Endangered salmon may get help from a
strange source: Blood-sucking, eel-like fish called lampreys.
On Jan. 28 a coalition of environmental groups petitioned
the U.S. Fish and Wildlife Service to protect four species of
lamprey under the Endangered Species Act. Two of the species are
parasitic, latching onto salmon and other ocean-going fish to feed
on blood.
“They are kind of punk-rock fish,”
says Jeff Miller of the Center for Biological Diversity. “But
they are important in the ecology of the stream.”
Ironically, the parasite could be an ace-in-the hole for efforts to
protect the rivers and estuaries where salmon live. A 2001 court
ruling undercut those efforts by concluding that salmon reared in
hatcheries are the same as wild fish. The ruling, which inflates
salmon numbers, could knock some species off the endangered list
— meaning less protection for the rivers where they spawn
(HCN, 10/8/01: Coho salmon lose federal protection). But saving the
lamprey could mean protection for salmon streams from California to
British Columbia.
The environmental coalition asserts
that its push to protect lamprey is not a back-door attempt to save
salmon. Studies show that lamprey have been declining for at least
20 years. River dredging, pollution and other kinds of habitat
degradation limit the fish’s ability to migrate and
reproduce, and dams hinder their spawning — lamprey lack the
strength to swim up ladders designed for salmon.
This article appeared in the print edition of the magazine with the headline Parasite could help save salmon.
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