• Views from Penobscot Mountain summit.

    Acadia

    National Park Maine

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  • Trail Closure: Gorge Path weekdays, 7 am - 4 pm

    The section of the Gorge Path between the Hemlock Path intersection and the A. Murray Young Trail intersection is closed until rehabilitation work is completed. The closure will be in effect Mondays through Fridays only, from 7 am to 4 pm.

  • Bubble Pond Carriage Road closure

    Bubble Pond Carriage Road will be closed to all traffic Monday 9/15- Wednesday 9/17 from the parking lot to Triad-Day Mountain Bridge. More »

Field Guide to Marine Invertebrates - Other

Bright green sponge on rock
Halichondria panicea (sponge)
Halichondria panicea ("crumb-of-bread sponge") is green due to symbiotic green algae called zoochlorellae that live within the sponge. When the zoochlorellae are absent, the sea sponge is orange. This sponge is a filter feeder found in subtidal and lower intertidal zones.
 
Red anemone attached to rock under water
Urticina felina (cnidarian)
Urticina felina ("northern red anemone") is sessile (permanently attached to the substrate). This sea anemone uses its tentacles to gather nearby food particles. It is common in the subtidal zone, but can be found in cracks and tidepools in the lower intertidal zone of rocky shores.
 
Photo by Sarah Hall.

Did You Know?

A girl stands along the stone steps of the Kurt Diederich Path in this historic image taken around 1920.

Acadia National Park contains more than 120 miles of historic hiking trails. Many of these trails were established by local village improvement societies in the late 1800s and early 1900s. Today many of the historic features, such as stonework, are still visible.