Scientists Look for Ocean Intruders

By ANN S. KIM Staff Writer

A crustacean the size of a grain of rice was among the hundreds of specimens that researchers gathered in recent days from docks and piers from Cape Cod to midcoast Maine.

The tiny crustacean, the marine version of a pill bug, didn’t seem like anything they had seen before in their search for invasive species in the area.

"If I can’t nail it down, I’ll bring in some colleagues," said James Carlton, director of the Williams-Mystic Program, a maritime studies program in Connecticut. If the animal, which was found in Portland and Walpole, is not known in New England, Carlton said he’ll keep reaching out until he figures out what it is.

On these surveys, the researchers hope that they won’t find anything new. Such a discovery means an invasion of a non-native species that could threaten the local marine environment as well as the economy and public health.

On Monday, the researchers wrapped up three days in Maine, where they collected specimens in Portland, South Portland, Walpole, Boothbay, Camden and Rockland.

"They’re all different kinds of organisms – plants, animals, bacteria and all kinds of things – that historically did not live in this world that have been transplanted here. … They can totally wreak havoc," said Karen Young, director of the Casco Bay Estuary Partnership, part of the Muskie School of Public Service and the coordinator of the Maine portion of the research.

The Massachusetts Bays Program and MIT Sea Grant coordinated the larger effort.

Non-native species can be introduced to an area in various ways. They may catch rides on pleasure boats or in the ballast tanks of cargo ships that are filled in one port and emptied in another. The live bait and seafood industries also bring animals to new places, where people sometimes release them.

Invaders such as the European green crab eat up shellfish that might otherwise go to market. A variety of sea squirt threatens to overwhelm scallop beds. A type of red algae can shade other plants below.

At the University of Southern Maine lab where the researchers were examining and cataloging specimens, a half-inch splotch marred the shiny green surface of a piece of kelp. The mass of membranipora membranacea, a moss animal from Europe, could have grown to completely cover the kelp blade.

"If you were to wipe out kelp," said Larry Harris, a professor of zoology at the University of New Hampshire, "fish, crab, lobster – what have you – have less habitat to live in."

Harming kelp also hurts others on the food chain because the plant feeds many different organisms, he said.

On one table, a plastic bag held orange spongy-looking blobs, each one a colony of sea squirts.

"This one is a real baddie," said Gretchen Lambert, an investigator from the University of Washington Friday Harbor Labs.

It was a variety of the didemnum sea squirt that Lambert wanted to identify further. She thought it might have originally come from Japan, and was planning to examine Japanese specimens from the Smithsonian Institution and Japan to compare.

This sea squirt covers more than 200 square kilometers of Georges Bank.

The researchers found it in abundance in Walpole and Boothbay, though the population near fresh water seemed to have suffered from the decreased salinity that resulted from heavy rains and flooding.

This is the second "rapid assessment" of invasive marine species conducted in Maine. The first, in 2003, uncovered 34 introduced species. About 30 were found in this year’s assessment, Carlton said.

If a new invasion is found, the researchers will make recommendations on how to deal with it.

Carlton urged the public to report unfamiliar species to scientists or a nature center. Ideally, these surveys would be conducted every year to get a good sense of what’s going on in the coastal zone.

"I could argue," he said, "every four years is not having our hand on the fine-focus knob."

Staff Writer Ann S. Kim can be contacted at 791-6383 or at:

akim@pressherald.com

[Sidebar]

LEARN MORE ONLINE:

Casco Bay Estuary Partnership news:

www.cascobay.usm.maine.edu/news.html

Census of marine life Gulf of Maine Area Program:

http://tinyurl.com/25pter

Maines marine invasion:

http://tinyurl.com/yo6fl3

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