Exploring the shoreline on Cape Cod, particularly after a storm, is often an adventure in new discoveries. Though there are many common plants and animals to be seen, occasionally an unusual specimen can be found.
One of these discoveries is the red alga Corallina officinalis, also called coral weed. What is unusual about this plant is its ability to remove calcium carbonate (lime) from the water and encase itself in a hard, white coating of this lime. When dead, they are all white and look like tiny bones under a hand lens or microscope. Itís this form that you are most likely to find.
Even though they may be covered with lime, the algae are still able to photosynthesize, though probably at a reduced rate. Corallina can sometimes be collected attached to small snails or rocks. After a storm, large amounts of this interesting alga can be found entangled with other seaweeds in the wrack line.
Also in the same wrack line, another interesting organism can be seen.Moss animals, such as the bryozoan Bugula neritina, look like brown, bushy colonies of seaweed. If you look closely with a hand lens, you can clearly see that this is an animal. There are several other species besides Bugula as well which can be found here. They are very common in harbors where they attach to any hard object, and are a fouling nuisance on boats.
However, the real surprise to most people is that Cape Cod has coral living in its waters. Itís not easy to find, and the Cape does not have any coral reefs like those in tropical waters. The animal here is called star coral (Astrangia danae). It can be white to pinkish in color and forms thin crusts on rocks and shells. I have found it washed up on the beaches in Woods Hole. Like other corals, it consists of several individuals in a colony.
Itís always fun to find something rare and unusual along the beach. One method for increasing the likelihood of locating different plants and animals is to examine the wrack line marking the high tide mark. Carefully sorting through the seaweed can reveal many species tangled in this mat. Use a hand lens to spot small animals, and look closely at the seaweed itself. There are often several species that are attached or encrusted on the algae. This microscopic world is often overlooked at the beach. Yet these tiny creatures are an important, vital link in the marine food web.
Copyright Gil Newton 2009 Thanks to Chris Dumas for logo image.