There was recently a post about data collected in 2011 in the fish near Fukushima. It found that
the fish had absorbed a large quantity of radioactive cesium shortly after the onset nuclear disaster.
Their studies have indicated an enormous amount of radioactive strontium, up to 900 terabecquerels (a terabecquerel is equal to 1 trillion becquerels) was released from the crippled nuclear power plant during the first 90 days, raising concentration levels of strontium 89 and strontium 90 up by up to two orders of magnitude (a hundredfold). Since June of 2011, when the researchers stopped sampling there have been further large discharges of strontium from Fukushima Daiichi that have not been measured with precision.
What is most worrisome about this post is that they have stopped monitoring. If they do not collect data, then they have nothing to hide. Biological tissues regard cesium to be like potassium, and strontium to be like calcium. Potassium and calcium concentrations are dilute in seawater. Biological tissues will concentrate these elements, and they will also concentrate radioactive cesium and strontium. The strontium will be deposited in bone, where it can radiate the bone marrow.
The most important news is that this story is not being updated.