Marine Invasive Species
Another area we have direct involvement in is the growing concern over aquatic invasive species. Invasive species are non-native species that rapidly proliferate within an area, entering due to man's intervention rather than natural spreading mechanisms. For the marine environment, this usually involves species that "hitchhike" a ride from far-off ports on the hulls or in ballast compartments of ships, including recreational and commercial vessels. If mobile, they can drop off the ship in their new home, and some can reproduce and release young even when still attached to the ship. When such species do not have local predators controlling the growth of their populations, their population may explode, causing significant disturbance of the native flora and fauna. Native species may be outcompeted for space and food sources. Some invasive species come from polluted harbors, and are more resistant to pollution impacts like hypoxia (low oxygen). This has become an issue of global concern, with federal laws now developed to control introductions through sources (called vectors) such as ballast water from large ships.

In August 2000, the NBEP, in conjunction with the RICRMC and the NBNERR, helped with logistical coordination of a "Rapid Assessment Survey" (RAS) of marine invasive species in the "fouling community" normally found growing underwater on floats and docks. Stations at 13 floating docks spread across the length of Narragansett Bay from the Seekonk River to Newport were sampled by a national group of taxonomists skilled at identifying native and non-native marine species. A list of non-native species (including some considered "invasive") was developed. A smaller survey of a subset of these initial stations was repeated in August 2003. The Mass Bays NEP Program and MIT SeaGrant and RISeaGrant provided funding for both these efforts. The results of these surveys are available at the MIT Seagrant website:

In December 2002, Dr. Deacutis of the NBEP identified a tunicate (Didemnum sp.) beneath the URI dock on the Bay campus). This species is thought to be a threat to shellfish aquaculture, and has been a problem for mussel aquaculture in New Zealand. The NBEP has been following what is known about this species' distribution in RI through contact with researchers in the area who have concentrated their work on this species. A web page specializing in this species is found at:

The most commonly observed large-sized invasive species in our waters include the Green Crab (Carcinus maenus), which came here long ago (in the 1800s during the colonial shipping period), as well as other successful visitors like :

You can learn more about marine invasive species here:


The newest invasive species;
Chinese Mitten Crab ("Eriocheir sinensis")

"Grateloupia turuturu" is an
invasive red macroalgae

"Coduim Fragile", also known as "dead man's fingers" is another invasive species.

© Narragansett Bay Estuary Program | 235 Promenade Street - Suite 310 | Providence, RI 02908 | 401-633-0550 | Credits