Macrofaunal Community Patterns of Adjacent Coastal Sediments with Wave-Reflecting or Wave-Dissipating Characteristics

Abstract Sandy coastal sediments in similar wave-exposure conditions in southeastern New Zealand supported different macrofaunal communities in an area with steeply sloped bathymetry compared with an adjacent area with a shallower slope and, therefore, a more wave-dissipating profile. Assemblages were sampled in autumn and spring along three shore-normal transects (6–30 m water depths) in two areas separated by a small headland. There was no sediment texture stratification in surficial sediments and no seasonal variability in sediment texture. Macrofaunal abundance and taxon richness were higher in both areas in spring. Taxon richness generally increased with depth in both communities. Abundance increased with depth at the more reflective site but decreased with depth at the more dissipative site until a possible autecological point was reached, whereafter both abundance and richness continued to increase with depth and community composition merged into a typical shelf community. This merge point supports...