Growth and Survival of Sea Lampreys from Metamorphosis to Spawning in Lake Huron

Abstract

Larval Sea Lampreys Petromyzon marinus live burrowed in stream bottoms and then metamorphose into their parasitic stage. Among larvae that metamorphose in a given year (i.e., parasitic cohort), autumn out-migrants (October–December) to the Laurentian Great Lakes can feed on fish for up to 6 months longer than spring out-migrants (March–May), which overwinter in streams without feeding. We evaluated whether the season of out-migration affected growth or survival of newly metamorphosed Sea Lampreys in Lake Huron. Newly metamorphosed individuals (n = 2,718) from three parasitic cohorts were netted during their out-migration from Black Mallard Creek, Michigan, to Lake Huron during autumn 1997 through spring 2000; each out-migrant was injected with a sequentially numbered coded wire tag and was released back into the creek. After up to 18 months of feeding in the Great Lakes, 224 (8.2%) Sea Lampreys were recaptured (in 1999–2001) as upstream-migrating adults in tributaries to Lakes Huron and Michigan. Recovery rates of autumn and spring out-migrants as adults were 9.4% and 7.8%, respectively, and these rates did not significantly differ. Overwinter feeding (i.e., as parasites) by autumn out-migrants did not produce adult mean sizes greater than those of spring out-migrants. Because we detected no growth or survival differences between autumn and spring out-migrants, the capture of newly metamorphosed Sea Lampreys at any point during their out-migration should provide equal reductions in damage to Great Lakes fisheries. The absence of a difference in growth or survival between autumn and spring out-migrants is an aspect of Sea Lamprey life history that yields resiliency to this invasive parasite and complicates efforts for its control in the Great Lakes.

Received August 2, 2013; accepted October 26, 2013

Published online March 3, 2014

ACKNOWLEDGMENTS

We thank Richard Berryhill, Jeffrey Locke, and Karen Slaght for assistance in netting and tagging the Sea Lamprey out-migrants, and we thank the adult assessment personnel from the Marquette Biological Station (U.S. Fish and Wildlife Service) and the Sea Lamprey Control Centre (Department of Fisheries and Oceans Canada) for trapping and detecting the tagged adult-stage Sea Lampreys. Richard Beamish and several anonymous reviewers provided comments that greatly improved this manuscript. We also thank Wayne Bouffard and Jeff Slade for helpful reviews of an early version of this paper. This article is Contribution Number 1796 of the U.S. Geological Survey, Great Lakes Science Center.