Sampling effort to characterize estuarine macroinfaunal communities in patchy habitats

Abstract Estuarine benthic macroinfauna have aggregated, patchy distributions, making accurate community measurements dependent upon sampling scales. The purpose of this study is to determine the appropriate core sizes and sampling effort needed to characterize benthic infaunal communities in Corpus Christi Bay, Texas, USA. Macroinfauna were sampled with small (6.7 cm) and large cores (15 cm) at two sites to determine if different sampling sizes characterized different spatial scales. Vertical distribution was sampled from 0 to 20 cm (0–3 cm, 3–10 cm, and 10–20 cm) to determine appropriate sampling depths. Eleven replicates of small cores were collected to assess species accumulation with area sampled. The log‐area to log‐diversity relationship was used to determine which core size and number of replicates accurately estimated abundance, biomass, and diversity of macrofauna. Seven replicates of small cores captured 100% of species richness. In the same area sampled, small cores found 25% more species diversity than large cores in one station and 58% more in the other. Three to five replicates of small (6.7 cm) cores provided sufficient precision to estimate abundance, biomass, and diversity. In Corpus Christi Bay, small scale patch dynamics regulate community structure and sampling with three replicate small cores to a depth of 10 cm can accurately characterize the small‐scale patches.