Coles' canned yellowfin tuna – is it sustainable?

1 September 2015 | How an 'overfished' stock suddenly become okay to eat.

Is yellowfin tuna overfished?

Coles has recently started stocking a new range of canned yellowfin tuna, a species of tuna it previously didn't source because it said it was overfished.

The new tuna range appears to be in breach of its sustainable seafood policy. Coles has since taken the policy off its website. The 2015 policy read: "We do not source Yellowfin, Southern Bluefin or Bigeye tuna, all of which are overfished, or are in danger of being overfished."

So what's going on?

While it may be questionable for Coles to adjust its sustainable seafood policy on the fly, its new pole and line caught yellowfin tuna does in fact come from a Marine Stewardship Council (MSC)-certified fishery in the Maldives.

Can an "overfished" fish suddenly become sustainable? We spoke with MSC's Asia Pacific regional director Patrick Caleo and its senior fisheries manager for Oceania and Southeast Asia Bill Holden to find out how sustainable the tuna really is.

This particular fishery was certified for yellowfin tuna by MSC in 2014, prior to the sale of Coles' yellowfin tuna, Mr Caleo told CHOICE.

Yellowfin makes a comeback

While the stock was once subject to overfishing, this doesn't preclude it from ever being sustainable again. For example, yellowfin stocks were last assessed in 2012 by the intergovernmental organisation, the Indian Ocean Tuna Commission (IOTC), and were no longer deemed to be overfished in the region.

Quentin Hanich, associate professor and Fisheries Governance program leader at the University of Wollongong, says "for the time being, that's probably the best scientific evidence available, so you'd have to go with that."

Fish stocks can fluctuate for a number of reasons, says Caleo from MSC – be it naturally or as a result of fishing pressures. "Sustainable seafood policies do change," he says.

Yellowfin stocks in the region are due to be assessed again this year and if there is a drastic change, MSC will review the fishery's certification. MSC fisheries are certified for a period of five years, but are reviewed every year to ensure fish stocks are still healthy.

How are MSC fisheries certified and what does it mean?

When assessing a fishery MSC ensures:

  • fish stocks are healthy and robust;
  • the fishing methods used reduce the impact on the marine ecosystem; and,
  • the fishery is well managed and can respond to environmental changes.

MSC certification takes around 12–18 months. An independent auditor assesses fisheries against MSC's standard, and brands using the certification label are charged 0.5% of the net price.