Design and implementation of a survey of commercial blue crab effort in the Maryland portion of the Chesapeake Bay

The Maryland Department of Natural Resources (MD DNR, requires estimates of the fishing effort expended by commercial crab fisheries in the Chesapeake Bay. We designed a three-prong approach to obtaining instantaneous estimates of effort in the bay. We collected field data on the commercial pot and trotline crab fisheries, and telephone surveys for supplementary information. Sampling included similar to 160 stratified random transects for pots each month to obtain estimates of spatially explicit pot densities. Survey stations were modified transects; planar boards were used to delineate the width of each transect. The trotline surveys were performed using both aerial flyovers and roving intercept surveys to quantify the mean number of lines per boat and mean trotline length. We describe methods for merging this information in ways that can be used to estimate effort for similar fisheries.