Tag Archives: Fishing

Lake Trout Moving “Below the Surface” of Lake Champlain

We at ECHO are fortunate to have a wonderful resource in the UVM Rubenstein Ecosystem Science Laboratory housed with us at the Leahy Center for Lake Champlain.  The “Rube” as its called, is the home of some of the most current research on the Lake and its Basin– all done by a dedicated, interested, and sharing group of UVM faculty, students, and staff.  Among them is Dr. Ellen Marsden, who has been studying lake trout in Lake Champlain for a long time.  As you may already know from our video about Champ, Dr. Marsden has a knack for communicating scientific concepts concisely and in an accessible manner.  Sometimes a moving picture can tell us what words cannot.  For instance, she and her graduate student, Bret Ladago, built a underwater Remote Operated Vehicle (ROV) that is capturing remarkable footage of lake trout staging for spawning in shallow reef habitats in Lake Champlain (for the best viewing, maximize the view):

In this one, several lake trout are “shoaling” — staying in one area where they may later spawn.  Several trout in this small group have adult sea lampreyattached to them; some show wounds from previous parasitism by sea lamprey.  To my eyes, the proportion of fish with either sea lamprey attached or wounds is dramatic; yet overall I only can get a really good look at perhaps a dozen individual lake trout.

In this one, a much larger number of fish are moving past the ROV while “schooling.”  Again, there are signs of sea lamprey parasitism on a portion of these fish.  In this case, I can see that there are many more fish in the area and I can examine many more fish for signs of parasitism by sea lamprey than in the previous footage.

This amazing footage provides never-before-seen glimpses into the appearance and behavior of Lake Champlain’s lake trout.  But yet it is important to understand that these are glimpses- just a very small snapshots of the large population of lake trout.  For example, the shoaling video alone could make us believe that despite our efforts to control the numbers of sea lamprey in the Lake, a majority of fish show signs of parasitism.  The second video may lead us to temper that view somewhat.  More footage might reveal other impressions.  How do we know what the true rate of parasitism of lake trout by sea lamprey is?  Are efforts to control sea lamprey changing this over time?

While the video footage is certainly engaging, its not the best tool for estimating rates of sea lamprey parasitism.  For example, because we cannot always see both sides of the trout, we do not know if individual trout may be seen multiple times.  Furthermore, there appears to be behavioral differences between the sets of footage which might indicate that the fish we see may not be average or typical members of the population.

Fisheries science provides the tools we need to answer these questions.  By actually capturing and examining hundreds of large lake trout in a standardized way, the Lake Champlain Fish and Wildlife Management Cooperative has collected data year after year to provide answers.   According to their data (presented here from Lake Champlain Basin Program’s 2012 State of the Lake Report), rates of wounding on both lake trout and atlantic salmon by parasitic sea lamprey have been declining since 2007:

Taken from: http://sol.lcbp.org/biodiversity_impact-sea-lamprey-on-salmon-trout.html

For 2011 around 40% of large lake trout had scars from infestation of sea lamprey.  Ideally, this rate will continue to drop over time and achieve the 25% target rate set by fisheries managers for lake trout.

There are many reasons that we should care about the health of lake trout populations in Lake Champlain.  As large, deep water fish-eating predators, they exist with Atlantic Salmon as one of the top predators in the Lake, playing a role in maintaining the structure of the Lake’s food web.  By virtue of their size and habitat, they are part of the economic draw to the Lake, supporting the business of fishing guides, equipment sales, and fishing license sales.  Some of these dollars get invested back into conservation activities of our state and federal governments.  Additional public dollars support management activities to control the numbers of immature sea lamprey growing up in local streams and rivers and to rear young lake trout for stocking.  Last but not least, as these videos attest, they are graceful, resilient, and beautiful members of our Lake community.

For more information about lake trout in Lake Champlain, check out this story from UVM’s University Communications series, or visit Dr. Marsden’s website.

Muskellunge Are Back!!!!!!

Lake Champlain is the only lake in New England to which muskellunge (muskie)are native.
According to the Vermont Fish and Wildlife Department, the largest Muskellunge caught and recorded in Vermont was a 38.22 lbs fish taken on September 9, 2005 from the Missisquoi River by Chris Beebe.
Vermont Fish & Wildlife – Fish Transport Vehicle

 

This year ECHO Lake Aquarium & Science Center partnered with Vermont Fish & Wildlife to acquire several juvenile muskie to display in an exhibit in the near future. 
The muskie originated from eggs taken from wild brood stock collected in April, 2012 on Lake Chautauqua in western New York State. 
New York Department of Environmental Conservation’s Chautauqua Hatchery, located  on Lake Chautauqua in Mayville NY, hatched the eggs and grew them to 4 inches for release.  
Currently, the few juveniles at ECHO are 6 ½ months old, but many thousands more were released into Lake Champlain on August 22, 2012.
Juvenile Muskie Ready for Release

 

The released muskie are expected to attain 10 to 12 inches before winter sets in and their growth slows. 

In the hatchery, they have been fed exclusively a formulated pellet diet, but once they switch over to live prey in the lake, their growth rates will be very high. 

In the last 4 years, Vermont Fish & Wildlife have stocked a total of 25,000 of these fish into the lower Missisquoi River and Missisquoi Bay in an attempt to restore a viable muskellunge population to Lake Champlain.   

Here are the actual stocking numbers provided by the Vermont Fish & Wildlife:
Year             #of fish      
2008            250
2009           10,000
2010           0
2011           5,300
2012           8,800
We invite you to come visit the Upper Animal Care (UAC) window on the top floor at ECHO where we have 2 juvenile muskie on display. Come watch them grow!

New Weapon to Combat Sea Lamprey in Lake Champlain

New York State officials are very encouraged about the first results from this newest tool in the fight against Lake Champlain’s sea lamprey pests according to this article from the Glens Falls Post-Star.

This specialized boat and sprayer uses sonar to locate lamprey ammocetes, then targets them with a safer and more specific lampricide than has been used in the past; additionally treatment can be performed during windy conditions.

High-tech methods used to kill invasive lampreys

Biologists have a new weapon against a fish-killing pest in Lake Champlain, and initial results have left state officials optimistic it will greatly assist efforts to protect sport fish in the lake.

The U.S. Fish and Wildlife Service has purchased a specialized boat equipped with a sprayer that allows fisheries experts to more accurately target areas where sea lamprey young are living, said Bill Schoch, the state Department of Environmental Conservation’s regional fisheries manager.

The boat has side-scanning sonar to allow scientists to find the lamprey young, called ammocetes, the pesticide is designed to kill.

“They can find ammocetes with much better accuracy than before,” Schoch said.

The new boat can also be used in windy conditions that in the past have foiled treatment efforts, Schoch said.

“It treats faster and more accurately and can work in rougher weather,” Schoch said. “It’s a remarkable improvement.”

Calls to the Fish and Wildlife Service office in Burlington, Vt., were not returned last week.

Lampreys are voracious predators, attaching themselves to fish and boring through their scales to consume their blood and bodily fluids.

Treatments targeting them have proven effective in curtailing the population. Fish wound rates have dropped from more than 60 per 100 fish to 15 per 100 fish.

The new boat and equipment were used late last month to treat the Saranac River delta, a major lamprey breeding ground, and the result was hundreds of thousands of dead lamprey young, officials said.

The machine also allows the use of a different pesticide that targets only lampreys. A chemical called Bayluscide was used at the Saranac River delta site, when in the past a different chemical called TFM was used, which was applied by a spreader or pump.

Use of TFM has been controversial because the chemical may kill other organisms.

For now, the new computerized equipment can only be used to treat lake deltas and not tributaries, where other treatments using TFM will continue to be done, Schoch said.

In all, two deltas and five brooks are scheduled to be treated this fall, but treatments have been delayed by low water.

Mount Hope Brook in Whitehall, which feeds South Bay, is scheduled for treatment early next month, while treatment of other tributaries further north and on the Vermont side is set into late October.

Mill Brook in Essex County is the only other tributary in the region scheduled to be treated this year. The Poultney River was treated last year but will not be treated this year.

Mount Hope Brook was scheduled to be treated last year, but the water was too high in the wake of Tropical Storm Irene and other rain events.

Click Here to learn more about Lake Champlain sea lampreys

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.

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.

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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.

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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

 

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.