Water quality of selected wetland streams in central and eastern Massachusetts, 1988-89

Abstract

Water quality, and basin, stream, and wetland characteristics are described for selected wetland streams of central and eastern Massachusetts. Water-quality data from 22 wetland reaches on 15 streams were analyzed using boxplots for selected water-quality and basin, stream, and wetland characteristics. Nonparametric statistical techniques were used to check for significant differences between upstream and downstream concentrations and loads. Stream nutrient and dissolved-oxygen conditions varied in the selected wetland-stream reaches. For the 22 wetland stream reaches, properties and constituents that increased in more than 65 percent of the stream reaches included discharge, specific conductance, temperature, turbidity, sodium, dissolved and total ammonia plus organic nitrogen, and iron. Easily measured characteristics of wetland streams were not reliable indicators of water quality for the existing data set. The lack of consistent changes in water quality between the upstream and downstream sampling sites suggests that the existing data for the selected wetland reaches cannot be used to reliably determine the effect of wetlands on stream-water quality. A carefully designed data-collection program is needed for the successful evaluation of dissolved oxygen and nutrients in wetland reaches. Components of a data-collection program would include careful site selection, proper timing and intensity of sampling throughout the year, and additional water-quality data needed for dissolved-oxygen and nutrient modeling. METHODS This section describes the study design and the evaluation of available data from Socolow (1994), along with the methods used for the measurement of basin, stream, and wetland characteristics, for the measurement of stream-water quality, and for data analysis.