Ocean Acidification

OA Week 2021, PI-TOA (Pacific Islands & Territories) Hub Session

Ms. Aleluia Taise, School of Biological Science, Victoria University of Wellington, New Zealand

Description:

Caulerpa is a widely distributed genus of chlorophytes. They are important for their dietary, social, and coastal ecosystem values. Caulerpa is one of the rare few genera that have species both with and without CO2 concentrating mechanisms (CCMs) that allow active uptake of HCO3-. Two of the most common Caulerpa species in New Zealand, C. brownii and C. geminata, could have vastly different responses to ocean acidification (OA). This is because of their divergent dissolved inorganic carbon (DIC) uptake. C. geminata possesses a CCM while C. brownii does not have a CCM. We investigated growth, photo-physiology and DIC utilization responses by C. brownii and C. geminata at four mean seawater pH treatments (8.03, 7.93, 7.83 and 7.63). In all cases, mean and variability in growth rates of C. brownii increased under OA scenarios, while growth rates for C. geminata declined under OA. This concurs with predictions that non-CCM species will be gaining benefits from additional CO2, while species with a CCM may gain less benefits from additional CO2, while at the same time demonstrating that DIC use alone does not predict responses to OA. We show divergent responses of two Caulerpa species that could have implications for their future abundance in Australasia.

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, PI-TOA (Pacific Islands & Territories) Hub Session

Ms. Evelyn Ikelau Otto, Palau International Coral Reef Center (PICRC), Palau

Description:

This presentation will discuss some of the work that is going on at PICRC in regards to climate change, specifically Ocean Acidification. It will highlight the exciting work that has been conducted in Palau and at the Center as well as highlight some setbacks that were experienced as PICRC develops their OA and water quality monitoring programs.

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, PI-TOA (Pacific Islands & Territories) Hub Session

Ms. Miriama Vuiyasawa, The University of the South Pacific, Fiji

Description:

Blue Carbon ecosystems such as mangrove forests and seagrass meadows have the ability to sequester carbon dioxide and store fixed carbon. As a result of this sequestration, there is less dissolved carbon dioxide available in the ocean water column to form acidic compounds. Therefore, restoring blue carbon habitats can help mitigate the effects of ocean acidification (OA) on coastal communities. In 2018 the Institute of Applied Sciences at the University of the South Pacific was awarded a 2-year project to pilot the use of blue carbon in local mitigation of OA in Fiji. The main objective was to increase coastal resilience through climate change mitigation and better understanding of the role of blue carbon in OA mitigation through support of an existing coastal restoration project. The project was conducted in 4 villages in Viti Levu Bay, Fiji Islands and activities involved mangrove forest restoration, monitoring ocean acidification, raising awareness about observations of ecosystem health at the restored site. The work also provided capacity building for local scientists and early career junior staff on OA monitoring. Discrete water samples were collected at all four sites on a monthly basis and chemical analyses were conducted using protocols from the GOA-ON and an In a Box equipment kit donated by the Ocean Foundation. Data collected includes pH, total alkalinity, salinity and water temperate from which other OA parameters were determined. Along with OA monitoring, a total of 0.7925 ha of mangrove forest (more than (6000 seedlings) was planted with the assistance of the local Navuniivi community. Long term monitoring and more restorative work is needed at the project sites to fully understand and assess the benefits of the restorative efforts and its potential mitigation of OA. Several challenges were encountered, particularly with equipment breakdown and maintenance, and the limited resources to perform monitoring work. Despite these challenges, the project successfully collected OA monitoring data, which was the first dataset for the area and thus contributed to SDG 14 goal for Fiji. The mangrove restorative work was also a huge achievement with great community buy-in that resulted in a successful community collaborative project.

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, Arctic Hub Session

Dr. Alexander Polukhin, Shirshov Institute of Oceanology, Russian Academy of Sciences, Russia

Description:

The processes occurring in the areas of the outer shelf and the continental slope of the Siberian epicontinental seas play a huge role in the regulation of the biogeochemical regime and substance fluxes, and the formation of biological productivity. These processes are associated with current climatic trends, since it is in the area of the Arctic continental slope that the current trend of a decrease in ice cover and an increase in the duration of the ice-free period in the Arctic is most pronounced. One of the most important characteristics of matter fluxes in Arctic ecosystems is the exchange of carbon dioxide at the ocean-atmosphere interface. As a result of our studies, it became obvious that, over a significant latitudinal extent of the water in the area of the outer shelf and continental slope of the Kara and Laptev seas, in the summer season, CO2 flows from the atmosphere into the surface layer of the sea. And the main factor affecting the aragonite saturation on the shallow shelf of the seas is the river runoff due to an increase in the removal of carbon in various forms from the land.

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, Arctic Hub Session

Dr. Libby Jones, Institute of Marine Research, Norway

Description:

Seasonal cycling in carbon and nutrients, with implications for ocean acidification, was investigated in the context of changes in sea ice cover, meltwater inputs, mixing and biological processes in the Barents Sea and Arctic Ocean (Nansen Basin). In August 2019, the summer ice edge was located 80N and the upper water column was generally warm and fresh. Primary production had reduced concentrations of nutrients and dissolved inorganic carbon (CT), particularly in the ice-free waters. North of the ice edge, meltwater inputs reduced total alkalinity (AT), the chemical buffering capacity of seawater, through dilution. By December, the winter ice pack extended to 78N and created more Arctic-like conditions. Mixing and remineralisation resulted in increased concentrations of nutrients and CT in the water column. The imprint of summer processes was observed with lower CT and AT in ice-covered surface waters. The central Barents Sea revealed low seasonality, where reduced AT and Arctic-like conditions characterized the water column. Atlantic Water inflow in the south and north supplied the surface layer with AT to counteract acidification effects. Future warming, loss of sea ice and Atlantification likely enhance biological carbon uptake, reduce effects of meltwater dilution and buffer against acidification in the Barents Sea. This study is a contribution to the Nansen Legacy project.

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, Arctic Hub Session

Dr. Jens Terhaar, University of Bern, Switzerland

Description:

The Arctic Ocean is particularly vulnerable to ocean acidification due to its naturally low pH and saturation states. Here, we analyse ocean acidification in the Arctic Ocean over the 21st century across models from the latest Coupled Model Intercomparison Project Phase 6 (CMIP6). Compared to the previous model generation (CMIP5), models generally better simulate maximum sea surface densities in the Arctic Ocean and consequently the transport of Cant into the Arctic Ocean interior. Moreover, in CMIP6 the inter-model uncertainty of projected changes over the 21st century in Arctic Ocean saturation states of aragonite (Ωarag) and calcite (Ωcalc) averaged over the upper 1000 m is reduced by 44–64 %. The strong reduction in projection uncertainties of Ωarag and Ωcalc can be attributed to compensation between Cant uptake and total alkalinity reduction in the latest models. Specifically, models with a large increase in Arctic Ocean Cant over the 21st century tend to simulate a relatively weak concurrent freshening and alkalinity reduction, while ESMs with a small increase in Cant simulate a relatively strong freshening and concurrent total alkalinity reduction. Even under the low-emissions Shared Socioeconomic Pathway 1-2.6 (SSP1-2.6), basin-wide averaged Ωarag undersaturation in the upper 1000 m occurs before the end of the century.

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, LAOCA (Latin America & Caribbean) Hub Session

Dr. María Eugenia Becherucci, Laboratorio de Ecología, Instituto de Investigaciones Marinas y Costeras (IIMyC: UNMdP-CONICET), Argentina

Description:

Nutrient input drives macroalgal blooms and increases in photosynthetic activity in coastal ecosystems. An intense macroalgal photosynthetic activity can increase the surrounding pH and counteract the acidification that often follows an eutrophication process. This hypothesis was tested with field sampling and experiments in a macrotidal (up to 9 m in amplitude) coastal system within a semi-desert region with contrasting eutrophic conditions and Ulva lactuca blooms in the northern Argentinean Patagonia (San Antonio Bay). The results indicate that daily pH variability during low tide could be controlled by the photosynthetic activity of Ulva lactuca under eutrophic conditions. At seasonal scale, the pH variations were related to environmental features, particularly seawater temperature. Both environmental (i.e. high solar radiation, negligible freshwater inputs and large tidal action) and anthropogenic nutrient inputs into the studied area promote the Ulva lactuca blooms, which in turn increases the surrounding pH in well oxygenated seawater through the intense photosynthetic activity.

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, Arctic Hub Session

Dr. Nina Bednarsek, Southern California Coastal Water Research project (SCCWRP), USA

Description:

Exposure to the impact of ocean acidification (OA) is increasing in high-latitudinal productive habitats. Pelagic calcifying snails (pteropods), a significant component of the diet of economically important fish, are found in high abundance in these regions. This presentation will focus on the integrated risk assessment in the Eastern Pacific subpolar gyre, including the Gulf of Alaska (GoA), Bering Sea, and Amundsen Gulf. The risk for pteropod populations was determined by integrating measures of OA exposure, biological sensitivity, and resilience. Exposure was based on physical-chemical hydrographic observations and regional biogeochemical model outputs. Biological sensitivity was based on pteropod morphometrics and shell-building processes, including shell dissolution, density and thickness. Resilience and adaptive capacity were based on species diversity and spatial connectivity, derived from the particle tracking modelling. An integrated risk evaluation based on multiple approaches assumes a high risk for pteropod population persistence with intensification of OA in the high latitude eastern North Pacific. Such comprehensive understanding would permit improved prediction of ecosystem change relevant to effective fisheries resource management, as well as a more robust foundation for monitoring ecosystem health and investigating OA in high-latitudinal habitats.

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, Arctic Hub Session Dr. Nadja Steiner, Fisheries and Oceans Canada, Canada

Description:

We will present an evaluation of regional trends in ocean acidification and accompanying environmental stressors for the Arctic. Evaluations will be presented for historical and projection runs and for a variety of CMIP5 and CMIP6 models and scenarios. The models tend to show high consistency in ocean acidification trends, but differ in their initial conditions, which leads to constant biases among the models. Model projections show little difference for different scenarios over a 10-20 year timescale, but diverge afterwards with clear differences in ocean acidification for high and low emission scenarios. Several regions show continuous aragonite undersaturation already within the historical time period (before 2015).

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

Mr. Saul Ciriaco, L’Area Marina Protetta di Miramare, Italy

Description:

Since 1995 he has been part of the management staff of the Miramare MPA (managed by WWF Italy on behalf of the Ministry of the Environment), as the person responsible for monitoring and research activities in the sea. In recent years he has been working with other research institutes on environmental restoration projects on marine forests and Pinna nobilis. He is a member of the Shoreline Research Cooperative, on behalf of which he works on projects related to the monitoring and management of MPAs in the Mediterranean.

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, LAOCA (Latin America & Caribbean) Hub ​Session

Mr. Miguel Gomez Batista, Centro de Estudios Ambientales, Cuba

Description:

Cuban Observatory for the Study of Ocean Acidification was created in 2017 through International Collaboration Project financed by International Atomic Agency Technical Cooperation Department and National Science Project funded by Science Ministry of Cuba. The observatory has different sections dealing with the i) measurement of carbonate cycle variables (pH, AT) in seawater (Field and laboratory measurements), ii) use of natural archives to reconstruct temperature and pH profiles (historical trend) and iii) laboratory experiments to assess the effect of OA over local marine species. The main results of the observatory until date are linked with the report of carbon cycle variables at IODE web page as part of national compromise with SDG 14.3.1. Some challenges for regular functioning of the observatory are related with the access to Certified Reference Materials, the calibration and maintenance of in situ probes and networking collaboration at national and international level.

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, LAOCA (Latin America & Caribbean) Hub Session

Ms. Patricia Macías Mora, Instituto Público de Investigación en Acuicultura y Pesca, Ecuador

Description:

El Instituto Público de Investigación en Acuicultura y Pesca a través del programa institucional denominado Variabilidad climática, genera un sistema de monitoreo de variables físico químicas y biológicas relevantes para determinar la acidificación del océano en dos sitios frente a la costa ecuatoriana, Salinas y Puerto López, aplicando los procedimientos operacionales estandarizados (SOP) para muestras de agua.

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

A basic tutorial on how to use two basic functions in the carbonate chemistry package “Seacarb” for R.

• 1) Install and load the Seacarb package (0:49)
• 2) An example calculation where we use the carb function to constrain the carbonate system based on two measured input variables. (1:26)
• 3) An example calculation where use the “errors” function to constrain the propagated uncertainty in the carbonate system, which originates from analytical uncertainty in various input variables. (9:13)

Another video with a basic tutorial on the CO2SYS macro for excel can be found here:

• CO2Sys for excel tutorial – YouTube

Further reading (open access):

• 1) Home – OBPS – Ocean Best Practices System
• 2) Routine uncertainty propagation for the marine carbon dioxide system – ScienceDirect

OA Week 2021, North American Hub Session

Dr. Jan Newton & Dr. Melissa Poe, University of Washington, USA

Description:

We present a place-based, transdisciplinary approach to assess ocean acidification vulnerability on a regional scale, highlighting a collaborative social-ecological research effort. Our study area, the Olympic Coast of Washington State, has been home for millennia to four coastal treaty tribes, and is already experiencing effects of ocean acidification, hypoxia, and marine heatwaves, which pose risks to marine resources that coastal communities and tribes depend on for their well-being. We bring together a variety of biophysical and social data across ocean spatial gradients and human systems to better understand the whole, to anticipate the effect of cumulative stressors, and to outline adaptive responses for healthy and resilient communities. Our place-based approach to assess regional vulnerability follows a process: scope local risk and priority needs; understand social importance of marine species; analyze variability in chemical and biological data; project future ocean conditions; assess frequency, duration, and location of harmful oceanographic events; evaluate risks to resources important to community partners; analyze socioeconomic conditions; assess social vulnerability to OA; identify community-driven strategies to respond to threats and increase adaptive capacity; provide critical information to decision-makers to prepare for and respond to OA vulnerabilities; monitor, evaluate, and reiterate. Working collaboratively, the project has strengthened regional partnerships, brought together a diverse constituency, and shown more deeply how connected things are and need to be going forward.

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. 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)