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Research article2008Peer reviewed

Salmonid or nonsalmonid lakes: predicting the fate of northern boreal fish communities with hierarchical filters relating to a keystone piscivore

Spens, Johan; Ball, John P.


We determine if lacustrine salmonids show large-scale patterns of coexistence with the keystone predator northern pike (Esox lucius) and test an approach to predict fish communities using coexistence rule set in the context of three hierarchical filters that a species must pass to be present. The mutually exclusive species distribution patterns that we detected among 1029 lakes were repeatedly verified from results of whole-lake interventions with rotenone and introductions. Essentially, pike did not coexist with self-sustaining salmonid populations in lakes. High connectivity to pike (derived from maps) largely predicts the absence of lacustrine salmonids. Our analysis strongly suggests that pike prevented self-sustaining populations of brown trout (Salmo trutta). Arctic char (Salvelinus alpinus), and brook trout (Salvelinus fontinalis) in lakes. High connectivity to pike resulted in nonsalmonid lake fish communities, most often including both European perch (Perca fluviatilis) and roach (Rutilus rutilus). Our analysis suggests that if pike were not present in many boreal lakes where they now dwell, salmonid fish assemblages would prevail, a sharp contrast from the present pike-driven homogenized state with mainly nonsalmonid fish communities.

Published in

Canadian Journal of Fisheries and Aquatic Sciences
2008, Volume: 65, number: 9, pages: 1945-1955