Hemocyanin concentrations in marine crustaceans as a function of environmental conditions

Abstract

A variety of physiological and biochemical measures have been proposed in the literature as indicators of environmental quality. Here we report studies which were designed to determine if hemolymph hemocyanin concentrations in blue crabs Callinectes sapidus could be correlated with environmental water quality. To this end hemocyanin concentrations were measured in hemolymph of blue crabs collected from North Carolina, Florida, and Texas, USA. Blue crabs from isolated estuarine systems in eastern North Carolina (i.e. Albemarle/Pamlico Sound area) had significantly lower concentrations of hemocyanin in their hemolymph than crabs from reference areas (i.e. Core and Currituck Sounds). These lower concentrations could be correlated with reduced dissolved oxygen and chronic hypoxia, but not with any known sources of anthropogenic contamination. Among crabs from Tampa Bay (Florida) and the Houston (Texas) Ship Channel there was a negative correlation between the degree of industrialization and organic contaminants in the digestive gland and sediments and hemocyanin concentration. In the Houston Ship Channel decreased dissolved oxygen confounded the possible correlation with contaminants. In all areas sampled, lower concentrations of hemocyanin were not correlated with either the apparent health or sex of the crabs or with salinity.