Assessment of estuarine water quality at Cape Hatteras and Cape Lookout National Seashores: 2015 data summary
Wright W and Thorsdatter W . 2016. Assessment of estuarine water quality at Cape Hatteras and Cape Lookout National Seashores: 2015 data summary. Natural Resource Data Series. NPS/SECN/NRDS—2016/1056. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/2235357
In July 2015 the Southeast Coast Network conducted an assessment of water quality in the vicinity of Cape Hatteras and Cape Lookout National Seashores as part of the National Park Service Vital Signs Monitoring Program. Monitoring was conducted following methods developed by the Environmental Protection Agency (EPA) as part of the National Coastal Assessment Program (EPA 2009). Laboratory analysis measured chlorophyll a and total and dissolved concentrations of nitrogen and phosphorous. Field measurements included water temperature, pH, dissolved oxygen, and salinity. Water clarity, which requires a Secchi depth measurement, was calculated when possible. Because waters were often too shallow to effectively obtain an accurate Secchi depth measurement, turbidity measurements are also presented. All measured parameters were rated as good, fair, or poor based on thresholds set by the EPA (2012). • Water clarity was not calculated at all sites due to the shallow depth of the seashore waters. Turbidity measurements ranged from 2.7 to 10.9 Formazin Nephelometric Units (FNU), and are good according to North Carolina state standards.. • Chlorophyll a concentrations were rated good at 24 sites (80% ). Six sites (20%) sampled in 2015 were rated fair. • Dissolved nutrient concentrations were good across the assessed area with dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) concentrations rated good at all 30 sites. • Dissolved oxygen levels were rated good at 97% of sites (29 of 30 sites) and fair at 3% (one site). • A water-quality condition summary index was calculated for each site sampled in Cape Hatteras and Cape Lookout National Seashores based on the categorical assessments of chlorophyll a, DIN and DIP concentrations, and dissolved oxygen. This summary index indicated good water-quality conditions at 93% of sites (28 of 30) and fair conditions at two sites (7%). • Although water-quality conditions were rated as good at most sites, two sites near Manteo exibited fair but degrading conditions, with elevated total nitrogen, and chlorophyll a concentrations, and low water-clarity conditions.
- Type
- Published Report
- Authors
- Wright, Wendy; Thorsdatter, Wendy
- Date of Issue
- 2016-09
- Publisher
- National Park Service
- DOI
- 10.36967/2235357
- Units
- CAHA , CALO , NRSS , SECN
- Keywords
- CALO; CAHA, Marine Water Quality Monitoring; coastal assessment; synoptic monitoring