Why we care: Enhancing our ability to measure water chemistry with the best technology available is essential to understand and track where and how ocean acidification changes in marine ecosystems. The NOAA Pacific Marine Environmental Laboratory (PMEL) Carbon Group continuously augments, develops, and evaluates sensors on moorings to collect information about natural variability in inorganic carbon chemistry over daily to inter-annual cycles. This project will identify, develop, and implement the best technology to support the existing National Ocean Acidification Observing Network (NOA-ON) buoy network and increase coverage of ocean acidification time series observations.
What we are doing: The three main project activities include: 1) compile autonomous profile data at the Chába site and apply to biological exposure research; 2) test prototype total alkalinity (TA) sensors at the coral reef test-beds at Kaneohe Bay, Hawaii (CRIMP2 buoy) and Florida Keys (Cheeca Rocks buoy); and 3) continue development of a pCO2-DIC sensor based on the need to improve data return of two carbon parameters from the NOA-ON buoys. These sensors measure parts of the carbonate system, the ocean’s buffering system.
Benefits of our work: This project supports the main goals of the NOA-ON by quantifying temporal variability in the ocean carbon system and making these high-quality time series available to other scientists and the public. Specific benefits provided to stakeholders include: 1) improved understanding of the range of subsurface ocean acidification conditions in two U.S. coral systems; 2) improved understanding of annual, seasonal, and event-scale variability of subsurface ocean acidification conditions and the potential impact to marine organisms; and 3) improved access to high-quality, high-frequency subsurface data to inform biological research and validation of ocean biogeochemical models and coastal forecasts.
Acidification in brackish estuarine environments, such as the Chesapeake Bay, is intensified by coastal inputs such as runoff, atmospheric pollution and freshwater sources. The Chesapeake Bay is home to commercial shellfish hatcheries that supply seed that is sold to and planted in hundreds of shellfish farms within the Chesapeake. A great deal of research has been dedicated to understanding the impact of acidification on shellfish, and has shown even greater impacts to shellfish growth and survival in lower salinity and nutrient-rich environments. The shellfish industry relies on consistent hatchery production to sustain and expand operations that could greatly benefit from regional OA forecasts and metrics. This project will synthesize recent CO2 system observations with long-term water quality parameters and combine observations an existing baywide, high-resolution 3D model. The proposed research will develop forecasts of acidification and develop acidification metrics tailored to support decision-making needs of commercial shellfish hatchery and nursery operators.
Among the NOAA designated Large Marine Ecosystems, the Gulf of Mexico (GOM) remains poorly understood in terms of its current OA conditions, despite its ecological and economic significance. In the northwestern GOM (nwGOM), decadal acidification has been observed in the shelf-slope region, with metabolic production of CO2 contributing to a larger fraction of CO2 accumulation than uptake of anthropogenic CO2, and the observed rate of acidification is significantly greater than that in other tropical and subtropical areas. Unfortunately, whether the observed OA in this region represents a short-term phenomenon or a long-term trend is unknown. It is hypothesized that increasing atmospheric CO2, increasing terrestrial nutrient export due to an enhanced hydrological cycle, and enhanced upwelling due to climate change will cause the continental shelf-slope region in the nwGOM to acidify faster than other tropical and
subtropical seas. In order to test this hypothesis wave gliders, in -stiu sensor along withe underway measurements from research vessels will measure carbonated chemistry in in surface and shallow waters. Modeling will be used tp integrate the chemical signals into the models to hindcast/predict spatia; and temporal variation of the OA signal for the the optimization of monitoring design and implementation.
The U.S. Northeast Shelf Large Marine Ecosystem, supports some of the nation’s most economically valuable coastal fisheries, yet most of this revenue comes from shellfish that are sensitive to ocean acidification (OA). Furthermore, the weakly buffered northern region of this area is expected to have greater susceptibility to OA. Existing OA observations in the NES do not sample at the time, space, and depth scales needed to capture the physical, biological, and chemical processes occurring in this dynamic coastal shelf region. Specific to inorganic carbon and OA, the data available in the region has not been leveraged to conduct a comprehensive regional-scale analysis that would increase the ability to understand and model seasonal-scale, spatial-scale, and subsurface carbonate chemistry dynamics, variability, and drivers in the NES. This project optimizes the NES OA observation network encompassing the Mid-Atlantic and Gulf of Maine regions by adding seasonal deployments of underwater gliders equipped with transformative, newly developed and tested deep ISFET-based pH sensors and additional sensors (measuring temperature, salinity for total alkalinity and aragonite saturation [ΩArag] estimation, oxygen, and chlorophyll), optimizing existing regional sampling to enhance carbonate chemistry measurements in several key locations, and compiling and integrating existing OA assets. The researchers will apply these data to an existing NES ocean ecosystem/biogeochemical (BGC) model that resolves carbonate chemistry and its variability.