Food web structure of an Arctic lake (Pulmankijärvi, northern Finland) studied by stable isotope analyses
Year: 2007
Type: dissertation
Abstract: The food web structure in Pulmankijärvi was studied using stable isotope analyses to evaluate the relative importance of littoral and pelagic food sources to a relatively diverse Arctic fish community.European whitefish is the most abundant species in the lake, and three groups were separated based on size and gill raker number.Results from a twosource mixing model indicated that littoral food sources dominated the energy flow to most of the fish populations, but pelagic food sources were essential to the diets of two groups of European whitefish as well as Arctic char.Densely-rakered whitefish are primarily supported by zooplankton, and mysids are probably an important component in the partially pelagic diets of both sparsely-rakered whitefish >100 g and Arctic char.Because sparsely-rakered whitefish aged 5+ to 9+ years are likely the most abundant fish in Pulmankijärvi, pelagic production may be extremely important to the overall fish biomass in this Arctic lake.Comparisons with other Arctic lakes having contrasting fish communities indicate that larger lake size and increased inter-specific competition probably explain the reduced reliance on littoral food sources for Arctic char and brown trout in Pulmankijärvi.
Author: Mark D. Mitchell
Language: English
Topic: Isotope Analysis in Ecology
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W2238228632