FUKUSHIMA--The chirping of birds filled the air on the riverbed where the Abukumagawa river runs through the city of Fukushima just after 4 a.m. on May 24.
FUKUSHIMA--The chirping of birds filled the air on the riverbed where the Abukumagawa river runs through the city of Fukushima just after 4 a.m. on May 24.
The river runs south to north through Fukushima Prefecture, and it has provided a studying ground for Noboru Nakamura, a researcher at the Yamashina Institute for Ornithology.
Nakamura has visited the riverbed 20 times since the Great East Japan Earthquake struck on March 11, 2011. He is looking into whether the earthquake or the accident at the Fukushima No. 1 nuclear power plant caused abnormal changes among wild birds.
He has also made trips to the city of Minami-Soma and the village of Iitate in the prefecture.
Nakamura lays a mist net in the reed bed and analyzes the birds he catches every 30 minutes. He records data such as species, gender, wingspan and physical condition, then tags the birds’ legs and releases them. This “bird banding survey” is conducted to learn about birds’ ecologies, migration routes and so on.
The survey starts at sunrise and lasts for six hours. But the birds do not get trapped in the net so easily. On May 24, the “results” consisted of 18 birds, including great reed warblers, bull-headed shrikes and common kingfishers. Other than a great reed warbler with a parasitic disease in the leg, there was nothing particularly odd about the birds.
“In Iitate, I caught a Japanese bush warbler in the net yesterday,” he said. “It had feathers missing from the back of its head, and its skin was dark on that part. I found the same thing last year and the year before in Minami-Soma. I don’t know the reason. I need to study this more. Maybe I’ll catch a Japanese bush warbler today.”
On that day, Nakamura’s wish did not come true.
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The Yamashina Institute for Ornithology’s first verified abnormal change after the magnitude-9.0 earthquake came along a body of water in Niigata Prefecture.
On Oct. 24, 2011, a common reed bunting, a small migratory bird, was found with uneven tail feathers that had a moth-eaten appearance.
The institute started emergency surveys at 17 locations in 14 prefectures from the northeastern Tohoku region to the southern Kyushu region.
“Bird banding surveys of the common reed bunting began in 1961, and nearly 480,000 of the birds have been examined,” said Kiyoaki Ozaki, deputy director-general of the institute. “The tail feathers on the chicks and the adults have different shapes, so we monitor them closely. But this sort of abnormality hasn’t been reported before. I’ve seen thousands of the birds, but it was the first time for me to see tail feathers like these.”
The most perplexing thing was the overly long feathers. The common reed bunting’s body is around 15 centimeters long. Its feathers very reliably grow to a certain length. Birds that are not yet fully grown may have shorter feathers, but Ozaki could not imagine a reason for them to be longer.
By March 2012, the same abnormality was identified at all research sites across Japan, such as Tochigi, Ibaraki, Tokyo, Shizuoka, Shimane, Kagawa and Fukuoka. The proportion of birds with the abnormality was 13.8 percent.
In at least one place, the ratio exceeded 25 percent. Birds born in 2011 account for 97.3 percent of the specimens with the abnormality.
When feathers begin to grow, they are wrapped in a sheath-like structure. Researchers have found feathers that already appear moth-eaten when they split open the sheath. Some birds even grew back feathers with the same deformity after the researchers plucked out older, misshapen feathers.
“There is something unusual occurring inside the birds’ bodies, perhaps with their genes or hormone secretion,” Ozaki said. “That is a possibility, I think.”
The cause is unknown. However, it is “in the realm of possibility” that it could be the effect of radioactive substances.
One thing is certain: The common reed bunting breeds in places like Aomori Prefecture, Hokkaido and Russia’s Kamchatka Peninsula, then migrates to the Kanto region and farther south to pass the winter. All the birds use the Japanese archipelago and pass through or stop in the Tohoku region during their migration. The strange feathers add a new topic of study to the surveys that have been continuing for more than half a century.
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Eighteen years ago, “endocrine disruptors,” or so-called environmental hormones, attracted global interest. In their book “Our Stolen Future,” American zoologist Theo Colborn and her colleagues reported abnormal changes, such as falling sperm counts in men and male fish switching genders. They pointed to the effects of minuscule quantities of chemical substances that had not been seen as a problem until then.
At the time, I also looked into this issue as a reporter. When I think back, the scientific community confronted these abnormal changes in a fairly sincere manner. The Environment Agency, predecessor of the Environment Ministry, conducted a study that ran for seven years and identified a number of substances that exert an effect on the “medaka” killifish and the “ibonishi” sea snail.
The ministry’s survey and research program are continuing.
“The goal is to investigate a suspect substance, even if we don’t know anything about its effects, and decide whether to restrict it,” a ministry official said. “There is still great interest in environmental hormones in the United States and Europe. When a substance is actually found to be harmful, Japan cannot be the only one who ‘didn’t know.’”
What about in the case of a nuclear accident?
Right now, we are living among radioactive substances released from the Fukushima No. 1 nuclear power plant. When considering the effects on our health, the only earlier examples we can refer to are the atomic bombings of Hiroshima and Nagasaki and the Soviet Union’s nuclear disaster at Chernobyl.
The only confirmed effect on health from the Chernobyl accident was thyroid cancer in children. People exposed to radiation have claimed it caused conditions such as leukemia, cataracts, visceral diseases, lowered immunity, fatigue and nosebleeds, but there was thought to be “no proof” that these were caused by the Chernobyl accident.
It is now up to us to investigate the abnormal changes that have been put off since Chernobyl. A nuclear accident is a disaster caused by science. It is also science’s role not to overlook abnormalities that come after an accident and to try and solve these mysteries.