Physiological measurements on Nucula tenuis and on isolated gills of Mytilus edulis and Carcinus maenas

Abstract

In experimental exposures carried out for the GEEP Workshop, measurements on the deposit-feeding bivalve mollusc Nucula tenuis indicated an increase in protein catabolism in the medium and low-dose mesocosm basins, registered as increased nitrogen quotients; the implications for pollutant effect assessment are unclear, but further research on deposit-feeding species is warranted. For Mytilus edulis, gill oxygen uptake rates did not differ between samples, in either the workshop field or mesocosm studies; oxygen consumption rates of isolated gills correlated with consumption rates for the whole organism, but showed no relationship with clearance rate. Rates of oxygen consumption by isolated gills of Carcinus maenas revealed effects of pollution at one of the field sites, but were unresponsive to contaminant levels within the mesocosm. In these experiments, measures of physiological function in isolated tissues were relatively insensitive to pollutant stress.