Sustainability of deep-sea fisheries

In a comprehensive analysis published in the journal Marine Policy, marine ecologists, fisheries biologists, economists, mathematicians and international policy experts show that, with rare exceptions, deep-sea fisheries are unsustainable.  The “Sustainability of deep-sea fisheries” study, whose primary author is Marine Conservation Institute Founder and Chief Scientist Dr. Elliott A. Norse, decides whether to continue allowing deep-sea fishing in international waters, which the UN calls “high seas.”

Life is mostly sparse in the oceans’ cold depths, far from the sunlight that fuels photosynthesis.  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 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. 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 seafood.  But fishing there, especially bottom trawling, causes profound, lasting damage to fishes and life on the seafloor, such as deep-sea corals.

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

The article documents the collapse of many deep-sea fishes around the world, including sharks and orange roughy.  Other commercially caught deep-sea fishes include grenadiers (rattails) and blue ling.

Fifty years ago no one ate orange roughy, In fact, it used to be called slimehead, indicating no one ever thought we would eat it.  But as we’ve overfished our coastal species, that changed and so did the name.

Orange roughy take 30 years to reach sexual maturity and can live 125 years.  Compared with most coastal fishes, they live in slow-motion.  Unfortunately for them and the deep-sea corals they live among, they can no longer hide from industrial fishing.

With slow-growing fish, there’s economic incentive to kill them all and reinvest the money elsewhere to get a higher return-on-investment.  Killing off life in the deep sea one place after another isn’t good for our oceans or economies.  Boom-and-bust fisheries are more like mining than fishing.

The lawlessness of the high seas adds to overfishing in the deep.  So do nations’ fisheries subsidies.

High seas trawlers receive some $162 million each year in government handouts, which amounts to 25% the value of the fleet’s catch.

The best policy would be to end economically wasteful deep-sea fisheries, redirect subsidies to help displaced fishermen and rebuild fish populations in productive waters closer to ports and markets, places far more conducive to sustainable fisheries.

Instead of overfishing the Earth’s biggest but most vulnerable ecosystem, nations should recover fish populations and fish in more productive coastal waters.  Deep-sea fishes are in deep trouble almost everywhere we look.  Governments shouldn’t be wasting taxpayers’ money by keeping unsustainable fisheries afloat.

Project Overview - Sustainabilty of deep-sea fisheries
Summary - Are deep-sea fisheries sustainable?
Graphic- A look at deep-sea bottom trawling
Full Article - Sustainability of deep-sea fisheries in Marine Policy
Video - Fished Out
Washington Post Article - Scientists call for end to deep-sea fishing