G4 Doctoral dissertation (monograph)
Feeding ecology and behaviour of pikeperch, Sander lucioperca (L.) in boreal lakes (2008)

Keskinen, T. (2008). Feeding ecology and behaviour of pikeperch, Sander lucioperca (L.) in boreal lakes [Doctoral dissertation]. Jyväskylän yliopisto. Jyväskylä studies in biological and environmental science, 190. http://urn.fi/URN:ISBN:978-951-39-3299-2

JYU authors or editors

Publication details

All authors or editors: Keskinen, Tapio

ISBN: 978-951-39-3267-1

Journal or series: Jyväskylä studies in biological and environmental science

ISSN: 1456-9701

Publication year: 2008

Number in series: 190

Number of pages in the book: 54

Publisher: Jyväskylän yliopisto

Publication country: Finland

Publication language: English

Persistent website address: http://urn.fi/URN:ISBN:978-951-39-3299-2

Publication open access: Other way freely accessible online

Publication channel open access: 

Publication is parallel published (JYX): http://urn.fi/URN:ISBN:978-951-39-3299-2

Abstract

Pikeperch is a predatory percid fish living in lakes and coastal areas in Europe. In this thesis, the role of pikeperch as a predator in freshwaters was studied by several methods. Diet and growth of pikeperch with respect to lake characteristics were studied. Smelt and perch were the most important prey species in Finnish lakes. The proportion of roach increased with pikeperch size and with total phosphorus content of a lake. Behaviour of pikeperch in a large boreal lake system was studied by tagging 21 pikeperch with ultrasonic transmitters. These telemetry studies showed that in the Päijänne lake system separate populations occurred, having different migrations and foraging tactics. Pikeperch always preferred the warmest available water. A bioenergetics model for pikeperch based on laboratory experiments was constructed. This bioenergetics model for pikeperch showed good fit in both the laboratory validation and field evaluation and was thus able to predict the food consumption of pikeperch based on the observed growth. The most important input variable in evaluation of uncertainty was activity coefficient, when uncertainty related to other input variables was taken account. The application of the bioenergetics model on a lake scale indicated that the pikeperch population could regulate the perch population after mass removal of fish and thus prevent recovery of the perch population. After intensive fishing, the perch population was dominated by young individuals and predation of pikeperch focused on these individuals. Increasing age of recruitment to the pikeperch fishery from 4 to 6 years doubled consumption by mass. The numbers of perch consumed depends on size-structures in both pikeperch and perch populations. These complex predator-prey interactions in a fish community mean that calculations by a simple model are only rough estimates, but they nevertheless suggest the high potential ability of pikeperch to regulate a perch population.

Keywords: pike-perch

Free keywords: ravinnonkäyttö

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Ministry reporting: Yes

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