These «unusual mortality events» continued through at least summer 2014. (scientificamerican.com)
This right whale — the latest casualty in an ongoing unusual mortality event in which 18 animals have died — was found floating, dead, off the coast of Virginia in January. (washingtonpost.com)
Review of marine mammal unusual mortality events in the United States: 1992 - 2005. (marinemammalcenter.org)