Agreed that ANY radioactive waste pouring into the ocean.  BUT, I thought the Murre die-off was solidly linked to malnutrition which is currently thought to have been caused by abnormally warm waters pushing the Murre food deeper and further offshore than normal.  Given the El Nino/Blob we just had this makes sense.  
It is not hard to measure radioactivity and there is no conspiracy of scientists trying to hide unusual levels of radioactivity in the oceans (why on earth would they?).  So while I agree radioactive pollution is an issue, I don't believe it has any relevance to the Murre die-off.