1. Key Points

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The Scaly-foot Snail (Chrysomallon squamiferum), a deep-sea snail endemic to deep-sea hydrothermal vents, has been formally listed as an Endangered species in the International Union for Conservation of Nature (IUCN) Red List.

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Japanese research efforts, including those of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), provided materials and scientific knowledge that facilitated the assessment of this Red List assessment.

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This is the first case in the IUCN Red List where deep-seafloor resource development has been taken into consideration, and it clearly indicates the importance of evaluating the effects of anthropogenic impacts on deep-sea organisms.

2．Overview

The International Union for Conservation of Nature (IUCN), a global authority on conservation, issued an update to its renowned IUCN Red List of Threatened Species on July 18^th. The Scaly-foot Snail (Chrysomallon squamiferum; Figure 1), a unique species with iron-infused scales endemic to deep-sea hydrothermal vents of the Indian Ocean, has been newly added to the Red List as Endangered (EN [B2ab (iii)]). Research initiatives that ultimately resulted in this classification were largely led by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), using numerous research vessels and submersibles, in cooperation with other research institutions within and outside Japan, to investigate seafloor hydrothermal activity in the Indian Ocean from the 1990s to date. Chong CHEN, a member of the SUGAR Program, X-STAR, JAMSTEC, contributed his valuable research findings across multiple fields, including the physiology, evolution, and ecology of this species that facilitated complete assessment of this species for the IUCN Red List.

The Scaly-foot Snail is known from only three hydrothermal vents, totaling about two soccer fields in size (Figures 3 and 4). Hydrothermal vents are facing surging interests in seafloor sulfide mining, and two of these three vents (Kairei and Longqi) are currently under mining exploration licenses issued by the International Seabed Authority. The limited number of suitable habitat sites, restricted extent of its specialized habitat, inferred infrequent dispersal interactions among populations, as well as concerns regarding disruption to its habitat by future seafloor resource development, have all contributed to the evaluation of the Scaly-foot Snail as Endangered (EN [B2ab (iii)]).

This new addition to the Red List serves as an important case study, showing how the IUCN Red List can be applied to species inhabiting deep-sea habitats that remain largely unexplored when sufficient information is gathered, and how the IUCN Red List can be used as a key tool in deep sea conservation. An article highlighting this new development in deep-sea biodiversity conservation was published in Nature Ecology & Evolution on July 23^rd, 2019 (JST).

Title: Red Listing can protect deep-sea biodiversity
Authors: Julia D. SIGWART¹、Chong CHEN^2*、Elin A. THOMAS¹、A. Louise ALLCOCK³、Monika BÖHM⁴、Mary SEDDON⁵
1. Queen’s University Belfast, Marine Laboratory　2. X-STAR, JAMSTEC 3. National University of Ireland, Galway　4. Zoological Society of London　5. IUCN SSC Mollusc Specialist Group