Salmon may not be taken for commercial purposes in District 6 at the mouths of the Smith and Klamath Rivers within three nautical miles north and south of a line drawn due west for three nautical miles from the center of the mouth of each of those streams, or during the months of August and September in District 7 at the mouth of the Eel River within two nautical miles north and south of a line drawn due west for two nautical miles from the center of the mouth of that stream.