Within intertidal areas of the Northeastern seaboard of the United States, there is a considerable abundance of crabs. Areas such as salt marshes and shorelines provide various forms of habitat for these populations, each posing various benefits for the crabs. The purpose of our project is to survey the biodiversity of crab populations in an urban island environment. We will conduct our study at Randall’s Island’s restored salt marsh and the surrounding bodies of water. In this experiment, we will be testing the biodiversity of crab species. We will also be able to determine the diversity of species in the aquatic habitats compared to terrestrial habitats at the park. We will test for the habitat preference of fiddler crab species. We will examine the ratio of invasive European green crabs and Asian shore crabs to native crabs across various habitats.