The number of sea lamprey has nearly doubled in western Lake Superior in the past year, according to Minnesota and U.S. wildlife officials.

The eel-like, blood-sucking, fish-killing sea lamprey is becoming a problem across Lake Superior, according to Jessica Richards, U.S. Fish and Wildlife Service marine biologist in Marquette, Mich.

"The agency's overall sea lamprey population estimates jumped 23 percent from 2004 to 2005," she said.

Not only is the number of lamprey up, but the scars they leave on fish are up as well. Sea lamprey scars on big lake trout were up more than 400 percent -- 26.9 scars per 100 trout compared to 6.4 per 100 trout last year, reported the St. Paul (Minn.) Pioneer Press Friday.

So far, the spike in the invasive species hasn't reduced lake trout numbers, but that could change quickly if lampreys aren't brought back under control, state officials said.

Copyright 2005 by United Press International