Maine spawning surveys of horseshoe crabs (Limulus polyphemus) continued for a third season in 2003. Survey sites were located in Yarmouth, Brunswick (2 sites), Woolwich, Nobleboro, Damariscotta, Sedgwick, Franklin and Sullivan. The purpose of this project is to establish quantitative baseline data on horseshoe crab populations in Maine as a basis for management of this species. The 2003 season recorded cooler than normal water temperatures through the end of May, which resulted in negligible activity during the initial historical May spawning period. Warmer water temperatures in June supported normal levels of spawning activity, as documented by the June counts. The tagging study on Taunton Bay in Franklin continued for a third year, with more observations (1255) and more individuals observed (900) than in 2002 (1119 and 741, respectively), but fewer than in 2001 (2273 and 1292 respectively). The overall data indicate that horseshoe crab populations are declining at all but two of the sites, both of which are in Brunswick.
Schaller, S.Y., Thayer, P., & Hanson, S. (2003). Maine Horseshoe Crab (Limulus polyphemus) Spawning Surveys, 2003. Portland, ME: University of Southern Maine, Muskie School of Public Service, Casco Bay Estuary Partnership.