Invasive Species ready to take over Lake Champlain

Keeping Lake Champlain’s habitat free of non-native species is no easy task

Story and photos by Kyler Klix

When the sun is shining and people are enjoying Lake Champlain, they see the natural beauty of the lake. What they do not see is the habitat located within the lake swarming with all various forms of life. What they also miss out on is the forms of life being threatened by the amounts of invasive species fighting for a prolonged existence.

“Research shows big disruptions when invasive species enter,” Timothy Mihuc explained. “When they come in, they really have an impact on the system we’re trying to conserve.”

“You could tell in the behavior in the fish that they were acting pretty lethargic. The signs and symptoms pointed to a lack of thiamine.”

Mihuc is the director of the Lake Champlain Research Institute. He primarily researches different invasive species.

Millions of fish are placed into all sorts of waterways throughout the North Country region. Thousands of fish in Lake Champlain came from fish hatcheries located in New York and Vermont. This happens because the fish populations are lower than what they should be at.

“The stocking supplements natural populations,” Mihuc said. “The DEC stock and restore so they (fish) can naturally reproduce, but they always stock more each year.”

There are stocking facilities in the North Country and many more located throughout New York and Vermont. Each raise different species of fish and send them to different areas throughout the area. The DEC-operated fish hatcheries send fish all across the state. In Lake Champlain, 45,000 brown trout were placed in the water in 2008.

In Vermont, the Ed Weed Fish Culture Station produces 130,000 pounds of fish in an 18-month cycle and over 350,000 land-locked salmon and brook trout fry, which are young fish.

While the station does this to get balance the natural populations, they found a problem in January 2009 with the eggs they use to produce the fish.

When the fish started hatching, they showed increased exhaustion, mouth gaping and encephalitis, which is an inflammation of the brain — all signs of Early Mortality Syndrome, or EMS.

“You could tell in the behavior in the fish that they were acting pretty lethargic,” said Kevin Kelsey, the hatchery manager. “The signs and symptoms pointed to a lack of thiamine.”

Thiamine is vitamin B1. It is essential in the diets of adult salmon because it provides the nutrients to make the eggs healthy. The EMS showed that there was a lack of thiamine in the salmon’s diet, and those at the Ed Weed Culture Station needed to solve the problem before it got out of hand.

The station contacted researchers from other institutes who have seen similar problems in the Great Lakes. Kelsey and others working at the station received a solution based on Atlantic salmon in the Great Lakes, which they followed through with and documented the results.

“The hatchery had to bathe the eggs in thiamine, and the eggs absorbed it,” Meg Molden said, aquatic nuisance species coordinator from the Lake Champlain Basin Program.

All of the eggs went through the procedure, and the mortality rate in the salmon fry dropped by almost 10 times what it equaled before.

“It’s like magic when it happens,” Kelsey said.

He added that the thiamine problem didn’t hurt the production this year, but it is something they will be concerned with in the future. There will be dorsal fin-injections given to many of the adult salmon, which should provide a sufficient amount of thiamine.

“If we ever took a huge hit, we have a backup,” he said.

This problem came from an intruder in the ecosystem. The primary cause for a lack of thiamine in the diets of salmon was because of the invasion of alewife, a foreign fish to Lake Champlain. The fish was introduced to the water in 2003, and it has begun altering with the existing natural habits.

Mihuc explained that once a species is introduced, it could take three to five years for it to grow in numbers, and by the seventh year most would reach their peak population level. From there, the species will reach a stable population.

This fish is just one of the 49 species of non-native plants and animals located in Lake Champlain. The number is half compared to surrounding bodies of water, but it is a number that rarely decreases, and often increases. There are over 180 invasive species documented in the Great Lakes. The St. Lawrence River has 87, and the Hudson River has 91. And Lake Champlain is right around the block.

James Elhers is the executive director of Lake Champlain International Inc. He said the number of invasive species can climb on a steady pace. The most recent intruder to the lake is a plant called water milfoil, discovered around Sept. 20, 2009.

“From the 20s through the 80s, roughly three new species a decade were ‘discovered’ (in Lake Champlain),” he said. “During the 90s, there were 12 and since 2000, we are working on seven.”

"A huge amount gets moved accidently because people are not aware of the effects. They don’t know that it will actually hurt the environment.”

While more awareness has prevented some from entering, the number has stayed lower compared to the other waters because of Lake Champlain’s geography.

“Lake Champlain is relatively isolated from other bodies of water, and that is why there are fewer invasive species,” Mihuc said.

Lake Champlain was naturally isolated from these other bodies of water, but manmade canals built throughout the 1820’s have connected the waterways, making it possible for invasive species to travel from one body of water to another. Water chestnut entered Southern Lake Champlain from the Hudson River through the canal. Elhers said about a quarter of the invasive species originate from to the canal system.

In the case of the alewife, it is most likely that a human moved the fish. It could have possibly been an angler looking to increase the number of baitfish in Lake Champlain to help the other fish grow in size, Mihuc said.

“A huge amount gets moved accidently because people are not aware of the effects,” he said. “They don’t know that it will actually hurt the environment.”

People are the primary transporters of a species from one place to another, he said. Boats often carry species from one body of water to the next place they visit, whether discharging their water passing into another one, or moving a boat from one lake to another.

Another way many plants and other fish transfer to the lake is through gardening and aquarium trade. People buy certain plants or species of fish through different possible ways. When they grow out too large or people want to get rid of them, people place the plants or aquarium species outside. From there, the plants and animals can spread in a number of ways and possibly survive.

The water milfoil could possibly be traced to aquarium trade, but it could have traveled via boat because it has been found in surrounding waters.

It is difficult, and almost impossible, to rid the invasive species once their presence is strong. Mihuc said it is much more important to take a preventative measure rather than a reactive measure. One that the government spends millions of dollars to control is a plant called water chestnut, but it still exists in the lake.

“Some you can attempt to get rid of, but it is like weeds in a garden or termites in a house,” Mihuc explained. “You never really can get rid of them for good. The best strategy is to not let them in.”

There are many different strategies in preventing the spread of invasive species, and many deal with education and informing the public.

“There are numerous, some very elaborate mechanically and chemically, but we, our organization, relies on education,” Elhers said.

Most research agencies that work with the lake spread awareness with signs, brochures and notices, but there is natural ways for invasive species to get into the lake.
One that Mihuc is spreading awareness about is on Lake Champlain’s doorstep is the spiny waterflea. The species made its way from the Great Lakes into the Great Sacandaga Lake, making it very possible for the waterfleas to travel to Lake Champlain through the Hudson River and Champlain Canal.

Molden explained that the Lake does not belong to one state, or even country. Since Lake Champlain borders New York, Vermont and Quebec, there are funds and agencies going in all different directions. One of the most effective strategies is to work together, Molden said.

Elhers works interstate and internationally and said it is challenging between the laws and procedures working with other organizations, but it should not be as difficult when dealing with something as harmful as invasive species.

“When dealing with a public matter like invasives, there is no limit to the number of people that should be reached with the educational message or partner organizations to be contacted to assist,” he said.

There are more invasive species to come to Lake Champlain in a hard battle to defend. Mihuc warns that there are “well over 100 Great Lakes invasive species poised to enter Lake Champlain.” Will there be any way to stop it? Will they all be ready to take over the lake? It could be a long battle with plenty of change to develop.

What do you think about invasive species?