Saturday January 19, 2019

Here’s Why Man-made Pesticides Affect Marine Animals More

The study calls for monitoring our waterways to learn more about the impact of pesticides and agricultural run-off on marine mammals.

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Marine animals are more vulnerable to man-made pesticides. Flickr

Marine mammals such as dolphins, manatees, seals and whales, which evolved to make water their primary habitat, lost the ability to make a gene that defends humans and other land-dwelling mammals from the neurotoxic effects of a popular human-made pesticide, a new study has revealed.

The researchers found that the marine mammals lost the gene Paraoxonase 1 (PON1) that effectively defends humans and other terrestrial mammals from organophosphates — a group of man-made insecticides.

PON1 potentially reduces cellular damage caused by unstable oxygen atoms and also protects us from organophosphates that kills by disrupting neurological systems.

Whales and dolphins lost the gene PON1 soon after they split from their common ancestor with hippopotamuses 53 million years ago; manatees lost it after their split from their common ancestor with elephants 64 million years ago.

Marine life
Whales and dolphins lost the gene PON1. VOA

But some seals likely lost PON1 function more recently, at most 21 million years ago and possibly in very recent times.

“The big question is, why did they lose function at PON1 in the first place? It’s hard to tell whether it was no longer necessary or whether it was preventing them from adapting to a marine environment,” said lead author Wynn K. Meyer, postdoctoral associate at the University of Pittsburgh in the US.

“We know that ancient marine environments didn’t have organophosphate pesticides, so we think the loss might instead be related to PON1’s role in responding to the extreme oxidative stress generated by long periods of diving and rapid resurfacing,” Meyer added.

For the study, appearing in the journal Science, the team analysed DNA sequences from five species of marine mammals and 53 species of terrestrial mammals and reacted their blood samples with an organophosphate by-product.

 Marine Mammals lost the ability that defends humans and other land-dwelling mammals from the neurotoxic effects of a popular human-made pesticide.
Marine Animals lost the ability that defends humans and other land-dwelling mammals from the neurotoxic effects of a popular human-made pesticide.

The blood did not break down the organophosphate by-product the way it did in land mammals, indicating that unless a different biological mechanism is protecting the marine mammals, they would be susceptible to organophosphate poisoning — a form of poisoning that results from the build-up of chemical signals in the body, especially the brain.

Also Read: European Countries Bans Bee-Killing Pesticides

The study calls for monitoring our waterways to learn more about the impact of pesticides and agricultural run-off on marine mammals.(IANS)

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Temperatures Of The Ocean Rising Faster Than Previously Believed: Scientists

Climate changing emissions continue to rise, and I don’t think enough is being done to tackle the rising temperatures

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A woman photographs the sunrise at Ocean Park, in Old Orchard Beach, Maine, July 12, 2018. VOA

The world’s oceans are rising in temperature faster than previously believed as they absorb most of the world’s growing climate-changing emissions, scientists said Thursday.

Ocean heat – recorded by thousands of floating robots – has been setting records repeatedly over the last decade, with 2018 expected to be the hottest year yet, displacing the 2017 record, according to an analysis by the Chinese Academy of Sciences.

That is driving sea level rise, as oceans warm and expand, and helping fuel more intense hurricanes and other extreme weather, scientists warn.

The warming, measured since 1960, is faster than predicted by scientists in a 2013 Intergovernmental Panel on Climate Change report that looked at ocean warming, according to the study, published this week in the journal Science.

 

Trash, Ocean, temperature
A ship tows The Ocean Cleanup’s first buoyant trash-collecting device toward the Golden Gate Bridge in San Francisco en route to the Pacific Ocean, Sept. 8, 2018. VOA

 

“It’s mainly driven by the accumulation of greenhouse gases such as carbon dioxide in the atmosphere due to human activities,” said Lijing Cheng, a lead author of the study from the Chinese Academy of Sciences.

The increasing rate of ocean warming “is simply a signature of increasing greenhouse gases in the atmosphere,” Cheng said.

Leading climate scientists said in October that the world has about 12 years left to shift the world away from still rising emission toward cleaner renewable energy systems, or risk facing some of the worst impacts of climate change.

Those include worsening water and food shortages, stronger storms, heatwaves and other extreme weather, and rising seas.

For the last 13 years, an ocean observing system called Argo has been used to monitor changes in ocean temperatures, Cheng said, leading to more reliable data that is the basis for the new ocean heat records.

Ocean, Temperature
This photo provided by NOAA Corps shows the deployment of an Argo float to capture ocean temperature data.VOA

The system uses almost 4,000 drifting ocean robots that dive to a depth of 2,000 meters every few days, recording temperature and other indicators as they float back to the surface.

Through the data collected, scientists have documented increases in rainfall intensity and more powerful storms such as hurricanes Harvey in 2017 and Florence in 2018.

Cheng explained that oceans are the energy source for storms, and can fuel more powerful ones as temperatures – a measure of energy – rise.

Storms over the 2050-2100 period are expected, statistically, to be more powerful than storms from the 1950-2000 period, the scientist said.

Cheng said that the oceans, which have so far absorbed over 90 percent of the additional sun’s energy trapped by rising emissions, will see continuing temperature hikes in the future.

Oceans, Temperature
People walk on the beach of Biarritz, southwestern France, along the Atlantic Ocean, Dec. 18, 2015. New research shows the oceans are storing much more heat than previously thought. VOA

Because the ocean has large heat capacity it is characterized as a ˜delayed response” to global warming, which means that the ocean warming could be more serious in the future,” the researcher said.

“For example, even if we meet the target of Paris Agreement (to limit climate change), ocean will continue warming and sea level will continue rise. Their impacts will continue.” If the targets of the Paris deal to hold warming to “well below” 2 degrees Celsius, or preferably 1.5C can be met, however, expected damage by 2100 could be halved, Cheng said.

Also Read: Trash-Collecting Device Breaks Apart In The Pacific Ocean

For now, however, climate changing emissions continue to rise, and I don’t think enough is being done to tackle the rising temperatures,” Cheng said. (VOA)