50 C.F.R. § 660.506
The only fishing gear authorized for use in the reduction fishery for northern anchovy off California are round haul nets that have a minimum wet-stretch mesh size of 10/16 of an inch (1.59 cm) excluding the bag portion of a purse seine. The bag portion must be constructed as a single unit and must not exceed a rectangular area, adjacent to 20 percent of the total corkline of the purse seine. Minimum mesh size requirements are met if a stainless steel wedge can be passed with only thumb pressure through 16 of 20 sets of 2 meshes each of wet mesh. The wedges used to measure trawl mesh size are made of 20 gauge stainless steel and will be no wider than 10/16 of an inch (1.59 cm) less one thickness of the metal at the widest part.
50 C.F.R. §660.506