That leads to seafood fraud and threatens fishing economies, seafood consumers and vulnerable marine species on a global scale.
Economic losses through fish piracy are estimated at $10-23 billion, while threatening 260 million jobs.
The world's largest ocean conservation group, Oceana says has just completed a major study of fish piracy.
Speaker:Margot Stiles, campaign director, Oceana
STILES: Well it is kind of a trip to find out what's not being reported because of course it's not reported. What we have found is that a number of different academics and governments have made an effort to compare what's being sold on the market to what's being reported as caught by the fishing boats. And when they don't add up, you know that fish is coming from somewhere so it means there's illegal fishing going on.
COUTTS: Well what's the flow-on from there, what happens now and the impact of this piracy and illegal fishing?
STILES: Well there is billions of dollars at stake, there's also direct cuts to profits for honest fishermen. An Australian example they have found that in the Gulf of Carpentaria the fishermen there were practising what they're supposed to be doing, were losing their profits, it's down about ten per cent because of the people that were fishing off the book.
COUTTS: Now is that close, it's a lot of money, ten to 23 billion dollar economic losses through this fish piracy?
STILES: Yes I mean it's remarkable, I think there are a number of species that are very high valuable where the pirates are focussing their efforts, that includes shark fins, it includes spiny lobster or crayfish and scallops. So there's a lot of money being made on the most valuable kinds of seafood.
COUTTS: And threatening 260 million jobs, that's worldwide, how much in the Pacific do we know?
STILES: I don't know the specific breakdown by region. But I do know that there are a lot of small island developing states in the Pacific that are very vulnerable to this kind of piracy. There's less enforcement resources and there are people that are directly depending on these fish for food.
COUTTS: So we don't really know whether the tuna industry's sustainable because we don't really know how much piracy is actually going on?
STILES: That's true.
COUTTS: So what does it say about the sustainability of the industry?
STILES: Well I think one concern is even with the fisheries that are officially reported, more than 80 per cent of the fisheries that are officially reported to the United Nations are either maxed out, they're fully exploited or they're over-exploited and in decline. So if we think it's 80 per cent over-fishing, we don't have any room to grow, and then we find out on top of all of that there's additional illegal fishing, it's really concerning about the sustainability of fisheries as a whole.
COUTTS: And the flow-on effect too, the illegal nature of it, seafood fraud, does that mean that the fish being sold in our markets isn't being labelled correctly, because if it is it might highlight the illegal nature of it?
STILES: Yes I mean we have already found that there's a lot of seafood fraud going on, there's depending on the product there could be ten per cent or 30 per cent or more of the fishes being mislabelled. And previously Oceana's research on this involved DNA testing, and we're assuming that people are trying to make a little bit of extra money, maybe they put an extra dollar on the price of cod. But actually in some cases this is happening because one fish that's illegally caught is being substituted for something else.
COUTTS: Well what does it say about the industry now and where to from here, what needs to be done to try and reduce the amount of piracy that's happening in the industry?
STILES: Well one thing that has been happening is that some of the sectors of the industry that are being hurt by this kind of corruption are calling for more traceability of the food supply. So just as in other kinds of when there's a food safety scare in produce or when there's concern about other kinds of meat, there's been an increase in tracking of the food from its source to the plate. We'd like to see that for fish. And there's some industry leaders that have already done that for their own product, but we'd like to see governments require that so that when you get your fish, it comes with a barcode that can be traced all the way back and you can tell that there hasn't been any substitution going on or fraud along the way.
COUTTS: How far off is that?
STILES: Well I think the European Union has already done it, they've required increased documentation for any imports to the European Union, which is a big player in the market. They're still several large markets after that, there's the US market and there's China. And there's still a long way to go to try and get traceability for those larger seafood markets. And certainly in a smaller market it's easier to get control of the supply. So we're optimistic that other countries will also lead the way.
COUTTS: How adequate are the penalties for those caught fishing illegally?
STILES: Well that is actually one of the most dramatic disparities is that we've seen in specific cases the profit to be made from illegal fishing is huge and the penalty is a tiny percentage of what could be made. So if someone is in the business of poaching, the penalties are almost just a very small tax, they're really not a deterrent. There is an expert from Australia at the Institute of Criminology that had done a study of many crimes associated with fishing and including illegally caught seafood, and that's one of the things that was highlighted that the penalties are simply not enough to deter criminal behaviour.