Differences in benthic invertebrate assemblages in two estuaries of Waquoit Bay receiving disparate nutrient loads

We evaluated the effects of nutrient loading on benthic communities by measuring the abundance and composition of macroinfaunal assemblages inhabiting similar habitats within two Waquoit Bay estuaries subject to different rates of nutrient loading. On the basis of water recharge rates and dissolved inorganic nitrogen concentrations in groundwater at the shore, we estimated that each year about 8500 kg of nitrogen enter the Childs River estuary and roughly 3500 kg enter the Quashnet River. The intensity of nutrient loading to these estuaries differs primarily because of differences in the density of houses and septic systems within their surrounding watersheds.