The ocean is still considered as a trash can. Radioactive releases by Japan are increased by a decrease of vigilance. What is occurring in the Pacific Ocean is probably inevitable. However it is not excusable nor should it be viewed as routine as many scientific experts in dispersion and farfetched comparison are currently stating. This type of practice would be impossible in the North East Atlantic. Contracting Parties to the OSPAR Convention follow carefully step by step the slow progression of iodine 131, of cesium 137 and of plutonium released by nuclear installations along the Channel and the North Sea to the Arctic Ocean.
In order to reduce radioactive contamination to marine resources, the OSPAR strategy, to which 15 contracting parties conform, including France and The United Kingdom, aim at obtaining close to zero emissions and losses of radioactive discharges by 2020. Following an event comparable to what is happening in Japan, fishing would progressively be banned in the Channel, in the North Sea and in sub-Arctic and Arctic waters.
Asia has neither this privilege nor this shield. In Asia it is every man for himself and nuclear for all. The Japanese State once again lassos a perfect circle excluding fishing in an area of 20km around the nuclear plant of Fukushima Daiichi. Are migrating fish, dolphins, shellfish and currents also excluded from this zone?
A circular current is susceptible of carrying pollutants and floating waste off the coast of Sendaï. Marine litter can also adsorb chemical and micro radioactive pollutants. Some of this marine litter, such as plastic wrappers, could be eaten by cetaceans. A local current runs along the East coast of Honshu, the principal island of Japan, from the north flowing towards the south to Tokyo. It is an extension of the Oyashio, a cold current flowing from the Arctic. It flows past the Fukushima-Daiichi reactors and spent fuel pools. Slightly north of Tokyo this local current flows out to sea. It interacts with the Kuroshio, “the black stream”, which flows up from the Philippines and reaches Southern Japan around the Ryukyu Islands. The Kuroshio is a warm water current. The convergence of the warm current Kuroshio and the cold current Oyashio, provokes a bloom of plankton, which is the corner stone of marine biodiversity and of the food web with numerous cetacean species at the top. The Kuroshio and the eastern drift of the Oyashio interact at 40° latitude forming the North Pacific current. This current flows towards California, then, in a gyrating pattern turns back south then West to the Philippines and finally Japan while an extension of the North Pacific drift turns towards Alaska. This cycle takes 3 to 4 years.
The climatic and biological role of the Kuroshio is of such importance that in 1970 the Cooperative Study of the Kuroshio (CSK) was launched by China, Indonesia, Japan, South Korea, the Philippines, the former Soviet Union, Thailand, Vietnam, Hong Kong, Singapore and the United States. This international cooperation finished in 1977.
An inventory on accumulation zones of chemical and radioactive pollutants sedimented or transported by surface currents is not precise. However, in the framework of studies on the drifting of marine litter in the Pacific Ocean, two large zones have been discovered, one around the Hawaiian Islands and a second off the coast of Japan. Very little is known about deepwater currents in the North Pacific.
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