Mass die-off of seabirds from California to BC

The die-off seems confined to one specific species - that is rather odd. Looking forward to hearing the cause.

Parks Canada staff collected 157 dead Cassin’s auklets from a small section of Long Beach nearby. Some were frozen and sent for necropsies to try to understand what is causing the mass die-off.

Others have reported finding hundreds of the birds on beaches in Haida Gwaii, located to the north of Vancouver Island.
— http://www.cbc.ca/news/canada/british-columbia/cassin-auklets-found-washed-up-near-tofino-1.2891409