Sessile Consumer

In conducting my research, I observed activity on a rocky shore off the coast of Washington in the Northwest United States (workbook). This environment inhabits 10 species in shallow water nearly on top of each other. Each species helps form a complicated ecosystem where species protect, consume, and compete for space with other species. Out of the 10 species there are three producers, three sessile consumers (otherwise known as filter feeders), and four mobile consumers- one of which is an invasive species. In this environment the producers are Nori Seaweed (Porphyra), Black Pine (Neorhodomela), and Coral Weed (Corallina). Producers make their own food through sunlight, so only have predators and competition for space. Coral Weed is the strongest

competitor for space, followed by Black Pine, and lastly Nori Seaweed. The producers’ predator is Chiton. The sessile consumers consist of Goose Neck Barnacles(Mitella), Acorn Barnacles(Semibalanus), and Mussels(Mytilus).

The sessile consumers are those that are stationary and all feed off small plankton creating competition for their food source which allows some sessile consumers to be more dominant than others. Mussels are the most dominant between the sessile consumer with the Starfish as its predator, followed by Goose Neck Barnacles whose predators are Whelk and Starfish, and Acorn Barnacles whose predators is Whelk. The mobile consumers consist of Whelk(Nucella), Chiton(Katharina), and Starfish(pisaster). The mobile consumers, which are the the species that have a possibility to be the Keystone species are predators and compete for food. The Starfish preys on Mussels and Goose Neck Particles, the Whelk generally prey on Acorn Barnacles and Goose Neck Barnacles, and the Chiton prey on Nori Seaweed, Black Pine, and occasionally Coral Weed. Between the Mobile Consumers the only competition for food is between the Whelk and Starfish who both prey on Goose Neck Barnacles. Lastly, there is the invasive species known as the Green Crab (Carcinus) which has invaded the environment. The Green crab invades the area and is a predator to all

species. The Green Crab takes over the environment after a short amount of time from its arrival without any possibilities of stopping it. In the environment there is loads of competition between each other. Not only do they compete for food, but they also compete for space. All of this competition creates an interesting environment, yet there is one species that controls the whole environment known as the keystone species.