Parasite-mediated changes in predation on chum salmon

Event date: Wednesday, February 06, 2013, at 12:00 PM
Location: RW432

Stephanie Peacock, Graduate Student
University of Alberta

Host: Martin Krkosek

ABSTRACT

Parasites have complex ecological dynamics that can mediate other trophic interactions and threaten biodiversity conservation.  In Pacific Canada, parasitic sea lice from farm salmon have been mplicated in the decline of pink and coho salmon populations. However, we found no effect of sea lice on a sympatric salmon species, chum salmon.  We investigated how louse infection and predation may interact to affect chum survival using a mathematical model. Specifically, infection with sea lice may increase predation rates on a preferred prey - pink salmon - as they become easier to catch, and release less desirable prey - chum salmon - from the intense predation that typically occurs in early marine life.  Our results indicate that the ecological context in which host-parasite interactions occur may dampen or even reverse the effects of increased parasitism on the population dynamics of the host.