Food composition, habitat use and growth of stocked and native Arctic charr, Salvelinus alpinus, in Lake Muddusjärvi, Finland

• Published in: Fisheries Management and Ecology
• Main Authors: KAHILAINEN, K., LEHTONEN, H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: Arctic; Muddusjärvi; Arctic charr; Northern Finland; Salvelinus alpinus; Subarctic
• Online Access: http://dx.doi.org/10.1046/j.1365-2400.2002.00302.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2400.2002.00302.x; https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2400.2002.00302.x

Habitat use, growth and food composition of native and stocked Arctic charr, Salvelinus alpinus (L.), were studied in the subarctic Lake Muddusjärvi, northern Finland, to investigate reasons for poor stocking success. Samples were collected with pelagic and epibenthic gill nets. Stocked and native charr occurred in similar epibethic habitats, whereas pelagic habitat was avoided. Native charr grew fast after shifting to piscivory. Growth rate of stocked charr was slow because only a small proportion of stocked fish became piscivorous during the first year after stocking. During the first lake year, stocked charr divided into slow‐growing planktivores and fast‐growing piscivores. Piscivorous stocked and native charr consumed only whitefish, Coregonus lavaretus (L.), as their prey. Small‐sized (<10 cm) whitefish were preferred when shifting to piscivory.