Radioactivity at Fukushima

Compare these two articles.

The levels of cesium in fish has gone up from 510,000 to 740,000 bequerels per kilogram within the space of two weeks

Record cesium level detected in fish caught near Fukushima nuclear plant

(Kyodo) – Tokyo Electric Power Co. said Friday it detected a record 740,000 becquerels per kilogram of radioactive cesium in a fish caught in waters near the crippled Fukushima Daiichi Nuclear Power Station, equivalent to 7,400 times the state-set limit deemed safe for human consumption.

The greenling measuring 38 cm in length and weighing 564 grams was caught near a water intake of the four reactor units in the power station’s port on Feb. 21 during the utility’s operation to remove fish from the port.

Tepco has installed a net on the sea floor of the port exit in Fukushima Prefecture to make it hard for fish living near the sediments of contaminated soil to go elsewhere.

According to Tepco, the previous record of cesium concentration in fish was 510,000 Bq/kg detected in another greenling captured in the same area. Currently, fishermen are voluntarily suspending operations off the coast of the prefecture except for experimental catches.

http://www.japantimes.co.jp/news/2013/03/16/national/record-cesium-level-detected-in-fish-caught-near-fukushima-nuclear-plant/#.UUeKk1tgZSY

Two weeks earlier.....

Record cesium level found in Fukushima fish

March 2013 (The Asahi Shimbun) – A record concentration of radioactive cesium--5,100 times the government's food safety standard--was detected in a fish caught near the crippled Fukushima No. 1 nuclear plant, the plant’s operator said Feb. 28.

Tokyo Electric Power Co. said the reading of 510,000 becquerels per kilogram in the greenling is the highest ever recorded in the utility’s seafood sampling surveys following the March 2011 disaster at the nuclear plant.

The finding was announced Feb. 28 at a meeting of leaders of the Fukushima Prefectural Federation of Fisheries Cooperative Associations.

The greenling was found caught Feb. 17 in a gill net at the mouth of the plant's port. The net was installed to prevent fish from drifting outside.

A rockfish found caught Feb. 15 in a cage net along a wharf in the port produced a reading of 277,000 becquerels per kilogram, according to TEPCO.

TEPCO told the fisheries federation that it will step up measures to contain radioactive fish.

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201303010040