Invasive Sea Squirts Spreading Farther East

Tiny Marine Sea Squirts Mystify Beachgoers
Sea Squirt (tunicate), Photo: U.S. Geological Survey by Dan Blackwood

According to the Ellsworth American, at least 2 species of invasive marine tunicates, known as “sea squirts”, have been discovered in Blue Hill Bay in Maine, perhaps due to warming coastal waters. The squishy, translucent marine organisms are invasive species introduced from Europe and the southern hemisphere. They have spread throughout much of New England and now seem to be making their way farther eastward in Maine waters.

The tunicates grow in large clumps, fouling floating docks, piers, ropes, lobster traps and other submerged structures. They can eventually grow densely enough to smother colonies of oysters, mussels and other shellfish.

Read more about the spread of marine tunicates in coastal Maine.