THE ANCIENT ONES
Separated from their global migratory family 70,000 years ago, a group of humpback whales have settled off the coast of Oman, making the waters of the Gulf their exclusive home for breeding and feeding in an unusual phenomenon still shrouded in mystery.
Story: Mohammed Shafeeqe / Photography: Darryl MacDonald/ESO | 1 January 2015
The Whales of the Arabian sea
Omani waters host a genetically unique population of humpback whales (Megaptera Novaeangliae) that, unlike the rest of their species, do not migrate, instead sticking to the waters of the Arabian Sea. The mystery behind the origins and habits of the Arabian Sea humpback whale are slowly being unravelled and the new findings from 15 years of research conducted by a team of marine experts led by Environmental Society of Oman (ESO), have triggered a buzz of excitement among marine experts across the globe. As a result of this the isolated population was given official international recognition along with a conservation status of ‘Endangered’ by the IUCN (International Union for Conservation of Nature) as the most recent estimate puts the population below 100 animals.
Arabian Humpbacks are rather mysterious, having only been discovered as a genetically distinct humpback population recently. Andrew Willson, Senior Marine Ecologist with project partner Five Oceans Environmental Services, explained that much of the biology of these whales is understood from the scientific records of Soviet Whaling vessels that illegally took over 2,600 whales from the Arabian Sea between 1964 and 1967, 242 of which were humpbacks. This information was released with the break-up of the Soviet Union in the early 1990s and revived the interest in solving the enigma of these whales being far off the regular migratory track to southern ocean feeding grounds. Current work now relies on a host of cutting edge research techniques including molecular genetics, acoustic song detection, and tracking whales with satellite tags.
Studies from the first five years of the research established that these whales became isolated during the onset of the last ice age, 70,000 years ago. This was revealed by comparing their genetic sequences with those from elsewhere in the Indian Ocean and Atlantic Ocean. “They don’t travel from the tropical areas in the winter to the feeding areas in the polar region, which is the conventional trait for this species, a reason why there is global scientific interest in the population – it may allow us to understand more clearly what is the driver behind the migration of other populations of whales,” said Andrew. “Understanding this more clearly may eventually allow us to understand the implications of climate change on these species.”
“The current theory is that the whales are sustained in the Northern Indian Ocean as a result of highly productive upwelling of oceanic waters driven by the monsoon or ‘Khareef’ that blows across Southern Arabia between June and September every year. Nutrient laden cooler waters support a diverse food web including sardines, which we know from the Soviet whaling records are target prey for this population.”
“The most important findings are that we have very few whales and that areas recently identified as important habitats are in the spotlight for future development. This scenario has resulted in international interest in the plight of this population and stimulated ESO and project partners to ensure that sufficient information is available to guide these developments. Fishing, hydrocarbon exploration and increase in regional and local shipping traffic are emerging activities that present threats to whales ranging between the Gulf of Masirah and the Hallaniyat Islands. Population level threats can be experienced by accidental capture of whales by local fisheries and direct mortality from ship strikes, with on-going chronic stresses resulting from increasing noise and industrialisation of coastal areas.”
A 2008 study showed that 40% of humpbacks encountered in Oman showed signs of net entanglement, and this situation is not unique to Oman. The threats that shipping presents to whales has also become a global concern with the International Whaling Commission setting up a committee to look into the matter and liaise with other international bodies to identify high risk areas for ship strikes and to provide solutions to decrease ship noise in -sensitive habitats.
“The situation for these whales in Oman is starting to look precarious, but furnished with the necessary ecological data and the support of industry we are confident that solutions can be found to allow whales and new developments to co-exist. First of all, we must have a clearer understanding of where these whales are and when.”
“The most important findings are that we have very few whales and that areas recently identified as important habitats are in the spotlight for future development”.
Listen to "Scooby", an endangered Arabian sea humpback whale. Singing somewhere off the coast of Oman.
Finding the Whales
Initial research conducted from small boats by a mobile research team honed in on where to find whales in the early 2000s, and started to generate a photographic catalogue of them and collected genetic samples. Hampered by the constraints of working from small boats and the amount of time they could spend at sea, the team started to look into alternative monitoring techniques.
Humpbacks are very well known for their exquisite songs. It is only the male who sings during the breeding time. In 2011 the first array of acoustic recorders was deployed off southern Oman. “The acoustic loggers were the first break through in changing the research approach to define habitat of the animals by using remote detection technologies. Whales are known to communicate with each other through vocalisations, so by leaving acoustic recorders on the seabed year round we now have records that will indicate to us the seasonality of their presence in multiple areas simultaneously.”
Data collected between 2011 and 2014 is now being processed by project partners in the New England Aquarium, and financed under sponsorship arranged between ESO and Shell Development. Preliminary results from this work should be out within the next six months.
Andrew explained that no single technique can provide all the necessary data to generate a representative seasonal and spatial picture of what these animals are doing. So, with an approach to gain multiple lines of evidence on whale ecology, the team launched a two-year satellite tagging campaign.
Following the Mammals
In continuation of the ESO research programme a team of 10 scientists recently returned to Muscat after spending two weeks at sea tagging these rare marine mammals. The field team lived on a fishing dhow throughout the expedition and used two smaller boats to support the tagging operations. The team was led by Five Oceans Environmental Consultants, including experts from Environment Society of Oman and international groups Institute Aqualie, National Atmospheric and Oceanic Administration, and the Wildlife Conservation Society.
Through the tagging, the researchers are now able to track the movement of the whales off the cost of Oman. “The objective of the tagging is to define important habitats for the whales through the movements generated by locations transmitted by the tags several times a day,” said Andrew. “The plots themselves will enable us to understand the accumulated time spent in certain areas, their behaviour, and what depths they are diving to.”
The most recent expedition was in the Gulf of Masirah, following two previous tagging expeditions in February 2014 and March 2015 in Dhofar where the data from six tags revealed these whales are spending significant time around the Hallaniyat Islands and Gulf of Masirah (between Barr al Hikman in the North, Masirah Island to the East and Ras Madrakah to the South).
Satellite tags only remain on the whales for a month or two, though last season one of the tags lasted for almost six months and revealed that the whale moved as far south as Yemen. Once whales were tagged the team continued to survey the area for the remainder of the expedition, collecting photographic and genetic data that will be used to define population estimates in the future.
In March 2015 three whales were fitted with satellite tags off the southern coast of Oman. This is the animated track of one of the whales ‘Nusf al Qamar’ or Halfmoon.
The public can follow the whale's movements.
The tracks can be seen
The ESO has developed a network of partners to ensure that this information is used to help guide decision making and management of activities in the Gulf of Masirah. The work is being annually reported to the International Whaling Commission Scientific Committee who has taken an interest in encouraging appropriate conservation measures to be adopted for these unique creatures.
This is critical as the tracks are already showing movement across the approaches to the port in Duqm and across an area where there is active hydrocarbon exploration. Already active with their own whale management scheme, the Port of Duqm has sponsored one of the tags to support the efforts.
“We are only just beginning to scratch the surface of the importance of these whales to the ecosystem, so as well as being interested in their own conservation we are also interested in their importance as indicators to the general health of the seas. In the grander scheme it is a proactive way to investigate the state of the environment and the resources upon which we all depend.
“So where development is taking place we need to ensure decision makers have the necessary information to put equal measures into the most effective solutions to ensure progress is sustainable.
In January last year a group of whale scientists, research institutions and NGOs formed the Arabian Sea Whale Network (ASWN), to share scientific data on these whales. “Collaborators in the network hail from Yemen, UAE, Iran, Pakistan, India, Sri Lanka, and Maldives. These countries represent the area we think is part of the geographic range of these whales and will address a key goal to start improving our knowledge of the animals outside of Oman, of which we know very little.”
“Findings on this work are routinely handed to government partners in the Ministry of Agriculture and Fisheries and Ministry of Environment,” Andrew said, adding, “the International Whaling Commission Scientific Committee is extremely interested in the progress in the activities and have assigned the Arabian Sea humpback whale their own space in their agenda. They are very supportive of having the work we initiated in Oman replicated in other countries in the region.”
Andrew said that finding funding to adequately resource such research is always a challenge. “Recent funders including Renaissance, Shell, and Port of Duqm demonstrate that there are companies operating within Oman that are interested in taking responsibility for such conservation efforts. We hope that as the project generates more information and awareness on these animals that this proactive approach will be welcomed and emulated by other industries operating in the area. Certainly more efforts are required to also investigate solutions to threats and how these solutions can be implemented.”
These spectacular creatures that have made the Sea of Oman their home are one of the many unique natural wonders of this country, though many aren’t aware of their presence, or of their peril. Proactive protection is key to their survival, and essential to this end is an awareness that will lead to widespread appreciation for this aquatic gift.— [email protected]
How you can help
• Submit photographs of whales and dolphins
spotted in Oman to ESO.
• Report incidents of whales or dolphins in
distress and tell ESO about any dead whales and dolphins that you have seen.
• Assist with data entry and the management of
ESO’s reference library.
• Assist with scientific surveys (requires
experience with boat-handling and a willingness to spend long hours staring at empty sea!).
• Assist with beach surveys for cetacean remains
(requires a strong stomach and an interest in examining dead whales and dolphins).
• Assist with presentations to schools and local
communities (group members can provide some presentation materials and training – but presentation or teaching experience would help).
• Assist with translation of reports and articles into
• Assist in the formation of a national
entanglement and stranding reporting network.