W9 AM Biomonitoring
Wednesday, 16 November 2005: 8:00 AM - 11:40 AM in 339-340

(KEY-1117-555468) Grass shrimp populations as indicators of sediment contamination and water quality in South Carolina estuaries.

Key, P¹, West, J¹, Riekirk, G², Pennington, P¹, Fulton, M¹, Scott, G¹, ¹ NOAA/NOS/NCCOS/CCEHBR, Charelston, SC² SCDNR, Charleston, SC

ABSTRACT- Coastal systems in the US are ecologically important aquatic environments due to their diversity and productivity. Coastal areas also serve as sinks for pollutants transported via runoff and atmospheric deposition. Grass shrimp, a common inhabitant of US East and Gulf coast estuaries, have been utilized in past research as a bioindicator of the effect that human activity can have on estuaries. The goal of this study was to determine if estimates of adult grass shrimp populations in tidal creeks could be correlated with water quality and sediment contamination measured from the same creek. In August of each year from 1999 to the present, approxmately 30 creeks along the South Carolina coast were sampled each year by dip net for estimates of grass shrimp density. This was part of the broader South Carolina Estuarine and Coastal Assessment Program (SCECAP). Water quality parameters and sediment contaminant levels were also measured in the creeks. SCECAP assigned an integrated habitat quality score, based on an integrated assessment of water and sediment quality and a benthic index of biotic integrity, to each sampled creek. In data from the 2001 sample year, out of 27 creeks assessed , 20 scored good, 6 scored fair and 1 scored poor. From this 2001 preliminary data, grass shrimp populations showed no correlation between density and the score. Also for this 2001 data set, stepwise regression analysis was used to investigate the relationship between site-specific physico-chemical factors and grass shrimp population densities. Density was found to be negatively correlated with pH and arsenic levels and positively correlated with dissolved oxygen and nickel levels. The other sample years from 1999 to the present, along with other population parameters, were also investigated and will be reported.

Key words: grass shrimp, bioindicator, metals, density