A large unmarked sea lamprey larva from the recapture event on Bark River (Lake Michigan). - FWS photo by Michael Fodale

The Larval Assessment staff at the Marquette Biological Station and researchers from Michigan State University recently completed a mark and recapture larval phase sea lamprey population estimate. 

The estimate was taken in the Bark River (Lake Michigan), as part of an ongoing study to examine a potentially more efficient method to rank sea lamprey producing streams for lampricide treatment. 

The new method of ranking streams incorporates a rapid assessment survey technique rather than the current method that relies heavily on measuring larval habitat and electrofishing habitat plots.  Each method generates a ranked list of streams for lampricide treatment and in a subset of those, mark and recapture estimates are used to compare the accuracy and precision of those stream treatment lists.  The study, which began during 2005, will conclude by 2008 and has the potential to improve sea lamprey control activities and reduce program costs.

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.