Friday, February 13, 2009
Shorebirds Decline Despite Restricted Crab Harvest in Delaware
Each May, shorebirds called red knots congregate in Delaware Bay, the final stopover on the way to their Arctic breeding grounds. Red knots and other shorebirds feed on horseshoe crab eggs, but during the 1990s, increased harvest of the crabs led to a more than 90% decline in the availability of their eggs. In a new study, USGS wildlife biologist Jon Bart and co-authors assessed the effects of the increased harvest on red knots and whether nine years of harvest restrictions has improved their population numbers. Despite the restrictions, the 2007 horseshoe crab harvest was still well above that of 1990, and no recovery of knots was detectable. A program of adaptive management, including monitoring, may provide valuable information that managers need to find the right balance for conservation of the species. For more information, see the USGS news release.
Niles, L.J., Bart, J., Sitters, H.P., Dey, A.D., Clark, K.E., Atkinson, P.W., Baker, A.J., Bennett, K.A., Kalasz, K.S., Clark, N.A., Clark, J., Gillings, S., Gates, A.S., Gonzalez, P.M., Hernandez, D.E., Minton, C.D., Morrison, R., Porter, R.R., Ross, R.K., Vietch, C.R., 2009, Effects of horseshoe crab harvest in Delaware Bay on red knots- Are harvest restrictions working?: BioScience, v. 59, no. 2, p. 153-164. [FullText] Catalog No: 1905
Contact:
Jonathan
Bart,
FRESC,
208-426-5216,
jon_bart@usgs.gov
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