We’ve looked at fish, mollusks, crayfish and plants that want to make Lake Champlain their home. Here are some other invasive threats to Lake Champlain:.
VHS: viral hemorrhagic septicemia: an often lethal fish disease affecting many species. VHS in the Great Lakes drainage has led to significant restrictions on transporting fish between water bodies. It is so significant that new outbreaks must be reported to the World Health Organization for Animal Health. The disease transmits easily between fish (both individuals and species) and mortality rates seem to be highest in colder waters (37-54 F). Because some fish can be carriers of the virus and show no external signs, the actual presence of the disease can only be determined by laboratory testing.
- Spiny water flea and fishhook water flea:
These two plankton species could drastically disrupt Lake Champlain’s food web. Spiny water flea and fishhook water flea both came from Northeast Europe; they were first noticed in Lake Huron in 1984 and Lake Ontario in 1998. These two species were most likely released with a ship’s ballast water. In 2008 spiny water flea were found in the Great Sacandaga Lake in New York, just upstream from the feeder for the Champlain Canal.
** Since this article was originally published (June 11, 2012), Spiny Water Fleas have been confirmed in the Champlain Canal and in Lake George; both of these waterways are linked directly to Lake Champlain. It now (August3, 2012) seems inevitable that Spiny Water Fleas will become established in Lake Champlain, if they haven’t already.
In addition to competing with the native zoo-plankton, spiny water flea and fishhook water flea are much more difficult for small fish to ingest, and are therefore a poorer food source. The long spines of these species can hook them onto anglers’ lines by the hundreds, making fishing difficult. Eggs and adult water fleas can travel unseen in a boat’s bilge water, bait buckets, and live wells.
Learn to recognize these water-fleas on fishing gear.
Inspect and remove aquatic plants and animals, including gelatinous or cotton batting-like material from lines, especially where they meet a swivel, lure or down-rigger ball connection (plucking like a guitar string helps).
Drain lake or river water from live-well and bilge before leaving access.
Dispose of unwanted live bait and worms in the trash.
Double-crested Cormorants: Cormorants are relative newcomers to Lake Champlain and have since become a concern to wildlife managers. They first nested on Young Island, Vermont, in 1981; then expanded to Four Brothers Islands, New York, by 1984, and peaked at over 20,000 birds by 1999. Population increases were associated with destruction of vegetation and displacement of other birds from nesting colonies of stick nests built high in trees on islands or in patches of flooded timber. .
Gangly Double-crested Cormorants are prehistoric-looking, black fishing birds with yellow-orange facial skin. Though they look like a combination of a goose and a loon, they are relatives of frigatebirds and boobies.
Double-crested Cormorants float low on the surface of water and dive to catch small fish. After fishing, they stand on docks, rocks, and tree limbs with wings spread open to dry. In flight, they often travel in V-shaped flocks that shift and reform as the birds alternate bursts of choppy flapping with short glides..
Obviously, Lake Champlain is a great lake; who could fault these newcomers for wanting to take up residence here? But these invasive species are threats to the health and survival of our native species, and will disrupt the health, recreation and aesthetic enjoyment of Lake Champlain’s human residents. We must protect our lake; so, what can we do…?.
Previous: Invasive Invertebrates ( << Previous )