Closures for Winter
December 2, 2013- Acadia is now in winter mode. Most of Park Loop Road, including Cadillac Mountain Road, is closed. Still open is the Ocean Drive section, from Schooner Head overlook to Otter Cliff Road, and Jordan Pond area via Jordan Pond Road. More »
Field Guide to Marine Invertebrates - Mollusks
Littorina littorea ("common periwinkle") is an introduced snail that is one of the most abundant and important herbivores in the intertidal zone. Littorinids are inactive in winter and become active when temperatures rise in spring.
Nucella lapillus (gastropod)
Mytilus edulis ("blue mussel") is a bivalve that attaches to rock by byssal threads. Blue mussels are filter feeders. During red tides, blue mussels feed on dinoflagellate algae containing saxitoxin in the phytoplankton. This makes the mussels unsafe to eat and causes closures of mussel beds to harvesting. Sea stars and crabs prey on mussels, restricting them to the mid- and upper intertidal zones. Larvae settle onto shores of Acadia National Park in autumn, when masses of young mussels can be observed on the rocky shore.
This limpet is an herbivore that feeds on algal crusts, including those of calcified red algae. It is found in tide pools and the lower intertidal zone. Young individuals are typically brown, but the shell is often worn and white in older animals.
Photos by Sarah Hall.
Did You Know?
Acadia National Park's carriage road system, built by John D. Rockefeller Jr., has been called “the finest example of broken stone roads designed for horse-drawn vehicles still extant in America.” Today, you can hike or bike 45 miles of these scenic carriage roads in the park.