This proposal aims to assess marine biodiversity and estuary health on City Island, NY, by analyzing selected marine organisms such as crabs, worms, mussels, snails, and seaweed. Through DNA barcoding, the study will identify species diversity and detect invasive organisms within the ecosystem. The research involves collecting, photographing, and cataloging specimens on iNaturalist, complemented by field guide identifications. DNA barcoding will follow, with DNA extraction and PCR performed at the Regeneron DNA Learning Center to ensure precise results. The outcomes are intended to inform local conservation efforts, highlighting potential impacts of pollution on species adaptation and survival, thereby contributing to broader ecological preservation initiatives within this vibrant coastal habitat.