WHY ALL TUNA FISHERIES CAN’T BE POLE AND LINE

Why all tuna fisheries can’t be pole and line. In a blog on the Marine Stewardship Council website, Bill Holden, MSC Senior Fisheries Manager for Oceania and South East Asia has outlined why it is not feasible for all tuna fisheries to be pole and line.

In his blog, he says: “Pole and line can be a great way to catch tuna. It’s clean and selective as the tuna are caught one by one, so there’s little bycatch of other species. It also provides a living for many thousands of artisan fishers, helping to preserve a traditional way of life.

“So it’s understandable that concerned consumers seek out tuna caught by pole and line. In northern Europe, campaigns highlighting unsustainable tuna fishing have led retailers to increasingly source pole and line tuna as a relatively low-impact source of tuna.

“Yet pole and line fisheries supply only around 10% of the tuna landed globally, mostly from Indonesia, Japan and the Maldives. And there’s little sign of this proportion increasing: despite the demand, we’re not seeing any large-scale public or private investment into expanding pole and line tuna fishing. In fact, in many places fisheries are struggling to recruit fishers as skilled pole and line fishers retire.

“The reality is that given the global consumer demand for tuna, pole and line is simply not an economically viable way to supply large volumes of tuna to the market. It’s much more labour intensive than other fishing methods, and while this may be good from a social perspective, it adds considerable cost. Pole and line boats also use more fuel per tonne of tuna than purse seine or longline vessels, putting a further squeeze on margins.

“There are other considerations to take into account. Pole and line yellowfin tuna fisheries have a high catch of juvenile yellowfin compared to long line and free school purse seine fisheries. Pole and line fishing also needs live bait, so the crew will have to spend extra fishing time catching that bait first. That’s assuming there are suitable bait-fishing grounds nearby – which is often the case in Indonesia and the Maldives, but less so in other areas.

“Bait fishing carries environmental and social implications too. The volume of bait required is equivalent to about 10% of the tuna catch by weight. Bait fish such as sardines are important both for their ecological role and for local food security, so it’s essential that bait fishing is done sustainably. Unfortunately, a lack of data in many fisheries, particularly in developing countries, can make it hard to assess whether this is the case.

“While there are several MSC certified pole and line tuna fisheries – including the Maldives, which supplies around a quarter of the global pole and line catch  – tuna fisheries using other methods have also been certified to MSC standard. That means that tuna from these fisheries is being fished at a sustainable level, impacts on marine ecosystems and other species are minimised, and the fisheries are well managed. Again, it’s important to keep in mind the sense of scale: while headline statistics show that purse-seine tuna fisheries have much higher volumes of bycatch than pole and line, they also produce a far higher volume of tuna. In fact, the proportion of bycatch  in the best-performing free-school purse-seine fisheries is similar to the bait requirements for pole and line fishing.

“So, while pole and line remains an important, relatively low impact fishing technique, it’s never going to supply the world’s tuna demand. That means our priority must be improving the sustainability of tuna fishing, whatever method is used.”

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