Revillagigedo Archipelago IMMA

Size in Square Kilometres

54 706 km2

Qualifying Species and Criteria

Humpback whale – Megaptera novaeangliae

Criterion A; C (1)

Marine Mammal Diversity 

Criterion D (2)

Balaenoptera edeni, Balaenoptera musculus, Stenella attenuata, Stenella longirostris, Stenella coeruleoalba, Tursiops truncatus, Steno bredanensis, Delphinus delphis, Pseudorca crassidens, Orcinus orca, Ziphius cavirostris, Mesoplodon peruvianus, Physeter macrocephalus

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The Revillagigedo Archipelago is an island chain of volcanic origin 465 km south of the Baja California Peninsula, and 575 km west of mainland Mexico. The archipelago serves as a breeding ground for humpback whales (Megaptera novaeangliae) belonging to the offshore population unit from Mexico. The population’s migratory destinations are to temperate and subarctic feeding grounds in the North Pacific, from Russia to British Columbia. The population size (estimated to be between 780 to 1978 individuals) is similar to the Central America distinct population segment (DPS), which is considered ‘Endangered’ under the US Endangered Species Act. The residency times and inter-annual site fidelity in this area are the highest of the studied population units in Mexico. The Revillagigedo Archipelago IMMA is also regularly used by a richness of 14 species of cetaceans.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

The Revillagigedo Archipelago IMMA serves as an important habitat and breeding ground for humpback whales (Megaptera novaeangliae). This species is considered Least Concern (LC) globally on the IUCN Red List. However, the National Marine Fisheries Service (NMFS) includes the humpback whales from the Revillagigedo Archipelago as part of the Mexico distinct population segment (DPS) with a ‘Threatened’ status (Bettridge et al., 2015). The humpback whales from the Revillagigedo Archipelago population were recognized by González-Peral (2011) as the Mexican offshore population unit and recently by Martien et al. (2021) as the ‘Mex-NPac demographic independent population’. The population size was calculated by Wade et al. (2022) to be between 788 and 1978 individuals based on photographic and genetic mark-recaptures documented between 2004 and 2006 under the auspices of project SPLASH. This is similar in size to the Central America distinct population segment considered ‘Endangered’ under the US Endangered Species Act (Bettridge et al., 2015). These whales migrate from the IMMA to temperate and sub-Arctic feeding grounds from Russia to British Columbia (Urbán et al., 2000; Calambokidis et al., 2008; González-Peral., 2011; Titova et al., 2018, 2019).

Criterion C: Key Lifecycle Areas

Sub-criterion C1: Reproductive Areas

Humpback whales aggregate in the Revillagigedo Archipelago for reproductive behaviours including mating and calving (Jacobsen et al., 2002). According to González-Peral (2011), the male:female ratio within the islands is 2.38 :1. The whales have an average residency of 14.2 days (16.9 d for males; 14.2 d for females; and 17.2 d for mothers with calves). The residency time and the inter-annual site fidelity in the area are higher than in other population units studied in Mexico. According to Martínez-Aguilar (2008), with the greatest concentration of whales is found around the northwest and southwest sides of Socorro Island. Mother-calf pairs have been observed to prefer the south and southwest of the island.

Criterion D: Special Attributes

Sub-criterion D2: Diversity

The convergence of the California and Equatorial currents around the islands generate high levels of productivity, which allow the islands to support a rich biodiversity of marine life ranging from plankton, and small prey species, through to the largest top predators (Fiedler and Lavín, 2017; Hubbs and Roden, 2021). The Revillagigedo Archipelago IMMA is utilised regularly by 14 species of cetacean. Three species of Balanopteridae are regular visitors of this IMMA, the blue whale, the humpback whale and the Bryde´s whale. One Physeteridae specie, the sperm whale; Two Zhipiidae species, the Cuvier´s beaked whale and the pygmy beaked whale; and seven Delphinidae species, the offshore pantropical spotted dolphin (Stenella attenuata attenuata), the eastern spinner dolphin (Stenella longirostris oreintalis), the striped dolphin (Stenella coeruleoalba), the bottlenose dolphin (Tursiops truncatus), the rough toothed dolphin (Steno bredanensis), the false killer whale (Pseudorca crassidens) and the killer whale (Orcinus orca)  (Wade and Gerrodette, 1993; Gerrodette et al., 2008; SEMARNAT, 2019;  Hoyt, 2012).

Supporting Information

Bettridge, S., C.S. Baker, J. Barlow, et al. 2015. Status review of the humpback whale (Megaptera novaeangliae) under the Endangered Species Act. NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-540. 240p.

Calambokidis, J., E.A. Falcone, T.J. Quinn, et al. 2008. SPLASH: Structure of populations, levels of abundance and status of humpback whales in the north Pacific. Cascadia Research. Final report for contract AB133F-03-RP-00078. 57 pp.

Fiedler, P. C., & Lavín, M. F. 2017. Oceanographic conditions of the eastern tropical Pacific. In Coral reefs of the eastern tropical Pacific (pp. 59-83). Springer, Dordrecht.

Gerrodette, T., Waters, G., Perryman, W., Ballance, L. 2008. Estimates of 2006 dolphin abundance in the eastern tropical Pacific, with revised estimates from 1986–2003. NOAA Technical Memorandum NMFS-SWFSC 422: 39 pp.

González-Peral, U. 2011. Definición y características de las unidades poblacionales de las ballenas jorobadas que se congregan en al Pacifico Mexicano. Tesis para Doctor en Ciencias. Universidad Autónoma de Baja California Sur. 92 pages.

Hoyt, E. 2012. Marine protected areas for whales, dolphins and porpoises: A world handbook for cetacean habitat conservation. Routledge.

Hubbs, C. L., & Roden, G. I. 2021. 5. Oceanography and Marine Life along the Pacific Coast. In Handbook of Middle American Indians, Volume 1 (pp. 143-186). University of Texas Press.

Jacobsen, J., Falcone, E. A., Cerchio, S., & Cholewiak, D. 2002. Population characteristics of humpback whales wintering at the Archipelago Revillagigedo, Mexican Pacific, 1996–2001. Seattle, Washington: National Marine Mammal Laboratory.

Martien, K., Taylor, B., Archer, F., Audley, K., Calambokidis, J., Cheeseman, T., De Weerdt, J., Frisch-Jordán, A., Martínez-Loustalot, P., Ortega-Ortiz, C., Patterson, E.M., Ransome, N., Ruvelas, P., & Urbán-Ramírez, J. 2021. Evaluation of Mexican Distinct Population Segment of Humpback Whales as units under the Marine Mammal Protection Act. Technical Memorandum. National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center. US Department of Commerce.

Martínez-Aguilar, S. 2008. Un modelo de abundancia absoluta de la ballena jorobada Megaptera novaeangliae, en aguas adyacentes a las Islas del Archipiélago de Revillagigedo, México. Tesis de Licenciatura. Facultad de Ciencias. UNAM. 83 pp.

Secretaría de Medio Ambiente y Recursos Naturales. 2019. Programa de Manejo Parque Nacional Revillagigedo. Comisión Nacional de Áreas Naturales Protegidas. 350 pp.

Titova, O.V., O.A. Filatova, I.D. Fedutin, et al. 2018. Photo-identification matches of humpback whales (Megaptera novaeangliae) from feeding areas in Russian Far East seas and breeding grounds in the North Pacific. Marine Mammal Science 34(1): 100-112. DOI: 10.1111/mms.12444

Titova, O.V., O.A Filatova, I.D. Fedutin, et al. 2019. Movements of humpback whales (Megaptera novaeangliae) between feeding aggregations in the Far Eastern seas and the migration links with breeding grounds. Marine Mammals of the Holarctic 1: 322-3277. DOI: 10.35267/978-5-9904294-0-6-2019-1-322-328.


Urbán, J., Jaramillo, A., Aguayo, A., Guevara, P.L. and others. 2000. Migratory destinations of humpback whales wintering in the Mexican Pacific. J Cetacean Res Manag 2: 101−110

Wade, P. R., & Gerrodette, T. 1993. Estimates of cetacean abundance and distribution in the eastern tropical Pacific. Report of the International Whaling Commission, 43(477-493).

Wade, P., Quinn, T., Barlow, J., Baker, C. S., Burdin, A., Calambokidis, J., Clapham, P., Falcone, E., Ford, J., Gabriele, C., Leduc, R., Mattila, D., Rojas-Bracho, L., Straley, J., Taylor, B., Urbán-Ramírez, J., Weller, D., Witteveen, B., & Yamaguchi, M. 2022. Revision of estimates of abundance and migratory destination for North Pacific humpback whales in both summer feeding areas and winter mating and calving areas. Scientific Committee Report-International Whaling Commission. SC/68D/IA/03.


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