Ocean Acidification on a Crossroad: Enhanced Respiration, Upwelling, Increasing Atmospheric CO2, and their interactions in the northwestern Gulf of Mexico
Why we care In the coastal ocean, local drivers such as nutrient input and physical oceanographic changes impact the magnitude of short-term variations and long-term trends in ocean acidification. The Gulf of Mexico’s coral reefs and banks are ecologically sensitive to changing ocean chemistry. Decadal acidification has been observed in the Northwestern Gulf of Mexico, linked more strongly to biological production of carbon dioxide than uptake of human-emitted carbon dioxide. Whether the observed acidification in this region represents a short-term phenomenon or a long-term trend is unknown. This project maintains critical ocean acidification monitoring in a region with impacted habitats and species.
What we are doing This project will test the hypothesis that enhanced atmospheric carbon dioxide, nutrient input, and upwelling will cause the continental shelf-slope region in the Northwestern Gulf of Mexico to acidify faster than other tropical and subtropical seas. The research team will incorporate observations from new large-scale surveys into oceanographic and statistical models that predict variation in ocean acidification over space and time.
Benefits of our work The outcomes of this project will meet the long-term goal of optimizing ocean acidification monitoring in the Northwestern Gulf of Mexico and will document methodology that can be used in similar efforts in the future. This project will examine an area in the poorly understood Gulf of Mexico Large Marine Ecosystem, produce the first ever high-resolution dataset in surface and subsurface waters, and direct the future deployment of in-situ monitoring devices in this ecologically and economically important region.
Why we care Long-term observations of carbonate chemistry at U.S.-affiliated coral reef sites are critical to understanding the impact of ocean acidification (OA) on coral ecosystems over time. The NOAA Coral Reef Conservation Program (CRCP) brings together scientists across NOAA to conduct sustained coastal ocean observations of biological climate and socioeconomic indicators in 10 priority U.S. coral reef areas.
What we are doing This project will provide high-quality carbonate chemistry data at a newly established National Coral Reef Monitoring Plan (NCRMP) monitoring site in Fagatele Bay, American Samoa. Using an interdisciplinary approach, scientists will collect, process, analyze, and steward continuous ocean acidification data. Observations of the carbonate system, the ocean’s buffering system, will be collected via a Moored Autonomous pCO2 (MApCO2) buoy providing freely-available high-quality carbon dioxide data that can then be used by project collaborators and partners to further research.
Benefits of our work The outcomes generated from this monitoring project will advance our understanding of the carbon cycle of coral reefs in American Samoa and the impacts to coral ecosystems. Ocean acidification data will help elucidate the natural biogeochemical influences at reefs, and can be used to determine if the magnitude of acidification occurring in the open ocean is also occurring on coral reefs.
Why we care The Insular Pacific-Hawaiian Large Marine Ecosystem (IPH-LME) Complex provides critical benthic and oceanographic habitats for important fisheries and protected resources. A critical missing piece in assessing vulnerability in the Hawaiian Islands to ocean change is understanding the variability of ocean properties and ocean acidification in space and time. Coral reef managers are particularly challenged with sustaining the ecosystem functions and services under changing environmental and human impacts.
What we are doing This project takes a modeling approach to link the state of the ecosystem with societal outcomes to assess risk vulnerability in the IPH-LME. Researchers will combine state-of-the-art climate, regional, and coral reef ecosystem models with satellite assessments of ocean acidification. Results will provide robust projections of ocean acidification-related stress across the IPH-LME for the next 5 decades (2020-2070. Societal data will be collected through interviews, workshops, and community surveys to expand the number of relationships modeled. Vulnerability of the Hawaiian Islands to the projected ocean acidification-related stress will be evaluated using relationships between ecological and social state components. Resource managers will evaluate tradeoffs between different management practices and climate futures to determine which interventions would be most effective in supporting ecosystem integrity while enhancing societal wellbeing in the face of ocean acidification.
Benefits of our work Collaboration between scientists, managers, non-governmental organizations, and resource users will help ensure that socio-economic and biophysical processes are both considered when evaluating consequences of policy decisions and climate projections. This transdisciplinary approach provides opportunities to build relationships among the project stakeholders. This project directly supports the Hawai‘i Division of Aquatic Resources (DAR) in its efforts to develop vulnerability analyses and a state action plan for ocean acidification to build adaptation and resilience in communities affected by ocean acidification. The social vulnerability analysis method developed under this project will have broad applicability
Why we care Long-term observations of carbonate chemistry at U.S.-affiliated coral reef sites are critical to understanding the impact of ocean acidification on coral ecosystems over time.
What we are doing Incorporating an interdisciplinary approach, this project will collect, process, analyze, and steward continuous data measuring parts of ocean carbonate system, the ocean’s buffering system. Specifically, this project will include partial pressure of carbon dioxide, pH (measure of acidity), dissolved inorganic carbon (DIC) and total alkalinity to document seawater carbonate chemistry at a newly established climate monitoring site in Fagatele Bay, American Sāmoa.
Benefits of our work This work produces long-term, continuous, high-quality data of seawater carbonate chemistry needed to track where and how ocean chemistry is changing. The work will initially provide an increased understanding of the natural biogeochemical influences of reef carbon dioxide. In the future, this work will help determine if the magnitude of acidification occurring in the open ocean is also occurring at coral reefs. The buoy at this site will provide freely-available, high-quality carbon dioxide data people can use to better understand the carbon cycle of coral reefs in American Sāmoa and the impacts to coral ecosystems. This will be the only southern hemisphere Class III site in both the Atlantic and Pacific, spanning a large latitudinal gradient.
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.