Water Quality

The silhouette of two divers holding a line with a buoy in blue water, with the shadow of a boat above. The outline of square instruments is visible on the sandy seafloor below.
Divers attach a subsurface buoy to water quality sampling instruments. Photo: Emma Hickerson/NOAAA

Conservation Issue

Regional and local stressors, sources, and inputs affect water quality in Flower Garden Banks National Marine Sanctuary (FGBNMS). Monitoring, preserving, and preparing for changes in water quality at all scales is essential for the overall sustainability of the habitats, fish, and other wildlife within FGBNMS.

Description

Since the 1970s, researchers have been recording water temperatures to better understand trends across the reefs of FGBNMS. In 1989, FGBNMS began the long-term monitoring program at East and West Flower Garden Banks, in partnership with the Bureau of Ocean Energy Management, and in 2015, the program expanded to include Stetson Bank. Since then, FGBNMS has been monitoring selected water quality parameters at the three banks using a combination of remote depth sensors as well as profiling and sampling instrumentation. FGBNMS has also partnered with universities and non-profit organizations to expand water quality monitoring to include ocean acidification and microplastic sampling.

Despite having one of the longest continuous datasets in the wider National Marine Sanctuary System, much is still unknown about FGBNMS waters. Specific water quality concerns that require further study include rising seawater temperatures, sea level rise, ocean acidification, decreased dissolved oxygen levels, and changing weather and storms. Pollutants from a variety of sources, including those from land or discharges in the open ocean, may also impact water quality. With the addition of 14 reefs and banks to FGBNMS in 2021, there is a pressing need to expand monitoring efforts to these remote areas. Understanding changes in water quality in FGBNMS and surrounding waters is key to protecting the site's biological resources.

Data and Analysis Needs

  1. Repeated measures of water quality parameters at various locations within the expanded sanctuary
  2. Monitoring of bacteria in the water column that pose human health risks or are derived from human activities and have the potential to impact reef health
  3. Nutrient and contaminant loadings from regional sources, such as Louisiana and Texas river discharges and storm runoff, into the waters surrounding FGBNMS
  4. Nutrient and contaminant loading that may occur from ballast water discharge into the waters surrounding FGBNMS
  5. Evaluation of the effectiveness of current standards for protecting water quality, coral reefs, and other marine resources at FGBNMS
  6. Appropriate water quality parameters and thresholds for coral reef health
  7. The relationships between nutrient loading and climate stressors, such as ocean acidification and warming, and their impacts on coral reefs
  8. The resistance and resilience of FGBNMS organisms to changes in water quality compared to those in other reef locations
  9. Methods to enhance the effectiveness of outreach programs and messaging aimed at promoting water quality protection among residents in the Gulf of Mexico region
  10. The effects of water quality (e.g., temperature, dissolved oxygen, nutrients) on the movement of mobile species
  11. Shifts in environmental DNA (eDNA) composition in sanctuary waters associated with changes in water quality
  12. Information on the triggers for low dissolved oxygen conditions at FGBNMS

Potential Products

  • An FGBNMS-specific nutrient loading model that includes factors such as upstream agricultural runoff, urban effluent discharge, and atmospheric deposition
  • Updated and more comprehensively equipped water quality monitoring stations that provide near real-time water quality information, capture episodic events, and detect regional inputs effectively
  • A water quality monitoring plan that includes baseline measurements and sampling protocols for all 17 banks, including expanded testing for heavy metals and minor nutrients
  • A water quality model with predictive forecasting to evaluate how episodic increases in freshwater flow, including nitrogen loading from river discharge, may impact FGBNMS habitats
  • Strike team response protocols for assessing the effects of pulses in poor water quality (e.g., floodwaters moving offshore following extreme storms)
  • Buoys throughout FGBNMS that collect and transmit water quality data in near real-time
  • Regular updates on evolving water quality metrics and thresholds developed across the Gulf of Mexico to ensure FGBNMS sampling aligns with best practices
  • A community science program that enables fishing vessels and divers to contribute meaningful water quality data from FGBNMS

Supplementary Information

For more information about this assessment, contact flowergarden@noaa.gov.