Category Archives: Ecology

Ecology of Lake Champlain and how to protect our lake.

Sea Lamprey in Lake Champlain

Sea Lamprey

Petromyzon marinus

Adult sea lampreyThe sea lamprey (Petromyzon marinus) is one of four lamprey species found in the Lake Champlain Basin. Lamprey are eel-shaped fish with a skeleton made of cartilage and they belong to a primitive group of jawless fish called Agnathans. Sea lamprey have smooth, scaleless skin and two fins on their back (dorsal fins). The sea lamprey is parasitic; feeding on other fish by 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 bodily fluids.

Sea lamprey have a complex life cycle. Their first four years are spent as ammocoetes – a blind worm-like larval stage – in the soft bottom and banks of waters that flow into Lake Champlain. They then transform into the parasitic adult stage and enter the lake to feed on landlocked Atlantic salmon, lake trout ; which they prefer due to their small scales and thin skin – and other fish species. After twelve to twenty months in the lake the adults migrate back into the streams to spawn, after which they die.

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Lampreys in Lake Champlain

Moderate numbers of sea lampreys were first noted in Lake Champlain in 1929. The sea lamprey has long been considered a non-native invasive species that entered Lake Champlain during the 1800s via the Champlain Canal. Recent genetic studies indicate that the sea lamprey may, in fact, be native to Lake Champlain.

Three other lamprey species are found in the Lake Champlain Basin. Two are non-parasitic, and although the third species is parasitic, it does not seem to have much impact on the Lake Champlain fish community.

Whether or not the sea lamprey is native to Lake Champlain, it has detrimental impacts on the Lake Champlain fisheries, ecosystem, and human residents that are very significant.

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What Are The Impacts of the Sea Lamprey?

Lake trout with sea lamprey attached.

Sea lamprey have a major detrimental impact on the Lake Champlain fish community, the Lake Champlain Basin ecosystem, the anglers that fish Lake Champlain, and the many people throughout the watershed whose livelihood is directly or indirectly supported by the fishing and tourist industry.

Adult sea lamprey attach to a host fish, rasp and puncture its skin, and drain its body fluids, often killing the host fish. Their preferred hosts are salmon, lake trout and other trout species, however they also feed on other fish species, including lake whitefish, walleye, northern pike, burbot, and lake sturgeon. The lake sturgeon is listed as a threatened species in New York and an endangered species in Vermont and it is likely that sea lamprey are affecting their survival.

Most sea lamprey hosts are native fish species that have been part of the Lake Champlain Basin ecosystem for thousands of years. Additionally many of these fish species are important sport fish, highly prized and sought after by anglers.

Fresh lamprey wound on a fish and the lamprey that was removed from the fish.

Prior to any control measures being taken, catches of lake trout and salmon in Lake Champlain were a fraction of catches in similar lakes, despite intensive stocking efforts. High wounding rates indicated that sea lamprey were having a significant impact on the lake trout and salmon populations, and were preventing the restoration of these native fish species to Lake Champlain.

Studies on the Great Lakes show a 40 to 60 percent mortality rate for fish attacked by sea lamprey. Other studies found that a single sea lamprey can kill 40 or more pounds of fish during its adult life. The abundance of sea lamprey were obviously having significant impacts on Lake Champlain’s fishery and ecosystem.

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Sea Lamprey Control

Liquid TFM applied to a stream during a lamprey control treatment.Due to the severity of the impacts that sea lamprey have had on the Lake Champlain fishery and ecosystem, and the social and economic impacts on the people who live in the Lake Champlain Basin, it was determined that sea lamprey populations should be controlled. The federal and state governments, the agencies that manage Lake Champlain, the various organizations that are concerned with Lake Champlain and the people who live in the Lake Champlain Basin generally agree that it would be irresponsible not to control the sea lamprey population.

.

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The New York State Department of Environmental Conservation, the Vermont Department of Fish and Wildlife and the United States Fish and Wildlife Service formed a cooperative and began an integrated control program to reduce the sea lamprey population in Lake Champlain to  acceptable levels. This program is not attempting to eliminate the sea lamprey from Lake Champlain, but only to reduce the impacts of sea lamprey on the lake’s fishery and restore balance to the ecosystem.

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Control Efforts

Bayluscide being distributed from boat during a lamprey control treatment on a delta.Physical methods of control include the use of barriers that prevent adult sea lamprey from migrating up waterways to spawn and traps to capture adult sea lamprey before they can spawn.

However, the most effective form of control has been the treating of tributaries and deltas with lampricides – TFM in tributaries and Bayluscide on deltas. The lampricides target the larval sea lamprey, killing them before they can transform into their parasitic adult form.

It should be noted that after years of study in Lake Champlain, the Great Lakes, and other places where sea lamprey are controlled using lampricides, 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.

.

Control Program

small map showing the different methods employed to control Lake Champlain sea lamprey with different color codes
(Click on Map to Enlarge)

Evaluation of an eight year experimental sea lamprey control program that took place in Lake Champlain in the 1990s documented significant benefits for fish and anglers. These benefits included decreases in wounding rates on trout and salmon, increases in weight and survival rates of lake trout, increases in angler catch rates of lake trout and a benefit to cost ratio of 3.5 to 1.

At the end of the eight year experimental sea lamprey control program, a limited, three-year interim sea lamprey control program was undertaken from 1998 to 2000. After a thorough environmental review, a long-term sea lamprey control program began in 2002.

Fish sampling programs, salmon returns to fish ladders, angler surveys and sampling of larval sea lamprey are used to measure the effectiveness of the control program. The control program may be expanded to other streams and delta areas if significant sea lamprey populations develop in them.

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Assessments of sea lamprey populations are made before any control measures begin and again afterwards to determine the effectiveness of the controls. Field staff, using a variety of capture methods, sample both adult and larval sea lamprey from streams and deltas to determine the presence and density of sea lamprey populations. This information is used to determine which streams or deltas are in need of control measures and which control measures to use.

Scientists and fish managers continue to consider, other methods to reduce sea lamprey impacts. These include the use of pheromones (chemical attractants naturally produced by lamprey) to capture adult sea lamprey, the release of sterile males to disrupt spawning, and the stocking of lamprey-resistant strains of fish.

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More about Sea Lamprey:

  • Sea Lamprey Events – Schedule and announcements of treatments and other events related to sea lamprey control on Lake Champlain
  • Sea Lamprey Experts – Experts on Lake Champlain sea lamprey discuss the natural history and past, current, & future control efforts

The post Sea Lamprey in Lake Champlain appeared first on Lake Champlain Life.

Sea Lamprey in Lake Champlain

Sea Lamprey

Petromyzon marinus

Adult sea lampreyThe sea lamprey (Petromyzon marinus) is one of four lamprey species found in the Lake Champlain Basin. Lamprey are eel-shaped fish with a skeleton made of cartilage and they belong to a primitive group of jawless fish called Agnathans. Sea lamprey have smooth, scaleless skin and two fins on their back (dorsal fins). The sea lamprey is parasitic; feeding on other fish by 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 bodily fluids.

Sea lamprey have a complex life cycle. Their first four years are spent as ammocoetes – a blind worm-like larval stage – in the soft bottom and banks of waters that flow into Lake Champlain. They then transform into the parasitic adult stage and enter the lake to feed on landlocked Atlantic salmon, lake trout ; which they prefer due to their small scales and thin skin – and other fish species. After twelve to twenty months in the lake the adults migrate back into the streams to spawn, after which they die.

.

Lampreys in Lake Champlain

Moderate numbers of sea lampreys were first noted in Lake Champlain in 1929. The sea lamprey has long been considered a non-native invasive species that entered Lake Champlain during the 1800s via the Champlain Canal. Recent genetic studies indicate that the sea lamprey may, in fact, be native to Lake Champlain.

Three other lamprey species are found in the Lake Champlain Basin. Two are non-parasitic, and although the third species is parasitic, it does not seem to have much impact on the Lake Champlain fish community.

Whether or not the sea lamprey is native to Lake Champlain, it has detrimental impacts on the Lake Champlain fisheries, ecosystem, and human residents that are very significant.

.

What Are The Impacts of the Sea Lamprey?

Lake trout with sea lamprey attached.

Sea lamprey have a major detrimental impact on the Lake Champlain fish community, the Lake Champlain Basin ecosystem, the anglers that fish Lake Champlain, and the many people throughout the watershed whose livelihood is directly or indirectly supported by the fishing and tourist industry.

Adult sea lamprey attach to a host fish, rasp and puncture its skin, and drain its body fluids, often killing the host fish. Their preferred hosts are salmon, lake trout and other trout species, however they also feed on other fish species, including lake whitefish, walleye, northern pike, burbot, and lake sturgeon. The lake sturgeon is listed as a threatened species in New York and an endangered species in Vermont and it is likely that sea lamprey are affecting their survival.

Most sea lamprey hosts are native fish species that have been part of the Lake Champlain Basin ecosystem for thousands of years. Additionally many of these fish species are important sport fish, highly prized and sought after by anglers.

Fresh lamprey wound on a fish and the lamprey that was removed from the fish.

Prior to any control measures being taken, catches of lake trout and salmon in Lake Champlain were a fraction of catches in similar lakes, despite intensive stocking efforts. High wounding rates indicated that sea lamprey were having a significant impact on the lake trout and salmon populations, and were preventing the restoration of these native fish species to Lake Champlain.

Studies on the Great Lakes show a 40 to 60 percent mortality rate for fish attacked by sea lamprey. Other studies found that a single sea lamprey can kill 40 or more pounds of fish during its adult life. The abundance of sea lamprey were obviously having significant impacts on Lake Champlain’s fishery and ecosystem.

.

Sea Lamprey Control

Liquid TFM applied to a stream during a lamprey control treatment.Due to the severity of the impacts that sea lamprey have had on the Lake Champlain fishery and ecosystem, and the social and economic impacts on the people who live in the Lake Champlain Basin, it was determined that sea lamprey populations should be controlled. The federal and state governments, the agencies that manage Lake Champlain, the various organizations that are concerned with Lake Champlain and the people who live in the Lake Champlain Basin generally agree that it would be irresponsible not to control the sea lamprey population.

The New York State Department of Environmental Conservation, the Vermont Department of Fish and Wildlife and the United States Fish and Wildlife Service formed a cooperative and began an integrated control program to reduce the sea lamprey population in Lake Champlain to  acceptable levels. This program is not attempting to eliminate the sea lamprey from Lake Champlain, but only to reduce the impacts of sea lamprey on the lake’s fishery and restore balance to the ecosystem.

.

Control Efforts

Bayluscide being distributed from boat during a lamprey control treatment on a delta.Physical methods of control include the use of barriers that prevent adult sea lamprey from migrating up waterways to spawn and traps to capture adult sea lamprey before they can spawn.

However, the most effective form of control has been the treating of tributaries and deltas with lampricides – TFM in tributaries and Bayluscide on deltas. The lampricides target the larval sea lamprey, killing them before they can transform into their parasitic adult form.

It should be noted that after years of study in Lake Champlain, the Great Lakes, and other places where sea lamprey are controlled using lampricides, 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.

.

Control Program

small map showing the different methods employed to control Lake Champlain sea lamprey with different color codes
(Click on Map to Enlarge)

Evaluation of an eight year experimental sea lamprey control program that took place in Lake Champlain in the 1990s documented significant benefits for fish and anglers. These benefits included decreases in wounding rates on trout and salmon, increases in weight and survival rates of lake trout, increases in angler catch rates of lake trout and a benefit to cost ratio of 3.5 to 1.

At the end of the eight year experimental sea lamprey control program, a limited, three-year interim sea lamprey control program was undertaken from 1998 to 2000. After a thorough environmental review, a long-term sea lamprey control program began in 2002.

Fish sampling programs, salmon returns to fish ladders, angler surveys and sampling of larval sea lamprey are used to measure the effectiveness of the control program. The control program may be expanded to other streams and delta areas if significant sea lamprey populations develop in them.

Assessments of sea lamprey populations are made before any control measures begin and again afterwards to determine the effectiveness of the controls. Field staff, using a variety of capture methods, sample both adult and larval sea lamprey from streams and deltas to determine the presence and density of sea lamprey populations. This information is used to determine which streams or deltas are in need of control measures and which control measures to use.

Scientists and fish managers have considered, and continue to consider, other methods to reduce sea lamprey impacts. These include the use of pheromones (chemical attractants naturally produced by lamprey) to capture adult sea lamprey, the release of sterile males to disrupt spawning, and the stocking of lamprey-resistant strains of fish.

.

More about Sea Lamprey:

  • Sea Lamprey Events – Schedule and announcements of treatments and other events related to sea lamprey control on Lake Champlain
  • Sea Lamprey Experts – Experts on Lake Champlain sea lamprey discuss the natural history and past, current, & future control efforts

 

A Dinosaur Among Us- The Lake Sturgeon

A Dinosaur Among Us- The Lake Sturgeon

 

Like Elvis, dinosaurs are not dead.

A Dinosaur Among Us- The Lake SturgeonDon’t believe me? Well, it’s true…sort of. While they may not be ‘dinosaurs’ per say, they are really really REALLY old.

I’m talking, of course, about Acipenser fulvescens, or the Lake sturgeon as everyone who isn’t trying to sound smart (cough cough) calls it.

A Brief Biology Lesson

As I mentioned, sturgeon are a very old species; fossils have been aged at over 60 million years old. This is evident in that sturgeons do not have calcium-based bones or vertebrae, but rather have a cartilaginous notochord. The only other fish species in the world that still maintains this bone structure are the lamprey.

Lake sturgeons are benthic (bottom) feeders that typically reside over the mud, sand, and gravel of large lakes and rivers. They commonly grow to a length of 3-5 feet and tip the scales anywhere from 20 to 80 pounds. Outside of the Northeastern US, they have been recorded in excess of 7 feet long and weighing more than 300lbs. Lake sturgeon are omnivorous, eating virtually anything that is remotely edible. Prowling the bottom, they use barbels to feel for something tasty. Upon finding something, the fish protrudes its tube-like mouth, sucks the food in, and simply spits out what it doesn’t want.

When sturgeons reproduce in the spring, they put on a show. Groups of adults come together along rocky river banks to perform rituals that include full body rolls, slapping the surface with their tails, and launching themselves completely out of the water. A female can produce 100,000 to 800,000 eggs at a time, which get locked between the rocks as they flow downstream.

Lake sturgeons are one of the longest-living freshwater fish; the oldest on record is 154 years old. This means they are also one of the slowest to reach sexual maturity. It takes nearly 15 years before a female sturgeon can reproduce.

It’s a Hard-Knock Life

Life hasn’t been very kind to the Lake sturgeon. At one time, they were so plentiful in Lake Champlain, they were considered a trash fish. They were a nuisance that fouled up the nets of fisherman trawling for salmon, which were also abundant at the time (notice a theme here?).  Believe it or not, some reports say that in the mid-1800’s, people would catch them to use as fertilizer, or to dry and burn in the winter!

Around 1880, people came to the realization that Lake sturgeon actually tasted pretty good when smoked. Additionally, the discover of isinglass, a gelatinous material found in their swim bladder and used broadly in the culinary world, brought significant fishing pressure on them. By the turn of the century, catch rates had dropped by 80%.

To make matters worse, the sturgeon was dealt a one-two punch of urban and agricultural development. Newly erected dams blocked them from their spawning grounds; toxic PCBs from urban areas caused high death rates; and algae blooms feeding on farm run off sucked the oxygen out of the water.  Catch numbers continued to dwindle until, in 1967, it was closed for good.

Look On The Sunny Side

Lake sturgeons are currently listed as endangered in Lake Champlain, but awareness of this special species is gaining. While no modern stocking program exists for them in Lake Champlain, agencies continue to keep a close eye on them. It is believed that, while slow, the population is rebounding and with proper management of habitat, a stocking program may not be necessary. Genetic sampling has shown that there is a naturally reproducing population that is large enough not to be experiencing any genetic crossover.

 

For more information, please see these links:

http://www.dec.ny.gov/animals/26035.html

http://genome-lab.ucdavis.edu/publications/Welsh_et_al_2008.pdf

http://www.vtfishandwildlife.com/library/Reports_and_Documents/Fish_and_Wildlife/Spawning_Habitat_Suitability_for_Walleye_and_Lake_Sturgeon_in_the_Missisquoi_River.pdf

 

The post A Dinosaur Among Us- Think You Know Champlain? appeared first on Lake Champlain International.

Have You Signed the Petition to Close The Champlain Canal Yet?

Join Over 500 Other Friends of Lake Champlain

Please Sign The Petition to Close the Champlain Canal!

 

Petition to Close The Champlain Canal

Spiny Water flea

The Champlain Canal is a 60-mile long canal that connects Lake Champlain with the Hudson river.  At its peak, it was used by thousands of people to transport goods and for transportation. Today the canal is used mostly by recreational boaters and some commercial vessels.Approximately 20 invasive species have already been introduced to Lake Champlain through the canal, and the spiny water flea threatens to be the next invasive species that invades Lake Champlain. Like other lakes in the U.S., the Lake Champlain ecosystem, including fish and wildlife, and the surrounding economy will be significantly compromised with the invasion of the spiny water flea.  It is estimated that the total annual cost of invasive species linked to the canal is nearly $500 million (Pimentel, 2005; http://bit.ly/Ozpywt), clearly illustrating the economic importance of disconnecting the canal from Lake Champlain.  With 5,000 pleasure boats using the canal each year (Dan Weiller, spokesman for the NY State Canal Corp), it costs $100,000 of public funds per boat to keep the canal open.Numerous options exist to close the canal while accommodating boat traffic. Funding has already been set aside to cover the costs of closing the canal.

Please sign and share this petition to protect Lake Champlain and the regional economy from destructive invasive species.

You can learn more about the effort to disconnect the canal here: http://bit.ly/ChampCanal

You can also read “Feasibility of Champlain Canal Aquatic Nuisance Species Barrier Options” for suggested solutions on how to close the canal:http://www.uvm.edu:8889/~seagrant/communications/assets/ansbarrierrprt06.pdf

The post Have You Signed the Petition to Close The Champlain Canal Yet? appeared first on Lake Champlain Life.

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)

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?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.

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?

Related articles

The post Are Lampreys an Invasive Species? appeared first on Essex on Lake Champlain.