The Big Loophole: The High Seas and Highly Migratory Fish
As individual countries have asserted sovereignty over their exclusive economic zones, some nations have seen their local fisheries improve. But this nationalization of the near shore has in some senses merely shifted the problem of overfishing from near shore to offshore environments. Nations have jurisdiction over their territorial waters out to 200 nautical miles, but beyond that limit is what is known as the “high seas” – international waters owned by no one but fished by many. As a result, high seas fishing has increased much more quickly than have all other types of fishing, by some estimations by as much as 800 percent.
The most notable increase has occurred on those 23 species of the taxonomic family Scombridae -- known commonly as “tuna” – fish that range the open ocean and which may migrate hundreds if not thousands of kilometers during the course of their lives. Tuna and other highly migratory species are managed through international organizations called regional fisheries management organizations (RFMOs). In all, there are 17 RFMOs, each with a mandate to manage a given section of the world. But as the map below reveals, these areas are vast and it is unclear to date whether management has been effective.
Tuna and all high seas fisheries are also deeply affected by what is referred to in governmental circles as illegal, unregulated and unreported (IUU) fishing. Also known as “pirate fishing,” IUU fishing takes place outside management regimes and severely disrupts any attempts made to rationalize global fisheries. Up to $23.5 billion in fisheries wealth is lost to IUU fishing every year, and the total illegal catch may be as high as 20 percent of all fish caught globally.
The other fishery where high seas and IUU issues are of great concern are in the waters surrounding Antarctica, often viewed as one of the final frontiers of fishing. Currently Antarctic waters are governed by an RFMO called the Commission for the Conservation of Antarctic Marine Living Resources. In the past IUU fishing for the high value Antarctic and Patagonian toothfish of the genus Dissotichus, (more commonly known as Chilean Sea Bass) have been notable. The Antarctic krill fishery (Euphausia superba) is also one that concerns ecologist, not only because fishing is difficult to regulate in the Southern Ocean, but also because krill are a keystone prey species for fish and marine mammals. Krill are increasingly being harvested to supply the dietary supplements industry as well as the aquaculture industry.