Category Archives: Lake Life

Life on and in Lake Champlain

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

 

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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.

Caspian Tern Population Growing on Lake Champlain

Caspian Tern

Caspian Tern and lake ChamplainHydroprogne caspia

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The Caspian Tern, Hydroprogne caspia, is the largest tern inhabiting the Lake Champlain Basin, and is, in fact, the largest tern in the world. After Double-crested Cormorants denuded parts of Island C of Lake Champlain’s Four Brothers Islands in eight years ago, Caspian Terns found the bare ground appealing and began nesting there.

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Newcomers to Lake Champlain

Caspian terns and Lake Champlain

Four Brothers Islands, Lake Champlain

Relative newcomers to Lake Champlain – the first recorded nesting was in 2001, when a pair was found on Young Island, off of North Hero and on Popasquash Island, off shore between St. Albans and Swanton. By 2004 Caspian terns began nesting on Four Brothers Island and as of 2007 that colony had 50 pairs of birds. The island now hosts over 100 nesting pairs – a ten-fold increase since they were first confirmed on Island C ten years ago.

Although the Caspian Tern is rare to Lake Champlain, it is not listed as threatened or endangered in either Vermont or New York. Much of the Caspian Tern’s core population is found in the Great Lakes region, but that population is suffering from avian botulism, which is killing thousands of terns. Lake Champlain hosts the only Caspian tern colonies in Vermont and the only other New York colony is on Little Galoo Island in Lake Ontario..

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Caspian Tern Characteristics

caspian tern on lake champlainThe same size as gulls, and with similar white plumage, Caspian Terns has bright orange bills and swept-back black crests. They are one of three species of terns that can be found on Lake Champlain.  They can be found throughout much of the world, but rarely in large numbers. While hunting, terns dive down on prey, un-like most gulls. They also hunt with their heads lowered to the water, a posture quite different from soaring gulls. Their voice, a raspy ‘kowk’ also differs from that of gulls. While Caspian terns have increased in number, their cousins, common terns have faced troubles.  In the late 1960s, between 300 and 400 pairs of common terns nested on Lake Champlain, but by 1988 the population had fallen to just 50 pairs. The species is currently listed as ‘Endangered’ in Vermont and ‘Threatened’ in New York. The birds nest on small rocky islands in the lake. Work by Audubon Vermont, the Vermont Non-game and Natural Heritage Program, and the Lake Champlain Land Trust has increased the number of nesting terns since the late 1980s and now between 160 and 200 pairs nest on the lake.

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Interesting Trivia About Caspian Terns:

Caspian Terns may begin to vocalize while still in the egg. When an adult gives a ‘Fish Call’ signaling their return to the nest with food, the soon-to-be chicks may respond with begging calls before they are even hatched.

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How You Can Prevent Invasive Species Expansion

We’ve examined the vast variety of invasive species that are posing threats to Lake Champlain’s ecosystem. By now you’re wondering , “What can I do to prevent invasive species expansion?”

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What Can You Do?

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Boat Owners:

  • Inspect your boat for zebra mussels

    Inspect your boat

    If you are a boat owner, make sure whenever you move your boat from one body of water to the other that it is free of zebra mussels, one of the most dangerous and invasive of all the species. The larval stage of zebra mussels is microscopic in size so you cannot necessarily see them.

  • Clean your boat off when it has come in contact with infested bodies of water, and give it a good look over. Throw any zebra mussels you find in the trash.
  • Remove all mud, plants, or animals and dispose of on dry land.
  • Drain all bilge water, live wells, bait buckets, and all other water from your boat, engine and equipment.
  • Wash all parts of your fishing gear and boat that have been in contact with water. Do not allow wash water to flow into any body of water or storm sewer.

  • Drain all water from the boat, including the bilge, live well, and engine cooling system. Dry the boat and trailer in the sun for at least five days, or if you use your boat sooner, rinse off the boat, trailer, anchor, anchor line, bumpers, engine, etc. with hot water or at a car wash.

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Anglers:

  • Don’t move fish from one body of water to another.
  • Never release unused bait fish, even in waters where using them is allowed.
  • Never move fish overland, unless they have been certified as being disease-free.
  • Make sure that your boat and equipment are clean and dried before using them in a different waterway.
  • Inspect all parts of your fishing gear, boat, and trailer that have been in contact with water.

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Everyone:

  • Purchase non-invasive plants and fish for your landscapes and aquarium.
  • Don’t release unwanted plants or animals into the wild.
  • When swimming or boating in an area infested with Eurasian water milfoil, try not to break parts off the plant—this is how the plant spreads.

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Additional Infomation:

Invasive Aquatic and Wetland Animals (Invasive Species) by Suellen May
Invasive Aquatic and Wetland Plants (Invasive Species) by Suellen May
Invasion Ecology by Julie Lockwood, Martha Hoopes and Michael Marchetti
Invasive Plants: Guide to Identification and the Impacts and Control of Common North American Species by Sylvan Ramsey Kaufman and Wallace Kaufman

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