Discovered: Nuclear disaster lingers in Japanese waters; the hole in the Antarctic ozone hasn't been this small since the '90s; the problem with algae-derived biofuels; the amazing shrinking ancient hippo.
Fukushima continues to ripple through Japanese fish population. Well over a year and a half after the Tohoku earthquake, and the resulting Dai-ichi power disaster, fish caught off Japan's east coast still have radioactive contamination, officials have found. Four out of 10 fish caught in the affected regions are unfit for human consumption, according to Japanese seafood regulation. Woods Hole Oceanographic Institution marine chemist Ken Buesseler looked over the data, and published a paper in Science this week in which he explains, "It all points to this issue being long-term and one that will need monitoring for decades into the future." Most fish caught in northeastern Japan should be safe to eat, Buesseler insists, especially considering that Japanese authorities reduced the regulatory threshold from 500 becquerels of caesium per kilogram of wet weight to 100 Bq/kg. [BBC News]
Ozone hole above Antarctica shrinks to 20-year low. The gap in the ozone layer above the Antarctic has been smaller this year compared with trends observed over previous decades. It reached a maximum area of 8.2 million square miles in late September. That's undoubtedly huge—roughly the size of the North American continent—but is noticeably smaller than records set in recent years (compare this year's number with 2000's, 11.5 million square miles). So what's causing the shrinkage? Warmer than average temperatures in the South Pole, says NOOA's Earth System Research Laboratory scientist Jim Butler: "It happened to be a bit warmer this year high in the atmosphere above Antarctica, and that meant we didn't see quite as much ozone depletion as we saw last year, when it was colder." This doesn't suggest, however, that CFC pollution has abated enough to repair the ozone, or that climate change is slowing down. [Christian Science Monitor]