Babuyan Marine Corridor IMMA

Size in Square Kilometres

16 893 km2

Qualifying Species and Criteria

Humpback whale – Megaptera novaeangliae

Criterion A; C (1)

Rough-toothed dolphin – Steno bredanensis

Criterion B (1); C (2)

Marine Mammal Diversity 

Criterion D (2)

Physeter macrocephalus, Globicephala macrorhynchus, Pseudorca crassidens,
Feresa attenuata, Peponocephala electra, Kogia sima, Stenella attenuata, Stenella longirostris, Tursiops truncatus, Grampus griseus, Lagenodelphis hosei, Steno bredanensis, Megaptera novaeangliae

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The waters around the Babuyan Islands, northern Luzon, in the Philippines serve as the only known wintering/breeding ground of humpback whales (Megaptera novaeangliae) in the Philippines. These whales are part of the Western North Pacific Distinct Population Segment (DPS), one of only four DPSs to be  listed as Endangered under the U.S. Endangered Species Act, when most others were delisted in 2016. A photo identification catalogue of 230 individual whales reveals that the proportion resighted annually is 42.61%. A within-region return index of 3.41 may indicate a small population utiilising this breeding ground with a high rate of return (Acebes et al. 2021). Group composition and behaviour observed during sightings confirm the area’s importance for mating, calving and nursing. The IMMA also hosts a small resident population of rough-toothed dolphins (Steno bredanensis), which are rarely observed  in the Philippines but are one of the most commonly encountered species in the Babuyan Marine Corridor. Furthermore, this IMMA which is also a marine Key Biodiversity Area (KBA), is home to 11 other species of cetaceans as well as whale sharks, sea turtles and numerous species of fish and corals.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

Humpback whales which winter and breed within this area are a part of the western North Pacific Distinct Population Segment (DPS), which is listed as Endangered under U.S. Federal Status (U.S. Federal Register, 2016). Based on the review of the National Marine Fisheries Service, who upon reconsideration of the information available at that time has classified the extinction risk to the Western North Pacific DPS as high, not moderate, this DPS was listed as Endangered instead of Threatened (U.S. Federal Register, 2016). There is only one breeding area for humpback whales in the Philippines and due to a restricted area of occupancy and the level of threats present in that particular site, the locally occurring population of the species was listed as Vulnerable in the National Red List of the Philippines (Alava et al. 2012).

Criterion B: Distribution and Abundance

Sub-criterion B1: Small and Resident Populations 

Based on a preliminary photo-identification study of Steno bredanensis there are 56 individuals around the Camiguin Norte Island in the Babuyan Marine Corridor (Nakagun et al. 2013). Group size estimates varied from 5-50 individuals although the largest group size based on photo-identification was 17 individuals (Ibid.). Re-sights of individuals between and within seasons also suggests residency within the area.

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

This is the only known winter/breeding area for humpback whales in the Philippines (Acebes et al. 2007). Humpback whales are seen in social groups common to breeding/wintering grounds including cow-calf pairs, cow-calf-escort groups, singers and surface-active groups.

Criterion D: Special Attributes

Sub-criterion D2: Diversity

This marine key biodiversity area is home to 12 other species of regularly occurring cetacean species and includes sperm whales (Physeter macrocephalus), short-finned pilot whales (Globicephala macrorhynchus), false killer whales (Pseudorca crassidens), pygmy killer whale (Feresa attenuata), melon-headed whale (Peponocephala electra), pantropical spotted dolphin (Stenella attenuata), spinner dolphin (Stenella longirostris), common bottlenose dolphin (Tursiops truncatus), dwarf sperm whale (Kogia sima), Risso’s dolphin (Grampus griseus), and Fraser’s dolphin (Lagenodelphis hosei) (Acebes and Lesaca 2003, Acebes et al. 2013).

Supporting Information

Acebes, J.M.V. and Lesaca, L.A.R. 2003. Research and conservation of humpback whales (Megaptera novaeangliae) and other cetacean species in the Babuyan Islands, Cagayan Province, Northern Luzon, Philippines.  In:  Proceedings of the Regional conference on Environment and Development, The Sierra Madre Mountain Range:  Global Relevance, Local realities, Cabagan, Isabela, Philippines.  Cagayan Valley program on environment and development, Golden Press, Tuguegarao City.

Acebes, J.M.V., Darling, D.J. and Yamaguchi, M. 2007. ‘Status and distribution of humpback whales (Megaptera novaeangliae) in northern Luzon, Philippines.’ J. Cetacean Res. Manage. 9(1): 37–43.

Acebes, J.M.V. 2013. ‘Small cetacean diversity in the Babuyan Islands, Northern Luzon, Philippines’, poster presented at the 20th Biennial Conference on the Biology of Marine Mammals, Dunedin, New Zealand, 9-13 December 2013.

Acebes, J.M.V. 2021. ‘Interchange and movements of humpback whales (Megaptera novaeangliae) between western North Pacific winter breeding
grounds in northern Luzon, Philippines and Okinawa, Japan.’ Journal of Cetacean Research and Management, 22 (1): 39-53.

Alava, M.N.R., Dolar M.L.L., Sabater, E.R., Aquino, M.T.R., Santos, M.D. (eds.). 2012. Red List Status of Marine Mammals in the Philippines. Bureau of Fisheries and Aquatic Resources – National Fisheries Research and Development Institute. 194 pages.

Calambokidis, J., Falcone, E.A., Quinn, T.J., Burdin, A.M., Clapham, P.J., Ford, J.K.B., Gabriele, C.M., LeDuc, R., Mattila, D., Rojas-Bracho, L., Straley, J.M., Taylor, B.L., Urban R, J., Weller, D., Witteveen, B.H., Yamaguchi, M., Bendlin, A., Camacho, D., Flynn, K., Havron, A., Huggins, J. and Maloney, N. 2008. SPLASH: Structure of populations, levels of abundance and status of humpback whales in the North Pacific. Final report for Contract AB133F-03-RP-00078, US Department of Commerce Western Administrative Center, Seattle, Washington. 

Hill, M.C., Bradford, A.L., Steel, D., Baker, C.S., Ligon, A.D., U, A.C., Acebes, J.M.V., Filatova, O.A., Hakala S., Kobayashi, N., Marimoto, Y., Okabe, H., Okamoto, R., Rivers, J., Sato, T., Titova, O.V., Uyeyama, R.K., Oleson, E.M. 2020. ‘Found: A Missing breeding grounds for endangered western North Pacific humpback whales in the Mariana Archipelago.’ Endangered Species Research, 41: 91-103.

Nakagun, S., Acebes, J.M.V. and Ponzo, A. 2013. ‘Steno bredanensis in the Babuyan Islands, Northern Luzon, Philippines’, poster presented at the 20th Biennial Conference on the Biology of Marine Mammals, Dunedin, New Zealand, 9-13 December 2013.

Okabe, H., Acebes, J.M.V, Kobayashi N., Nakagun S., Higashi N., and Uchida S. 2017. ‘To go or not to go: Movements of Humpback whales between breeding grounds in Okinawa, Japan and the Philippines’, poster presented at the 22nd Biennial Conference on the Biology of Marine Mammals, Halifax, Canada, 22-27 October 2017.

Silberg, J. N., Acebes, J.M.V., Burdin, A.M., Mamaev, E.G., Dolan, K.C., Layusa, C.A. and   Aca, E.Q. 2013. ‘New insight into migration patterns of western North Pacific humpback whales between the Babuyan Islands, Philippines and the Commander Islands, Russia.’ Journal of Cetacean Research and Management 13:53–57.

Titova, O.V., Filatova, O.A., Fedutin, I.D., Ovsyanikova, E.N., Okabe, H., Kobayashi, N., Acebes, J.M.V., Burdin, A.M., Hoyt, E. 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.

United States of America Federal Register. 2016. U.S. Federal Register Accessed on October 28th 2018

Yamaguchi, M., Acebes, J.M.V. and Miyamura, Y. 2002. The breeding ground distribution of the humpback whales, Megaptera novaeangliae, in the western North Pacific and their transmovements among the Ogasawara Islands, the Ryukyu Islands and the Philippines. Paper presented at the Second Conference on Marine Mammals of Southeast Asia, Dumaguete, Philippines, July 2002 (unpublished)


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