Silver Chub in Lake Erie: Status, Ecology, and Recovery

Thursday, September 12, 2013: 1:20 PM
Miller (Statehouse Convention Center)
Patrick M. Kocovsky , Lake Erie Biological Station, US Geological Survey, Sandusky, OH
Silver Chub Macrhybopsis storeriana was once an abundant small chub in western Lake Erie.  It is currently listed as a species of special concern in Canada and a recovery plan is being developed.  Catch per effort (CPE) in bottom trawls at three nearshore sites (depth <6m) in western Lake Erie declined sharply in the early 1950s and remained low through the mid-1980s.  Silver Chub CPE increased slightly, but remained comparatively and relatively low, following establishment of dreissenids in the mid-1980s but increased sharply as Round Goby CPE increased in the late-1990s.  Despite the sharp increase, CPE remained well below historical levels.  Diet studies conducted since establishment of dreissenids and Round Goby confirm Silver Chub consume dreissenids.  Silver Chub have pharyngeal teeth and are, thus, potentially capable of crushing small dreissenids.  The fact that Silver Chub CPE did not increase until over a decade after dreissenid establishment but concurrent with the sudden increase in Round Goby CPE suggests a functional link between Silver Chub, Dreissena spp., and Round Goby.