Last week I went to the chilly auction rooms at Auckland Fish Market to hear a talk billed as “the myth of overfishing” by fisheries scientist Ray Hilborn. Earlier in the day I’d spoken to a fisherman from Whakatane about their tuna tournament which had to be renamed after yellowfin ceased to be a feature of their catches. So, I was intrigued to hear how Hilborn intended to bust a myth when the evidence of its reality is right there on our coasts.

Surprisingly, Hilborn spent a great deal of his talk focusing on agriculture rather than fishing. There were photographs of land erosion, of large numbers of cows and of the rainforest ecosystem that originally covered land that is now being organically farmed. Now don't get me wrong – I firmly believe that there are problems with the way we are farming - in fact the impacts of agriculture led me to decide a couple of years ago to aim to eat meat just once a month. There are also major problems with the way we are fishing, and in both cases many of those problems can be overcome. But, as with many things, the first step is to admit you have a problem – and in a talk, entitled “the myth of overfishing”, there was precious little of that going on.

Hilborn accused the likes of Greenpeace of being “single issue” but, in fact, we have campaigns focused on addressing unsustainable practices in both industries, to make them into the world class examples we'd love them to be. The drivers of bad practices in both industries and many others are very similar: short term gain over long term sustainability. Failures include the use of imported palm kernel animal feed for our industrial dairy farming, which is affecting our land, rivers, climate and the rainforests of Indonesia. And, our reliance on destructive bottom trawling for fishing, where heavy nets basically plough the seabed taking anything in their path. The important thing is that the problems with our agriculture systems and our industrial fisheries can be fixed.

If Hilborn is to be believed, all fish are fine to eat ("New Zealand has never overfished its stocks") and not eating them would be an environmental disaster ("if everybody was to become vegetarians, more rainforest would have to go").

Missing from his comparison was the context: In NZ we had the foresight to set aside around 1/3 of our land as national parks and conservation land way back when agriculture, horticulture and forestry were developing. National parks, where all native plants and animals are protected. In comparison, we protect only around one per cent of our EEZ in marine reserves, the ocean equivalent of a national park. Had we set aside a similar proportion of our oceans when industrial fishing was in its early days, I don't think we'd be having the problems we are now.

For a fisheries scientist, Hilborn spent a long time talking about agriculture... which made me wonder what it was he didn't want to talk about from his own discipline. It also made me wonder whether the $2 million or so, he's received from the NZ seafood industry alone since 1990, might have something to do with his views - would the comparison be different if he was getting that money from the dairy industry rather than the fishing industry, do you think?

One of Hilborn's complaints was about how many fish species are red listed by groups like Greenpeace and Forest and Bird. But it's not about fishing being wrong, it’s about how we are fishing. In most cases we're not saying those species should never be fished - for goodness sake, many tuna are 'in the red' and these are a fast breeding species that can be caught with relatively low-impact methods (although often aren't now) - ideal fisheries, in theory! But, that we need to get tuna fisheries out of the red and into the green - by allowing the stocks to recover from their precarious state (as low as 4.6% remaining, and the case of southern bluefin) and change how we are fishing. The tuna longline fisheries in New Zealand catch more sharks than tunas! And when fish aggregating devices are used by purse seiners the by-catch increases by 5-10 times.

That pressure to improve how we are doing our fishing happens when people are informed about the problem and decide to be part of the solution by making the right choice about what they eat, how they run their business or what they catch. Making broad brush and completely untrue statements like "New Zealand has never overfished its stocks" on National Radio, as Hilborn did a couple of weeks ago, is a deliberate attempt to mislead the public and derail any progress on  sustainable fishing.  We have an opportunity to manage our fisheries better and return our oceans to health but we need a comprehensive network of marine reserves, not the tiny one per cent we have currently. Information on what species and what fishing methods to avoid needs to be widespread, and we should be embracing the moves by consumers, chefs, seafood brands and supermarkets to end the trade in unsustainably caught seafood.

In the UK, just after the “Fish Fight” programme was aired on TV, the tinned tuna giant Princes (the largest selling tuna brand in the UK) committed to shift its entire tuna source to pole and line and FAD-free tuna by 2014 - products that simply aren't available YET in New Zealand probably, in part, due to the line we are fed by the likes of Hilborn that “New Zealand has never overfished its stocks”. The first step comes when you admit you have a problem. Look at the evidence, 90 per cent of West Coast North Island snapper gone, scallops lost from Tasman Bay, Toheroa virtually unheard of any more, three stocks of orange roughy fished to collapse and closed, bluefin tuna at 4.6 per cent and classified as critically endangered... these are just the most extreme examples.

More demand for sustainably caught fish creates incentives for fishers to move towards methods that are better for the oceans. It enables shifts like that just made by Princes to occur, shifts that will have a considerable positive impact on reducing the amount of marine life dying as casualties in our fisheries, and bringing the stocks that our fisheries rely on out of danger. Now why would that be a bad thing, and why would a fisheries scientist cast aspersions on attempts to create that change?