Associations between environmental factors and grass shrimp parasites in coastal Alabama

Here, I document the abundance and distribution of four parasites in coastal Alabama that infect the common grass shrimp, Palaemonetes pugio. All four parasitic taxa overlap in distribution and abundance in the southwestern portion of the sampling area (Dauphin Island and Mon Louis Island, Alabama), where an abundance of marsh vegetation can be found. I also developed and tested predictions of the seasonal patterns of the most common parasite, the trematode Microphallus turgidus, in P. pugio populations at rookery and mainland locations. Trematode prevalence on rookery islands was lower than that on the mainland. Using univariate and multivariate techniques, I found that temperature, salinity, eutrophication, and the presence of marsh habitat are factors mediating parasite distribution and abundance in Alabama. Biotic interactions are likely to be as important as abiotic factors controlling host and parasite populations and should be included in future environmental quality analyses.