As coastal and open-water pelagic fisheries have become ever more heavily exploited and depleted, industrial fishing vessels have increasingly turned to exploiting deep sea species. The primary method of deep sea fishing is bottom trawling, which is among the most destructive. Today’s trawlers are capable of fishing seamounts, deep sea canyons and rough seafloor – areas that were once avoided for fear of damaging nets. To capture one or two target commercial species, deep sea bottom trawl fishing vessels drag huge nets armed with steel plates and heavy rollers across the seabed, pulverizing everything in their path. In order to catch a few “target” fish species of commercial value, biologically rich and diverse deep sea ecosystems such as seamounts are plowed through, often crushing corals, sponges and other benthic structures and lifeforms as they go.
The scale of the threat to the deep sea’s biodiversity as a result of bottom trawling and other methods of deep sea fishing is as yet unknown. However, it is potentially comparable to the threat to terrestrial biodiversity associated with the loss of tropical rainforests. Many thousands of species may be at risk, most of which are still unknown to science. Fragile deep water ecosystems, coral systems in particular, stand no chance against the ruthlessly effective underwater “bulldozers”. Deep sea structures are not merely damaged: they are obliterated in a manner akin to clear-cutting a rainforest. After heavy trawling, coral ecosystems on seamounts are reduced to mostly bare rock and coral rubble. Once destroyed, slow-growing deep sea species are unlikely to recover for decades or centuries, or even lost forever. Stable living habitats such as coral and sponge communities tend to be both the most heavily damaged and the slowest to regenerate.
In addition to the physical impacts of bottom fishing on deep sea ecosystems, the depletion of deep sea species is a matter of international concern. Unlike shallow-water species, deep-sea species are often slow-growing, long-lived, “low productivity” species that are highly vulnerable to depletion. Most high seas bottom fisheries target low productivity species such as orange roughy in the South Pacific and Indian Oceans, grenadiers in the Northeast Atlantic, redfish in the Northwest Atlantic, and deep-sea sharks (often caught as bycatch in deep-sea fisheries in the Atlantic, Pacific and Indian Oceans and marketed to the cosmetics and dietary supplement industry for their liver or “squalene” oil).
In addition, a large number of species have been recorded in the bycatch of many high seas bottom fisheries, in particular bottom trawl fisheries, the majority of which are likely to be low productivity species. The status of target and bycatch species in the deep sea fisheries on the high seas is largely either unknown or, where information is available, considered overexploited or depleted. Regulations are in place in some high seas fisheries to manage the target catch in deep-sea fisheries. However, few, if any, of the fisheries impacting deep sea stocks or species on the high seas can currently be considered sustainable.
Not only are deep sea fisheries for the most part unsustainable but the economics of deep sea fisheries are questionable given the low productivity of deep sea fish stocks. A study released in 2007 by the Fisheries Centre of the University of British Columbia concluded that many deep sea bottom trawl fisheries on the high seas in recent years would not have been economically viable without state subsidies. A review of deep sea fisheries in the Northeast Atlantic by the European Commission in 2007 concluded that many deep sea fish stocks have such low productivity that “sustainable levels of exploitation are probably too low to support an economically viable fishery”.5
Through the years, several organizations have called for additional measures to strengthen the EU’s deep sea fisheries regulation. An intensive campaign was waged by the DSCC and partners from 2012–2016, leading to the adoption of a new EU regulation for the management of deep sea fisheries in EU waters in December 2016. This new regulation entered into force in January 2017, the culmination of four and a half years of campaigning, negotiations and consultation with member states, Parliament, Council and the Commission.
The measures adopted in the 2016 regulation represent a major improvement over the deep sea fisheries regulation in force since 2002. They will go a long way towards meeting the commitments made by the EU at the UNGA and applying them to protect deep sea ecosystems in EU waters, provided that the regulation is implemented effectively. To learn more about the milestones in the walk towards this new EU legislation, please visit the section EU past campaign.