Stretches of California’s 1,100-mile coastline may soon be put completely off-limits to fishing, a dramatic step some policymakers are contemplating as a way to help decimated fish populations. A 37-acre reserve already exists in the Channel Islands National Park, but officials are considering a proposal that would dramatically expand the no-take zones in the park to include 25,000 acres, or some 20 percent of the islands’ waters. The state legislature is considering a separate bill that would require fishing-free sanctuaries to be established along the state’s coast within three years. The concept of no-take zones, though controversial, is backed by enviros, the National Park Service, many scientists, the California Fish and Game Commission, California’s secretary for natural resources, and even some fishing groups.