Fish community change in Lake Superior, 1970-2000

• Published in: Canadian journal of fisheries and aquatic sciences 2003-12, Vol.60 (12), p.1552-1574
• Main Authors: Bronte, Charles R, Ebener, Mark P, Schreiner, Donald R, DeVault, David S, Petzold, Michael M, Jensen, Douglas A, Richards, Carl, Lozano, Steven J
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; Applied ecology; Bioenergetics; Biological and medical sciences; Biomass; Comparative analysis; Contaminants; Coregonus artedi; Coregonus artedii; Coregonus clupeaformis; Eutrophication; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fish; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Geological surveys; Habitat utilization; Habitats; Indigenous species; Insecticides; Introduced species; Lakes; Marine; Marine ecosystems; Mortality; Nonnative species; Osmerus mordax; Overfishing; Petromyzon marinus; Petromyzontidae; Pisces; Predators; Prey; Salmon; Salmonidae; Salvelinus namaycush; Species composition; Species extinction; Stable isotopes; Sustainable fisheries; Synecology; Toxaphene; Trophic levels
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f03-136

Changes in Lake Superior's fish community are reviewed from 1970 to 2000. Lake trout (Salvelinus namaycush) and lake whitefish (Coregonus clupeaformis) stocks have increased substantially and may be approaching ancestral states. Lake herring (Coregonus artedi) have also recovered, but under sporadic recruitment. Contaminant levels have declined and are in equilibrium with inputs, but toxaphene levels are higher than in all other Great Lakes. Sea lamprey (Petromyzon marinus) control, harvest limits, and stocking fostered recoveries of lake trout and allowed establishment of small nonnative salmonine populations. Natural reproduction supports most salmonine populations, therefore further stocking is not required. Nonnative salmonines will likely remain minor components of the fish community. Forage biomass has shifted from exotic rainbow smelt (Osmerus mordax) to native species, and high predation may prevent their recovery. Introductions of exotics have increased and threaten the recovering fish community. Agencies have little influence on the abundance of forage fish or the major predator, siscowet lake trout, and must now focus on habitat protection and enhancement in nearshore areas and prevent additional species introductions to further restoration. Persistence of Lake Superior's native deepwater species is in contrast to other Great Lakes where restoration will be difficult in the absence of these ecologically important fishes.