California's coastal habitats face existential threat from rising seas

Climate change is transforming the state's coast but with habitats hemmed in by cliffs, condos and farms, pre-emptive action is needed to preserve biodiversity

The sea otters of Elkhorn Slough float by on their backs, greeting the occasional kayaker with unwanted socializing that can tip a boat. Chubby harbor seals lounge on large rocks and a great blue heron stands tall among hundreds of birds on a sliver of land.

This Monterey Bay estuary south of San Francisco hosts about 20,000 migratory shorebirds a year and is a nursery habitat for fish and shellfish. It's notable for having bolstered the waning population of the curious southern sea otters, which now exceed 100 and are webcast live daily.