Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

Burning Less Coal = 19% Less Mercury in the Tuna You Eat

Animals
Burning Less Coal = 19% Less Mercury in the Tuna You Eat

I couldn't, post-election, muster a plausibly big enough piece of good news to warrant a Thanksgiving blog—but then this morning one arrived. In an astonishingly short eight years, as a result of tougher emission rules on power plants and a declining use of coal, concentrations of mercury in Atlantic Bluefin tuna, the sushi sort, dropped by 19 percent.

There are similar findings for bluefish, but tuna are much longer lived, so the results are extremely surprising—concentrations of mercury in even much older tuna fell at the same or faster rate as mercury concentrations in sea water, suggesting that fisheries contamination can be reversed far more quickly than anyone had dreamed.

Bluefin tuna are still not healthy for women of child-bearing age—and most of the tuna which had led more than 10 percent of U.S. women having unhealthy mercury in their blood is not from the Atlantic ocean, which is healing, but from the Pacific, where coal consumption and mercury loading remains unabated.

Mercury contamination is a serious public health issue. In the U.S. alone, hundreds of thousands of newborns are at risk of lower IQ's from the mercury burden they are born with. Concentrations of mercury have been coming down as a result of broad public education and advisories on which fish to avoid. Overall, mercury emissions in the U.S. have declined sharply as a result of U.S. Environmental Protection Agency regulation.

Now the news from the North Atlantic suggests that globally the epidemic of mercury poisoning can be reversed far more rapidly than scientists had imagined. Requiring the clean up of coal power plant emissions in Asia, the globe's largest remaining source of mercury pollution, will begin to allow Pacific ocean fisheries to recover as well. It's important that countries considering the economics of building coal factor in the almost certain necessity to control for mercury—and when they do, they are likely to find that coal power is no longer economically competitive, so that not only will current plants reduce their emissions, but fewer new ones will make any kind of economic sense—which will be wonderful news for the communities where coal is mined and burned, as well as the climate.

More fundamentally, the North Atlantic story goes at the heart of the popular version of climate denialism—which is the initially plausible notion that the world is so large and each human so small, that it's just not likely that anything each of us does can really change the climate—or poison the oceans. And if we have, it's so terrifying that we really don't believe we can do anything about it. Isn't it too late?

What the declining mercury level in Bluefin tuna shows is that we can—and have—had enormous impacts on the natural world, but that we can, and are, reversing those impacts. Nature, if we stop abusing her, can heal herself not in centuries or even decades, but mere years—even the length of the U.S. president's term.

This is a good news story we need to tell everyone.

Sustainable t-shirts by Allbirds are made from a new, low-carbon material that uses a mineral extract from discarded snow crab shells. Jerry Buttles / Allbirds

In the age of consumption, sustainability innovations can help shift cultural habits and protect dwindling natural resources. Improvements in source materials, product durability and end-of-life disposal procedures can create consumer products that are better for the Earth throughout their lifecycles. Three recent advancements hope to make a difference.

Read More Show Less

EcoWatch Daily Newsletter

A net-casting ogre-faced spider. CBG Photography Group, Centre for Biodiversity Genomics / CC BY-SA 3.0

Just in time for Halloween, scientists at Cornell University have published some frightening research, especially if you're an insect!

The ghoulishly named ogre-faced spider can "hear" with its legs and use that ability to catch insects flying behind it, the study published in Current Biology Thursday concluded.

"Spiders are sensitive to airborne sound," Cornell professor emeritus Dr. Charles Walcott, who was not involved with the study, told the Cornell Chronicle. "That's the big message really."

The net-casting, ogre-faced spider (Deinopis spinosa) has a unique hunting strategy, as study coauthor Cornell University postdoctoral researcher Jay Stafstrom explained in a video.

They hunt only at night using a special kind of web: an A-shaped frame made from non-sticky silk that supports a fuzzy rectangle that they hold with their front forelegs and use to trap prey.

They do this in two ways. In a maneuver called a "forward strike," they pounce down on prey moving beneath them on the ground. This is enabled by their large eyes — the biggest of any spider. These eyes give them 2,000 times the night vision that we have, Science explained.

But the spiders can also perform a move called the "backward strike," Stafstrom explained, in which they reach their legs behind them and catch insects flying through the air.

"So here comes a flying bug and somehow the spider gets information on the sound direction and its distance. The spiders time the 200-millisecond leap if the fly is within its capture zone – much like an over-the-shoulder catch. The spider gets its prey. They're accurate," coauthor Ronald Hoy, the D & D Joslovitz Merksamer Professor in the Department of Neurobiology and Behavior in the College of Arts and Sciences, told the Cornell Chronicle.

What the researchers wanted to understand was how the spiders could tell what was moving behind them when they have no ears.

It isn't a question of peripheral vision. In a 2016 study, the same team blindfolded the spiders and sent them out to hunt, Science explained. This prevented the spiders from making their forward strikes, but they were still able to catch prey using the backwards strike. The researchers thought the spiders were "hearing" their prey with the sensors on the tips of their legs. All spiders have these sensors, but scientists had previously thought they were only able to detect vibrations through surfaces, not sounds in the air.

To test how well the ogre-faced spiders could actually hear, the researchers conducted a two-part experiment.

First, they inserted electrodes into removed spider legs and into the brains of intact spiders. They put the spiders and the legs into a vibration-proof booth and played sounds from two meters (approximately 6.5 feet) away. The spiders and the legs responded to sounds from 100 hertz to 10,000 hertz.

Next, they played the five sounds that had triggered the biggest response to 25 spiders in the wild and 51 spiders in the lab. More than half the spiders did the "backward strike" move when they heard sounds that have a lower frequency similar to insect wing beats. When the higher frequency sounds were played, the spiders did not move. This suggests the higher frequencies may mimic the sounds of predators like birds.

University of Cincinnati spider behavioral ecologist George Uetz told Science that the results were a "surprise" that indicated science has much to learn about spiders as a whole. Because all spiders have these receptors on their legs, it is possible that all spiders can hear. This theory was first put forward by Walcott 60 years ago, but was dismissed at the time, according to the Cornell Chronicle. But studies of other spiders have turned up further evidence since. A 2016 study found that a kind of jumping spider can pick up sonic vibrations in the air.

"We don't know diddly about spiders," Uetz told Science. "They are much more complex than people ever thought they were."

Learning more provides scientists with an opportunity to study their sensory abilities in order to improve technology like bio-sensors, directional microphones and visual processing algorithms, Stafstrom told CNN.

Hoy agreed.

"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.

Trending

There are many different CBD oil brands in today's market. But, figuring out which brand is the best and which brand has the strongest oil might feel challenging and confusing. Our simple guide to the strongest CBD oils will point you in the right direction.

Read More Show Less
Financial institutions in New York state will now have to consider the climate-related risks of their planning strategies. Ramy Majouji / WikiMedia Commons

By Brett Wilkins

Regulators in New York state announced Thursday that banks and other financial services companies are expected to plan and prepare for risks posed by the climate crisis.

Read More Show Less
The left image shows the OSIRIS-REx collector head hovering over the Sample Return Capsule (SRC) after the Touch-And-Go Sample Acquisition Mechanism arm moved it into the proper position for capture. The right image shows the collector head secured onto the capture ring in the SRC. NASA / Goddard / University of Arizona / Lockheed Martin

A NASA spacecraft has successfully collected a sample from the Bennu asteroid more than 200 million miles away from Earth. The samples were safely stored and will be preserved for scientists to study after the spacecraft drops them over the Utah desert in 2023, according to the Associated Press (AP).

Read More Show Less

Support Ecowatch