A pitfall of understanding planktonic protozoan community dynamics on sampling time intervals

Abstract

To determine a reasonable sampling interval for analyzing ciliate plankton dynamics, ciliate plankton samples were collected daily from Aug. 2008 to Oct. 2009 in Jangmok Bay of Geoje Island. Species composition and abundances were analyzed and environmental parameters (temperature and salinity) were also examined. According to the sampling time intervals of daily, weekly, biweekly, monthly, and seasonal samplings, the temporal patterns of ciliate abundance change were compared. The temporal pattern in daily interval was described detail change of the ciliate abundance. Abundance data collected in weekly interval was enough reflected in the daily result while those in monthly and seasonal intervals were distorted comparing with the daily pattern. In particular, daily observation is necessary for finding an ecological signal on the species level such as indicative species monitoring. It is suggested that data harvesting in the weekly interval is desirable to understand well the variation of ciliate abundances. Ciliate populations in Jangmok Bay were characterized by abrupt appearance and disappearances of many species, and such fluctuation impose important constraints upon designing sampling regimes.