Kelly, J. P., Evens, J. G., Stallcup, R. W., Wimpfheimer, D., ,
We measured abundances of wintering shorebird species simultaneously on four control plots and two aquaculture plots from Novemeber 1989 to February 1994 on tidal flats in Tomales Bay, California. Twelve abundance estimates for wach plot were obtained each year. We used analysis of covariance to model the results, controlling for the presence of roosting gulls that may have displaced foraging shorebirds. The analysis included effects related to intraseasonal timing, annual variation, and the presence of aquaculture. The two most abundant shorebird species in Tomales Bay, western sandpiper, Calidris mauri, and dunlin, Catoptrophorus semipalmatus, however, were attracted to aquaculture plots. Four other species showed no preferences for control or aquaculture plots. Evidence of underlying (pre-existing) habitat conditions did not explain these results. We found no differences in species richness or Shannon diversity index between control and aquaculture areas. Our results suggest a net decrease in total shorebird use in areas developed for aquaculture.
Kelly, J. P., J. G. Evens, R. W. Stallcup, and D. Wimpfheimer. 1996. Effects of aquaculture on habitat use by wintering shorebirds. California Fish and Game 82(4): 160-174.