Refining Techniques for High-Frequency Monitoring of Chlorophyll in the NERRS

  • Sampling in GTM NERR, FL. (Credit: Shannon Dunnigan)

    Sampling in GTM NERR, FL. (Credit: Shannon Dunnigan)

  • Sampling in He'eia NERR, HI.

    Sampling in He'eia NERR, HI.

  • Lab work at Mission Aransas NERR, TX.

    Lab work at Mission Aransas NERR, TX.

  • Filtering samples for chlorophyll. (Credit: Shannon Dunnigan)

    Filtering samples for chlorophyll. (Credit: Shannon Dunnigan)

  • Sampling in Old Woman Creek NERR, OH.

    Sampling in Old Woman Creek NERR, OH.

  • Sampling in Old Woman Creek NERR, OH.

    Sampling in Old Woman Creek NERR, OH.

  • Plankton cultures, Mission-Aransas NERR, TX.

    Plankton cultures, Mission-Aransas NERR, TX.

Many estuaries across the country experience nutrient pollution and algal blooms, which degrade water quality for people and other aquatic life. Careful tracking of chlorophyll a concentrations - a proxy for phytoplankton biomass - can help managers understand the patterns and drivers of algal blooms and eutrophication in their estuary. Currently, the National Estuarine Research Reserve System’s long-term monitoring program measures chlorophyll by collecting and filtering monthly water samples and extracting algal pigments from the filter in a laboratory. However, monthly measurements are not sufficient for tracking plankton dynamics, which fluctuate hourly. With a national representation of 13 reserves, this project will advance the use of new sensor technology that can measure chlorophyll every 15-minutes, with the goal of catalyzing the Reserve’s System-Wide Monitoring Program into the most comprehensive algal bloom monitoring program in the nation.

This project will develop, test and share standardized protocols for using new sensors - YSI EXO Total Algae fluorometric sensors - mounted on existing monitoring stations. Although there will be many applications for the data, interpreting and connecting the new measurements with long-term datasets is not straightforward. This project is led by research staff from 13 reserves, all of whom plan to use the tools and information generated. They will work collaboratively to: 1) assess the performance of new sensors by comparing field and laboratory sensor measurements with extracted chlorophyll concentrations; 2) identify sources of sensor interferences and develop standardized correction protocols for the new data streams; and 3) create and share tested protocols and recommendations for the Reserve System.

Project References