Since I was a child I have enjoyed the simple pleasures of beachcombing, exploring that part of the natural world that Rachel Carson called ‘the edge of the sea.” For many this is primarily a summertime activity, though I find exploring the winter beach just as fascinating. Undoubtedly this form of recreation in my childhood inspired me to pursue the study of marine biology. We sometimes take small steps at the beginning of any career. But I still haven’t lost the thrill of finding a sea creature, even a very common one, washed up in the wrack line or stranded in a tide pool.
The diversity of life in the sea is amazing, and one can get a sense of such diversity by visiting a sandy or rocky beach, an estuary, or a salt marsh. Each marine habitat has its own characteristic assemblage of organisms determined by specific physical features. Visiting an area at different times of the year, or at high and low tides can reveal numerous plants and animals that are present under certain conditions.
A large cluster of ribbed mussels (Modiolus demissus) can be seen at low tide in the mud flats of a marsh. Clinging tightly to the peat substrate these animals can survive several hours of exposure. When the tide comes in it may be accompanied by large numbers of sea stars (Asterias spp.) which pry open the mollusks and feed on the lower rung of mussels. This in turn opens up new space for the colonization of periwinkles (Littorina littorea), bryozoans, and algae.
The tools for beachcombing are very simple. A small bucket can be used to temporarily contain a specimen for examination. You should return the animal to the place where you found it when finished. I always bring a hand lens with me. It helps with more detailed observations for identification. Some people bring along several field guides to the site, but I’m always afraid of dropping them in the water. Instead, a pocket notebook is handy for brief descriptions and sketches when confronted with an unknown specimen. Of course almost everyone carries a camera or phone for taking photos of anything special.
I never tire of making new discoveries at the shoreline. Occasionally one sees something unique or unusual like a large population of salps washing ashore, or a group of sea cucumbers left high and dry. Maybe you will witness horseshoe crabs laying their eggs, or an algae bloom of an invasive species, or a hundred hungry mud snails feeding on a dead fish. At any rate there is much to learn at these dynamic systems. The changes are everlasting and will provide a lifetime of excitement and interest.
Copyright Gil Newton 2009 Thanks to Chris Dumas for logo image.