Fishery biologist captures larval sea lamprey (FWS photo; Michael Fodale)

The Marquette and Ludington Biological Station Larval Assessment staff recently completed 2008 larval assessment activities in many of the estimated 2,200 U.S. tributaries of the Great Lakes.  A majority of the streams periodically are examined for the presence of sea lampreys.  Beginning in early May and ending in late October, assessments focused in about 215 tributaries and offshore areas of Lakes Superior, Michigan, Huron, Erie and Ontario.  Assessments, using backpack electrofishing gear, primarily determined where and when future control actions will be required.  In particular, the assessments identified streams that need lampricide treatment during 2009 and the effectiveness of past control actions.  Additionally, information was obtained on density, age, length, weight structure and geographic distribution of sea lamprey larvae.  Continuing surveys also were conducted to monitor recruitment and long-term trends of abundance in the St. Marys River through use of deepwater electrofishing gear and global positioning technology.

The Service’s sea lamprey control program continues to work closely with partners to control populations of sea lampreys in tributaries of the Great Lakes to protect the fishery and related economic activities in the basin (an estimated annual benefit of $4-6 billion/year to the region).  The Service delivers a program of integrated sea lamprey control in U.S. waters of the Great Lakes as a contracted agent of the Great Lakes Fishery Commission.