A long-running effort by native tribes and environmentalists to establish the first new national marine sanctuary along California’s coastline in 32 years — the aquatic version of a new national park, where offshore oil drilling would be prohibited forever — reached a key milestone Friday. The Biden administration published the final environmental impact statement for the Chumash Heritage National Marine Sanctuary, selecting boundaries that will stretch along 116 miles of coast in San Luis Obispo and Santa Barbara counties. The area, which includes popular spots such as Pismo Beach and the Gaviota Coast, is home to humpback whales, sea otters, leatherback sea turtles, kelp forests, rocky reefs and more than 200 shipwrecks. Under the proposal, the sanctuary will cover 4,543 square miles — an area nearly four times the size of Yosemite National Park — and extend 60 miles offshore.