Impact on Marine Species of New England Recreational Fishing Policies.

Abstract

Marenzelleria viridis dominated the benthos of the Quashnet River in both abundance and biomass. In the Childs River, Lumbricillus spp. and Neanthes virens were again the main contributors. Salinity appeared to be the primary factor controlling the distribution of the macroinfaunal species; but within any single salinity range, eutrophication seemed to be responsible for differences in the composition and abundance of macrofauna between estuaries. The abundance of oligochaetes and insect larvae and the occurrence of a large carnivore increased with nutrient loading, whereas the number and biomass of other typically resident species decreased. Most significantly, the ratio of polychaetes to oligochaetes was clearly lower in the Childs River (0.36) than in the Quashnet River (3.58). We contrasted the benthic assemblages within the heavily nutrient-loaded Childs River estuary to those of the more moderately loaded Quashnet River estuary by constructing plots of ranked species dominance (3). The biomass and abundance of each species were ranked from highest to lowest and plotted against the cumulative percent biomass or percent abundance (Fig. 1). Plots in which the k-dominance curve for biomass falls above the curve for abundance are indicative of communities in which the most abundant fauna are large, slower growing species. These communities are indicative of relatively unstressed conditions. Plots in which the curve for abundance falls above the curve for biomass represent communities in which the most abundant species are small and rapidly growing. These are more typical of disturbed or eutrophied communities (1). No large differences were apparent between the k-dominance curves of abundance and biomass in the upper portion of either estuary. In both the middle and lower portions of the estuaries, the evaluation suggests that Childs River, with its more urbanized watershed, is more impacted by nutrient loading than the Quashnet River. We acknowledge the MBL Associates Fellowship that supported Rafael Sarda during this work.