Diet composition and seasonal feeding patterns of a freshwater ringed seal (Pusa hispida saimensis)
Auttila, M., Sinisalo, T., Valtonen, M., Niemi, M., Viljanen, M., Kurkilahti, M., & Kunnasranta, M. (2015). Diet composition and seasonal feeding patterns of a freshwater ringed seal (Pusa hispida saimensis). Marine Mammal Science, 31(1), 45-65. https://doi.org/10.1111/mms.12133
Published inMarine Mammal Science
© 2014 Society for Marine Mammalogy. This is an author's final draft version of an article whose final and definitive form has been published by Society for Marine Mammalogy (Wiley). Published in this repository with the kind permission of the publisher.
The Saimaa ringed seal (Pusa hispida saimensis) is one of the few freshwater seal populations worldwide. The major conservation issue of this critically endangered population is bycatch mortality. We used digestive tract content and stable isotopes (d13C and d15N) to estimate the diet and seasonal feeding patterns for gaining better understanding of the seals feeding habits and potential conservation implications. The diet was similar across age groups. Altogether 15 fish species were identified and the most important were smelt (Osmerus eperlanus), ruff (Gymnocephalus cernuus), perch (Perca fluviatilis), vendace (Coregonus albula) and cyprinids. The high d15N values suggested that the seals lose weight during winter and spring. Additionally the drop in d15N values indicated that pups start to recover from postweaning stress and gain weight around the age of 6 mo. The isotope values differed regionally, which emphasizes that samples from consumers and prey should be collected from the same regions to improve interpretation of the stable isotopic results. Overall, diet composition suggests minimal to nonexistent competition with commercial or recreational fishing. However, observed weight loss of pups during summer may be related to higher risk of bycatch and this should be taken into account when planning temporal fishing closures. ...
Publication in research information system
MetadataShow full item record
Showing items with similar title or keywords.
It takes time to see the menu from the body: an experiment on stable isotope composition in freshwater crayfishes Jussila, J.; Ruokonen, Timo; Syväranta, Jari; Kokko, H.; Vainikka, A.; Makkonen, J.; Kortet, R. (EDP Sciences; Conseil Superieur de la Peche, 2015)For many applications and ecological studies in which wild individuals are brought to laboratory it would be essential to know accurately how fast novel diet is reflected in composition of different tissues. To study the ...
Pulkkinen, Katja; Aalto, Sanni L.; Nykänen, Hannu (Wiley-Blackwell Publishing, 2016)1) Stable isotopes are widely used for studying trophic relationships, but variation driven by environmental conditions or food availability complicates the interpretation of trophic dynamics. Parasites are ubiquitous and ...
Effect of primary dietary sources and environmental variables on the condition of freshwater pearl mussel (Margaritifera margaritifera) populations Nykänen, Sabrina (2021)Earlier studies have suggested effect of land use on freshwater pearl mussel (FPM) via the detrimental impact of siltation on juvenile mussels, but little is known about its effects through the changes in food quality. ...
Effects of fish community composition on ontogenetic niche shifts of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in subarctic lakes Kangosjärvi, Henna (2021)Ravintoverkkotutkimukset yhdistävät biodiversiteetin sekä ekosysteemien toiminnan ja tarjoavat täten kokonaisvaltaisemman näkökulman suojelubiologisiin tutkimuksiin. Ravintoverkkotutkimuksissa on tärkeä huomioida generalistien ...
Associations between observed patterns of classroom interactions and teacher wellbeing in lower secondary school Virtanen, Tuomo; Vaaland, Grete Sørensen; Ertesvåg, Sigrun K. (Elsevier, 2019)Classroom observations and teacher self-reports were used to examine the relationships between patterns of teacherestudent interactions and the wellbeing of Norwegian lower secondary school teachers. Latent profile ...