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NE Atlantic Ocean acidification workshop

On April 28, 2021 the International Alliance to Combat Ocean Acidification, the Global Ocean Acidification Observing Network NE Atlantic Hub and Because the Ocean Initiative will be hosting a virtual workshop that brings together climate and environment policy leads, marine managers, and OA scientists from across the NE Atlantic region to discuss:

• Government Led Responses to Ocean Acidification
• Understanding Biological Impacts to Keystone Fisheries and Aquaculture
• Monitoring and Regional Networks that Can Help Inform Government Response and Investments

This workshop will occur April 28  1400 CET- 1645 CET and is tailored for participants in:

Belgium  Canada   Denmark   France   Finland   Germany   Greenland   Iceland   Ireland   Netherlands   Norway Poland   Portugal   Spain   Sweden   United Kingdom

Register here:

It is imperative that governments and civil society continue to advance the suite of science and policy actions that will be needed to support food security and sovereignty, increase resilience of marine ecosystems and build a sustainable ocean economy. This is reflected in commitments to the UNFCCC, UN Sustainable Development Goals (SDGs), and is especially relevant for supporting the target of SDG 14.3 to “Minimize and address the impacts of ocean acidification”.

As the science, research and observed impacts of ocean acidification continue to grow, there is an ongoing need for increased knowledge exchange and expertise on the substance and process for developing local, regional and national responses in the face of cumulative climate driven ocean change.

OA_NE Atlantic Workshop_Save the Date_April 28 _Flyer

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Accounting for OA across vulnerability and risk assessments

April 15 at 1:00pm PST/ 4:00pm EST

1:00pm in British Columbia and Seattle

4:00pm in Washington DC

6:00am in Cairns Australia on April 16

Length: 90 minutes


Webinar Overview:

This 90-minute webinar will provide a snapshot of OA vulnerability and risk assessments that have already been conducted and highlight strategies and methodologies that account for socio-economic and cultural vulnerabilities.


Continue reading ‘Accounting for OA across vulnerability and risk assessments’

Viral-mediated microbe mortality modulated by ocean acidification and eutrophication: consequences for the carbon fluxes through the microbial food web

Anthropogenic carbon emissions are causing changes in seawater carbonate chemistry including a decline in the pH of the oceans. While its aftermath for calcifying microbes has been widely studied, the effect of ocean acidification (OA) on marine viruses and their microbial hosts is controversial, and even more in combination with another anthropogenic stressor, i.e., human-induced nutrient loads. In this study, two mesocosm acidification experiments with Mediterranean waters from different seasons revealed distinct effects of OA on viruses and viral-mediated prokaryotic mortality depending on the trophic state and the successional stage of the plankton community. In the winter bloom situation, low fluorescence viruses, the most abundant virus-like particle (VLP) subpopulation comprising mostly bacteriophages, were negatively affected by lowered pH with nutrient addition, while the bacterial host abundance was stimulated. High fluorescence viruses, containing cyanophages, were stimulated by OA regardless of the nutrient conditions, while cyanobacteria of the genus Synechococcus were negatively affected by OA. Moreover, the abundance of very high fluorescence viruses infecting small haptophytes tended to be lower under acidification while their putative hosts’ abundance was enhanced, suggesting a direct and negative effect of OA on viral–host interactions. In the oligotrophic summer situation, we found a stimulating effect of OA on total viral abundance and the viral populations, suggesting a cascading effect of the elevated pCO2 stimulating autotrophic and heterotrophic production. In winter, viral lysis accounted for 30 ± 16% of the loss of bacterial standing stock per day (VMMBSS) under increased pCO2 compared to 53 ± 35% in the control treatments, without effects of nutrient additions while in summer, OA had no significant effects on VMMBSS (35 ± 20% and 38 ± 5% per day in the OA and control treatments, respectively). We found that phage production and resulting organic carbon release rates significantly reduced under OA in the nutrient replete winter situation, but it was also observed that high nutrient loads lowered the negative effect of OA on viral lysis, suggesting an antagonistic interplay between these two major global ocean stressors in the Anthropocene. In summer, however, viral-mediated carbon release rates were lower and not affected by lowered pH. Eutrophication consistently stimulated viral production regardless of the season or initial conditions. Given the relevant role of viruses for marine carbon cycling and the biological carbon pump, these two anthropogenic stressors may modulate carbon fluxes through their effect on viruses at the base of the pelagic food web in a future global change scenario.

Continue reading ‘Viral-mediated microbe mortality modulated by ocean acidification and eutrophication: consequences for the carbon fluxes through the microbial food web’

Conserve and sustainably use the oceans, seas, and marine resources

Continue reading ‘Conserve and sustainably use the oceans, seas, and marine resources’

Reducing ocean acidification by removing CO2: two targets for cutting-edge research

Is it possible to simultaneously address the increase of the concentration of carbon dioxide (CO2) in the atmosphere and the resulting acidification of the oceans? The research of the project DESARC-MARESANUS, a collaboration between the Politecnico di Milano and the CMCC Euro-Mediterranean Center on Climate Change Foundation, explores the feasibility of this process, its chemical and environmental balance, and the benefits for the marine sector, focusing on the Mediterranean basin.

It is now widely recognized that in order to reach the target of limiting global warming to well below 2°C above pre-industrial levels (as the objective of the Paris agreement), cutting the carbon emissions even at an unprecedented pace will not be sufficient, but there is the need for development and implementation of active Carbon Dioxide Removal (CDR) strategies. Among the CDR strategies that currently exist, relatively few studies have assessed the mitigation capacity of ocean-based Negative Emission Technologies (NET) and the feasibility of their implementation on a larger scale to support efficient implementation strategies of CDR. The ocean plays a particular role in the climate system acting as significant sink of atmospheric heat and CO2; this has caused the additional hazard of ocean acidification, that is the pH reduction of ocean seawater since the pre-industrial period, that is unprecedented in the last 65 million years and has significant implications for marine organisms affecting their metabolic regulation and capability to form calcium carbonate, destabilizing the ecosystem and ultimately threatening vital ecosystem services. Among the ocean-based NETsartificial ocean alkalinization via the dissolution of Ca(OH)2, known in short as ocean liming, has attracted attention due to its capability of contemporarily addressing two issues: global warming via increased levels of CO2 and ocean acidification.

A new study recently published in Frontiers in Climate exploresthe case of ocean alkalinization in detail. The research, realized by the Euro-Mediterranean Center on Climate Change Foundation (CMCC) and the Politecnico di Milano within the Desarc-Maresanus project, with the financial support of Amundi and the collaboration of CO2APPS, presents an analysis of marine alkalinization applied to the Mediterranean Sea taking into consideration the regional characteristics of the basin. Researchers used a set of simulations of alkalinization based on current shipping routes to quantitatively assess the alkalinization efficiency via a coupled physical-biogeochemical high-resolution model (NEMO-BFM) for the Mediterranean Sea (1/16° horizontal resolution that is ~6 km) under an RCP4.5 scenario over the next decades. The alkalinization strategies applied in this study to the Mediterranean Sea illustrate the potential of ocean alkalinization to mitigate climate change by increasing the air-sea flux of CO2 across the basin and counteracting acidification. In contrast to previous studies, the analyzed scenarios offer a clear pathway into practical implementation being based on realistic levels of lime discharge using the current network of cargo and tanker shipping routes across the Mediterranean Sea.

Two different approaches of alkalinization scenarios have been explored: one with a constant annual discharge of lime over the entire scenario period and another with gradually increasing alkalinization levels proportional to the pH decreases in the baseline scenario RCP4.5. The simulations used in the study suggest the potential of nearly doubling the carbon-dioxide uptake rate of the Mediterranean Sea after 30 years of alkalinization, and of neutralizing the mean surface acidification trend of the baseline scenario without alkalinization over the same time span.

A more recent paper carried out within the project and just published, realizes an estimate of the potential of maritime transport for ocean liming and atmospheric COremoval, highlighting a very high potential discharge of slaked lime in the sea by using the existing global commercial fleet of bulk carrier and container ships. For some closed basins, such as the Mediterranean Sea where traffic density is relatively high, the potential of ocean alkalinization, also with low discharge rates, is far higher than what is needed for counteracting ocean acidification. Therefore, the results of this study highlight from one hand the need for further research for a more precise assessment of the technical aspects of this approach and potential criticalities, from another hand indicates the potential of a regional implementation of ocean liming to the Mediterranean Sea based on the existing network of tankers and cargo ships.

“These two publications provide a key contribution to the international and national scientific and technical communities working to find solutions to these two issues – atmospheric CO2 removal and counteracting ocean acidification – which we will have to tackle in the future. Even if further investigations are needed, these results are encouraging”, states Stefano Caserini, Professor of Mitigation of Climate Change at Politecnico di Milano and Project leader of the project Desarc-Maresanus.

“In these works the idea of ocean alkalinisation as a mitigation strategy for climate change is for the first time assessed on the base of a technically feasible pathway of implementation providing a first step towards a real-world application. In addition, even if the full ecological consequences of this strategy still require additional research, a solution is indicated that may stabilise the acidity of the seawater counteracting acidification without risking dramatic alterations of the seawater chemistry in the opposite direction, which as of today would have largely unknown consequences.” states the main author of the first article, Momme Butenschön, Lead Scientist of the Research Unit on Earth System Modelling at the CMCC Foundation Euro-Mediterranean Center on Climate Change (CMCC).

Read the full papers published in Frontiers in Climate:

Butenschön M., Lovato T., Masina S., Caserini S., Grosso M. (2021), Alkalinization Scenarios in the Mediterranean Sea for Efficient Removal of Atmospheric CO2 and the Mitigation of Ocean AcidificationFrontiers in Climate – Negative Emission Technologies, volume 3, 11 pages, DOI: 10.3389/fclim.2021.614537

Caserini S., Pagano D., Campo F., Abbá A., De Marco S., Righi D., Renforth P., Grosso M. (2021) Potential of maritime transport for ocean liming and atmospheric CO2 removalFrontiers in Climate – Negative Emission Technologies. 3:575900.


Continue reading ‘Reducing ocean acidification by removing CO2: two targets for cutting-edge research’

Biological impacts of ocean warming, acidification, and deoxygenation on the marine biota (text & video)

CEBIMário apresentado no dia 13/05/2021 por Dr. Rui Rosa (Universidade de Lisboa)

The global ocean has been shielding our planet from abrupt climate change, by absorbing a large portion of the anthropogenically emitted carbon dioxide and the excess heat trapped in the atmosphere, leading to ocean acidification and warming. Additionally, oxygen loss in the ocean (also known as deoxygenation) is being exacerbated by the global rising temperatures. This complex 3-way interaction (“deadly trio”) will definitely shape populations’ fitness and ecosystems’ health in the ocean of tomorrow. Here I will discuss that ocean deoxygenation effects may be greater than those caused by acidification and warming, and that they are consistent across different levels of biological organization, taxonomic groups, ontogenetic stages, and climate regions.

Host: Juan Pablo Quimbayo (CEBIMar/USP) –

Rui Rosa (Universidade de Lisboa) –

Continue reading ‘Biological impacts of ocean warming, acidification, and deoxygenation on the marine biota (text & video)’

Scientists find underwater plants can combat ocean acidification

An underwater view of a seagrass meadow with the sunlight shining through the surface waters and illuminating the seagrass blades..
Seagrass is an underwater plant. Like land plants, seagrasses need light and carbon dioxide to perform photosynthesis. GETTY

Human-generated carbon emissions are causing the world’s oceans to become more acidic. Since the start of the industrial revolution, when mankind’s emissions began ramping up, the world’s oceans have already become about 30% more acidic. For shell-building animals in particular, like oysters and snails, ocean acidification’s impacts can be devastating.

Marine scientists have suspected for years that underwater plants and seaweeds could combat the effects of ocean acidification on marine life. Now, research recently published in the journal Global Change Biology provides the most compelling evidence yet that underwater grasslands may create safe zones for marine life vulnerable to ocean acidification’s destructive effects.

Continue reading ‘Scientists find underwater plants can combat ocean acidification’

A critical analysis of the ocean effects of carbon dioxide removal via direct air and ocean capture – is it a safe and sustainable solution?

Executive Summary

Catalyzed by the 2015 Paris Agreement, there are numerous initiatives for policies and sciencebased solutions to reduce greenhouse gas emissions and to achieve net-zero emissions internationally. President Biden plans to achieve net-zero in the United States no later than 2050. Despite forward-moving initiatives, the Intergovernmental Panel on Climate Change (IPCC) recently reported that two-thirds of the countries that have pledged to reduce greenhouse gas emissions have committed to levels that remain insufficient in meeting vital international climate targets [1]. The overarching goal to reduce greenhouse gas (GHG) emissions must be accomplished by transitioning to a more equitable and environmentally just energy system that reduces pollution while meeting global food, transportation, and energy needs. Carbon dioxide removal (CDR) is at the forefront of policy change, investments, and technology to reduce the amount of CO2 in the atmosphere and the ocean. We must respond quickly, yet carefully, to the considerable pressure to remove carbon dioxide from the atmosphere even as we transition away from burning fossil fuels and other anthropogenic CO2-emitting activities. There are a number of emerging technologies based on direct air capture (DAC) and direct ocean capture (DOC) which use machines to extract CO2 directly from the atmosphere or the ocean and move the CO2 underground to storage facilities or utilize the CO2 to enhance oil recovery from commercially-depleted wells. These technological interventions are in contrast to nature-based solutions. These include restoring mangroves and other coastal and marine ecosystems, regenerative agriculture, and reforestation to remove and store carbon dioxide in plants and soils. These nature-based strategies can offer multiple community benefits, biodiversity benefits, and long-term carbon storage, a global benefit.2 This report mainly focuses on the viability and consequences, including potential harm to the environment and livelihoods of the direct air capture and direct ocean capture approaches.

Continue reading ‘A critical analysis of the ocean effects of carbon dioxide removal via direct air and ocean capture – is it a safe and sustainable solution?’

Stressing out reef life earns marine researcher a nod from the PM

Australian scientists said they have discovered a detached coral reef on the Great Barrier Reef that exceeds even the height of iconic buildings like the Empire State Building and the Eiffel Tower.

In tanks across the world, marine researcher Christopher Cornwall’s​ team deliberately stressed coral and algae species, by slowly making the water more acidic. The work, recreating what’s happening in our oceans because of climate change, earned him the Prime Minister’s emerging scientist prize.

Reefs – from the famous coral ecosystems to forests of kelp – are facing an uncertain future, said the Victoria University research fellow. Human-made greenhouse gas emissions are affecting the oceans in two ways.

The additional carbon dioxide in the air is absorbed by the ocean, affecting the pH balance of the water, which is slowly becoming more acidic. Species that surround themselves with calcium carbonate skeletons struggle to maintain a stable internal environment. It’s this effect that Cornwall is mimicking in his tanks.

Continue reading ‘Stressing out reef life earns marine researcher a nod from the PM’

GOA-ON webinar series: Canada’s ocean acidification community of practice

Wednesday, 21 April 2021 at 14:00 EDT (UTC -4)

Register here:

Dr. Kristina Barclay,
Coordinator, MEOPAR OA Community of Practice, Postdoctoral Associate, University of Calgary, Canada

Webinar description: The MEOPAR OA Community of Practice (CoP) was formed in 2018, with the overarching goal of sharing knowledge and improving linkages between OA knowledge creators and end-users across Canada. The OA CoP is led by two Co-Leads, Dr. Helen Gurney-Smith (DFO) and Dr. Brent Else (University of Calgary), and a Coordinator, Dr. Kristina Barclay (University of Calgary, MEOPAR), with guidance from an interdisciplinary Steering Committee from across the country. OA CoP objectives include the development of: knowledge transfer and community engagement via accessible content, resources, and databases, and best-practices for data collection and sharing involving research groups, stake-holders, and community-based research. In this webinar, Dr. Barclay will present some of the key activities to date, the new online resources and blog series, as well as updates on the development of future projects. Current and future activities are focused on increasing online content and resources to increase OA CoP awareness and engagement, the development of a low-cost OA sensor package to aid aquaculture operations and larger monitoring efforts, conducting regional vulnerability assessments, and participation in partner OA organizations, including the GOA-ON North American Hub, the OA Information Exchange, DFO-NOAA OA Working Groups, the OA Alliance, and MEOPAR.

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Ocean acidification in the IPCC AR5 WG II

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