Taxonomic and functional assessment of mesopredator diversity across an estuarine habitat mosaic

A long-standing rule in ecology is that structural complexity increases abundance and diversity of organisms, but this paradigm glosses over potential trait-specific benefits of habitat structure across different regional species pools. We tested this idea using multiple response variables emphasizing taxonomic and functional diversity in seagrass-vegetated, edge, and unvegetated habitats across three estuaries in Washington State (USA). We also used these variables in tandem to evaluate functional redundancy as a proxy for ecosystem resistance and resilience. The estuaries spanned a two-fold range in richness of mesopredatory fishes and decapods. Increases in per-sample abundance with habitat structure were confined to three of seven functional groups, specifically those occupying the water column or directly associated with seagrass shoots. Consequently, seagrass reduced mesopredator diversity by reducing evenness. Habitats differed in mesopredator assemblages despite their spatial ...