On a boat ride along the Sound's it is easy to note some of the beautiful habits and ecosystems that exist along the shoreline. One flower that people often believe heighten the beauty of the Sound is the purple loosestrife. However, what people often down realize is these pretty purple flowers are actually a biological pollutant in disguise. These non-native aquatic plants were introduced accidentally. These colorful flowers may be beautiful from above, but from underwater their destructive nature can be seen. The purple loosestrife's roots are choking the roots of native plants like cattails that provide salt marsh organisms with foot and shelter.
Connecticut has its share of biological invaders, which can subtly or dramatically alter the Sound's ecosystem. Some of these invaders like periwinkle and the green have been here for so long that ecologists do not know what the natural ecosystem is supposed to look like. Others, such as gypsy moth caterpillars and zebra muscles, threaten the environment and the economy.
Early European settlers introduced periwinkle in the 1840s as a common food source from home. Today these little snails can be found along the rocky shoreline. Ecologists believe these snails dramatically reshaped the costal ecosystem, as they competed for food and space with native organisms. It is believed that if this snail were introduced today it would be a disaster for the Sound ecosystem. The green crab also originated from Europe in the early 1800's. This crab now serves an important role as both a predator and prey in the rocky shore habitat.
Another invasive species that is a nuisance to humans, especially boat owners and fisherman are sea squirts. Sea squirts originated from Asia and California and they attach to anything in the water. They have grape-like, elongated or vase-shaped bodies with two projecting spouts. When poked and prodded they often squirt out water. And to make matters worse they do not serve as a food source for humans or marine organisms.
In addition to animals, plants can also be invasive species. "Deadman's fingers" is a spongy green seaweed from Asia that invaded in 1957. This seaweed can damage entire shellfish beds because it attaches to the hard surfaces of oysters and scallops with a tremendous grip.
How did they get here?
Invasive species can invade an ecosystem in a variety of ways. Some, as mentioned above, were deliberate introduced by humans, usually to serve as a food source. Others accidentally arrived on the bottom of ships or fishing gear. They can also be transported in ballast water or packaging containers that release into open waters, like the Sound. But just because new organisms arrive in the Sound does not mean they are going to survive. Conditions must be just right for organism to grow and develop in its hijacked habitat.