Arabian Sea Humpback Whales

Background and threats

Arabian Sea Humpback whale breaching off the coast of Oman. Photo credit: Daryl McDonald

Historical whaling records and sixteen years of research conducted off the coast of Oman have revealed that Arabian Sea humpback whales are the only non-migratory population of humpback whales in the world. This unique population is endangered (Minton et al., 2008) and genetically isolated (Pomilla et al., 2014) and it may be found to represent a new subspecies. In the 1960’s at least 242 humpback whales were killed by illegal Soviet whaling activity off the coasts of Oman, Pakistan and India (Mikhalev, 1997).  Photo identification studies indicate that fewer than 100 individuals remain in the coastal waters of Oman (Minton et al., 2011). Photo identification, satellite tracking, and acoustic studies indicate a high degree of site fidelity and the occurrence of  behaviour associated with both feeding and reproduction in two main study areas in Oman (Minton et al., 2011, IWC, 2016).  However, little is known about present-day range or numbers in other parts of the Arabian Sea.

Threats throughout the region include:

  • Entanglement in fishing gear: Fishing fleets, particularly those using drift or fixed gillnets, one of the gears most often associated with humpback whale entanglements elsewhere (Johnson et al., 2005), are expanding throughout the Central, Western and Northern Indian Ocean (FAO, 2016). Gillnets, some as long as 26km in length, now account for over 40% of all tuna landings in the region, and although observer coverage for fisheries in the Arabian Sea is extremely limited, bycatch is thought to be responsible for as many as 60,000 cetacean deaths per year in the Central, Western and Northern Indian Ocean (Anderson, 2014). Credible estimates of the number of humpback whales entangled each year are unavailable, but 30—40% of the individuals photo-identified off Oman have entanglement wounds and scars Minton et al., 2011.

    An Arabian Sea Humpback whale in Oman entirely entangled in a fishing net. Photo credit: Robert Baldwin

  • Shipping, including ship strikes and disturbance from vessel noise: The region includes some of the world’s busiest shipping lanes, and new fast-ferry links are being established throughout the region. Port construction and expansion is occurring in key humpback whale habitat off Oman and Pakistan, and coastal development presents many new threats in a region where human populations are growing and infrastructure is expanding.
  • Oil and gas exploration and production carry threats of disturbance from seismic surveys and from construction and drilling noise, associated vessel traffic, and the potential for oil leaks and spills.

Throughout the region, stakeholder awareness of the conservation status of Arabian Sea humpback whales and the many threats they face is low. In the absence of efforts to mitigate the threats, the Arabian Sea humpback whale population is considered at risk of extinction. The  IUCN (Minton et al., 2008),  the IWC (IWC, 2016), and the United States Endangered Species Act recognise the Arabian Sea population as one of only four humpback whale populations in the world still considered to be endangered (NOAA, 2016).

Regional Collaboration for Conservation and Research

A workshop held in January 2015 addressed these pressing conservation concerns and led to the formation of the Arabian Sea Whale Network (ASWN – arabianseawhalenetwork.org), a group seeking to conserve humpback whales and other cetaceans in the Arabian Sea.  ASWN members include academic and independent scientists as well as representatives of large international NGO’s like World Wildlife Fund (WWF) and Wildlife Conservation Society (WCS), IGO’s like the International Whaling Commission (IWC) and grass-roots environmental organizations like the Environment Society of Oman and Plan4theland in Iran. Several CSG members have been involved from the start.

Initiatives involving network members include:

  • Logo of the Arabian Sea Whale Network

    Collaboration with Flukebook.org to develop an online regional data platform that will allow standardization and regional analysis of humpback whale distribution and photo-identification data.

  • Members in Oman, including the Environment Society of Oman and Five Oceans Environmental Services are implementing photo-identification, genetic, acoustic, and satellite tagging studies of humpback whales (IWC, 2016), and using results to inform mitigation strategies and engage the public in whale conservation. They are working with government and industry stakeholders to address the risk of ship strike and to ensure that offshore seismic surveys adhere to measures to minimize disturbance to whales.
  • Members in India, Iran, Oman and Pakistan are engaged in community outreach and education programmes to collect data from fishermen, form effective stranding networks, free live-stranded animals and acquire data and biological samples from stranded whales all over the country.
  • The development of an infographic to raise awareness of Arabian Sea humpback whale throughout the region.

Researchers studying Arabian Sea humpback whales off the coast of Oman. Photo Credit: Daryl McDonald

ASWN members are hoping to foster more regional collaborative acoustic, vessel and genetic studies, capacity building, and inter-governmental collaboration on management and mitigation of the main threats facing Arabian Sea humpback whales.  While the challenges facing those working with this population are daunting, the support and involvement of a global network of whale science and conservation experts associated with IUCN, the International Whaling Commission (IWC) and the Convention for Migratory Species (CMS) is encouraging.

The above provides a background to the Arabian Sea humpback whale population and its conservation. The CSG posts news items and updates about this population, and these can be found on our News page or at the following links:

March 3rd, 2017: New infographic from the Arabian Sea Whale Network

September, 2016:  Arabian Sea humpback whales are one of only four populations still considered Endangered under the United States revised Endangered Species Act listing.

April, 2015: Conservation of the Arabian Sea humpback whale

References

Anderson, R. C., 2014: Cetaceans and tuna fisheries in the Western and Central Indian Ocean. International Pole and Line Federation Technical Report, 2, 133.

FAO, 2016: State of the World’s Fisheries and Aquaculture 2016: Contributing  to Food security and nutrition for all. Food and Agriculture Organization of the United Nations, Rome.

IWC, 2016: Report of the Scientific Committee of the International Whaling Commission 2016:  Annex H:  Report of the Sub-Committee on Other Southern Hemisphere Whale Stocks. International Whaling Commission, Bled, Slovenia.

Johnson, A., G. Salvador, J. Kenney, J. Robbins, S. Kraus, S. Landry and P. Clapham, 2005: Fishigng gear involved in entanglements of right and humbpack whales. Marine Mammal Science, 21, 635-645.

Mikhalev, Y. A., 1997: Humpback whales Megaptera novaeangliae in the Arabian Sea. Marine Ecology Progress Series, 149, 13-21.

Minton, G., T. J. Q. Collins, K. P. Findlay, P. J. Ersts, H. C. Rosenbaum, P. Berggren and R. M. Baldwin, 2011: Seasonal distribution, abundance, habitat use and population identity of humpback whales in Oman. Journal of Cetacean Research and Management, Special Issue on Southern Hemisphere Humpback Whales, 185–198.

Minton, G., T. J. Q. Collins, C. Pomilla, K. P. Findlay, H. C. Rosenbaum, R. Baldwin and R. L. Brownell Jr, 2008: Megaptera novaeangliae, Araiban Sea subpopulation. IUCN Red List of Threatened Species, http://www.iucnredlist.org/details/132835.

NOAA, 2016: Endangered and Threatened Species; Identification of 14 Distinct Population Segments of the Humpback Whale (Megaptera novaeangliae) and Revision of Species-wide Listing. In: N. O. a. National Marine Fisheries Service (NMFS) and C. Atmospheric Administration (NOAA) (eds.). Department of Commerce, Washington DC, USA.

Pomilla, C., A. R. Amaral, T. Collins, G. Minton, K. Findlay, M. S. Leslie, L. Ponnampalam, R. Baldwin and H. Rosenbaum, 2014: The World’s Most Isolated and Distinct Whale Population? Humpback Whales of the Arabian Sea. PLoS ONE, 9, e114162.