By Chris Howe

My experience of tuna growing up in the sixties and seventies was: a tasty fish, nice in sandwiches, and comes in a tin. This was a far cry from the deep red slices you can see in the sushi bar. I’ll never forget the first time I actually saw a tuna, on television - a huge, fish, shiny and sleek, speeding through the world’s oceans. And then, long lines of them on the floor of a Japanese fish market, fetching tens of thousands of dollars each. It seemed almost inconceivable that these huge animals were similar to fish we found in small tins on the supermarket shelf.

Over the past few decades tuna fisheries have had their fair share of attention. Perhaps the first big concern was the accidental killing of dolphins in tuna nets in the eastern Pacific. As long ago as 1990, the US Department of Commerce established a label certifying tuna that was “dolphin friendly”. Many other dolphin friendly tuna labels followed, as a response to public concern.

Then, in the early 2000s, the issue of mercury contamination in tuna came up. Because tuna are large, are top predators – i.e. they eat other fish – and live for a relatively long time, they accumulate more pollutants than smaller fish lower down the food chain. Other big fish, such as swordfish and marlin, have the same problem.

And it is their place at the very top of the food chain that gives us a clue about their importance in the ocean’s ecosystem. Top predators are critical to the health of the ocean – indeed, the health of any ecosystem. Without them, the whole system becomes unbalanced. Despite this, the world’s tuna fisheries continue to harvest bluefin and yellowfin tuna at unsustainable rates.

You would think that in 2010, we’d understand enough to control the boats taking these magnificent creatures, at the very least so that we can leave enough in our oceans to ensure we can continue to catch them in the future, as well as to ensure our oceans remain healthy. But despite several intergovernmental agencies being set up to manage various aspects of the world’s ocean, including some specifically focussed on tuna, scientists estimate that up to 90 percent of the ocean’s top predators have been lost.

That’s why, last week, many governments and environmental organisations were campaigning hard at the latest meeting of the Convention on International Trade in Endangered Species (CITES – pronounced sigh-tees) for a ban on international trade in Atlantic bluefin tuna – the most highly valued and one of the most threatened of the tuna species. WWF believes that the Mediterranean population of Atlantic bluefin tuna is close to collapse, and the southern bluefin, found in our waters, fares even worse.

Bluefin tuna stocks have been devastated because the management agencies have set excessive quota (often ignoring scientific advice) and because of illegal fishing. This is where boats catch fish that they have no quota for, and then sell it illegally into markets around the world. As a result, far more fish are caught than the populations can sustain and bluefin tuna has ended up on the endangered species list.  Why is this? Well, a 2008 review of the body that manages the international Atlantic bluefin tuna fishery (known by the catchy name ICCAT) found that it failed in its job because it did not monitor the fishery properly.

So, if you like, the campaigning last week was a last ditch effort. If the international bodies don’t work, then let’s try banning international trade, the argument goes. Unfortunately, but not surprisingly, certain governments weren’t having any of it. Seventy-two countries, led by Libya, with support from Japan and Canada– which has obviously learnt nothing from the collapse of the Newfoundland cod fishery twenty years ago – voted down the proposal.

And New Zealand? We voted against the ban as well. Now why would that be?

Well, southern bluefin tuna is in as bad a state as the Atlantic bluefin. Stocks are below 5 percent of their original levels. Could the New Zealand government be worried that southern bluefin would be next in line for a ban if the vote on Atlantic bluefin had gone through? Scientific advice to the Commission charged with managing southern bluefin says that only zero catches would allow the stock to recover, and even then it would reach only 20 percent of its original level by 2030. Yet the New Zealand government has proposed to raise the New Zealand quota for southern bluefin.

The only conclusion I can draw from this behaviour is that someone in the New Zealand government has an overwhelming sense of misplaced loyalty to the fishing industry. Because voting down a trade ban for Atlantic bluefin tuna more or less condemns it to commercial extinction. And not dramatically reducing the quota for southern bluefin, against the scientific advice, does the same.

It would be a tragedy to lose such a magnificent species – the marine equivalent of, say, the cheetah – but much worse would be the imbalance such a loss would cause across the world’s oceans. And bluefin tuna range the world’s oceans, navigating thousands of kilometres every year across huge areas of sea with an accuracy that would put most sailors to shame. They are truly one of the world’s most incredible creatures.

New Zealand is complicit in this wholly irresponsible behaviour, which – along with the ongoing decline in all kiwi populations, the devastation of Hector’s dolphins dying in fishing nets, and the scant and ineffectual policies on climate change – removes yet another coat of our green veneer.  The world has started start to see the true colour of New Zealand’s environmental reputation and it’s certainly not as pretty as we’d have them believe.