In the Davis Strait between Greenland and Canada’s Baffin Island, where only the faintest rays of sunlight penetrate, swim strange-looking flat fish with both eyes on the right side of their heads. These are Greenland halibut (Reinhardtius hippoglossoides), which industrial bottom trawlers have fished here for decades.
To get the halibut in Greenlandic waters, the trawlers operate at least 3 nautical miles (5.6 kilometers) from the coastline and drag cone-shaped nets across the seabed. These nets hauled up approximately 12,400 metric tons of halibut in 2021 alone within Greenland’s waters, but they also overturn rocks and sediment in the process. (Fisheries closer to shore catch more halibut annually, but their method — a fishing line carrying up to 2,500 baited hooks, or longline — is much less destructive to the seabed.) The halibut, along with cod, mackerel, crab and prawn, is the mainspring of the Greenlandic fishing industry.
Bottom trawling takes a toll: it crushes slow-growing deep-sea organisms, some of them millennia old, that are irreplaceable on human timescales. Now, the discovery of potential vulnerable marine ecosystems (VMEs) on the Davis Strait seafloor has shown what, specifically, is at stake off Greenland’s coast. A 2020 paper identified a soft coral garden spanning 486 square kilometers (188 square miles) just outside one of the main halibut fishing grounds. And a paper published in September 2021 describes a field of sea pens, quill-like animals closely related to jellyfish; meadows of cup corals; and mixed assemblages of corals, sponges and sea pens, some located where trawlers fish, that the authors say are possible VMEs as well. The U.N. says countries should protect VMEs, and the discovery is prompting Greenland and its fishers to change their practices. But details are sparse and experts question whether the measures are sufficient.
