The 2011 required year-round use of weak hooks (15/0 carbon vs 16/0 steel for regularly used hook) by pelagic longline vessels fishing in the Gulf of Mexico was for 12 months, but it is now reduced to 6 months (Jan. – June). Longline hooked large bluefin tuna and blue marlin often broke off the weak hooks, reducing bycatch mortality, but a greater number of both white marlin and blue marlin were hooked. The weak hook research indicates that most marlin were released within 5 minutes.
In 2011, 175 white marlin were reported hooked by pelagic longline gear rigged with weak hooks (15/0 carbon) in the Gulf of Mexico, but the year after the weak hook implementation 521 were reported. Reported blue marlin hooked with weak hooks in 2011 was implemented was 152, but the following year, the number rose to 484, but numbers for each dropped over the next 5 years. Whether anglers will experience a lower interaction rate with marlin between July through September when weak hooks are not required is a concern if more marlin are discarded dead after being hooked on regular (16/0 stainless) hooks.