Ocean Acidification Impacts on Marine Life

Shell-Builders at Risk
Ocean acidification is causing seawater pH to drop as it absorbs increasing amounts of carbon dioxide.

One of the clearest impacts is on marine organisms that use calcium carbonate to build shells and skeletons.

Mollusks such as clams, oysters, and mussels experience thinner, less viable shells, and reduced growth rates.

For example, in the Sunderbans estuary, declines in pH have been directly linked to a 35–40% reduction in shelled organism populations, with the edible oyster Saccostrea cucullata now averaging shells over 40% smaller than historical norms.

Larval stages are especially vulnerable—exposing shrimp larvae in the Arabian Gulf to low pH and high temperatures leads to very high mortality; surviving juveniles are smaller and weaker, threatening local fisheries and commercial harvests .

Some practical responses include adding crushed shells to buffer the local water or farming kelp nearby to absorb CO2; these interventions have helped maintain growth and viability in young shellfish under acidified conditions .

Cephalopods and Acidification
Though cephalopods like cuttlefish and octopuses do not have large external shells, recent laboratory studies show that ocean acidification can nonetheless affect their early development and behavior.

For instance, cephalopod embryos and hatchlings exposed to low pH conditions may experience altered rates of calcium uptake, changes in metabolic rates, and shifts in hunting efficiency or prey detection.

While some species show resilience, others demonstrate disrupted development or behavior patterns under acidified conditions.

These changes could influence survival, growth, and ecological roles—potentially reducing their populations or altering food web dynamics if their natural prey is also affected by acidification and warming .

Marine Mammals and Food Webs

The primary effect of ocean acidification on marine mammals—such as whales, seals, and dolphins—is through disruption of the food web.

For example, annual NOAA and IPCC reports document how reductions in Arctic sea ice and shifting plankton and fish populations, linked to acidification, have caused the timing and location of major prey blooms to change.

Such changes challenge marine mammal reproductive success: gray seals, for instance, may find their preferred prey less frequently during nursing and breeding periods, threatening pup survival.

Similarly, whales migrating long distances may encounter fewer or less nutritious prey, observed through long-term research on feeding trends and calf survival rates in Arctic and subarctic waters .

Plankton Communities and Fisheries
Plankton, the base of marine food webs, are particularly sensitive to acidification.

Many important species, such as copepods and pteropods (“sea butterflies”), make shells of forms of calcium carbonate that dissolve more readily in acidic conditions.

Experimental work on Arctic copepods shows that acidification and warming together increase larval respiration and stress, making early life stages a “bottleneck” for population growth.

These plankton declines have cascading consequences: as their populations drop, food for fish, whales, and seabirds becomes less reliable, threatening the productivity of entire fisheries .

Ecosystem Changes and Compounding Stressors

The effects of ocean acidification rarely occur in isolation—they frequently amplify the impacts of other environmental threats such as warming, loss of oxygen (deoxygenation), and occasional harmful algal blooms.

For instance, research on commercial shrimp species in Kuwait demonstrated that while acidification and warming each independently reduce larval survival and growth, together they have even stronger negative effects .

Dead zones and sea level rise, combined with acidification, are projected to cause the loss of fisheries and coastal habitats relied on by over 40% of the world’s population by mid-century .

Fisheries and Economic Impacts
Declining populations of shelled organisms, reduced fish survival, and shrinking plankton base directly threaten wild harvests and aquaculture.

Quantitative models indicate that by 2100, the commercial Dungeness crab fishery in the Pacific Northwest may see sharp declines linked to acidification—a vital resource for regional Indigenous and commercial communities .

More broadly, without intervention, major oyster and mussel fisheries could collapse as acidification progresses; this would endanger food security for over half a billion people globally .

Projected Future Changes
By the end of the century, projections show surface pH in the Indian Ocean and many other regions could fall below 7.7 (down from 8.1), equating to a dramatic increase in acidity.

Primary productivity and chlorophyll—a measure of ocean life—could drop by 8–10% in some areas, leading to further declines across marine food webs .

Key Takeaways for Posters & Pamphlets
- Many mollusks and shellfish now have shells up to 40% thinner/smaller, with 35–40% population declines in some estuaries, threatening local fisheries .
- Cephalopods, including cuttlefish, may experience altered development and predator behaviors under acidification, especially as their prey and local ecosystems shift .
- Marine mammals such as seals and whales are impacted by prey shortages as acidification disrupts plankton and fish populations—notably in the Arctic .
- Plankton community stress lowers the base of ocean food webs, risking fisheries collapse and threatening global food supply .
-

By 2100, some ocean regions may see pH drop below 7.7, with 8–10% primary productivity loss—a threat to ocean biodiversity and fisheries .

- Ecosystem stress is intensified when acidification is combined with warming, oxygen loss, and pollution, accelerating losses of species and habitats .

Summary
Ocean acidification is a major and growing threat to marine species and entire ecosystems.

While corals are often cited as the most visible victims, many less familiar but vital organisms—from tiny plankton and shellfish to iconic cephalopods and marine mammals—are also at risk.

These changes not only reduce biodiversity but also jeopardize fisheries, coastal livelihoods, and food security for millions worldwide.

Scientific models, field cases, and experimental studies all point to the urgent need for action to limit and adapt to ocean acidification’s impacts.

Ocean Acidification Impacts on Marine Life

Shell-Builders at Risk
Ocean acidification is causing seawater pH to drop as it absorbs increasing amounts of carbon dioxide.

Title:

Content: Rapid warming of Indian ocean could lead to catastrophic outcomes: Study

The heat content of the Indian Ocean, from the surface to a depth of 2,000 meters, is currently increasing at the rate of 4.5 zetta-joules per decade.

Press Trust of India New Delhi
4 min read Last Updated : Apr 28 2024 | 1:54 PM IST

The Indian Ocean is expected to experience surface warming of 1.4 degrees Celsius to 3 degrees Celsius between 2020 and 2100, which will push it into a near-permanent heatwave state, intensify cyclones, affect the monsoon, and lead to a rise in sea levels, according to a new study.

The study, led by Roxy Mathew Koll, a climate scientist at the Pune-based Indian Institute of Tropical Meteorology (IITM), showed that marine heatwaves (periods of abnormally high ocean temperatures) are projected to increase from 20 days per year (during 1970-2000) to 220-250 days per year, pushing the tropical Indian Ocean into a basin-wide near-permanent heatwave state by the end of the 21st century.

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Marine heatwaves cause habitat destruction due to coral bleaching, seagrass destruction, and loss of kelp forests, affecting the fisheries sector adversely. They also lead to the rapid intensification of cyclones.

The rapid warming in the Indian Ocean is not limited to the surface. The heat content of the Indian Ocean, from the surface to a depth of 2,000 meters, is currently increasing at the rate of 4.5 zetta-joules per decade and is predicted to increase at a rate of 16-22 zetta-joules per decade in the future, the study titled "Future projection for the tropical Indian Ocean" said.

"The future increase in heat content is comparable to adding the energy equivalent of one Hiroshima atomic bomb detonation every second, all day, every day, for a decade," Koll said.

The maximum warming will occur in the northwestern Indian Ocean, including the Arabian Sea, while there will be reduced warming off the Sumatra and Java coasts.

Amid the accelerated ocean warming, the seasonal cycle of surface temperatures is projected to shift, which could increase extreme weather events over the Indo-Pacific region.

While the maximum basin-average temperatures in the Indian Ocean ranged from 26 degrees Celsius to 28 degrees Celsius throughout the year during 1980-?2020, the minimum temperatures by the end of the 21st century will be between 28.5 degrees Celsius and 30.7 degrees Celsius year-round, under a high emission scenario.

Sea surface temperatures above 28 degrees Celsius are generally conducive to deep convection and cyclogenesis. Heavy rainfall events and extremely severe cyclones have already increased since the 1950s and are projected to increase further with increasing ocean temperatures, the authors said.

The increased ocean heat could also lead to a rise in sea level. Thermal expansion of water contributes to more than half of the sea level rise in the Indian Ocean, which is larger than the contribution from glacier and sea-ice melting.

The Indian Ocean Dipole, a phenomenon that affects the monsoon and cyclone formation, is also predicted to change. The frequency of extreme dipole events is predicted to increase by 66 per cent whereas the frequency of moderate events is to decrease by 52 per cent by the end of the 21st century.

The authors of the study predicted that ocean acidification will intensify, with surface pH decreasing from a pH above 8.1 to below 7.7 by the end of the century. Surface chlorophyll and net primary productivity are also predicted to decline, with the strongest decrease of about 8-10 per cent in the western Arabian Sea.

"The projected changes in pH may be detrimental to the marine ecosystem since many marine organisms, ?particularly corals and organisms that depend on calcification to build and maintain their shells, ?are sensitive to the change in ocean acidity. The change may be easier to fathom when we realise that a 0.1 fall in human blood pH can result in rather profound health consequences and multiple-organ failure," Koll said.

Bordered by 40 countries, and home to a third of the global population, changes to climate in the Indian Ocean region have major societal and economic impacts.

Currently, the Indian Ocean and its surrounding countries stand out globally as the region with the highest risk of natural hazards, with coastal communities vulnerable to weather and climate extremes.

Topics :Global WarmingIndian Oceanweatherheat

First Published: Apr 28 2024 | 1:54 PM IST

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What factors lead to damage of coral reefs?

What is the main cause of ocean acidification?

water absorbs carbon dioxide from the atmosphere

One of the clearest impacts is on marine organisms that use calcium carbonate to build shells and skeletons.

Title:

Content: How climate change and warming waters are affecting the health of the oceans

(NEW YORK) — Oceans do so much to sustain life on Earth, including bearing the brunt of global temperatures that have been steadily warming for decades.

An IPCC special report published in 2019 found that oceans — which make up more than 70% of the world’s surface — have absorbed between 20% and 30% of human-made carbon dioxide emissions since the 1980s. They’re also responsible for absorbing more than 93% of the “combined heat stored by warmed air, sea, and land, and melted ice” since the 1970s, according to the Fifth Assessment report published in 2013 by the United Nations Intergovernmental Panel on Climate Change.

The tipping point is near, experts told ABC News. But there are collective actions to take that could revitalize oceans to a healthier state — the theme of the United Nations World Oceans Day 2022.

“We really see oceans as the biggest ally in the climate change crisis,” Lea d’Auriol, founder of nonprofit Oceanic Global, told ABC News.

This is how climate change is affecting the health of the world’s oceans:

Species are faced with adapting or becoming extinct

Currently, the oceans “are in a state of complete imbalance” that has nearly doubled since the 1990s, d’Auriol said. Look no further than the fishermen, who supply sustenance to more than three billion people who rely on seafood as their main source of protein, as witnesses that climate change is already here, d’Auriol, said.

“If you wanted to ask someone if climate change is really happening, probably the most surest answer you’d get from anyone aside from a scientist is a fisherman,” Arlo Hemphill, senior oceans campaigner for Greenpeace USA, told ABC News. “Because fishermen are seeing these things happen in real time.”

One of the changes long-time fisherman are witnessing is the presence of new species venturing north as the area with their preferred water temperature expands.

Marine organisms maintain the same temperature as the surrounding water, so that when temperature increases, so does the temperature of the organism, Martin Grosell, professor of ichthyology and chair of the University of Miami’s Department of Marine Biology and Ecology, told ABC News. As the temperature rises, the organisms require more energy to move and survive. But, conversely, the levels of oxygen in the water decrease as the temperature warms, forcing the species to move, Grosell said.

The migrations may seem innocuous, but they are disrupting ecosystems all over the world, such as the phenology, or timing, of when grey seals give birth, Hemphill said.

Conversely, species are continuing to die off due to repeated events of marine heatwaves, Anne Christianson, director of international climate policy for the Center for American Progress, a public policy research organization, told ABC News.

Coral reefs are among the most threatened marine ecosystems in the world, scientists say. Coral bleaching, a process that occurs when water is too warm and the corals expel algae from their tissues, causing them to turn completely white, is happening at “alarming” rates — increasing by a rate of 4% per year — along with an uptick in mortality events along entire regions, d’Auriol said.

A study published in the National Academy of Sciences found that coral reefs could stop growing in 10 years unless greenhouse gases are significantly reduced and that, under a worst-case scenario, 94% of all reefs could erode by 2050.

Reefs are often the indicator of the health of an ecosystem, Brenda Ekwurzel, director of climate science for the Union of Concerned Scientists, told ABC News.

Mammals that rely on Arctic ice, such as polar bears and ringed seals, one of the polar bears’ main food sources that live their lives almost entirely on the ice, are also at risk, Ekwurzel said.

Vegetation such as mangroves, seagrass plants and marshes, some of the largest carbon sinks on the planet, which absorb and store carbon dioxide from the atmosphere, are also at risk of extinction, d’Auriol said.

The number of dead zones are increasing

A dead zone, or the process of hypoxia, occurs when an algal bloom sucks up all the oxygen in an area, making it impossible for marine life to survive — essentially a biological desert, according to the National Oceanic and Atmospheric Administration.

A study published in 2008 in Science found that there were 400 dead zones around the world. By 2019, the number of dead zones had increased to about 900, d’Auriol said.

The dead zones often occur in regions with rampant nutrient runoff, such as at the base of the Mississippi River, where it empties into the Gulf of Mexico, Hemphill said.

Sea level rise will change coastal communities

The biggest contributor to sea level rise is the melting ice in the Arctic, which is heating up twice as fast as the rest of the world, according to the 2021 Arctic Report Card by NOAA. Increases in sea level rise of 6 inches to a foot since the Industrial Revolution may seem like small increments, but crucial infrastructure near oceans was not built to withstand the added inches of water, experts say.

Millions of people living in coastlines around the world, including those in mega cities such as New York, Los Angeles and San Francisco, will be displaced by the rise in sea levels, d’Auriol said.

Carbon dioxide emissions sparks ocean acidification

Ocean acidification, which occurs when water’s pH levels are lowered as a result of carbon dioxide in the atmosphere, is not directly caused by warming temperatures but rather by excess carbon dioxide emissions, Hemphill said.

“The alarming thing about it is that shellfish everything from from microscopic plankton, to clams and crabs and coral reefs themselves use calcium carbonate to build their shells,” he said. “And as the ocean acidifies, it becomes more difficult to create the shells.”

Ocean acidification, rather than coral bleaching, will likely be the culprit behind the demise of coral reefs, Ekwurzel said.

Collective actions are necessary to protect the oceans

In line with the 2022 theme for World Oceans Day, “Revitalization: Collective Action for the Ocean,” scientists and conservationists are highlighting the need for individuals, communities, nonprofits, the private sector and governments to come together to create solutions, d’Auriol said.

This includes ensuring the health of marine protected areas by eliminating housing, fishing zones and shipping traffic in the vicinity, d’Auriol said.

Governments will need to create policies to protect both human life and the health of the ocean, Christianson said.

“There isn’t one silver bullet for solving this crisis in the ocean and on land,” Christianson said.

However, the ticking time bomb is the race to drastically reduce global greenhouse gas emissions within the next decade, the experts said.

“We can’t afford to delay those solutions any longer,” Ekwurzel said.

Along the path to properly protecting and preserving oceans is ridding the narrative that oceans are a separate environmental issue from climate change and the conservation of biodiversity, d’Auriol said.

“Because we do live on a water planet, and it’s responsible for sustaining all life on Earth,” she said.

Copyright (C) 2022, ABC Audio. All rights reserved.

What do shellfish use to build their shells?

What factors lead to damage of coral reefs?

Mollusks such as clams, oysters, and mussels experience thinner, less viable shells, and reduced growth rates.

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Content: Credits: Maxpixel

The Logical Indian Crew

Rise In CO2 Levels In Air Is Wounding Sundarbans' Marine Life: Scientists

This has been analysed by a team of marine scientists working in the Sunderbans, who said ocean acidification is a part of global warming and climate change. The experts found the pH level of water dropping from around 8.3 in the early 1980s to approximately 7.9 in 2019.

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A continuous increase in the carbon dioxide (CO2) levels in the air is harming the marine life of the Sunderbans estuary in West Bengal by turning it acidic. Animals, especially with shells such as oysters, clams, crabs, and lobsters, are prone to danger.

This has been analysed by a team of marine scientists working in the Sunderbans, who said ocean acidification is a part of global warming and climate change, Hindustan Times reported. The experts found the pH level of water dropping from around 8.3 in the early 1980s to approximately 7.9 in 2019.

Speaking to the media, Abhijit Mitra, former head of the marine science department (Calcutta University), informed that the western part of Sunderban, close to the urban area, had observed a massive drop in its pH level, while the central part is declining slowly.

Mitra said the decline affects the population of shelled organisms and their shell size as well, which has become thinner and smaller. Fishermen said that several fish and other animals have gotten smaller, and they hardly get big ones.

Their population has also fallen by 35-40 per cent in the western area.

"The size of Saccostrea cucullata, a species of edible oyster around Kakdwip and Namkhana fishing harbour, has dropped by over 40 per cent. In the central Sunderbans, the size of the species has dropped by around 20 percent," the media quoted him as saying.

Asst. Professor of Indian Institute of Science Education and Research, Punyasloke Bhadury, explained that water contains calcium and carbonate ions, which the shelled animals need to develop and corals to build the reef. But the acidity reduces these components in the water, affecting the shell size and slowing down the growth of reefs.

Experts said the decline in the pH level is alarming. Just as the slightest drop in the pH level of a human body (pH 7.35 to 7.45) can make them sick, the same takes a heavy toll on marine animals.

The scientists said the decline is not just in Sunderbans but other estuaries as well.

Also Read: Rajasthan Bride Asks Father To Build Girls Hostel With Money Set Aside For Marriage

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How does coastal ocean acidification affect shellfish?

For example, in the Sunderbans estuary, declines in pH have been directly linked to a 35–40% reduction in shelled organism populations, with the edible oyster Saccostrea cucullata now averaging shells over 40% smaller than historical norms.

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

Larval stages are especially vulnerable—exposing shrimp larvae in the Arabian Gulf to low pH and high temperatures leads to very high mortality; surviving juveniles are smaller and weaker, threatening local fisheries and commercial harvests .

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In cooperation with the Foundation for the Advancement of Science and the Atomic Energy Agency
« Research » conducted a study on the impact of « acidification » on shrimp
The Kuwait Institute for Scientific Research (KISR), in cooperation with the Kuwait Foundation for the Advancement of Sciences (KFAS) and the International Atomic Energy Agency (IAEA), completed a study project to investigate the impact of ocean acidification and ocean surface warming on the growth and abundance of local shrimp.
In turn, the head of the project, researcher Lamia Muslim at the Center for Environmental and Life Sciences Research at the Institute, said that there are many animals that contain in their skeleton or shell calcium carbonate, and changes in the pH of water can negatively affect these organisms, especially in the early stages of their life. The sea and some phytoplankton species, but that does not mean that this is a positive thing because the increased growth of these organisms can disrupt the food chain, biodiversity and ecosystem mechanisms and construction.
She added that the presence of large amounts of carbon dioxide in the atmosphere leads to the occurrence of global warming and the rise of the surface of the oceans by between one and three degrees Celsius, and the rise of the water level to an amount ranging from 0.18 to 0.79 meters, which in turn leads to acidification and warming of the surface of the oceans, and therefore to change the chemistry of the ocean and threaten marine ecosystems.
She pointed out that the shrimp mothers were collected from Kuwaiti territorial waters during the breeding season to obtain eggs and shrimp larvae in sufficient numbers to conduct experiments on all stages of shrimp age, as the study experiments were conducted in the laboratories of the Institute in a controlled system simulating the expected climate changes in the future.
The results of the study confirmed that the warming of the surface of the oceans could have a greater impact than ocean acidification on the early life stages of shrimp larvae, as shrimp larvae exposed to high temperatures showed accelerated growth rates to reach the sizes of older shrimp, but with lower survival rates, it is very likely that lower survival and growth rates under future climate scenarios may lead to the emergence of smaller shrimp larvae. These larvae will undergo multiple molting processes over their life cycle making them vulnerable; furthermore, the study results suggest additional effects of combined exposure to ocean surface warming and acidification on egg-hatching success, survival, and shrimp larval development.
Al-Musallam said: “The study is fully consistent across the entire life cycle of the M Nair shrimp, where high mortality of larvae at low pH and high water temperature indicates a possible collapse of this species of crustacean under conditions of increased ocean acidification and future warming of the ocean surface, which also leads to a significant reduction in shrimp stocks in the Arabian Gulf due to overfishing or reduced larval growth due to climate change. ”
For his part, dr.
Dr. Saifuddin Iqbaluddin, from the Center for Environmental and Life Sciences Research, said experts regularly measure water temperature and pH levels and look at how marine life might respond to these changes in the coming decades.
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At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

How does coastal ocean acidification affect shellfish?

Some practical responses include adding crushed shells to buffer the local water or farming kelp nearby to absorb CO2; these interventions have helped maintain growth and viability in young shellfish under acidified conditions .

Title:

Content: There were 1,862 press releases posted in the last 24 hours and 393,697 in the last 365 days.

Utilizing biogeochemical and genetic tools to understand and support clam populations in a changing ocean

Marine bivalves are at risk due to anthropogenic climate change. This poses a threat to commercial aquaculture, and the communities that depend on bivalves for food security. Ocean acidification, the lowering of seawater pH, is of particular concern for marine calcifiers, including bivalves. Ocean acidification occurs as carbon dioxide enters the atmosphere at a rate faster than natural geologic processes can buffer. It is energetically costly for marine calcifiers like clams, mussels, and oysters, to mineralize under acidic conditions, and low pH leads to the dissolution of calcium carbonate shells and skeletons. This problem warrants research on acidification adaptation strategies that will keep coastal populations healthy. Adding calcium carbonate shell hash to coastal sediments may mitigate negative effects of acidification on infaunal shellfish by altering the chemistry of pore fluids, thus providing a potential mitigation strategy for local populations, including species like the Pacific littleneck clam (Leukoma staminea).

Here, I present the first in-depth description of the shell mineralogy, microstructure, body size variability, and geochemical properties of modern L. staminea, a common eastern Pacific, shallow, infaunal bivalve. Additionally, I document the impact of ocean acidification on the shell growth and gene expression of L. staminea, and test whether adding shell hash to its infaunal environement can promote growth under acidified conditions. Juvenile clams were raised in four experimental conditions for 90 days: control seawater, acidified seawater, control seawater with shell hash, and acidified seawater with shell hash. Clam shell weight, soft tissue weight, and new shell growth were measured. The presence of shell hash increased the pH, alkalinity and aragonite saturation state of pore fluids across all treatments, and increased shell growth on average, although growth metrics were variable across and within treatments. Lastly, RNA-sequencing revealed the impacts of experimental acidification on juvenile clam gene expression. Clams grown in the presence of shell hash had gene expression profiles more similar to those grown in control (non-acidified) conditions. In all, this research suggests that adding shell hash to coastal sediments alters the chemistry of pore fluids and buffers against acidic conditions that deleteriously affects clam mineralization.

Kempf H., 2024. Utilizing biogeochemical and genetic tools to understand and support clam populations in a changing ocean. PhD Thesis, University of California, Davis. 33 p. Thesis (restricted access).

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At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How does coastal ocean acidification affect shellfish?

Cephalopods and Acidification
Though cephalopods like cuttlefish and octopuses do not have large external shells, recent laboratory studies show that ocean acidification can nonetheless affect their early development and behavior.

Title:

Content: Newswise — STONY BROOK, NY, May 25, 2022 – While kelp is known as a nutritious food item for sea creatures and humans alike, harvesting kelp may be a new way to help keep bivalves such as clams and oysters – a more common food source and marine industry staple – healthy and more abundant. A new study led by Christopher Gobler, PhD, and a team of scientists at the Stony Brook University School of Marine and Atmospheric Sciences (SoMAS) shows that the presence of kelp significantly reduces ocean acidification, a result of climate change.

Published in Frontiers in Marine Science, the study also demonstrated that the deployment of kelp on an oyster farm nullifies ocean acidification and therefore protects bivalves against acidification. The process may also have additional ecosystem and aquaculture benefits, including the sequestration and extraction of carbon and nitrogen, and protection against harmful algae blooms.

For shellfish, one of the most serious climate change-related threats is ocean acidification. Carbon dioxide or CO2 levels in Earth’s atmosphere continue to rise, infiltrating oceans where it causes chemical reactions that lower pH and cause ocean acidification. For the past two decades, one of the most robust conclusions of ocean climate change research has been that increasing levels of CO2 in surface waters threaten shellfish that rely on higher pH waters to grow and survive. This threat is particularly acute in coastal zones where additional sources of acidity can further reduce pH and slow shell formation in shellfish, especially bivalves. And while many wild populations of bivalves have collapsed, a burgeoning wave of aquaculture in the U.S. and around the World has caused the global production of seafood via aquaculture to grow and now exceed wild capture.

“Despite this wave of aquaculture, the intensification of ocean acidification now threatens bivalve aquaculture and has necessitated a solution,” explains Professor Gobler, the Endowed Chair of Coastal Ecology and Conservation at SoMAS.  “We believe our work is foundational to a solution.”

In the study, titled “Kelp (Saccharina latissima) Mitigates Coastal Ocean Acidification and Increases the Growth of North Atlantic Bivalves in Lab Experiments and on an Oyster Farm,” Professor Gobler and colleagues conducted six experiments to assess the effects of elevated CO2 and presence of kelp (S. latissima) on the growth rates of three different species of bivalves: (Eastern oysters (Crassostrea virginica), blue mussels (Mytilus edulis), and hard clams / Northern quahogs (Mercenaria mercenaria).

In each of the experiments, acidification was significantly reduced with the cultivation of kelp. They furthered the research with the ultimate test – a field experiment at the Great Gun oyster farm in Moriches Bay, New York.

They found that during a one-month deployment, oysters that were surrounded by kelp enjoyed higher pH water and grew significantly faster than individual shellfish located further away where the pH of the water was significantly lower.

Professor Gobler and colleagues emphasize that these findings have powerful implications for oyster farming in coastal zones.

“We have been witnessing coastal ocean acidification for years and have documented its ability to slow the growth, and even kill off, shellfish. We began growing kelp on oyster farms to simply expand aquaculture, regionally. After seeing its ability to rapidly take up CO2 and improve low pH conditions, we knew it had the potential to benefit shellfish experiencing acidification. And while showing that in the lab was exciting, being able to improve the growth of oysters on an oyster farm experiencing coastal acidification proves this approach can have very broad applications,” explains Professor Gobler.

Overall, the research clearly shows, according to the authors, that “the cultivation of kelp constitutes an environmentally friendly means of protecting shellfisheries against present and future ocean acidification and other coastal stressors.”

Building on the work, helping the oyster farms

“We’ve helped grow kelp on 10 oyster farms across New York since 2018 and more and more aquaculturists have been hoping to incorporate kelp into their farms,” says Mike Doall, Associate Director of Shellfish Restoration and Aquaculture at Stony Brook University. “In addition to providing crop diversification and additive revenue streams, the ability of kelp to fight ocean acidification gives these oyster farmers one more reason to add kelp as a second crop.”

The recent study builds on other research by the same SoMAS group, which published a study in Harmful Algae in 2021. That study demonstrated that kelp has the ability to deter the intensity of harmful algal blooms, another environmental threat to shellfish aquaculture.

Such scenarios with kelp appear to create a win-win scenario for oyster farmers like Paul McCormick, owner of the Great Gun oyster farm where the current study was performed.

“Kelp looks to be the perfect complement to oysters on my farm,” says McCormick. “It grows during winter and spring, when the oysters need less attention, and there is lots of interest in kelp from restaurants. If it is offering protection to my oysters against poor water quality, well that’s another good reason to add it to my farm.”

Citations:

Young, C. S., Sylvers, L. H., Tomasetti, S. J., Lundstrom, A., Schenone, C., Doall, M. H., & Gobler, C. J. (2022) Kelp (Saccharina latissima) mitigates ocean acidification and increases the growth of North Atlantic bivalves in lab experiments and on an oyster farm. Frontiers in Marine Science, Volume 9 | Article 881254

Sylvers, P. H., & Gobler, C. J. (2021). Mitigation of harmful algal blooms caused by Alexandrium catenella and reduction in saxitoxin accumulation in bivalves using cultivable seaweeds. Harmful Algae, 105, 102056.

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At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

Which marine organism is vulnerable to increased levels of ocean acidification?

For instance, cephalopod embryos and hatchlings exposed to low pH conditions may experience altered rates of calcium uptake, changes in metabolic rates, and shifts in hunting efficiency or prey detection.

At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

Which marine organism is vulnerable to increased levels of ocean acidification?

While some species show resilience, others demonstrate disrupted development or behavior patterns under acidified conditions.

Title:

Content: Carbon Dioxide Makes Ocean Acidification Study Suggests Rapid Evolution Could Make Fish Easier to Deal With
March 03, 2022 17: 00
Eastern Network Television
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Some fish can evolve rapidly to cope with ocean acidification.
(courtesy of Shutterstock)
In addition to causing climate warming, global emissions of large amounts of carbon dioxide will also cause sea water to become acidic, and marine life may be affected.
The study found that volcanic infiltration of high CO2 partial pressure, that is, high concentrations of CO2 dissolved in water, changes in the genetic transcription of fish, predict the response of wild fish to the continuous acidification of the marine environment.
The results show that some fish with faster rates of evolution may be more flexible in coping with ocean acidification, maintaining population size and diversity. One species of fish may be able to acidify the marine environment with its rapid evolution of gene molecular transcription regulation, but the population size and diversity of fish with slower rates of evolution are difficult to maintain in acidified environments.
As carbon dioxide emissions from human activities increase year by year, and the CO2 absorbed by the ocean continues to rise, causing the pH of seawater to decline and become acidic, scientists expect “ocean acidification ” on the surface of the world ’ s oceans, which may affect the physiology, growth and survival of some fish, and change some key behaviors that affect survival chances.
A team led by Celia SCHUNTER from the Faculty of Biosciences of the University of Hong Kong and the Swire Institute of Marine Science, along with foreign researchers, travelled to Papua New Guinea, the Pacific island nation, to extract the brains of six species of coral fish, including five species of finch and one species of celestial bream, from a carbon dioxide spill at the bottom of a volcano and about 500 m nearby coral reef. The organization conducts gene transcription group sequencing to understand the changes in fish gene transcription in the ocean acidification environment.
The results show that high CO2 partial pressure can cause transcription changes in genes related to circadian clock and immune function in several species, demonstrating that fish function is important in coping with acidifying environments, and that the core genes of circadian rhythms determine the 24-hour cycle of most species.
Immune-related regulation has been found in many species of fish in acidified environments, so regulation of the immune response may also be an important response to acidification, especially in nocturnal fish, which exhibit a greater proportion of immune regulation and are modulated in the opposite direction to diurnal fish.
In contrast to the fish body ’ s ability to regulate the pH value of the cells, the researchers found that the brain of the spinosus is used to maintain a large number of changes in potassium, sodium, chlorine and calcium ions that transmit signals in the carbon dioxide ooze. Corresponding changes are needed to cope with the acidification environment, but differences in the expression of related genes disappear when stress is reduced, and genes return to normal levels of expression.
Further research by the team found that this finch has evolved significantly faster than other fish over the past 15 million years, potentially giving it greater potential to adapt to environmental changes.
It is speculated that this species may have evolved molecular mechanisms to cope with future ocean acidification.

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

These changes could influence survival, growth, and ecological roles—potentially reducing their populations or altering food web dynamics if their natural prey is also affected by acidification and warming .

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Content: The Arctic region is currently undergoing rapid and significant changes, with acidification and warming occurring at alarming rates.
These shifts raise concerns about the resilience of marine communities in the face of such environmental shifts.
Marine zooplankton, especially copepods, play a crucial role in the Arctic food web.
However, differences in environmental conditions can disrupt zooplankton populations, leading to adverse consequences for the entire ecosystem.
Recent research has focused on understanding the extent to which copepods in early life are exposed to environmental stressors, as they represent a critical bottleneck in the copepods life cycle.
A study by Espinel Velasco et al.
(2023) Explore the responses of 4-day-old Kalanos Hyperborius Lenobli to acidification (pH 7.5 and 8.1) and warming (0 and 3 ° C), both individually and collectively.
The study revealed that the larvae 'breathing rates increased significantly when exposed to a combination of acidification and warming.
Surprisingly, exposure to these stressors individually did not produce the same effect.
Surprisingly, the researchers did not find any noticeable differences in fat content and fatty acid composition in the larvae across various experimental treatments.
Wax esters, which make up about 75% of the fat reserve, and high amounts of long-chain fatty acids 20: 1 and 22: 1, necessary for copepods to reproduce, have been detected in all treatments.
By highlighting the sensitivity of larvae to the combined effects of acidification and warming, this study aligns with a growing body of evidence from relevant research.
It highlights the potential impacts of global change on Arctic copepod populations and stresses the importance of understanding early life stage responses to environmental stressors.
Questions and Answers:
Q: What are zooplankton?
A: Zooplankton refers to small, often microscopic, organisms that drift into the ocean or other bodies of water and serve as one of the main sources of food for many marine species.
Q: What is the role of copepods in the Arctic food web?
A: Copepods, especially calanotic copepods such as Calanus Hyperboreus, are a critical component of the Arctic food web.
They serve as a vital link between primary producers (such as phytoplankton) and higher trophic levels, serving as a food source for various marine species.
Q: What is acidification?
A: Acidification refers to the process of increasing acidity (lowering pH) in seawater due to the absorption of carbon dioxide from the atmosphere.
This occurs as a result of human activities, such as the burning of fossil fuels.
Q: How does global warming affect marine ecosystems?
A: Ocean warming can have various impacts on marine ecosystems, including changes in species distribution, changing reproductive cycles, and potential disruptions to the delicate balance of food webs.
Source: Frontiers in Marine Science, DOI: 10.3389 / fmars.2023.1240673

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

How does elevated water acidity affect fish ability to survive?

Marine Mammals and Food Webs

The primary effect of ocean acidification on marine mammals—such as whales, seals, and dolphins—is through disruption of the food web.

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Content: If we continue to live the way we are, I am worried for the people who will see the next 90 years.
The latest scientific explanation suggests that the biological world is on the verge of destruction.
The collapse has indeed begun, and it is bound to accelerate, leading to an increase in the scale of the collapse and its impact.
Everything that we depend on for our survival — what our environment has always given us — may begin to falter or disappear altogether.
The predicted disaster will be more devastating than Chernobyl or any event to date, not only causing floods, powerful hurricanes and summer wildfires, but also reducing the quality of life for each victim and their descendants, with irreparable consequences.
When the global ecological collapse is finally resolved and a balance is reached, humanity will live forever on a barren planet if it still exists on Earth.
2030s
Decades of large-scale deforestation and illegal burning in the Amazon basin by people who want to develop more land for agricultural purposes will reduce the area of the Amazon rainforest to 75% of the original forest by the 2030s.
Although still massive, this could be a tipping point in the Amazon rainforest, triggering a phenomenon known as forest dieback.
Forests suddenly become unable to generate enough water from the shrinking canopy to nourish rain clouds, and the most vulnerable areas of the Amazon rainforest degenerate first into seasonal drylands and later into savannahs.
The phenomenon of this decline is self-propelled — the more cases of blight occur, the more trees will die; as a result, drought will quickly sweep across the Amazon basin, causing severe damage.
The loss of biodiversity is devastating, with one in 10 known species in the world inhabiting the Amazon basin, representing innumerable local extinctions that create a domino effect across the ecosystem.
All wild populations will be severely damaged, and it will become increasingly difficult for each individual to feed and find a mate.
Perhaps some of the species used in medicine, new food, and industry disappeared before we even knew it existed, and the human cost was even more profound and heavy.
As the forests wither, the Amazon basin floods frequently, flushing the soil from tree roots into rivers; 30 million people may have to leave the watershed, including nearly 3 million native inhabitants; changes in moisture in the air could show signs of reduced rainfall across much of South America, leading to water shortages in many large cities, ironically because, As a result, the farmland developed in the forest is also dry.
Food production in Brazil, Peru, Bolivia and Paraguay will be significantly affected.
For the Holocene, the Amazon rainforest ’ s best environmental service is absorbing more than 100 billion tons of carbon.
Forest wildfires that occur in each new dry season release large amounts of carbon into the atmosphere, while the reduced capacity of forest photosynthesis means less carbon is absorbed by the region each year.
The extra carbon dioxide in the atmosphere will undoubtedly accelerate the rate of global warming.
On the other side of the globe, the Arctic Sea is expected to experience its first completely ice-free summer in the 2030s, making the Arctic open water.
Even if the sea ice that has been in the safe haven for many years, the thick ice layer freezes over and over again, it cannot avoid warming and may start to disappear.
The seaweed forests that lie beneath the ice fall to the ocean floor, affecting the entire Arctic food chain.
As the Earth's ice layer decreases, the white area will gradually shrink each year, which means that the solar energy reflected back into space will also decrease, and the pace of global warming will accelerate again.
The Arctic began to lose its ability to cool the Earth.
The 1950s
Forest wildfires and melting ice over the next three decades will dramatically increase carbon emissions in the atmosphere.
As always, the surface of the sea absorbs too much carbon, and carbon dioxide will form carbonic acid after it is dissolved in the water, first at the shallow beach, then into the ocean circulation, and finally throughout the water body.
By the 2050s, the entire ocean could reach enough acid levels to cause a catastrophic decline.
Coral reefs are the most abundant of all marine ecosystems and are particularly vulnerable to acidification.
Due to years of coral bleaching, rising ocean acidity makes it harder for coral reefs to repair their calcium carbonate structure.
In this era of warmer air and intense storms, coral reefs may collapse as a result.
It is predicted that 90% of the world ’ s coral reefs will be destroyed within a few years.
The oceans are also vulnerable to acidification.
Various plankton species at the bottom of the food chain also have calcium carbonate shells. An increasingly acidified ocean will inhibit its flourishing, and fish populations throughout the food chain will suffer from it, and the harvest of oysters and mussels will begin to decline.
The rest of commercial fishing and fish farming may begin to come to an end in the 1950s, with the lives of more than half a billion people directly affected, and some source of protein that humans have been consuming will disappear from our diets.
The 1980s
By the 1980s, global food production on land may be in crisis.
In the cool and affluent regions of the world, intensive agriculture has used too much fertilizer for a century, resulting in depletion of land forces, no vitality and no harvest; while in warm and poor regions, global warming will cause temperature rise, monsoon, storm and dry season changes, making farming doomed to failure.
Millions of tons of topsoil lost around the world could enter rivers, bringing flooding to downstream towns.
If current levels of pesticide use remain high, habitat loss continues, and pollinator diseases such as bees continue to spread, the disappearance of insect species will affect three-quarters of our food crops by the 1980s.
Harvests of nuts, fruits, vegetables, and oilseeds will be greatly affected if you can ’ t rely on the diligent pollination of insects.
At some stage, the condition may worsen while another disease is endemic.
We just learned that there is a link between the emergence of new viruses and the survival of the planet, with an estimated 1.7 million potentially human viruses hiding in mammalian and bird populations.
The more we cut down forests, expand farmland, and illegally trade wildlife to destroy nature, the more likely we are to cause another outbreak of infectious diseases.
2100s
The 20th century could set off a massive global humanitarian crisis, which would be the largest forced migration in history.
In the 21st century, coastal cities around the world are expected to face a sea level rise of 0.9 meters due to the slow melting of the ice sheets in Greenland and Antarctica and the increasing warming of the oceans.
Over five decades, more than a billion of the 500 coastal cities may have been affected by storm surges, but by the 20th century, sea levels will rise enough to inundate ports and flood hinterlands.
Ports in Rotterdam, Ho Chi Minh City, Miami and other countries will not be able to withstand flooding, so they cannot take risks and become uninhabitable.
Those who were displaced had to move inland.
But there is a more serious problem.
If all of the above had happened, the Earth would be 4 degrees warmer by 2010 than it is today.
More than a quarter of the population may live in places where the average temperature exceeds 29 degrees Celsius, and today only the Sahara Desert can reach this daily high temperature.
It is impossible to farm in these areas, and a billion rural people may be forced to find a better way out.
Areas where the global climate is still milder will be under enormous pressure from population migration, where borders between countries will inevitably disappear, and conflicts may erupt around the world.
In this context, the arrival of the sixth great extinction will become overwhelming.
(Excerpt from Living on Our Planet)
【 Introduction 】
Netflix documentary of the same name
Forest fires, Arctic ice melting, torrential rain, floods, high temperatures to jump electric connection...
Is the Sixth Great Extinction Coming?
The human mind!
A 100-year-old man who wants to save young people ’ s lives tomorrow.
This is the planet we live on, and we can only protect our future on our own.
★ British National Treasure Nature Science Moderator, Historian, Witness of Earth History
★ Awarded the Order of the Lord by the Queen of England
★ IMDb top ten films, four of which are his works
Breaking the Guinness World Record with 4 Hours of IG Tracking Millions
★ Twice winner of the Emmy Award for Best Narrator
He traveled to 39 countries and photographed 650 species.
There are dozens of animals and plants all over the world named after him.
“I ’ m 95 years old, I ’ ve been making nature documentaries for over 60 years, and I ’ ve been witnessing the change of the planet all my life.
Having witnessed the decline of the earth from its beauty to its present day, and watching the oceans, wastelands, rainforests, and glaciers disappear and destroy their habitats, I will surely feel guilty if I choose to ignore them. "
After 2020, we will experience the following:
By 2030, the Amazon rainforest will be 75% less able to produce water and absorb carbon dioxide, and the Arctic Sea will have its first ice-free summer.
In 2040, the permafrost of the North melts, releasing 1,400 trillion tons of carbon dioxide and accelerating climate change.
By 2050, the oceans will absorb too much carbon leading to acidification, serious ecological damage, and reduced fish populations.
In 2080, the world is plunged into a food crisis due to overuse, exhaustion of land and failure of farming.
By 2100, the Earth's temperature had risen by 4 degrees, most areas were uninhabitable, national borders had disappeared, and wars had broken out.
The sixth great extinction is coming.
This book is the life story of David Attenborough and tells how we committed this terrible disaster, our present predicament, and our vision for the future.
But we ’ re lucky if we act now, make changes, and fix everything.
Live on our planet and make it better.
There is still time and a last chance to restore this beautiful world.
The book will teach you to take action, and what the earth needs is your will.
【 About the Author 】
by David Attenborough
In 1985, he was awarded a knighthood by the Queen of England for his contribution to the filming of natural and historical documentaries. In 2020, he was selected as one of the “Top 100 People in the UK ”.
Born in 1926, he is a natural science broadcaster and historian.
In collaboration with the BBC Natural History Unit, he has written nine comprehensive documentary films on animals and plants on Earth, four of which are ranked in the top 10 of IMBD. He won the Emmy Award for Best Interpreter in 2018 and 2019, and produced Living on Our Planet in 2020, documenting his life ’ s testimony to the Earth and his future. Attention.
> Johnny.
by Jonnie Hughes
A science writer and documentary director, he produces science and natural history films for the BBC, Discovery, National Geographic and Netflix, and has been involved in the BAFTA award-winning BBC series The Hunt and Emmy Award-winning Our Planet.
【 Translator 's Profile 】
＞ CHEN Si-wah
Graduated from the Department of Applied English at Ming Chuan University, he is interested in reading and writing, and is now a freelance translator.
# Earth # 22nd Century # Sea Level Rise # Rainforest # Extinction

Which marine organism is vulnerable to increased levels of ocean acidification?

For example, annual NOAA and IPCC reports document how reductions in Arctic sea ice and shifting plankton and fish populations, linked to acidification, have caused the timing and location of major prey blooms to change.

Which marine organism is vulnerable to increased levels of ocean acidification?

Which regions are most affected by ocean acidification?

Such changes challenge marine mammal reproductive success: gray seals, for instance, may find their preferred prey less frequently during nursing and breeding periods, threatening pup survival.

Which marine organism is vulnerable to increased levels of ocean acidification?

Similarly, whales migrating long distances may encounter fewer or less nutritious prey, observed through long-term research on feeding trends and calf survival rates in Arctic and subarctic waters .

Plankton Communities and Fisheries
Plankton, the base of marine food webs, are particularly sensitive to acidification.

Which marine organism is vulnerable to increased levels of ocean acidification?

Many important species, such as copepods and pteropods (“sea butterflies”), make shells of forms of calcium carbonate that dissolve more readily in acidic conditions.

What do shellfish use to build their shells?

Which marine organism is vulnerable to increased levels of ocean acidification?

Which ocean creatures have trouble forming shells due to ocean acidification?

Experimental work on Arctic copepods shows that acidification and warming together increase larval respiration and stress, making early life stages a “bottleneck” for population growth.

At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

Which marine organism is vulnerable to increased levels of ocean acidification?

Which regions are most affected by ocean acidification?

These plankton declines have cascading consequences: as their populations drop, food for fish, whales, and seabirds becomes less reliable, threatening the productivity of entire fisheries .

Ecosystem Changes and Compounding Stressors

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Content: There were 974 press releases posted in the last 24 hours and 451,057 in the last 365 days.

Editorial: the changing carbonate systems in coastal, estuarine, shelf areas and marginal seas

Editorial on the Research Topic
The changing carbonate systems in coastal, estuarine, shelf areas and marginal seas

Global atmospheric CO2 concentrations have increased from 320 ppm in the 1960s to the present-day value of 420 ppm, primarily due to anthropogenic activities. This increase influences the seawater carbonate system, impacting the marine ecosystem. There are still gaps that need to be resolved for predicting how these marine systems respond to current and future CO2 levels. Any actions to mitigate the change in pH will require adaptive management of multiple stressors across several spatial scales. Combined, these perspectives yield a more comprehensive picture of events during ocean acidification (OA).

This Research Topic brings together articles from different regions, including coastal, estuarine, and shelf areas and marginal seas, all susceptible to changing atmospheric conditions, riverine inputs, air-sea CO2 exchanges, and multiple acid-base reactions that can alter carbonate chemistry. Articles on the long-term trends of CO2 system descriptors and the interactions with calcifying organisms were also sought. The present Research Topic is primarily based on original articles devoted to carbonate systems in the marginal seas, but it is a pity that some interesting papers dealing with freshwater inflows, estuaries, and related coastal areas were not accepted.

Fransson et al. examined the effects of glacial and sea-ice meltwater on ocean acidification in the waters near the 79 North Glacier (79 NG) and the northeast Greenland shelf. The researchers investigated various ocean acidification factors and the influence of freshening, primary production, and air-sea CO2 exchange. One of the key findings was that the biological removal of CO2 through primary production played a crucial role in offsetting the negative impact of freshwater dilution on the aragonite saturation state (ΩAr), which is a measure of ocean acidification. This compensation effect was most pronounced in 2012, especially in the vicinity of the 79 NG front, where there was a significant presence of glacial meltwater and surface stratification. In 2016, a different scenario was observed, with a more homogenized water column due to sea-ice meltwater. In this case, the compensation effect of biological CO2 removal on ΩAr was weaker compared to 2012. The study also suggests that in the future, with ongoing climate and ocean chemistry changes, the increasing influence of meltwater may surpass the mitigating effects of biological CO2 removal. This could lead to unfavorable conditions for organisms that rely on calcium carbonate for their shells and skeletons. Thus, all the proposed factors need to be closely monitored as they could have significant implications for marine ecosystems and calcifying organisms in the face of ongoing environmental changes.

In a study by You et al., the researchers assessed ocean acidification in the Western Pacific using boron isotopic analysis in a large tropical coral core from Lanyu Islet in Southeast Taiwan. They used a well-preserved coral skeleton (Porites lobata) for detailed major and trace element analysis, including boron (B) and its isotopes (δ11B), as well as stable isotopes of oxygen (O) and carbon (C). Their primary objective was to investigate environmental changes during the period from 1991 to 1997. The coral records revealed a distinct temporal trend in sea surface temperatures (SSTs) based on elemental/calcium ratios on both annual and monthly scales. Notably, the most temperature-sensitive proxy, Mg/Ca-SSTs, indicated a significant warming trend during the study period. The researchers also observed subtle changes in the annual δ11B record, corresponding to a pH decrease of approximately 0.2 units. This change was consistent with other coral records in the Pacific, in-situ measurements of pH and pCO2, and model predictions, highlighting the impact of human-induced ocean acidification. When combined with Mg/Ca-SST data, the intra-annual coral data exhibited a clear seasonal cycle, with higher pH levels during the winter, aligning with surface ocean pCO2 patterns. These chemical and isotopic findings in corals underscore the value of marine biogenic carbonates as informative tools for reconstructing oceanic pH changes.

Rivaro et al. investigated freshwater inflow into the Ross Sea in Antarctica, particularly through the eastern gate and along the Ross Ice Shelf. They conducted a survey during the austral summer of 2019-20 to assess the contribution of Amundsen Sea Water (ASW) to salinity variations. The researchers used data on total alkalinity (AT), pH, temperature, and salinity to analyze the properties of the carbonate system, including total inorganic carbon, pCO2, and the calcium carbonate saturation state of aragonite and calcite (Ω), along with the Revelle factor. They also estimated anthropogenic carbon (Cant) using the TrOCA method to gain insights into the carbon cycle and its impact on ocean acidification due to atmospheric CO2 uptake. The study found that changes in the carbonate chemistry of surface waters were primarily influenced by physical properties. AT and pH were effective indicators of the entry of ASW, demonstrating limited mixing between different water masses in the shelf area. Additionally, shelf waters were enriched in Cant, leading to levels lower than what was estimated for shelf waters generated in the western Ross Sea.

Ingrosso et al. investigated the factors influencing the absorption of anthropogenic carbon dioxide (Cant) in the Ross Sea, an area known for its capacity to absorb carbon due to its cold waters, high primary productivity, and unique circulation on the Antarctic continental shelf. The researchers focused on the carbonate system to assess the current levels of anthropogenic carbon and understand how physical and biological processes regulate Cant sequestration along the shelf-slope continuum. They found that the Winter Water mass, formed during convective events, contained high levels of Cant due to the mixing of layers during the cold season. In contrast, the older and less-ventilated Circumpolar Deep Water entering the Ross Sea had minimal anthropogenic carbon contributions. The study also revealed variations in Cant content between different areas, such as polynyas and the shelf break, influenced by their distinct hydrographic and biological characteristics. The intense microbial activity in these regions consumed a significant portion of particulate organic carbon, leading to the release of CO2 into the intermediate and deep layers of the continental shelf zone. The findings underscored the importance of summer biological activity over the Ross Sea shelf in facilitating the transfer of anthropogenic CO2 between organic and inorganic carbon pools. This process contributed to ocean acidification in the upper mesopelagic zone and the long-term sequestration of Cant in the deep ocean.

Hassoun et al. conducted a comprehensive review of ocean acidification (OA) research in the Mediterranean region using data from the United Nations’ International Atomic Energy Agency’s Ocean Acidification International Coordination Center (OA-ICC) database and an extensive survey. Their analysis revealed several important knowledge gaps in understanding OA trends and biological impacts in the semi-enclosed and densely populated Mediterranean Sea. These gaps are attributed to disparities in OA research capabilities among Mediterranean countries and the intricate, long-term interactions among biological, chemical, and physical factors. The study highlighted an uneven distribution of OA research efforts across the region, with the Algero-Provencal and Ionian sub-basins being the least studied areas. Furthermore, the carbonate system in coastal zones remains inadequately quantified, and there is a scarcity of long-term time series data in the Mediterranean, making it challenging to assess OA trends along the coast. While certain groups of organisms, such as autotrophs (algae, phanerogams, phytoplankton), mollusks, and corals, have received considerable attention in research, others, including microbes, small mollusks (particularly pteropods), and sponges, have been relatively understudied. Despite available resources and agreements for enhanced and coordinated OA governance, there is a lack of consistent OA policies in the Mediterranean Sea. To address these challenges, the article offers recommendations based on their literature review and insights from the Mediterranean OA scientific community.

Curbelo-Hernández et al. conducted an analysis of the carbon dioxide (CO2) system, anthropogenic carbon (Cant) inventory, and air-sea CO2 fluxes (FCO2) in the waters surrounding the Macaronesian archipelago. They found that variations in CO2 levels were primarily influenced by temperature changes, biological activity, and advection processes driven by differences in the Canary Upwelling System, mixed layer depth, mesoscale activity, and circulation patterns. Surface CO2 levels (fCO2,sw) were found to be influenced by biological production and the injection of CO2-rich water in tropical waters, while temperature fluctuations played a significant role in subtropical waters. The study also examined the factors that control changes in the total inorganic carbon normalized to a constant salinity (NCT) in the upper ocean. The research revealed an increase in the uptake and storage of anthropogenic carbon compared to preexisting levels, as calculated using the TrOCA 2007 approach, which served as an upper limit for NCT. The importance of the organic carbon pump diminished in subtropical waters, while the carbonate pump had minimal contribution. Regarding FCO2, the area behaved as a CO2 sink during the winter, but strong outgassing was observed over the Cape Blanc filament. To enhance understanding in this region, the authors compared their data with existing datasets (SOCAT and GLODAP) and provided a new set of equations for calculating fCO2,sw, Cant, and FCO2 in the Macaronesian area.

All these studies emphasize the urgency of addressing ocean acidification and its multifaceted impacts on marine ecosystems. They call for continued monitoring, research, and international cooperation to better understand and mitigate the effects of rising CO2 levels on our oceans and the life they support.

Ogrinc N., Giani M. & Faganeli J., 2023. Editorial: the changing carbonate systems in coastal, estuarine, shelf areas and marginal seas. Frontiers Marine Science 10: 1325363. doi: 10.3389/fmars.2023.1325363. Article.

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The effects of ocean acidification rarely occur in isolation—they frequently amplify the impacts of other environmental threats such as warming, loss of oxygen (deoxygenation), and occasional harmful algal blooms.

What factors lead to damage of coral reefs?

For instance, research on commercial shrimp species in Kuwait demonstrated that while acidification and warming each independently reduce larval survival and growth, together they have even stronger negative effects .

At what stage of life are calcium carbonate-based organisms most vulnerable to changes in water pH?

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

How does coastal ocean acidification affect shellfish?

Dead zones and sea level rise, combined with acidification, are projected to cause the loss of fisheries and coastal habitats relied on by over 40% of the world’s population by mid-century .

Fisheries and Economic Impacts
Declining populations of shelled organisms, reduced fish survival, and shrinking plankton base directly threaten wild harvests and aquaculture.

How do scientists expect ocean acidification to impact specific fish species?

How does coastal ocean acidification affect shellfish?

How does elevated water acidity affect fish ability to survive?

Which marine organism is vulnerable to increased levels of ocean acidification?

Quantitative models indicate that by 2100, the commercial Dungeness crab fishery in the Pacific Northwest may see sharp declines linked to acidification—a vital resource for regional Indigenous and commercial communities .

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Content: There were 1,911 press releases posted in the last 24 hours and 454,773 in the last 365 days.

Evaluating the evolving ocean acidification risk to Dungeness crab: time-series observations and modeling on the Olympic Coast, Washington, USA

Evaluating the evolving ocean acidification risk to Dungeness crab: time-series observations and modeling on the Olympic Coast, Washington, USA

Published 14 November 2023 Science Leave a Comment
Tags: biological response, chemistry, crustaceans, field, fisheries, North Pacific

The Olympic Coast of Washington is home to four Coastal Treaty Tribes who have relied on the region’s rich marine resources since time immemorial. The region is characterized by large dynamic ranges of physical and biogeochemical oceanographic parameters, particularly during the upwelling season (April–September). Here, we present novel estimates of ocean acidification metrics—pH and calcium carbonate saturation states (Ω)—representing pre-industrial, present-day (using 2010 as the index year), and near-future (2030) conditions. We compare these new estimates of past, present, and near-future ocean acidification status and seasonality to published end-of-century (2100) ocean acidification projections under a high CO₂ emissions scenario, and also to sensitivity information for Dungeness crab, a regionally important subsistence and commercial fishery species projected to show strong declines in fisheries yields and revenues later this century.

Alin S. R., Siedlecki S. A., Berger H., Feely R. A., Waddell J. E., Carter B. R., Newton J. A., Schumacker E. J. & Ayres D., 2023. Evaluating the evolving ocean acidification risk to dungeness crab: time-series observations and modeling on the Olympic Coast, Washington, USA. Oceanography 36(2–3): 138–147. Article.

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How do scientists expect ocean acidification to impact specific fish species?

How does coastal ocean acidification affect shellfish?

More broadly, without intervention, major oyster and mussel fisheries could collapse as acidification progresses; this would endanger food security for over half a billion people globally .

How do scientists expect ocean acidification to impact specific fish species?

How does coastal ocean acidification affect shellfish?

Projected Future Changes
By the end of the century, projections show surface pH in the Indian Ocean and many other regions could fall below 7.7 (down from 8.1), equating to a dramatic increase in acidity.

What factors lead to damage of coral reefs?

What is the projected ocean pH level by the end of the century?

Primary productivity and chlorophyll—a measure of ocean life—could drop by 8–10% in some areas, leading to further declines across marine food webs .

Key Takeaways for Posters & Pamphlets
- Many mollusks and shellfish now have shells up to 40% thinner/smaller, with 35–40% population declines in some estuaries, threatening local fisheries .
- Cephalopods, including cuttlefish, may experience altered development and predator behaviors under acidification, especially as their prey and local ecosystems shift .
- Marine mammals such as seals and whales are impacted by prey shortages as acidification disrupts plankton and fish populations—notably in the Arctic .
- Plankton community stress lowers the base of ocean food webs, risking fisheries collapse and threatening global food supply .
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Content: Fish are becoming more suicidal due to climate change.
Archival Image
A recent scientific study revealed serious risks to fish stocks in various seas and oceans around the world, as a result of climate changes, where greenhouse gas emissions lead to increased acidity of water, prompting fish to commit suicide, attracted to large predatory fish.
The study, conducted by a team of researchers at James Cook University in Australia, aims to assess the impact of greenhouse gases that cause climate change on the coral reef area off the coast of Papua New Guinea, in the southwest Pacific Ocean, where the region is witnessing volcanic activity.
The results of the study showed that the high rate of acidity in the ocean waters, as a result of the escalation of carbon dioxide from repeated volcanic activities below the depths, leads to the loss of species of fish, on which fishing activity depends, their ability to survive, making them easy prey for other predatory species.
The study, published on the site « Nature Climate Change », that fish in general can smell the smell of large predatory species, which helps them to get off track, but surprise that in the area under study, it turns out that fish are attracted to the smell of predatory species, making them easy prey.
Lead researcher Professor Philippe Mendai said the acidity effect of the water has also been shown to cause fish to wander aimlessly into the water and go to areas far from where they live, putting them at risk, where they are more likely to be attacked by predatory fish.
The main author of the study pointed out that these threats to fish are not limited to volcanic activities, noting that about 30% of the carbon dioxide emissions in the atmosphere are absorbed by water bodies, leading to increased acidity of the seas and oceans.
The researchers also warned that the acidity levels in the coral reef area in question have reached very high levels and are expected to spread to other areas, and may include the entire Pacific Ocean by the end of this century, as the phenomenon of climate change worsens.
The study concluded that fish that live for long periods of life exposed to high levels of carbon dioxide, could not cope with the changes caused by high acidity in the water, as a result of exposure to high levels of carbon emissions permanently.
Source: News Today
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How do scientists expect ocean acidification to impact specific fish species?

Which marine organism is vulnerable to increased levels of ocean acidification?

Which regions are most affected by ocean acidification?

By 2100, some ocean regions may see pH drop below 7.7, with 8–10% primary productivity loss—a threat to ocean biodiversity and fisheries .

- Ecosystem stress is intensified when acidification is combined with warming, oxygen loss, and pollution, accelerating losses of species and habitats .

How do scientists expect ocean acidification to impact specific fish species?

Summary
Ocean acidification is a major and growing threat to marine species and entire ecosystems.

How do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

How does coastal ocean acidification affect shellfish?

How does elevated water acidity affect fish ability to survive?

What factors lead to damage of coral reefs?

While corals are often cited as the most visible victims, many less familiar but vital organisms—from tiny plankton and shellfish to iconic cephalopods and marine mammals—are also at risk.

Which marine organism is vulnerable to increased levels of ocean acidification?

These changes not only reduce biodiversity but also jeopardize fisheries, coastal livelihoods, and food security for millions worldwide.

Scientific models, field cases, and experimental studies all point to the urgent need for action to limit and adapt to ocean acidification’s impacts.