This is the time of year when birds come out and really spread their wings, but since a disastrous day just before spring’s arrival four years ago, Japan’s Fukushima province has not been friendly to the feathered. And as several recent papers from University of South Carolina biologist Tim Mousseau and colleagues show, the avian situation there is just getting worse.
This is the time of year when birds come out and really spread their wings, but since a disastrous day just before spring’s arrival four years ago, Japan’s Fukushima province has not been friendly to the feathered. And as several recent papers from University of South Carolina biologist Tim Mousseau and colleagues show, the avian situation there is just getting worse.
Since a few months after the March 11, 2011, earthquake, tsunami and subsequent nuclear catastrophe at Japan’s Fukushima-Daiichi nuclear power plant, Mousseau and several co-workers have undertaken a series of bird censuses in contaminated areas. They recently published a paper in the Journal of Ornithology showing results from the first three years of the effort for 57 bird species.
Many populations were found to have diminished in number as a result of the accident, with several species suffering dramatic declines. One hard-hit species was the barn swallow, Hirundo rustica, which suffered large population losses in a dose-dependent manner according to individually measured levels of radiation exposure.
The researchers looked more closely with the barn swallow, trying to isolate the mechanism causing the population decrease with their first two years of data. But as Mousseau, his postdoctoral associate Andrea Bonisoli-Alquati and colleagues reported in a separate recently published study in the journal Scientific Reports, their tests of peripheral erythrocytes in individual barn swallow nestlings failed to show genetic damage as a result of direct-dose radiation effects. Nevertheless, the more detailed study showed a dose-response decrease in both numbers and fraction of juveniles.
“We were working with a relatively small range of background exposures in this study because we weren’t able to get into the ‘hottest’ areas that first summer after the disaster, and we were only able to get to some ‘medium-hot’ areas the following summer,” Mousseau says. “So we had relatively little statistical power to detect those kinds of relationships, especially when you combine that with the fact that there are so few barn swallows left. We know that there were hundreds in a given area before the disaster, and just a couple of years later we’re only able to find a few dozen left. The declines have been really dramatic.”
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Barn swallow image via Shutterstock.
