Along the rocky shores of the San Francisco Bay, common murres—seabirds that have hunted these cold Pacific waters for generations—are starving, and marine biologists are watching with growing dread. The collapse of forage fish populations like anchovies and sardines has unraveled a food web that sustains not just the murres, but an entire coastal ecosystem. What unfolds in the coming months may reveal whether this is a temporary disruption or the beginning of a deeper, more permanent unraveling of the Bay's marine life.