Zostera marina
Great Bay averages about in depth, and extensive areas of the estuarine substratum are covered with benthic algae and some vascular plants (seagrasses). Eelgrass ("Zostera marina") beds are an important component of the submerged aquatic vegetation (SAV) community in Great Bay, generally where depths are or less but, due to the slightly greater depth in Great Bay, these are not as ubiquitous as they are in the Barnegat/Manahawkin/Little Egg system to the north. Extensive areas ( of intertidal sandflats and mudflats occur in the bay, a result of the sediment load from the Mullica River and the movement of sand in through Little Egg Inlet.