Canadian Journal of Fisheries and Aquatic Sciences

Abstract

Sea lamprey (Petromyzon marinus) entered the upper three Great Lakes in the late 1930s and began making sharp inroads into the fish stocks by the mid-1940s in lakes Huron and Michigan and the mid-1950s in Lake Superior. The first serious attempts to control the parasite began in 1950 with the installation of mechanical barriers along the United States shore of Lake Huron to block spawning runs. Electrical barriers, developed in 1952, were installed in 132 tributaries of the Great Lakes by 1960, but control measures did not become effective until after 1958, when a selective toxicant — the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) — was used to destroy larval lampreys in streams. In the 21 years, 1958–78, 1223 treatments of tributaries of the upper three lakes with TFM were completed in 334 streams — 91 in Canada and 243 in the United States. Evidence of the success of the control program was soon obvious: first by reduced sea lamprey spawning runs as measured by the numbers of adults taken at electrical barriers; second by significant decreases in the incidence of sea lamprey wounds on lake trout (Salvelinus namaycush); and finally by the excellent responses of major fish stocks to sea lamprey control. All three of the upper lakes have large numbers of lake trout, coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), and other salmonids available to the sport fishery and in some areas to the commercial fishing industry. Although the sea lamprey control program has been successful, it is important that emphasis be placed on developing new and innovative methods to reduce the dependence on lampricides. It is expected that a fully integrated program will eventually comprise several methods, including permanent barrier dams on selected streams and the use of sterilants, attractants, repellents, and biological controls, as well as chemical lampricides.Key words: sea lamprey, distribution, abundance, history, predation, integrated controls, Huron, Michigan, Superior