Meeting Abstract

76.2  Tuesday, Jan. 6  Project Limulus: What long term mark/recapture studies reveal about horseshoe crab population dynamics in Long Island Sound. BEEKEY, Mark A.*; MATTEI, Jennifer H.; Sacred Heart University; Sacred Heart University beekeym@sacredheart.edu

Project Limulus is a long-term study of the population dynamics of the American Horseshoe Crab, Limulus polyphemus, in Long Island Sound (LIS). Since 1997, we have tagged over 20,000 spawning adults ranging from Brooklyn, New York to Narragansett Bay, Rhode Island. Over 2000 individuals have been recaptured (9.3%). Analysis of recapture patterns indicates that both males and females exhibit moderate site fidelity within spawning seasons. However, across spawning seasons, only 45% of individuals are recaptured within a few miles of their original tag site. There is no significant difference between males and females with respect to the direction or distance of movement post spawning. Male and female horseshoe crabs appear to move east and west of the tag site with equal frequency. Of all recaptures, 99% of individuals were recaptured within LIS. The mark recapture data supports the idea of a closed population. Within LIS, individuals cross state lines supporting the need for the development of an integrated multi-state management plan. Finally, this past year we collaborated with many groups from MA and RI to conduct coordinated horseshoe crab spawning surveys on the new and full moons along the New England coast. Preliminary findings reveal similar spawning indices, sex ratios, and mating patterns across CT, the north shore of Long Island, RI, and MA beaches.