Suzanne M. Lussier

Development of a reference coastal wetland set in Southern New England (USA)

Various measures of plants, soils, and invertebrates were described for a reference set of tidal coastal wetlands in Southern New England in order to provide a framework for assessing the condition of other similar wetlands in the region. The condition of the ten coastal wetlands with similar hydrology and geomorphology were ranked from least altered to highly altered using a combination of statistical methods and best professional judgment. Variables of plants, soils, and invertebrates were examined separately using principal component analysis to reduce the multidimensional variables to principal component scores. The first principal component scores of each set of variables (i.e., plants, soil, invertebrates) significantly (p < 0.05) correlated with both residential land use and watershed nitrogen (N) loads. Using cumulative frequency diagrams, the first principal component scores of each plant, soil, and invertebrate data set were plotted, and natural breaks and best professional judgment were used to rank the first principal component scores among the sites. We weighted all three ranked components equally and calculated an overall salt marsh condition index by summing the three ranks and then transforming the index to a 0–1 scale. The overall salt marsh condition index for the reference coastal wetland set significantly correlated with the residential land use (R = − 0.87, p = 0.001) and watershed N loads (R = − 0.86, p = 0.001). Overall, condition deteriorated in salt marshes and their associated discharge streams when subjected to increasing watershed residential land use and N loads.

Influence of salinity and organic carbon on the chronic toxicity of silver to mysids (Americamysis bahia) and silversides (Menidia beryllina)

Tests were conducted with mysids (Americamysis bahia) and silversides (Menidia beryllina) to evaluate the influence of salinity and organic carbon on the chronic toxicity of silver. During 7- and 28-d tests conducted at 10, 20, and 30% per hundred salinity, higher concentrations of dissolved silver generally were required to cause a chronic effect as the salinity of the seawater was increased. The 28-d mysid and silverside 20%-effective concentration values (expressed as dissolved silver) ranged from 3.9 to 60 and from 38 to 170 microg/L, respectively, over the salinity range. This pattern was not observed when the same test results were evaluated against the concentrations of free ionic silver (measured directly during toxicity tests), as predicted by the free-ion activity model. Increasing the concentration of dissolved organic carbon from 1 mg/L to the apparent maximum achievable concentration of 6 mg/L in seawater caused a slight decrease in chronic toxicity to silversides but had no effect on the chronic toxicity to mysids. The possible additive toxicity of silver in both food and water also was investigated. Even at the maximum achievable foodborne concentration, the chronic toxicity of silver added to the water was not affected when silver was also added to the food, based on the most sensitive endpoint (growth). However, although fecundity was unaffected at all five tested concentrations during the test with silver in water only, it was significantly reduced at the two highest waterborne silver concentrations (12 and 24 microg/L) during the test with silver dosed into food and water.

Strategies for Protecting and Restoring Rhode Island's Watersheds on Multiple Scales

The Clean Water Act has traditionally preserved the quality and quantity of a regions water by focusing resources on areas with known or anticipated problems. USEPA Region 1 is taking the supplemental, longer-range approach of protecting areas of New England where natural resources are still healthy. As part of Region 1 s “New England Resource Protection” approach, stakeholders participate in an open process that identifies healthy ecosystems and characterizes how well they support aquatic life and human health. Since the concerns of stakeholders are usually local, the process also displays areas of nonattainment within individual watersheds and determines their likely causes. One of the most powerful ways to display these types of information on multiple scales is to use a geographic information system (GIS). The case of phosphorus in southern Rhode Islands Tucker Pond illustrates how a GIS can help integrate concerns from the public, data from Clean Water Act monitoring, and information from the New England Resource Protection Project to identify types of environmental assessment questions on scales ranging from states to subwatersheds. By involving the public at all stages of the process and better informing them about their watersheds, this new approach makes them better stewards of their environment.