Evaluating habitat-fishery interactions: The case of Submerged Aquatic Vegetation and Blue Crab fishery in the Chesapeake Bay

This paper investigates habitat-fisheries interaction between two important resources in the Chesapeake Bay: blue crabs and Submerged Aquatic Vegetation (SAV). A habitat can be essential to a species (the species is driven to extinction without it), facultative (more habitat means more of the species, but species can exist at some level without any of the habitat) or irrelevant (more habitat is not associated with more of the species). An empirical bioeconomic model that nests the essential-habitat model into its facultative-habitat counterpart is estimated. Two alternative approaches are used to test whether SAV matters for the crab stock. Our results indicate that, if we do not have perfect information on habitat-fisheries linkages, the right approach would be to run the more general facultative-habitat model instead of the essential-habitat one. Failure to do so can result in model misspecification and upward-biased estimates of the impact of habitat on species productivity. With our data we fail to reject the null hypothesis that SAV is irrelevant for crabs in the Bay.