Main Hawaiian Islands IMMA

Area Size

6 396 km2

Qualifying Species and Criteria

Hawaiian monk seals – Neomonachus schauinslandi

Criterion A; C (1)

Marine Mammal Diversity

Stenella longirostris, Tursiops truncatus, Feresa attenuata, Globicephala macrorhynchus, Kogia sima, Mesoplodon densirostris, Peponocephala electra, Stenella attenuata, Steno bredanensis, Ziphius cavirostris, Pseudorca crassidens, Megaptera novaeangliae

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The Main Hawaiin Islands IMMA holds a significant proportion of the global population of the Endangered Hawaiian monk seal (Neomonachus schauinslandi). It encompasses 6 discrete areas of critical habitat designated for the Hawaiian monk seal in the Main Hawaiian Islands (MHI) under the U.S. Endangered Species Act. These areas include preferred pupping and nursing areas, significant haul-out areas, and/or marine foraging areas that are essential for the persistence of the species.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

The Hawaiian monk seal is listed as Endangered (EN C1) on the IUCN Red List of Threatened Species (Littnan et al. 2015). According to the current IUCN Red List account, within the Monk Seal’s range, two regions are often distinguished: the Northwestern Hawaiian Islands, comprising eight subpopulations located on remote atolls and small islands, and the Main Hawaiian Islands, comprising eight large high islands and associated small islets. Seals in the Main Hawaiian Islands are a single subpopulation. The Main Hawaiian Islands IMMA includes specifically the Main Hawaiian Island subpopulation of Hawaiian monk seal.

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

The area provides critically important breeding habitats for the Endangered Hawaiian monk seal, which includes areas for pupping (Littnan et al. 2015).

Supporting Information

50 CFR 226. 2015. Endangered and Threatened Species: Final Rulemaking To Revise Critical Habitat for Hawaiian Monk Seals, pp: 50925-50988

Baker, J. D. and Johanos, T. C. 2004. Abundance of the Hawaiian monk seal in the main Hawaiian Islands. Biological Conservation 116: 103-110.

Littnan, C., Harting, A. and Baker, J. 2015. Neomonachus schauinslandi. The IUCN Red List of Threatened Species 2015: e.T13654A45227978. Downloaded on 28 March 2017.

National Marine Fisheries Service. 2014. Revision of Critical Habitat for Hawaiian Monk Seals. Final Biological Report. Honolulu, HI, USA. Available at:

National Marine Fisheries Service. 2007. Recovery Plan for the Hawaiian Monk Seal. Honolulu, HI, USA. Available at:


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