Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

2013

Journal

Marine Ecology Progress Series

Volume

488

First Page

51

Last Page

63

Abstract

Although numerous small-scale laboratory, mesocosm, and field experiments have demonstrated that abundance, survival, and growth of juvenile fish and invertebrates are higher in vegetated than in unvegetated habitats, the effect of habitat quality (i.e. habitat complexity) within vegetated habitats has not been documented at a broad spatial scale. We examined the relationship between percent cover in seagrass beds (eelgrass Zostera marina, widgeon grass Ruppia maritima, and associated macroalgae) and juvenile blue crab Callinectes sapidus density at a broad spatial scale. We quantified the functional relationship between juvenile density and percent cover of vegetation by sampling in Chesapeake Bay (USA) seagrass beds utilized by juvenile blue crabs in the fall of 2007 and 2008, following peak postlarval blue crab recruitment. Based on Akaike’s information criterion model comparisons, the most plausible model included both percent cover of vegetation and region of Chesapeake Bay. Juvenile crab density was a positive exponential function of percent cover of vegetation, and was augmented by 14 to 30%, depending on year, for every 10% increase in cover. Density was approximately 2 times higher on the western shore of Chesapeake Bay than on the eastern shore. Seagrass bed area, presence or absence of algae, and distance to the mouth of the bay did not significantly influence density. An expected threshold (i.e. sigmoid) response of juvenile density to percent cover of vegetation was not evident, probably because this study was undertaken when recruitment was low, so habitats may not have been at carrying capacity. This study is the first to document the functional relationship between habitat quality and juvenile density at a broad spatial scale for a marine fish or invertebrate, and suggests that the quality of seagrass habitat influences population dynamics.

DOI

doi: 10.3354/meps10417

Keywords

Recruitment · Nursery · Habitat quality · Akaike’s information criterion · AIC model · Population dynamics

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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