Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge

Abstract

The Mohn's Treasure, described as an inactive sulfide mound, was discovered at 2,600m depth on the Arctic Mid-Ocean Ridge (AMOR) in 2002. In 2015, we conducted the first biological survey of Mohn's Treasure using remotely operated vehicle (ROV) photo transects and sampling. This site is covered by a thick layer of fine sediments, where hard substratum is only visible as rocky outcrops on ridges. The observed benthic community was typical of Arctic bathyal systems. A total of 46 species (identified as morphospecies) were recorded, with densities varying from 12.2 to 31.6 ind.m −2. The two most abundant phyla were Porifera and Echinodermata. The sediment is dominated by fields of the stalked crinoid Bathycrinus carpenterii, whereas areas of hard substratum were characterized by high abundances of several sponge species and associated fauna. Interest in commercial exploration and exploitation of minerals from massive sulfide deposits is rising globally, and the AMOR is being targeted for mineral exploration within Norwegian waters. Gathering baseline ecological data from these poorly known sites is thus urgent and essential if robust resource management measures are to be developed and implemented. The results of this ecological survey are discussed in relation to the designation of deep-sea vulnerable marine ecosystems (VMEs) and their implication in management and conservation of areas targeted by the emerging deep-sea mining industry.

Habitat variability and faunal zonation at the Ægir Ridge, a canyon-like structure in the deep Norwegian Sea

“…, C. arcticus ) and their associates adapted to comparatively colder Arctic water; and shallower areas with a more diverse megafauna likely benefiting from a dynamic mixing between water masses supplying oxygen and nutrients, as well as preventing high sedimentation. The findings in the ARS are supported by previous observations from neighboring ridges and straits ( Meyer et al, 2016 ; Roberts et al, 2018 ; Meyer et al, 2019 ; Ramirez-Llodra et al, 2020 ).…”

“…The sponge aggregations observed during our study of the ARS are similar to the ones found on the Schulz Bank located on the transition between the Mohn and Knipovich ridges ( Roberts et al, 2018 ; Meyer et al, 2019 ) as well as on the Mohn’s Ridge ( Ramirez-Llodra et al, 2020 ), and, to some extent, in the eastern Fram Strait ( Meyer et al, 2016 ). These Arctic deep-sea habitats are known to have particular ecological significance, playing key roles both in the recycling of major nutrients ( Rooks et al, 2020 ), and serving as refuge and nursery areas for several demersal fish species such as the Arctic skate ( Amblyraja hyperborean [Collett, 1879]), the Roughhead grenadier ( Macrourus berglax Lacepède, 1801) and the Greenland halibut ( Reinhardtius hippoglossoides [Walbaum, 1792]) ( Meyer et al, 2019 ).…”

Meeting sustainable development goals via robotics and autonomous systems

“…RAS could also help those in remote areas to access basic services, with examples ranging from how “ early childhood remote diagnosis and consultation may reduce mortality” to delivering medical supplies, blood or vaccines 38 , or improving education 30 . Furthermore, RAS could facilitate environmental conservation and research in inaccessible locations 39 . Even in seemingly accessible locations such as cities, participants thought that RAS could manage features that are otherwise expensive, dangerous or difficult for humans to access, such as vertical farms 40 or green walls/roofs.…”

“…The negative impact of unmanned aerial vehicles on birds is well-documented 54 . Participants envisaged scenarios where large-scale RAS-deployment would intensify such disruptions and cause comparable issues with other taxonomic groups, including some that are currently poorly known or isolated due to their inaccessible habitats, such as deep-sea organisms 39 .…”

“…Trade-offs emerging from RAS deployment were also identified within goals. For instance, the opportunity to enhance access and monitoring was perceived by participants to be as likely to open new routes for over-exploitation as to improve conservation efforts 39 . Some of the trade-offs that were identified are inherent within the SDGs themselves, such as how SDG12, which promotes consumption and production, could lead to trade-offs with SDGs associated with health, poverty reduction and reduced inequalities 2 .…”