Mike Goehle (LGLFRO) and volunteer, Jim Grazio (PADEP) retrieve the bottom trawl during ruffe surveillance at Erie, PA. (Photo: Denise Clay, USFWS)

Denise Clay (LGLFRO) and Amanda Colton (LGLFRO volunteer) sort through a ponar sample for New Zealand mudsnail from a Lake Erie site. (Photo: Mike Goehle, USFWS)

The Lower Great Lakes Fishery Resources Office (LGLFRO) completed and submitted the 2007 lower Great Lakes ruffe surveillance data summary to the Ashland FWCO.  This information will be added to the yearly basin-wide ruffe surveillance report which summarizes data submitted by Service offices in the upper Great Lakes and data from surveys conducted in Canada.  In 2007, ruffe were not detected at any of the lower Great Lakes sites on Lakes Erie or Ontario.  Lake Erie sites sampled in both spring and fall included Toledo, Cleveland, Sandusky, Conneaut, and Ashtabula, OH, Erie, PA, and Buffalo, NY.  On Lake Ontario, the lower portion of the Genesee River in Rochester, NY was sampled. 

Site selection is based on the potential of ruffe to expand their range via ballast water from lake freighters.  Therefore, sites tend to be located near active ship berths and dredged navigable channels.  Taking into consideration the ecological preferences of ruffe, sites are also limited to waters of approximately 3-8 meters in depth with little light penetration and soft substrates.  The primary method of surveillance is a 4.9 meter bottom trawl towed for 7-10 minutes.

In 2007, the LGLFRO utilized the annual ruffe surveillance to look for two additional invaders that have recently arrived in the Great Lakes.  The mysid shrimp, Hemimysis anomala (also known as bloody red shrimp) was identified in the Great Lakes in early 2007.  From our spring ruffe survey sites, several of the fish collected incidentally in ruffe trawls were saved for stomach content identification to look for H. anomala.  The species was not detected in any of the diets of the trawl samples saved.  The LGLFRO also collected ponar samples at each of the spring sites in an attempt to confirm the presence of New Zealand mudsnail (Potamopyrgus antipodarum).  This species has been identified in deeper portions of Lakes Erie and Ontario.  No specimens were detected in our nearshore ponar samples.