Oceans absorb a large share of human-produced CO2, causing seawater pH to decline and acidity to rise, with acidity up 26% since preindustrial times and about 23% of annual anthropogenic CO2 taken up by the ocean.

Excess atmospheric CO2 is the main driver of ocean acidification, and its impacts extend well beyond coral reefs to many other marine species.

Aragonite saturation states are declining and are projected to drop substantially by 2100 across multiple coastal locations, threatening calcifying organisms and ecosystems.

Modeling suggests surface ocean pH could fall below 7.7 by 2100, alongside 8–10% declines in surface chlorophyll and net primary productivity that jeopardize the base of the marine food web.

Low pH dissolves calcium carbonate shells and skeletons of bivalves like clams and mussels, undermining their survival.

Harvests of oysters and mussels decline under acidification, threatening livelihoods and food security.

Abalone exposed to conditions simulating acidification show reduced growth, lighter and thinner shells, and impaired calcification when total alkalinity buffering is reduced.

Crustaceans such as crabs and shrimp are at risk because acidified waters make forming and maintaining calcium carbonate structures more difficult.

Combined warming and acidification reduce egg hatching success, increase larval mortality, and may produce smaller shrimp larvae, indicating vulnerability of early life stages.

Pteropods (sea butterflies) suffer shell damage and reduced shell-building under acidification, and their decline can ripple through the food web and carbon cycle.

Pteropod vulnerability is seasonally variable, with some species especially at risk during winter and spawning periods.

Ocean acidification can inhibit the growth of some plankton species, propagating impacts up the food chain to fish populations.

Sea urchins, widely used as reference organisms in acidification studies, show potential for acclimation and transgenerational responses, though outcomes vary by local conditions.

Seagrass meadows can locally raise pH and mitigate acidification effects, cutting sea urchin larval malformations by 23% and increasing larval body length by 34% under low pH.

Acidification alters fish physiology, growth, survival, and behavior, with high CO2 changing gene transcription in fish brains and affecting immune function.

Some fish can adapt rapidly through evolution to partially offset acidification impacts, helping maintain population size and diversity, though vulnerabilities remain.

For Pacific cod, both warming and acidification affect early life stages, with temperature the dominant stressor and the highest egg and larval mortality at the warmest conditions.

Observations also suggest acidification can cause fish to wander aimlessly, increase their risk of attack, and especially challenge long-lived fish that cannot cope with rapid changes.

In the rapidly warming and acidifying Arctic, copepod larvae increase their breathing rates, signaling potential disruptions to a keystone plankton group and the wider ecosystem.

Direct physiological effects of ocean acidification on cephalopods such as cuttlefish and octopuses were not found in the provided sources.

However, acidification-driven losses of key prey like pteropods and impacts on crustaceans and fish larvae could indirectly affect cephalopods through the food web.

Shrimp and other early life stages of crustaceans, which are part of marine food webs, are negatively impacted by the combined stresses of warming and acidification.

Ocean acidification can affect marine mammals indirectly by altering prey availability, as seen in elephant seals whose mass gain and pup production depend on access to sufficient prey.

It has also been reported that acidification can cause stress and damage to marine mammals, including embolisms, tissue damage, and temporary or permanent hearing loss.

Multiple stressors such as noise and chemical pollution can cumulatively exacerbate impacts on marine mammals’ behavior, fertility, and immune systems.

Economic and food-system consequences are already detectable in projections, with end-of-century acidification driving strong declines in Dungeness crab fisheries yields and revenues.

Nature-based and practical buffers can reduce local acidification impacts, such as adding calcium carbonate shell hash to sediments to improve pore-water chemistry and promote clam shell growth.

Kelp and seagrass can locally raise pH and protect calcifiers, with kelp cultivation shown to mitigate coastal acidification and even nullify acidification effects on some oyster farms.

Reducing greenhouse gas emissions remains essential to address the root cause, and collective actions are urged to protect ocean health.

Global commitments such as the UN Sustainable Development Goal Target 14.3 explicitly aim to minimize the impacts of ocean acidification.

Oceans absorb a large share of human-produced CO2, causing seawater pH to decline and acidity to rise, with acidity up 26% since preindustrial times and about 23% of annual anthropogenic CO2 taken up by the ocean.

Title:

Content: Sun. Nov 20th, 2022

This is a small proportion in view of conservatively projected $step one

Because the within , more than twenty four mil km2, or 17 %, off seas around national legislation (to two hundred nautical kilometers of shore) have been included in safe areas, over doubling in the the quantity since 2010

On average, one.dos percent regarding federal search finances are spent on water research between 2013 and you can 2017, having amounts anywhere between 0.02 per cent so you’re able to nine.5 %. 5 trillion contribution of the ocean towards the all over the world economy inside 2010.

Of a lot Says enjoys ratified or acceded into United nations Meeting on feeld review Rules of your Ocean (168 events) as well as using plans (150 people toward Agreement regarding the utilization of Area XI of your Us Seminar on the Rules of one’s Water and 91 functions towards United nations Fish Stocks Arrangement). Numerous Claims features followed these products thanks to court, policy and you may institutional buildings, but further advances becomes necessary in a number of developing places, particularly the least set up regions.

Waters and you can fisheries went on to help with the global population’s monetary, public and you can environment means whenever you are distress unsustainable exhaustion, environment destruction and you may carbon dioxide saturation and you may acidification. Current jobs to guard trick marine surroundings and you can quick-measure fishers and you may buy sea technology commonly yet , fulfilling the new immediate need to include that it huge, sensitive capital.

The ocean assimilates up to 23 % of your own yearly pollutants from anthropogenic carbon dioxide toward surroundings, helping to alleviate the impacts regarding weather change on the planet, although not, ultimately causing a bringing down pH and you can acidification of one’s water. A separate water acidification analysis portal suggests an increase in variability into the pH plus the acidity of one’s waters of the 10 to 31 per cent in the period 2015–2019.

The brand new sustainability off globally fishery info continues to decline, regardless if at the a diminished rates, with the ratio regarding fish stocks within biologically alternative account from the 65.8 % when you look at the 2017, down out of 90 per cent when you look at the 1974 and you may 0.8 fee area less than 2015 profile.

The new expansion away from protected elements having marine biodiversity and you can established rules and you may treaties that prompt in control entry to ocean resources are still insufficient to fight new undesireable effects regarding overfishing, increasing ocean acidification due to weather changes and you may worsening seaside eutrophication

Because the within , how many parties to the Arrangement towards Port State Procedures to get rid of, Deter and you can Eliminate Unlawful, Unreported and Unregulated Fishing – the original joining in the world agreement you to particularly needs illegal, unreported and unregulated fishing – risen to 66 (like the Eu) away from 58 in the earlier year, and you will nearly 70 % out of nations stated rating at the top of the fresh implementation thereof.

The share of alternative marine grab fisheries remained steady at around the globe height, with regional adaptation, representing the biggest contribution with the GDP within the Pacific brief isle development States and you will the very least build countries, averaging 1.55 and 1.15 percent, correspondingly, in 2011 to help you 2017.

Once the vast amounts of somebody count on oceans due to their livelihood and you may dinner source as well as on the fresh new transboundary characteristics regarding waters, improved jobs and you can interventions are needed to cut and you can sustainably have fun with water information at all profile.

  • Water acidification is caused by new consumption off atmospheric Carbon-dioxide of the the sea, and this change this new chemical substances constitution of one’s seawater. Long-label observations from ocean acidification for the past thirty years has found the typical increase from acidity regarding 26 per cent given that pre-commercial times, and also at which rates, a rise off a hundred to help you 150 % try predicted from the the termination of the newest century, having really serious effects to possess marine life.
https://atlanticfinancialmanagement.co.uk/

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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

Excess atmospheric CO2 is the main driver of ocean acidification, and its impacts extend well beyond coral reefs to many other marine species.

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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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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?

Aragonite saturation states are declining and are projected to drop substantially by 2100 across multiple coastal locations, threatening calcifying organisms and ecosystems.

Title:

Content: There were 1,570 press releases posted in the last 24 hours and 430,907 in the last 365 days.

Spatial variability of aragonite saturation state (Ωarag) in Indonesian coastal waters

Spatial variability of aragonite saturation state (Ωarag) in Indonesian coastal waters

Published 15 February 2024 Science Leave a Comment
Tags: chemistry, field, Indian, South Pacific

Highlights

  • Regional disparities reveal lower Ωarag in Pari, Lombok; higher levels in Selayar, Flores.
  • Salinity impact ranges 24.13%–52.92%, showing a negative sea surface temperature-Ωarag correlation.
  • Climate change projections for 2100 predict substantial Ωarag reduction in Indonesian coastal waters.
  • The susceptibility to ocean acidification suggests coral reefs deteriorate by 2100, except for those in the coastal waters of Selayar Island.

Abstract

The effects of Ocean acidification (OA) on the coastal waters of small islands in Indonesia have yet to be extensively studied. This research aims to investigate the process of OA in the coastal waters of small Indonesian islands and examine how land-sea interactions impact carbonate mineral saturation. We collected seawater samples from seven locations on small islands in Indonesia between 2015 and 2021 to analyze the aragonite saturation state. The result shows that most of Indonesia’s coastal waters are accompanied by supersaturation of aragonite saturation state (Ωarag>1). Selayar Island’s waters had the highest aragonite saturation, averaging 4.96 ± 0.48, while Pari Island’s coastal waters had the lowest, averaging 2.49 ± 0.50. Salinity had the greatest effect on Ωarag in all of the sampling sites, ranging from 24.13% to 52.92%, except Aceh Island, where temperature had a greater impact (34.35%) than salinity (26.99%). By the end of this century, Ωarag is predicted to decline based on projections related to climate change. Small island coastal waters are expected to experience a more substantial decline compared to those near the mainland, ranging from 4.71% to 79.58%. The coastal waters of Weh and Selayar Island are probably going to decline the greatest, while the coastal waters of Sorong (mainland) are probably going to decline the least. All seven sampling locations are expected to observe the decrease. This decline will be observed at all seven sampling locations, with Ωarag values ranging from 1.91 to 3.35.

Afdal, Bengen D. G., Wahyudi A. J., Rastina, Prayitno H. B., Hamzah F. & Koropitan A. F., 2024. Spatial variability of aragonite saturation state (Ωarag) in Indonesian coastal waters. Marine Environmental Research 195: 106377. doi: 10.1016/j.marenvres.2024.106377. Article (subscription required).

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Modeling suggests surface ocean pH could fall below 7.7 by 2100, alongside 8–10% declines in surface chlorophyll and net primary productivity that jeopardize the base of the marine food web.

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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Low pH dissolves calcium carbonate shells and skeletons of bivalves like clams and mussels, undermining their survival.

How does coastal ocean acidification affect shellfish?

What do shellfish use to build their shells?

What factors lead to damage of coral reefs?

Harvests of oysters and mussels decline under acidification, threatening livelihoods and food security.

Title:

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

How does coastal ocean acidification affect shellfish?

Abalone exposed to conditions simulating acidification show reduced growth, lighter and thinner shells, and impaired calcification when total alkalinity buffering is reduced.

Title:

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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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?

Crustaceans such as crabs and shrimp are at risk because acidified waters make forming and maintaining calcium carbonate structures more difficult.

Title:

Content: Thin fish, small catches: can Japan’s sushi culture survive climate crisis?

·5 min read

There is little at Shiogama seafood market to suggest that Japanese consumers could one day be deprived of their favourite seafood – from giant crab’s legs simmering in a winter nabe hotpot to spheres of salmon roe resting on a bed of rice wrapped in nori seaweed.

Stalls heave with huge sides of bluefin tuna, expertly transformed into more manageable portions by knife-wielding workers, while early-morning shoppers pause to inspect boxes of squid, flounder and sea pineapples landed only hours earlier.

Despite the bounty on display in this small port town, a growing body of scientific evidence – backed up by anecdotes from fishermen – points to a bleak future for Japanese cuisine as a result of the climate emergency.

Miki Seino, a Shiogama stallholder, flashes a look of weary recognition when the Observer points at her display of sanma – or Pacific saury – an autumn delicacy in Japan, where it is often served grilled or raw as sushi and sashimi.

“The catches are smaller, and the fish are thinner than they were a few years ago. We have heard about how rising sea temperatures are affecting catches here in Tohoku,” said Seino, referring to the region in north-east Japan. “And they are a lot more expensive now.”

Japan’s fisheries agency has cited changes in the marine environment due to global heating as the cause of smaller catches of saury, as well as squid, salmon and other staples of the Japanese diet.

The emergence of warm water masses in the Kuroshio – a warm north-easterly ocean current off the east coast of Japan – has pushed saury’s spawning migratory path further offshore, where food is less plentiful, resulting in depleted stocks and poorer quality fish.

Dr Aiko Yamauchi, vice-president of Seafood Legacy, a Japan-based consulting firm that supports sustainable seafood businesses and environmental groups, says catches of species venerated by the Japanese have been in steep decline since 2014.

It is possible, Yamauchi said, “that other fish species will experience poor catches similar to or worse than at present. We are very concerned that if this happens, the majority of Japanese fisheries, which supply around half of the country’s seafood, will be exposed to serious damage.”

Hundreds of miles south-west of Shiogama, fishing communities in Kochi prefecture are fretting over large catches of unusually fatty skipjack tuna, a local delicacy often eaten raw.

Kochi’s arc-shaped bay has traditionally been a fertile fishing ground, but bigger fish could be a warning rather than a blessing. The average surface temperature of the bay in winter has risen by 2C over the past four decades – meaning there is more food for the fish. But in the long term, warmer waters could spell disaster, preventing mineral-rich water from rising to the surface, resulting in fewer smaller fish to feed on – and fewer skipjack tuna.

Shin-ichi Ito, a professor at Tokyo University’s Atmosphere and Ocean Research Institute, said rising sea temperatures meant some species, including yellowtail and Spanish mackerel, were now being found in unusual locations.

“These species are being caught further north than they were 10 years ago, and this could be the result of climate change,” he said, adding that other hardy perennials of Japanese cuisine were under threat, including kelp on the northernmost main island of Hokkaido and, near the mouth of Tokyo Bay, seaweed used to make nori.

Not even sushi’s pungent accompaniment is safe, according to experts. They say the increasing frequency and severity of storms is destroying wasabi farms, while rising temperatures are threatening farmers’ ability to cultivate the delicate vegetable, which can only grow in water kept at a consistent 10-15C throughout the year.

Salmon, another sushi staple, is also at risk, Ito said. “Fish are unable to control their own body temperatures … the only option is for them to migrate northwards.” Simulations of sea temperature changes, he added, suggest that salmon could disappear from the waters around Hokkaido in Japan’s far north in a matter of decades.

“These changes will inevitably affect the Japanese diet as some species disappear, but they also mean we will see more invasive species,” he said.

A future in which crustaceans have disappeared from the menu seems unthinkable, but ocean acidification risks making that a reality. A rise in seawater temperature makes it more difficult for shellfish and crustaceans to form calcium carbonate, adversely affecting the growth of popular seafood such as scallops, clams and oysters, as well as crabs and shrimps.

“Most people can’t grasp how serious these problems are because they feel they will occur far into the future after they are long gone,” Ito said. “What happens in the year 2100 isn’t their problem … but we are at a tipping point now.”

Jun Hoshikawa has witnessed changes to the local catch first-hand from his home on Yakushima island, a Unesco world natural heritage site of natural beauty where he has lived for four decades. He is seeing fewer yellowtail, but bigger numbers of fish that used to be found further south. “The northern shift in habitats is likely to become a wider trend for many marine species as a result of rising sea temperatures”, said Hoshikawa, a former executive director of Greenpeace Japan.

“Unfortunately, most Japanese people haven’t yet noticed the subtle changes in the seafood they’re eating, although I expect that to change in the coming years.”

As mid-morning approaches, Shiogama market is filling up with regular customers and tourists who can mix and match ingredients to create their own kaisen donburi – raw seafood on rice, seasoned with soy sauce and wasabi.

The dish is a celebration of local produce that changes with the passing months. Seino, though, wonders for how long. “We are selling fish in the autumn and winter that we used to have only in the summer,” she said. “It feels like the seasons don’t matter any more.”

Reuters contributed reporting

What do shellfish use to build their shells?

What factors lead to damage of coral reefs?

Combined warming and acidification reduce egg hatching success, increase larval mortality, and may produce smaller shrimp larvae, indicating vulnerability of early life stages.

Title:

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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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

Pteropods (sea butterflies) suffer shell damage and reduced shell-building under acidification, and their decline can ripple through the food web and carbon cycle.

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?

Pteropod vulnerability is seasonally variable, with some species especially at risk during winter and spawning periods.

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

Ocean acidification can inhibit the growth of some plankton species, propagating impacts up the food chain to fish populations.

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

How does elevated water acidity affect fish ability to survive?

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

Sea urchins, widely used as reference organisms in acidification studies, show potential for acclimation and transgenerational responses, though outcomes vary by local conditions.

Title:

Content: There were 927 press releases posted in the last 24 hours and 415,878 in the last 365 days.

How do sea urchins prepare offspring to face ocean acidification? Gamete intraspecific differences and adaptability

Introduction: Due to their relevant ecological position and well-studied biology, sea urchins are reference organisms for ocean acidification studies, at both within- and trans-generational levels. In this study, we examined gamete quality in specimens exposed to future predicted (-0.4 units) pH conditions during gametogenesis.

Methods: Egg physical characteristics, biochemical composition, and fatty acid profiles were assessed after two and six months of exposure, while sperm viability and velocity were analyzed after six months of exposure. Considering the documented intraspecific variability in response to ocean acidification, this study involved two populations of Paracentrotus lividus. One population was sampled from the highly variable lagoon of Venice (Site 1), while the other was obtained from a coastal area (Site 2) characterized by more stable environmental conditions and facing minimal anthropogenic stress.

Results: A different response was highlighted in the two sites. Noteworthy trends emerged, especially in the fatty acid profile and sperm traits. Although adults were fed the same diet, Site 1 eggs contained more high-energetic fatty acids than Site 2, potentially boosting the survival odds for the next generation. Moreover, Site 1 sperms displayed higher viability but slower motility compared to those from Site 2. Within sites, a significant difference between time points and a change in the fitness strategy of sea urchin females emerged when comparing eggs spawned after two and six months of exposure to reduced pH. The effects of time and exposure pH are more pronounced in animals from Site 1, suggesting a higher adaptability of this population rather than negative effects of ocean acidification.

Discussion: Overall, our findings suggest that sea urchins have the potential to acclimate to reduced pH and to produce gametes of the same quality as controls held at the currently natural pH. Our findings emphasize the relevance of combining investigations of gamete quality characteristics, particularly egg biochemistry and fatty acid composition, and considering site variability to fully understand the transgenerational response potential of sea urchins to ocean acidification.

Asnicar D., Locatello L., Zanovello., Minichino R., Masiero L., Munari M. & Marin M. G., 2024. How do sea urchins prepare offspring to face ocean acidification? Gamete intraspecific differences and adaptability. Frontiers in Marine Science 11: 1379150. doi:10.3389/fmars.2024.1379150. Article.

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Seagrass meadows can locally raise pH and mitigate acidification effects, cutting sea urchin larval malformations by 23% and increasing larval body length by 34% under low pH.

Title:

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

it will affect their physiology and growth

Acidification alters fish physiology, growth, survival, and behavior, with high CO2 changing gene transcription in fish brains and affecting immune function.

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

How does elevated water acidity affect fish ability to survive?

Some fish can adapt rapidly through evolution to partially offset acidification impacts, helping maintain population size and diversity, though vulnerabilities remain.

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

For Pacific cod, both warming and acidification affect early life stages, with temperature the dominant stressor and the highest egg and larval mortality at the warmest conditions.

Title:

Content: There were 734 press releases posted in the last 24 hours and 394,615 in the last 365 days.

Study explores combined impacts of ocean warming and acidification on pacific cod

Newly hatched Pacific cod larva. (Image credit: NOAA Fisheries/Emily Slesinger)

As the climate changes, the ocean is simultaneously warming and acidifying. Both have been shown to adversely affect the vulnerable early life stages of Pacific cod. But until now, the interplay of these two environmental stressors was unknown.

new NOAA Fisheries study takes a look into the future by replicating predicted Alaska ocean conditions in the laboratory. The study is the first to look at the interactive effects of ocean warming and acidification on Pacific cod. Researchers evaluated the growth and survival of eggs and larvae at combinations of temperature and acidity representing current and future ocean environments. The findings can help improve predictions to ensure climate-ready Alaska fisheries and communities in the future.

Alaska Fish Face Multiple Climate-Driven Stressors

Ocean warming and acidification are escalating faster in Alaska and other high latitude regions than anywhere else on the planet. Alaska produces more than half of the nation’s wild-caught seafood. Local communities depend on the ecosystem for their livelihoods. Understanding how climate-driven stressors will affect these valuable resources is critical to ensuring resilient Alaska communities and a strong blue economy in the future.

Because fish are cold-blooded, temperature profoundly affects their growth and behavior. The effects of acidification are more nuanced. Fish can buffer acidity in the bloodstream but at an energetic cost.

Very young fish—eggs and larvae—tend to be the most sensitive stages of the fish life cycle to both warming and acidification. Unlike adult fish that can move to cooler waters, these tiny creatures are incapable of migrating to more favorable conditions. Subtle differences in their growth and condition can make a big difference to the number of young fish that make it to the adult population.

Laboratory set up for ocean acidification and ocean warming experiments with early stages of Pacific cod. Large tanks in the background provide chilled and ambient seawater that are mixed to temperature. Small round tanks house eggs and larvae at different temperatures and acidification levels. Acidification is controlled by bubbling carbon dioxide into the seawater: more carbon dioxide causes higher acidity (lower pH). (Image credit: NOAA Fisheries/Emily Slesinger)

Pacific cod is an important subsistence food, a key species in the food web, and the second-largest commercial groundfish catch in Alaska. Understanding how warming and acidification together may affect this ecologically, culturally, and commercially valuable species is key to predicting future climate impacts.

“Knowing how individual species will respond to multiple climate stressors helps us put together this puzzle to figure out what species are more vulnerable than others,” Emily Slesinger said. “And that will help guide ecosystem-based fisheries management to ensure their sustainability.”

Partnerships and Unique Laboratory Capabilities Expand Possibilities for Studying Alaska Species

Finding answers posed some hurdles. “It’s really challenging to study these fish that are found in remote and cold environments,” Slesinger said.

They met those challenges through partnerships and a specially equipped laboratory facility.

Fishermen played a key role. To obtain eggs and larvae for experiments, they first needed live adults, ready to spawn. Commercial fishermen used baited fishing pots to catch adults off Kodiak Island during the spawning season.

Fertilized eggs were shipped to the NOAA Fisheries Alaska Fisheries Science Center Laboratory in Newport, Oregon. The eggs and larvae were reared at six combinations of temperature (3°C, 6°C, 10°C) and acidification (ambient and high acidity). Scientists measured their hatch success, growth, nutritional condition, and mortality throughout the nine-week experiment.

“The Newport lab is very special,” Slesinger said. “What is most unique is our seawater system that can chill water to Arctic temperatures. The lab has the capacity to house many fish at all life stages and the expertise to keep them thriving. And it has the facilities to run these complicated experiments on the younger life stages.”

Experiments Reveal a Dominant Stressor

The study found that overall, Pacific cod’s early life stages were more sensitive to warming than to acidification:

  • Temperature affected all measured traits: growth, condition, and mortality
  • Mortality of both eggs and larvae was highest at the warmest temperature
  • 6°C was the optimal temperature for hatching, condition, and survival
  • At the warmest temperature (10°C), Pacific cod grew the fastest but were in poor condition with high mortality rates
  • At the coldest temperature (3°C), mortality rates were lower, but both growth and condition were also low
  • Acidification effects were more modest and inconsistent
  • The single instance of a negative effect of acidification was at the optimal 6°C temperature

“We’re seeing that either temperature or acidification drove the response—they were not additive. At optimal temperatures, Pacific cod may be impaired by acidification. At the warm temperature, they were overwhelmingly negatively impacted, but there was pretty much no effect of acidification,” Slesinger said. “Our findings suggest that temperature is the dominant stressor and ocean warming is likely the greater threat.”

The research highlights the complexity of species- and stage-specific responses to multiple climatic stressors and the importance of understanding them.

“This work is exciting because we are able to provide information about these fish that can be useful for future management. It is really important to me that my research can be directly helpful to societies, economies, and communities,” Slesinger said. “This research contributes to our common goal of ensuring productive, sustainable fishing into the future.”

Ecomagazine, 30 April 2024. Press release.

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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

Observations also suggest acidification can cause fish to wander aimlessly, increase their risk of attack, and especially challenge long-lived fish that cannot cope with rapid changes.

Title:

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?

it will affect their physiology and growth

How does elevated water acidity affect fish ability to survive?

fish becomes easy prey for other predators

How does increased water acidity affect fish movement?

In the rapidly warming and acidifying Arctic, copepod larvae increase their breathing rates, signaling potential disruptions to a keystone plankton group and the wider ecosystem.

Title:

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

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

Which of the world's oceans is acidifying at the fastest rate?

Which regions are most affected by ocean acidification?

Direct physiological effects of ocean acidification on cephalopods such as cuttlefish and octopuses were not found in the provided sources.

However, acidification-driven losses of key prey like pteropods and impacts on crustaceans and fish larvae could indirectly affect cephalopods through the food web.

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

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

Shrimp and other early life stages of crustaceans, which are part of marine food webs, are negatively impacted by the combined stresses of warming and acidification.

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

Ocean acidification can affect marine mammals indirectly by altering prey availability, as seen in elephant seals whose mass gain and pup production depend on access to sufficient prey.

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Marine mammal reproduction rests on a precarious tipping point of ocean resources

Changing environmental conditions may threaten marine mammal populations by making it harder to find prey, and a new study shows how small, gradual reductions in prey could have profound implications for animal populations.

The reproductive success of female elephant seals depends on their ability to find prey and put on weight during their months-long foraging migrations. Researchers at UC Santa Cruz studied the relationships between elephant seal behavioral strategies in the , , and lifetime success at producing pups.

Their findings, published March 8 in Ecology Letters, reveal a sharp threshold in the relationship between mass gain and pup production, suggesting a physiological tipping point at which insufficient mass gain leads to reproductive failure.

"We found that diving deeper during foraging allowed the females to gain more mass, and gaining more mass led to a marginal increase in their chances of survival and a massive increase in the number of pups they produced in a lifetime," said corresponding author Roxanne Beltran, assistant professor of ecology and evolutionary biology at UC Santa Cruz.

Beltran's team used 25 years of data collected by the long-running UCSC elephant seal research program at Año Nuevo Reserve to investigate the influence of and foraging success on survival and reproduction in female northern elephant seals. Biologgers carried by the seals recorded their activities during the months-long migrations, including where the seals went and the depth of their dives, while data collected on the beach at Año Nuevo told researchers which animals survived, how much weight they gained, and how many pups they had over their lifetime.

"Conceptually it makes sense that an individual would have to gain enough energy to survive and reproduce, but we were able to demonstrate how entwined these are and suggest when survival may be prioritized over reproduction," said co-first author Keith Hernandez, who worked on the study as a postdoctoral scholar in Beltran's lab at UCSC and is now at Oregon State University.

Female elephant seals give birth annually to a single pup in winter. They spend four weeks on the beach nursing their pup, relying entirely on stored energy until they can wean the pup and return to the ocean to feed. After the winter breeding season, they head out to sea for two months before returning to the colony to molt. Then they leave on a long post-molting migration, traveling thousands of miles across the North Pacific Ocean over seven to eight months.

Individual seals pursue different strategies during these foraging trips, going different distances from the coast, diving to different depths, and targeting different prey (various species of fish and squid). The researchers found that dive depth was the strongest predictor of mass gain. Deeper diving seals migrated farther from the coast and had more energy-rich diets than shallower diving seals.

The resulting mass gain directly affects a seal's ability to produce a pup. A female that doesn't put on enough weight won't give birth to a pup after she returns to the beach. The threshold is around 205 kilograms (450 pounds): animals that gained less than that rarely pupped, while those gaining more than 260 kilograms (573 pounds) almost always pupped.

Survival also depends on putting on weight, and the longer a female lives the more pups she can produce. Previous research has shown that in the long run, a relatively small number of long-lived female elephant seals produce most of the pups in the colony. These "supermoms" may live as long as 23 years and produce more than 15 pups in their lifetimes, while most females don't live nearly as long and produce many fewer pups. The strategies that allow these moms to be so successful, however, have long been a mystery.

"We discovered that an additional 5 percent of foraging success led to a 300 percent increase in lifetime pup production due to the effects of mass gain on both survival and giving birth and raising a pup each year," Beltran said. "These findings tell us which strategies allow these long-lived mammals to succeed at their most important job, which is to stay alive and contribute to the next generation."

The study also provides a framework for studying demographic trends in other species, Hernandez said.

"Determining the relationship between foraging success, survival, and reproductive success can inform effective management practices once we understand the critical periods in an animal's annual cycle," he said.

The northern population is currently doing quite well, increasing by about 4 percent each year, after being hunted to near extinction in the 19th century. At the same time, however, their ocean environment is changing due to , and the is exploring the potential of the deep "mesopelagic" zone where elephant seals find their most energy-rich prey, Beltran said.

"Open ocean fishing and climate change could both have dramatic impacts on food resources for elephant seals," she said. "Elephant seals are incredibly successful now, but that could change as their environment shifts in the coming years."

More information: Roxanne S. Beltran et al, Physiological tipping points in the relationship between foraging success and lifetime fitness of a long‐lived mammal, Ecology Letters (2023). DOI: 10.1111/ele.14193

Journal information: Ecology Letters

Citation: Marine mammal reproduction rests on a precarious tipping point of ocean resources (2023, March 8) retrieved 8 March 2023 from https://phys.org/news/2023-03-marine-mammal-reproduction-rests-precarious.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

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Shell’s seismic survey on the Wild Coast will be destructive, scientist says

Oil and gas giant Shell has controversially set its sights on the Wild Coast where it plans to use seismic blasting to hunt for oil and gas deposits in the region’s sensitive waters as early as next month.

The multinational corporation recently announced that it has appointed Shearwater GeoServices to conduct its three-dimensional (3D) offshore seismic survey from Morgan Bay to Port St Johns, which will take four to five months to complete depending on weather and current conditions.

The survey area is more than 20km from the coast at its closest point in water depths ranging from 700m and 3000m.

Shell’s survey, which will cover 6 011 square kilometres of ocean surface, has sparked outrage from marine scientists, activists and environmental organisations, who have raised alarm over the potential harmful effects of the powerful deep underwater blasts on marine ecosystems and fish stocks, the pursuit of fossil fuels and the lack of public participation, among others.

A petition by the Oceans Not Oil coalition had more than 56 000 signatures by Friday. It calls on Forestry, Fisheries and Environment Minister Barbara Creecy to withdraw the approvals for the project. But her department says neither it nor its minister were involved in giving the project the go-ahead.

The seismic vessel, the coalition says, will drag an air gun array methodically through 6 011km2 of ocean surface, firing “extremely loud shockwave emissions” that penetrate through 3km of water and 40km into the Earth’s crust below the seabed. “In the process, marine life on the sensitive Wild Coast will be panicked and damaged. Whales, dolphins, seals, penguins, sharks and even crabs and tiny shellfish will be blasted.”

The high intensity sound reaches 230 to 250 decibels. “We’re talking about massive noise in the ocean,” says Janet Solomon, of Oceans Not Oil. “It’s like a spaceship taking off.”

Blasted day and night

“Wherever seismic surveys are undertaken there’s going to be an impact, which is going to be negative,” says Dr Kevin Cole, a natural scientist at the East London Museum.

He explains that seismic surveys produce a continuous underwater noise — greater than 230 decibels — using an array of air guns day and night for months to map the seafloor and find oil and gas deposits.

This, he says, negatively affects marine life evolved to rely on sound as a primary sense in the dark oceanic environment. “Marine animals are highly sensitive to acoustic sound. Marine fish and mammals depend on sound for communicating with group members and young, food-finding, reproduction, avoiding predators and hazards, navigation and sensing their environment.”

There is no baseline research on the effects that these seismic surveys will have on the marine environment of Morgan Bay to Port St Johns, but in general they have been known to cause behavioural changes in marine life, stress, embolisms and damage to body tissue, Cole explains.

For cetaceans (dolphin and whale), “such behaviour changes involve a change in dive times and time spent at the surface and energy costs [loss of energy] having to move over large distances to get away from disturbing sounds, to name a few. Foraging and nursing may also be affected. Cetacean calves separated from their mothers because of high noise levels would be unable to suckle.”

Stress causes changes in body physiology, which may affect growth, reproduction and also result in death. The physical effects on marine animals include embolism and damage to body tissue and temporary or permanent hearing loss.

Big concerns for whales

Cole says that although it is proposed that these surveys take place out of the migratory season (May to November) for the more notable larger species such as humpback and southern right whales, there are semi-migratory and other species that will be in the survey block (December to April), which will be affected, such as the deep diving beaked whales, Bryde’s whales and sperm whales.

One of the beaked whales called True’s has never been seen alive at sea. “[It is] known only from strandings in our area so we have no clear understanding of their distribution, abundance and behaviour. This example can be applied to many other marine mammals and marine life in general ([turtles, squid and fish species in the mesopelagic zone of 200m–1 000m). Deep diving beaked whales may surface too quickly and die from barotrauma as a result of seismic blasting.”

Dr Simon Elwen, a zoologist at Stellenbosch University, says noises from seismic surveys affect “all life forms from corals and plankton to fish and whales. The biggest concerns have always been the whales as they are very acoustic animals,” he says, describing how they communicate and navigate with sound.

“A good few studies have shown behavioral impacts like changes in singing (frequency of sounds, how often they sing, loudness), multiple have shown behavioural changes like movement away from the sound source, but none to my knowledge have ever shown a clear link between seismic surveys and cetacean strandings (single, mass, whales or dolphins).”

Elwen says there have been multiple cases of strandings, mass strandings and unusual mortality events such as “linked to naval sonar, which is a very different thing”.

The best way to mitigate the effects of seismic surveys is not to do it because “we have renewables now”, Elwen says. Others include timing of the surveys in low season but  “there is no ‘no whale’ season — we have some year round” and to use observers on board to ensure no whales are close to the guns when they start. The latter two are done in South Africa to global standards, he says.

According to Liz McDaid, the strategic lead of the Green Connection, “Shell is blatantly continuing with fossil fuel exploration despite a global climate emergency … Green Connection calls on Shell to stop this and all other oil and gas-related exploration activities. We need Shell and Total and others to get real about climate change and do their part.”

‘We did consult’, says Shell

Pam Ntaka, a spokesperson for Shell, says a full stakeholder’s consultation process was undertaken in 2013 as part of the development of the environmental management programme and was aligned with the requirements of the Mineral and Petroleum Resources and Development Act (MPRDA) and environmental management programme guidelines as part of the National Environmental Management Act.

“The environmental authorisation was obtained for this project in 2014. An environmental compliance audit was undertaken in 2020 by independent specialists to confirm that the controls and mitigation measures outlined in the environmental management programme report [EMPr] were still sufficient and valid. The audit report confirmed that EMPr requirements were still sufficient and valid for this project.

Ntaka says a notification of the availability of the EMPr audit and link to download the report was sent to all interested and affected parties on the database list for a 30-day public commenting period to raise any issues or concerns. This was subsequently submitted to the government for review and approval. “Governmental approval was obtained in July 2020.”

Seismic survey effects

Ntaka says Shell is targeting a specific area within the exploration licence area “where we believe there may be potential oil or gas deposits beneath the seabed”.

A significant amount of research has been conducted globally on seismic surveys and the effect on the marine environment. “The impacts are well understood and mitigated against when performing seismic surveys. This is supported by decades of scientific research and the establishment of international best practice guidelines.”

There is no indication that seismic surveys are linked to strandings.“This can be verified through environmental specialists and the outcomes of autopsy results on stranded whales and dolphins along the coast of South Africa.”

Shell, according to Ntaka, adopts the most stringent of controls and follows international best practice from the UK’s joint nature conservation committee guidelines for conducting seismic operations. “This, in combination with the mitigation measures outlined in the environmental management programme, ensures we are conducting seismic surveys safely with regard to marine animals and the environment.”

These include an exclusion zone of 500m around the sound source that is monitored 24 hours a day by independent marine mammal observers on board the seismic vessel. “The exclusion zone around the sound source guarantees that no animals will come into the near-vicinity of the sound source.”

If any animal enters the exclusion zone, operations are shut down. “A pre-watch must be conducted for at least 60 minutes to confirm there is no marine animal within the exclusion zone before operations can commence.”

‘Threats to MPAs’

Cole says strandings are difficult to prove. “We’re actually looking at protocols to manage that better so we can get clearer data around the actual cause of death … In 2016, post the seismic surveys in KwaZulu-Natal, there were a lot of strandings. So if we had been able to have protocolos to more thoroughly dissect and interpret that, I think quite a few of them would have been put down to the effects of seismic surveys.”

He says that international guidelines such as those from the UK’s committee used for oil and gas exploration have measures proposed but these “lack a scientific basis or a proven efficacy”.

Five of South Africa’s 41 declared Marine Protected Areas (MPAs) are within the area known as the Transkei Block Exploration Right — the target area for the proposed 3D seismic surveys and exploration. Ntaka says no seismic operations will take place in MPAs and that there is a buffer area around MPAs where no seismic activities may take place.

But Cole says, “of concern is that the mitigating factors proposed such as a seismic buffer zone of 10km from the coast and 2km around the MPAs may not be effective considering the high source of sound (230 to 250 dB) and the ability of the sound to travel tens to hundreds of kilometres … It’s just ludicrous for them to think they can even think that can be accepted.

“If these habitats are destroyed in some respect, semi-permanently, it negates all efforts to have MPAs declared when you have a five-month seismic survey coming in and chasing a fossil fuel and all those questions are in the air.”

Environment department ‘not involved’

According to the department of forestry, fisheries and the environment (DFFE), in or during 2013, Impact Africa Limited applied for exploration rights in terms of the MPRDA, which was granted by the minister responsible for the department of mineral resources and energy or his delegate in terms of the MPRDA.

“The department … and the minister responsible for the DFFE, were not involved in any aspect of this decision making process, including the environmental impacts thereof, particularly as the application process was finalised prior to the coming into effect of the one environmental system that came into effect on 8 December 2014.”

Shell has since acquired Impact Africa’s exploration rights. The mineral resources and energy department referred the Mail & Guardian to Creecy’s department.

According to Oceans Not Oil, in 2014 the legislation imposing environmental impact assessments (EIAs) for seismic surveys “fell out of our law due to enabling amendments made by the government’s one environmental plan for offshore Operation Phakisa. The rationalisations of environmental laws between the minerals and energy departments and the environmental one has a consequence of a big omission of care and precaution when dealing with seismic surveys.”

It, too, meant the “lubrication” of entry of Big Oil onto the coastline as EIAs take time, money and require input from affected people. “Public pressure has since placed seismics back into legislation that insists on public participation and environmental reports to guide the process.”

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Sheree Bega
Sheree Bega is an environment reporter at the Mail & Guardian.

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

Multiple stressors such as noise and chemical pollution can cumulatively exacerbate impacts on marine mammals’ behavior, fertility, and immune systems.

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The hidden ocean pollution killing marine mammals
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Noise and chemical pollution in our oceans are affecting marine mammals' ability to navigate, communicate and detect danger.
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I've worn glasses since the age of five, my hearing isn't brilliant in busy environments and, like many others, I lost my sense of taste during Covid-19, which was incredibly disorientating. Perhaps once our senses are pushed to their limits, we begin appreciating them all the more. But we're certainly not the only ones relying on multiple senses: marine mammals depend on them to communicate, navigate, feed, hear and detect danger.

It's hard for us to imagine how marine creatures sense within their world. What's clear is that the picture is complex, and that human-induced impacts make that even more challenging.

Pollution is ubiquitous but not homogenous. There is oil and gas exploration on the seabed, military exercises, increasing shipping traffic and the relatively new threat of deep sea mining. Add to that sewage outflows, industrial discharge and agricultural run-off, the marine environment is getting busier, noisier and more polluted. So what are the hidden dangers to marine life?

As a marine strandings volunteer for the Devon Wildlife Trust in south-west England, I'm regularly asked to take photos and measurements of marine mammals stranded along my local coastline. Sometimes, there'll be noticeable injuries, rake marks from the teeth of bottlenose dolphin attacks perhaps, long straight cuts in the skin from a fishing line or occasionally a tail clean cut off as a result of bycatch. Usually though, the actual cause of death isn't simple to identify. A crack team of scientists are on a mission to discover more about how human-induced impacts affect UK populations of whales, dolphins and porpoises.

To find out more about their research, I visited Rob Deaville, a strandings scientist at the UK Cetacean Strandings Investigation Programme, this summer. Every year, he dissects about 150 stranded porpoises, dolphins and whales to find out what might have killed them. "In some cases, it can be very evident, for example bycatch, ship strike, grey seal predation, bottlenose dolphin attack, those causes of death are really obvious. But even a high level of pollution is not necessarily causal in an animal's death, it's more associated," says Deaville. "You're looking through a keyhole at one aspect, at what I call the terminal end, and then trying to look backwards at what that animal has experienced throughout their lifetime.

"High noise pollution or limited prey availability, climate change, chemical pollution all those things have an impact – it's hard to tease that apart for any single individual pressure," he says.

Marine mammals depend on their senses to communicate, navigate, feed, hear and detect danger

Watching Deaville deconstruct this porpoise was a fascinating biology lesson in itself. But more than that it highlighted just how much these creatures can reflect their marine environment and how they live within it. From the parasitic worms living in their lungs, guts and liver to the delicate fish bones found within one of porpoise's three stomachs, every insight is valuable.

But the most crucial of all, Deaville tells me, is the sample of blubber, that fatty layer just beneath the skin, that he cuts from just by the base of the dorsal fin. It's about an inch thick and acts as a ledger – Deaville will send it off for pollutant analysis by expert toxicologists. This helps build a picture of some of the less visible impacts that may be affecting marine life and potentially contribute to their death.

I set out to investigate how the less visible forms of human-induced pollution – both chemical and acoustic – could affect the senses and survival of porpoises, dolphins and whales, and discovered that there's a lot going on beneath the waves.

Super senses

"For whales and dolphins, 'listening' is as important as 'seeing' is for humans, as they live in a world of water and sound," says Danny Groves, communications manager at the non-profit Whale and Dolphin Conservation. He adds that the impacts of human-induced disturbance on cetaceans are "huge".

"Noise pollution threatens whale and dolphin populations, interrupting their normal behaviour, driving them away from areas important to their survival [for breeding, socialising and feeding] and at worst injuring them or sometimes even causing death," he says. Natural impacts such as earthquakes and lightning strikes also make big, sudden noises but tend to be more intermittent.

Toothed whales, a group that includes narwhals, dolphins and porpoises, hunt using echolocation or biosonar. They hear at high frequency ranges. Baleen whales hear at lower frequencies, and may be more affected by shipping noises as a result.

A porpoise autopsy revealed just how much these creatures can reflect their marine environment (Credit: Alamy)

There's more to sound than just noise though. Joy Reidenberg, a professor who studies whale anatomy at Mount Sinai in New York, explains that sound acts as a pressure wave. "Wherever in the body there are air-containing spaces, those can compress, then overexpand as a whale dives and ascends but if tissues can't deform accordingly, they'll rupture," she says. Seismic surveys – used to pinpoint deposits of oil and gas in the seabed – are incredibly intrusive, loud booms of sound. "I'm pretty sure the whale would feel that as a pressure wave moving through their body and also as a sound that they can hear. So there is a tactile aspect to hearing that we often overlook." How much of that pressure is felt by the skin is unknown.

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Chemoreception, that includes both smell and taste, could play a significant role too. Reidenberg explains that baleen whales can possibly smell, while some whales have taste receptors on their tongues but that it's not yet clear what exactly they are detecting. "They tend to swallow prey whole so maybe they are tasting the water to detect when they get close to prey or sensing salinity which may help them navigate," says Reidenberg. "It's even possible that narwhals could sense salinity through the sensitive pores in their tusk – that could be a really important sense."

DO WHALES HAVE WHISKERS?

Baby whales rely on whisker sensation "to help them figure out where the nipple is so they can nurse," says Reidenberg. Whiskers are usually lost by the time these animals become sexually mature, but in some toothed whales, 'pits' remain where the whiskers were.
In some species of dolphins, it has been shown that these pits have the anatomy of electrical sensors.

"So some dolphins plunge their faces into the sand of the seabed and do this spiral manoeuvre with their bodies, possibly detecting the electromagnetic field of a fish buried in the sand," says Reidenberg. Besides detecting prey, she says that hairs could be used to sense water currents flowing past, to indicate when an animal has reached the surface to breathe, or to detect friendly or aggressive encounters from other animals.

Whale vision is "much better than we'd expect it to be," says Reidenberg, though some species rely on it more than others. Indus and Ganges river dolphins are functionally blind because their murky habitat precludes them needing to see. Orcas, on the other hand,spy-hop out of the water when hunting seals and have relatively good eyesight.

An industrialised ocean

Research suggests that all these ways of sensing are being impaired by human activity.

For whales, dolphins and porpoises, both chemical and acoustic pollution affect the way their bodies can function in many ways. Some effects are immediate and acute while others are more long-term and chronic. Besides impacting their senses and ability to communicate, marine pollution can impair their fertility and immune systems.

Thomas Goetz, an expert in bioacoustics at the University of St Andrews in Scotland, studies how marine mammals are affected by human-generated noise and how sound can be used to keep animals away from harm. He explains why context is key: "To really understand the effects of a pollutant, you really need to understand the physiology of this animal, of the sensory systems for each species." Each pollutant in a cetacean's habitat can have different effects. "There's unfortunately no way around looking in real detail and accepting the complexity of it…because they have all evolved very different sensory organs and their perceptual worlds differ," says Goetz.

Acoustic pollution can hinder communication and echolocation sounds, change an animal's behaviour and elevate stress levels. For North Atlantic right whales, low-frequency noise from big ships can result in an increase in stress-related chemicals linked to growth suppression, reduced fertility and poor immune system function. That chronic stress is having a physiological impact.

Sudden and acute impulsive noise in the marine environment might lead to ear trauma haemorrhage, while more chronic exposure from the constant low-level whirr of a shipping lane nearby could perhaps shift its behaviour patterns and make communication or feeding more difficult. Deep-diving whales and dolphins can also suffer from decompression sickness or 'the bends' when they surface too quickly. Over time legions or tears in the internal tissue form due to nitrogen bubble formation, but it's hard to conclude whether that happened due to natural causes or human-induced noise.

"Different species are more sensitive to sound than others," says Deaville, who motions towards the Cuvier's beaked whale tooth on the desk in front of him. "That's the deepest diving cetacean species, it holds its breath for nearly three hours, dives down to 3000m (9843ft) in some instances and is really operating at the edge of what is physiologically possible," he says. "That's perhaps why they are more sensitive to noise disturbance - most of these mid-frequency sonar navy-related mass strandings involved beaked whales, particularly Cuvier's. So I suspect if they dive down as deep as they possibly can they're more at risk of coming to the surface too quickly and getting into conditions that might be problematic."

Scientist Maria Morrel at the University of Veterinary Medicine in Hanover, Germany, is studying the ears and ear bones from stranded toothed whales such as pilot whales and developing a protocol to assess loss of hearing in whales. Once stabilised in formalin to preserve the sample, she analyses the ear using a scanning electron microscope and has noticed that the loss of the tiny hair cells and membrane scarring within the inner ear may indicate loss of auditory function. But when that hearing loss happened exactly and what caused it remains unknown.

SENSORY OVERLOAD

From the microplastics sprayed on farmland to the noxious odours released by sewage plants and the noise harming marine life, pollutants are seeping into every aspect of our existence. Sensory Overload explores the impact of pollution on all our senses and the long-term harm it is inflicting on humans and the natural world.

According to Reidenberg, military sonar pulses act like a sound bomb and certain frequencies could result in decompression sickness. The US Navy, she adds, does its best to protect marine wildlife: "Sonar is well-regulated but in wartime those regulations are lifted – the navy is making extraordinary efforts to tag, track and monitor whales to protect them from sonar exercises."

That said, military operations in Europe have been implicated in mass cetacean deaths. When 85 harbour porpoises stranded along 100km (62 miles) of Danish coastline within one week of each other during April 2005, bycatch was initially established as the cause of death for most, due to net markings on their skin and the loss of tail flukes. Local fishermen confirmed that porpoise bycatch was much higher than usual in nets that had been set to catch lumpfish. Further investigation revealed military ships in the area that week, en route to a huge naval exercise.

In a study, Andrew Wright, a marine mammal researcher from Aarhus University in Denmark, concluded that while the use of sonar cannot be confirmed, it certainly cannot be ruled out as a contributing factor to increased bycatch rates. Perhaps sonar resulted in more porpoises being driven away from the noise towards nets, or perhaps disturbance masked their ability to detect the static fishing gear, he said. As Deaville states, "these things stack up in combination".

That highlights the problem – it's impossible to disentangle every effect.

Besides impacting their senses, marine pollution can impair mammals' fertility and immune systems

Deep-sea mining could also cause severe disturbance, according to new research. Marine researchers estimated that noise from just one mine on the seabed could travel approximately 500km (311 miles) through the water column in gentle weather conditions. In places where multiple mines might operate, the cumulative effect of acoustic pollution could be far greater. Because seabed mining companies have not yet shared their data on noise pollution, this study used noise levels from well-studied industries such as oil and gas industry ships and coastal dredges to model 'conservative' estimates.

The actual seabed mining equipment is far larger and more powerful than the proxies, the experts say. One of the study co-authors, Christine Erbe, a professor in underwater acoustics at Australia's Curtin University, says: "Estimating the noise of future equipment and installations is a challenge, but we don't have to wait until the first mines are operational to discover the noise they make. By identifying the level of noise in the engineering design phase, we can better prepare for how this might impact marine life."

In the Arctic, narwhals – deep-diving whales with the long, protruding unicorn-like tooth – live relatively far from human activity. But as the ice melts, more shipping routes are opening up through this region and oil and gas exploration is increasing. Scientists from the University of California have recently found that when narwhals in Greenland were exposed to seismic air guns (oil and gas survey instruments which produce high-intensity sound bursts), they immediately began diving quickly down from the surface. Normally, they'd glide down to conserve energy, but this speedy escape tactic is affecting how much blood and oxygen circulates in their body. It also distracts from other behaviours such as feeding, according to data collected using monitoring tags.

Rather than having to cope with one threat a time, marine mammals experience the combined pressures of multiple forms of pollution (Credit: Francois Gohier / Getty Images)

All of these invisible pollutants need to be taken into account. Hanna Nuutila, a marine ecology researcher at Swansea University, Wales, says it's vital to appreciate the cumulative effect of different stressors and pathways to disturbance. "Disturbance is both physical such as in-water structures (that includes every single coastal and offshore construction from oil and gas platforms to windfarm piles, harbours and marinas, and renewable energy structures) but also mobile in terms of ships, ferries, tankers and luxury cruisers," she says. She adds that all marine renewables are having to undergo much more detailed scrutiny in terms of impacts on wildlife than oil, gas and nuclear ever did.

"Obviously fishing too causes not just entanglement but also decreasing prey availability. All these tend to have a noise effect as well while most also leak oil, organic waste or chemicals into the sea." Nuutila emphasises the need to create designated safe zones free from human disturbance and the Marine Mammal Protected Areas Task Force runs a global initiative to create just that, in the form of Important to Marine Mammal Areas.

Swimming in a toxic soup

Toxic, synthetic chemicals are perhaps one of the most insidious forms of pollution entering the ocean. The worst culprits are persistent organic pollutants (POPs) that don't break down easily and are lipophilic or fat-loving; they end up in the blubber of porpoises, dolphins and whales. One particularly toxic legacy contaminant – so-called because it's still causing problems decades after being banned – is a class of 209 industrial chemicals known as polychlorinated biphenyls or PCBs. Invented in the 1920s, they  were used in machinery coolant, electrical goods, flame retardants, paints and building sealants. Although banned globally more than 40 years ago, they linger in landfills and escape into the marine environment.

Deaville explains why PCBs are so concerning: "They work in two ways, they affect the immune system, so [animals] might have lots of secondary diseases because [their] immune system is basically knackered and more insidiously they also affect reproduction so in highly PCB-exposed populations there'll be a drop-off in young animals being born.

"A population of whales might not have a calf for a long time even though they should be reproductively active – that to us would be a red flag and indicate potential PCB exposure."

In 2016, an orca known as Lulu was found dead on the coast of the Isle of Tiree, the most westerly island of the Inner Hebrides in Scotland, after becoming entangled in fishing gear. A post-mortem of her body found that her body contained extremely high levels of PCBs (100 times the toxicity threshold for PCBs in marine mammal blubber) and scientists concluded that she was one of the most contaminated animals on the planet in terms of PCB burden. On examination of her ovaries, the scientists at the Scottish marine animal stranding scheme found no evidence of her ever having been reproductively active.

Industrial chemicals known as PCBs linger in landfills and escape into the marine environment, damaging mammals' reproductive systems (Credit: Robertus Pudyanto / Getty Images)

Throughout any animal's lifetime, exposure to pollutants changes from place to place and from time to time. Exposure impacts different species to varying degrees too. Orcas tend to live for longer than porpoises, for example, so they have more time to accumulate chemical pollutants in their bodies. They also feed at a higher level within the food chain, so they are eating bigger fish and other marine mammals which themselves contain contaminants. Deaville explains that POPs are stored within the blubber. When an animal's nutritional state deteriorates, either seasonally or as a result of illness perhaps, those toxic contaminants are released into the blood as the fat layer thins. Toxic chemicals are also passed on to calves via breast milk and so a mother can unwittingly offload toxic pollution onto a firstborn calf, sometimes resulting in death.

Rosie Williams, a toxicologist who works alongside Deaville, found in a 2021 study that high levels of PCBs in blubber samples from 267 stranded harbour porpoises are associated with reduced testicle size in male harbour porpoises. These pollutants are having a direct impact on fertility and potentially affecting the future breeding success of the species. PCBs are also known to suppress the immune system so porpoises with higher contaminant levels are more likely to die from infectious disease

Of course, marine mammals are not experiencing just one chemical at a time. Since it began in 1990, the UK Cetacean Strandings Investigation Programme has carried out more than 4000 necropsies on porpoises, dolphins and whales and tested for a wide range of pollutants, from the widely known banned pesticide DDT to anti-foul paint residues and flame retardants added to textiles. "An animal may be living in a heavily fished area, with lots of bycatch, less prey, heavily contaminated, lots of noise, all those things are happening in tandem all at once – that's how the animal lives its life," Deaville says. "There's a cumulative impact. It's a complex thing to get a handle on."

In the case of the stranded porpoise being dissected in the lab, chemical pollution may well have played a part. In a few months' time, toxicology reports will show more about its specific chemical burden. Ultimately, for Deaville and Williams, it's about noticing changing trends, which could then inform policy and change how pollutants are managed. Plastics are high up on the agenda too – a 2019 study by the University of Exeter found microplastics within all 50 marine mammals sampled that had stranded on UK shores. As yet, the actual impacts of those plastic particles on cetacean survival remains inconclusive.

Experts say that rather than having to cope with threats one at a time, animals experience the combined pressures of multiple forms of pollution within the marine environment. Marine mammals are living in a "soup" of pollution issues, says Deaville. The effects change depending on location or depth, and the animals' season or stage of life, he adds.

So much of the damage and disturbance human activity causes is accidental and preventable, says Tom Mustill, filmmaker and author of a new book called How to Speak Whale. By designing things differently and considering how something might affect other animals, especially whales and dolphins that use such sophisticated communication, we can drastically reduce those negative consequences, he says. Enforcing speed limits on shipping vessels could drastically reduce collisions, for example – on the east coast of the US, proposals to introduce 'dynamic speed zones' could help protect endangered North Atlantic right whales in areas where these marine mammals are detected.

Slower ship speeds give the animals more time to adapt their navigation accordingly and reduce the risk of ship strikes. "This science of discovering what the sensory lives of these animals are like, how they perceive the world and how they communicate within it, allows us to understand how we might impact that and modify our impacts to that. That could be transformative," says Mustill.

As stomach-wrenching as this porpoise post mortem was to witness, it's clear that each stranding provides scientists with invaluable insight into how these cetaceans live and die, and how our actions are impacting them. The next step is to adapt strategies and policies accordingly so that by reducing pollution, marine wildlife and ocean health are better protected.

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Economic and food-system consequences are already detectable in projections, with end-of-century acidification driving strong declines in Dungeness crab fisheries yields and revenues.

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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?

Nature-based and practical buffers can reduce local acidification impacts, such as adding calcium carbonate shell hash to sediments to improve pore-water chemistry and promote clam shell growth.

What do shellfish use to build their shells?

Kelp and seagrass can locally raise pH and protect calcifiers, with kelp cultivation shown to mitigate coastal acidification and even nullify acidification effects on some oyster farms.

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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Frontiers in Marine Science

Reducing greenhouse gas emissions remains essential to address the root cause, and collective actions are urged to protect ocean health.

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.

Global commitments such as the UN Sustainable Development Goal Target 14.3 explicitly aim to minimize the impacts of ocean acidification.

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Content: There were 1,357 press releases posted in the last 24 hours and 396,480 in the last 365 days.

Integrated actions across multiple sustainable development goals (SDGs) can help address coastal ocean acidification

Integrated actions across multiple sustainable development goals (SDGs) can help address coastal ocean acidification

Published 17 June 2024 Science Leave a Comment
Tags: policy, review

The Sustainable Development Goals (SDGs) adopted by the United Nations in 2015 constitute a set of 17 global goals established as a blueprint for achieving a more sustainable and equitable world for humanity. As part of the SDGs, target 14.3 is focuses on minimizing and addressing the impacts of Ocean Acidification (OA). We argue that moving forward in meeting the targets related to pH levels in the coastal ocean can be facilitated through accounting for various drivers of pH change, which are associated with advancing a suite of SDG goals. Addressing ‘coastal acidification’ via a suite of linked SDGs may help avoid inaction through connecting global phenomena with local impacts and drivers. This in turn can provide opportunities for designing novel place-based actions or partnerships that can aid and provide synergies for the joint implementation of programs and policies that tackle a suite of SDGs and the specific targets related to coastal ocean pH.

Vargas C. A. & Gelcich S., 2024. Integrated actions across multiple sustainable development goals (SDGs) can help address coastal ocean acidification. Communications Earth & Environment 5: 319. doi:10.1038/s43247-024-01485-6. Article.

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