Leaders | Marine management

Net positive

How to stop overfishing on the high seas

FISH are slippery characters, with little regard for international agreements or borders. The speediest, such as crescent-tailed bluefin tuna, can slice through the ocean at 70 kilometres per hour. Their routes take them beyond areas that come under the jurisdiction of individual coastal states, and into the high seas. These wildernesses were once a haven for migratory species. No longer.

Under international law the high seas, which span 64% of the surface of the ocean, are defined as “the common heritage of mankind”. This definition might have provided enough protection if the high seas were still beyond mankind’s reach. But the arrival of better trawlers and whizzier mapping capabilities over the past six decades has ushered in a fishing free-for-all. Hauls from the high seas are worth $16 billion annually. Deprived of a chance to replenish themselves, stocks everywhere pay the price: almost 90% are fished either to sustainable limits or beyond. And high-seas fishing greatly disturbs the sea bed: the nets of bottom trawlers can shift boulders weighing as much as 25 tonnes.

Introducing private property rights is the classic answer to this “tragedy of the commons”. That is the principle behind the exclusive rights given to coastal states to maintain territorial waters. A clutch of regional organisations have been set up to try to manage fish stocks in the high seas. But as a result of overlapping remits, vested interests and patchy data, the plunder continues apace (see article). Since 2010 the proportion of tuna and tuna-like species being overexploited has grown from 28% to 36%.

A fresh approach is needed. Slashing fishing subsidies is the most urgent step. In total these come to $30 billion a year, 70% of which are doled out by richer countries. By reducing fuel costs, subsidies bring the high seas within reach for a few lucky trawlers, largely from the developed world. Just ten countries, including America, France and Spain, received the bulk of the bounty from high-seas catches between 2000 and 2010, even though Africa has more fishermen than Europe and the Americas combined. That is unfair and short-sighted.

The next step is to close off more areas to fishing. As of 2014 less than 1% of the high seas enjoyed a degree of legal protection. A review of 144 studies published since 1994 suggests that to preserve and restore ecosystems, 30% of the oceans should be designated as “marine protected areas” (MPAs). Individual countries can play their part, by creating reserves within territorial waters: last year Britain created the world’s largest MPA, an area bigger than California off the Pitcairn Islands in the South Pacific. But to get anywhere near that 30% share, mechanisms must be found to close off bits of the high seas, too. The UN’s members have rightly agreed to work out how to do so.

Scaling up

Progress towards even these limited goals, let alone more ambitious ones such as a total ban on high-seas fishing, will not be easy. The fishing industry is adept at protecting its interests. Questions of governance and enforcement dog every effort to police the high seas. Demand for fish is rising: humans are each consuming 20kg on average a year, more than ever before.

So in parallel with efforts to protect wild stocks, another push is needed: to encourage the development of aquaculture, the controlled farming of fish. In 2014, for the first time, more fish were farmed for human consumption than were caught in the wild; farmed-fish output now outstrips global beef production. Unfortunately, feedstocks are often poor and storage facilities inadequate. By boosting basic research and infrastructure for aquaculture, governments could hasten a welcome trend. Eventually, efficient fish-farming will be the best guardian of stocks on the high seas.

This article appeared in the Leaders section of the print edition under the headline "Net positive"

Donald Trump and a divided America

From the July 16th 2016 edition

Discover stories from this section and more in the list of contents

Explore the edition

Discover more

Russia is gearing up for a big new push along a long front line

Ukraine must prepare

Antarctica needs a lot more attention

Melting ice sheets do more than raise sea levels


Some advice to the corporate world’s know-it-alls

With growth slowing, consulting firms like McKinsey need some counsel of their own