Seasonal and three-year variability of meiobenthic nematode populations at two estuarine sites

Abstract

Three yr of continuous sampling of nematode species at 2 South Carolina estuarine sites (1 sand, 1 mud) indicate different species assemblages, abundance and seasonal patterns. Year-to-year variability was not great and was similar at both sites. The mud species were distinctly seasonal; the sand community lacked distinct seasonality. Juvenile fish predation probably controlled the seasonal population changes at the mud site, whereas at the sand site the lack of seasonality is thought to b e due to an active hydrodynamic regime which maintained the fauna at a relatively constant abundance. While 98 species were identified from the mud and 123 from the sand, only 6 in mud and 5 in sand were h g h enough in relative abundance to each conlpnse 3 O/ O or more of the total nematodes. These 11 species are chscussed in detall. Correlation of nematode species abundance (and their life stages, e.g. female, male, luvenile) with physical (temperature, salinity, Redox depth) and biological factors (diatom, bacteria abundance) were uninformative. There were no more significant correlahons than expected by chance. Neither a gravid female nor a juvenile maximum preceded the abundance maximum of any species suggesting that either the generations were overlapping and/or the nematodes had a continuous or protracted reproductive activity.