Publication Detail

Stag-structured Matrix Modeling and Suggestions for Management of Atlantic Horseshoe Crab, "Limulus polyphemus," Populations on Cape Cod, Massachusetts.

Sara P. Grady, Ivan Valiela
2006
14 pp.
MITSG 06-04J
$5.50 DOM / $7.50 INT
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The Atlantic horseshoe crab, Limulus polyphemus, is harvested by the biomedical industry for Limulus Amoebocyte Lysate (LAL) a blood compound used to detect endotoxins, for scientific research on vision, and bait for the eel and conch fisheries. They are also subject to sources of natural mortality such as consumption of eggs by shorebirds and stranding. Recently there has been growing concern over possible declines in Limulus populations along the east coast of the United States. We have used stage-structured matrix modeling to improve our understanding of Limulus population dynamics in three Cape Cod estuaries (Stage Harbor, Pleasant Bay, and Barnstable Harbor) with differing harvest pressures. The results suggest that a low level of harvest is sustainable, particularly if timing and size-specificity of the harvest are taken into consideration. The model also suggests that efforts should be made to avoid harvesting crabs prior to sexual maturity, as the population growth rate is more sensitive to changes in survival rate of older juveniles than of other stages. The information the model provides will hopefully assist local and regional fisheries managers in establishing appropriate regulations for the horseshoe crab fishery.

type: Journal, book, proceeding reprints

Parent Project

Project No.: 2003-RC-86
Title: Ecology and Management of Exploited Horseshoe Crab Populations: Stage-structured models, Isotopic and Molecular genetics approaches