Ocean Acidification

Our planet relies on the oceans as climate regulators. At the same time, the effects of our emissions are most evident in the oceans. Today, eutrophication, climate change, ocean acidification, and invasive species are some of the challenges the oceans face.

The Ocean – A key player in climate

The oceans are already significantly impacted by human activity, making them sensitive to further influence from climate change. Habitats of species may disappear, shift, or shrink, while others gain access to new distribution areas. This can lead to a reduction in biodiversity, exacerbating the oceans’ resilience against, for example, climate change.

According to the International Panel on Climate Change (IPCC), over 90 percent of excess heat and between 20 and 30 percent of carbon dioxide emissions have been absorbed by the oceans. Carbon dioxide is absorbed by the oceans as the gas dissolves in water, and phytoplankton in surface waters take it up and bind it in organic material through photosynthesis. Phytoplankton are then consumed by zooplankton, which, along with other organisms, fall towards the ocean floor as marine snow when they die. This process allows large amounts of carbon from the upper layers of the ocean to reach deeper layers which is crucial for the organisms there. The transport of carbon to the bottom also ensures that it remains in the oceans much longer than if it were to stay in the surface layer, potentially leaking carbon dioxide back into the atmosphere.

In the wake of two harsh winter storms, Bill Mook says the shellfish industry must further adapt to climate change, calls for greater mitigation efforts

Bill Mook sells about 4 million market-size oysters annually. To deal with potentially devastating winter storms, Bill Mook has built underground water tanks to protect his inventory. Photo by Clarke Canfield.

The one-two wallop of mid-January storms was an eye-opener to coastal business and property owners along Maine’s long jagged coast. Never before had they seen such widespread destruction and chaos brought on by environmental changes widely considered a result of climate change.

Bill Mook’s eyes, however, were already wide open to the long-term shifts of temperatures and weather patterns. His oyster-farming business has long withstood the impacts of rising sea levels, warming waters, more frequent and intense storms, ocean acidification, harmful bacterial outbreaks — all of which have forced him to adapt to what nature hurls his way.

Oysters form the foundation of a delicate ecosystem that’s threatened by ocean acidification.

• Oysters are a foundation species – they create habitats that benefit other organisms in an ecosystem.
• Oyster reefs can be worth billions of dollars in trade and due to their ability to protect our coastal ecosystems, and so initiatives to restore and conserve them are vital.
• But these molluscs are threatened by ocean acidification and so action is needed to address the root causes of climate change and to safeguard the delicate ecosystems oysters help to create and maintain.

In the intricate tapestry of coastal ecosystems, the threat of ocean acidification has emerged as a menacing force. It transcends boundaries, leaving a distressing yet still delible mark on many habitats and species, including oysters. This challenge threatens not only their existence, but the delicate ecosystems these molluscs support. Recent environmental conservation efforts show the benefits of oyster reef construction and how these often overlooked bivalves – molluscs with hinged, two-part shells – are pivotal to marine environments.

As ocean acidification intensifies, the future of the oyster hangs in the balance – and with it, environmental and economic ecosystems. Addressing this problem will require policymakers, industries and people around the world to comprehend the interconnectedness of our oceans and act accordingly.

(Photo credit: IAEA image bank)

In some of the same ways it is employed to unravel archeological mysteries, nuclear science is being used to understand climate-change impacts. Among these is a major problem threatening Latin America and the Caribbean—ocean acidification and the damage it is doing to marine life. Ocean acidification, a reduction in the ocean’s pH levels, is caused by seawater’s absorption of carbon dioxide (CO2) from the atmosphere. As ongoing human use of fossil fuels boosts CO2 concentrations in the air, greater amounts of the gas dissolve in seawater, making the oceans more acidic. Acidification of seawater has been found to affect corals, crustaceans, mollusks, and other marine life that is key to coastal ecosystems and communities in Latin America and the Caribbean. It does so by hampering the ability of marine animals to grow skeletons and shells, earning the nickname “osteoporosis of the sea.”

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Ocean acidification is being brought on by the atmosphere’s increasing carbon dioxide content. That is a process that poses a major threat to marine life and the entire oceanic ecosystem. Beyond that, it poses a significant danger to the health of our planet, Earth.

Understanding Ocean Acidification

As previously noted, ocean acidification is a natural phenomenon that results from CO2 absorption into the ocean. This happens when the CO2 combines with seawater. As a result, carbonic acid is produced. The pH of the ocean automatically decreases when carbonic acid levels rise. When the carbonic acid increases there is an automatic decline in the ocean’s pH level. What’s even more concerning is that since the rise of the Industrial Revolution, our oceans have absorbed roughly 30% of the CO2 released into the atmosphere. This absorbsion led to a profound shift, with the ocean’s acidity levels rising by a frightening 26%.

Impact on Marine Life

Many marine species are at danger of not surviving due to the severe effects of rising ocean acidity. Specifically those reliant on calcium carbonate to form their shells and skeletons. This encompasses corals, mollusks, and specific types of plankton. The highly acidic environment limits the availability of essential carbonate ions. Those are vital for these organisms to create and maintain their calcium carbonate structures. This could result in weakened shells, stunted growth, and even mortality. 

The rise in carbon dioxide levels in our atmosphere is also helping to acidify our oceans even further, resulting in more dire consequences for aquatic ecosystems and the planet. But, our wetlands may have the solution

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Scientists are looking for solutions to remove greenhouse gases trapped in our atmosphere, and one idea may lie in the wetlands.

Stopping fossil fuel emissions will not be enough to limit global warming to a 1.5°C to 2°C rise during this century, according to Kevin Kroeger, United States Geological Survey (USGS) research chemist.

Similar to how plants in wetlands and other landscapes work, oceans ingest carbon dioxide from the atmosphere directly, like a sponge, and that form of carbon is acidic. While that process can regulate the amount of CO2 in Earth’s atmosphere, the oceans then bear the brunt of the effects. The result sees significant and negative impacts on coral reefs, shellfish and other aquatic species.

Not every type of carbon is acidic, however. Some of it that transitions from wetlands to oceans is in the form of bicarbonate, which can help offset acidity, according to the USGS.

(USGS)

“We’ve been looking at coastal wetlands, salt marshes, mangroves and the carbon cycling in those ecosystems as one opportunity for removing greenhouse gases from the atmosphere,” Kroeger said in a recent interview with The Weather Network.

Did you know that our oceans play a vital role in the fight against climate change? As carbon storage takes an increasingly important role in climate change mitigation, the term blue carbon has been gaining prominence. But what exactly is it and what role does it play in the context of climate change?

What Is Blue Carbon?

Blue carbon refers to carbon captured by marine ecosystems. It is well known that carbon dioxide (CO2) is one of the most important greenhouse gasses (GHGs) and a main contributor to climate change. As the primary GHG emitted through human activities, reducing the concentration of CO2 in the atmosphere is paramount to slowing down climate change. While the most sustainable way to do this is by reducing our effective CO2 emissions, carbon storage plays an important role in removing the CO2 that has already been released into the atmosphere. 

Carbon storage, also referred to as carbon sequestration, describes the process by which carbon is removed from the atmosphere and stored in a so-called carbon pool. While this process can be imitated or enhanced through technology, it occurs in nature all the time – for example in our oceans and the coastal vegetation surrounding them. 

As money pours into companies promising to take greenhouse gasses out of the atmosphere, there’s a small but fast-growing sector of startups that want to leverage one of the world’s biggest carbon sinks to clean up humanity’s climate pollution: the ocean. For our series Reverse Course, Chris Bentley reports on some of the scientists and entrepreneurs developing ways to enhance the ocean’s natural ability to take carbon dioxide out of the atmosphere.

And, researchers at the Pacific Northwest National Lab are also looking into how native eelgrass could fight ocean acidification, and how algae could offset carbon emissions in the construction industry. Bentley tells us more.

Then, NPR’s Aya Batrawy shares the latest from the COP28 summit in Dubai.

Isaac Olson wonders why there is not a single visitor in sight at an aquarium’s ocean acidification exhibit. (Image credit: Shruthika Kandukuri)

Ocean acidification (OA) is one of the most imposing, yet still misunderstood, threats to our coasts. Even within aquariums, it can be hard to find detailed information about OA. This is a huge missed opportunity, especially as aquariums serve as one of the best places to not only educate people on marine issues, but also center issues in the affected communities. Indeed, the clock is ticking: OA is already becoming increasingly devastating ecologically, economically, and culturally. Yet, there is still an opportunity to mitigate much of the worst effects … if we act now. Thus, to enable equitable and sustainable change, it is vital to connect with people through OA communication that engages and empowers people to take action, especially in the most at-risk regions.

That’s why, as a class of 2022 Hollings Scholar, I worked with NOAA’s Ocean Acidification Program, the Aquarium Conservation Partnership, and the International Alliance to Combat Ocean Acidification on a project to address that knowledge gap. We created a suite of six StoryMaps intended for use in aquariums to educate, empower, and engage guests. Each StoryMap focuses on a different region in the NOAA Coastal Acidification Network (Alaska, the California Current, the Gulf of Mexico, the Southeast, the Mid-Atlantic, and the Northeast). Users can explore OA trends, impacts, and responses in their region, and learn how they can take action at both an individual and community level. The StoryMaps themselves are also highly adaptable for use by educators, community organizations, marine learning centers, and other groups: sections can be turned into interactive displays, sent out as virtual learning resources, and even uniquely individualized to increase community relevance. 

Explore this StoryMap for OA in Alaska, or check out our full collection of StoryMaps!

Just four countries globally have regions to have published dedicated plans for tackling the threat posed by increasing seawater acidity levels, with the US taking the lead, a report has found.

Governments in nine US regions, one Canadian province, Sweden, and the Netherlands have published ocean acidification action plans so far, a report by research initiative Back to Blue, has found.

Ocean acidification, which is the rising acidity of seawater caused by CO₂ emissions, poses a threat to communities and marine life. Around 30% of CO₂ released into the atmosphere annually is absorbed by the ocean, according to the report seen by Carbon Pulse.

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Ocean acidification is often dubbed as the evil twin of climate change, and rightly so. The ocean is the planet’s biggest carbon sink. Since we have started burning fossil fuels and started producing CO2, half of it has been absorbed by the ocean.

Carbon dioxide combines with seawater to produce carbonic acid. The reaction also leads to increased concentration of hydrogen ions in the water. These hydrogen ions increase the pH level of water, making it more acidic.

The average seawater is 30% more acidic than it was at the start of the industrial age. By the end of the century, the ocean’s pH levels could reach 7.8. At the start of the industrial revolution, the pH was 8.2.

Ocean acidification is a serious threat to seafood abundance, so much so that the United Nations Environment Program has declared it a threat to international food security. Carbon dioxide is increasing in the atmosphere at shocking rates, which in turn causes an increased amount of carbon in the world’s oceans. More carbon dioxide in oceans causes an increase in oceans’ acidity, contributing to less carbonate available for marine animals who need it to create their shells and skeletons, and overall has the potential for devastating impacts globally. One area where this acidification would be the most detrimental is the Gulf of Maine because of its geographical position and the influx of fresh, cold water into the gulf. According to the Natural Resources Defence Council, Maine is at high risk for economic harm due to ocean acidification because of the ocean acidifying soonest in this area and the fact that residents here rely on shellfish for their livelihoods. Maine’s marine resource economy depends on harvesting shelled animals including lobsters, oysters, urchins, and clams.

For generations, the people of Fiji have built their lives around the country’s rich coral reef ecosystems. The ocean provides sustenance, while the dazzling marine life brings tourists from around the world. But climate change is threatening this way of life. Sea level rise is forcing coastal villages to relocate, with many more in peril. More frequent natural disasters have taken lives and destroyed houses, crops and infrastructure. But there’s another effect of climate change that isn’t as easy to see — an insidious rising danger for the people of Fiji: ocean acidification.

“When it hits, it’s going to be catastrophic,” says Katy Soapi, coordinator of the Pacific Community Centre for Ocean Science at the science and development organisation SPC. Worse still, Dr Soapi says Fiji and the broader Pacific region aren’t watching the emerging threat closely enough. “We are definitely flying blind,” she says. Many Pacific Island nations have historically lacked the resources to monitor the scale of the problem in their own waters. But now Dr Soapi is helping to establish a network of scientists that will use novel methods to turn this around.

Ocean acidification, the “evil twin” of global warming, presents a stern challenge to food security, particularly for Southeast Asians.

Sweltering heat waves have blanketed Southeast Asia and other regions recently. One contributing factor has been record-breaking ocean temperatures. Oceans have thus far absorbed the brunt of global warming- trapping 93 per cent of excess heat in the biosphere. Ocean warming, along with overfishing, has already caused fish stock depletion by between 15 and 35 per cent over the past eight decades even as global populations grew from 2 to 8 billion.

Unfortunately, record ocean temperatures are not the only issue of concern. Ocean acidification, sometimes called the “evil twin” of climate warming, is another result of rising greenhouse gas emissions.

Ocean acidification refers to the drop in pH levels in seawater, which were on average 8.2 in the pre-industrial era. Since then, it has declined by 0.1 units. While this appears minute, because the pH scale is logarithmic, this actually represents a 30 per cent increase in acidity. Mid-range projections for 2100 is that ocean pH could decline by 0.3 to 0.4 units. This would be devastating for ocean biodiversity. As a comparison, a drop in blood pH in humans by 0.2-0.3 units could cause seizures, comas and even death.

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The research was separated into three phases: (1) designing the survey, (2) conducting surveys and focus group discussions in the field, and (3) continually analyzing the data.

With the assistance of Dr. Patrizia Ziveri, our Pier2Peer mentor, we partnered with Dr. Victoria Reyes from the Universitat Autonoma de Barcelona (UAB) and the Comanagement Association (CMA) in Robertsport to plan interviews and group discussions involving female fishers and traders. This project utilized a research protocol based on the LICCI project https://doi.org/10.1371/journal.pone.0279847.

Examining the involvement of women in fisheries will offer comprehensive insights into geolocalized community-based data concerning climate change and ocean acidification effects and resilience. This research study aims to investigate how local knowledge can assist in climate and ocean acidification research, enhance our comprehension of the perceived impacts of climate change and ocean acidification, and incorporate local knowledge into policymaking. The project will document and communicate climate change, and ocean acidification impacts at the local level, capturing how small-scale fisheries (SSF) have adapted to these impacts.

The study aims to pinpoint locally perceived species abundance, temporality, location, and size and evaluate how the fishing community has responded to these changes.

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One of the effects of global warming is the acidification of the oceans… the trend of our big bodies of salt water to get more acidic over time. Not enough that you’d notice it swimming or surfing, but enough to make it hard for some sea creatures with shells to form those shells in the first place.

The California Academy of Science is one of several institutions signing onto a letter proposing something like a checklist for governments to follow in preparing for acidification. The items on the list range from public awareness to mitigation measures.

There’s clearly some ground to cover: for example, coral bleaching, which is very well known, is not the same. Rebecca Albright is the California Academy’s Curator of Invertebrate Zoology and founder of the Coral Regeneration Lab (CoRL). She visits with some details of the ocean acidification framework.

The remote fishing village of St Abbs, Scotland, was made famous as the filming location of New Asgard in Marvel’s “Avengers” movies.

But to locals, it’s better known as a surfing and walking destination thanks to its sandy beaches and 200-acre nature reserve.

St Abbs is also home to a marine-research facility where scientists tackle an array of issues facing the ocean, with a focus on conservation.

Inside one of the facility’s labs are 40 small “future oceans” — tanks of seawater chemically altered to reflect potential future scenarios of the ocean impacted by climate change. 

The ocean has absorbed around 30% of the carbon dioxide produced since the industrial revolution, making it an invaluable tool in the fight against climate change.

But all this CO2 is changing the ocean’s chemistry, making it more acidic. Increased acidity could devastate marine ecosystems, which are built upon coral reefs, and in turn, affect the fish and seafood humans eat. 

The tanks, which hold dead and alive deep-sea coral, are part of a research project by the marine biologist Sebastian Hennige and Uwe Wolfram, a material scientist who focuses on bones.

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