Seamounts at Risk

Which countries still permit bottom trawl fishing on seamounts and oceanic ridges on the high seas?

There are only a handful of countries that continue to permit bottom trawl fisheries on seamounts and oceanic ridge systems in areas beyond national jurisdiction (see table below). These include New Zealand, Japan, Spain, Cook Islands, Korea and the Faroe Islands. As of 2018, there were approximately 20 vessels fishing on seamounts, with a reported combined catch of approximately 12,000 tonnes. This represents only 0.0142% of the global marine fish catch of 84.4 million tonnes for 2018 estimated by the UN FAO. (1)

Most of the reported bottom trawl catch on seamounts on the high seas in 2018 consisted of four species: pelagic armourhead in the North Pacific; splendid alfonsin/alfonsino in the North Atlantic, North Pacific and Southern Indian Ocean; orange roughy in the Southwest Pacific and Southern Indian Ocean; and roundnose grenadier in the Northeast Atlantic.  The status of the stocks of these four species in these areas has either not been assessed or is unknown; is recognized as depleted (pelagic armourhead in the North Pacific, alfonsino in the Northeast Atlantic); or, in the case of roundnose grenadier in the northeast Atlantic, categorized as “endangered” on the IUCN Red List. (2)


Fishing Nation / Flag State Number of vessels per RFMO / Organisation Total Reported Catch (tonnes)
New Zealand SPRFMO: 5 1,570
Japan NPFC: 4


NPFC: 3,576

SIOFA: 1,758

Cook Islands SIOFA: 2 2,622
Spain NEAFC: 4-6


~1,500-2,000 (6)


Korea NPFC: 1 449
Faroes Islands NEAFC:1 29
Estimated Total Vessels ~20  
Estimated Total Catch   ~12,000

Numbers of vessels reported deep water bottom trawling and/or midwater trawling for deep-sea species on seamounts, oceanic ridge systems (3), and large underwater features (4) on the high seas in 2018 (5)


What will it take to protect all seamounts?


Given that virtually all seamounts surveyed to date have been found to contain vulnerable marine ecosystems (VMEs) and the serious concerns over the impact of bottom trawling on seamounts and other underwater features expressed by scientists as reflected in the UN’s 1st World Ocean Assessment, all seamounts and related features in areas beyond national jurisdiction should be closed to bottom trawl fishing to protect VMEs.


This would go a long way to protecting biodiversity on a global scale, and would make a substantial contribution to the effective implementation of the UNGA resolutions as well meeting SDG 14, Target 14.2 which calls on States to, by 2020, “sustainably manage, and protect marine and coastal ecosystems to avoid significant adverse impacts, including by strengthening their resilience and take action for their restoration”. It would also serve to implement Article 6.3 of the 1995 UN Fish Stocks Agreement which calls for protecting habitats of special concern and Article 194.5 of UNCLOS which calls for protection of rare or fragile ecosystems.



  1. UN FAO State of World Fisheries and Aquaculture 2020.
  2. Nieto et. al., (2015). European Red List of Marine Fishes. International Union for the Conservation of Nature (IUCN)
  3. The Southwest Indian Ocean Ridge and other ridge systems in the Southern Indian Ocean, the Northern Mid Atlantic Ridge and the Louisville Ridge and West Norfolk Ridge in the Southwest Pacific.
  4. Examples of large underwater features where trawling occurs on the high seas include the Lord Howe Rise in the Southwest Pacific/Tasman Sea; Walters Shoal in the Southern Indian Ocean; Hatton Bank in the Northeast Atlantic.
  5. Sources

    NPFC: Annual summary footprint of bottom fisheries in the Convention Area, Document Number: NPFC-2020-AR-Annual Summary Footprint – Bottom Fisheries

    SPRFMO: New Zealand Annual Report. 7th Meeting of the Scientific Committee of SPRFMO, October 2019. SC7-Doc23

    SIOFA: 5th Meeting of the Southern Indian Ocean Fisheries Agreement (SIOFA) Scientific Committee, 30 March – 3 April 2020.  Annual National Report of Japan. SC-05-22.

    4th Meeting of the Southern Indian Ocean Fisheries Agreement (SIOFA) Scientific Committee, 24-29 March 2019. National Report – Cook Islands. SC-04-29.

    NEAFC: Reported Catch 2018. ; Annual Overview of Bottom Fishing in the NEAFC Regulatory Area. 1st January to 31st December 2018. NEAFC Annual Meeting 2019. AM 2019-52. November 2019.

    NAFO: Report of the NAFO Commission and its Subsidiary Bodies (STACTIC and STACFAD). 41st Annual Meeting of NAFO 23-27 September 2019. Annex 45. Annual Fisheries and Compliance Review 2019. & NAFO Scientific Council Reports 2019. Splendid Alfonsin. Page 218.


  1. These are best estimates of the numbers of trawl vessels and catch on the Mid Atlantic Ridge (MAR) deep-sea midwater and Hatton Bank bottom trawl fisheries targeting roundnose grenadier based on information available from NEAFC. A caveat concerns the deep midwater trawl fishery on the MAR where the ridge is believed to be too deep for midwater trawls to contact the bottom. In addition, in the Northeast Atlantic, one vessel from Spain engaged in midwater trawling for splendid alfonsino for 10 days in 2018 on a seamount in the NAFO Regulatory Area. Total catch: 2t. This fishery, the last remaining trawl fishery on seamounts in the NAFO Regulatory Area, was banned in 2019.