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(38-14) Optimizing study design and quantifying sediment impacts in a deep-sea environment. Maxon, Cynda*,1, Tait, Russell2, Newton, Frederick1, 1 Battelle Memorial Institute, Carlsbad, California2 ExxonMobil Production Company, Houston, Texas ABSTRACT- Physical, chemical and biological sediment data comprise the monitoring triad typically used to gauge impacts from offshore oil exploration and production activities, where benthic communities are potentially at risk from associated hydrocarbon and metal contaminants. Adverse biological effects from chemical contaminants are difficult however to determine, due to system variability and confounding factors such as depth, sediment grain size, food availability, recruitment and predation. This study presents the results of a tiered analytical approach used to optimize sampling design, identify key biological variables and set threshold effect levels appropriate to quantify post-drilling impacts to the benthic environment. The approach, which is applicable to other investigations concerned with spatial and temporal variability, uses multivariate statistics and predictive models to examine sediment data collected over 80-800 m depth from a 600 km2 area in the south Caspian Sea. Key words: deep-sea sediment impacts, multivariate statistics, hydrocarbons, benthic community |
