Operation and integration of a commercially available nitrate sensor in Gulf of Mexico estuarine monitoring programs

• Published in: Environmental technology & innovation 2024-08, Vol.35, p.103676, Article 103676
• Main Authors: Raabe, Jennifer M., Kurtay, Gulce, Fontenot, Amanda, Greene, Sierra, Martignette, A.J., Milbrandt, Eric C., Roberts, Brian J., Stauffer, Beth A.
• Format: Article
• Language: English
• Subjects: High frequency; Observing systems; Pollution; Runoff; Water quality
• ISSN: 2352-1864; 2352-1864
• DOI: 10.1016/j.eti.2024.103676

Many coastal and estuarine environments suffering from eutrophication, hypoxia, and harmful algal blooms need continuous nutrient monitoring to better understand the drivers of these events and evaluate progress towards water quality improvement targets. Many dissolved-nutrient sensors are now commercially available with several being evaluated in terms of relative accuracy, precision, limits of detection, and measurement range. There remains a need to test integration of these sensors into existing water quality monitoring programs. This study tested the operational status and integration of a commercial, in situ chemical analyzer for nitrate in two existing monitoring programs in Louisiana and Florida as a pilot study for the development of a nutrient monitoring program across Gulf of Mexico estuaries. Both sites deployed the same sensor, but with slightly altered equipment configurations which resulted in large differences in the duration of data, with 161 (out of 353) days of data collected in Florida compared to 26 (out of 228) days of data in Louisiana. Sensors were also exposed to different nitrate regimes in Florida (mean = 8.94 µM; max = 23.9 µM) versus Louisiana (mean = 2.66 µM; max = 12.9 µM), and site-specific relationships between sensor and reference data were apparent. Also highlighted are the needs to address integrating new sensors into existing monitoring infrastructure including full interoperability with non-proprietary datalogger systems and ongoing needs for more site-specific calibrations and post-hoc corrections. Addressing these needs will help ensure successful integration into existing monitoring infrastructure and availability of continuous nutrient data. [Display omitted] •Nutrient sensor deployment durations varied with site and sensor configuration.•Interoperability with commercial dataloggers is essential for sensor integration.•Matching reference sample and sensor intake filtration sizes vital for data quality.