ocean-acidification

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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
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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)

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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Hundreds of millions of people gather marine life threatened by changing seas. But the Indonesian village of Sampela depends so thoroughly on troubled coral reefs that climate change and shifting sea chemistry eventually could make it challenging to find food.

This slideshow is from “Sea Change,” an in-depth multimedia series on ocean acidification and climate change produced by The Seattle TimesSee the full presentation of articles, pictures, graphics and video.

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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.

New Algae Species Helps Coral Stand the Heat

It’s no secret that the world’s coral reefs are rapidly declining, taking the one-two punch that is warming temperatures and mounting ocean acidification. However, there is hope, and it’s coming straight from an unknown member of the natural world. Researchers have just discovered a new species of algae, and it’s one that seems to be able to help corals survive otherwise deadly temperatures.

That’s at least according to a study recently published in the journal Scientific Reports, which details how a previously unknown species of algae (Symbiodinium thermophilum) found in the waters of Abu Dhabi, of the United Arab Emirates, is what likely facilitates what is the warmest known coral reef habitat.

Continue Reading.

Rate of environmental degradation puts life on Earth at risk, say scientists

Humans are ‘eating away at our own life support systems’ at a rate unseen in the past 10,000 years, two new research papers say


The view from the Amazon Tall Tower Observatory in the middle of the Amazon forest. Researchers say that of the nine processes needed to sustain life on Earth, four have exceeded “safe” levels.

Humans are “eating away at our own life support systems” at a rate unseen in the past 10,000 years by degrading land and freshwater systems, emitting greenhouse gases and releasing vast amounts of agricultural chemicals into the environment, new research has found.

Two major new studies by an international team of researchers have pinpointed the key factors that ensure a livable planet for humans, with stark results.

Of nine worldwide processes that underpin life on Earth, four have exceeded “safe” levels – human-driven climate change, loss of biosphere integrity, land system change and the high level of phosphorus and nitrogen flowing into the oceans due to fertiliser use.

Researchers spent five years identifying these core components of a planet suitable for human life, using the long-term average state of each measure to provide a baseline for the analysis.

They found that the changes of the last 60 years are unprecedented in the previous 10,000 years, a period in which the world has had a relatively stable climate and human civilisation has advanced significantly.

Carbon dioxide levels, at 395.5 parts per million, are at historic highs, while loss of biosphere integrity is resulting in species becoming extinct at a rate more than 100 times faster than the previous norm.






Since 1950 urban populations have increased seven-fold, primary energy use has soared by a factor of five, while the amount of fertiliser used is now eight times higher. The amount of nitrogen entering the oceans has quadrupled.

All of these changes are shifting Earth into a “new state” that is becoming less hospitable to human life, researchers said.

“These indicators have shot up since 1950 and there are no signs they are slowing down,” said Prof Will Steffen of the Australian National University and the Stockholm Resilience Centre. Steffen is the lead author on both of the studies.

“When economic systems went into overdrive, there was a massive increase in resource use and pollution. It used to be confined to local and regional areas but we’re now seeing this occurring on a global scale. These changes are down to human activity, not natural variability.”


View of aluminium-polluted water, which flows into the Yuanjiang River, in Taoyuan county, Changde city, central China’s Hunan province, 19 November 2014. Photograph: Imaginechina/Corbis

Steffen said direct human influence upon the land was contributing to a loss in pollination and a disruption in the provision of nutrients and fresh water.

“We are clearing land, we are degrading land, we introduce feral animals and take the top predators out, we change the marine ecosystem by overfishing – it’s a death by a thousand cuts,” he said. “That direct impact upon the land is the most important factor right now, even more than climate change.”

There are large variations in conditions around the world, according to the research. For example, land clearing is now concentrated in tropical areas, such as Indonesia and the Amazon, with the practice reversed in parts of Europe. But the overall picture is one of deterioration at a rapid rate.

“It’s fairly safe to say that we haven’t seen conditions in the past similar to ones we see today and there is strong evidence that there [are] tipping points we don’t want to cross,” Steffen said.

“If the Earth is going to move to a warmer state, 5-6C warmer, with no ice caps, it will do so and that won’t be good for large mammals like us. People say the world is robust and that’s true, there will be life on Earth, but the Earth won’t be robust for us.

“Some people say we can adapt due to technology, but that’s a belief system, it’s not based on fact. There is no convincing evidence that a large mammal, with a core body temperature of 37C, will be able to evolve that quickly. Insects can, but humans can’t and that’s a problem.”

Steffen said the research showed the economic system was “fundamentally flawed” as it ignored critically important life support systems.

“It’s clear the economic system is driving us towards an unsustainable future and people of my daughter’s generation will find it increasingly hard to survive,” he said. “History has shown that civilisations have risen, stuck to their core values and then collapsed because they didn’t change. That’s where we are today.”

The two studies, published in Science and Anthropocene Review, featured the work of scientists from countries including the US, Sweden, Germany and India. The findings will be presented in seven seminars at the World Economic Forum in Davos, which takes place between 21 and 25 January.

Source:- http://www.theguardian.com/environment/2015/jan/15/rate-of-environmental-degradation-puts-life-on-earth-at-risk-say-scientists?CMP=share_btn_fb

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The Phytoplankton Emiliania huxleyi
Coccospheres up close and personal
IMAGES: Natural History Museum, BBC, Rutgers/Woods Hole

Like other coccolithophores, Emiliania huxleyi is a single-celled phytoplankton covered with uniquely ornamented calcite disks called coccoliths (also informally known as liths or scales).  [WP]

  • It is one of the youngest species on Earth, appearing only around 250,000 years ago, about the same time as Homo sapiens.
E. huxleyi has a global population of about 7 x 1022 cells scattered across the world ocean and adapted to a wide range of environments.
  • It can grow explosively to produce massive blooms of milky water detectable from space.
  • It has a Cheshire Cat-like ability to escape from trouble by changing form.
    [Source: Natural History Museum, London]

BOTTOM IMAGE: Scanning electron microscope image of a partially dissolved Emiliania huxleyi coccosphere

Ocean acidification poses a potential threat to all marine organisms which produce calcareous skeletons.

Burning of fossil fuels and deforestation is releasing immense volumes of carbon dioxide into the atmosphere, and around 25% is then dissolved into the sea. This is shifting the chemistry of sea water, making it slightly more acidic and making calcification more difficult. [NHM]

Sea urchins from Antarctica show adaptation to ocean acidification

A study of sea urchins from the Antarctic Peninsula has revealed an ability to adapt to changing conditions such as rising sea temperature and acidification. Writing in the Journal of Animal Ecology the authors set out to answer important and fundamental questions on how life in the ocean will respond to projected changes in the coming decades.

Despite evidence of increasing acidification of the world’s oceans, questions remain over whether marine species will be able to adapt to these changing conditions. This latest study, led by scientists from the British Antarctic Survey and Bangor University, is one of the longest ever conducted.

A total of 288 sea urchins were collected by divers from Ryder Bay off the Antarctic Peninsula and transported to the British Antarctic Survey in Cambridge, UK. There they were placed in aquarium tanks and monitored over a two year period. The alkaline content of the seawater they were kept in was lowered by between 0.3 and 0.5 pH units and the temperature was raised by +2°C. The conditions were chosen because they align with end of century (2100) predictions for changes in ocean conditions.

All the animals survived, but took between six to eight months to stabilise their physiology after the change (acclimate to the new conditions). There was no significant change in the size or mass of the urchins during the two year period showing the changed conditions did not affect growth rates in the adults.

The researchers also set out to discover what effect changes in sea conditions would have on breeding and survivability rates for new born urchins. It takes a long time for this species to develop sexual organs so sperm and eggs were fertilised artificially at six and 17 months. At the six month period, the number of larvae that spawned successfully was significantly lower than when the animals were spawned at 17 months emphasising the need for long-term observations.

At the end of the two year period, whilst the animals under the medium pH conditions produced eggs similar in size to the controls in normal seawater, the animals under lowest pH conditions (-0.5) were producing larger eggs. This may be due to higher investment of energy per egg as a way to increase the ability of generations to replace each other and, the researchers suggest, warrants further investigation.

Read more here.

(via Marine Conservation Institute)

Image credit: Chris Weaver

NEW RESEARCH SUGGESTS CARIBBEAN GORGONIAN CORALS ARE RESISTANT TO OCEAN ACIDIFICATION

The first study to analyze the effects of specific climate scenarios on shallow-water soft corals called gorgonians found that these species are able to calcify and grow even under elevated concentrations of carbon dioxide.

A team of researchers tested the effects of elevated CO2 concentrations on the growth and calcification rates of Eunicea fusca, a gorgonian soft coral whose range extends from the Bahamas to the Gulf of Mexico. Gorgonian corals provide essential habitat spaces for reef-dwelling marine organisms. They also belong to a group of corals whose skeletons are formed by high-magnesium calcite (as opposed to aragonite) and which are particularly susceptible to the impacts of ocean acidification – one of the major consequences of global climate change.  

For this study, researchers collected E. fusca specimens from the Florida Keys and brought them to the UM Rosenstiel School’s Coral Reefs and Climate Change Laboratory. For four weeks, the specimens were exposed to different levels of CO2 concentrations. While the calcification and growth rates declined, they did not stop under any of the study’s CO2 levels (which ranged from 285 parts per million to 2,568 parts per million, or a pH range of 8.1 to 7.1), and rates declined only moderately at the mid-elevated CO2 levels.

Chris Langdon, the Director of the Coral Reefs and Climate Change Laboratory and professor at UM Rosenstiel, said that the results suggest that the gorgonian corals may be more resistant to ocean acidification than other reef-dwelling coral species, and that the findings will allow researchers to predict the composition of coral reef communities in the future. As pH levels in the ocean are predicted to have declined from their preindustrial levels by 0.14 to 0.43 units by the year 2100, insight into how marine organisms respond to acidification is becoming increasingly critical.