch seemed to have been reduced by half. The diet of the pikeperch in the area had changed. Herring (Clupea harengus) went from being an important feeding species to have no part in the diet. Herring was also absent during this survey fishing compared to the last survey fishing in the area. Cyprinids showed a small increase in both abundance and biomass compared to the year 2011. More data is needed to conclude if the results are a trend or coincidence.