Officially it’s called Didemnum Vexillum. It’s more familiarly known as pancake tunicate, also known as sea squirt, or, simply, pest. And it’s infesting the waters around Eastport.

Because of this infestation, scientists at Fisheries and Oceans Canada’s Biological Station at St. Andrews, New Brunswick, have been checking the waters off Deer and Campobello Islands.

As of October 15 no infestation had been found there, according to Jennifer Martin, a scientist at the station. But she added, “Given the tides and the proximity to the populations in Eastport, there is concern that it could be transported to the Canadian side.”

Staff at Maine’s Department of Marine Resources reported findings in Cobscook Bay but advised contacting a professor at the University of New Hampshire who’s considered an expert.

Biological Sciences Professor Larry Harris said that there is indeed pancake tunicate around Eastport and added, “We found it first in Half Moon Cove near where the old bridge to Eastport used to be and [the late fisherman] Bruce McInnis was the one who told me about it. That was in 2005 and it was still there in July.” Harris described the sea squirt as “an amazing thing to see-and sort of scary.” An invasive species, these tunicates often look like small, colored blobs.

Harris continued, ” It is all over the Cook Aquaculture pier and you can probably see colonies along the side of the float at the pier on the pier side. Every piling on the Estes Head pier has it, and Joe Story is the one who told me about it there and then went out and collected it with a long handled net at low tide to prove it in 2006. We dove there in July with Scott Emery and it was still doing well. We have not seen it near the Waco [diner] where we also collect for urchins, but it is doing very well on the Cobscook side of Eastport and is probably elsewhere in Cobscook Bay.”

How much of a threat is it?

Harris said, “It certainly overgrows all manner of other beasts and could be a real problem for mussel culture in some locations as well as scallops and oysters. They had to go to bottom culture for oysters in the Damariscotta because it clogged lantern nets so bad. It closes down in the winter in most places and could be removed if it is not too well established, but that means finding it early. Managing its impact is about all you can do once it is well established and spreading in an area.”

Bob Gustafson is a freelance writer who lives in Eastport.