Relating Community Composition, Abundance, Growth, and Condition of Aquatic Macrofauna to Watershed Land Use and Shoreline Alteration in Chesapeake Bay

There is growing interest in the ecological effects of shoreline alteration and watershed land use on habitats at the land-water interface, particularly in densely populated coastal zones.  We evaluated how these factors affected dependent aquatic macrofauna (fishes and blue crabs) across over 30 subestuaries spanning the latitudinal extent of Chesapeake Bay.  Watershed land use was assessed for each subestuary, while four replicate shoreline types (beach, marsh, rip rap, and bulkhead) were sampled within a subset of subestuaries to assess local effects.  We examined relationships between aquatic macrofauna, land use, and shoreline type at the community level (composition and diversity), species level (abundance and distribution), and individual level (growth rate and condition).  Economically or ecologically important species (including white perch, mummichog, and Atlantic silverside) were the focus of species and individual level assessments.  Statistical models considered many potential predictors, including land use, shoreline type, availability of benthic forage, salinity, and water quality characteristics; best models were selected using Akaike’s information criterion (AIC).  Both watershed land use and shoreline modification influenced fish assemblages and growth rates. Our findings advance scientific understanding of how human-related landscape and shoreline alterations affect aquatic biota and provide valuable information for resource managers.