The last few weeks have seen another alarming uptick in the number of dead, emaciated seabirds found washed  up on the shores in the Bering Sea.

The animal die-offs offer the world a stark example of the perils of rising ocean temperatures, which already are upending parts of the Bering Sea ecosystem.

From late June to early August, thousands of short-tailed shearwaters were reported dead and washing up on beaches in the Bristol Bay region, or observed weak and attempting to feed from salmon gillnets in inland waters,

Mass die-offs and breeding failures, now ongoing for years, have marine biologists worried that this is a new normal caused by climate change.

Carcasses examined so far have shown no indication of disease, and tests are pending for harmful algal toxins. Seabirds have been found emaciated and starved, and changed ocean conditions may have affected prey.

In the fall of 2014, West Coast residents witnessed a strange, unprecedented ecological event. Tens of thousands of small seabird carcasses washed ashore on beaches from California to British Columbia, in what would become one of the largest bird die-offs ever recorded.

A network of more than