ocean-acidification

rollingstone.com
The Point of No Return: Climate Change Nightmares Are Already Here
The worst predicted impacts of climate change are starting to happen — and much faster than climate scientists expected

It is important that you understand the seriousness of this situation.  Though there is extensive coverage in print and online media, climate change gets less press than celebrity diet secrets and rap feuds.  Write to your senators and congressmen.  Sign petitions.  Organize and take part in demonstrations.  Activism is important.  

We are not going to save everything.  The world is going to change.  People are dying and will continue to die.  Property will be destroyed, possibly whole cities.  Some species will go extinct. We need to act now, and pressure our elected officials to pass serious legislation to mitigate climate change.  We don’t have to lose everything.

Sharing and liking tumblr posts isn’t enough. You must do more.

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Ocean acidification is like global warming’s sad, ignored twin. It results, like climate change, from human emissions of greenhouse gases, much of which, we know, are absorbed into the sea, lowering the water’s pH level. And while we don’t talk about it as much, the oceans have already become 30 percent more acidic over the past 200 years, with disastrous consequences for coral reefs, creatures with shells and vulnerable fisheries.

Rapid carbon emissions 252 million years ago wiped out the majority of the planet’s species. So it’s kind of a big deal.

THE HIDDEN EVIL TWIN OF CLIMATE CHANGE

According to the results of a major new national survey published by the University, the majority of the British public has a very low awareness of the issue of ocean acidification, with around only one-in-five participants stating they had even heard of the issue.

The oceans are currently absorbing large quantities of the carbon dioxide which has been emitted into the atmosphere from human activities. This absorption of CO2 is leading to a reduction in the pH of seawater – termed ‘ocean acidification’. According to the recent Intergovernmental Panel on Climate Change, ocean acidification is the hidden face of increasing global carbon emissions and poses a future threat to a range of marine ecosystems and the societies which depend upon them.

Although many other aspects of global climate change are readily recognised by the general public, we know far less about how they view ocean acidification. Researchers from the School of Psychology have conducted the first comprehensive survey of the British public’s views on this topic, interviewing over 2,500 people across the country

Very low awareness of ocean acidification:

  1. Only around 1 in 5 participants state that they have even heard of ocean acidification. Among those who do say they have heard of it, levels of self-reported knowledge about the subject are very low.
  2. Additionally, we found no significant increase in levels of awareness following the Inter-governmental Panel (IPCC) scientific reports published in April 2014.

Some people do associate ocean acidification with climate change

  1. The term Ocean Acidification itself evokes associations with pollution and negative environmental consequences. A surprisingly large proportion of those surveyed (38%) also correctly attribute anthropogenic carbon emissions as the main cause of ocean acidification, though as many again (34%) perceived that it is caused by 'pollution’ from shipping.
  2. Damage to coral reefs and consequences for marine organisms were correctly recognised by many as important consequences of ocean acidification.

Concern increases with knowledge. Distrust remains.

  1. While most people do not initially express concern about ocean acidification, once provided with some basic additional information a clear majority (64%) do then express concern about the subject.
  2. Half of those surveyed thought ocean acidification should be a fairly or very high priority for action by the British Government, although very few trust the Government to give correct information about the issue.
  • image provide by Upwell
  • more: PHYS
theconversation.com
Oceans may become too acidic for animals to smell their way around
'Smell-free seas' would be a disaster for marine life.
By Mark Lorch

The oceans are becoming ever more acidic as humans pump increasing amounts of carbon dioxide into the atmosphere. These acidic oceans will change smell molecules and render them unrecognisable for animals in the sea.

Chemical communication using smell is essential for marine organisms. Its importance is comparable to the combined status of vision and hearing in humans. My latest research reveals that smell molecules in the ocean are significantly affected by ongoing ocean acidification.

Smell molecules are chemicals that are produced by organisms either on purpose – by females to attract males, for instance – or by chance during natural processes such as protein degradation. In both cases, they can be used by animals to smell their way around.

Imagine you are a little crab living on a shore covered with large rocks and deep pools, and battered by tides and waves. The only way to find your lunchtime snack would be to smell it from a distance. But the same also applies to the octopus hunting you. So you, the crab, also rely on smelling the octopus first to avoid being eaten. What if all this were no longer possible?

Man-made, increasing carbon dioxide emissions have caused the pH in our world’s oceans to decrease, an effect called ocean acidification. By the year 2100, the sea surface pH is predicted to drop by up to 0.4 units. This may not seem much, but it has been shown to significantly affect the fitness, physiology, reproduction and behaviour of everything in the sea from huge sharks and whales to the tiniest of plankton.

Continue Reading.

SHARK PUPS MAY NOT SURVIVE CLIMATE CHANGE

Researchers find that warming ocean and acidification could hit young sharks hard. No one knew how juvenile sharks might respond to climate change until now. Scientists found that the condition and survival of young tropical bamboo sharks (Chiloscyllium punctatum) fell sharply if they developed and hatched in warmer, more acidic water. 

Acidic water affects how some ocean animals take up calcium to build their bones and shells. But without bones, sharks should have no such problems, since sharks’ muscles attach to a lightweight framework of cartilage unlike the boney skeletons of other fish.

In laboratory, researchers observed the embryos’ survival at their native temperature and pH, and with combinations of a 4° C (7° F) increase in temperature and/or a 0.5 lowering of pH. Initially, most of the shark embryos survived. But after they hatched, the young sharks’ condition deteriorated. In the group exposed to both warming and lowered pH, more than half the young sharks died within 30 days after hatching. 

The sharks may adapt over several generations. However, the long lifespans of many species and their relatively low rates of reproduction might limit how quickly they can change.

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Sea butterflies, a group of swimming sea snails, are canaries in the coal mine for the ocean. Delicately beautiful and highly sensitive to the changing oceans, these tiny creatures—most smaller than a pinky nail!—present a unique way to gauge climate. One-quarter of the carbon dioxide we release into the atmosphere dissolves into the ocean, which makes the water more acidic and makes it more difficult for these animals to build their own shells.

Scientists at the Smithsonian’s National Museum of Natural History are studying them to learn how ocean acidification will affect a wide array of ocean animals. Read our article at Smithsonian Magazine about the animals and scientists studying them—with stunning photos.

All photos © Karen Osborn (Smithsonian biologist)

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What does upwelling have to do with oyster deaths?

Our ocean is a natural carbon dioxide absorber, but with increasing pollution, one of its natural mechanisms can become self-harming.

During upwelling season, wind creates tide and wave patterns that transport water from the bottom of the ocean that naturally has higher concentration of CO2, up to the surface. Think of it like the ocean’s natural conveyor belt that makes the water at the surface more acidic certain times of the year.

The ecological effects of upwelling can be positive, but it has also been a cause in the increase in oyster mortality.

Oysters along the California coast have evolved to be very tolerant of the low pH that occurs naturally from upwelling. But researchers have found that with human-induced ocean acidification, shell-making organisms are no longer able to sustain the shells they need to survive.

Historically, pH level of the seawater has been fairly neutral, with varying amounts of CO2 existing naturally at different depths of the ocean.

But scientists have observed an overall decrease in the average pH level of the water over time since the Industrial Revolution, meaning the ocean has become more acidic and corrosive due to human activities. And this change in the chemical makeup of seawater has been dubbed “ocean acidification.”

To learn how else ocean acidification is impacting marine life, watch the most recent episode of What Oysters Reveal About Sea Change with UC Davis’ Tessa Hill to find out.

And check out The West Coast Ocean Acidification & Hypoxia Science Panel to see how scientists are working to inform policymakers about this issue.

Everything You Need to Know about Ocean Acidification

Ocean acidification has become over the last few years one of the main problems that our oceans face. Unfortunately, this issue is not visible to the naked eye, and the impacts aren’t as noticeable as increasing temperatures or sea level rise. Consequently, very few people know about it and/or care about it.

  • What is ocean acidification?

CO2 is naturally present in the air we breathe: plants need it to grow, and animals exhale it. But since the industrial revolution, the level of CO2 in our atmosphere has been increasing. Most of it ends up in the atmosphere, and hence warms up our planet. About 30% of that CO2 dissolves in the oceans, leading to chemical reactions that reduce the pH of seawater.

Over the last 10 years, scientists have realized that the excess CO2 resulting from all the anthropogenic activities has actually changed the chemical composition of our oceans. The more pH decreases, the more our oceans become acid. According to the Smithsonian, pH has gone from 8.2 to 8.1 since the industrial revolution, and they expect that it will continue to decrease by 0.3 before the end of the century. 

A decrease of 0.1 doesn’t seem like a big deal, but the pH scale is logarithmic. For example, pH 4 is 10 times more acid than pH 5. Consequently, if the CO2 emissions continue at the same rate, it is possible that the pH decreases down to 7.7, making our oceans more acid than ever. This change in only 0.1 already represents a 30% increase in the acidity of our oceans (Rhein et al. 2013). 

“Ocean acidification” thus refers to the decrease in pH caused by the increasing CO2 absorption by our oceans. 

  • What are the consequences on marine life?

A certain number of marine animals (corals, mussels, oysters etc…) use part of the carbon naturally present in our oceans to form their skeleton or shells. By trapping the carbon that way, they limit the formation of carbonic acid and thus slowly contribute against the process of acidification.

However, a more acid environment weakens these organisms that are very sensitive to changes in pH. The more acidity increases, the more energy they need to create their shells or skeletons. They become more vulnerable, using more energy to form their shells, and hence face problems with predators, feeding and reproduction.

This change in pH occurred so quickly that many animals didn’t have time to adapt, and their shells or skeletons are now slowly dissolving. A study published in 2012 in Nature Geoscience showed the corrosive effects of ocean acidification on the shells of pteropods, a small organism that is essential to the food chain.

  • Why should I be concerned?

Everything in our oceans is connected, and ocean acidification has an important impact on the food chain. Zooplankton is the base of the food chain, and is constituted of small micro-organisms that also need a shell to survive. With ocean acidification, these organisms have a hard time surviving and reproducing, and the entire food chain is at risk. 

Hundreds of species of fish, corals or sharks depend on zooplankton to live. Moreover, many nations need the oceans to thrive, as their economies are heavily based on tourism and fisheries. Food safety of these populations and global marine biodiversity are threatened by ocean acidification. 

  • What can I do?

The first step is to reduce our emissions of CO2 in the atmosphere. This can be done at the national and international level between politicians and policy makers (that is the goal of the COP21), but also at the individual and local level, where everyone can aim to use more sustainable energies. 

The exact consequences of these changes in pH are still uncertain, and a more acidic ocean is not going to destroy all the marine life. But the scientific consensus is that the 30% increase in acidity is already affecting many organisms. If acidification continues, it is possible that some species become rarer, or even extinct. 

In the next article related to ocean acidification, I will go over 5 simple steps everybody can do in their daily lives to use less energy and to help reduce CO2 emissions. Everyone can do their part in fighting ocean acidification!

Global marine analysis suggests food chain collapse

A world-first global analysis of marine responses to climbing human CO2 emissions has painted a grim picture of future fisheries and ocean ecosystems.

Published today in the journal Proceedings of the National Academy of Sciences (PNAS), marine ecologists from the University of Adelaide say the expected ocean acidification and warming is likely to produce a reduction in diversity and numbers of various key species that underpin marine ecosystems around the world.

“This ‘simplification’ of our oceans will have profound consequences for our current way of life, particularly for coastal populations and those that rely on oceans for food and trade,” says Associate Professor Ivan Nagelkerken, Australian Research Council (ARC) Future Fellow with the University’s Environment Institute.

Associate Professor Nagelkerken and fellow University of Adelaide marine ecologist Professor Sean Connell have conducted a ‘meta-analysis’ of the data from 632 published experiments covering tropical to artic waters, and a range of ecosystems from coral reefs, through kelp forests to open oceans.

“We know relatively little about how climate change will affect the marine environment,” says Professor Connell. “Until now, there has been almost total reliance on qualitative reviews and perspectives of potential global change. Where quantitative assessments exist, they typically focus on single stressors, single ecosystems or single species.

“This analysis combines the results of all these experiments to study the combined effects of multiple stressors on whole communities, including species interactions and different measures of responses to climate change.”

Read more here.

Provided by the University of Adelaide

Image: Kelp forest - Eaglehawk, Tasmania (Credit: Phil Watson)

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SHARKS LOSE SENSE OF SMELL DUE TO OCEAN ACIDIFICATION

Ocean acidification due to increased levels of atmospheric carbon dioxide concentration in oceans limits the ability of sharks to detect the smell of food, according to a recent study published in the journal Global Change Biology.

In pools with concentrations that simulate acidity levels expected by the end of the century-due to climate change, sharks spent less than 15% of their time looking for prey, in contrast to over 60% of those in pools without treatment.

Sharks are like noses swimmers, so the chemical signals are really important to them in terms of foraging

The World Meteorological Organization has just published its annual newsletter that greenhouse gases in 2013 reached record highs. These gases have a cumulative effect on ocean acidification.

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Can Washington Teach The World How To Save The Oceans?

When Alan Barton first arrived at Whiskey Creek Shellfish Hatchery in 2007, he wasn’t expecting to stay very long. The hatchery — the second-largest in the United States — was in trouble, suffering from historically high mortality rates for their microscopic oyster larvae. But Barton knew that in the oyster industry, trouble is just another part of the job.

As manager of the oyster breeding program at Oregon State University, he had already helped one oyster larvae breeding operation navigate through some tough years in 2005, when a bacterial infection appeared to be causing problems for their seeds. To combat the issue, he had created a treatment system that could remove vibrio tubiashii, an infamous killer in the oyster industry, from the water.

Ocean acidification is happening before our eyes! Scientists have long known that sea snail shells dissolve in more acidic seawater from lab experiments. But now shells have already begun dissolving from acidification in the Southern Ocean!

Photo: Courtesy of David Littschwager/National Geographic Society

(via Shell Dissolves in Seawater | Ocean Portal | Smithsonian)

Pteropods are cool, important, and in trouble.

Whaddya mean you haven’t heard about pteropods? Some marine biologists call them “the potato chips of the sea” because many other animals like to munch on them. Learn more about these sea snails with wings (YES) and how ocean acidification threatens this important strand of our local food web.

(Thanks to our colleagues over at MBARI for the video)

More on acidification, one of the most insidious ocean impacts of climate change.

The impacts of ocean acidification on coral reefs

Coral reefs are among the most dynamic and diverse ecosystems on the planet. They provide a safe habitat for hundreds of marine species, along with numerous resources necessary for the economic survival of smaller nations. Nevertheless, ocean acidification is one of the greatest threats that coral reefs face nowadays. It is now necessary to understand the problem, and to act quickly to limit the consequences potentially insuperable if coral reefs were to disappear.

  • How does a coral reef form?

Coral reefs are natural structures essentially built by hard coral colonies. Each coral is an invertebrate animal constituted of polyps. A polyp is an organism made of a mouth, stomach, wall and tentacles used for feeding and defense. Most of the corals are made of hundreds of those polyps, each genetically identical. Each polyp secrete its own exoskeleton made of calcium carbonate. Thus, hard coral species build reefs with the slow accumulation of these calcareous skeletons. Corals are furthermore considered as one of the biggest natural well of carbon on our planet.

The above video shows detailed and close-up shots of coral polyps feeding.

  • Why are coral reefs important?

Coral reefs have among the richest biodiversity on the planet, and provide ecological niches to numerous animals that find protection and food within the reef. According to the National Oceanic Atmospheric Administration (NOAA), more than 25% of the world’s marine biodiversity is found around coral reefs, as well as over 4,000 different species of fish.

Corals are also a necessity for many coastal countries. Coral reefs offer a natural barrier against erosion and flooding following strong weather events (hurricanes or typhoons, for example). Furthermore, coral reefs are of an invaluable economical importance, and supply essential goods and services such as food, raw material, water filtration, and tourism. Over 30 million people depend exclusively on those reefs for their subsistence and housing, particularly the populations living on coral islands or atolls (Wilkinson 2008).

It is difficult to calculate the exact monetary value of such an ecosystem, but according to estimations from experts at Diversitas in 2009, the goods and services supplied by coral refs have an average annual value of about $172 billion.

Originally posted by catching-like-kerosene

  • How are coral reefs threatened?

Corals are very sensitive animals, and do not tolerate big changes in their environmental conditions. They now have faced for multiple years various threats, such as overfishing, pollution, bottom trawling, warming sea surface temperatures, or ocean acidification.

It is possible that by the middle of the century, corals become incapable of surviving in numerous regions of the world due to ocean acidification, and that their dissolution will be faster than their rebuilding (Guinotte and Fabry 2008). As I explained in the first article on this topic, the more acidity increases, the more energy is required to form a skeleton, and corals thus become more vulnerable.

In 2008, Clive Wilkinson explained that the world had already lost over 20% of coral reefs. In 2011, a report from the World Resources Institute indicated that 75% of coral reefs were at risk of entirely disappearing. In July 2015, a team of international scientists lead by Dr. Jean-Pierre Gattuso of the Laboratoire d’Océanographie de Villefranche published a worrying study on the future of our oceans. If we continue with the ‘business as usual’ approach and if the CO2 emissions increase at the same rate, we can expect irreversible consequences on the marine ecosystems.

Without corals, the marine biodiversity will sharply decrease, as it will equal a huge loss of habitat, food and protection for many species. Moreover, the sectors of tourism and fisheries in numerous local and national economies will highly suffer from the disappearance of coral reefs. Finally, coastal regions will inevitably face increased beach erosion, floods, and damages in towns located close to the oceans.

  • What can we do?

All hope is not lost yet. A team of scientist has already shown that some corals are capable of regulating their own pH levels internally (McCulloch et al. 2012). Moreover, scientists in many countries, like Ken Nedimyer in Florida, have successfully established coral nurseries to grow endangered coral species (see photo), and to insure the presence of numerous and different genotypes within the reef. These corals are then transplanted onto older reef sites, previously destroyed by storms, diseases or bleaching events, so the reef can rebuild. Additionally, scientific research on corals and their resistance to such events continues across the world.

(Photo of Acropora cervicornis trees at the CRF coral nursery down in the Florida Keys. Photo by Allan Bright)

In France, l’Initiative française pour les récifs coralliens (IFRECOR), dependent on the Ministère de l’Ecologie, has been committed since 1999 to ensure the protection and sustainable management of coral reefs in French waters.

Everything in our environment is connected, and it is therefore possible to help coral reefs indirectly in our daily life. Don’t hesitate to check out the Lemonsea article on 5 things you can do to fight ocean acidification. No action is too small.

This article was originally published in French on the blog Ocean pour le Climat for Le Monde: Les impacts de l’acidification des océans sur les récifs coralliens.