Distribution Patterns of Meiofauna on Sandy Beaches of Sapelo Island, Georgia

Abstract

Substantial abundance and diversity of meiofaunal intertidal invertebrates have been evidenced along two adjacent sandy beaches of Sapelo Island, Georgia. Meiofauna are small benthic, nearly ubiquitous, animals. They consume microbes and detritus, and in turn, are a food source for juvenile fish and ghost shrimp. Significant taxa differences of meiofauna were found within a small geographic region. In June, 2012, sand samples were collected from low, middle and high intertidal zones, and in depth ranges of 0-5 cm and 6-10 cm during low tide. Meiofauna were chemically and mechanically separated from the sand substrate and stained with Rose Bengal to visualize. On Nanny Goat and Cabretta beaches, a total of 23 meiofaunal clades were identified; Nematode worms were abundant in all zones and depths. A compelling increase in overall meiofauna abundance was found on Cabretta Beach, with twice as many Nematodes and 31 fold more Sipuncula worms observed, in comparison to Nanny Goat Beach. Indicators such as sand grain size, slope of the beach and weathering processes, such as deposition and erosion, may provide evidence for this meiofaunal variation. Surveying meiofauna on Sapelo Island could provide future insight into understanding metazoan food webs, beach disturbances and ecological contamination.