NATURE NOTES FROM ACADIA

BETWEEN THE TIDE-MARKS

Early on the morning of August 25, Dr. A. E. Brower, Mr. Frank Campagnia, a student at the Mount Desert Island Biological Laboratory, and I boarded a dory at Salsbury Cove and made for the old coaling station at Lamoine, just across the bay. On the previous night the moon had been full, and the tide was now exceptionally low, a condition ideal for collecting a host of stranded marine invertebrates. After circling about in a heavy fog we finally saw the old giant wharf piles of the coaling station and soon were manouvering about scraping a host of congested creatures from the piles in the very shallow water. Here barnacles (Balanus), mussels (Mytilus and Modiolus), sea cucumbers (cucumaria), starfishes, hydroids, sea squirts (Molgula) and others were present in great numbers while anemones (Metridium, etc.), sponges (Halichondria, etc.) and snails of various kinds were to be found.

The struggle (?) for existence in the very narrow and heavily populated habitat between the tide marks is undoubtedly acute. In many areas it becomes to a large extent a keen competition for a place of anchorage. Food is most important, but since the great mother ocean has more than enough for a million million mouths a place of lodgement to which the inexhaustable supply may be brought is the prime requisite. On wharf piles at very low tides one finds layer upon layer of marine creatures, often a heterogeneous group the individuals of which endeavor to hold their own in spite of constantly encroaching forms.

- Arthur Stupka