Zebra Mussel

Zebra Mussel

Dreissena polymorpha

Size: to 2"

Habitat: grows profusely on any solid surface

Zebra Mussel

Notes: Zebra Mussels were introduced into the Great Lakes in the mid-eighties from the Caspian Sea region of Eurasia. They probably arrived as larvae in the ballast water of visiting ships. Since then, they have been having a regular party - spreading like wildfire and often covering every available hard surface, including each other. This wreaks havoc with power-plant cooling systems and municipal water supplies, where masses of the tiny bivalves clog pipes and water intakes. The mussels also radically alter the native lake ecology by efficiently filtering nutrients from the water. This does have one positive effect for divers, however. Apparently, the Great Lakes and surrounding waters have never been cleaner or clearer.

Zebra Mussels
Zebra Mussels growing underneath one of the platforms at Dutch Springs.

Diamondback Terrapin

There are few marine reptiles and even fewer in the cold North Atlantic. While it would be possible for a salt-water crocodile to swim up from the Caribbean, there is no record of one ever having done so. Nor are there any of the sea-snakes that are famous in the South Pacific. The only marine reptiles that are encountered in our waters are sea turtles.

The one exception to this is the little Diamondback Terrapin, Malaclemys terrapin. (right) This small turtle ( about 6 inches ) is found only in salt marsh environments. Adults are very strong swimmers and have even been noted in the ocean surf, although I don't think they venture offshore.