NARRAGANSETT — When the U.S. Fish and Wildlife Service and The Nature Conservancy started building up a salt marsh on the Narrow River two years ago to protect it from rising seas, they didn’t really know how the project would turn out.At that time in winter 2016, the two partners had largely completed similar work at Sachuest Marsh in Middletown, but that project was the first of its kind in New England and it was too soon to say whether it had succeeded in keeping [...]