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Chesapeake Bay inorganic carbon: spatial distribution and seasonal variability

Few estuaries have inorganic carbon datasets with sufficient spatial and temporal coverage for identifying acidification baselines, seasonal cycles and trends. The Chesapeake Bay, though one of the most well-studied estuarine systems in the world, is no exception. To date, there have only been observational studies of inorganic carbon distribution and flux in lower bay sub-estuaries. Here, we address this knowledge gap with results from the first complete observational study of inorganic carbon along the main stem. Dissolved inorganic carbon (DIC) and total alkalinity (TA) increased from surface to bottom and north to south over the course of 2016, mainly driven by seasonal changes in river discharge, mixing, and biological carbon dioxide (CO2) removal at the surface and release in the subsurface. Upper, mid- and lower bay DIC and TA ranged from 1000–1300, 1300–1800, and 1700–1900 μmol kg-1, respectively. The pH range was large, with maximum values of 8.5 at the surface and minimums as low as 7.1 in bottom water in the upper and mid-bay. Seasonally, the upper bay was the most variable for DIC and TA, but pH was more variable in the mid-bay. Our results reveal that low pH is a continuing concern, despite reductions in nutrient inputs. There was active internal recycling of DIC and TA, with a large inorganic carbon removal in the upper bay and at salinities < 5 most months, and a large addition in the mid-salinities. In spring and summer, waters with salinities between 10 and 15 were a large source of DIC, likely due to remineralization of organic matter and dissolution of CaCO3. We estimate that the estuarine export flux of DIC and TA in 2016 was 40.3 ± 8.2 × 109 mol yr-1 and 47.1 ± 8.6 × 109 mol yr-1. The estuary was likely a large sink of DIC, and possibly a weak source of TA. These results support the argument that the Chesapeake Bay may be an exception to the long-standing assumption that estuaries are heterotrophic. Furthermore, they underline the importance of large estuarine systems for mitigating acidification in coastal ecosystems, since riverine chemistry is substantially modified within the estuary.

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Impacts of urban carbon dioxide emissions on sea-air flux and ocean acidification in nearshore waters

Greatly enhanced atmospheric carbon dioxide (CO2) levels relative to well-mixed marine air are observed during periods of offshore winds at coastal sensor platforms in Monterey Bay, California, USA. The highest concentrations originate from urban and agricultural areas, are driven by diurnal winds, and peak in the early morning. These enhanced atmospheric levels can be detected across a ~100km wide nearshore area and represent a significant addition to total oceanic CO2 uptake. A global estimate puts the added sea-air flux of CO2 from these greatly enhanced atmospheric CO2 levels at 25 million tonnes, roughly 1% of the ocean’s annual CO2 uptake. The increased uptake over the 100 km coastal swath is of order 20%, indicating a potentially large impact on ocean acidification in productive coastal waters.

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“Burke-O-Lator” detecting concerning acidic levels in Humboldt Bay

The “Burke-o-Lator,” set up at the Hog Island Oyster Company’s hatchery on Humboldt Bay, examines ways seawater chemistry is being affected by ocean acidification. Unlike other oceanographic sensors that measure only acidity (pH), the Burke-o-Lator also collects information on seawater’s carbonate saturation state, which shows how difficult it is to build and maintain shell—directly related to the growth and development of shellfish. That data is made publicly available and streamed live at the Central and Northern California Ocean Observing System (CeNCOOS) website.

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Better regional ocean observing through cross-national cooperation: a case study from the Northeast Pacific

The ocean knows no political borders. Ocean processes, like summertime wind-driven upwelling, stretch thousands of kilometers along the Northeast Pacific (NEP) coast. This upwelling drives marine ecosystem productivity and is modulated by weather systems and seasonal to interdecadal ocean-atmosphere variability. Major ocean currents in the NEP transport water properties such as heat, fresh water, nutrients, dissolved oxygen, pCO2, and pH close to the shore. The eastward North Pacific Current bifurcates offshore in the NEP, delivering open-ocean signals south into the California Current and north into the Gulf of Alaska. There is a large and growing number of NEP ocean observing elements operated by government agencies, Native American Tribes, First Nations groups, not-for-profit organizations, and private entities. Observing elements include moored and mobile platforms, shipboard repeat cruises, as well as land-based and estuarine stations. A wide range of multidisciplinary ocean sensors are deployed to track, for example, upwelling, downwelling, ocean productivity, harmful algal blooms, ocean acidification and hypoxia, seismic activity and tsunami wave propagation. Data delivery to shore and observatory controls are done through satellite and cell phone communication, and via seafloor cables. Remote sensing from satellites and land-based coastal radar provide broader spatial coverage, while numerical circulation and biogeochemical modeling complement ocean observing efforts. Models span from the deep ocean into the inland Salish Sea and estuaries. NEP ocean observing systems are used to understand regional processes and, together with numerical models, provide ocean forecasts. By sharing data, experiences and lessons learned, the regional ocean observatory is better than the sum of its parts.

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Effects of environmental stressors on a habitat forming macroalga over evolutionary and ecological time scales

Fucus vesiculosus is a keystone species in the North Atlantic and Baltic Sea; any changes in its distribution or physical structure could have broad-reaching implications on many coastal ecosystems. It is therefore important to understand both how this important species has evolved in the past and adapted to historical changes in the environment but also how future environmental stress and changes will affect this species. When stress, for example from environmental change, affects a population, traits that make individuals more likely to survive will remain in the population. This is the fundamental basis of evolution, occurring over both short and long time scales. Climate change is
liable to exert a strong selective pressure on many species as it changes the environment inhabited by those species.

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Mid-Atlantic coastal acidification network seeking stakeholder perspectives on ocean acidification

The Mid-Atlantic Coastal Acidification Network (MACAN) is seeking perspectives on ocean acidification from members of commercial fishing, seafood, aquaculture, charter boat and recreational fishing organizations in the Mid-Atlantic. MACAN is a nexus of scientists, tribal, federal, and state agency representatives, resource managers, and affected industry partners who seek to coordinate and guide regional observing, research, and modeling of ocean and coastal acidification. MACAN would like to gain a better understanding of how stakeholders see coastal and ocean acidification affecting business operations or recreational fishing activities now or in the future. In addition, MACAN is seeking thoughts on opportunities to raise awareness and encourage participation in regional efforts to monitor for and adapt to coastal and ocean acidification.

You can help by participating in MACAN’s Stakeholder Outreach Survey. To access the survey, click on your industry or affiliation from the list below. The survey should take about 5-10 minutes to complete. Your responses are voluntary and anonymous. Please respond by June 14, 2019.

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Webinar: the Ocean Acidification Data Stewardship (OADS) and the Ocean Carbon Data System (OCADS) projects

When: Wednesday, May 8, 2019 6:00 PM – 7:00 PM CEST

Description: Liqing Jiang, a chemical oceanographer at NOAA/National Centers for Environmental Information (NCEI) and Associate Research Scientist at University of Maryland will discuss two data management projects residing at NCEI: the Ocean Acidification Data Stewardship (OADS) project and the Ocean Carbon Data System (OCADS) Project. OADS features rich metadata management and covers all types of ocean acidification data, including chemical, biological & model output. OCADS focuses on inorganic ocean carbon data and serves data producers from the entire international ocean carbon community.

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Ocean acidification in the IPCC AR5 WG II

OUP book