Courtesy of the Vermont Department of Fish and Wildlife.
Courtesy of the Vermont Department of Fish and Wildlife.
They’d speak like old men at the coffee shop of a bygone era when the waters were cleaner and the fish flourished. A time when streams would flush sediments, leaving clean cobbles and gravels for fish to spawn.
They’d reminisce of a time when fall runs of spawning salmon would be seen and spring flows would allow sturgeon to migrate unimpeded to native spawning grounds. A time when the phrase “non-native species” was yet to be used locally.
Unfortunately that bygone era on Lake Champlain is just that — gone.
The influences of a growing country with more people, and an industry to feed its hungry needs, would change the lake’s internal life.
From early settlers in canoes, bateaus and sailing ships, to commercial fishing boats, to barges laden with wood, potatoes and fuel, all had an influence on the big lake’s waters and its inhabitants.
Dams to run sawmills or to create electrical power cut off spawning areas. Pollution spoiled the waters. Invasive species like lamprey preyed on native fish, and over fishing resulted in a great loss in fish populations.
One of the species most affected were the prehistoric monsters of the deep — the lake sturgeon.
Courtesy of the Vermont Department of Fish and Wildlife.
Chet MacKenzie with Sturgeon.
Courtesy of the Vermont Department of Fish and Wildlife.
Once revered for its flesh, caviar, skin for leather and swim bladder for isinglass, the lake sturgeon in Lake Champlain was overfished by the small commercial fishery from 1896 to 1962. As a result, commercial fishing was closed in Lake Champlain 1967.
Habitat loss of spawning areas, overfishing and invasive species are the primary culprits in the loss of this ancient fish.
The American Fisheries Society lists lake sturgeon as threatened in all the states where it lives, including New York State.
The sturgeon was declared endangered by the State of Vermont in 1972. There are no documented Lake Champlain tributary sturgeons spawning waters in New York, only in Vermont. In New York, lake sturgeon have been collected in the St. Lawrence River, Lake Ontario, Lake Erie, the Niagara River, Lake Champlain, Cayuga Lake, the Seneca and Cayuga canals, and in the Grasse, Oswego and Oswegatchie rivers.
Vermont’s four big waters are the historical spawning tributary waters for sturgeon in Lake Champlain. Limited spawning still occurs in the Winooski, Lamoille, Missisquoi rivers and Otter Creek.
Courtesy of the Vermont Department of Fish and Wildlife.
Chet MacKenzie and Tyler Brown, with the Department of Fish and Wildlife, motor up the mouth of the Winooski River to look for sturgeon in Lake Champlain.
Courtesy of the Vermont Department of Fish and Wildlife.
Releasing sturgeon back into the lake
Life history
Sturgeons are the largest and oldest living fish in Lake Champlain, with some living to 150 years or more and reaching weights of 100 pounds or more. Lake Champlain fish average about 4 1/2 feet long. This shark-like looking fish, with long a snout and whiskers called barbels, feeds on the bottom. Lake sturgeon feed on a variety of organisms including leeches, snails, clams, small fish and algae.
Sturgeon have plates on their backs called scutes and leathery skin to protect them.
Prehistoric looking? Yes, because they are. These fish swam when the dinosaurs roamed the lands along old geologic shorelines.
The fish are also in no hurry. They are slow to mature and long lived. The females reach sexual maturity at around 14 years old or even later, while the males reach maturity around eight years or more. Females can live up to 80 years while males may reach 55 years of age. Sturgeon are intermittent spawners. Females may spawn every four to six years.
Lake sturgeon spawn in the spring, from May to June. Stream temperatures of 50 to 60 degrees start the process. They spawn in clean cobbles and rocky bottoms with swift moving water from two to 15 feet deep. Two to three feet per second flows seem to be the optimum rate. The females cast out thousands of sticky eggs that attach to the substrate. Incubation takes around a week or two depending on the water temperatures. The yolk sack live in the void spaces between the rocks until they become larvae, then slowly drift downstream.
The fry inhabit sandy, gravel bottom areas of the stream with lower velocities feeding on fly larvae and baetidae mayfly nymphs. The young fish grow rapidly to seven inches the first growing year. Sturgeon prefer clean sand, gravel or rock bottom areas where food is abundant.
Courtesy of the Vermont Department of Fish and Wildlife.
Chet MacKenzie and his team pulling nets in the ‘Sturgeon hole’ below Peterson Dam.
Future survival
To increase the sturgeon population in Lake Champlain three simple, but effective long-term measures need to be implemented and maintained. Invasive species control, reconnecting spawning and nursery habitat, and maintaining the run of the river flows, are critical to this fish’s future.
Invasive species control is vital. The lamprey affects sturgeon as well as salmon and need to be controlled. Sturgeon were found with an average of 2 .5 wounds per fish. Adults can handle the wounds better that younger fish. Lampreys literally suck the life out of young fish. Lampreys are probably the number one cause of sturgeon mortality at this time and inhibit their recovery.
Studies show that the habitat for sturgeon presently can allow natural reproduction, but at a very slow rate. Dam removal would increase the spawning areas and possibly allow access to nursery areas. One such dam is the Swanton Dam on the Missisquoi River. Originally there were 15 1/2 miles of spawning habitat, which was reduced to 8 miles when the dam was built. The dam is not currently being used for electrical output, flood control or navigation, so it could be removed with no negative impacts, only positive ones.
Otter Creek is open to the falls in Vergennes, which is the natural barrier for the fish. However, dredging in the early 1900’s removed much of the spawning habitat that the sturgeon need. With the dam on the site, sediment flow into the lower river is restricted, so spawning habitat is not created or renewed by the river’s natural actions of transporting sediment downstream.
The Lamoille and Winooski rivers have working dams, so removal is not an option at this time.
However, maintaining the run of the river flows would keep waters flowing during spawning events.
Maintaining run of the river flows stabilizes the stream velocities. Hydro electric operations cause fluctuations in the stream flow. Velocities of the river go up and down. High velocities can flush out spawning sites and move both eggs and young fry downstream. The high water output and velocities also raise and lower water heights in the river scouring out aquatic insects and other invertebrate’s that fish feed on. Low water flows could impact spawning areas that supply oxygen to eggs and young fish, reducing their numbers drastically. Maintaining a more natural run of the river would reduce the negative impacts.
Courtesy of the Vermont Department of Fish and Wildlife.
Chet MacKenzie and Jon Kimball with Sturgeon, Otter Creek.
Monitoring
To ensure the sturgeon have a future, Vermont has taken the lead on sturgeon recovery. Vermont Department of Fish and Wildlife biologist, Chet MacKenzie has set up a program where researchers can gill net sturgeon and trap eggs and larvae. His team also uses high tech equipment to monitor the sturgeon’s movement throughout the rivers during spawning and its natural movements while in Lake Champlain pre and post spawning.
By capturing sturgeon with gill nets, the team is able to record weights and lengths, get DNA samples, tag fish and determine their health before the fish is released. The tagging allows researchers to show that sturgeon can vary their spawning rivers. One fish was tagged in the Winooski and then later netted in the Lamoille a year later.
Egg traps and larval drift nets give the biologists an idea of if and when the fish are spawning, preferred water temperatures and flows for spawning and the time of larval drift. Monitoring equipment has changed like all other high tech equipment. Simple tagging replaced by electronic tagging. Surgically implanted transponders and radio transmitters allow biologists to record and monitor migratory patterns and movements, plus habitat use.
What MacKenzie and other biologists are doing with this unique fish is exceptional. Simple actions like controlling lamprey, removing old dams to allow spawning and maintaining a run of the river flows are critical.
The hand of man can both hurt and heal. Actions of the past have reduced the sturgeon to endangered levels, but a sound scientific hand can make the recovery of sturgeon a reality — which is exactly what the dedicated biologists on both sides of Lake Champlain hope to someday achieve.
Like to learn more?
If this interests you, check out this video site for some cool information about Sturgeon: www.vtfishandwildlife.com/cms/One.aspx?portalId=73163&pageId=282754.
Much of the information in this article was gleaned from Eileen Stegemann’s article: “Sturgeon, the King of Freshwater Fishes,” which can be found on the NYS DEC website or in the “The Lake Champlain Lake Sturgeon Recovery Plan,” by Chet MacKenzie, which is a well-written and easy to understand report about this amazing and unique fossil fish that calls Lake Champlain home.
