CATHLAMET — More than eight decades after their demise, fish traps are getting a fresh look from researchers convinced they offer a more sustainable way to catch Columbia River salmon. These traps are formed by nets attached to pilings that gently guide the fish into a kind of underwater corral. Wild fish protected under the federal Endangered Species Act can be released to resume their upstream journey, while their more abundant hatchery brethren are sent to the processors. “It’s the future,” said Kurt Beardslee, executive director of the Wild Fish Conservancy.