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Featured image: An orange basket star covers a Picasso sponge at Davidson Seamount, California. Image courtesy of NOAA and MBARI.

The deep sea harbors the greatest number of species and ecosystems on Earth. Within this vast realm, the dazzling submerged volcanoes called seamounts are among the most diverse places of all. Scientists have long recognized that seamounts are biodiversity hotspots, and science-based arguments from groups like Marine Conservation Institute have helped the United Nations acknowledge this diversity and develop regulations to protect these vulnerable marine ecosystems. We have yet to achieve our ultimate goal – a complete ban on destructive fishing methods like bottom trawling. Since the United Nations 2006 resolution however, a number of successes have been achieved and we are still fighting to better protect seamounts around the world.  

The pandemic has shown our vulnerability and highlights the fragility of life on Earth. The ocean is the planet’s largest ecosystem, vital to Earth’s—and humanity’s—health. Biological diversity remains the cornerstone to healthy functioning ecosystems, and so it seems at once absurd and tragic that destructive fishing continues to destroy seamount habitats. What are we destroying seamount habitats for? Surprisingly, it amounts to a global hunt for basically four species of fish, by just a few nations which often need to subsidize these fisheries to make them profitable. These fish are orange roughy, alfonsino, pelagic armourhead, and roundnose grenadier, most of which are fished via bottom-trawling, which is especially devastating to seamount ecology (responsible for as much as 95% of seamount damage). Landings of these four species result in far less than 1% of global catch according to a report by the Deep Sea Conservation Coalition (2020). In other words, less than one percent of global fishing is responsible for a stunning majority of global ecological damage to seamounts. Six countries are largely responsible for this damage, as seamounts are spread across on the high seas, the 50% of the planet that belongs to all of us! The countries that continue this onslaught are New Zealand, Spain, Japan, Korea, the Faroe Islands and the Cook Islands (DSCC Report 2020). 

Hydrocorals and squarespot rockfish at Tanner Bank. Image courtesy of NOAA.

The good news is that in the 16 years since the passage of U.N. resolution 61/105 there have been growing awareness and protections for increasing numbers of seamounts. Many vulnerable areas have been identified by Regional Fishery Management Organizations (RFMOs), the international bodies that can restrict fishing. One RFMO, the North Atlantic Fisheries Organization, has closed all seamounts to trawling, and under the Convention for the Conservation of Antarctic Marine Living Resources has banned bottom trawling in the convention area. But relatively few marine protected areas have been established in areas beyond national jurisdictions. In large part this is due to the fragmented nature of ocean governance on the high seas. The High Seas Alliance, of which Marine Conservation Institute is a member, is hard at work addressing this significant gap through a new treaty to protect biodiversity beyond national jurisdictions.

There are several seamount protection efforts underway and areas such as the Salas y Gómez and Nazca Ridges off the Pacific Coast of South America and Walvis Ridge off the Atlantic coast of Africa are receiving international attention for added protections. Recognizing these seamount chains and creating the scientific case for strong protections is critical to protecting the wealth of biodiversity that exists in these remote places, and researchers are planning expeditions to gather more information about these places in coming years.

Seamount protection is more than just about remote realms of the High Seas. In U.S. waters seamount protections have occurred through establishment of MPAs as well as restrictions on bottom trawling. The Marine National Monuments established to protect U.S. central Pacific islands have as a significant side benefit protected large numbers of seamounts. Our calculations of seamount protections in these monuments is:

  • Marianas: 17 seamounts (0.17% of global seamounts)
  • Pacific Remote Islands: 141 seamounts (1.4% of global seamounts)
  • Papahānaumokuākea: 106 seamounts (1.0% of global seamounts)
  • Rose Atoll: 3 seamounts (0.03% of global seamounts)

All together these highly protected Marine National Monuments protect 257 seamounts (2.5% of global total)[1].

Close-up of a sea pen colony at 2023 meters depth on Retriever Seamount. Sea pens are octocorals and the characteristic eight pinnate tentacles are plainly visible in this image. The dark line running down below the tentacles of each polyp is the pharynx, connecting the mouth to the bag-like digestive cavity. A mysid shrimp (“possum shrimp”) is swimming by the colony.

Along the west coast partial measures have addressed seafloor impacts from fishing gear through essential fish habitat designation, but the waters above remain unprotected. Marine Conservation Institute in partner with other organizations in the California Seamounts Coalition has been advocating protection of underwater features such as the Mendocino Ridge off Northern California and the water column above. This range is a physically impressive upheaval in the Earth’s crust jutting westward from where the Pacific, North America and Gorda tectonic plates collide.  It supports creatures as diverse as brooding deep-sea octopuses and deep diving sperm whales. The seamounts of Mendocino Ridge hold an iconic place among environmentalists as this is the site where anti-whaling demonstrators in tiny inflatables successfully challenged the industrialized Soviet whalers of the 1970s during the “save the whales” battles. The rich and productive waters above seamounts provide an oasis in the ocean for whales, sharks and tunas. Today’s efforts focus not just on iconic species but the entire ecosystem, and there is growing support and protection to protect seamounts within their marine waters.

The U.S. is notably protecting some seamounts, but gaps remain in the effectiveness of management:

  • Northeast Seamounts and Canyons were designated by President Obama with a plan to phase out commercial fishing. The Trump administration reversed this protection. Advocates have fought back and are challenging this weakening of conservation for the marine national monument, the only one in Atlantic waters of the U.S. You can join the campaign for the Northeast Canyons and Seamounts (USA).
  • California Seamount Campaign is an active effort by over a dozen organizations to expand protections to the water column and make them permanent. The 60 plus seamounts in the federally managed waters off the California coast remain at risk.  Maine Conservation Institute alongside Mission Blue produced 10 short seamount videos during the last year to help educate the public and showcase these underwater treasures – https://www.instagram.com/savingoceans/channel/. The final video in the series was released this week. Enjoy and share widely!
sponges and rockfish at Mendocino Ridge. Image courtesy of NOAA.

You can join seamount protection efforts and use your voice to support conservation:

Use your social media to help these campaigns and share this with your friends!

There is an urgent need to expand protections and the time is now to protect all seamounts from destructive bottom trawling and at least 30% of the ocean beyond these seamount ecosystems.   

For more information –

Deep Sea Conservation Coalition

High Seas Alliance

California Seamounts Coalition


[1] Calculations by Dr. Sam Georgian, Marine Conservation Institute based on data from Harris et al. 2014 (10,234 seamounts and guyots globally).