September 30, 2007

Seeking Non-native Species in New England Waters

A team of researchers led by MIT Sea Grant recently scoured docks and piers from Cape Cod to Maine, searching for non-native species of animals and plants. By collecting, identifying, and cataloguing introduced plants and animals, researchers hope to prevent and control future invasions of non-native species in coastal waters.

In New England coastal waters, the European green crab and Asian shore crab prey on commercially valuable shellfish, while other invasive species damage piers and pilings, clog pipes, damage fisheries and cause public health problems by potentially transporting disease and pathogens. Of particular concern is the recent discovery of the fast-growing sea squirt Didendum on the highly productive shellfish beds of Georges Bank. With the potential to cover the sea floor like a mat, this species threatens to impact scallop fishing.

Judith Pederson, manager of MIT Sea Grant's Center for Coastal Resources and organizer of this survey and two prior surveys in 2000 and 2003, notes that boat fouling and international shipping have accelerated the spread of invasive species. In the latest effort, says Pederson, researchers found sea squirts in areas where they had not been sighted previously. They also discovered a strain of red alga, Grateloupia turuturu as far north as Boston Harbor. This observation marks the first sighting north of Long Island Sound. The alga, which can grow up to three feet, has the potential of out-competing a native algal species (commonly known as Irish moss) with proven economic value.

According to Pederson, who is now analyzing the recent findings, the preliminary data indicate northerly shift of species and a need explore how climate change is affecting the spread of invasives.