(a) Mesh restrictions and exemptions. Vessels subject to the mesh restrictions in this paragraph (a) must render any net, or any piece of net, with a mesh size smaller than that specified in paragraphs (a)(1), (2), and (3) of this section not available for immediate use as defined in § 648.2.

(1) Butterfish fishery. Owners or operators of otter trawl vessels possessing more than 5,000 lb (2.27 mt) of butterfish harvested in or from the EEZ may only fish with nets having a minimum codend mesh of 3 inches (7.62 cm) diamond or square mesh, as measured by methods specified in § 648.80(f), applied throughout the codend for at least 100 continuous meshes forward of the terminus of the net, or for codends with less than 100 meshes, the minimum mesh size codend shall be a minimum of one-third of the net, measured from the terminus of the codend to the headrope.

(2) Longfin squid fishery. (i) Owners or operators of otter trawl vessels possessing longfin squid harvested in or from the EEZ may only fish with nets having a minimum mesh size of 2 1/8 inches (54 mm) during Trimesters I (Jan-Apr) and III (Sept-Dec), or 1 7/8 inches (48 mm) during Trimester II (May-Aug), diamond or square mesh, as measured by methods specified in § 648.80(f), applied throughout the codend for at least 150 continuous meshes forward of the terminus of the net, or, for codends with less than 150 meshes, the minimum mesh size codend shall be a minimum of one-third of the net measured from the terminus of the codend to the headrope.

(ii) During closures of the longfin squid fishery resulting from the butterfish discard cap, described in § 648.24(c)(3), vessels fishing for longfin squid using jigging gear are exempt from the closure possession limit specified in § 648.26(b), provided that all otter trawl gear is stowed and not available for immediate use as defined in § 648.2.

(3) Net obstruction or constriction. Owners or operators of otter trawl vessels fishing for and/or possessing butterfish or longfin squid shall not use any device, gear, or material, including, but not limited to, nets, net strengtheners, ropes, lines, or chafing gear, on the top of the regulated portion of a trawl net except any of the following materials may be used as specified:

(i) Splitting straps, and/or bull ropes or wire around the entire circumference of the codend provided these materials do not obstruct or constrict the top or the trawl net while it is being towed;

(ii) Net strengtheners (covers) that do not have a mesh opening of less than 5 inches (12.7 cm) diamond or square mesh, as measured by methods specified in § 648.80(f); and

(iii) A liner may be used to close the opening created by the rings in the aftermost portion of the net, provided the liner extends no more than 10 meshes forward of the aftermost portion of the net, the inside webbing of the codend shall be the same circumference or less than any strengthener and the liner is no more than 2 ft (61 cm) longer than any net strengthener.

(4) Top of the regulated portion of the net means the 50 percent of the entire regulated portion of the net that would not be in contact with the ocean bottom if, during a tow, the regulated portion of the net were laid flat on the ocean floor.

(5) Illex fishery. Seaward of the following coordinates, connected in the order listed by straight lines except otherwise noted, otter trawl vessels possessing longfin squid harvested in or from the EEZ and fishing for Illex during the months of June, July, August in Trimester II, and September in Trimester III are exempt from the longfin squid gear requirements specified in paragraph (a)(2) of this section, provided that landward of the specified coordinates they do not have available for immediate use, as defined in § 648.2, any net, or any piece of net, with a mesh size less than 1 7/8 inches (48 mm) diamond mesh in Trimester II, and 2 1/8 inches (54 mm) diamond mesh in Trimester III, or any piece of net, with mesh that is rigged in a manner that is prohibited by paragraphs (a)(2) and (a)(3)(ii) of this section.

(6) Mackerel, squid, and butterfish bottom trawling restricted areas—(i) Oceanographer Canyon. No permitted mackerel, squid, or butterfish vessel may fish with bottom trawl gear in the Oceanographer Canyon or be in the Oceanographer Canyon unless transiting. Vessels may transit this area provided the bottom trawl gear is stowed and not available for immediate use as defined in § 648.2. Oceanographer Canyon is defined by straight lines connecting the following points in the order stated (copies of a chart depicting this area are available from the Regional Administrator upon request):

(ii) Lydonia Canyon. No permitted mackerel, squid, or butterfish vessel may fish with bottom trawl gear in the Lydonia Canyon or be in the Lydonia Canyon unless transiting. Vessels may transit this area provided the bottom trawl gear is stowed and not available for immediate use as defined in § 648.2. Lydonia Canyon is defined by straight lines connecting the following points in the order stated (copies of a chart depicting this area are available from the Regional Administrator upon request):

(b) [Reserved]

(c) Mesh obstruction or constriction. The owner or operator of a fishing vessel shall not use any mesh construction, mesh configuration, or other means that effectively decreases the mesh size below the minimum mesh size, except that a liner may be used to close the opening created by the rings in the aftermost portion of the net, provided the liner extends no more than 10 meshes forward of the aftermost portion of the net. The inside webbing of the codend shall be the same circumference or less than the outside webbing (strengthener). In addition, the inside webbing shall not be more than 2 ft (61 cm) longer than the outside webbing.