Vulnerable ecosystems discovered near deep-sea trawl fishery

Leading conservation charity ZSL provides vital new evidence to inform sustainable marine management in the region 

Vulnerable deep-sea species and habitats have been identified for the first time in the Davis Strait, west Greenland, near areas currently subject to extensive trawling for halibut. 

Trawling creates significant impact on the sea floor, destroying or degrading precious marine habitats. The discovery of deep-sea vulnerable marine ecosystems such as 'fields' of sea-pens (Halipteris finmarchica), along with other coral and sponge habitats in this area, is cause for concern, according to experts from ZSL (Zoological Society London), University College London (UCL), and the Greenland Institute of Natural Resources (GINR) in a paper published today (Wednesday 8 September 2021) in the ICES Journal of Marine Science

The fishing industry is an important livelihood for many people in Greenland and forms a sizable part of the country’s economy. However, offshore halibut fishing employs heavy trawling gear to catch this deep-sea fish, which can have a devastating impact on the seabed. Weighing over 10 tonnes, the gear is towed along the seafloor for several hours at a time at depths of up to 1,400 m.

northern lights

Using a low-cost video sled placed on the seabed, the team were able to explore previously unseen ecosystems, and document key species of coral and sponge in the region. The intention is for their findings to inform sustainable fishery management, to ensure vulnerable species and habitats are protected from the impacts of trawling. 

PhD Researcher at ZSL’s Institute of Zoology (IoZ) and lead author on the study, Stephen Long said: “Our analysis provides evidence that there is a negative relationship between trawling and the abundance of some key species, and that the composition of deep-sea marine species communities is being affected by trawling.  Of particular concern are potential vulnerable marine ecosystems that may be at risk of serious or irreversible harm from trawling. It has been invaluable to work so closely with partners in Greenland to investigate these previously unexplored deep seas.

animals on the seabed

 “This work is about recognising the impacts of trawling and providing new information to decision-makers to support evidenced-based management, ensuring fisheries are sustainable, whilst vulnerable ecosystems are protected – it’s about putting nature at the heart of these decisions.”  

Both the fishing industry leaders and Greenlandic government are keen to ensure the sustainability of this key sector. In recent years the offshore halibut fishery and other fisheries have sought and obtained the MSC (Marine Stewardship Council) sustainability certification. Stephen continued: “A key test for industry, government and the MSC certification will be how fishery management responds to new scientific information about these poorly known deep-sea regions.”  

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Kristina Guldbæk is Project Manager at Sustainable Fisheries Greenland (SFG) who represent the Greenlandic fishing industry for the purposes of MSC (Marine Stewardship Council) certification. 

Kristina Guldbæk said: “The work that ZSL has carried out when it comes to investigating the Greenland seabed has played a central role in the MSC-certification of Greenlandic fisheries. Before the cooperation or partnership between ZSL and Sustainable Fisheries Greenland was initiated more than a decade ago, the knowledge regarding habitats and vulnerable areas in Greenlandic waters was very limited. But we now have the knowledge to protect some of the most sensitive areas and organisms, so that sea pens and soft-coral gardens will still be there for us to witness in the future.”

Research Fellow at ZSL’s Institute of Zoology and co-author on the study, Chris Yesson has just returned from an expedition exploring deep-sea regions around Greenland. He said: “Deep-seas - waters deeper than 200m - account for more than 99% of the global ocean volume and cover 65% of the planet’s surface. They are considered the largest and least explored biome on earth.  

This documentation and evidence gathering is a vital piece of the puzzle for effective management of these cold, dark and undiscovered places." 

Chris Yesson on board a research vessel with icebergs in the background.

Last year experts from ZSL, UCL and GINR described a ‘soft coral garden’, vulnerable marine ecosystem (VME) which was the first of its kind to be identified in Greenlandic waters. Previously, ZSL's research (in collaboration with GINR) has also led to the closure of around 1,900 km2 of seabed in Melville Bay, northwest Greenland. The new study forms part of ongoing work with Greenland fisheries to document habitats, identify potential vulnerable marine ecosystems, and support decision making on creating more  protected areas.  

 ZSL is urging world governments and policy makers to put nature at the heart of all decision making to truly tackle the global threats of climate change and biodiversity loss, and will be calling on leaders to make this commitment at COP26 in Glasgow in November. You can support ZSL's world-leading conservation work by donating to us online:

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