Managing Atlantic marlin as bycatch under ICCAT. The fork in the road: recovery or collapse

Abstract

Atlantic billfish (marlin, sailfish and spearfish) are managed under the jurisdiction of the International Commission for the Conservation of Atlantic Tunas (ICCAT). Because they are not commonly a target species, most fishing mortality is generated as a function of bycatch in various commercial fisheries. Billfish are very important species for recreational fisheries. The record indicates that ICCAT has placed its greatest emphasis on managing target fish to maximize their catch for ‘food purposes’ and has not placed the same level of emphasis on maximizing catch for ‘other purposes’, such as for the benefit of recreational fisheries.

Stock assessments indicate Atlantic marlin are severely overexploited, with the rates of decline showing no signs of slowing. The primary source of billfish mortality is as bycatch in pelagic longline fisheries for tuna and swordfish. Simultaneous fishing mortality rates that will produce maximum sustainable yield (MSY) for at least one targeted tuna species is near the extinction rate for blue marlin. Failure to significantly reduce fishing mortality on marlin by restraining effort on target species has led to the collapse of both blue and white marlin stocks and, if continued indefinitely, may lead to extinction of either species. Although ICCAT's charter does not prioritize management between different types of fisheries, commercial or recreational, or among different species of fish within its authority, the de facto result of ICCAT's actions to date has relegated billfish to the role of bycatch species. The needs of the directed recreational billfish industry have been largely ignored.

In the absence of responsible action by ICCAT to reduce fishing mortality on marlin, those concerned with the conservation of billfish will be forced to seek alternative conservation and management assistance through The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and other protected species options. Compatible management solutions now must be identified and implemented by ICCAT if diverse fishing interests are to coexist and the stocks are to return to MSY. Time and area closures and live releases, coupled with some restraints on targeted effort, may offer a solution most acceptable to all fishing interests.