Barry Hargrave (Canada)
ABSTRACT
A survey of benthic variables at cage and reference sites was used to identify variables useful for cost effective monitoring of benthic conditions. Benthic gas fluxes, sulfide and Eh were the most significantly different variables between reference and cage sites. Surface sediment Eh and organic carbon combined to calculate a benthic enrichment index (BEI) which was inversely correlated with organic carbon sedimentation. Sedimentation >1 g-C m-2 d-1 represents a threshold of sustainable benthic oxidation. Regression analysis was used to calculate carbon sedimentation from BEI which can be compared to sediment respiration. Imbalance indicates over or undersupply relative to potential loss through benthic respiration.