PARENT SESSION
Poster Session # 17: Aquatic Systems.

Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Biomonitoring in New Jersey blackwater streams: recalibrating an invertebrate bioassay.

Cromartie, William^*,1, Gliddon, Jason¹, ¹ Richard Stockton College, Pomona, NJ, USA

ABSTRACT- In 2001, the New Jersey Department of Environmental Protection (NJDEP), using the Ambient Biomonitoring Network (AMNET) protocol for invertebrate bioassay, designated several streams in the NJ Pine Barrens impaired water quality. These designations conflicted with assessments carried out by the NJ Pinelands Commission, using fishes, macrophytes, pH, specific conductance, and percent developed land as criteria. In 2002, NJDEP changed all sites in the Pine Barrens listed as impaired based on biological sampling to insufficient scientific information. We have been working with the NJDEP Great Egg Harbor River (GEHR) Watershed Management Area project, the County of Atlantic and the Pinelands Commission to eliminate conflicts between AMNET and other predictors of water quality. We analyzed existing water quality and biotic data and developed GIS coverages, showing percent developed land in each sub-watershed. From these data, we developed a conceptual model of water quality in the GEHR basin. We selected sub-watersheds representative of conditions in the GEHR for preliminary study, sampled macroinvertebrates from gravel, mud and woody debris and measured pH and specific conductance. Invertebrates were identified to genus or family level. Multivariate analyses were used to determine relationships between invertebrate samples and other indicators. Invertebrate assemblages of the GEHR resemble those in blackwater rivers further south on the coastal plain, which helps explain why NJ AMNET criteria, developed for cobble-bottomed trout streams, work poorly. Strong correlations exist among the environmental variables, with percentage of developed land the best predictor. Invertebrate fauna is clearly affected by these variables. In streams with impaired water quality, species not found in pristine Pine Barrens streams increase. It appears that the macroinvertebrate fauna on woody debris in the streams is the best target for biological sampling. By studying this assemblage intensively, we hope to develop biological indices that can predict water quality change in the Pine Barrens.

Key words: blackwater stream, pine barren, biomonitoring, macroinvertebrate