Coastal diversity at Somes Island

This photo demonstrates a diversity of species in the coastal environment at Somes Island. The species present in this photo are quite impressive because they have adapted to survive in an extreme environment that changes on a daily basis as the tide rises and falls. The change in water levels mean that organisms must be able to deal with rapid changes in pH, temperature, salinity, and water availability. In this photo are five different species that have taken residence under a rock. The light purple circle has a type of sea weed inside it. The rose circle emcompasses a tube worm. The orange circle surrounds a chiton. The green ring encircles a closed anenome. Finally the blue circle highlights a snail. Not seen in this photo are crabs and a blunny fish which were present under the rock but not attached to it.

I will now go into some further detail about most of these species. I will be able to give some general facts about the species but I am not able to identify each one specifically. This is mainly because numerous species of these creatures exist and narrowing each to a specific species is not possible with this picture alone.

·      Red algae is a photosynthetic colony that uses sunlight to create its food source. Different algae species use different wavelengths of sunlight depending on their habitat and the availability of sunlight.  It is one of the foundations of the food chain in a costal ecosystem. The loss of photosynthetic organisms in an ecosystem would result in a loss of virtually all other species.

·      The tubeworm most likely belongs to a family known as Serpulidae. There are 300 species in this family. These creatures produce a calcium carbonate shell for protection, which is seen in the photo. Not seen in the photo is the worm itself. It uses feathery looking extensions to filter small food particles out of the water.

·      The chiton is an eight-segmented creature that moves along rock to feed on coralline algae. Its iron reinforced tongue is perfectly adapted to scrape algae off rocks all day long. Crabs, fish, and anemones prey upon chitons.

·      Sea anemones are cnidarians that feed on fish, shrimp, chitons, and plankton. Basically, anything small enough to be stung and captured by its tentacles will fall victim to sea anemones. This one is closed because the tide had move out. It was trying to conserve water and survive until the water level rose with the next high tide.

·      Snails were abundant all over the rocks in both high and low tide areas. They conserve water by remaining stuck to rocks until water levels rise again. They mostly feed on algae and seaweed. Since there were so many snails, it seemed likely that they serve as another important part of the coastal food chain and are preyed upon by crabs, fish, and shorebirds.

·      Crabs were present under rocks all over the beach. These crabs were relatively small and ranged from the size of a pencil eraser to the size of a thumbnail. There are several species of crab, which have adapted to survive on different food sources. Some are scavengers while others feed on plankton or other shellfish. Each species fills a niche in the ecosystem and their abundant numbers allows them to be a large food source for fish, birds and octopus.