Tag Archives: sea lamprey

Invasion of the body fluid snatchers

Every spring, small worm-like larvae emerge from eggs in shallow riffle areas of brooks and rivers, where they are carried downstream by the current until they reach a point of repose on the bottom, and all but disappear. For four years, they are concealed in the mud, blindly feeding on microscopic plants and animals, sightless and unseen.

Then in just a matter of weeks, a horrifying metamorphosis takes place. The larvae develop eyes and a suction-cup like mouth, lined with concentric rings of jagged teeth, encircling a file-like tongue. If you’ve seen Return of the Jedi, the Great Pit of Carkoon may come to mind. If you haven’t, Google “sarlacc”. Also, really? Drop everything and watch Return of the Jedi. Now.


What lies beneath: After four years living on stream bottoms, sea lamprey transform into blood-sucking parasites in search of aquatic hosts like salmon. But what scares fish biologists working in the Lake Champlain basin is the scale of the sea-lamprey population in the system, not the creature’s gruesome face. Credit: FWS.

It’s the stuff of science fiction, but the vile mouth described above doesn’t belong to an imaginary creature from the fictional planet of Tatooine. It belongs to sea lamprey — parasitic, eel-like fishes that at this moment are emigrating from natal streams in Vermont and New York into Lake Champlain (on planet Earth) in search of an aquatic host. Anything with gills and a heartbeat will do.

When sea lamprey zero in on a target like salmon, “They use that suction-cup mouth to stick to its body, and scrape a hole through its flesh with their tongue,” explained Steve Smith, a Fish Biologist at the U.S. Fish and Wildlife Service Lake Champlain Fish and Wildlife Conservation Office.

“Then, they start sucking out its body fluids,” he said. “Whatever they can get.” Blood, bile, serum, pericardial fluid, you name it.

“In the time they spend in the lake as parasites — which is only about 12 to 18 months — a single lamprey can kill what amounts to 40 lbs of fish.”

The loss of fluids essential for temperature regulation, nutrient transport, digestion, and more, can mean death for a relatively small fish like a walleye or a juvenile salmon. But even a fish with enough heft to withstand multiple lamprey hits may eventually succumb to infection from a resulting wound.


Even if a sea-lamprey hit doesn’t kill a fish immediately, the open wound left behind can become infected, leading to secondary mortality. Credit: FWS

For anyone who sleeps with the lights on after watching a scary movie, it’s a nightmare-inducing scenario. But for a fish biologist, it’s not the parasitism that’s scary; it’s the proportion.

While there is debate as to whether sea lamprey are native to Lake Champlain, or were introduced when the Champlain Canal was built in the 1800s, “Whether they have been here for 10,000 years or not, they are out-scaled for this system,” said Smith.

In some systems, they not only fit the scale, but play an important role in keeping a balance, said Fish Passage Coordinator Madeleine Lyttle. In the Connecticut River basin, adult sea lamprey swim upriver from the Atlantic Ocean to spawn, juveniles head out into the ocean in search of hosts after their metamorphosis, and both forms make valuable ecological contributions by enriching the sediment on the river bottom and providing food for other organisms.

The difference? The sea. “Here, they are landlocked, so Lake Champlain is their ocean,” she explained. “It’s just not a very large area to be feeding from.”

In other words, the other fish that inhabit Lake Champlain have no place to hide. So when efforts to restore native fisheries through coordinated restocking efforts got underway in the 1970s, the young fish became fodder for a sea-lamprey population explosion.

In 1990, the Lake Champlain Fish and Wildlife Collaborative struck back, launching a pilot program to see if they could control the sea lamprey population with temporary barriers designed to keep adults from migrating upstream to spawn, and pesticides designed to kill larval lamprey in natal streams before the dreaded metamorphosis occurred. The results were promising. The wounding rate for lake trout dropped from about 100 wounds for every 100 fish to about 30.

But when the experimental program ended in 1998, lamprey numbers skyrocketed, as did salmon and lake trout mortality. “We saw wounding rates on lake trout back at 100 percent,” said Smith.

Fresh wound from a sea lamprey

Fresh wound from a sea lamprey

It wasn’t just that the lampricide treatments were suspended while the Service completed an in-depth Environmental Impact Statement for the program in accordance with the National Environmental Policy Act (NEPA), it was that the problem had been more extensive than they realized all along. It turns out that unlike salmon, which return to the streams from whence they came to spawn, sea lamprey don’t have a so-called natal bias. When it’s time to spawn, they make their way to the closest stream that smells like larval lamprey.

“For years, the control efforts had targeted areas where lamprey were known to spawn,” said Lyttle. “We thought we were getting a handle on them, but they just went somewhere else.”

So the sea-lamprey team took stock, and laid out a strategic plan for an extensive, integrated, science-based, long-term control program for the Lake Champlain basin.

“They really upped the game,” said Lyttle. Today the Lake Champlain Sea Lamprey Control Program involves a five-step process designed to evaluate and manage sea lamprey from natal stream to grave. Wounding rates are down from about 100 wounds per 100 fish to about 30 for lake trout, and 20 for salmon.

With numbers approaching a level that is proportional to the rest of the system, the sea lamprey problem is starting to seem manageable, and the creatures themselves a little less horrifying.

“They are actually pretty amazing, even just in the fact that they are such an ancient species,” said Lyttle. Sea lamprey have been found in fossil records dating to the Pennsylvanian period. For non-geologists, that pre-dates Jurassic, the park and the period.

“They may sound nasty, but anything is when it’s out of control,” said Lyttle. Like cell division, or zombies.

“Things are much better now that everything is recovering,” she said, pointing out that a range of different species are benefiting from the lamprey control program, from salmon to lake trout to walleye to lake sturgeon, a state-listed endangered species in New York.

The lamprey program, along with complementary and integrated programs in research and assessment, stocking, fish passage restoration, and restoration of wetland and riparian habitats by the Service’s Lake Champlain Fish and Wildlife Conservation Office and their partners are allowing these species to come back.

For fish biologists and scaredy-cats alike, that’s reason to sleep easy tonight.

A white man with short brown hair and a blue shirt stands before some green leaves

A holistic approach to sea lamprey control

Congratulations to Brad Young of the Lake Champlain Fish and Wildlife Resources Office, who on Wednesday was presented the Great Lakes Fishery Commission’s award for outstanding contributions to sea lamprey control: the Vernon C.  Applegate award

A white man with short brown hair and a blue shirt stands before some green leaves

Brad Young’s work in the Great Lakes led to better understanding of how pheromones could be used to control sea lampreys. Credit: USFWS

Brad, a supervisory fish biologist, leads a staff of 6-12 biologists who work to control sea lamprey on Lake Champlain so that native lake trout and landlocked Atlantic salmon can be restored. The award recognized this significant role as well as Brad’s previous work in the Great Lakes.

“Brad takes a holistic approach to sea lamprey control . . . he uses the best science available and manages a top-notch staff such that Lake Champlain has seen marked declines in sea lamprey abundances,” said Bob Lambe, vice-chair of the Great Lakes Fishery Commission and director of the Canada-Ontario Invasive Species Centre.

One of the tools Brad skillfully uses both on and off the job is public outreach.

“Brad understands that personal contacts and good relationships are essential to success,” Bob said.

Sea lampreys are aquatic vertebrates native to the Atlantic Ocean. They look like eels, but unlike eels, they feed on large fish. They can live in both salt and fresh water. Sea lampreys were accidentally introduced into the Great Lakes in the early 20th century through shipping canals — Great Lakes Fishery Commission.

Today we hear from Brad about his work.

Q: What do you like best about your job?
A: Watching my staff succeed and seeing them take pride in their work. 

Part of me really misses doing regular field work, but I now live vicariously through the amazing staff I have and get plenty of satisfaction from seeing them enthused about the accomplishing our shared goals.

A man shows children sea lamprey educational materials

“Brad engages the public directly and shares his passion with fellow lake and fishing enthusiasts,” said Bob Lambe at the Great Lakes Fishery Commission awards ceremony in Montreal. Credit: USFWS

Q: What would you like people to know about the work you do?
A: Our program works to restore the native trout and salmon fishery of Lake Champlain, by controlling sea lamprey.

Sea lamprey control is a means to our end, not our singular focus. We are fish biologists, not exterminators.

Q: You were recently on the Animal Planet’s “Vampires of the Deep” episode of River Monsters. What was that like?
A. We spent many hours with the crew of River Monsters to get them footage for their show.  They couldn’t have been nicer and more gracious. 

The star of the show, Jeremy Wade, was down-to-earth and a pleasure to work with. While the show wasn’t a documentary on what we do, I think it served well to highlight the lake, its fishery, and the how important it is to continue our lamprey control efforts.

Any time we can bring attention to our program, it helps with public visibility and support.

A man with a white shirt, blue jeans and a white ball cap stands next to a cooler and behind a bucket, both filled with lampreys. In the background is a body of water with a small dam.

University of Vermont graduate student Eric Howe (left) collects sea lampreys with Brad. Brad’s leadership has greatly contributed to declines of lamprey in Lake Champlain. Credit: Wayne Bouffard/USFWS

Q: What’s your vision for the future?
A: Our program has succeeded over the last six years by decreasing the lamprey population of Lake Champlain by about 60 percent. 

We continue to find ways to improve our efforts and look to bring the population to an even lower level.

Three men in waders stand on a small spillway before water

Left to right: Brad, Anthony Curtis, and Jeremy Wade  on the set of River Monsters. Credit: USFWS

Best of 2012 8) Controlling invasive species

We’re bringing in the new year with a look back at our milestones for 2012. Check back each day for featured events and activities from across the Northeast!

Invasive species pose some serious threats. They can displace native fish and wildlife and change native habitats, harming fish, wildlife and plant resources. Invasive species can also pose a risk to human health. In 2012, the Service worked to reduce the impacts that invasive species are having across the Northeast Region. A few projects that we worked on this year:

The first collection of hydrilla verticillata in Tonowanda Creek. Credit: USFWS

The first collection of hydrilla verticillata in Tonowanda Creek. Credit: USFWS

In September, staff at the Lower Great Lakes Fish and Wildlife Conservation Office discovered hydrilla verticillata, a highly invasive aquatic plant, in the New York State Canal System in Tonawanda, N.Y. Hydrilla crowds out waterweeds and other essential plants, slows water flow and can clog lakes and rivers, enough to even eliminate swimming or boating. The pest is confirmed within one mile of the Niagara River, and thus the Great Lakes. The extent of its possible impacts to the Great Lakes remains unknown, but monitoring elsewhere suggests the plant can become quite a nuisance in waters up to 25 or 30 feet deep. The Service’s Lower Great Lakes office is leading a rapid assessment team of state and federal agencies to determine the actual reach of the plant in the Tonawanda Creek and Niagara River corridor, which will help establish potential response options.

Galerucella beetles helped control invasive purple loosestrife in seven Northeast states in 2012. Credit: Katrina Scheiner

Galerucella beetles helped control invasive purple loosestrife in seven Northeast states in 2012. Credit: Katrina Scheiner

At the Eastern Massachusetts National Wildlife Refuge Complex, biologists reared between 17,000 and 33,000 Galerucella beetles to control purple loosestrife (Lythrum salicaria), an invasive wetland plant. The beetles feed on the leaves of purple loosestrife and reduce the growth and reproduction of the invasive plant. Purple loosestrife can lead to a decrease in plant diversity, resulting in a loss of wildlife diversity. Working with state partners and other organizations, Galerucella beetles were also released in six other Northeast states, including New Jersey, where the beetles were released in bog turtle wetlands.

Sea lamprey wound on an Atlantic salmon.

Sea lamprey wound on an Atlantic salmon.

The sea lamprey (Petromyzon marinus) is a predatory fish that attaches to a host fish and feeds on it. Native to the Atlantic Ocean, a single sea lamprey can impact 40 or more pounds of fish in its life as a parasite. The Service’s Lake Champlain Fish and Wildlife Resources Office continued to evaluate and manage sea lamprey in Lake Champlain through state partnerships with the New York State Department of Environmental Conservation and the Vermont Fish and Wildlife Department. A number of techniques are used before determining an appropriate control strategy in a particular area. After permits are granted, control strategies are planned in detail among all three partners. The evidence of success is visible during pesticide treatments, but ultimately realized through decreased wounding rates and a healthier fishery.

Learn more about invasive species