Environmentalists claim Lampricide doing more harm then good
Tom Mitchell, Rutland Herald staff writer | November 12,2008
Editor's Note: The following story includes a clarification regarding the number of charter boats on Lake Champlain.
SWANTON - A program using chemicals to kill sea lamprey in Lake Champlain tributaries hasn’t reduced the lampreys' wounding of trout and salmon, appears to harm other species, while also falling short of the financial gains originally planned, some environmentalists assert.
“Our big concern is that they are expanding treatment (this year) to new streams,” said Mike Winslow, staff scientist for the Lake Champlain Committee a nonprofit group based in Burlington. Last year officials did a substantial treatment in the Poultney River, and have treated the Ausable River delta for two years, Winslow noted.
Another treatment in early October of the Winooski River killed 16 mudpuppies and killed or put at risk other nontargets species, Winslow said.
In the face of the many lamprey that have reproduced after surviving treatments, Winslow sent a letter U.S. Fish and Wildlife earlier this year asking for re-evaluation of the program.
The eel-like parasites, which grow to nearly two feet in length, attach to the sides of fish and suck out their fluids. When anglers hook a trout or salmon, they are frequently pulled from lake with the lamprey hanging off them, something anglers don’t like to see.
Although the program has led to an extensive kill of the sea lamprey, federal officials agree it has fallen short as far as reducing woundings to trout and salmon.
“It certainly hasn’t reached the targets that we have proposed,” said David Tilton, a Fish and Wildlife biologist.
The program has undergone a number of revisions since it's inception, Tilton said. A high percentage of young lamprey living in the Poultney River were killed in a treatment of that stream last year, he said. After Mill Brook in Port Henry, N.Y., the Winooski River was treated in October. A second Vermont treatment was slated for early November in the Mississquoi River and finally went forward Nov. 10, apparently marking the first time that two Vermont streams have been set for treatment in one year, officials said.
In addition, based on the finding of a steady increase in the number of young lamprey in the Lamoille River, treatments are now authorized in that stream, possibly in 2009.
However, Winslow said the state and federal fishery biolgists’ move to add new streams for treatment was not justified before the impacts of a 2007 treatment in the Poultney River had been assessed adequately over a period of at least two years.
“The (Lake Champlain Fish and Wildlife Management) cooperative has offered insufficient reason to believe that the environmental and economic benefits described for the sea lamprey program would actually be achieved by the expansion,” Winslow said.
Effects are seen over a two to three year period after a treatment is done, according Tom Berry, Lake Champlain program director for the Nature Conservancy, which has generally supported treatments.
“You are killing three years worth of lamprey" during a treatment said Berry. “You are seeing some effects in the first (year), some in the second and some in the third.”
The Nature Conservancy continues to support the program, Berry said. “They are killing a lot of lamprey,” he added.
Mollie Matteson of the Center for Biological Diversity, a nonprofit group with an office in Richmond, is worried that recent treatment of the Mississiquoi could hurt species that live there, including the mussels.
“We are going to have impacts on species in a federal wildlife reserve,” Matteson said.
Herptologist James Andrews, who has sought legal protection for the mudpuppy, the imperiled species killed in the Winooski, also has been concerned about the treatments and potential effects on all the non-target species.
“I am always nervous when they move into an ecosystem they have not treated, saturating an entire river with pesticides… that makes a lot of us nervous,” Andrews said.
There are a wide variety of nontarget species that can be hurt by pesticides, he said.
“One of the groups that really gets hit is the other kind of lamprey,” Andrews said, adding that the northern brook, silver and American lamprey are three native species vulnerable to the effects of the chemical.
WOUNDING RATES STAY HIGH
Winslow and Matteson have begun strenuously objecting to the program’s inability, in any significant way, to reduce fish woundings to the stocked native lake trout, Atlantic salmon or Walleye pike.
In terms of lamprey wounding rates seen in the last few years, studies have show that the limits of wounding fell short of the goal of 15 wounds per 100 fish for Atlantic salmon. Instead, the woundings rose to 71 wounds per 100 salmon in 2006 and stayed the same in 2007.
The number of wounds per 100 lake trout has also remained well above the target of 25 per 100 fish in 2006. In 2007, the numbers of wounds (per 100) did drop a marked 52 wounds to 46, however that occurred with a smaller number of trout sampled, Winslow noted.
The Nature Conservancy's Berry cited that reduction as a positive move in wounding rates, although he acknowledged that the wounding to lake trout is still well off the mark of 25 wounds per 100 trout. The program should be working to meet its goal of bringing wounding rates to that goal, Berry said.
Believing that chemical treatments of sea lamprey has been good for the survival of salmonids in the lake, members of groups like Trout Unlimited and the operators of charter boats have expressed support for the program.
Not only are the stocked trout and salmon caught as trophy fish in deeper water in the lake in summer, but anglers also fish for them from shore when the lake gets colder in the spring and fall, Berry noted.
“When water temps are less than 55 (degrees) Farenheit these fish can be caught in just a few feet of water,” Berry said.
“River mouths and causeways are particularly good” for anglers wanting to reel in the salmonid cold water fish, said Berry who himself fishes for salmon in a canoe in the Winooski or otherwise close to shore.
FISHING IN DEEP WATER BY BOAT
In summer, when the same salmon and trout species seek out the colder depths, “one needs a big boat, down-rigging gear and fish finder to have much success,” in catching them, Berry noted.
According to a report early this week in the Boston Globe, Bill Kirkpatrick recently described catching very thin trout with numerous wounds when he was interviewed at Datillo’s Sunoco in South Burlington, a gathering place for sportsmen.
“We used to catch 100 trout in a morning,” chimed in Reg Hawthorne at the same sports haunt, according to the Globe report. “Now we’re lucky to find 15 to 20, and they’re all scrawny.”
In Essex, Richard Greenough, owner of the 28-foot cruiser Sure Strike II, one of a number of charter boats plying Lake Champlain, told the Globe’s reporter that Vermont hasn’t been aggressive enough in stopping the lamprey.
“We could have a world class fishery but the state doesn’t want it,” Greenough said to the Globe reporter, noting his business did not do well last summer.
For the first time this year, the Mississquoi River was treated because the number of lamprey had gotten higher there.
From the view of biologists overseeing that project, the treatment had achieved a pretty good kill of the lamprey populations in a 2004 treatment of the Winooski, according to Brian Chipman, a biologist and project supervisor. However, up to 175,000 young lamprey were found in the Winooski in a survey last year and targeted in a treatment in early October, Chipman said.
The extent of actual kill from that treatment will not be determined until future testing is done in the next year or so, he said. Other fish that lamprey attach to include lake sturgeon, channel catfish and lake whitefish, Chipman has said.
FISHERY VERSUS ECOLOGY
As state and federal fishery biologists have remained committed to zapping the lamprey, the interests of fishermen and others who want to see big, healthy fish have become pitted against those interested in seeing an end to using chemicals in the rivers and its impact on the stream ecology.
And they worry about the levels of chemicals being used. For example, the levels of chemicals permitted for use last year in the Poultney River were as much as 20 percent higher than the level of one-time minimum lethal concentration that the Nature Conservancy requested in their comments on the plan last year.
“It (concentrations of TFM used) is high for some of the protected species," said Joanne Calvi, a member the South Lake Champlain group who is serving on a special committee to consider alternatives to the use of chemicals.
Where they can, fishery biologists use trapping and barrers to stop the lamprey. Still, in terms of long range objectives, “the whole program doesn’t seem to be working,” Calvi said.
To date, no species that are legally listed as threatened or endangered were found dead in preliminary assessments after last month’s treatment of the Winooski River, said Chet Mackenzie, a biologist with Vermont Fish and Wildlife. Besides the 16 mudpuppies that were killed, other nontarget species, including 13 minnows and a frog, were found and need to be identified, Mackenzie said.
Still, continued lamprey attacks on lake trout and salmon give fishery biologists a basis for maintaining pesticide applications as they find more lamprey in more streams.
“We see sea lamprey wounds on just about every fish when (we’re) talking about lake trout,’’ Eric Palmer, director of fisheries in the Vermont Department of Fish and Wildlife, said recently.
Palmer said it’s not clear to him that any of the lake trout in Lake Champlain are adept at surviving wounds by lamprey, although it does appear that fish that tend to have been there longer may have learned to survive the lamprey.
State officials say they don’t not know why lamprey numbers have remained high, but one theory is that as the tributaries got cleaner, the lamprey have fared better.
ECONOMIC MODEL, GOALS NOT MET
Citing another critical issue for the Lake Champlain Committee, staff scientist Winslow said the failure of the sea lamprey program to achieve its goals raises serious questions about the program’s economic model. It needs to be reevaluated and revised, he said.
Referring to the 2001 Environmental Impact statement for the project, the document cites a favorable return of about $29.4 million, offset by $8.4 million in costs, he said. The EIS statement said that continuing the program would also result in the same benefit or increase the return.
The source of the economic returns from sea lamprey control, Winslow said, were to come from fishing license sales, charter trips for healthy salmon and lake trout, bait sales, gas sales from boats and related items.
However, now that the program has not produced a healthier salmonid population (and economic benefits have not been seen as proposed), that outcome calls into question the model predicting a substantial financial return, Winslow said.
“Not only have those benefits not materialized, but much of the fishing pressure in the lake appears to have shifted away from lake trout and salmon and toward largemouth and small mouth bass,” Winslow said.
The warmer water bass, meanwhile, are less susceptible to lamprey wounding and do not benefit as much from the control program, Winslow said.
The needed re-evaluation of the economic impact of the treatment program should focus on fishing activities and make a distinction between the impacts from all the various target species, he said.
In terms of its ecology, the Mississqoui River in northern Vermont is similar to Rutland County’s Poultney River in that they are both big enough to support most of the species found in the lake, according to Mark Ferguson, a biologist with the NonGame and Natural Heritage Program. Ferguson quickly named the six threatened or endangered mussels in the streams that show signs of stress during treatments. The Eastern sand darter is another small fish at risk from treatments.
When biologists do surveys of streams after a treatment, they tend to scour only limited sections of a stream, and likely won’t see effects in deeper water or other less accessible areas or finds species that may have been eaten, Andrews noted. And studies on the long terms effects a chemical may have on any of the species is lacking, he said.
The Mississquoi River has been on the list for possible treatments since the early 1990s, but numbers of sea lamprey surviving there have not been high enough to warrent treatments, officials said.
In terms of reducing sea lamprey, the program has done well in the sense that it achieved a pretty good kill of the populations in a previous treatment of the Winooski in 2004, for example, according to Brian Chipman, a biologist and a supervisor for the treatment program. But up to 175,000 young lamprey were found in the Winooski in a survey last year and targeted in a treatment in early October, Chipman said. The extent of that kill will not be determined until future testing is done in the next year or so.
The manpower cost of doing a treatment is about $110,000 to $130,000 per river, with another $45,000 for the cost of the chemical -- roughly the amount spent for treatment of the Poultney River, Chipman said.
The inability of the project to achieve long term reductions in sea lamprey numbers is not its only shortcoming, environmentalists note.
Neither the trout nor salmon are reproducing successfully in the lake to the point that they’ve survived as adults as intended, Berry said. As far as salmon are concerned, the problem has stemmed from a lack of space for spawning in tributaries where dams close to the lake limit space for them, he said.
In Vermont, state fish and wildlife officials have suggested that removal of the Swanton dam on the Mississquoi could improve the grounds and help the salmon, a step the Nature Conservancy supports, Berry noted.
Still, another practical issue from a health standpoint are the detailed guidelines for the number of fish that should be eaten in given time period because of contaminants in the fish, such as mercury and/or PCB’s.
And while noting that the mudpuppy is not a listed species in Vermont in a legal sense, Matteson said it is an “imperiled” species that could be threatened in some areas within the streams in its range. And the use of chemicals is worrisome, he said. In a letter to the Lake Champlain Fish and Wildlife Management Cooperative, Matteson cited correspondence sent earlier this year by Andrews, the Middlebury herpetologist, to the Reptile and Amphibian Scientific Advisory Group, that referred to large die-offs of nontarget species after past lampricide treatments.
A treatment in the Ausable River in 1999 killed 185 mudpuppies, 4,435 tadpoles and 234 northern two line salamander larvae. Meanwhile there are indications the lamprey may be building up resistance to the lampricide, Matteson said.
TWELVE OR MORE STREAMS TO BE TREATED
At least half of the 24 streams that feed the lake have been or will be treated, according to environmental assessment completed this year.
From the standpoint of working from a good scientific basis, fisheries officials have declined to revise the Scientific Environmental Impact Statement (SEIS) for the lamprey to reflect that the lamprey is actually a native species.
In the fall of 2005, researchers from Michigan State University announced that they had determined that the Lake Champlain sea lamprey was native to the lake for thousands of years before Samuel de Champlain explored it in 1609. Officials in the lamprey control program have generally acknowledged that research indicates that lamprey are a native species rather than an exotic invasive.
From that vantage point, Berry says he objects to some officials' continued reference to the species as invasive, preferring that it be labeled a nuisance critter.
To the extent that the number of lamprey has stayed high in Lake Champlain, that seems to represent a predator imbalance in its ecosystem, Berry said.
“It (sea lamprey) is certainly out of balance now with the ecosystem,” he said.
Contact Tom Mitchell at firstname.lastname@example.org