Ocean Acidification

OA Week 2021, Mediterranean Hub Session

Dr. Marta Álvarez, IEO-CSIC, Spain

Description:

The spectrophotometric pH method was firstly published in 1993 and the corresponding Standard Operation Procedure in 2007. However, seawater pH is loosely quality controlled due to the lack of reference materials and a well stablished metrology. Additionally, unpurities in the dye seam to interfere with the pH quantification, specially for high pH waters. A procedure was published to overcome this difficulty. Here we will present and discuss i) the direct comparision of pH measurements with unpurified and purified m-cresol dye over a range of oceanographic conditions; ii) the correction of unpur to pur dye pH estimates using the published method and iii) study the pH measurement and internal consistency improvement using pur dye.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Mediterranean Hub Session

Dr. Michele Giani, National Institute of Oceanography and Applied Geophysics (OGS), Italy

Description:

Two monthly time series of the carbonate system parameters were analyzed in the Gulf of Trieste, the northernmost coastal zone of the Mediterranean Sea, in a riverine influenced area, to detect trends. Water sampling was carried out at PALOMA Station, in the middle of the Gulf, from March 2009 to February 2020 and at C1-Miramare Station, close to the coast, from March 2011 to February 2020. Both sites are included in GOA–ON and ICOS-RI networks. pH and total alkalinity were measured by spectrophotometry and open cell potentiometric titration respectively, on water samples collected at four depths. The other parameters of the carbonate system were calculated using the software CO2Sys. Preliminary results show that, at both sites, the pH anomaly (i.e. deviation from the monthly mean) decreased by 0.002-0.004 units/yr. At both sites, pH at constant temperature of 25°C was inversely correlated with apparent oxygen utilization, showing a relevance of primary production and respiration processes on the carbonate system. Median pH (8.089-8.111) was lower at the bottom with the widest variability (interquartile range 0.100-0.167), due to respiration processes.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, North American Hub Session

Dr. Liqing Jiang, University of Maryland, USA

Description:

We compiled, quality-controlled, and synthesized two decades of discrete measurements of inorganic carbon system parameters, oxygen, and nutrient chemistry data from the North American continental shelves to generate a data product called the Coastal Ocean Data Analysis Product in North America (CODAP-NA). New consistency checks and outlier detections were used to QC the data. Future releases of this CODAP-NA product will use this core data product as the basis for cruise-to-cruise comparisons. This version (v2021) of the CODAP-NA is comprised of 3391 oceanographic profiles from 61 research cruises covering all continental shelves of North America, from Alaska to Mexico in the west and from Canada to the Caribbean in the east. Data for 14 variables (temperature; salinity; dissolved oxygen content; dissolved inorganic carbon content; total alkalinity; pH on total scale; carbonate ion content; fugacity of carbon dioxide; and substance contents of silicate, phosphate, nitrate, nitrite, nitrate plus nitrite, and ammonium) have been subjected to extensive QC. CODAP-NA is available as a merged data product (https://www.ncei.noaa.gov/data/oceans…). The original cruise data have also been updated with data providers’ consent and summarized in a table with links to NOAA’s National Centers for Environmental Information (NCEI) archives (https://www.ncei.noaa.gov/access/ocea…)

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, North American Hub Session

Dr. Wiley Evans, Hakai Institute, Canada

Description:

Information on marine CO2 system variability has been limited along the Inside Passage of the Pacific Northwest despite the region’s rich biodiversity, abundant fisheries, and developing aquaculture industry. Beginning in 2017, the Alaska Marine Highway System M/V Columbia has served as a platform for surface underway data collection while conducting twice weekly ~1600-km transits between Bellingham, Washington and Skagway, Alaska. This effort provided the first characterization of the variability, severity, and timing of adverse pH and aragonite saturation state (Ωarag) conditions across the region. Lowest pH was seen in confined tidally-mixed zones in autumn; whereas lowest Ωarag was seen in areas of high glacial melt in summer. Time-of-detection estimates revealed the tidally-mixed zones to be sentinel observing sites with relatively short time spans of observation needed to capture seawater pCO2 increase equivalent to the contemporary atmospheric CO2 trend. Anthropogenic CO2 estimates showed large time and space variability, the impacts of which were greater change in winter pH and larger change in summer Ωarag. Differing spatial patterns of severe pH and Ωarag, and the differential response to anthropogenic CO2, likely have implications for vulnerable species and should be considered within the scope of tracking ocean acidification. Here we characterize the 1.5°C acidification level as the theoretical extent of acidification along the Inside Passage if society limits global warming to preferably 1.5°C as per the Paris Agreement, and show that half the acidification experienced thus far since the start of the industrial era is expected over the coming 15 years at our current atmospheric CO2 trajectory.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, North American Hub Session

Dr. Orion Norzagaray, Instituto de Investigaciones Oceanológicas-Universidad Autónoma de Baja California, Mexico

Description: Coral reefs and coral communities from the Eastern Tropical Pacific (ETP) develop under harsh conditions, since they live in environments with low temperature, high nutrient content and sub-saturated with regard to aragonite. These conditions convert this region, and the ecosystems inhabiting there, in natural laboratories for ocean acidification studies (OA) on corals. Studies on carbonate balance in these ecosystems indicate that they present low production values, commonly based on a small number of species. In addition, studies on the dynamics of the carbonate system in these environments highlight that the seasonal controls vary between regions, promoted by oceanographic processes, which have a local to regional footprint. This talk aims to show relevant aspects of the carbonate cycle in these environments, specifically those on the coasts of Mexico, and place them in the context of OA.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

Elliot Scanes from the University of Technology Sydney talks to us about his FEMS Microbiology Ecology

Read this article: Microbiome response differs among selected lines of Sydney rock oysters to ocean warming and acidification | FEMS Microbiology Ecology | Oxford Academic (oup.com)

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Dr. Nicolas Gruber, Professor of Environmental Physics, Eidgenössische Technische Hochschule (ETH Zürich), Switzerland

Description:

The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 5 Attribution & Blue Carbon

Dr. Scott Doney, Joe D. and Helen J. Kington Professor in Environmental Change, University of Virginia, USA

Description:

Uptake of anthropogenic carbon dioxide from the atmosphere by the surface ocean is leading to global ocean acidification, but regional variations in ocean circulation and mixing can dampen or accelerate apparent acidification rates. Excess nutrient pollution can also result in coastal acidification in estuaries and near shore regions. Both climate variability and nutrient pollution exacerbate the ecological press from rising atmosphere CO2 and can cause extreme acidification events that are detrimental to ecosystem health and fisheries.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 5 Attribution & Blue Carbon

Dr. Rushingisha George, Researcher, Tanzania Fisheries Research Institute (TAFIRI), Tanzania

Description:

As concentration of anthropogenic CO2 continues to increase in the atmosphere, both ocean warming and acidification will continue to increase globally. This can have both negative and positive impacts on the health and function of seagrasses, which are key primary producers and ecosystem engineers in the coastal zone. The key physiological processes (photosynthesis, calcification and respiration) of these plants operate over a wide range of climatic factors (temperature, CO2, dissolved oxygen etc.) and their response can serve to mitigate the impacts of ocean acidification on short-time scales. This talk will focus on the responses of seagrass physiological processes to elevated climatic factors (under both current and future conditions) in the water column, and how these responses affect the pH of the water column as well as on the effect of the tidal variability on pH of seagrass meadows and adjacent coastal habitats. Research findings show that seagrass physiological processes respond differently to elevated climatic factors and their interaction govern the pH of the system. The effect of physiological processes on pH of seagrass meadows of intertidal waters depend on the water level and percentage cover, and is highest during low spring tides. Photosynthetic uptake of dissolved inorganic carbon (DIC) can raise the mean pH of seagrass meadows, and adjacent mangrove and coral reef habitats to 5% above that of adjacent open ocean during daytime at high tide. These findings show that healthy seagrass meadows offer a huge potential to mitigate the impacts of ocean acidification, as their photosynthetic uptake of DIC have been shown raise the mean pH of seagrass meadows, and adjacent mangrove and coral reef habitats to 5% above that of adjacent open ocean during daytime at high tide. Therefore, reducing anthropogenic stressors such as eutrophication by land-based pollution sources, among others, will make seagrass meadows healthy and resilient to elevated water temperatures while mitigating the impacts of ocean acidification on temporal scales.”

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Isabella Lövin, Former Deputy Prime Minister and Minister for Environment and Climate, Sweden

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Dr. Jamie Shutler, Associate Professor in Earth Observation, University of Exeter, UK

Description:

The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 4 OceanSODA – The Satellite Oceanographic Datasets for Acidification Project

Ms. Hannah Green, PhD Student, University of Exeter and Plymouth Marine Laboratory, UK

Description: The potential of satellite observed salinity for observing the surface water carbonate system was identified some time ago and this space-based capability, combined with established temperature observations from space, is now enabling the development of novel satellite observation-driven acidification and inorganic carbon assessments (eg Land et al., 2019; Gregor and Gruber, 2021; Green et al., 2021; Quilfen et al., 2021). The European Space Agency funded Satellite Oceanographic Datasets for Acidification project (OceanSODA) aimed to establish the role that satellite-based Earth Observations can play in supporting and expanding research and monitoring in ocean acidification. The project, now nearly complete, had two distinct foci, scientific advancement and downstream impact assessments. The scientific advancements have produced regional and global time-series data of the surface water carbonate conditions with well characterised accuracies. The downstream assessments included the characterization and analysis of how upwelling (of low pH waters), compound (heatwaves and high acidity) events, and large river outflows (of low pH waters) impact the carbonate system, and how these conditions could affect marine organisms and ecosystems. The project has also identified how satellite observations can be used for, and are critical for, observing Arctic carbonate system conditions. These capabilities and datasets are now beginning to be noticed by non-scientific user groups as they hold potential for guiding management and policy decisions. This plenary session will discuss how this work has evolved, highlighting the scientific advances, identify potential new scientific opportunities, and discuss how these capabilities are now being noticed by early adopters and stakeholders to support decision making, by considering a range of users from shellfish farmers through to regional resources managers advising US and Canadian state governors.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 3 GOA-ON Goal #3 – Acquire and exchange data and knowledge necessary to optimize modeling for OA and its impacts

Dr. Manuel Barange, Director of the Fisheries and Aquaculture Policy and Resources Division, Food and Agriculture Organization of the United Nations (FAO)

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 3 GOA-ON Goal #3 – Acquire and exchange data and knowledge necessary to optimize modeling for OA and its impacts

Dr. Fabian Gomez, Research Scientist, Northern Gulf Institute, Mississippi State University, and NOAA Atlantic Oceanographic and Atmospheric Laboratory, USA

Description:

Ocean Acidification (OA) progression is affected by multiple factors, such as ocean warming, biological production, and river runoff. Here we used an ocean-biogeochemical model to examine the drivers of the OA spatiotemporal variability in the Gulf of Mexico (GoM) during 1981-2014. The model showed negative pH and aragonite saturation state trends (ΩAr), linked to increasing levels of atmospheric CO2, which were close to values reported for the Subtropical North Atlantic. However, significant departures from the basin-mean trends were obtained over the northern GoM inner shelf, where the sign of the trends was positive. Model sensitivity analyses showed that OA progression in this last region was counteracted by enhanced alkalinity from the Mississippi-Atchafalaya River System (MARS). The model results also showed interdecadal changes in the OA indicators linked to the 1997-98 climate shift. We detected a stronger OA in the northern GoM shelf during 1999-2014, driven by interdecadal changes in the MARS’s ratio of alkalinity to dissolved inorganic carbon. Away from the northern GoM shelf, surface warming during 1981-1998 and a weak surface cooling during 1999-2014 promoted a stronger positive trend for ΩAr while counteracted the trend changes for pH and partial pressure of CO2. Our findings highlight that river alkalinity is a key driver of the low-frequency carbon system variability and emphasize the need for considering realistic freshwater chemistry fluxes to properly assess acidification in coastal waters.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 3 GOA-ON Goal #3 – Acquire and exchange data and knowledge necessary to optimize modeling for OA and its impacts

Dr. Samantha Siedlecki, Department of Marine Sciences, University of Connecticut, USA

Description:

Corrosive and hypoxic events in coastal waters are of increasing concern to local fisheries. Many important species (oysters, crabs, phytoplankton, zooplankton) in Washington and Oregon coastal waters are currently experiencing or are expected to feel effects of ocean acidification. Direct effects have been observed on the $100 million shellfish industry, and additional indirect economic impacts could impact the finfish industry through loss of prey species. Recent findings from the West Coast Ocean Acidification and Hypoxia Panel and the Washington Blue Ribbon Panel Addendum emphasize the need to use models to assess probable future conditions at local and regional scales. It is now possible to simulate important processes for regional Ω, pH, and hypoxia variability due to the higher spatial and temporal resolution of models combined with more comprehensive observations. The ability to predict the intensity of hypoxic and corrosive conditions, spatial variability of these conditions, and changes in their duration could be of considerable benefit to managers. These abilities require models to forecast and project variability with accurate representations of processes important to determining that variability. A suite of forecast and projections have been in development for the Pacific Northwest coast including a short-term forecast (LiveOcean, 72 hour) and some high-emissions scenario projections out to 2100. These simulations enable us to attribute regional variability to important processes like regional freshwater influence, water column metabolism, and changes in buffer capacity. The simulations also allow us to explore impacts of future emission scenarios on the regional expression of those processes within the context of Ω and pH variability on a range scales. In this work, we discuss methods for evaluating model forecasts and projections to ensure they achieve well-simulated conditions for the right reasons, showcase results of simulating important processes attributed to determining variability in the region, and determine the implications for these processes in a future scenario. Our results will shed light on the extent and timing of the risks to local ecosystems and provide critical guidance to those concerned with mitigation of and adaptation to the threat of ocean acidification.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 2 – GOA-ON Goal #2 – Improve our understanding of ecosystem response to OA

Dr. Carla Edworthy, Postdoctoral Researcher, The South African Institute for Aquatic Biodiversity, South Africa

Description:

Ocean acidification monitoring is still limited in South Africa, especially in our unique, productive and dynamic coastal areas. My talk will be a story of my journey with ocean acidification research in South Africa. I will discuss how we started our research on OA, how we progressed, how we made use of our opportunities and how we overcame several limitations. The talk will focus on our monitoring efforts and how we developed best practice methods for designing a simple and appropriate strategy for monitoring OA in an understudied region. I will also discuss how this information serves to assess the ecosystem effects of OA in South Africa, on coastal species and resources relevant to people. I will also add some thoughts for future research.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

OA Week 2021, Plenary Session 2 GOA-ON Goal #2 – Improve our understanding of ecosystem response to OA

Dr. Chris Cornwall Research Fellow & Lecturer, Victoria University of Wellington, New Zealand

Description:

Ocean acidification (OA) is a major threat to the persistence of biogenic reefs throughout the world’s ocean. Coralline algae are comprised of high magnesium calcite and have long been considered one of the most susceptible taxa to the negative impacts of OA. In a recent meta-analysis/systematic review, we uncover some consistent and some inconsistent impacts of ocean acidification: most coralline algae experienced reduced abundance, calcification rates, recruitment rates, and declines in pH within the site of calcification in laboratory experiments simulating ocean acidification or at naturally elevated CO2 sites. There were no other consistent physiological responses of coralline algae to simulated OA (e.g. photo-physiology, mineralogy and survival). OA is the dominant driver in the majority of laboratory experiments where other local or global drivers were assessed. The interaction between OA and any other single driver was often additive, though factors that changed pH at the surface of coralline algae (light, water motion, epiphytes) acted antagonistically or synergistically with OA more than any other drivers. Coral reefs will be severely impacted by ocean warming and associated marine heatwaves. Reefs that could fair well under marine heatwaves currently have high contributions of coralline algae. However, the ability of these reefs to continue to calcify will be threatening by intensifying ocean acidification.

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information, please visit www.goa-on.org

The IAEA’s Environment Laboratories have been at the forefront of ocean research since 1961, and this year are celebrating 60 years of addressing global ocean issues. From marine radioactivity to plastic pollution to climate change and more, the laboratories use nuclear science and technology to understand our biggest emerging challenges.

OA Week 2021

Promotional video for the 5th International Symposium on the Ocean in a High CO2 World Lima, Peru

13-16 September 2022

Ocean Acidification Week 2021 was sponsored by the following organizations:

(1) GOA-ON, the Global Ocean Acidification Observing Network,

(2) NOAA, the United States National Oceanic & Atmospheric Administration,

(3) IAEA OA-ICC, the International Atomic Energy Agency – Ocean Acidification International Coordination Centre, and

(4) IOC-UNESCO – the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization

For more information about GOA-ON, please visit www.goa-on.org

For more information about the High CO2 Symposium, please visit http://www.highco2-lima.org/index.htm