The California sea otter, once hunted to the edge of extinction, has staged a thrilling comeback in the last century. Now, a team of scientists has discovered that the otters’ success story has led to something just as remarkable: the restoration of their declining coastal marsh habitat. “To me, it’s quite an optimistic message,” says Christine Angelini, a coastal ecologist at the University of Florida and one of the authors of the study published in the journal Nature. It’s a demonstration, she says, “that the conservation of a top predator can really enhance the health and the resilience of a system that’s otherwise under a large portfolio of stress.” … Elkhorn Slough in Monterey Bay, California is the second largest estuary in the US. For decades, it was falling apart. ”They opened up a new harbor in the 1940’s that created this full permanent opening to the ocean,” says Brent Hughes, a marine ecologist at Sonoma State University. “And so all this new tidal energy was eroding away the marshes.”