Higher atmospheric carbon dioxide levels paired with melting ice are causing ocean acidity levels in the waters around Antarctica to rise rapidly. Credit: W. Bulach/Wikimedia Commons, CC BY-SA 4.0
Even the cold, remote waters of Antarctica are no refuge from ocean acidification. Acidity in some places in the ocean around Antarctica could double compared to 1990 levels by the end of the century, according to new research. Even if emissions don’t continue their steep rise, ocean acidity is likely to be significantly higher on the Antarctic shelf than it is today, threatening many of the organisms that live there.
A years-long study focused on the climate effects on coral reefs by California State University, Northridge marine biologists Peter Edmunds and Robert Carpenter reveals concerns for their future survival.
The new study, published in Limnology and Oceanography and led by Edmunds and Carpenter, who have more than 30 years of experience researching coral reefs, shows the long-term consequences of ocean acidification for coral reefs in Mo’orea, French Polynesia. Combined with rising seawater temperatures, the coral reef structures may not be able to grow and reproduce as climate change continues.
The four flumes that were used to complete the recently published study. The flumes were built with the help of the CSUN Science Shop and each is 5 m in length (~16 ft), and they are located at the UC Berkeley, Richard B. Gump research lab. Over the course of 3 years, they were used to complete year-long experiments in which replica coral reefs were built in each flume and incubated under conditions simulating future predicted levels of ocean acidification. Photo provided by Peter Edmunds.
Scientists are uncovering new insights into the dynamics of ocean acidification in coral reefs off the coast of Florida, including Molasses Reef in the Florida Keys. Credit: Matt Kieffer, CC BY-SA 2.0
Source: Global Biogeochemical Cycles
As carbon emissions increase, the ocean absorbs more carbon dioxide. This causes a chain of chemical reactions that results in the formation of carbonic acid and overall ocean acidification. The excess hydrogen ions associated with ocean acidification can threaten coral reefs in two ways: The ions can break up the calcium carbonate of which coral exoskeletons are made, and they can bond with carbonate ions, leaving less material for corals to build their exoskeletons in the first place.
At smaller scales in shallower areas, local variations in the chemistry of seawater may either exacerbate or mitigate the effects of ocean acidification on reefs. In particular, biological activity—such as photosynthesis by algae and seagrass, or respiration by animals and other organisms—may alter the carbonate chemistry and acidity of seawater.
Fishing nets churn up carbon from the sea floor, more than half of which will eventually be released into the atmosphere..
Scientists have long known that bottom trawling – the practice of dragging massive nets along the seabed to catch fish – churns up carbon from the sea floor. Now, for the first time, researchers have calculated just how much trawling releases into the atmosphere: 370m tonnes of planet-heating carbon dioxide a year – an amount, they say, that is “too big to ignore”.
Over the study period, 1996-2020, they estimated the total carbon dioxide released from trawling to the atmosphere to be 8.5 to 9.2bn tonnes. The scientists described trawling as “marine deforestation” that causes “irreparable harm” to the climate, society and wildlife.
The acidity of Antarctica’s coastal waters could double by the end of the century, threatening whales, penguins and hundreds of other species that inhabit the Southern Ocean, according to new CU Boulder research.
Scientists projected that by 2100, the upper 650 feet (200 meters) of the ocean—where much marine life resides—could see more than a 100% increase in acidity compared with 1990s levels. The paper, appeared Jan. 4 in the journal Nature Communications.
The oceans play an important role as a buffer against climate change by absorbing nearly 30% of the CO2 emitted worldwide. But as more CO2 dissolves in the oceans, the seawater becomes more acidic. “Human-caused CO2 emissions are at the heart of ocean acidification,” said Cara Nissen, the paper’s first author and a research scientist at INSTAAR.
The Southern Ocean, which surrounds Antarctica, is particularly susceptible to acidification, partly because colder water tends to absorb more CO2. Ocean currents in the area also contribute to the relatively acidic water conditions.
Cara Nissen
Using a computer model, Nissen, Lovenduski and the team simulated how the seawater of the Southern Ocean would change in the 21st century. They found it would become more acidic by 2100, and the situation would be severe if the world fails to cut emissions.
“It’s not just the top layer of the ocean. The entire water column of the coastal Southern Ocean, even at the bottom, could experience severe acidification,” Nissen said.
The team then investigated the conditions specifically in Antarctica’s marine protected areas (MPAs). Human activities, such as fishing, are restricted in these regions to protect biodiversity. Currently, there are two MPAs in the Southern Ocean, covering about 12% of water in the region. Scientists have proposed designating three more MPAs to an international council in the past years, which would encompass about 60% of the Antarctic Ocean.
The team’s model showed that both adopted and proposed MPAs would experience significant acidification by the end of the century.
For example, under the highest-emission scenario, where the world makes no efforts to cut emissions, the average acidity of the water in the Ross Sea region—the world’s largest MPA off the northern tip of Antarctica—would increase by 104% over 1990s levels by 2100. Under an intermediate emissions scenario, the water would still become 43% more acidic.
“It’s surprising to me how severe ocean acidification would be in these coastal waters,” Nissen said.
Previous studies have shown that phytoplankton, a group of algae that forms the basis of the marine food web, grow at a slower rate or die out when the water becomes too acidic. Acidic water also weakens the shells of organisms like sea snails and sea urchins. These changes could disrupt the food web, eventually impacting top predators like whales and penguins.
The Weddell Sea is one of the three proposed MPAs located off the coast of the Antarctic Peninsula. Nissen said scientists think the Weddell Sea region could act as a climate change sanctuary for organisms, mainly because this area has the highest levels of sea ice coverage in the Antarctic. The ice shields the ocean from warming and prevents the seawater underneath from absorbing CO2 from the air, thereby reducing the rate of acidification. In addition, the region has little human activity to date.
But the model suggested that as the planet continues to warm, the sea ice will melt, and the Weddell Sea region will experience acidification on par with other MPAs under intermediate to high emission scenarios, but with a slightly delayed progression.
“The result shows that establishing the Weddell Sea region as a protected area should have high priority,” Nissen said.
“As a scientist who typically studies the open ocean, I tend to think of Antarctic coastal areas as a conduit for climate signals to reach the global, deep ocean. This study reminded me that these dynamic Antarctic coastal areas are also themselves capable of rapid change,” Lovenduski said.
The study suggests that the world could only avoid severe ocean acidification of the Southern Ocean under the lowest emission scenario, where society cuts CO2 emissions quickly and aggressively.
“We still have time to select our emission pathway, but we don’t have much,” Nissen said.
Scientists recover the CTD, an instrument used to measure conductivity, temperature, and depth of the ocean on the back of the R/V F.G. Walton Smith in choppy weather during water sampling. Photo: Tyler Christian, Cooperative Institute for Marine and Atmospheric Studies.
Researchers studying South Florida’s coral reefs found that the region’s nearshore reefs and more sheltered inshore areas are less vulnerable to ocean acidification than previously thought – a major climate-related threat to coral reefs as ocean waters absorb more atmospheric CO2 from the burning of fossil fuels.
This new study, led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science offers a glimmer of hope for Florida’s iconic coral reefs as ocean acidification, along with marine heat waves and other climate-related threats are impacting coral reefs worldwide.
Brittany Jellison and marine biology graduate student Todd Stelling will first study if more acidic ocean water alters predator-prey behaviour in juvenile lobsters. (Photo: Alex Hatch)
Jellison and graduate student Todd Stelling are using a new experimental system at UNH’s Coastal Marine Lab (CML) that enables them to manipulate the chemistry of incoming ocean water. They then can determine how ocean acidification might affect lobster behaviour in response to cues, like the presence of prey.
“If the lobsters cannot locate their prey in a timely manner, it means longer time spent foraging, which leaves them vulnerable to predators. And decreased lobster survival rates will damage the coastal ecosystem and diminish a key fishery for New Hampshire and Maine,” said Stelling.
Coral islands support and extend legal maritime jurisdictions.
University of Sydney researchers have found 25 percent of Australia’s coral islands, land masses formed by reefs, currently face high to very high risk of being wiped out by climate change.
The findings, published in the latest edition of the journal Science of the Total Environment, identified that all of the 56 investigated Australian coral islands are exposed to some degree of climate risk but that three small, unvegetated coral islands in Western Australia, on Scott, Clerke and Imperieuse reefs, are the most vulnerable.
Lead researcher Dr Tommy Fellowes from the School of Geosciences said: “The fate of low-lying coral reef islands and their associated reef ecosystems hangs in the balance, threatened by the compounding effects of climate change – rising sea levels, warming oceans, intensifying storms and acidification.”
“We quantified the risks to Australia’s coral islands for the first time and our findings make clear the urgent need to address these threats and the vulnerable state of these islands.
Decade-long ocean warming that impacts ocean circulation, a decrease in oxygen levels that contributes to changes in salinification and nutrient supply, and ocean acidification are just some of the challenges the world’s oceans are facing.
In 1988, a comprehensive sustained ocean time-series of observations, called the Bermuda Atlantic Time-series Study (BATS), began at a site about 80 km southeast of the island of Bermuda. There, scientists take monthly samples of the physics, biology, and chemistry of the ocean’s surface and depths.
In a new paper published in Frontiers in Marine Science, researchers have now presented the latest findings from this monitoring effort.
Stressful childhoods can affect an individual’s adult years and influence future generations. Scientists at the University of California, Davis, found a similar pattern holds true for red abalone exposed as babies, and again as adults, to the stress of ocean acidification.
Their study, published in the journal Global Change Biology, found that the negative impacts of ocean acidification — a byproduct of carbon dioxide emissions — on red abalone can last within and across generations. Buffering against ocean acidification at crucial life stages can help ease these effects for captive- and commercially raised red abalone, while informing efforts to conserve wild abalone, the study said.
“For red abalone, if your parents were exposed to ocean acidification, it does impact your ability to handle stress,” said lead author Isabelle Neylan, a Ph.D. student at UC Davis Bodega Marine Laboratory when the study was conducted and currently a postdoctoral researcher at Louisiana State University. “It’s carrying over within that generation and on to the next generation.”
Understanding carbon transport can offer important information about a changing climate. For instance, it can help scientists measure ocean acidification or other threats increased carbon levels pose to aquatic ecosystems. But one major, and often overlooked, source of carbon in the marine environment is dissolved inorganic carbon (DIC), transported from land to ocean by streams and rivers.
An article published in Journal of Geophysical Research: Biogeosciences by John Harley and team examines, with greater spatial and temporal resolution than ever before, how DIC moves through the Southeast Alaska Drainage Basin—which spans a coastal region shaped by glaciers, heavy rainfall, and dense rainforest—into the Gulf of Alaska.
The researchers analyzed 2,455 watersheds throughout a rugged coastal region of Alaska, British Columbia, and the Yukon territory. These watersheds contain both large rivers and smaller streams and freshwater sources, including rainfall, snowmelt, and glacier melt.
The longest ocean time series of dissolved carbon dioxide in the Pacific — part of the “Keeling Curve of the ocean” — is revealed.
For the first time, scientists at UC San Diego’s Scripps Institution of Oceanography have published nearly four decades’ worth of dissolved carbon dioxide measurements from waters off Southern California. The measurements reveal a slight but consistent trend of ocean acidification, a process characterized by a decrease in the ocean’s pH over time due to its absorption of carbon dioxide (CO2) from the atmosphere.
Since the early 1980s, samples of ocean carbonate chemistry have been collected by the California Cooperative Oceanic Fisheries Investigations (CalCOFI) program, which was established in 1949 to investigate the collapse of the sardine population off California. In a new study, Scripps Oceanography researchers present 37 years of measurements from CalCOFI Line 90 Station 90 (station 90.90), a measuring site located 450 kilometers (280 miles) off the coast of San Diego. The team’s findings were published on Nov. 3 in Communications Earth & Environment, a journal affiliated with Nature.
The measurements from station 90.90 establish the oldest time series of direct inorganic carbon observations in the Pacific Ocean. While measurements at the station carry on to the present day, the study details quarterly measurements collected from 1984 to 2021, with a gap from 2002 to 2008 due to a lack of funding. Notably, the data show that the seawater at the study site is getting more acidic, with a measured decrease in pH of 0.0015 per year.
Published by Back to Blue, a new report Ocean Acidification: Time for Action calls on international government action to step up in a bid to prevent the worst case scenario from unfolding. It also criticises the majority of countries for ‘ocean blindness’, and failing to factor this issue into climate change adaptation and mitigation plans.
Currently, just 12 countries have in the world have ocean acidification action plans, yet if the problem is allowed to persist and become worse, some $400billion could be wiped off the global economy.
As oceans are allowed to become more acidic, a direct result of absorbing increasing amounts of carbon dioxide, the effect on marine life is unforgiving, including the creation of so-called ‘dead zones’, and the destruction of finely balanced ecosystems. In turn, this is a major threat to the survival of coastal communities, many of which have developed due to the abundant riches found under water, not least fisheries, meaning the livelihoods of vast swathes of people now hangs in the balance.
According to data, policy advice and research institution the OECD, globally some three billion people rely on oceans for their income. In the U.S., for example, almost half the national GDP is tied to counties that are coastal adjacent, and more than three-million jobs, or one-in-45, are directly dependent on resources within the sea or Great Lakes.
Courtesy Of Tacho According to a NOAA study, the most likely cause for the mass disappearance was starvation caused by a marine heatwave between 2018 and 2019.
When scientists estimated that more than 10 billion snow crab had disappeared from the Eastern Bering Sea between 2018 and 2021, industry stakeholders and fisheries scientists had several ideas about where they’d gone.
Some thought bycatch, disease, cannibalism, or crab fishing, while others believed it could be predation from other sea animals like Pacific cod.
But now, scientists say they’ve distinguished the most likely cause for the disappearance. The culprit is a marine heatwave between 2018 and 2019, according to a new study authored by a group of scientists with the National Oceanic and Atmospheric Administration.
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More carbon dioxide in the atmosphere means warmer temperatures, Litzow said, which is bad news for the cold-loving snow crab. And more greenhouse gasses also mean more acidic oceans, which can also be dangerous for some crab.
“Carbon dioxide that we release through fossil fuels is also taken up by the oceans and has the effect of reducing the pH of the ocean — it makes it more acidic,” Litzow explained. “Because crab use calcium carbonate in their exoskeleton, they’re vulnerable to that acidification because calcium carbonate dissolves more and more easily as pH goes down.”
The good news — at least for snow crab — is they’re not as sensitive to ocean acidification as other species.
Scientists from JCVI and Scripps aboard R/V Atlantis in the Pacific Ocean off the coast of Big Sur, California. Photo courtesy Robert Lampe.
Scientists at the J. Craig Venter Institute (JCVI) and Scripps Institution of Oceanography at the University of California San Diego have for the first time shown that increased acidification of ocean water in an upwelling region reduces the availability of iron for phytoplankton, thereby threatening to reduce overall phytoplankton productivity. Given that phytoplankton sit at the base of the oceanic food web, acidification is a concern to all life in these upwelling regions. Upwelling regions are among the most productive due to the concentration of nutrients brought from deep water, driven by coastal winds. Results for this study are published in the journal Nature Communications.
While discussing the impact of this research, lead author Robert Lampe, a graduate student at Scripps Oceanography and JCVI stated, “This study provides critical insight into how key organisms in this ecosystem may respond to future conditions. Our current projections for how organisms and biological processes will respond to climate change are still quite uncertain and this brings us a step closer towards understanding change in the ecosystem.”
Aboard the R/V Atlantis, a research vessel owned by the U.S. Navy and operated by Woods Hole Oceanographic Institution (WHOI), JCVI and Scripps scientists spent 32 days in the California Current, a cold-water Pacific Ocean Current that runs southward along the western coast of North America. The team began their experiments—to better understand how acidification affects marine microbial life—near Big Sur, California and moved progressively farther from shore, performing four experiments in total.
PMEL makes critical observations and conducts groundbreaking research to advance our knowledge of the global ocean and its interactions with the earth, atmosphere, ecosystems, and climate. Photo of PMEL Carbon Mooring in Kaneohe Bay by Rusty Brainard.
Fifty years ago, NOAA created a new environmental research laboratory in Seattle with an initial focus on water quality in Puget Sound, and environmental studies of the Gulf of Alaska and Bering Sea. Since then, the Pacific Marine Environmental Laboratory has evolved into one of the world’s leading ocean research institutes, specializing in observing ocean conditions from tsunamis to changes in climate and ocean chemistry with the aid of innovative instrumentation and measurement strategies often developed by the lab.
To recognize PMEL’s half-century of accomplishments, the journal Oceanography has published a special issue with 29 diverse articles which highlight the laboratory’s scientific work over the last five decades. The issue provides new perspectives on global and regional implications of ocean acidification and its biological impacts, the influence of El Nino-Southern Oscillation on global weather patterns, and the important role marine aerosols play in regulating climate.
“PMEL researchers and their collaborators not only have fundamentally reshaped the scientific understanding of so many aspects of our ocean, their research and explorations have sparked our imagination and fascination with the deep and all that we might learn about our planet,” said NOAA Administrator and former President of The Oceanography Society Rick Spinrad, Ph.D. “Year after year, PMEL scientists continue to inspire the next generation of scientists and researchers, while providing the nation with the priceless knowledge gained by their investigations.”
The acidification of the oceans caused by human activity is already altering the production of marine plankton shells in the Mediterranean Sea. This is the worrying conclusion of a study led by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB), which alerts of the impact the decrease in pH of the surface ocean has on the production of calcium carbonate by marine plankton, with negative consequences for marine ecosystems.
Credit: Photo: ICTA-UAB
The acidification of the oceans caused by human activity is already altering the production of marine plankton shells in the Mediterranean Sea. This is the worrying conclusion of a study led by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB), which alerts of the impact the decrease in pH of the surface ocean has on the production of calcium carbonate by marine plankton, with negative consequences for marine ecosystems.
Anthropogenic carbon dioxide (CO2) emissions have increased alarmingly in recent decades. Since the Industrial Revolution, about 25% of anthropogenic CO2 has entered the ocean, changing water chemistry and lowering pH, a phenomenon known as ocean acidification.
The acidification of the Earth’s oceans is expected to triple by 2100, and could lead to major impacts on biodiversity across U.S. coastlines.
With climbing atmospheric CO2, huge amounts of this gas are absorbed by the oceans, dissolving to form carbonic acid, making the waters more and more acidic. This affects a huge number of marine animals and plants alike, but its impact on fleshy seaweeds around the coast may have knock-on effects across the food web, and make our beaches much less pleasant, according to a new study published in the journal Current Biology.
“We found evidence that OA (ocean acidification) could make seaweeds more vulnerable to physical damage, which could come from storms or from grazing animals,” study author and marine sciences researcher at the University of Gothenburg in Sweden, Alexandra Kinnby, told Newsweek.
“If this vulnerability means that the amount of seaweed decreases significantly it could have effects on the entire coast. Seaweeds form the base of the near-shore food web, they provide food and shelter to many small organisms which are in turn food for larger species,” she said.
Summary: Ocean acidification will likely almost triple by the end of the century — a drastic environmental change that could impact important marine species like fleshy seaweeds, algae that grow vertically and promote biodiversity in more than a third of the world’s coastline. To get a better idea of how seaweeds might fare in a rapidly acidifying ocean, a team of marine scientists subjected a common fleshy seaweed species to the acidification levels expected by the end of the century. They report that increased acidification impacted the seaweed’s chemical balance, made both its structure and its tissues weaker, and reduced its overall chances of survival.
Ocean acidification will likely almost triple by the end of the century — a drastic environmental change that could impact important marine species like fleshy seaweeds, algae that grow vertically and promote biodiversity in more than a third of the world’s coastline. To get a better idea of how seaweeds might fare in a rapidly acidifying ocean, a team of Swedish marine scientists subjected a common fleshy seaweed species to the acidification levels expected by the end of the century. In a study publishing on September 24 in the journal Current Biology, they report that increased acidification impacted the seaweed’s chemical balance, made both its structure and its tissues weaker, and reduced its overall chances of survival.
“Climate change is resulting in unprecedented changes in terrestrial and aquatic ecosystems through the emission of greenhouse gases, including carbon dioxide,” write the authors, who are based at the University of Gothenburg and the KTH Royal Institute of Technology. “Almost a third of that CO2 is taken up by the ocean, which has profound effects on seaweeds.”
A new objective examination of almost a quarter-of-a-century of ocean acidification research shows that, despite challenges, experts in the field can have confidence in their research.
The University of Adelaide’s Professor Sean Connell from the Ecology and Evolutionary Biology unit led the study.
“In our field, the marine science community was galvanised by the demonstration of how ocean acidification impairs shell-building life, which has profound implications for life on the planet,” he said.
“It is an inescapable fact that ocean acidification does impose harmful effects on shell-building life.”
This field is transformational and one of the most studied single topics in marine science in recent times.
Like all scientific research, findings were subjected to intense scrutiny including how to reproduce early results. Early in the history of ocean acidification research, controversy erupted over a set of failures to reproduce its effects on key behaviours of tropical fish.
