The return of sea otters and their voracious appetites has helped rescue a section of California marshland, a new study shows.

Sea otters eat constantly and one of their favorite snacks is the striped shore crab. These crabs dig burrows and also nibble away roots of the marsh grass pickleweed that holds dirt in place.

Left unchecked, the crabs turn the marsh banks “into Swiss cheese,” which can collapse when big waves or storms hit, said Brent Hughes, a Sonoma State University marine ecologist and co-author of the new study published Wednesday in the journal Nature.

Researchers found that the return of the crab-eating sea otters to a tidal estuary near Monterey, California, helped curb erosion.