Abalones at risk: A global Red List assessment of Haliotis in a changing climate

above), and data of both species are therefore confused. Because H. madaka has been severely overfished for many years, it is now extremely scarce in the overall abalone catch in Japan, with research determining that in one area, landed values decreased year on year, with no spec- imens landed after 2009 [78]. It has also suffered the consequence of anti-fouling chemicals used on vessel hulls [79]. The collapse in combined stocks of H. discus, H. madaka and H. gigantea, although inseparable by species, would indicate that one or more may have already passed the threshold for Critically Endangered, and all would benefit from comprehensive empirical evidence. Although H. supertexta is considered by WoRMS and Geiger & Owen (2012) to be a separate species [34], Hsu & Gwo (2017) using molecular markers determined it to be the subspecies, H. diversicolor supertexta [80]. Owing to this long-standing taxonomic confusion, H. diversicolor has been categorised as DD. All other species in this sector are of LC. Table 5. Abalone species of Indo-West-Pacific. Species Size C Distribution Cat mm Indo-West-Pacific H. asinina 120 C Andamans, Japan, Malaysia, Indonesia, S. China, Viet Nam, Philippines, Australia, Fiji LC H. clathrata 46 E. Africa, entire Indo-West-Pacific incl. Japan, Australia, and E. to Tonga. LC H. discus 232 C Japan and Korea EN H. dissona 36 Australia (Queensland), Fiji, Guam, New Caledonia, N. Mariana Is, Tonga LC H. diversicolor 109 C Southern Japan, China, and across much of Southeast Asia to northern Australia DD

H. fatui 75 Indonesia (Papua), N. Mariana Is, Philippines, Solomon Is, Tonga DD H. gigantea 233 C Japan and Korea EN H. glabra 68 Japan, Malaysia, Indonesia, Philippines, N. Australia LC H. jacnensis 30 Japan, Philippines, Indonesia, New Caledonia, Micronesia, Tonga, Am. Samoa, Nieu LC H. madaka 245 C Japan and Korea EN H. ovina 92 C Maldives to Society Is.; SW Japan to Queensland and Western Australia LC H. papulata 27 Sri Lanka, Philippines, Thailand, Papua New Guinea, N. Australia LC H. planata 50 Sri Lanka to Fiji and from Japan to N. of W. Australia LC H. pulcherrima 45 French Polynesia incl. Tuamotus, Society Is, Gambier Is, and Marquesas; Pitcairn Is DD H. varia 86 Sri Lanka to Tonga and from Japan to Australia LC ‘C’ denotes commercially fished. https://doi.org/10.1371/journal.pone.0309384.t005 Fig 6. H. discus hannai (EN). Occurs in Japan & Korea. The world’s most consumed abalone. Reprinted under a CC BY license with permission from Buzz Owen, original copyright. https://doi.org/10.1371/journal.pone.0309384.g006 PLOS ONE Abalones at risk: A global Red List assessment of Haliotis PLOS ONE | https://doi.org/10.1371/journal.pone.0309384 December 23, 2024 14 / 25