Evaluating Local Lobster Population Dynamics (NOAA, US Army Corps of Engineers)

Evaluating Local Lobster Population Dynamics with Trap-Based Mark-Recapture Sampling and Sea Bed Mapping

Participants: R. Wahle (Bigelow)

Funding agency: NOAA/Sea Grant; US Army Corps of Engineers

Funding Period: 2001-2003

Project Summary:

Seabed mapping, spatially referenced trapping, and mark-recapture methods have all been used independently in ecological studies of lobsters and other benthic animals. Here we integrate the three methods to evaluate local population dynamics and movements of American lobsters, Homarus americanus, in coastal fishing grounds in Maine. The method was applied in proof-of-concept trials supported by Sea Grant and a sediment disposal impact study contracted by the US Army Corps of Engineers. The research provides a means to use traps to obtain direct estimates of abundance via mark-recapture methods, and to validate those estimates by independent diver methods.  Mark-recapture methods give the added benefit of providing estimates of gains and losses to populations, as well as differentiating mortality from emigration. Seabed mapping and diver ground-truthing provided a means to validate abundance mark-recapture-based abundance estimates. The approach could make traps a more useful tool to in stock assessment and environmental impact studies.

Publications/Reports:

Wahle, R.A., O’Donnell, K.P., Dunnington, M.J., Bell, M. 2003. Impact of dredged sediment disposal on lobster and crab abundance and movements at the Rockland  US Army Corps of Engineers, New England District. Disposal Monitoring System. DACW33-03-D-007 TO5 / 09000-351-260 disposal site.

Dunnington, M.J., R.A. Wahle, M.C. Bell, N.R. Geraldi. 2005. Evaluating local population dynamics of the American lobster, Homarus americanus, with trap-based mark-recapture methods and seabed mapping.  N. Z. J. Mar. Freshw. Res. 39: 1253-1276.

Geraldi, N.R., Wahle, R.A. Dunnington, M.J. 2009. Habitat effects on American lobster catch and movement: Insights from geo-referenced trap arrays, seabed mapping, and tagging. Can. J. Fish. Aquat. Sci. 66: 460-470.