The Deadly Kiss

Up the little rivers that feed the Great Lakes, an evil invader was swarming last week by the slithering thousands: the sea lamprey. It looks like a mottled, bluish eel, but instead of a proper mouth it has a round sucker, like the rubber gadget that plumbers use to unplug drains. Inside the rim are rows of small teeth. When a hungry lamprey spies a fish, it darts to the fish's side. The sucker's teeth dig in and get a firm grip. Then the lamprey worries a hole in the fish with a file-like tongue and sucks its blood. Even if the fish survives, it is never quite the same again.

Originally a saltwater hunter, the lamprey long since learned to like fresh water, and established itself in Lake Ontario. In 1921 it appeared in Lake Erie, presumably detouring Niagara Falls via the Welland Canal. Step by step it pioneered the Lakes, reaching Lake St. Clair in 1930 and Lake Michigan in 1936. This year, the first lamprey was caught on the U.S. side of Lake Superior.

Up the Rapids. As lampreys multiply, other fish grow proportionately scarce. First victims are the lake trout, whose small, thin scales cannot resist the lamprey's kiss. In Lake Huron, where lampreys do the most damage, the trout catch last year fell to 41,000 Ibs. (It was 1,750,000 Ibs. in 1939.) Many trout caught showed lamprey scars. When trout get scarce, the lampreys go after rough-scaled perch or even armored sturgeon.

The U.S. Fish & Wildlife Service wants to stamp out lampreys before they do more harm. Dr. John van Oosten of the Great Lakes Division thinks a weak spot may be found in their breeding customs. In late May and June, the lampreys put on their courting colors (mottled brown, yellow and orange) and enter rapid rivers. By clinging with their suckers, they can work their way up foaming rapids or the faces of 40-ft. dams.

When they reach a fast-flowing stream with a gravel bottom, the mated pairs dig a shallow nest by moving the stones with their suckers. Then male and female attach themselves side by side to a large stone. As soon as the eggs are fertilized, the adult lampreys die.

Into the Pan? The tiny larvae that hatch from the eggs bury themselves in mud, their mouths barely exposed. For about five years they lead a quiet, clam-like life, feeding on floating plankton. Then they turn into adolescent lampreys eight inches long, with suckers thirsting for fish blood.

Dr. Van Oosten hopes that this cycle can be interrupted somehow. One scheme: electrically charged barriers across the mouths of streams where lampreys spawn. This scheme may keep the eggs from hatching properly. Another plan: to shock the buried larvae by electrodes thrust into their mud beds. Dr. Van Oosten (and Lake fishermen) hope that Congress will not economize on a $20,000 appropriation promised for these experiments.

Best anti-lamprey measure would be to drum up commercial demand. Lampreys were once a popular delicacy: Henry I of England is reputed to have died from a surfeit of them. Dr. Van Oosten is checking a rumor that Italians in Bessemer, Pa. are lamprey enthusiasts. If a market can be found, enterprising Great Lakes fishermen will gladly exterminate the lampreys free of charge.

This file is automatically generated by a robot program, so reader's discretion is required.