New research out of the School of Public Policy shows how policymakers can help shellfisheries in Northern California and Oregon adapt to ocean acidification caused by climate change
Average ocean pH has declined by 30 percent since the industrial revolution, a process termed Ocean Acidification (OA), which has direct, negative impacts on coastal communities reliant on ocean industries such as fishing and shellfish-specific aquaculture.
New research by Erika Allen Wolters, assistant professor of political science, and Ana Spalding, associate professor of marine and coastal policy (currently based at the Smithsonian Tropical Research Institute in Panama), examines how existing U.S. State and Federal policies impact the ability of shellfish growers in California and Oregon to adapt to OA. The paper, published in Marine Policy and supported by the National Oceanic and Atmospheric Administration, also identifies areas of opportunity for policymakers to better support shellfish growers.
This research builds on previous studies by Wolters and Spalding on the adaptive capacity of shellfish growers in both California and Oregon; both of which were published in Ocean and Coastal Management.
Coastal communities in California, Oregon, and Washington, are uniquely vulnerable to OA. This is due to both socioeconomic reliance on marine resources, like shellfish farming, and, in many cases, their geographic positioning along OA “hot spots” where a confluence of global and local variables such as runoff, pollutants, and coastal upwelling push pH levels to relatively extreme lows compared to other regions.
OA directly affects oysters during their seedling stage. The ocean is absorbing more carbon dioxide than ever before, however a lower pH means there’s less calcium carbonate in the water, which shellfish rely on to build their essential shells. As acidity increases, shells become thinner and growth slows.
Paleo-locations of SST proxies and CaCO3 datasets for the PETM. Credit: Nature Geoscience (2024). DOI: 10.1038/s41561-024-01579-y
A research team led by Prof. Li Mingsong at Peking University has provided new insights into the Paleocene-Eocene Thermal Maximum (PETM) and its effects on ocean chemistry.
The study, titled “Coupled decline in ocean pH and carbonate saturation during the Palaeocene–Eocene Thermal Maximum,” published in Nature Geoscience reconstructs ocean acidification during this ancient climate event, offering parallels with current trends linked to human-driven CO2 emissions.
The Paleocene-Eocene Thermal Maximum (PETM), 56 million years ago, was a major carbon release event that resulted in rapid global warming and significant ocean acidification. This study highlights parallels with current climate change, emphasizing the need to understand past events to predict future impacts. The findings stress the urgency of addressing human-driven CO2 emissions to protect marine ecosystems, particularly in vulnerable regions like the Arctic.
Ocean acidification
The team used paleoclimate data assimilation (DA), integrating proxy data and Earth system model simulations to reconstruct ocean carbonate chemistry. Atmospheric CO2 rose dramatically from 890 ppm to 1980 ppm during the PETM. Acidification was most severe in high-latitude regions, similar to current trends in the Arctic, where aragonite saturation is declining.
The PETM was triggered by a massive carbon release, causing rapid warming and disrupting ecosystems. Ocean pH declined by 0.46 units, from 7.91 to 7.45, causing widespread disruptions to marine life. The ocean acidification led to the extinction of 30%–50% of benthic foraminifera and significant marine biodiversity loss.
Current CO2 emissions are rising faster than during the PETM, threatening marine ecosystems and emphasizing the need for urgent climate action.
More information: Mingsong Li et al, Coupled decline in ocean pH and carbonate saturation during the Palaeocene–Eocene Thermal Maximum, Nature Geoscience (2024). DOI: 10.1038/s41561-024-01579-y
Planktonic foraminifera are tiny marine organisms important for the ecosystem. In response to increasing ocean warming and acidification, they are migrating deeper in an effort to survive. Sonia Chaabane, Julien Sulpis
Planktonic foraminifera — single-celled organisms who live in seawater — are under threat from warming oceans, a press release from the Max Planck Society said. In tropical regions, the unprecedented conditions could lead to more extinctions.
“Our data shows that planktonic foraminifera, which play a crucial role in the ocean’s carbon cycle, are struggling to survive in a rapidly changing climate. These organisms are like sentinels, warning us of the drastic effects that warming and acidification have on marine ecosystems,” said lead author of the study Sonia Chaabane, a researcher at the Max Planck Institute for Chemistry and the European Centre for Research and Teaching in Environmental Geosciences (CEREGE), in the press release.
The international team of researchers from Germany, France, Japan, Spain and the Netherlands analyzed almost 200,000 datasets going back to 1910 to find out how planktic foraminifers responded to climate change.
The researchers found that many species of foraminifera are migrating toward the poles at rates as high as 10 kilometers a year to escape rising sea surface temperatures. The data also showed that some species are migrating deeper into the ocean in search of cooler waters.
Even with these adjustments, foraminifera populations have shrunk by a quarter in the past eight decades. Tropical species have been the most impacted due to their reproductive cycles being disrupted by the extreme warming in these regions.
Rising carbon dioxide levels in the ocean, coupled with ocean acidification, lower calcium carbonate formation. Foraminifera use calcium carbonate to build their shells. When plankton die, their empty shells sink to the seafloor, so less shell production means less carbon storage.
“Rising carbon dioxide emissions are provoking ocean warming and acidification, altering plankton habitats and threatening calcifying organisms, such as the planktonic foraminifera (PF). Whether the PF can cope with these unprecedented rates of environmental change, through lateral migrations and vertical displacements, is unresolved,” the authors of the study wrote.
Bioindicators such as foraminifera, rather than individual measurements, are likely to provide a better understanding of the complex interactions between ecosystems and climate, the press release said.
“In view of advancing climate change, researchers are faced with the question of adaptation strategies individual species of planktonic foraminifera will develop in the near future,” said Ralf Schiebel, head of micropaleontology group at the Max Planck Institute for Chemistry, in the press release.
The study, “Migrating is not enough for modern planktonic foraminifera in a changing ocean,” was published in the journal Nature.
“Our insights into the adaptation of foraminifera during the Anthropocene suggest that migration will not be enough to ensure survival. This underscores the urgent need for us to understand how the interplay of climate change, ocean acidification and other stressors will impact the survivability of large parts of the marine realm,” the scientists wrote in the study.
Measurements were taken in various different sea states during two trips on royal research ships. Daniel Ford, CC BY-NC-ND
The oceans play a pivotal role in drawing down atmospheric carbon dioxide (CO₂) and have so far acted as a brake on the full impact of climate change. Current estimates of the CO₂ from the atmosphere that disappears in the ocean, commonly referred to as the ocean CO₂ sink, suggests that around 25% of all human CO₂ emissions have been taken up by the oceans.
In our recent journal paper in Nature Geoscience, we show that a thin layer at the ocean surface called the “ocean skin,” a layer thinner than a human hair, increases this ocean CO₂ uptake by about 7%. That sounds like a small difference, but this additional uptake is equivalent to the CO₂ absorbed by the entire Amazon rainforest each year.
This long-term uptake of carbon into the ocean has negative implications for ocean health. It is slowly causing the acidification of the oceans—as sea water takes up more CO₂ it is altering the ocean chemistry and lowering its pH, and this cannot easily be reversed.
Since the 1990s, scientists have suggested that a cooler skin would enhance CO₂ uptake by the oceans. As such, estimates of CO₂ absorption that ignore this effect would be inaccurate.
Since then, the sea surface temperature researchers have shown that the ocean skin is slightly cooler than the waters just below. This surface skin is, on average, ~0.17°C cooler. A temperature change like this increases the concentration of CO₂ in this tiny sliver of water. This matters because it’s this water that is in direct contact with the atmosphere.
Because the exchange of CO₂ between the ocean and atmosphere is controlled by the concentration difference between the surface and the layer of water below, this cooler skin increases the absorption of CO₂ into the ocean.
European researchers confirmed these concentration-driven processes in 2007. They used equipment similar to a powerful microscope with a camera to visualize oxygen gas concentrations within these tiny layers in a laboratory. In recent years, the impact of the surface layer on global ocean carbon has been evaluated using theory, modeling and satellite-based observations, but until now, nobody had actually measured this effect in the sea.
To carry out our research, the European Space Agency helped us put specialist measurements on board two research ships taking part in the annual Atlantic Meridional Transect scientific cruises that each year hosts UK and international scientists.
The Triassic-Jurassic extinction was a very sudden event, researchers assert
Summary: The Triassic-Jurassic Extinction, 201.6 million years ago, has been considered by some to have been a fairly slow-burn event, driven by rising temperatures and ocean acidification. A new study says it was kicked off for the most part by volcanic winter.
201.6 million years ago, one of the Earth’s five great mass extinctions took place, when three-quarters of all living species suddenly disappeared. The wipeout coincided with massive volcanic eruptions that split apart Pangaea, a giant continent then comprising almost all the planet’s land. Millions of cubic miles of lava erupted over some 600,000 years, separating what are now the Americas, Europe and North Africa. It marked the end of the Triassic period and the beginning of the Jurassic, the period when dinosaurs arose to take the place of Triassic creatures and dominate the planet.
The exact mechanisms of the End Triassic Extinction have long been debated, but most prominent: Carbon dioxide surfaced by the eruptions built up over many millennia, raising temperatures to unsustainable levels for many creatures, and acidifying the oceans. But a new study says the opposite: cold, not warmth was the main culprit. The study presents evidence that instead of stretching over hundreds of thousands of years, the first pulses of lava that ended the Triassic were stupendous events lasting less than a century each. In this condensed time frame, sunlight-reflecting sulfate particles were spewed into the atmosphere, cooling the planet and freezing many of its inhabitants. Gradually rising temperatures in an environment that was hot to begin with — atmospheric carbon dioxide in the late Triassic was already three times today’s level — may have finished the job later on, but it was volcanic winters that did the most damage, say the researchers.
“Carbon dioxide and sulfates act not just in opposite ways, but opposite time frames,” said lead author Dennis Kent of the Columbia Climate School’s Lamont-Doherty Earth Observatory. “It takes a long time for carbon dioxide to build up and heat things, but the effect of sulfates is pretty much instant. It brings us into the realm of what humans can grasp. These events happened in the span of a lifetime.”
In the new study, Kent and colleagues correlated data from CAMP deposits in the mountains of Morocco, along Nova Scotia’s Bay of Fundy, and New Jersey’s Newark Basin. Their key evidence: the alignments of magnetic particles in the rocks that recorded the past drifting of Earth’s magnetic pole at the time of the eruptions. Due to a complex set of processes, this pole is offset from the planet’s unchanging axis of rotation — true north — and to boot, changes position by a few tenths of a degree each year. (The reason that compasses do not point exactly north.) Because of this phenomenon, magnetic particles in lavas that were emplaced within a few decades of each other will all point in the same direction, while ones emplaced, say, thousands of years later will point 20 or 30 degrees in a different direction.
What the researchers found was five successive initial CAMP lava pulses spread over about 40,000 years — each with the magnetic particles aligned in a single direction, indicating the lava pulse had emerged in less than 100 years, before drift of the magnetic pole could manifest itself. They say that these huge eruptions released so many sulfates so quickly that the sun was largely blocked out, causing temperatures to plunge. Unlike carbon dioxide, which hangs around for centuries, volcanic sulfate aerosols tend to rain out of the atmosphere within years, so resulting cold spells don’t last very long. But due to the rapidity and size of the eruptions, these volcanic winters were devastating. The researchers compared the CAMP series to sulfates from the 1783 eruption of Iceland’s Laki volcano, which caused widespread crop failures; just the initial CAMP pulses were hundreds of times greater, they say.
How climate change impacts contaminants in the sea
The ocean is warming, becoming more acidic, and losing oxygen – these are well-known effects of climate change. What has been less studied is how these changes are affecting contaminants in the seas. A new study titled “Impacts of Climate Change on the Transport, Fate, and Biogeochemistry of Contaminants in Coastal Marine Ecosystems” has investigated the interaction of trace elements with climate change. The findings have been published in the Nature journal Communications Earth & Environment.
Climate Events are Releasing More Contaminants
“We wanted to understand how trace elements are being affected by climate change – an area that has seen very little research so far,” explains Dr Rebecca Zitoun, marine chemist at GEOMAR Helmholtz Centre for Ocean Research Kiel and co-lead author of the study alongside her Croatian colleague Dr Saša Marcinek from the Ruđer Bošković Institute in Zagreb. “We examined both human-induced and natural sources.” Metals such as lead, mercury, and cadmium enter the oceans not only through human activities such as industry or fossil fuel burning. Natural sources are also changing due to climate change: rising sea levels, rivers overflowing or drying up, melting sea ice and glaciers – all these processes mobilise and increase contaminant flows.
The study summarises the findings of a working group of the UN Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) focusing on metal contaminants in the ocean. The working group was initiated by Dr Sylvia Sander, Professor of Marine Mineral Resources at GEOMAR and former head of the Marine Environmental Studies Laboratories at the International Atomic Energy Agency (IAEA) in Monaco. Christoph Völker from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) is also contributing from Germany.
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Trace Elements in Seawater are Sensitive to Climate Change
Climate changes, such as rising sea temperatures, ocean acidification, and oxygen depletion, impact trace elements in various ways.
Higher water temperatures increase the bioavailability and uptake of trace elements such as mercury by marine organisms. This happens because higher temperatures boost metabolism, reduce oxygen solubility, and increase gill ventilation, leading to more metals entering organisms and accumulating in their bodies.
As the ocean absorbs most of the carbon dioxide (CO2) released by humans, it becomes more acidic – the pH level drops. This increases the solubility and bioavailability of metals such as copper, zinc, or iron. The effect is particularly pronounced with copper, which is highly toxic to many marine organisms at higher concentrations.
Furthermore, the growing depletion of oxygen, especially in coastal zones and on the seabed, enhances the toxic effects of trace elements. This stresses organisms that live directly in or on the seabed, such as mussels, crabs, and other crustaceans.
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Helmholtz Centre For Ocean Research Kiel (GEOMAR) (via EurekAlert!), 9 October 2024. Press release.
Eelgrass and oysters are ecosystem building species that both have economic, ecological, and cultural importance in Maine. Eelgrass populates much of the soft-sediment coastal subtidal in the Northern Hemisphere, which is also where most of the world’s oysters are farmed. Eelgrass and oysters can co-occur in Casco Bay, for example.
When grown in co-culture, oysters and seagrass have may offset the negative effects of climate related stressors on one another. This phenomenon, known as phytoremediation, has been seen in other parings of mollusks and marine plants as well. This is likely because mollusks need calcium carbonate to build their shells, and marine plants can remove carbon dioxide from the water column. Because large amounts of carbon dioxide can inhibit the production of calcium carbonate, marine plants can, in theory and in practice, increase shell growth in mollusks and other calcifying organisms.
Global ocean change, including rising sea temperatures and decreasing pH, will likely impact the interactions between eelgrass and oysters. As ocean temperatures increase, coastal waters are becoming simultaneously more favorable for raising oysters and less favorable for the health and survival of eelgrass meadows. The effects of the decline of eelgrass meadows and the benefits they provide to oysters and other organisms are currently unknown.
In this study, we sought to explore the impact of ocean change on this interesting relationship.
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The How:
We grew Eastern oysters (Crassostrea virginica) and eelgrass (Zostera marina) together or independently in a manipulated system. We raised our subjects in seawater-filled bucket-based mesocosms. We simulated ocean conditions in coastal Maine in the year 2100 by heating or bubbling CO2 into the seawater. We spent our summer monitoring the mesocosms, cleaning the buckets, and taking weekly pH and temperature measurements. At the end of the summer, we collected various eelgrass and oyster growth metrics including shoot length, shoot density, belowground biomass, and condition index.
Researchers maintaining outdoor seawater experimental tanks, growing seagrass and oysters under different ocean warming and acidification scenarios. Left to Right: David Carlon, Justin Baumann, Eban Charles, and Fiona Ralph. Photo by K. Dubois.
Close up of juvenile oysters growing attached to tiles and embedded within seagrass planted in an experimental bucket. Photo by K. DuBois.
The What:
The facilitative relationship between oysters and eelgrass that exists under ambient (current) conditions became muddled under future conditions (higher temperature and lower pH). We saw that in ambient conditions both partners benefitted from co-culture, but when any future ocean stressor was added, that positive interaction was lost or possibly even reversed.
Under ambient conditions, oyster presence increased eelgrass leaf growth by 35% and clonal reproduction (a way of measuring changes in meadow density) by 38%. Oysters exposed to eelgrass in ambient conditions saw decreases in the Oyster Condition Index: they were devoting more energy to shell growth than tissue growth.
Under future ocean conditions with higher temperatures and lower pH, oysters’ positive impact on eelgrass growth disappeared. In these same conditions, oysters saw an increase in Oyster Condition Index by 36%, meaning they spent more energy building up their tissue.
These findings illustrate how susceptible species interactions are to global environmental change. In many cases such as this one, the impacts of warming and acidification can compound on one another to alter these relationships.
Coral reefs are expected to continue facing severe heat stress as rising temperatures cause the oceans to warm excessively. However, new research suggests that modifying coral feeding habits could help local populations avoid complete extinction.
A study focusing on two coral species native to Hawaii revealed that warmer waters, a result of climate change, are a major factor in coral bleaching – a process that leads to a loss of color in coral, significantly harming their health and growth.
The researchers also examined the effects of ocean acidification on heat-stressed corals. Ocean acidification occurs when seawater absorbs excess carbon dioxide and becomes more acidic.
Coral exposure to heat stress
Over the last decade, mass coral bleaching events have increased in both frequency and severity, leading to higher mortality rates among coral populations worldwide.
Study lead author Kerri Dobson completed the research as a graduate student in earth sciences at Ohio State University. She noted that this study offers hope by suggesting that some coral species may be more resilient to these extreme environmental changes.
The eight most common species of coral around the islands can adapt to ocean warming and acidification but only if efforts to cut carbon emissions are made, according to a new study by researchers at the University of Hawaiʻi at Mānoa Hawaiʻi Institute of Marine Biology (HIMB).
Throughout the Indo-Pacific, a region that comprises more than two-thirds of the coral reefs on Earth, corals were found to be capable of surviving a “low climate change scenario,” where laboratory conditions reflect a global reduction in carbon dioxide emissions. Critically, none of the species in the study could withstand a scenario where carbon emissions were not reduced. The study published in Proceedings of the Royal Society Bsuggests that curtailing carbon dioxide emissions is essential for the survival of coral reefs.
“This study shows that widespread and diverse coral species all exhibit the potential to adapt to the changing climate, but climate change mitigation is essential for them to have a chance at adaptation,” said Christopher Jury, who is an HIMB post-doctoral researcher and lead author of the study.
Massive reef structures are formed over time. Growth is gradual; some coral colonies grow less than an inch each year, and researchers use coral growth rate as an indicator of reef ecosystem health. For nearly one year, the research team simulated realistic field conditions. They controlled levels of temperature and acidity, and measured the calcification responses of the eight species of coral.
“When we analyzed how the corals performed under warmer, more acidic conditions, we found that about one quarter to one half of their tolerance is inherited through their genes,” said Robert Toonen, research professor at HIMB and principal investigator of the project. “That means the ability to survive under future ocean conditions can be passed along to future generations, allowing corals to adapt to ocean warming and acidification.”
“This was a very surprising result, given the usual projected collapse of coral reefs in Hawai‘i and globally under these climate change stressors,” said Jury. “Most projections are that corals will be almost entirely wiped out, and coral reefs will collapse within the next few decades because corals cannot adapt fast enough to make a meaningful difference. This study shows that is not true, and we still have an opportunity to preserve coral reefs.”
The ability for corals to adapt to combined warming and acidification will play a key role in their responses to global change over coming decades. Most studies examining their ability to adapt have focused on heat tolerance. Far less is known about corals’ capacity to adapt to more acidic conditions, and very few studies have examined their capacity to adapt to the combination of warming and acidification. Evidence indicates they may be better at adapting to the changing climate.
“By understanding how these species respond to climate change, we have a better understanding of how Hawaiian reefs will change over time and how to better allocate resources as well as plan for the future,” said Jury.
Funding was provided by the National Science Foundation, UH Sea Grant College Program, and the National Oceanic and Atmospheric Administration’s Ocean Acidification Program.
A first of its kind Planetary Health Check by an international team of scientists indicates that six of nine planetary boundaries are not only transgressed, but are moving further into zones of risk. In addition, recent research shows that a seventh boundary, ocean acidification, is on the verge of transgression.
Intensifying ocean acidification spells problems for marine life, fisheries and economies. Based on current human CO₂ emission trajectories, this boundary may be breached in a few years, say experts. Others argue this threshold may already have been crossed, with regional acidification above safe limits.
Together, the nine planetary boundaries identify limits within which Earth systems can operate safely to maintain the planet’s habitability. Transgressing boundaries heightens risks of breaching tipping points that would bring about irreversible shifts to the planet, threatening humanity and life as we know it.
This inaugural Planetary Health Check is the first of yearly scheduled reports on the wellbeing of Earth systems. Annual reports are now needed due to humanity’s rapid crossing of planetary boundaries, and due to the urgency of providing up to date scientific data to policymakers.
The first ever pulse check of the planet’s health shows that the Earth is far beyond it’s safe operating space for humanity. Six of nine key planetary boundaries are already transgressed, and continue moving deeper into risk zones that could threaten our planet’s habitability. A seventh boundary, ocean acidification, is on the verge of transgression and may exceed safe limits in a matter of years.
Boundaries for climate change, biosphere integrity, land system change, freshwater change, biogeochemical flows, and the introduction of novel entities (such as synthetic chemical pollutants) are all surpassed, as a study published last year found.
Worryingly, in this latest report, all those already transgressed are moving deeper into the red zone, says Levke Caesar, a report author and co-leader on planetary boundaries at the Potsdam Institute for Climate Impact. “Our updated diagnosis shows that vital organs of the Earth system are weakening, leading to a loss of resilience, and rising risks of crossing [irreversible] tipping points.
“We see it’s not changing [for the better]. It is actually getting worse,” she says.
The breach of planetary boundaries heightens the risk of permanently damaging Earth’s life support functions, with the report warning that the world is entering a “dangerous new era.” Symptoms of boundary transgression already being seen include the rapid extinction of species, extreme heat, drought and storms, record wildfires, reduced crop and fisheries productivity, and freshwater scarcity.
“We are really risking losing the planet as we know it, and this risk is increasing the further we go into the red zones,” Caesar adds.
Worse still, the health check found that the ocean acidification boundary is nearing transgression, and may pass its global “safe operating space” threshold in the next few years, says Caesar. Acidification — driven by climate change-fueling CO2 emissions — could severely impact marine ecosystems and the global economy.
Graphic showing that six of the nine planetary boundaries have already transgressed the “safe operating space for humanity,” with ocean acidification on the verge of entering the red zone. Stratospheric ozone depletion is considered stable, while only atmospheric aerosol loading is trending in a positive direction. Image from Planetary Health Check 2024, designed by Globaïa.
Ocean health on the brink
For now, the ocean acidification boundary remains within the green safe operating space, according to scientists, but it is on the precipice. Studies show rising acidification could devastate fragile coral reefs and phytoplankton populations, considered the foundation of marine food webs. As acidification accelerates, global fisheries could degrade and even collapse, deepening human suffering and worsening hunger in vulnerable communities, and inflicting billions of dollars in global costs to economies.
Ocean acidification is driven by the same cause as climate change: rising atmospheric CO2 concentrations due to rampant fossil fuel emissions. The outlook for staying within the safe limit for this boundary appears bleak. “Looking at the current evolution, I’d say it’s really, really difficult to prevent that [boundary] crossing,” Caesar says.
The report uses surface aragonite saturation as an indicator for ocean acidification because it correlates to carbonate ion concentration. As atmospheric carbon dioxide is absorbed by the ocean, more-and-more carbonic acid is created, which releases hydrogen ions to lower pH and aragonite saturation. Declining pH in seawater means more ocean acidity and spells trouble for marine life that relies on calcium carbonate for shell formation.
The current safe operating limit is set at 2.75 aragonite saturation and is based on pre-industrial levels of 3.44. Levels below 3 can lead to some marine organisms becoming stressed, and if levels drop below 1 shells can begin to dissolve. Today, global aragonite saturation stands at 2.80. Passing that safe limit does not mean an immediate drop off a cliff, explains Caesar, but problems for marine life and the ocean’s food web will “definitely start to look more and more severe.”
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Report: Caesar, L., Sakschewski, B., Andersen, L S., Beringer, T., Braun, J., Dennis, D., Gerten, D., Heilemann,. A., Kaiser, J., Kitzmann, N.H., Loriani, S., Lucht., W Ludescher, J., Martin, M., Mathesius, S., Paolucci, A., te Wierik, S., & Rockström, J. (2024), Planetary Health Check Report 2024. Potsdam Institute for Climate Impact Research, Potsdam, Germany.
Ph.D. candidate Abigail Sisti works in the Seawater Research Lab at VIMS. Credit: Brittany Jellison
According to a study by researchers at William & Mary’s Batten School of Coastal & Marine Sciences, the American lobster may be more resilient to the effects of climate change than expected. For the first time, experiments performed at the Virginia Institute of Marine Science (VIMS) have documented how female American lobsters groom their offspring, providing evidence that these behaviors are not significantly impacted by temperature and acidity levels forecasted for Maine’s coastal waters by the end of the century.
The findings are published in the journal Marine Ecology Progress Series.
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“Brood grooming by female lobsters has been anecdotally observed, but it had not been quantitatively recorded before,” said Abigail Sisti, who is completing her Ph.D. in Marine Science at the Batten School and is lead author on the study. “In other crustaceans, these behaviors can have a significant impact on the survival of their offspring. Because the environment supporting the lobster fishery is rapidly changing, we wanted to understand how it might impact the way they care for their offspring.”
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The study was part of a larger effort to determine how multiple stressors affect the reproductive success of the species. In this study, the researchers were testing whether increases in water temperatures and acidity had an impact on grooming behaviors and embryo survival.
“The long-term nature of this experiment required somewhat of a moonshot approach,” said Rivest, whose seawater aquarium laboratory at VIMS has been specifically designed to control multiple environmental variables over long periods of time. “The conditions of our control group were set to match current conditions in the Gulf of Maine, while our experimental groups corresponded to temperature and pH predictions for the end of the century.”
In addition to their research outcomes, Sisti and others produced an educational curriculum to involve students and teachers in the research. The research as well as the lesson plans are documented through a story map produced by the National Oceanic and Atmospheric Administration’s Sea Grant and Ocean Acidification Program.
Documenting grooming behavior
The researchers partnered with officials from Maine’s Department of Marine Resources to secure lobsters from commercial operations for use in the study. They obtained female lobsters at a marketable size with intact legs, which are frequently lost in the wild or when they are caught. In total, they observed the behavior of 24 lobsters for five months, or until the embryos matured. Sisti and other students had the daunting task of reviewing dozens of hours of recordings from underwater cameras and documenting the frequency and type of grooming behaviors as well as the overall survival of the embryos.
Lobsters in experimental groups experienced temperature increases of 4 degrees Celsius and acidification levels of -0.5 pH from present conditions. Oxygen levels remained constant for all animals to isolate the effects of temperature and acidity.
A newly published study also provides ocean acidification maps. Credit: doi:10.1038/s41597-024-03530-7
Researchers from NOAA have produced a new online dashboard on the National Marine Ecosystem Status website that shows how ocean acidification is impacting eleven different marine ecosystems in the U.S.
These graphs, charts and mapped products, which were also described in a recent paper for Nature Scientific Data, provide a resource to fisheries and natural resource managers and deliver simple snapshots of ecosystem status with respect to ocean acidification.
“The dashboard provides regional context for anyone who wants to know how ocean acidification is progressing in U.S. coastal ecosystems,” said Dr. Jon Sharp, who led the work.
Sand sample from Elafonisos, Greece, with abundant A. lobifera shells, as well as shells and shell fragments from snails and other organisms. Credit: Olga Koukousioura
Pamela Hallock, a biogeological oceanographer and distinguished university professor at the University of South Florida College of Marine Science, typically finds little comfort in climate change.
Hallock has spent her career studying the ocean. She leads USF’s Reef Indicators Lab and is no stranger to the impacts of human activities on marine environments.
“These forams have been increasing in numbers in suitable environments,” Hallock said. “Now they’re so prolific that they’re becoming an economic resource in regions with warm waters and high alkalinity because they’re building beaches.”
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Amphistegina lobifera. Credit: Olga Koukousioura
“The rate at which these forams are building beaches in the region is comparable to the rate of sea level rise,” Hallock said.
There’s reason to believe A. lobifera may continue to flourish in a warming world replete with atmospheric CO2. The genus Amphistegina emerged on Earth during a period of higher atmospheric CO2 concentrations, Hallock noted in her paper, and warm waters with elevated alkalinity increase their rates of metabolism and shell formation.
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The recent study offers a unique perspective about the impacts of humans on marine environments, and vice versa.
As Hallock and her co-authors state in the study, “Might this return of prolific shallow-water carbonate production ultimately prove at least locally beneficial as climate change progresses?”
Immersive environmental ‘Sketches of Sensorium’ are being screened at the AlloSphere at UCSB
I’m coasting along the ripples on the surface of the ocean and dive below, swimming through coral reefs and passing schools of fish. When I look up I can see the sun reflecting on the surface of the water, below me the sandy ocean floor and behind me the reef surrounds me.
But…I’m bone dry – because I’m doing all this…on dry land!
This is the AlloSphere. It’s a three-story metal sphere in an echo-free chamber. Think the Las Vegas Sphere but on a smaller scale.
Inside, screens fill my vision all around, as I am led on this immersive deep-sea dive by JoAnn Kuchera-Morin, the AlloSphere’s Director and a Professor of Media Arts and Technology.
“It’s where you can have a group of researchers, a group of people come in and actually experience virtual reality in a new and different way as a group user experience instead of putting a helmet on your head. You’re actually here in the space and we can bring in any space that you’d like to be in,” said Kuchera-Morin.
The AlloSphere will host a series of public screenings of Sketches of Sensorium – immersive films which seek to answer a question.
“What are the implications of what’s happening with climate change and ocean health?” said Kuchera-Morin. “And so what Sketches does is in the beginning you were looking at the earth and we were out from afar. And we have actually NASA’s science data on that earth that will show you temperature change, show you ocean acidification, and then we’ll zoom in to certain places in the ocean to show the ramifications of what’s happening.”
As well as the awe inspiring visuals, the immersive sounds of ship engine noises and other ocean sounds takes your senses to the environment it seeks to protect.
“Think about how we live on the planet. We use all of our senses in order to navigate through complex systems. All of our senses vibrate in frequency relationships. So we have an infrasound across between feeling and hearing,” said Kuchera-Morin.
There’s a sweet spot where art and science meet. And that’s right here, says Kuchera-Morin, in this innovative space which started as an educational tool and is now challenging visitors into new thinking, insight and action.
“We do research with our scientists, but it’s education among us, but it’s also education that anyone can start to understand. And that’s the whole idea of the AlloSphere, where if we can bring data up to human scale and we can work with that data and we can understand it in a way that you’re not going to get from reading a science paper or a textbook,” said Kuchera-Morin.
“We may find a different way to educate. These are the classrooms of the future, the immersive cinemas of the future, the interactive situations of the future. And as media artist, it’s all to be able to do the most important things that we believe are really important in this world. That’s compassion, that’s understanding one another, that’s equity, and that’s climate justice,” she said.
The Sketches of Sensorium at the Allosphere at UC Santa Barbara is open to the public on six Thursdays and Saturdays starting Thursday 12 September, and you need tosign up online in advance.
Rainfall on the ocean’s surface is responsible for around 6% of the ocean’s uptake of carbon dioxide. Credit: Miguel Alcantara.
The ocean plays an important role in the global carbon cycle by absorbing about one-quarter of the carbon emitted by human activities every year. A study published recently in Nature Geoscience and co-authored by a University of Hawai‘i at Mānoa oceanographer revealed about 6% of the total uptake of carbon dioxide (CO2) by the ocean is due to rainfall.
“The impact of rain on air-sea CO₂ fluxes hasn’t been systematically examined, but understanding it gives us a more complete picture,” said David Ho, study co-author and oceanography professor in the UH Mānoa School of Ocean and Earth Science and Technology. “This is especially important since rainfall patterns over the ocean are expected to shift with climate change, and that could impact the ocean carbon sink.”
Exchanges between the ocean and the atmosphere are governed by various chemical, physical, and biological properties and processes. Rainfall alters these properties of the ocean surface, and thus promotes the exchange of CO2 at the air-sea interface.
Rain impacts this carbon exchange in three different ways. First, as it falls on the ocean surface, it generates turbulence that facilitates the renewal of water in contact with the atmosphere. Secondly, it dilutes the seawater at the surface, altering the chemical equilibrium within the oceanic carbon cycle and enabling seawater to absorb greater quantities of CO2. Finally, raindrops directly inject CO2 absorbed during their fall into the ocean through wet deposition.
Monrovia – On September 9, 2024, Monrovia will host a significant scientific gathering as the Government of Liberia, in partnership with the United Methodist University (UMU) and the Environmental Protection Agency (EPA) of Liberia, presents the Basic Ocean Acidification Training Course from September 9-13, 2024. This landmark event, the first of its kind in the region, aims to significantly enhance the scientific capabilities of West African nations in monitoring and addressing the impacts of ocean acidification.
The training course, organized by the Ocean Acidification International Coordination Centre (OA-ICC) of the International Atomic Energy Agency (IAEA), the Global Ocean Acidification Observing Network (GOA-ON), and the Ocean Acidification Africa (OA-Africa) Network with additional financial support from the International Alliance to Combat Ocean Acidification (OA Alliance), offers a unique and invaluable opportunity for 17 early-career scientists from West Africa. This is a chance for these scientists from Angola, Gambia, Ghana, Liberia, Nigeria, and Togo to be inspired, learn, and make a real difference in the fight against ocean acidification. Three IAEA experts will carry out the training.
Dr. Yar-Donlah Gonway Gono, President of the United Methodist University (UMU), highlighted the importance of the upcoming training: “This course represents a crucial step forward in building the scientific capacity needed to tackle one of the most pressing environmental challenges facing our region. The launch of the Gulf of Guinea Ocean Acidification Network during this event will further solidify our commitment to regional cooperation in protecting our marine resources for future generations.”
The course provides a blend of theoretical lectures, discussions, and workshops, strongly emphasizing Sustainable Development Goal 14.3.1 reporting. Participants will acquire the necessary tools for conducting ocean acidification research and monitoring in their respective countries and the practical skills to make a real difference in their communities and the wider region. This hands-on approach will empower them with the confidence and capability to act and contribute to the global effort to combat ocean acidification.
Dr. Emmanuel Yarkpawolo, Executive Director of the Environmental Protection Agency (EPA) of Liberia, emphasized the significance of the training: “This training will empower our scientists and communities with the knowledge and resources needed to protect our marine ecosystems and ensure the sustainability of our ocean resources.”
Hon. Karishma P.H. Pelham-Raad, The Assistant Minister for International Organizations-Ministry of Foreign Affairs (MOFA) of Liberia and National Liaison Officer (NLO) to the International Atomic Energy Agency (IAEA), emphasized the importance of the training for African Member states. This is crucial because Africa has extensive coastlines bordering the Atlantic and Indian Oceans, the Red Sea, and the Mediterranean Sea, which are vital for the continent’s US$300 Billion blue economy. Ocean acidification can harm coral health, fisheries, and the marine food chain, threatening food security and economic livelihoods.
Ms. Lina Hansson, from the IAEA Ocean Acidification International Coordination Centre and one of the lecturers, said that the training is an essential step towards supporting West African IAEA Member States to measure and act on ocean acidification.
During the training week, the OA-Africa Steering Committee will discuss the network’s future strategy and review ongoing regional initiatives. This meeting will provide a platform for experts to collaborate on solutions for the growing challenges of ocean acidification across Africa.
The training aims to raise awareness and promote international cooperation on research into ocean acidification.
Connecticut and Houstatonic river discharge and ratios of dissolved organic carbon to total alkalinity for the tributaries and west Long Island Sound across the study interval of 2020–2022. Credit: Frontiers in Marine Science (2024). DOI: 10.3389/fmars.2024.1398087
New York’s Long Island Sound (LIS) is an important inlet and estuary in the North Atlantic Ocean, which is highly urbanized due to its proximity to the city. This daily activity of passenger transport, fishing and cargo ships has had significant consequences on the marine landscape here, resulting in environmental degradation that impacts the flora and fauna that call LIS home.
Deep sea coral (NOAA file image). The zone where carbonate-containing life forms like these dissolve is set to expand by about 14 million square miles.
In the deepest parts of the ocean, below 4,000 meters, the combination of high pressure and low temperature creates conditions that dissolve calcium carbonate, the material marine animals use to make their shells.
This zone is known as the carbonate compensation depth – and it is expanding.
In the deepest parts of the ocean, below 4,000 metres, the combination of high pressure and low temperature creates conditions that dissolve calcium carbonate, the material marine animals use to make their shells.
This contrasts with the widely discussed ocean acidification of surface waters due to the ocean absorbing carbon dioxide from the burning of fossil fuels.
But the two are linked: because of rising concentrations of carbon dioxide in the ocean, its pH is decreasing (becoming more acidic), and the deep-sea area in which calcium carbonate dissolves is growing, from the seafloor up.
The transition zone within which calcium carbonate increasingly becomes chemically unstable and begins to dissolve is called the lysocline. Because the ocean seabed is relatively flat, even a rise of the lysocline by a few metres can rapidly lead to large under-saturated (acidic) areas.
Our research showed this zone has already risen by nearly 100 metres since pre-industrial times and will likely rise further by several hundreds of metres this century.
Millions of square kilometres of ocean floor will potentially undergo a rapid transition whereby calcareous sediment will become chemically unstable and dissolve.
Expanding boundaries
The upper limit of the lysocline transition zone is known as the calcite saturation depth, above which seabed sediments are rich in calcium carbonate and ocean water is supersaturated with it. The calcite compensation depth is its lower limit, below which seabed sediments contain little or no carbonate minerals.
The carbonate content of seafloor sediments decreases within the lysocline, reaching zero below the carbonate compensation depth (CCD). Above the lysocline is the calcite saturation depth (CSD), with seabed sediments rich in calcium carbonate. Author provided, CC BY-SA
The area below the calcite compensation depth varies greatly between different sectors of the oceans. It already occupies about 41% of the global ocean. Since the industrial revolution, this zone has risen for all parts of the ocean, varying from almost no rise in the western Indian Ocean to more than 300 metres in the northwest Atlantic.
If the calcite compensation depth rises by a further 300 metres, the area of seafloor below it will increase by 10% to occupy 51% of the global ocean.
These maps show the changes in area of ocean exposed to corrosive bottom waters in 17 different regions. The pre-industrial CCD is dark blue and areas above the lysocline are light blue. Map A shows the present day and map B shows a lysocline rise of 300 metres. Author provided, CC BY-SA
Distinct habitats
For the first time, a recent study showed the calcite compensation depth is a biological boundary with distinct habitats above and below it. In the northeast Pacific, the most abundant seabed organisms above the calcite compensation depth are soft corals, brittle stars, mussels, sea snails, chitons and bryozoans, all of which have calcified shells or skeletons.
However, below the calcite compensation depth, sea anemones, sea cucumbers and octopus are more abundant. This under-saturated (more acidic) habitat already limits life in 141 million square kilometres of the ocean and could expand by another 35 million square kilometres if the calcite compensation depth were to rise by 300 metres.
Thus, the most liveable habitat space for marine species is shrinking from the bottom (rising calcite compensation depth) and the top (warming).
Island nations most affected
The exclusive economic zones of some countries will be more affected than others. Generally, oceanic and island nations lose more, while countries with large continental shelves lose proportionately less.
Bermuda’s EEZ is predicted to be the most affected by a 300-metre rise of the calcite compensation depth above the present level, with 68% of that country’s seabed becoming submerged below the lysocline. In contrast, only 6% of the US EEZ and 0.39% of the Russian EEZ are predicted to be impacted.
From a global perspective, it is remarkable that already 41% of the deep sea is effectively acidic, that half may be by the end of the century, and that the first study showing its effects of marine life was only published in the past year.
“Oceans aren’t just a nice backdrop for your selfies in summer…”
The world’s oceans are in hot water, and it’s not just because of Earth’s overheating.
What’s happening?
The world’s oceans are confronting a “triple threat” of extreme heating, oxygen loss, and acidification. As reported by the Guardian, this alarming trend, driven by human activities such as pollution and deforestation, has escalated dramatically in recent decades.
Research published in AGU Advances reveals that about a fifth of the world’s ocean surface is particularly vulnerable to these compound threats. In the top 300 meters of the ocean, these extreme conditions now last three times longer and are six times more intense than in the 1960s.
Joel Wong, lead author of the study and researcher at ETH Zurich, emphasized that the climate crisis is pushing our oceans into a dangerous new state.
The impacts of this have already been seen and felt. Intense extreme events like these are likely to happen again in the future and will disrupt marine ecosystems and fisheries around the world,” Wong said, via the Guardian.
