• Eagle Lake covered in snow nearing dusk

    Acadia

    National Park Maine

There are park alerts in effect.
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  • Carriage Roads Closed

    All park carriage roads are closed until further notice to prevent damage during the spring thaw. For more information: (207) 288-3338

  • Trail Closures: Peregrine Falcon Nesting

    Precipice Cliff and Valley Cove areas are closed to all public entry until further notice for peregrine falcon nesting season. More »

  • Blackwoods Campground is open

    Blackwoods Campground is open and is sites are available by self-registration at the campground. More »

  • 2014 Season Openings

    Park Loop Rd, Cadillac Mountain Rd, & Hulls Cove Visitor Center is open. Call (207) 288-3338 or follow us on Facebook (www.facebook.com/AcadiaNPS) for more information More »

  • Jordan Pond boat ramp parking lot is closed for construction

    It's scheduled to reopen on June 28. There may be intermittent openings at the discretion of the contractor. The North Lot parking area will remain open for access to the Jordan Pond House Restaurant & hiking & biking trails.

Field Guide to Marine Invertebrates - Mollusks

Periwinkle feeding on alga
Littorina littorea (gastropod)
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.
 
Green-colored periwinkle feeding on alga
Littorina obtusata (gastropod)
Littorina obtusata ("smooth periwinkle") is often found in the mid-intertidal zone of Acadia National Park on Fucus vesiculosus and Ascophyllum nodosum. This herbivorous snail has a smooth shell but occurs in many colors (e.g., black, brown, yellow, and orange).
 
whelk_bak

Nucella lapillus (gastropod)
The shell of Nucella lapillus ("Atlantic dogwinkle," "dog whelk") varies in color from white to dark yellow, brown, or orange. The Atlantic dogwinkle is abundant in the low intertidal zone. Nucella commonly feeds on barnacles and mussels.

 
Five mussels on rock
Mytilus edulis (bivalve)
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.
 
Limpets on algal crust
Tectura testudinalis (gastropod)
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?

The wide carriage road is lined by the spring foliage of birch trees.

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.