Nearly All Deep-Sea Fisheries Are Unsustainable

Deep-sea fishing, particularly bottom trawling, is one of the most destructive and inefficient ways of fishing. Though it provides less than 1% of seafood consumed globally, fishing fleets looking to capitalize on previously unexploited deep-sea fisheries are moving further and further off-shore, sometimes trawling in waters more than a mile deep.

In doing so, they destroy fragile deep water ecosystems, which are extremely slow to recover. Many species of fish and other marine life at these depths are characterized by long life spans and slow reproduction, making them extremely vulnerable to modern mechanized fishing practices like trawling – the equivalent of bulldozing the seafloor. Deep-water corals – some of which have been alive more than 4,000 years – sponges, and other animals are ripped from depths and then discarded as waste. Species targeted by deep water trawling, such as the orange roughy, are particularly at risk, as entire populations can be wiped out in a single season

A new comprehensive analysis of deep-sea fisheries, conducted by a team of leading marine scientists and published in Marine Policy, has sounded the alarm on the unsustainability of this practice ahead of the upcoming UN decision on whether to allow deep sea fishing to continue on "high seas." The study documents the collapse of deep sea fisheries around the world, including sharks and orange roughy. Other commercially caught deep-sea fishes include grenadiers (rattails) and blue ling.

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, according to Dr. Rashid Sumaila, an author and fisheries economist at UBC.

The authors of this Marine Policy paper say that 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," says Dr. Elliott Norse, the study’s lead author. "Deep-sea fishes are in deep trouble almost everywhere we look. Governments shouldn’t be wasting taxpayers’ money by keeping unsustainable fisheries afloat."