Can fish introductions alter nutrient cycles in previously fishless high-latitude lakes?

Abstract

The additional input and enhanced cycling of nutrients derived from introduced fish can be a significant factor altering nutrient dynamics in oligotrophic lakes. To test this, we used a bioenergetic model to estimate the fish-derived nutrient load in Lake Kuutsjärvi, a historically fishless boreal lake of northern Fennoscandia. The lake was selected because of the absence of other anthropogenic stressors, a known stocking history and the possibility of quantitatively estimating the size-structure and biomass of the fish population through a mass removal. Subsequently, we used a mass balance model to compare fish-derived nutrients with other nutrient load pathways. For comparison over longer timescales, we used lake sediment records of diatoms, chlorophyll and carotenoid pigments, C:N ratios and stable isotopes to infer whether fish introduction produced detectable changes in the lake trophic state, primary productivity and terrestrial nutrient input. Based on the nutrient mass balance model, we found that phosphorus and nitrogen derived from fish were 0.46% and 2.2%, respectively, of the total load to the lake, suggesting that fish introduction could not markedly increase the nutrient load. Accordingly, the palaeolimnological record indicated little increase in primary production but instead a shift from pelagic to benthic production after fish introduction.

Dimensions

Altmetric

PlumX Metrics

Downloads

Download data is not yet available.
Published
2016-04-15
Info
Issue
Section
Original Articles
Supporting Agencies
Maj and Tor Nessling foundation
Keywords:
nutrient cycle, bioenergetic model, fish introduction, chlorophyll and carotenoid pigments, diatoms, stable isotopes
Statistics
  • Abstract views: 2971

  • PDF: 1140
  • HTML: 1630
How to Cite
1.
Milardi M, Lappalainen J, McGowan S, Weckström J. Can fish introductions alter nutrient cycles in previously fishless high-latitude lakes?. J Limnol [Internet]. 2016Apr.15 [cited 2020Nov.27];76(1). Available from: https://jlimnol.it/index.php/jlimnol/article/view/jlimnol.2016.1364