Dreissena population status in nearshore Lake Ontario

摘要: Abstract Dreissenid mussels are ecosystem engineers in the Great Lakes, affecting benthic and water column communities production. We surveyed mussel populations at four Canadian three U.S. locations summer 2008 to update population status examine correlations with data. measured length, density, shell-free dry mass (SFDM), condition index, phosphorus content of both shells tissue. The variables chlorophyll a , turbidity, total (TP) were correlated each other lake-wide, but exhibited only few metrics within seasons or shorelines. Quagga ( Dreissena rostriformis bugensis ) represented ~ 99% community nearshore collections. Mussel length declined west-to-east direction increased depth waters. density water, no difference among sites index concentrations nearshore. There significant declines tissue shell P season mussels, clear patterns mussels. estimated there 9.7 × 10 12 (mean = 3402.9/m 2 Lake Ontario totalling 1.2 × 10 5  mT which could filter entire volume (0–20 m depth = 30.9 km 3 roughly 1 7 days. It appears that has since last large surveys 10 years ago (Canadian nearshore, respectively), however data either slightly supportive of, showed support for, food limitation goby predation as most parsimonious explanation for decline abundance.