California’s salmon will have additional protections from toxic insecticides under a new settlement agreement approved last month between the Environmental Protection Agency and environmental groups including Turtle Island Restoration Network. No-spray buffer zones now protect salmon and steelhead habitat 300 feet for pesticides applied from the air, and 60 feet if applied on the ground. The chemicals can harm the fish by poisoning them, destroying their habitat, impairing their ability to swim or navigate or cutting off their food supply of insects. Todd Steiner, T.I.R.N.’s executive director, called the agreement a “clear victory” and “way more cost effective than trying to clean up the mess after the fact.” The buffers reinstate protections mandated by a judge in 2004 that had expired after inaction by the E.P.A. Along with Earthjustice and Northwest Center for Alternatives to Pesticide, T.I.R.N. and others filed a lawsuit in 2010 seeking permanent barriers to spraying near sensitive streams and waterways. The settlement bans five chemicals, some of which were derived from nerve toxins developed during World War II, and applies to habitats in California, Oregon and Washington. “It’s kind of a no-brainer that salmon and pesticides don’t mix,” said Jason Rylander, of Defenders of Wildlife.