Ocean acidification (OA) has significant scientific and societal ramifications including the alteration of ocean biogeochemistry, ecological consequences associated with altered ecosystems, and economic losses due to the decreased survival of commercially important organisms. Yet few time series and high resolution spatial and temporal measurements exist to track the existence and movement of low pH and low carbonate saturation (Ù) water, specifically in coastal regions where finfish, lobster, and wild stocks of shellfish are located. Past ocean acidification monitoring efforts (surface buoys with pH or sensors that measure partial pressure of carbon dioxide, or pCO2, flow-through pCO2 systems utilized by research vessels, water column sampling during large field campaigns) have either low spatial resolution (mooring) or high cost and low temporal and spatial resolution (research cruises). Therefore, there is a critical need to deploy new, cost-effective technologies that can routinely provide high resolution water column OA data on regional scales in our coastal ocean. Autonomous underwater profiling gliders have proven to be a robust technology that fulfills this role. A variety of sensors have successfully been mounted on Slocum gliders; however, no direct measurements of ocean pH have been collected by pH sensors mounted on these gliders. The researchers will develop the integrated glider platform and sensor system for sampling pH and possibly Ù in the water column of the coastal ocean on a regional scale. This project will result in a new commercially available glider pH sensor suite that will provide the foundation of what could become a real-time national coastal OA monitoring network with the capability of serving a wide range of users. Additionally, the integration of simultaneous measurements from multiple sensors on one glider will allow one to distinguish interactions between the physics, chemistry, and biology of the ecosystem.
The researchers will modify and integrate a deep rated version of the Ion Sensitive Field Effect Transistor (ISFET)-based pH sensor, the Deep-Sea DuraFET pH sensor system, into a Slocum glider. They will test the new sensor suite via three glider deployments on the U.S. Northeast Shelf, deliver the OA data in real-time, and examine pH/Ù dynamics in habitats of commercially important fisheries. The project will benefit with rigorous groundtruthing via coordination of the high resolution glider mapping of pH and Ù side-by-side NOAA OAP's (Ocean Acidification Program) planned ECOA (East Coast Ocean Acidification) cruise II where a full suite of carbonate parameters (pCO2, pH, dissolved inorganic carbon, total alkalinity, and oxygen) will be measured either underway or on board ship. High spatial and temporal resolution in situ pH measurements and Ù estimations will be provided in habitats of commercially important fisheries in the U.S. Northeast Shelf. This open accessible, automated real-time data will be made available through RUCOOL (Rutgers University Center for Ocean Observing Leadership), MARACOOS (Mid-Atlantic Regional Association Coastal Ocean Observing System), and THREDDS (Thematic Real-time Environmental Data Distribution System). The data produced from this new technology will allow the researchers and the community to track the movement of low pH/Ù water, understand the variability of pH/Ù, predict how mixing events and circulation will impact pH/Ù across the shelf, identify high-risk regions and populations of commercially important species that are more prone to periods of reduced pH/Ù, and ultimately will enable more informed management of essential habitats in the future, more acidic oceans.
