IMPLICATIONS FOR MONITORING - STUDY DESIGNS AND INTERPRETATION OF RESULTS

A Sediment Quality Triad approach was used to integrate concurrently o btained toxicological, sediment contaminant, and benthic ecological da ta from GOOMEX in a test of coherence of responses. The biological com munity responded to contaminants by increases in the ratio of ''the mo re tolerant taxon'' to ''the more sensitive taxon'': the nematode to h arpacticoid copepod ratio for meiofauna and the polychaete to amphipod ratio for macrofauna. Meiofaunal total abundance declined near platfo rms whereas macrofaunal total abundance increased - probably because o f organic enrichment near platforms. A second approach used small-scal e spatial heterogeneity of response as evidence of impact. Cd, Ba, Che mPC1 (first principal component of contaminant information), and the n ematode to harpacticoid ratio had significant heterogeneity of varianc e among distances from platform, with higher variances near platforms. The pattern for Cd and ChemPC1 suggests that the impact may extend ou t to 200 m. We argue that differing objectives which are often demande d of the same study are often in conflict (e.g., generalization about environmental impact of similar platforms has different design require ments than description of spatial pattern of impact around each platfo rm). Therefore, requiring that a study accomplish both objectives lead s to compromises and a suboptimal design for both.