A team of leading marine¹ scientists from around the world is recommending an end to most commercial fishing in the deep sea, Earth's largest ecosystem². Instead, they recommend fishing in more productive waters nearer to consumers. In a comprehensive analysis published online in the journal Marine Policy, marine ecologists, fisheries biologists, economists³, mathematicians⁴ and international policy experts show that, with rare exceptions, deep-sea fisheries are unsustainable. The "Sustainability of deep-sea fisheries" study, funded mainly by the Lenfest Ocean Program, comes just before the UN decides whether to continue allowing deep-sea fishing in international waters, which the UN calls "high seas."

Life is mostly sparse⁵（稀疏的） in the oceans' cold depths, far from the sunlight that fuels photosynthesis⁶. Food is scarce and life processes happen at a slower pace than near the sea surface. Some deep-sea fishes live more than a century; some deep-sea corals can live more than 4,000 years. When bottom trawlers（拖网渔船） rip life from the depths, animals adapted to life in deep-sea time can't repopulate on human time scales. Powerful fishing technologies are overwhelming them.

"The deep sea is the world's worst place to catch fish" says marine ecologist Dr. Elliott Norse, the study's lead author and President of the Marine Conservation Institute in Bellevue, Washington USA. "Deep-sea fishes are especially vulnerable because they can't repopulate quickly after being overfished."

The deep sea provides less than 1% of the world's seafood⁷. But fishing there, especially bottom trawling, causes profound, lasting⁸ damage to fishes and life on the seafloor, such as deep-sea corals, these experts say.

Since the 1970s, when coastal⁹ fisheries were overexploited, commercial fishing fleets have moved further offshore¹⁰ and into deeper waters. Some now fish more than a mile deep.

"Because these fish grow slowly and live a long time, they can only sustain a very low rate of fishing," says author Dr. Selina Heppell, a marine fisheries ecologist at Oregon State University. "On the high seas, it is impossible to control or even monitor the amount of fishing that is occurring. The effects on local populations can be devastating¹¹."