The role of parasites in food-web topology and dynamics of subarctic lakes

Food webs depict ecological communities via networks of trophic relationships. Parasites have rarely been included in food-web studies, despite their omnipresence and the fact that parasitism represents the most common consumer strategy among organisms. With a growing awareness of the potential importance of parasites in trophic networks, there has been a comprehensive call for their inclusion in food-web analyses. The project addresses key issues related to the topology and functioning of food webs with special emphasis on the role of parasites, using subarctic lakes as model system. Three main approaches are employed, including i) the establishment and analysis of the detailed structure of a whole-lake food web including parasites, and ii) temporal and iii) spatial investigations of key sub-web interactions between fish predators and prey and their trophically transmitted parasites. The adopted framework facilitates in-depth exploration of the importance of parasites in food webs, including analyses of compartmentalisation and main energy pathways, assessment of the impacts of fish species additions and their potential hitchhiking parasites on food-web structure and dynamics, and an evaluation of the role of fish species composition for parasite transmission and the functioning of the trophic network. A postdoc- and a PhD project are carried out as part of the project.

Project leader: Per-Arne Amundsen

Postdoc: Anna Siwertsson

PhD-student: Jesper A. Kuhn