WE’VE devoted lots of column inches over the last few years to the threats various forms of commercial fishing pose to our apex predators. Marlin, swordfish, tuna and sharks … they’re variously targeted internationally by purse seiners, long liners, pole fishers and shark finners.
By international standards our management of these fisheries is middling. We “manage” catch rates but still allow fishing for species where we know nothing about stock status (broadbill swordfish), where by-catch impacts important non-commercial species (black and blue marlin, various shark species) and where stocks have obviously and visibly declined dramatically (various tunas, including southern bluefin, big-eye and yellowfin).
Despite our continued claims of being “one of the best in the world for sustainable fisheries management” we’re still behind assorted South American countries on apex predator protection, and precious few of our fisheries have achieved Marine Stewardship Council (MSC) certification. We still set trigger points related to reduced catches before taking action on many commercially overfished species, rather than really proactively managing fisheries and stocks before they start to crash.
The MSC recently co-funded a CSIRO study to look at not the big, sexy species but the little forage fish such as anchovies, sardines, herring, mackerel and krill. Offshore fishos have known for years that abundance of bait or forage species directly impacts numbers of pelagic “targets”. They’ve tried to get big scale commercial targeting of bait fish species on to the decision making agenda but have lacked “scientific evidence”.
Now the results of what is described as “the first major study of the ecosystem effects of fishing forage species” are in. It’s reported that forage fish account for more than 30 per cent of global fisheries production, for either use directly as human food or as livestock feed. Findings include that predator fish species, marine mammals and sea birds are all heavily affected by currently levels of forage fishing, with some ecological groups declining by up to 60 per cent.
It’s also suggested that halving fishing rates for heavily impacted forage species would still result in 80 per cent of the maximum sustainable harvest being achieved. This in turn could improve yields for other commercial species feeding on these forage fish. The Team Leader, the CSIRO’s Dr Tony Smith, said that adoption of this level of reduction could be combined with other management measures, such as closing areas to harvesting near marine mammal and seabird breeding colonies, to achieve ecological objectives while ensuring forage fish continue to contribute to global food security, both directly and indirectly.
Sounds like a good evidence-based science-driven plan … way better than just locking up areas in reserves and basically hoping that that conservation approach will work.
John Newbery is Environment Editor for Fishing World.
