April 22, 2013: The Precipice, Orange and Black, Valley Cove, and Jordan Cliffs Trails are closed until further notice because of nesting peregrine falcons. All other trails in the park are open, whether accessible from the park or from state roads.
June 14, 2013: The Western Mountain road loop is now open.
Field Guide to Marine Invertebrates - Arthropods - Crustaceans
Cancer borealis ("Jonah crab") is found in the mid- to lower intertidal zone under algae and among rocks. This predator eats blue mussels and other invertebrates. The remains of this crab are often found in the upper intertidal zone, evidence of bird predation.
Carcinus maenas ("green crab") is found under algae and small rocks, and it eats other invertebrates in the mid- to lower intertidal zones. This crab is native to Europe and is an invasive species. The green crab is smaller than the Jonah crab.
Homarus americanus ("American lobster") is a bottom-dwelling predator and scavenger. The American lobster is found throughout the Gulf of Maine, where it is commercially important. The lobster is found in rocky, subtidal habitats but, rarely, can be observed in lower intertidal pools.
This herbivorous crustacean, an isopod, feeds on a variety of algae including large rockweeds (Ascophyllum, Fucus). It is common in the mid- and lower intertidal zones but is hard to see because its color usually matches the algae it is feeding on. This behavior helps it resist predation by fish. Individuals vary in color from yellow to brown to deep burgundy.
All photos by Sarah Hall, except for American lobster (NPS/Todd Edgar photo).
Did You Know?
From late May to early October, park rangers at Acadia National Park offer a variety of programs to suit every interest and activity level. Programs include walks, talks, hikes, narrated boat cruises, bike rides, and more. Check out the Beaver Log for a schedule of programs. More...