B0497
Title: A state space approach to modeling the influence of seagrass availability on juvenile blue crab population dynamics
Authors: Alexander Challen Hyman - University of South Florida (United States)
Grace Chiu - William \& Marys Virginia Institute of Marine Science (United States) [presenting]
Romuald Lipcius - Virginia Institute of Marine Science (United States)
Abstract: Nursery habitats enhance the growth and survival of juvenile fish and invertebrates by providing abundant food resources and refugia. The quality of nursery habitats therefore influences the success of fisheries management and conservation efforts. However, the quantitative value of these habitats in population dynamics at spatial and temporal scales relevant to management has only recently been emphasized and documented for a few species, but not yet for blue crabs (Callinectes sapidus), despite its being the most valuable fishery in Chesapeake Bay, and the well-documented importance of seagrass meadows on juvenile blue crab vital rates and its influence on adult population dynamics. As traditional population models of this species have lacked consideration of habitat-specific effects or multiple sources of uncertainty, we use multiple sources of juvenile and adult indices of blue crab abundance, in concert with spatiotemporal data on seagrass habitat extent, to develop a two-life-stage state-space model of the effects of seagrass habitat distribution on blue crab population dynamics. Results suggest that seagrass availability increased the carrying capacity of the blue crab population and that long-term maximum sustainable yields could be considerably lower among models with seagrass covariates relative to those that naively ignore seagrass effects.
