Title: Scientists say contamination of ocean fish minimal so far
Source: Japan Times Online
Author: IZUHO AOKI
Date: Feb. 4, 2012
The massive radioactive fallout from the Fukushima No. 1 nuclear plant has sparked fear in seafood lovers and commercial fishermen both at home and abroad, and some worry the contamination could pass through and even become more concentrated in the ocean food chain.
[...] experts stress that close monitoring of bottom fish off Fukushima should continue because there’s no telling when contamination levels will peak. [...]
Takashi Ishimaru, professor of ocean science at Tokyo University of Marine Science and Technology
- Contaminated plankton and waste from fish naturally sink to the seabed and are then eaten by miniscule benthos organisms, which bottom fish feed on
- As a result, radioactive materials are passed up the food chain.
- “Radioactive materials circulate at the bottom of the ocean. . . . It won’t be reduced easily”
- Researchers have yet to obtain data on how contamination from the Fukushima No. 1 plant has spread along the sea floor, so consumers should keep a watchful eye on bottom fish
- “There could be hot spots under the sea”
- “If hot spots exist on the ocean floor, contamination levels of fish that inhabit such areas may spike”
Satoshi Katayama, professor of fisheries biology and ecology at Tohoku University
- “(Contamination) levels of freshwater fish and seabed fish such as flounder haven’t declined”
- “It’s hard to say the contamination peak among such fish has passed”
[...] beach seine fishing off northern Ibaraki Prefecture was halted late last month.
Meanwhile, samples of freshwater fish caught in Fukushima and Maebashi, Gunma Prefecture, have revealed high levels of contamination exceeding the government limit. Tests conducted between April 19 and Jan. 10 in Gunma on 34 freshwater fish showed that 11 caught in Lake Onuma exceeded the maximum level.
In Tochigi Prefecture, meanwhile, “ayu” (sweet fish) caught in May in the Kinugawa River near the city of Utsunomiya and the Nakagawa River near the town of Motegi contained radioactive cesium above 400 becquerels per kilogram — less than the current provisional limit but four times higher than the new limit the government will introduce in April.
Read the report here
Published: February 4th, 2012 at 8:48 am ET