Spiny Water Fleas Have Arrived – What Next?

Spiny Water Flea, Bythotrephes longimanus (Credit: Kate Feil via USGS.gov)

Spiny Water Flea, Bythotrephes longimanus (Credit: Kate Feil via USGS.gov)

On August 25 four individual spiny water fleas were found during routine monitoring of Lake Champlain. The invasive exotic zooplankton species were discovered in the middle portion of the Main Lake between Burlington and Port Kent. Since then they have been confirmed from a total of three monitoring stations. They had previously colonized Lake George and their arrival in Lake Champlain, though disappointing, is not unexpected. Read on to learn more about their potential impacts, the Champlain Canal’s role in the spread of invasive species, and preventative actions needed by all boaters.

Spiny water fleas were first found in North America in 1982 in Lake Ontario. Since then they have spread throughout the Great Lakes and a number of inland water bodies. They reached the Great Sacandaga Lake on the western edge of the Adirondacks by 2008 and Lake George in the Lake Champlain watershed by 2012.

Zooplankton are small animals that live in the water column and drift with the currents. While most zooplankton are microscopic, the spiny waterflea can be seen with the naked eye. Still, a dozen or more would fit on a fingernail. Zooplankton play two very important roles in the ecosystem. First, they provide food for fish, especially rainbow smelt and alewives, the principal prey of lake trout and salmon. Second, they eat algae, potentially keeping some blooms in check.

Dr. Jason Stockwell of the University of Vermont has offered four predictions about how spiny waterfleas could change the ecology of Lake Champlain. Stockwell is the director of the Rubenstein Ecosystem Science Lab on Lake Champlain. Prior to that, he was station chief at the Lake Superior Biological Station in Ashland, Wisconsin. He based his predictions on his own experiences in the Great Lakes and a review of the literature, which mostly compares lakes in the Canadian Shield with spiny waterfleas to those without.

First, he felt that the spiny waterflea’s impacts would most widely be felt in the Main Lake and Mallets Bay. These areas of the lake have clear waters compared to the murkier waters of Missisquoi Bay and the South Lake. Spiny waterfleas use visual cues to find and catch prey, so they would have an easier time feeding in the clearer waters.

Second, spiny waterfleas would compete with rainbow smelt and mysids (a group of small, shrimp-like crustaceans) for food, leading to drops in those two populations. Both rainbow smelt and mysids provide important forage for lake trout and salmon, and both populations have already seen declines. Rainbow smelt were the dominant forage fish in the lake until the arrival and spread of alewives about 2003. While rainbow smelt can eat spiny waterfleas, the large spines provide little nutrition and have been found to fill up fish stomachs without being digested. Mysids, also known as opossum shrimp, play an important role in the energy and food dynamics of the lake. They migrate vertically in the water column each day providing a transfer of nutrients and energy from sediment and deeper water up into the water column.

Third, the prey of rainbow smelt, mysids, and spiny waterfleas are cladocera, another, medium-sized form of zooplankton. Stockwell predicts their population would go down as a result of the new predator. The presence of spiny waterflea affects them in two ways. Most obviously, the cladocera become food. However, the waterfleas also affect the cladocera’s behavior. In the presence of spiny waterflea the cladocera spend less time near the water surface where their food is more plentiful, but so are their predators. As a result, they grow more slowly when spiny waterfleas are present.

Cladocera are a group of medium-sized plankton. While the overall numbers for the group as a whole may go down, some of the species that have behaviors or defense mechanisms that help them avoid spiny waterfleas could actually increase in number.

Fourth, if the cladocera numbers go down, then the things that the cladocera eat may increase. Rotifers are tiny zooplankton. They are too small to attract the attention of spiny waterfleas but constitute the main food for cladocera. Rotifers may just thrive in the presence of the new invasive species.

A fifth possible outcome has been predicted in other systems but not actually measured. Models suggest that spiny waterfleas in a system could lead to a five to ten percent increase in mercury concentrations in fish. Mercury, a potent neurotoxin, accumulates with each step up the food chain, thus smaller organisms have lower concentrations than larger organisms. Spiny waterflea may add another step in a lake’s food chain, thus increasing opportunities for accumulating mercury.

In addition to the potential ecosystem effects that spiny waterflea may cause, they are also a nuisance for anglers. Two-thirds of the length of the animals’ bodies is a long spine that can become caught on fishing line. At very high densities the spiny waterfleas accumulate on the line and make it difficult to reel in.

The potential impacts of spiny waterflea and other invasives like them have led the Lake Champlain Committee and others to call for physical barriers in the Champlain Canal that would limit opportunities for species to spread. Of those exotic species whose origin of introduction to Lake Champlain is known, over 60% entered via canals with the majority of those coming through the Champlain Canal. There are still more waiting to get in. Round goby, a fish species, and Quagga mussels, a close relative of zebra mussels that live in deeper water, are in the Erie Canal system and making their way eastward. The highly invasive plant hydrilla can reach the canal from where it has been found in Seneca Lake. It is not clear how spiny water flea got to Lake Champlain, but it is clear that the Champlain Canal creates the greatest risk of other species getting here. How many more invasive species will Lake Champlain have to endure before the vital link of the Champlain Canal is finally addressed?

Now that spiny water fleas are in Lake Champlain it is ever more imperative for lake users to take steps that will slow their spread to other water bodies. The simple mantra for all gear that touches the lake is CLEAN, DRAIN, DRY. Clean – make sure there are no visible plant or animal parts on your boats or gear. Drain – remove all water from inside boats, coolers or anything else that might have lake water. Dry – don’t reenter water until gear has dried enough to kill anything that might still be living there. This last item is particularly difficult with spiny water flea, since their resting egg stage is resistant to drying. Additional disinfection with bleach or hot water may need to become part of the routine to prevent spiny water flea movement.

Feral Pigs in the Adirondacks

Feral swine adults and piglets

Feral swine adults and piglets (Credit: NYDEC)

It’s time to reexamine our previous post, “Feral Pigs in Champlain Valley,” with an update on the situation in the Adirondacks.

Feral pigs (feral swine/wild boars/razorbacks/wild hogs–whatever you call them) have made their presence known locally in New York State.

Feral pigs have established a breeding population on the eastern edge of the Adirondack Park. Scientists fear the animals could spread fast, wiping out native animals and damaging crops. [...] Pigs breed fast, with populations sometimes tripling in a single year. If that happens here, [wildlife technician with the Department of Environmental Conservation Ben] Tabor says, the environmental impact on Adirondack forests could be dramatic. (NCPR)

These animals are not a natural species in the Champlain Valley, and hence can upset local ecosystems, including becoming problems for farmers. Last summer there were reports of a group of feral pigs troubling a farm in Peru, NY.

Why are these animals a problem? This invasive species can destroy natural landscape and agricultural lands, upset local ecosystems, and also can carry diseases that are transmissible to other animals and humans.

Learn more about the Eurasian Boar on the DEC website.

Dealing with Feral Swine

Wild boar

Wild boar (Photo credit: mape_s)

The New York State Senate and Assembly recently passed legislation at the prompting of the New York State Department of Environmental Conservation (DEC) that will prohibit the “importation and possession of the Eurasian boar, otherwise known as feral swine” effective September 2015.

However, there is still the population of feral swine already out in the Adirondack wilderness that must be dealt with.

Attempts to trap the nocturnal animals are tricky to accomplish because these pigs are resourceful and seem wise enough to avoid a trap that they’ve previously encountered.

To give the situation some numbers, here is a statement from the 2013 New York State Legislative Summer Newsletter about the recent removal of feral swine:

“The removal of 25 boars in Clinton County cost the DEC and a division of the USDA $68,000, or more than $2,600 per animal.”

What can you do?

Eurasian wild boars

Eurasian wild boars (Photo credit: Marie Hale)

In New York, people with a small game hunting license may shoot and keep Eurasian boars at any time and in any number. All other hunting laws and firearms regulations are still in effect when shooting Eurasian boars. [...]

If you do shoot or see Eurasian boars, or any feral swine, please report them to the nearest DEC regional wildlife office or e-mail us. Please report the number of animals seen or killed, whether any of them were piglets, the date, and the exact location (county, town, distance and direction from an intersection, nearest landmark, etc.). Photographs of Eurasian boars are greatly appreciated, so please try and get a picture and include it with your report. (NYDEC)

What do you think about this situation? Do you believe it is a serious problem? Any thoughts on how it should be dealt with?

Have you encountered any wild hogs or evidence of their presence in the Champlain Valley or near Essex, NY? If so where? Share your insights in the comments below!

Monitor Lake Champlain: Blue-Green Algae & Invasives

Blue-Green Algae

Blue-Green Algae (Photo credit: Lake Improvement Association)

The Lake Champlain Committee is dedicated to protecting Lake Champlain. They recently created a pledge to protect the Lake Champlain so you can learn how to protect the lake too! But you can do more than just take the pledge and practice environmentally safe actions; you can volunteer to help patrol the lake for the committee! Right now they are looking for more volunteers to help monitor the lake for blue-green algae and other problematic species this summer.

Blue-Green Algae

Blue-green algae can be damaging to human and animal health, so it must be monitored to ensure that contact is avoided. Each summer LCC trains and oversees volunteer monitors who will report on algae conditions in their area, so as to study the algae and determine areas that are safe for swimming.

We’re gearing up for the summer monitoring season and are looking for people who can regularly report on water conditions. Blue-green algae monitors receive training to assess water conditions, visit the same site throughout the season and file a weekly online report from mid-June through Labor Day. The program provides critical data on where and when blooms are happening and is relied on by public health and environmental agencies to assess whether the water is safe for recreation. It also adds to our knowledge about the triggers for blooms so we can reduce their frequency. Let us know if you have a lakeshore location you’d like to monitor. (Lake Champlain Committee)

Visit the Lake Champlain Committee website for more information and to find the full list of sites that need to be monitored.

Aquatic Invasive Species

Zebra mussel GLERL 2

Zebra mussels are an invasive specis in Lake Champlain (Photo credit: Wikipedia)

Another summer protection project you could be involved in is patrolling the lake for aquatic invasive species. These non-native invaders can damage the already existing ecosystem of the lake because they may not have any natural controls (predators, water/weather conditions, competing species) and their populations could grow too large to sustain and/or push out native species.

LCC is partnering with the Vermont Agency of Natural Resources to get more people out on the water reporting about aquatic invasives. Early detection is key to controlling or eradicating new populations. Help protect the lake’s biodiversity by becoming a VIP – Vermont Invasive Patroller. Patrollers will be trained to identify and distinguish native species from invasive ones and to conduct systematic on-the-water surveys. VIPs need to participate in a half day informational workshop, have access to a boat, and submit two survey reports per year. (Lake Champlain Committee)

The Lake Champlain Committee organizes many volunteer events and activities. Please email Lake Champlain Committee at lcc@lakechamplaincommittee.org, fill out this online form, or call the LCC office at (802) 658-1414 if you’re interested in any of the Lake Champlain Committee’s volunteer opportunities.

Feral Pigs in Champlain Valley

Wild pig

Wild pigs. (Photo credit: Wikipedia)

It sounds strange, but feral pigs (wild boars/razorbacks/wild hogs–whatever you call them) seem to have made a home in New York State. Normally we hear about these animals in states further south, but somehow this summer they had made their presence known locally!

These animals are not a natural species in the Champlain Valley, and hence can upset local ecosystems, including becoming problems for farmers. This summer there were reports of a group of feral pigs in Peru, NY, that had begun causing a nuisance to a local farm.

Attempts to trap the animals are tricky to accomplish because these pigs are resourceful and seem wise enough to avoid a trap that they’ve previously encountered.

The traps are circular because feral pigs have been known to crowd into the corners of other traps and climb atop one another to escape. Last year, the state set a similar corral trap too soon, catching only three pigs. After that, none of the others returned to the area, even after the trap was dismantled. (The New York Times)

Problems Feral Pigs Can Cause

Wild Boar

Wild Boar with babies in background (Photo credit: stewartmorris)

If enough of these feral swine increase their numbers they can cause several problems for farmers, upset local ecosystems, and may cause other problems for the average human in the area. Some of the troubles they can cause include:

  • Can locally decimate the fall acorn crop, leaving virtually none for native wildlife such as bear, turkey, white-tailed deer, squirrel and waterfowl.
  • Disturb and prey on ground-nesting birds (like turkey and grouse) and their eggs which may decrease game bird populations.
  • Will kill and eat fawns and young domestic livestock.
  • Prey on reptiles and amphibians (such as snakes, lizards, frogs and salamanders) and their eggs which may impact these populations.
  • Will eat almost any agricultural crop as well as tree seeds and seedlings.
  • Tear up lawns and golf courses to eat the tender roots, grubs and worms.
  • Wallow in wet areas where they destroy native vegetation, cause erosion, and negatively affect water quality.
  • Have razor sharp tusks and can be aggressive toward humans, pets and livestock.
  • Can carry and transmit at least 30 diseases including swine brucellosis, E. coli, trichinosis, and pseudorabies to native wildlife, livestock, pets and humans. Pseudorabies, if transmitted to domestic swine, can decimate NY’s pork industry. (New York Hunting and Trapping)
a young wild boar

A young wild boar. Are they still in the Champlain Valley? (Photo credit: Wikipedia)

Perhaps the pigs in the Champlain Valley began their wild life by escaping from a farm and procreated to increase their numbers, or they may have simply migrated into the area?

Has anyone else heard or seen any of these wild pigs or evidence of their presence in the Champlain Valley? More information is needed to know if they are an increasing population here or if there have only been a few incidents.

 

Are Lampreys an Invasive Species?

Sea lamprey illustration. The original caption...

Sea lamprey illustration. The original caption read: Fig. 586.–Petromyzon marinus, sea lamprey. (After Goode.) (Photo credit: Wikipedia)

There is some debate about the origins of the sea lamprey in Lake Champlain. Some call them invasive species, but recently there have been discoveries that may point to this disliked species being more local than previously thought.

Invasive species are plants or animals that are not native to an area, and when introduced become a problem to the original ecosystem. Sea lampreys have been causing some problems in Lake Champlain, but are they invaders or simply a species that has grown out of control?

Let’s Look at the Evidence

Is the sea lamprey invasive species? It had long been believed that the lamprey had entered “Lake Champlain via the Champlain Canal, the Richelieu River and Canal, and over land primarily through human activities such as boating and bait transport” (Lake Champlain Basin Program).

“The sea lamprey was first noted in Lake Champlain in 1929 by J.R. Greeley, who reported that sea lamprey were found in moderate numbers at that time. It is not clear if, or for how long, sea lamprey had existed in Lake Champlain prior to this time.” (NYDEC)

English: Sea lamprey wounds (Petromyzon marinu...

Sea lamprey wounds (Petromyzon marinus) on a salmon (Photo credit: Wikipedia)

If we take into account that fishing was a major source of food for settlers and natives at the time, and also consider the fact that sea lampreys leave obvious signs of their presence on the local fish – wounds, scars, and attached lamprey – “the lack of mention of lamprey in the oral and written history is consistent with the position that sea lamprey may be a non-native invasive species.” (NYDEC)

New Evidence Points to Native

Despite this long-held believe, recent genetic studies indicate that the sea lamprey may actually be native to Lake Champlain (NYDEC).

Some people now believe that the sea lamprey may be a native species leftover from the Champlain Sea  (Lake Champlain Basin Program). If this is true, then why have sea lampreys only recently begun to cause problems?

It may be because of:

  1. “The change in human use of the lands and waters in the lake’s watershed may have resulted in increased habitat for larval lamprey” (NYDEC).
  2. Also the original Lake Champlain salmon and trout have died out and the foreign strains introduced to stock the lake did not evolve with lamprey, therefore these fish may be more susceptible to sea lamprey parasitism (NYDEC).

Does their origin matter?

Do the lampreys have a right to be in Lake Champlain if they are native?

Native or non-native, are sea lampreys in Lake Champlain causing a major problem? Some believe that if left unchecked other fish populations would be seriously impacted as the parasitic sea lampreys feed on and kill other species–many of which are sought after by anglers.

Sunset on Lake Champlain, taken from hotel win...

Lake Champlain (Photo credit: Wikipedia)

Organizations from New York and Vermont have collaborated to create a lamprey control program. The program is not trying to exterminate the lampreys, but is trying manage them.

Some environmentalists are concerned that the methods used to control the lampreys are damaging to the ecology of the lake. Some others consider the freedom of the lake’s various species to be greater than the need to for the lake to be an angler’s tourist destination.

What is your opinion?

Lake Champlain Lamprey Problem

Sea Lamprey (Petromyzon marinus)

Sea Lamprey (Petromyzon marinus) (Photo credit: Wikipedia)

The sea lamprey (Petromyzon marinus) is one of four lamprey species found in the Lake Champlain Basin out of 31 species found world-wide. According to some, the sea lamprey species is proving to be a problematic presence in Lake Champlain.

What is a Lamprey?

Lampreys are eel-shaped fish with a skeleton made of cartilage, with smooth, scaleless skin and two dorsal fins on their backs.

“The sea lamprey is parasitic; it feeds on other fish, using a suction disk mouth filled with small sharp, rasping teeth and a file-like tongue. These are used by the sea lamprey to attach to a fish, puncture its skin, and drain its body fluids.” (NYDEC)

Petromyzon marinus, sea lamprey. U.S. Fish and...

A close-up of a sea lamprey’s mouth (Photo credit: Wikipedia)

Sea lamprey have a cylical life cycle:

  • “The first four years of their life are spent as ammocoetes – a blind worm-like larval stage – in the soft bottom and banks of waters that flow into Lake Champlain.” (NYDEC)
  • Then they transform into the parasitic adult stage and enter the lake to feed.
  • “After twelve to twenty months in the lake the adults migrate back into the streams flowing into the lake to spawn”–tens of thousands of eggs from a single pair!  (NYDEC)
  • Soon after spawning, the adults die.

Negative Impacts of Lake Champlain Lampreys

Lake Champlain lampreys have become a serious problem to the other fish populations in the lake.

“Studies on the Great Lakes show a 40 to 60 percent mortality rate for fish attacked by sea lamprey. Other studies have found that a single sea lamprey can kill 40 or more pounds of fish during its life. Even when fish survive the attacks, the fish populations will decline as the fish expend more energy on healing than on producing eggs and mating.” (NYDEC)

An invasive sea lamprey as seen feeding on an ...

Sea lamprey as seen feeding on an unfortunate salmon. (Photo credit: Wikipedia)

This reduced number of fish has given a harsh blow to the fishing industry in the Lake Champlain region. With less and less fish for anglers to catch, fewer fishing tourists are visiting our lake. Some are even spreading the word that this is not the place to vacation if you want to fish!

This is having an overreaching effect on those “whose livelihood is directly or indirectly supported by the fishing and tourist industry” (NYDEC).

Ways to Control Lampreys

Lake Champlain lamprey control programs are run jointly by the US Fish and Wildlife Service, the VT Fish and Wildlife Department, and the NY State Department of Environmental Conservation (Lake Champlain Basin Program).

A “long-term control program began in 2002 following the evaluation of an eight-year experimental program. Thirteen tributaries were treated with the chemical lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and Bayer 73 was used on five tributary deltas.” (Lake Champlain Basin Program)

These chemicals have proven to be non-harmful in the waters they have been used in. After years of study, “fisheries managers have concluded that the lampricides have little or no known permanent effect on populations of non-target species present in the treatment areas.” (NYDEC)

Other non-chemical alternative sea lamprey controls that have been tested include:

  • Nest raking/disruption
  • Sterile male release
  • Trapping
  • Installation of physical controls and low head barrier dams

Are Lake Champlain Lamprey Controls Working?

These methods combined have shown a positive effect. The negative effects of the Lake Champlain lampreys are decreasing, and the fish population in the lake is being restored. More work must be done to ensure this continues.

“Results from the program showed that the number of sea lamprey wounds found on lake trout decreased, as shown on [this] Sea Lamprey Wounds graphic.

In addition, the average number of sea lamprey wounds on landlocked Atlantic salmon decreased, and the number of salmon and lake trout caught increased.” (Lake Champlain Basin Program)

Total eradication of the Lake Champlain lamprey population is not the goal of the program, but rather to reduce the impacts of sea lampreys on the lake’s fishery and to restore balance to the ecosystem (NYDEC).

Leek Moth Invasion

Leek Moths Invade Essex County

Leek Moths Invade Essex County

Shortly after adding two flats of baby leeks to our vegetable garden, the phone rang and my mother burst my vichyssoise bubble.

“Did you read about the leek moths?” my mother asked dramatically.

“The what?”

“Leek moths,” she repeated as if I should know what she was talking about.

“No. Just finished planting my leeks though…”

She summarized the article she’d just read in the The Valley News about an invasive moth species recently spotted in Essex County.

Anita Deming of Cornell Cooperative Extension in Westport reported to members of the Economic Development, Planning and Publicity Committee June 11 that they had found the first reported case of leek moths in Essex County… Leek moths are an invasive species which live off of plants like onions, garlic, leeks and chives. (The Valley News)

Jolly news to reward back-aching gardeners and local farmers. Just finished penciling in your last leeks? Just finished thinning and transplanting your chives? Bad luck!

Although I didn’t grow garlic or onions this year, we planted plenty of leeks and we have an approximately 3’x6′ area of our herb garden dedicated to perennial chives. I’m crossing my fingers that we’ll get lucky or discover a non-toxic means of combating the leek moths.

But Deming isn’t offering much room for optimism.

“The larvae feed off of those plants,” Deming said. “They are all plants that our local farmers like to grow and sell… You have to spray, and a lot of our farmers pride themselves as purely organic farms,” she said. (The Valley News)

Pesticide? Uh-oh. There’s got to be an alternative.

Deming added that… another way to stop the spread of leek moths is by not sharing bulbs.

“They will live in the bulbs and plants over the winter, so sharing them will lead to spreading,” Deming said. (The Valley News)

I can certainly avoid passing our bulbs along, but the leeks were planted from seedlings. Am I in danger? Please pass along any suggestions!