Insights into community-based bioassessment of environmental quality status using microphytobenthos in estuarine intertidal ecosystems

Abstract

The feasibility of community-based bioassessment of environmental quality status was studied using microphytobenthos (MPB) in estuarine intertidal ecosystems. The sediment samples of MPB were collected monthly during a 1-year cycle (September 2006–August 2007) at four sampling stations in the Nakdong River Estuary, Korea. Environmental variables, such as salinity, radiation, grain size of sediment, Si(OH)4 (Si), nitrate (NO 3 – ), nitrite (NO 2 – ), ammonium (NH 4 + ) and phosphates (PO 4 3– ), were measured synchronously for comparison with biotic parameters. The statistical analyses were carried out for assessment the relationship between biotic and environmental parameters. The results showed that: (1) the MPB community structures were significant differences among four sampling stations; (2) spatial variation in the MPB communities were significantly correlated with environmental variables, especially the nutrient NH4 + in combination with salinity and grain size; (3) three species (Navicula lacustris, Pleurosigma anglulatum and Fragilaria sp. 1) were significantly correlated with nutrients and/or Si; and (4) the species richness and diversity were significantly correlated with the grain size. It is suggested that MPB communities may be used as a potentially robust bioindicator for assessing environmental quality status in estuarine intertidal ecosystems.