As radioisotopes pour into the sea from the crippled Fukushima Daiichi nuclear plant, one reassuring message has been heard over and over again: the Pacific Ocean is a big place.
That the isotopes will be vastly diluted is not in question. Nevertheless, scientists are calling for a marine survey to begin as soon as possible to assess any damage to ecosystems in the area around Fukushima. Although the contamination is unlikely to cause immediate harm to marine organisms, long-lived isotopes are expected to accumulate in the food chain and may cause problems such as increased mortality in fish and marine-mammal populations.
"Just because you can measure it, doesn't mean it's dangerous," says Ken Buesseler, a marine geochemist at the Woods Hole Oceanographic Institution in Massachusetts. "Even so, this is the biggest man-made release ever of radioactive material into the oceans. We haven't yet seen enough data to assess what's going on, so anything that can be done in terms of further monitoring would be very welcome."
http://www.nature.com/news/2011/110412/full/472145a.html