Connecticut River Coordinator's Office
Northeast Region
Photo of zebra mussels attached to a native mussel - Photo credit:  U.S. Fish and Wildlife Service
Photo of zebra mussels attached to a native mussel. Credit: USFWS

Invasive Species

At least 4,500 non-native plants and animals, including 185 species of fish and 88 species of mollusks, have been established in the United States. The number of exotics here has increased in recent years because of the activities of humans.

Some of these exotics have been welcomed with open arms. For example, people are usually surprised to learn that both rainbow trout and brown trout are non-native to the Connecticut River basin. These fish provide a wonderful recreational fishery and are considered very desirable among anglers.

The problem is that many, if not most, of these new comers have no natural predators, so they can spread and grow at an alarming rate. Through that process, they have the potential to crowd out native species, disrupt local ecology, and sometimes threaten human health.

Aquatic nuisance species are one key factor contributing to the growing number of threatened and endangered fish and freshwater mussels. Nationally, 115 species of fish are listed as endangered, including the Connecticut River’s shortnose sturgeon. Almost 72% of the freshwater mussels in the United States are endangered, threatened or of special concern. This includes the watershed’s dwarf wedge mussel.

Sometimes aquatic nuisance species have other unexpected negative impacts on the economy. The cost of control and management can be astronomical once an infestation has occurred, as is the case with the zebra mussel in the Great Lakes. As a consequence of all of these concerns, Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (Public Law 101-646) to prevent and control infestations.

For these reasons, the U.S. Fish and Wildlife Service and many other groups and agencies, are actively working to educate, prevent, monitor and control aquatic nuisance species. Locally, the New England Invasive Plant Group has a news briefing mailing list. This service will keep you updated on workshops, events and current happenings in this field.


Last updated: September 1, 2010
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