how do civilizations collapse?

Try failure to recognize changes in the ecosystem, failure to react, and ineffective reactions...

Off Southern California, zooplankton are down 70 percent, fish larvae 50 percent, and there have been massive die-offs of kelp.

In Puget Sound, the number of seabirds has dropped by nearly half since the 1970s.
At Triangle Island in British Columbia and California's Farallon Islands, scientists saw a third seabird, the Cassin's auklet, show signs of starvation, said Bill Sydeman of the Point Reyes Bird Observatory.

The Farallon auklets started the breeding season late. Only half as many as normal even tried. Then they abandoned the nests.

Researchers recorded low catches of juvenile salmon and rockfish, and there were sightings of emaciated gray whales. Those findings were preceded by the first appearance in Washington waters of thousands of squid normally not found north of San Francisco. And a plankton typically found near San Diego bloomed along Northwest beaches.

In Washington, the state's largest colony of glaucous-winged gulls suffered when the normal fledge count plummeted from 8,000 chicks to 88 last year.

... tick, tick, tick...