The USGS Northeast Stream Quality Assessment, 2016

Stream water sampling. Kelly Rausch, USGS.

In 2016, the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) studied stream quality in the northeastern United States. The Northeast Stream Quality Assessment (NESQA) measures the water-quality stressors that affect aquatic life and how they relate to biological communities.

• Focus: the effects of urbanization and agriculture, in all or parts of eight states — Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont.
• Why: to tell the public and policymakers which factors matter most for stream health, and so how streams might be protected.
• The series: the fourth regional study of its kind, after the Midwest (2013), Southeast (2014) and Pacific Northwest (2015).

Objectives

1. Assess stream quality across the region: nutrients, contaminants, toxicity, sediment, flow, habitat and biological communities.
2. Weigh the influence of chemical and physical stressors on stream life.
3. Relate watershed characteristics, natural and human, to the stressors and communities.
4. Build models and tools to predict stressors and ecological conditions in wadeable streams across the region.

Design

Ninety-five sites were sampled for up to 9 weeks in June, July and early August 2016, ending with an ecological survey of habitat, algae, benthic invertebrates and fish at every site.

The study builds on 2014 sampling in the Northeastern Highlands of sites where streamflow has been altered, so the data should span wide ranges of many stressors.

What was measured

• Ecological condition: algae, macroinvertebrates and fish sampled, and habitat surveyed, once per site in August 2016, along a 150-meter reach.
• Water: weekly samples — for 9 weeks at urban and farm sites, 4 weeks at forested ones — for nutrients, suspended sediment, major ions, pesticides and their breakdown products; some weeks also for mercury, pharmaceuticals and wastewater indicators.
• Passive samplers (POCIS): left at all 95 sites for about 6 weeks to gauge chronic exposure to dissolved pesticides, pharmaceuticals and wastewater compounds.
• Streambed sediment: from all 95 sites, for trace elements, radionuclides, pesticides, PAHs, halogenated compounds such as DDT, wastewater compounds and hormones — sediment holds different contaminants than water and can feed them to organisms.
• Sediment sources: time-integrating suspended-sediment samplers at about 14 sites, analyzed for radionuclides and trace elements.
• Toxicity: sediment from about half the sites tested on amphipods (Hyalella azteca, 28-day exposures), midge larvae (Chironomus dilutus, 10-day) and freshwater mussels (Lampsilis siliquoidea, 28-day) for effects on survival and growth — many stream animals are sensitive to some current-use insecticides and to PAHs.
• Continuous monitoring: water level and temperature at all 95 sites; full water-quality monitors, including dissolved oxygen and nitrate, at 5.
• Daily pesticides: automated samplers at seven sites, analyzed by the EPA's Office of Pesticide Programs, to capture short-term acute exposures.
• Methane: part of the region overlies the Marcellus Shale, where natural gas wells are being developed quickly; a reconnaissance of methane in streams in Pennsylvania and south-central New York was planned.
• Algal toxins: a July 2016 survey of microcystin, a toxin made by some cyanobacteria, little studied in small streams.
• Mercury in fish: fish from all 95 sites analyzed for total mercury, and some for mercury isotopes, which can point to its sources.

Brook trout (Salvelinus fontinalis). Barry Baldigo, USGS.

Stream water sampling. Kelly Rausch, USGS.

Sources

Based on The Northeast Stream Quality Assessment, by Peter C. Van Metre, Karen Riva-Murray and James F. Coles, USGS Fact Sheet 2016–3021, U.S. Geological Survey (DOI); a work of the United States government in the public domain. The photographs come from the fact sheet's PDF; its study-area map, drawn on a licensed commercial base, is left out. More: USGS National Water-Quality Assessment.