The top environmental priority of the Long Island Sound Study is reducing nitrogen loads which contribute to the low levels of oxygen affecting substantial areas of western Long Island Sound in late summer. While not affected by the problems plaguing urbanized coastal regions, the PEP has experienced changes in land use and natural resources which have contributed to areas of degraded water quality.
Brown tide is a bloom of marine microalgae, or phytoplankton.
When present in large numbers, the brown tide organism literally turns the water deep brown, making it unappealing to swimmers and fishermen alike. While not harmful to humans, the presence of the brown tide is a problem for bay scallops, and to a lesser degree hard clams, finfish and eelgrass. Soon after the blooms began in the mid-1980s, the population of bay scallops declined significantly, leading to a near collapse of the commercial shellfishing industry in the Peconics.