Month: November 2010

State may have found Mussel evidence in Flathead Lake

by Dennis Bragg – KPAX (Missoula)

They’re still running tests, but biologists are worried they may have found evidence of exotic mussels making an appearance in the waters of Flathead Lake.

Montana Fish, Wildlife and Parks says microscopic larvae have shown up in four of 17 plankton samples that were taken from a sample collected in July near Woods Bay on the north end of the lake.

Eileen Ryce, FWP’s aquatic invasive species coordinator, says samples were sent to three out-of-state laboratories for testing last week.

Test results from independent labs in the Midwest suggest that tiny organisms within the sample have characteristics consistent with zebra and quagga mussels. Results from a lab in Oregon, however, suggest the sample shows no sign of mussel contamination.

“These larvae are notoriously difficult to identify at this stage of development,” Ryce explained. “With this sample the question mark is the size of the larvae, which are significantly smaller than what we’d expect. But we’ll err on the side of caution.”

Ryce said FWP will send a team of divers to several locations on the north end of Flathead Lake to search for adult mussels, which could be as tiny as sesame seeds.

The sample that contained the suspicious, microscopic larvae was among 11 collected from Flathead Lake by volunteers from the Whitefish Lake Institute in July and delivered to FWP in late September. The remaining suspected samples will be submitted for additional DNA testing.

FWP has also alerted downstream agencies in Idaho, Washington and Oregon since the organisms could be carried into the extensive Columbia River system via the Flathead River.

Zebra mussels were first discovered in the Great Lakes in the 1980s and appeared in Lake Mead in 2007, causing all Western States to begin screening for their spread. In Montana testing has focused on Flathead, Fort Peck Lake and Canyon Ferry because those waterways see the highest amount of non-resident boating traffic.

Lake Champlain has Healthy Whitefish Population

JEFF MEYERS
Press-Republican

PLATTSBURGH — An ongoing study looking into whitefish in Lake Champlain has found a thriving population hidden deep in its murky depths.

The whitefish is a popular sport and commercial fish in the Great Lakes, where it has faced some major problems of late, but it has become a widely ignored bottom feeder in Lake Champlain.

“The whitefish population in Lake Champlain is doing fine,” said Dr. Ellen Marsden, a University of Vermont professor and scientist who is spearheading the whitefish study.

“Everything seems to be going well for them: Their fertility looks good, they’re eating well, they have good growth and low mortality.”

CHANGE IN DIET

Whitefish are a long-lived species, surviving a quarter century or more. The Lake Champlain research project has shown strong consistency in age groups with no discernible gaps that might suggest a die-off problem during any given year over the past few decades.

Marsden turned her attention to Lake Champlain whitefish as a natural progression from research she has assisted with in the Great Lakes.

“In recent years, there have been some dramatic changes in whitefish populations (throughout the Great Lakes), primarily because of a change in their food source,” she said.

A major portion of the whitefish’s diet in the Great Lakes has historically focused on a shrimp-like burrowing creature called diporeia that has also seen a dramatic decline in numbers over the last decade.

Although a cause for the drop in diporeia is not certain, scientists believe the Great Lake’s increase in zebra mussels has had a dramatic impact on the crustaceans.

“Subsequently, the whitefish got into trouble because they didn’t have their favorite food, and they started to eat zebra mussels, which are not a good source of food,” Marsden noted.

“In Lake Champlain, we don’t have abundant numbers of diporeia, so the whitefish’s old food source has not been damaged. That’s how my interest in this lake’s whitefish population got tweaked.”

The only study on whitefish in Lake Champlain took place 80 years ago when the species was important commercially. Though it has been largely forgotten, Marsden felt compelled to see if zebra mussels were playing a role in the health of Lake Champlain whitefish as well.

“Basically, what we found is that they are not eating zebra mussels,” she said. “Even though the (lake) bottom is lined with zebra mussels, they are for the most part ignoring them.”

PRIZED ELSEWHERE

The whitefish diet here varies. They eat mostly fish eggs — including their own species — during the spring and switch to a crustacean commonly called the opossum shrimp in the summer. They feed mostly on snails during the rest of the year but continue to avoid zebra mussels.

“From a biological standpoint, this raises an interesting question,” Marsden said. “What is the motivation for eating something — in despair because a favorite food is gone or eating it simply because it’s there—”

As commercial fishing on Lake Champlain declined in the early 1900s, the interest in whitefish both commercially and as a sports fish also disappeared.

“Today, anglers don’t even seem to know what they are,” Marsden said. “It’s not a fish that you would accidentally catch if you’re looking for something else.”

In other areas, the whitefish is still a prized sports fish, she added. In Maine, for instance, whitefish tournaments are held throughout the season. They also remain a popular seafood choice in the Midwest and even in New York City, she added.

Marsden believes the Lake Champlain whitefish population could easily handle an active interest from sports anglers and suggests that actively seeking them out could pose a new challenge for anglers.

The adult whitefish grows between 17 and 22 inches in length and can weigh from 2 to 4 pounds. The record catch weighing in at 41 pounds was taken from Lake Superior in 1918.

E-mail Jeff Meyers at: jmeyers@pressrepublican.com

Zebra Mussel Could Invade Candlewood Lake

By: Nancy Eve Cohen

The zebra mussel, an invasive species, was discovered in Lakes Zoar and Lillinonah about a month ago. But some people are concerned it could also end up in Candlewood Lake. The Candlewood Lake Authority is holding a panel discussion tonight on the zebra mussel at Western Connecticut State University. WNPR’s Nancy Cohen reports.

The zebra mussel is considered a kind of poster child for invasive species because it can be so destructive. The mussel, which comes from Russia, reproduces rapidly, choking out native mussel species and changing the way ecosystems function. They adhere, en masse, to any hard surface and can clog industrial pipes. The razor sharp shells can be dangerous for swimmers.

The zebra mussel was first found In Connecticut in East and West Twin Lakes in Salisbury in 1998. Just last year it was discovered in Laurel Lake in Lee, Massachusetts, not far from Connecticut. And in a stream from that lake that feeds the Housatonic River and in the river itself. Now it’s also in Lakes Zoar and Lillinonah. Ethan Nedeau is an ecological consultant for First Light, which has hydro electric facilities on the river. Nadeau says part of Candlewood Lake contains calcium at levels that the mussel needs to thrive.

“It does seem pretty likely that overtime zebra mussels will reach Candlewood Lake and conditions are certainly favorable in the northeast arm of the lake.”

Peter Aarrestad of the Connecticut Department of Environmental Protection says the state is working hard to educate fishermen and others to clean all the water out of their boats before going from one lake to another to prevent the spread of the mussel

“Even removing aquatic plants from a boat trailer because the very small mussels can adhere to plants. That’s actually a fairly common way the mussels are transported from one water body to another.”

About 800 live zebra mussels were found in Lake Zoar and about 30 in Lake Lillinonah. It’s not known yet how they got there.

For WNPR, I’m Nancy Cohen.

Tide building on cleaner water

The sense of alarm in Prior Lake over dirty water is likely to spread as more “impaired waters” get clean-up orders.

By DAVID PETERSON, Star Tribune

Watching the filming of a documentary on the Minnesota River that aims to draw attention to its mucky waters, Tim Lies was struck by something.

“They were filming the Belle Plaine river-fishing contest,” said the mayor of that city. “And these were not tree huggers; they were catfish-fishin’, tobacco-spittin’ guys. And yet everyone in the group was extremely conscious of the environmental factors affecting the river. And it struck me, ‘Gosh, this is a metamorphosis that is the result of 20 years of work to raise awareness.'”

Environmental activists and government officials agree that they’ve never seen as much interest, as much knowledge, as much money pouring into the issue of water quality in the south metro area.

And yet they are also bracing for struggles, because a wave of new studies showing just how polluted most bodies of water around us really are is going to lead to a wave of “implementation,” pushing farmers, lakeshore owners and others responsible for the damage to change their ways.

The televised forum for candidates for Prior Lake City Council last month found fierce disagreement on some issues, but none on the need to make water-quality improvements a top priority.

That was probably the result of two well-publicized hits on the city this year: The news that its crown jewel was infested with zebra mussels, followed not long afterwards by the release of a Minnesota Pollution Control Agency (MPCA) report on the serious impairments in the connected waters in Spring and Upper Prior Lakes.

Beyond that, state officials say, similar studies are coming up on other lower-priority, smaller bodies of water.

And there’s an irony in Prior Lake becoming a poster child for water quality, they add: The city has been a pioneer in addressing the problem.

“I’m impressed with the work they’re doing,” said Chris Zadak of the MPCA. “They have been a real standout, for instance, in the area of salt and chloride.”

In 2008, the city started attacking chloride levels in Blind Lake with a “liquid brine only” program that reduces street salt use to one-seventh the quantity that was common a decade ago. Since then, according to a city memo released a few days ago, chloride in the lake is markedly down — leading to an expansion of the same program to other areas.

The process that has led to heightened concern in Prior Lake — a listing as “impaired” under the federal Clean Water Act, followed by a detailed study of what’s causing the problem, then a plan of attack — takes many years. It’s underway on many bodies of water other than in Prior Lake.

Scott County commissioners have expressed impatience that so much money seems to go into consultants and studies versus action aimed at solving things. But environmentalists say it’s vital to figure out what the major causes and solutions are rather than rush in and waste money on moves that don’t end up changing anything.

“I’ve seen some that are really well done,” said Kris Sigford, water quality specialist for the Minnesota Center for Environmental Advocacy, “so you can target the dollars in ways that make a difference — and some poorly done, vague ones that don’t provide a road map at all.”

One small sign of the change required:

The Prior Lake-Spring Lake watershed district reports that on some farms south of Prior Lake whose erosion ends up in those lakes, soil loss is running 12 times as high as the county allows: 60 tons per acre per year, when the permissible loss is five.

Reducing that, officials add, not only will make streams and lakes less muddy, it will also cut down on the pollutants such as phosphorus and nitrogen clinging to all that dirt and holding the potential to make the water on the beaches of posh lake homes so toxic that dogs can die from lapping at the shore.

The consequences for people are key to public support for solutions, said County Commissioner Tom Wolf.

“Prior Lake, Spring Lake — people are on those lakes,” he said. “Their homes are on those lakes. They didn’t move to the lake to have it be green.”