Aquatic invasive species are nonindigenous plants, animals, algae, fungi or pathogens – disease causing organisms like viruses and bacteria – that threaten the diversity and survival of native species or the ecological stability of infested ecosystems, or commercial, agricultural or recreational activities dependent on these natural resources. They are a form of biological pollution.
Why do invasive species do so well? They are opportunists not historically known to our region. Most come without the natural checks and balances – predators, pests, parasites and pathogens – that keep species’ reproduction and survival well balanced in their native regions. Many have the advantage of thriving in a wide variety of conditions. Native species find it hard to compete with such invaders.
At least 49 aquatic non-native species are known from Vermont. While many of these species have not become invasive, a significant number have, including Eurasian watermilfoil, zebra mussels, water chestnut, and purple loosestrife. Many of the state's waters, especially lakes, have a history of impacts related to these invasions.
Preventing new aquatic invasive species from being introduced to and established in Vermont is critical, not only to limit the future cost of managing invasive species but also to protect the integrity of Vermont’s ecosystems. Programs aimed at preventing the spread or introduction of invasive species into Vermont are the best and least costly means of protection available.
For more information:
Vermont Department of Environmental Conservation’s Aquatic Invasive Species Program http://www.anr.state.vt.us/dec/waterq/lakes/htm/ans/lp_ans-index.htm
Vermont Invasive Patrollers http://www.anr.state.vt.us/dec/waterq/lakes/htm/ans/lp_VIP.htm
Lake Champlain Basin Program http://lcbp.org/
Photo: Variable-leaved Watermilfoil. VT DEC.