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Climate change may bring acidic oceans full of jellyfish
One often-neglected result of climate change is ocean acidification. If this process continues, we may start to see fewer fish and more jellyfish.
- Since the beginning of the industrial era, humanity has been pumping out unprecedented levels of CO2 into the atmosphere.
- A significant portion of this CO2 is sucked back into the ocean, where it reacts with water to produce carbonic acid.
- Most species fair poorly in the newly acidic ocean. Jellyfish, however, seem to resist ocean acidification more than others.
Human beings don't do well when they try to understand things past a certain scale. When you consider the 7.5 billion people on the planet, you don't think of them in the same way as, say, the people who you meet walking your dog or your extended family. People can't conceive of how small the Earth is in comparison with the Sun, and people can't conceive of how broad and ubiquitous climate change really is — which is why some folks scoff at the idea when the Northeast US experiences record snowfall.
Most of us limit our understanding of climate change to the impact that CO2 has on our atmosphere and the resulting warming of the planet. But climate change is a multifaceted phenomenon. As we change our planet's chemistry, all environments experience a subsequent change, not just through the air we breathe but also in the oceans. The oceans of the future won't just be bigger from melting sea ice; they will become acidic seas where the jellyfish reign supreme.
Why the ocean you know and love won’t exist in 50 years
How CO2 turns oceans acidic
CO2 released into the atmosphere traps heat, driving the bulk of climate change's obvious effects. But not all of that CO2 stays in the atmosphere. Since the beginning of the industrial age, the world's oceans have absorbed 525 billion tons of CO2. Today, oceans suck up about 22 million tons per day, roughly a quarter of all the man-made CO2 released into the atmosphere.
In a way, this is helpful. If more CO2 was retained in the atmosphere, the faster the planet would heat up from the greenhouse gas effect. There's no such thing as a free lunch, however. As CO2 mixes with the oceans' H2O, the two molecules combine to form carbonic acid (H2CO3), lowering the oceans' pH and increasing its acidity. Under normal circumstances, natural processes from the dissolved minerals deposited into the oceans by rivers help to keep the oceans' pH levels in balance, but the rate at which oceans are absorbing our CO2 means this process has not been sufficient.
Life under ocean acidification
PHILIPPE LOPEZ/AFP/Getty Images
Nearly all forms of life are extremely sensitive to pH levels. You can imagine how difficult it would be for humanity if all of our air was slightly acidic — such is the case in the oceans. But, like any environmental change, there are losers and winners.
The most obvious loser in this new environment are species that build shells, like oysters, clams, and corals. Any disruption to a food chain puts an ecosystem in danger, but the increased difficulty that corals face when building their shells is particularly worrisome. Corals are a foundation species, meaning that they create and maintain a habitat for other species. Without them, an estimated 4,000 species will be at risk.
While many species of shell-building animals and fish are negatively impacted by ocean acidification, jellyfish don't seem to struggle much at all. One of the ways scientists discovered this was by looking at places in the ocean where CO2 levels are naturally higher, such as nearby volcanic seeps in the Mediterranean. In these locations, jellyfish and other "nuisance" species like dangerous algae exist in much higher numbers than elsewhere. Additional research, too, has demonstrated that as pH levels drop in the ocean, jellyfish numbers rise.
It's unclear how jellyfish will fare as the oceans become even more acidic in the future. So far, it seems they are resistant to acidification, but not immune to it. Some researchers believe that the selectivity of this damage — that ocean acidification seems to affect other species more — is what's leading to the jellyfish's rise. As their competitors and prey becomes less fit, jellyfish capitalize by ramping up their consumption.
As an example, one study looked at how well copepods and jellyfish fared in tanks of normal ocean water and tanks of acidified ocean water. Copepods are small, abundant crustaceans that are critical to ocean ecology, serving as a food source for nearly every species. When box jellyfish were added to the copepod tanks that contained normal ocean water, the jellyfish consumed 37% of the copepods. When added to the acidified tanks, jellyfish ate 83% of the copepods. However, it's not clear whether this occurred because the copepods had been weakened by the acidification, whether the jellyfish became hungrier under the strain of acidification, or some combination of the two.Jellyfish numbers appear to be on the rise, and it looks like ocean acidification is to blame. Unless we learn to curb our CO2 outputs, it may be that our future oceans may become more gelatinous than we'd like.
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Some mysteries take generations to unfold.
- In 1959, a group of nine Russian hikers was killed in an overnight incident in the Ural Mountains.
- Conspiracies about their deaths have flourished ever since, including alien invasion, an irate Yeti, and angry tribesmen.
- Researchers have finally confirmed that their deaths were due to a slab avalanche caused by intense winds.
a: Last picture of the Dyatlov group taken before sunset, while making a cut in the slope to install the tent. b: Broken tent covered with snow as it was found during the search 26 days after the event.
Photographs courtesy of the Dyatlov Memorial Foundation.<p>Finally, a <a href="https://www.nature.com/articles/s43247-020-00081-8" target="_blank">new study</a>, published in the Nature journal Communications Earth & Environment, has put the case to rest: it was a slab avalanche.</p><p>This theory isn't exactly new either. Researchers have long been skeptical about the avalanche notion, however, due to the grade of the hill. Slab avalanches don't need a steep slope to get started. Crown or flank fractures can quickly release as little as a few centimeters of earth (or snow) sliding down a hill (or mountain). </p><p>As researchers Johan Gaume (Switzerland's WSL Institute for Snow and Avalanche Research SLF) and Alexander Puzrin (Switzerland's Institute for Geotechnical Engineering) write, it was "a combination of irregular topography, a cut made in the slope to install the tent and the subsequent deposition of snow induced by strong katabatic winds contributed after a suitable time to the slab release, which caused severe non-fatal injuries, in agreement with the autopsy results."</p><p>Conspiracy theories abound when evidence is lacking. Twenty-six days after the incident, a team showed up to investigate. They didn't find any obvious sounds of an avalanche; the slope angle was below 30 degrees, ruling out (to them) the possibility of a landslide. Plus, the head injuries suffered were not typical of avalanche victims. Inject doubt and crazy theories will flourish.</p>
Configuration of the Dyatlov tent installed on a flat surface after making a cut in the slope below a small shoulder. Snow deposition above the tent is due to wind transport of snow (with deposition flux Q).
Photo courtesy of Communications Earth & Environment.<p>Add to this Russian leadership's longstanding battle with (or against) the truth. In 2015 the Investigative Committee of the Russian Federation decided to reopen this case. Four years later the agency concluded it was indeed a snow avalanche—an assertion immediately challenged within the Russian Federation. The oppositional agency eventually agreed as well. The problem was neither really provided conclusive scientific evidence.</p><p>Gaume and Puzrin went to work. They provided four critical factors that confirmed the avalanche: </p><ul><li>The location of the tent under a shoulder in a locally steeper slope to protect them from the wind </li><li>A buried weak snow layer parallel to the locally steeper terrain, which resulted in an upward-thinning snow slab</li><li>The cut in the snow slab made by the group to install the tent </li><li>Strong katabatic winds that led to progressive snow accumulation due to the local topography (shoulder above the tent) causing a delayed failure</li></ul><p>Case closed? It appears so, though don't expect conspiracy theories to abate. Good research takes time—sometimes generations. We're constantly learning about our environment and then applying those lessons to the past. While we can't expect every skeptic to accept the findings, from the looks of this study, a 62-year-old case is now closed.</p><p> --</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a> and <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a>. His most recent book is</em> "<em><a href="https://www.amazon.com/gp/product/B08KRVMP2M?pf_rd_r=MDJW43337675SZ0X00FH&pf_rd_p=edaba0ee-c2fe-4124-9f5d-b31d6b1bfbee" target="_blank" rel="noopener noreferrer">Hero's Dose: The Case For Psychedelics in Ritual and Therapy</a>."</em></p>
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Research reveals a new evolutionary feature that separates humans from other primates.
- Researchers find a new feature of human evolution.
- Humans have evolved to use less water per day than other primates.
- The nose is one of the factors that allows humans to be water efficient.
A model of water turnover for humans and chimpanzees who have similar fat free mass and body water pools.
Credit: Current Biology
Being skeptical isn't just about being contrarian. It's about asking the right questions of ourselves and others to gain understanding.