Each year, fishing fleets that now include more than 1.3 million commercial vessels remove about 80 million tonnes of fish and invertebrates from the global ocean1. This catch contributes roughly 16% of the animal protein consumed around the globe, and provides essential nutrition for billions of people2.

Industrial fishing now takes place throughout the global ocean on a scale that has expanded substantially over the last few decades. Nets of increasing size and sophistication and lines up to 60km long with baited hooks are deployed across the high seas. Bottom-trawlers drag gear weighing many tonnes across the seafloor3, causing permanent damage to ancient ecosystems4 in a single traverse. Fish aggregation devices (FADs)5 are left floating for days, drawing in target and non-target species, which can be scooped up en masse. In areas beyond national jurisdiction, species such as Antarctic krill6 are being pursued for food supplements, animal feed and biomedical uses.

Illegal, unreported and unregulated (IUU) fishing is especially pernicious. Vessels sailing under flags of convenience7, without the requirement to carry an International Maritime Organization identification number or a recognised monitoring system, are able to operate virtually anywhere on the high seas without fear of apprehension. There are no constraints on what equipment they use, where and when they fish, or how much they catch. By definition, no-one knows the size of their haul, though it is estimated to be about one-fifth of the global total8.

Evidence shows that much of the global ocean has been fished to dangerously low levels. About a third of commercial fisheries are over-exploited and a further half fully exploited9. Ninety percent of many stocks of the world’s large fish (such as tuna and swordfish) have disappeared10. Some stocks are at a tipping point, and may not recover. Across the oceans, fleets are devoting ever more effort to catching fish, yet catches are declining; the ocean simply has no more capacity to give.