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The Status of Benthos in Lake Ontario
Citation:
SCHAROLD, J. V. The Status of Benthos in Lake Ontario. Presented at 52nd Annual Conference on Great Lakes research International Asso. of Great Lakes Research, Toledo, OH, May 18 - 22, 2009.
Impact/Purpose:
To study the status of benthos in Lake Ontario
Description:
The benthic community of Lake Ontario was dominated by an amphipod (Diporeia spp.) prior to the 1990’s. Two dreissenid mussel species D. polymorpha (zebra) and D. bugensis (quagga) were introduced in 1989 and 1991 via ballast water exchange. D. bugensis was observed as deep as 85 m in 1995, indicating the species ability to spread to deep, soft substrate habitats. As dreissenids became established, Diporeia dramatically decreased in abundance. Diporeia has disappeared in the shallowest zone (12-88 m) between 1994 and 2008. Recent surveys in 2003 and 2008 indicate that Diporeia are also disappearing in deeper areas of the lake (>90 m). The loss of Diporeia and the increase of Dreissena have implications on the trophic dynamics of the Lake Ontario benthic zone. Keywords: Benthos, Diporeia, Dreissena