Ocean acidification is a significant threat to marine life, including cephalopods, as it makes it harder for them to build and maintain their shells and skeletons.

The increase in carbon dioxide in the atmosphere leads to global warming, ocean surface warming, and sea-level rise, which can cause ocean acidification and threaten marine ecosystems, including those inhabited by cephalopods.

Cephalopods, such as pteropods, are important for the ocean environment and are affected by ocean acidification, as they have difficulty building and maintaining their shells in acidic water.

However, the search results do not provide specific information on the effects of ocean acidification on cephalopod physiology and behavior, but rather focus on other marine species such as fish, corals, and shellfish.

Ocean acidification can affect the physiology, growth, and survival of some fish, as well as change key behaviors that affect their survival chances, but the effects on cephalopods are not explicitly stated.

Some species of fish, such as the finch, have evolved significantly faster than other fish over the past 15 million years, potentially giving them greater potential to adapt to environmental changes, including ocean acidification.

The search results do provide information on the effects of ocean acidification on other marine species, such as corals, shellfish, and zooplankton, which can have cascading effects on the entire ecosystem.

For example, ocean acidification can cause a decline in the CO2 buffering capacity of seawater, which can reduce the growth performance of juvenile abalone.

Additionally, ocean acidification can affect the larval stage of marine species, such as the Eastern oyster, and can have carryover effects on the juvenile stage.

The effects of ocean acidification on marine life can be exacerbated by other stressors, such as warming and ultraviolet radiation, which can have synergistic or antagonistic effects on different species.

Ocean acidification can have significant implications for marine ecosystems and calcifying organisms, including cephalopods, and can disrupt the food chain, biodiversity, and ecosystem mechanisms.

The increase in CO2 concentrations influences the seawater carbonate system, impacting the marine ecosystem, and there are still gaps that need to be resolved for predicting how marine systems respond to current and future CO2 levels.

Seagrass meadows can act as refugia for sea urchin larvae against the negative effects of ocean acidification, and the photosynthetic activity of seagrass can increase the pH of the surrounding seawater, mitigating the negative effects of ocean acidification on calcifying organisms like sea urchin larvae.

The presence of kelp can significantly reduce ocean acidification and protect bivalves against acidification, and kelp deployment on an oyster farm can nullify ocean acidification and improve the growth of oysters.

Ocean acidification and warming can negatively affect marine species, especially those with calcium carbonate skeletons or shells, such as shrimp, and changes in water pH can affect the early stages of life for these organisms.

Overall, the search results highlight the need for further research on the effects of ocean acidification on cephalopod physiology and behavior, as well as the importance of considering the potential impacts on other marine species and ecosystems.

Collective actions, such as reducing greenhouse gas emissions, can help mitigate the effects of ocean acidification on cephalopod species.

Establishing marine protected areas and eliminating human activities that harm these areas can help protect cephalopod species from the effects of ocean acidification.

Reducing carbon dioxide emissions is crucial to preventing the demise of coral reefs, which are important ecosystems for many cephalopod species.

The cultivation of kelp can constitute an environmentally friendly means of protecting shellfisheries, including cephalopod species, against present and future ocean acidification and other coastal stressors.

Integrated culture with seaweed or increasing the seawater total alkalinity level can help mitigate the effects of ocean acidification on abalone growth, and potentially other cephalopod species, by increasing CO2 buffering capacity and calcium carbonate saturation state.

Ocean acidification and warming can negatively affect marine organisms, especially those with calcium carbonate skeletons or shells, such as shrimp and some phytoplankton species, and can disrupt the food chain, biodiversity, and ecosystem mechanisms.

Ocean acidification is a significant threat to marine life, including cephalopods, as it makes it harder for them to build and maintain their shells and skeletons.

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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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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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.

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?

What factors lead to damage of coral reefs?

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

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?

What factors lead to damage of coral reefs?

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

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?

What factors lead to damage of coral reefs?

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

The increase in carbon dioxide in the atmosphere leads to global warming, ocean surface warming, and sea-level rise, which can cause ocean acidification and threaten marine ecosystems, including those inhabited by cephalopods.

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Content: Home of the Day
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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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How do scientists expect ocean acidification to impact specific fish species?

What factors lead to damage of coral reefs?

What is the main cause of ocean acidification?

water absorbs carbon dioxide from the atmosphere

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

Cephalopods, such as pteropods, are important for the ocean environment and are affected by ocean acidification, as they have difficulty building and maintaining their shells in acidic water.

Title:

Content: Newswise — When carbon dioxide (CO2) enters the oceans, it can make the water more acidic, which is called ocean acidification. This can make it harder for some ocean creatures, like pteropods, to build and keep their shells. Pteropods are important for the ocean environment.

Pteropods are small sea creatures, including shelled sea butterflies. Not much is known about them because of their size, and they don't survive well in captivity. A team of marine scientists studied the life cycles, abundance, and seasonal changes of shelled sea butterflies in the north-east Scotia Sea, where climate change is happening quickly.

Dr Clara Manno, a researcher at the British Antarctic Survey and the corresponding author of the study published in Frontiers in Marine Science, said that the decrease in pteropod populations in the Antarctic Ocean could have significant consequences for the food web and carbon cycle. She also said that understanding the life cycle of this important organism could help to predict the impact of ocean acidification on the Antarctic ecosystem.

Population stability essential for species survival

To study the life cycle, abundance, and seasonal variability of shelled sea butterflies in the north-east Scotia Sea, a team of marine scientists collected sea butterflies in a sediment trap, a sampling device that was anchored at a depth of 400 meters. Since observing the entire life cycle of sea butterflies in a laboratory setting is impossible, the researchers had to gather information about their spawning, growth rate, and population structure. They were able to reconstruct the sea butterflies' life cycle for a year using the samples from the sediment trap.

The scientists found that the two most commonly collected species, Limacina rangii and Limacina retroversa, have different life cycles and therefore have different levels of vulnerability to changes in the ocean. During the winter months, L. rangii, which is a polar species, can be found as both adults and juveniles, while L. retroversa, a subpolar species, is only found as adults during the winter.

Sea butterflies that exist during the coldest season are more vulnerable to increased levels of ocean acidification. This is because ocean water is more acidic during this season than during other times of the year due to cooler temperatures that increase CO2 dissolution in the ocean. The researchers explained that the life stages of sea butterflies during this time are more exposed and vulnerable to the effects of ocean acidification.

L. rangii has a survival advantage over L. retroversa because both adults and juveniles coexist during winter, which reduces the risk of population instability if one cohort is vulnerable. In contrast, if one cohort is removed from L. retroversa, the entire population could be at risk.

Prolonged exposure is a survival challenge

The researchers pointed out that although the two species are affected differently, both are likely to suffer harm if they are exposed to unfavorable conditions for prolonged periods.

The scientists cautioned that the intensifying and prolonged events of ocean acidification overlap with the spring spawning period, posing a threat to the most vulnerable life stage, the larvae. This could endanger the future populations of sea butterflies.

The research team plans to further study the sea butterflies in the Scotia Sea to see how they would be affected by the increase in the intensity and duration of ocean acidification events. They will study multiyear sediment trap samples to identify potential changes in the life cycle that may occur due to environmental changes. Dr Jessie Gardner of the British Antarctic Survey, lead author of the study, said this will be the next step in their research.

Journal Link: Frontiers in Marine Science

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

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

However, the search results do not provide specific information on the effects of ocean acidification on cephalopod physiology and behavior, but rather focus on other marine species such as fish, corals, and shellfish.

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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.

Ocean acidification can affect the physiology, growth, and survival of some fish, as well as change key behaviors that affect their survival chances, but the effects on cephalopods are not explicitly stated.

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?

Some species of fish, such as the finch, have evolved significantly faster than other fish over the past 15 million years, potentially giving them greater potential to adapt to environmental changes, including ocean acidification.

The search results do provide information on the effects of ocean acidification on other marine species, such as corals, shellfish, and zooplankton, which can have cascading effects on the entire ecosystem.

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Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer

Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer

Published 10 June 2024 Science Leave a Comment
Tags: biological response, chemistry, corals, morphology

Reef-building corals live in highly hydrodynamic environments, where water flow largely controls the complex chemical microenvironments surrounding them—the concentration boundary layer (CBL). The CBL may be key to alleviate ocean acidification (OA) effects on coral colonies by partially isolating them. However, OA effects on coral CBL remain poorly understood, particularly under different flow velocities. Here, we investigated these effects on the reef-building corals Acropora cythereaPocillopora verrucosa, and Porites cylindrica. We preconditioned corals to a control (pH 8.0) and OA (pH 7.8) treatment for four months and tested how low flow (2 cm s−1) and moderate flow (6 cm s−1) affected O2 and H+ CBL traits (thickness, surface concentrations, and flux) inside a unidirectional-flow chamber. We found that CBL traits differed between species and flow velocities. Under OA, traits remained generally stable across flows, except surface pH. In all species, the H+ CBL was thin and led to lower surface pH. Still, low flow thickened H+ CBLs and increased light elevation of surface pH. In general, our findings reveal a weak to null OA modulation of the CBL. Moreover, the OA-buffering capacity by the H+ CBL may be limited in coral species, though low flow could enhance CBL sheltering.

Martins C. P. P., Ziegler M., Schubert P., Wilke T. & Wall M., 2024. Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer. Scientific Reports 14: 12757. doi: 10.1038/s41598-024-63210-9. Article.

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How does coastal ocean acidification affect shellfish?

What factors lead to damage of coral reefs?

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

For example, ocean acidification can cause a decline in the CO2 buffering capacity of seawater, which can reduce the growth performance of juvenile abalone.

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Content: There were 1,541 press releases posted in the last 24 hours and 466,409 in the last 365 days.

The effect of total alkalinity on growth performance and calcification in juvenile Pacific abalone Haliotis discus hannai

The effect of total alkalinity on growth performance and calcification in juvenile Pacific abalone Haliotis discus hannai

Published 5 October 2023 Science Leave a Comment
Tags: biological response, calcification, dissolution, laboratory, mollusks, morphology, North Pacific, physiology

A 45-day trial was conducted to study the effect of seawater total alkalinity (TA) level up- and downregulation on the growth performance and calcification of Haliotis discus hannai Ino, while seawater pH was maintained at pHNBS = 8.1. Although seawater was not acidified, the results showed that TA downregulation caused a significant reduction (P < 0.05) in the somatic tissue growth of juvenile abalone, while TA upregulation significantly increased growth performance (P < 0.05). Similar to the impacts of pH reduction, TA downregulation also induces a decline in CO2 buffering capacity, which may be the reason why somatic tissue growth was reduced, as lowered CO2 buffering capacity was reported to shift the acid-base balancing of abalone. Parts of the periostracum layer weremissing and exposed the inner shell layers of the individuals from the TA-downregulated group. Scanning electron microscopy (SEM) results showed calcium carbonate densely deposited onto the inner shell in the control and TA-upregulated groups, while sparsely deposited calcium carbonate was observed in the TA-downregulated group. The C: N ratio in the shell of individuals from the TA-downregulated group was significantly lower than that of the other two groups, indicating that less inorganic carbon was added to the shell. As a result, abalone grew lighter and thinner shells in TA-downregulated seawater. Although seawater was not acidified, TA downregulation also caused a reduction in the calcium carbonate saturation state (Ω), which induced the erosion of the surface shell and the interruption of calcium carbonate generation. In conclusion, although seawater pH remained at ambient levels, the lowered CO2 buffering capacity and Ω induced by seawater TA downregulation also showed a detrimental effect on the growth and calcification of Pacific abalone. The impact of ocean acidification on the growth of abalone should not be assessed using only seawater pH and/or pCO2 but rather taking into account all of carbonate chemistry, particularly the CO2 buffering capacity. Abalone cultivation is suggested to be carried out in seawater with a higher level of CO2 buffering capacity and Ω, which can be achieved through integrated culture with seaweed or increasing the seawater TA level.

Zhang M., Li J., Jiao M., Tang Y., Li A., Liu L., Liu L., Xue S. & Mao Y., 2023. The effect of total alkalinity on growth performance and calcification in juvenile Pacific abalone Haliotis discus hannai. Marine Environmental Research 192: 106209. doi: 10.1016/j.marenvres.2023.106209. Article (subscription required).

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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?

Additionally, ocean acidification can affect the larval stage of marine species, such as the Eastern oyster, and can have carryover effects on the juvenile stage.

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Linking physiological effects of environmental stressors from cellular to whole-organismal levels in the early-life history stages of Crassostrea virginica (eastern oyster)

The Eastern oyster, Crassostrea virginica (Gmelin, 1791), is an ecologically and economically important species that resides in dynamic coastal ecosystems along the East and Gulf coasts of the United States. The success of oyster populations depends on the recruitment of their early life stages, which are especially vulnerable to environmental stress due to high developmental energy demands. As climate change continues, it is necessary to anticipate how the early life stages of the Eastern oyster will respond to environmental stressors under ecologically relevant scenarios. Therefore, the goal of this dissertation was to understand how the early life stages of C. virginica are physiologically affected by multiple global climate change stressors from a holistic perspective by incorporating local environmental data, observations across three life stages (i.e., carryover effects), responses from two important types of Eastern oysters, and physiological metrics from the cellular to whole-organism levels. To achieve this goal, chapter two observes the relative importance of three environmental tolerance mechanisms (selective mortality, carryover effects, and phenotypic plasticity) in shaping the performance of juvenile oysters in response to salinity exposures during the larval stage. Findings from this chapter indicate that typical differences in salinity among successive larval cultures in shellfish hatcheries likely do not impact performance as juveniles; rather, phenotypic plasticity likely underpins juvenile oyster performance as their physiology correlated with environmental conditions during the juvenile phase, not the larval exposures. Chapter three investigates carryover effects in more detail to explore how multiple global climate change stressors, ocean acidification and ocean warming, might affect the physiology of larval C. virginica, if those effects carry over to impact the performance of juvenile oysters and lastly, if those carryover effects change under different future environmental scenarios. Conditions of ocean acidification and ocean warming did affect the larval stage of the Eastern oyster and carry over into the juvenile stage, though these effects were nuanced and context dependent. Specifically, carryover effects from conditions of acidification were more persistent and negative, whereas warming had more fleeting carryover, and cross-tolerant, effects that were generally positive. Continuing to observe the effects of ocean acidification and ocean warming on the Eastern oyster, chapter four compares the larval responses of wild and selectively bred oysters. C. virginica larvae from wild and selectively bred oysters responded differently to conditions of acidification, but not warming. Furthermore, wild oyster larvae may be more resilient in the face of ongoing climate change. Despite exhibiting more lethal and negative effects of acidified conditions early in the larval stage, wild oyster larvae compensated for these earlier negative effects, while larvae from selectively bred oysters began showing signs of stress towards the end of the experiment. Lastly, exploring the development of carryover effects, chapter five observes how conditions of acidification during the settlement stage (i.e., settlement and metamorphosis) carried over to impact the juvenile stage. No detectable carryover effects were found, even though conditions of acidification negatively affected tissue growth at the beginning of the settlement stage. Overall, while Eastern oysters are able to withstand environmental stress to some degree, there were sub-lethal and carryover effects from multiple global climate change stressors identified in this dissertation that could have consequences for both wild and selectively bred populations in the future. The results from this dissertation will support subsequent studies to accurately predict the future success of wild oyster populations (e.g., effects to recruitment) and aquaculture production based on their physiological performances in the face of ongoing climate change.

Schatz K. A., 2023. Linking physiological effects of environmental stressors from cellular to whole-organismal levels in the early-life history stages of Crassostrea virginica (eastern oyster). PhD thesis, Virginia Institute of Marine Science. 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 do scientists expect ocean acidification to impact specific fish species?

it will affect their physiology and growth

The effects of ocean acidification on marine life can be exacerbated by other stressors, such as warming and ultraviolet radiation, which can have synergistic or antagonistic effects on different species.

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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

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Physiological impacts of CO2-Induced acidification and UVR on invasive alga Caulerpa racemosa

Physiological impacts of CO2-Induced acidification and UVR on invasive alga Caulerpa racemosa

Published 11 March 2024 Science Leave a Comment
Tags: algae, biological response, laboratory, light, Mediterranean, multiple factors, photosynthesis, physiology

Anthropogenically increasing atmospheric CO2 causes changes in the carbon chemistry of seawater. With these changes, the HCO3 and CO2 concentration of seawater increases, while the pH decreases. CO2-induced ocean acidification by interacting with ultraviolet radiation (UVR) affects the metabolic pathways of seaweeds such as photosynthesis, growth, and nutrient uptake in a species-specific manner. This study was designed to determine the future ecological success of Caulerpa racemosa, an invasive species in the Mediterranean. In laboratory culture, C. racemosa was exposed to CO2-induced low pH (pH: 7.7) with or without UVR (UVA: 1.2 W m−2; UVB: 0.55 W m−2) and its physiological responses were investigated. Maximum quantum yield of photosystem-II (Fv/Fm) and light utilization efficiency (α) of C. racemosa was negatively affected by low pH and UVR. However, low pH increased the rETRmax (maximum relative electron transfer rate) of C. racemosa. This increased rETRmax indicated that the photosynthesis of C. racemosa was not photosynthetically saturated at the ambient inorganic carbon pool. This could be an advantage in competing with other species in the predicted future ocean acidification. The combined effect of low pH and UVR affected the rETRmax of C. racemosa in different ways along with the incubation time. The synergistic effect observed in the first two weeks turned into an antagonistic effect in the last two weeks. The data obtained from this study suggest that incubation time is the most effective factor in the response of C. racemosa to CO2-induced low pH and moderate-level UVR. In addition, our results support the hypothesis that C. racemosa may be one of the species that will benefit from CO2-induced ocean acidification.

Yildiz G., 2024. Physiological impacts of CO2-Induced acidification and UVR on invasive Alga Caulerpa racemosa. Ocean Science Journal 59: 11. doi: 10.1007/s12601-024-00136-3. Article.

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

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

Ocean acidification can have significant implications for marine ecosystems and calcifying organisms, including cephalopods, and can disrupt the food chain, biodiversity, and ecosystem mechanisms.

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

How does coastal ocean acidification affect shellfish?

What factors lead to damage of coral reefs?

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

The increase in CO2 concentrations influences the seawater carbonate system, impacting the marine ecosystem, and there are still gaps that need to be resolved for predicting how marine systems respond to current and future CO2 levels.

What factors lead to damage of coral reefs?

What is the main cause of ocean acidification?

water absorbs carbon dioxide from the atmosphere

Seagrass meadows can act as refugia for sea urchin larvae against the negative effects of ocean acidification, and the photosynthetic activity of seagrass can increase the pH of the surrounding seawater, mitigating the negative effects of ocean acidification on calcifying organisms like sea urchin larvae.

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Content: There were 1,566 press releases posted in the last 24 hours and 464,440 in the last 365 days.

Seagrass meadows as ocean acidification refugia for sea urchin larvae

Higlights

  • Sea urchin larvae were grown at ambient or low pH in tanks with or without plants.
  • Plant photosynthesis increased pH and altered seawater chemistry at both pH levels.
  • Positive effects of plant metabolism on larval development and growth at low pH
  • Seagrass meadows as a tool against climate-driven loss of calcifying species

Abstract

Foundation species have been widely documented to provide suitable habitats for other species by ameliorating stressful environmental conditions. Nonetheless, their role in rescuing stress-sensitive species from adverse conditions due to climate change remains often unexplored. Here, we performed a mesocosm experiment to assess whether the seagrassPosidonia oceanica, through its photosynthetic activity, could mitigate the negative effects of ocean acidification on larval development and growth of the calcifying sea urchinParacentrotus lividus. Sea urchin larvae at early and late developmental stages that are generally associated to benthic habitats, were grown in aquaria with or without P. oceanica plants, under ambient or low pH conditions predicted by the end of the century under the worst climate scenario (RCP8.5). The percentage of abnormal larvae and their total body length under different experimental conditions were assessed on early- (i.e., pluteus; 72 h post-fertilization) and final-developmental stages (i.e., echinopluteus; 30 days post-fertilization), respectively. The presence of P. oceanica increased mean daily pH values of ∼0.1 and ∼0.15 units at ambient and low pH conditions, respectively, compared with tanks without plants. When grown at low pH in association with P. oceanica, plutei showed a ∼23 % reduction of malformations and echinoplutei a ∼34 % increase in total body length, respectively, compared with larvae developing in tanks without plants. Our results suggest that P. oceanica, by increasing pH and altering seawater carbonate chemistry through its metabolic activity, could buffer the negative effects of ocean acidification on calcifying organisms and could, thus, represent a tool against climate-driven loss of biodiversity.

Ravaglioli C., De Marchi L., Giannessi J., Pretti C. & Bulleri F., 2024. Seagrass meadows as ocean acidification refugia for sea urchin larvae. Science of the Total Environment 906: 167465. doi: 10.1016/j.scitotenv.2023.167465. Article.

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

The presence of kelp can significantly reduce ocean acidification and protect bivalves against acidification, and kelp deployment on an oyster farm can nullify ocean acidification and improve the growth of oysters.

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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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Frontiers in Marine Science

Ocean acidification and warming can negatively affect marine species, especially those with calcium carbonate skeletons or shells, such as shrimp, and changes in water pH can affect the early stages of life for these organisms.

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?

What do shellfish use to build their shells?

What factors lead to damage of coral reefs?

Overall, the search results highlight the need for further research on the effects of ocean acidification on cephalopod physiology and behavior, as well as the importance of considering the potential impacts on other marine species and ecosystems.

Collective actions, such as reducing greenhouse gas emissions, can help mitigate the effects of ocean acidification on cephalopod species.

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

Establishing marine protected areas and eliminating human activities that harm these areas can help protect cephalopod species from the effects of ocean acidification.

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

Reducing carbon dioxide emissions is crucial to preventing the demise of coral reefs, which are important ecosystems for many cephalopod species.

What factors lead to damage of coral reefs?

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

The cultivation of kelp can constitute an environmentally friendly means of protecting shellfisheries, including cephalopod species, against present and future ocean acidification and other coastal stressors.

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

Integrated culture with seaweed or increasing the seawater total alkalinity level can help mitigate the effects of ocean acidification on abalone growth, and potentially other cephalopod species, by increasing CO2 buffering capacity and calcium carbonate saturation state.

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

it will affect their physiology and growth

Ocean acidification and warming can negatively affect marine organisms, especially those with calcium carbonate skeletons or shells, such as shrimp and some phytoplankton species, and can disrupt the food chain, biodiversity, and ecosystem mechanisms.

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

How does coastal ocean acidification affect shellfish?

What do shellfish use to build their shells?

What factors lead to damage of coral reefs?