Mapping and Assessing Critical Horseshoe Crab Habitats of Delaware Bay

The Delaware Bayshore Horseshoe Crab Spawning Habitat Mapping Project consisted of inventorying of the Delaware and New Jersey shorelines of the Delaware Bay to assess the availability and spatial distribution of spawning habitat for horseshoe crabs Limulus polyphemus. Using visual interpretation of high spatial resolution (1 meter or better) color/color infrared digital aerial photography acquired in 2002, we on-screen digitized and mapped several categories of information that are relevant to the Bayshore's value as horseshoe crab spawning habitat: 1) beach type and width; 2) near-shore development; and 3) shoreline stabilization structures. Based on these characteristics and information from the literature, we classified the Bayshore's beaches into five categories of spawning habitat suitability: optimal, suitable, less suitable, avoided and disturbed.CRSSA Report #2006-01Purpose: To assess the availability and spatial distribution of spawning habitat for horseshoe crabs Limulus polyphemus