Posted by Richard Conniff on November 23, 2016
(Photo: Yusuke Kawasaki/Flickr).
by Richard Conniff/Scientific American
Levels of highly toxic mercury contamination in Atlantic bluefin tuna are rapidly declining, according to a new study. That trend does not affect recommended limits on consumption of canned tuna, which comes mainly from other tuna species. Nor does it reflect trends in other ocean basins. But it does represent a major break in the long-standing, scary connection between tuna and mercury, a source of public concern since 1970, when a chemistry professor in New York City found excess levels of mercury in a can of tuna and spurred a nationwide recall. Tuna consumption continues to be the source of about 40 percent of the mercury contamination in the American diet. And mercury exposure from all sources remains an important issue, because it causes cognitive impairment in an estimated 300,000 to 600,000 babies born in this country each year.
The new study, published online on November 10 by Environmental Science & Technology, links the decline directly to reduced mercury emissions in North America. Most of that reduction has occurred because of the marketplace shift by power plants and industry away from coal, the major source of mercury emissions. Pollution control requirements imposed by the federal government have also cut mercury emissions.
Progress on both counts could, however, reverse, with President-elect Donald Trump promising
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Posted in Environmental Issues, Food & Drink | Tagged: bluefin, coal, Donald Trump, mercury, tuna | 4 Comments »
Posted by Richard Conniff on March 21, 2015
(Photo: Richard Conniff)
My latest for Takepart:
A few years ago, I was reporting a story about South Africa’s war on rhinos. I suppose you could call it “Vietnam’s war” or “Asia’s war,” since that’s where most of the rhino horn ends up, to supply a bogus medicinal trade. But let’s face it: South Africa’s own political and financial elite tolerate the poaching of more than 1,000 rhinos in the nation every year, probably because they profit from it.
In any case, the obvious place to start my reporting was the birthplace of rhino conservation: Hluhluwe-iMfolozi Park, in the coastal state of Kwazulu-Natal. This is where an earlier generation of South Africans saved the white rhino from certain extinction, carefully breeding the species back from just 20 animals in the world at the end of the 19th century to a population of 20,000 today.
In 1895, they also designated Hluhluwe-iMfolozi (pronounced “shluh-shloo-ee”) Africa’s first nature preserve.
This should be a great national heritage, and also a source of cultural pride: The broad river valleys and rolling highlands of Hluhluwe-iMfolozi were once the favorite hunting ground of Shaka, the storied Zulu warrior king. The park is home not just to white rhinos but also to critically endangered black rhinos, as well as elephants, lions, leopards, buffalo, and 340 species of birds.
But now Ibutho Coal, a little-known mining company Read the rest of this entry »
Posted in Environmental Issues | Tagged: coal, rhinos, South Africa | Leave a Comment »
Posted by Richard Conniff on October 31, 2014
(Photo: Mario Tama/Getty Images)
When most people think about a biological hotspot, a motherlode of species, the Amazon may come to mind, along with certain regions in West Africa and Southeast Asia. Hardly anybody thinks about the Appalachians. But more species of salamanders and freshwater mussels live in the streams and forests of this region, stretching from upstate New York to northern Alabama, than anywhere else in the world. Those temperate, deciduous forests are more diverse than anywhere else in the world, too, apart from those in central China.
Unfortunately, seams of coal also run through the Appalachian Mountains, often buried deep within the range. To extract it, coal companies have been literally blowing the tops off of these mountains in a practice called mountaintop removal coal mining. Not only does this method change the landscape and leave swaths of barren rock in place of forested mountainsides, but the mining companies also take the millions of tons of dynamited rock and dump them in the valleys next to the decapitated mountains. These valleys usually have streams in them, and those streams are where the salamanders, mussels, and other freshwater species of the region live. As you might imagine, these animals don’t love having chunks of mountain dumped on their habitat.
A new study confirms that salamanders, in particular, fare poorly in these streams. Researchers from the University of Kentucky visited sites where mining companies had dumped the so-called “overburden” (or “spoil”) and looked for salamanders just downstream of the dumped mountain debris, comparing the abundance of five salamander species in those streams with nearby streams that hadn’t been disrupted.
Overburdened streams averaged about half as many species of salamander, and far fewer individual salamanders, as the undisturbed streams. Across 11 streams with mountain rubble, researchers found just 97 salamanders, compared with 807 salamanders in a dozen control streams.
How do mining companies get away with it?
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Posted in Environmental Issues | Tagged: coal, salamanders, West Virginia, wildlife | 4 Comments »