Scientists: California fish harmed by Fukushima radiation? Thyroids are sensitive to iodine-131 — Radioactive marterial probably accumulated in opaleye, halfmoon and senorita
March 31st, 2012
Title: Radioactive Iodine from Fukushima Found in California Kelp
Source: Scientific American
Author: Marla Cone
Date: March 30, 2012
[...] Scientists from California State University, Long Beach tested giant kelp collected in the ocean off Orange County and other locations after the March, 2011 accident, and detected radioactive iodine, which was released from the damaged nuclear reactor.
The largest concentration was about 250-fold higher than levels found in kelp before the accident.
“Basically we saw it in all the California kelp blades we sampled,” said Steven Manley, a Cal State Long Beach biology professor who specializes in kelp. [...]
Some radioactive material probably accumulated in fish that eat the kelp – opaleye, halfmoon and senorita.
“If they were feeding on it, they definitely got dosed. We just don’t know if it was harmful. It’s probably not good for them. But no one knows,” Manley said. “In the marine environment it was significant, but probably not harmful at the levels we detected it, except it may have affected certain fish’s thyroid systems, the ones that fed on the kelp.”
There is no published research on what iodine 131 might do to fish at the levels found in the kelp.
“That is a good question and one we don’t really know the answer to as yet,” said Christopher Lowe, a biology professor and director of Cal State Long Beach’s Sharklab, which studies sharks and game fish. Lowe was co-author of the kelp study.
“Without actually measuring this, my guess is that the effects on fish thyroids from this limited exposure are probably negligible. However, that may not be the case for herbivorous fish species exposed closer to the release site” in Japan, Lowe said.
One toxicologist who works with fish said fish thyroids are sensitive to radioactive iodine but there is no data on its effects. High levels might cause thyroid tumors in the exposed fish or alter their cells’ genetic material.