(PH248) Integrating and communicating results of large scale sediment quality assessment studies.
Hameedi, J.1, 1 National Oceanic and Atmospheric Administration, Silver Spring, Maryland, U.S.A.
ABSTRACT- Both the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Environmental Protection Agency have conducted broad-scale, regional assessments of sediment toxicity in the U.S. coastal waters and estuaries in response to federal mandates and other requirements. Both agencies have used the Sediment Quality Triad (SQT) approach, which is based on synoptic measures of contamination, toxicity, and faunal distribution and offers a weight of evidence to infer the nature and extent of pollution in a given area. A review of cumulative, natiowide data suggests that, based on the incidence of amphipod mortality, sediment toxicity is spatially quite limited although it varies considerably among the areas studied. The spatial extent of sediment toxicity is much greater when based on the results of sub-lethal toxicity tests and testing on more sensitive organisms. Typically, the resulting data from SQT studies are presented as listings, tabular matrices, pie diagrams, or as outcomes of multivariate statistical analyses. Quite often such presentations lack integration or need an expression that is readily interpretable by resource managers and the public. This paper introduces an index to present results of the triad by developing a scoring system, presenting the results on a tri-axial plot, and estimating area of the triangle to quantify the overall condition in the study area or a particular sampling stratum. The index can be used to compare environmental conditions in specified geographical areas and gauge the extent and severity of contamination over time. A case example is presented with data from Galveston Bay that was studied as part of NOAA's National Status and Trends Program.
Key words: Index, Contamination, Sediment Quality Triad