Relationship of Sphaeroma Quoianum to Sediment Characteristics and Invertebrate Community
Abstract Many important wetland functions are tied to sediment dynamics, which are largely governed by infaunal invertebrate communities. These communities are sensitive to changes in sediment structure and to colonization by non-native species. In a southern California salt marsh, the non-native Australian isopod Sphaeroma quoianum has created dense networks of burrows within the marsh banks. Since this isopod increases erosion in many areas and can change local invertebrate communities, its possible contribution to habitat loss in this already-scarce southern California ecosystem is an important question. This study connected S. quoianum burrows to increased proportions of crustaceans, decreased carbon content, and steep marsh bluffs. These results highlight the potential susceptibility of salt marsh habitat with steep edges to invasion by non-native species and demonstrate that such invasion can correlate to key changes in ecosystem function. These results also suggest that S. quoianum invasion of salt marsh habitats can alter native communities and ecosystem functions, thus incipient invasions should be of concern to managers and ecologists alike.