Underwatertimes.com News Service - February 12, 2015 21:02 EST

The world's high seas should be closed to fishing argues a new study in the journal Scientific Reports, co-authored by Isabelle Côté, a Simon Fraser University professor of marine ecology and conservation.

"Intense fishing in the high seas has resulted in habitat destruction and declining stocks of fish such as tunas and swordfishes," says Côté.

In the study Côté and her colleagues analyzed the economic impact of closing the high seas to fishing, identifying which countries would stand to financially gain or lose.

The world's oceans are separated into exclusive economic zones (EEZs) and the high seas. EEZs are the coastal areas that are within 200 nautical miles of maritime countries that maintain the rights to the resources in these waters. The high seas are international waters outside of these boundaries that are shared by the world.

For the first time, the authors estimated the amount of fish caught in the high seas as opposed to EEZs. According to their study, less than one per cent of the global landings come from fish caught only in the high seas. The bulk of the world's fisheries actually come from fish stocks that straddle both areas. This unexpectedly high level of exchange means that most fish stocks would still be available to be fished in EEZs, even if the high seas were closed to fishing.

The authors then evaluated the impact of closing deep-sea fishing on fisheries' catches and values, and their economic consequences for individual countries.

"Under realistic assumptions, closing the high seas would result in no loss in fish catches or landed value of them on a global scale," says a surprised Côté. "Of course, a few countries would lose out, but most would gain, including some of the world's poorest countries."

Commenting on the United Nations' recent decision to consider creating a legally binding agreement to protect international waters, Côté says: "I hope our research increases understanding of the need for this. I am delighted that the high seas are starting to be recognized as a valuable resource that deserves protection and stewardship."

The Global Ocean Commission, OceanCanada and the Social Sciences and Humanities Research Council of Canada funded this study, which was led by U. Rashid Sumaila at the University of British Columbia.