Australasian Science: Australia's authority on science since 1938

Closing the High Seas Opens Fishing Opportunities

By Reg Watson

Closing international waters to fishing would have little or no effect on global catches but make fishing potentially fairer, safer, better-managed and less polluting.

Following the establishment of the United Nations Convention on the Law of the Sea (UNCLOS) in 1982, the world’s maritime countries made moves to claim sole control over ocean resources in Exclusive Economic Zones extending 200 nautical miles (370 km) of their coastlines. Most of the resources that these nations took were close to shore and in the relatively shallow depths of the continental shelves. It was here that such activities as mineral exploration and oil drilling were possible.

Most fishing also occurred in coastal waters. Almost all fisheries were pursued close to shore where fish stocks were most abundant. Here plankton that supports the marine food web bathes in the sunshine of shallow waters and uses the nutrients either running from rivers or in large ocean upwellings of cool, rich waters.

There was usually no need to travel huge distances from ports and risk profits or lives. Apart from a few rich fisheries, such as the cod off the east coast of Canada and the United States, which has drawn long-distance fleets from Europe for centuries, most fishing was by national fleets in their own coastal waters.

So what changed? The ability to safely and profitably fish the high seas improved with technology, and the depletion of some inshore stocks pushed fishing companies to explore farther afield. By the 1970s, many fleets had left their national coastal waters and fished near other nations’ shores. This began to cause big problems that the declaration of Exclusive Economic Zones was meant to solve. If you did not use your coastal resources you could sell them to your neighbours. Nothing would be wasted.

One of the main fisheries in the high seas is for tuna. Although tuna spend some time inshore, large capacity was developed to take these valuable fish on the high seas. In fact, if you could fish them outside the waters of another country you could avoid paying access fees to fish in that country’s waters.

Coastal marine resources have always been important, especially to smaller countries without manufacturing or mining and especially if they support local agriculture by augmenting food security. Money derived from foreign fleet access could be used to offset other costs. Sometimes countries might have to allow access in return for foreign aid, but all parties could be winners if the trade-off was fair.

But if the high seas were closed to fishing, how much fish catch would be lost? Which countries would be winners and which would be losers?

A study we published recently in Nature Scientific Reports asked these questions by carefully mapping global catches and determining their value. Our findings were surprising. Overall there would be very little or no loss of catch, so no one would go hungry. The fish would instead be caught profitably in local national waters, and local management of these fish stocks would be improved. The fishers would potentially be safer and work under national guidelines.

The fleets would also use less fuel if they travelled less. Currently they account for more than 1% of annual global fuel consumption, so this could make a significant impact to climate change.

Most interesting was the finding that small island nations would control more of the fish stocks that frequented their waters. Instead of tuna stocks being taken before they arrived in a country’s waters by high seas fleets, they would be taken under licence in the country’s waters and sometimes by their own fleets.

Under current arrangements, many countries do not have the option to have their own national fishing fleet contributing to food security. There is no way to build this capacity when they do not have a guaranteed resource to support it. Closing the high seas would ensure that these countries are more self-sufficient and better prepared in their food security against climate change impacts, and overall give them a better and fairer deal.

Is this more than a thought experiment? By definition the high seas is beyond national jurisdictions and notoriously hard to deal with. Implementing such closures would require not just international cooperation and the latest high-tech satellite surveillance but, in all likelihood, would be expensive to enforce. It would require reform of ocean governance through agreements added to UNCLOS with support from conventions like the Convention on Biological Diversity.

Perhaps another more practical approach would be to have this market-driven by consumers. If accreditation of species like tuna taken in national waters improved their market value we could provide a stimulus to the industry to move in the right direction.

Projected winners would be Australia and its neighbours; losers would include some European countries and nations with wide-ranging fleets. But with no loss of catch, closing the high seas would make fishing potentially fairer, safer, better managed and less polluting. It’s time to start the dialogue.

Reg Watson is Professor of Fisheries and Ecological Modelling at the Institute for Marine & Antarctic Studies, The University of Tasmania.