Invasive plants, fish threaten Great Lakes region USA Today (7/9) The first aquatic invasive species in the Great Lakes was the sea lamprey in the 1830s. Now more than 180 species are in the region, and 10 more are "knocking on the door," says a senior policy director for The Nature Conservancy.
Cleaning up the Great Lakes The Voice (7/30) New standards governing the cleaning of ballast water in ocean-going freighters, about to be adopted by the U.S. Coast Guard, should help prevent release of non-native species into the Great Lakes and other threatened U.S. waters.
Eurasian Watermilfoil (Myriophyllum spicatum) was accidentally introduced to North America from Europe. Spread westward into inland lakes primarily by boats and also by waterbirds, it reached midwestern states between the 1950s and 1980s.
In nutrient-rich lakes it can form thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. In shallow areas the plant can interfere with water recreation such as boating, fishing, and swimming. The plant's floating canopy can also crowd out important native water plants.
A key factor in the plant's success is its ability to reproduce through stem fragmentation and underground runners. A single segment of stem and leaves can take root and form a new colony. Fragments clinging to boats and trailers can spread the plant from lake to lake. The mechanical clearing of weed beds for beaches, docks, and landings creates thousands of new stem fragments. Removing native vegetation creates perfect habitat for invading Eurasian watermilfoil.
Eurasian watermilfoil has difficulty becoming established in lakes with healthy populations of native plants. In some lakes the plant appears to coexist with native flora and has little impact on fish and other aquatic animals.
Likely means of spread: Milfoil may become entangled in boat propellers, and may wrap around other external parts of the boat. Stems can become lodged among any watercraft apparatus or sports equipment that moves through the water, including boat trailers.
Habitattitude U.S. Fish and Wildlife Service Adopt a conservation mentality: Protect our environment by not releasing unwanted fish and aquatic plants into the wild. Find out what you can do to help this growing problem on this site.
Invasive Plant Council of New York State This group provides coordination and guidance on the management of invasive plants to protect biodiversity in New York State. Includes a list of the state's top 20 most invasive species, along with photos, and information on biology, range and habitat.