Driftwood. It’s one of the most common sights on our New England beaches. But did you ever wonder where it comes from?

Ocean Genome Legacy Director Dan Distel does, and on a recent walk on the beach in Nahant, he found a surprising clue: an unusual castaway hiding in a piece of storm-tossed wood. The unlucky traveler was Teredora malleolus, a small wood-boring clam that is usually found in the balmy waters of the Caribbean. The wood on which the organism stowed away was swept by storms and the powerful warm currents of the Gulf Stream all the way to the chilly shores of Massachusetts.

For this unfortunate clam, this was an ill-fated trip, because it could never survive the frosty New England winter. This kind of thing happens frequently without any harm. But in the future, as our coastal waters warm, this story might have had a different ending—one that could affect our economies and ecosystems.

This “castaway” shipworm in driftwood floated to New England from the Caribbean.

That’s because this castaway belongs to a family of worm-shaped clams, commonly known as shipworms, which burrow in and eat wood. These “termites of the sea” cause terrific amounts of economic loss, destroying wooden boats, pier pilings, and fishing equipment. Will these and other introduced organisms become established as harmful invasive species as our climate warms?

OGL is helping to understand our changing marine environment by preserving genomic samples that help document our oceans as they are today. This baseline information will make it possible to use modern DNA-based methods to measure the changes to come. This tropical castaway is a new addition to our collection, and maybe a harbinger of things to come. Whatever happens, OGL will have the samples needed to document our changing New England biodiversity.