The Species in and Around the River


Shorebird at the estuary

horseshoe crabs

Horseshoe crabs in the bay


The Delaware Estuary is a vital ecosystem, creating a habitat for more than 130 species of finfish, clams, oysters, and crabs. The second largest concentration of migrating shorebirds in the Western Hemisphere is found in the Estuary, along with habitat for 15 different species of waterfowl, which total more than 500,000 individuals who either migrate through or spend the winter here. Also found in the Delaware Estuary is the largest population of spawning horseshoe crabs in the world. Each year, the horseshoe crab spawning draws thousands of visitors to Delaware and New Jersey shores.

See below for a more detailed description of the animals you will find in this region.