[Research & Fieldwork]

Autumn 2004 Survey - Masirah

The Oman Whale and Dolphin Research Group recently returned from their fourth major survey in the Gulf of Masirah. As in the previous surveys conducted in 2000, 2001 and 2002. The group focused on collecting behavioural and ecological data on humpback whales and various other cetacean species found in the area. After a bumpy start, when the wheel bearings of the boat trailer were damaged en route to Masirah Island, members of the group saw much better times in the days that followed.

- A humpback whale breaches in the Gulf of Masirah.They they have now been confirmed to be a non-migratory humpback whale population -

Surveys were conducted for nearly 3 weeks in November, after weeks of prior preparation, and subsequently a few more weeks were dedicated to entering data after the survey ended. Although the group’s base camp was on the southern end of Masirah Island, the group’s 6.5m RIB ventured out daily up to 100km to the east and south of the island, across to Barr al Hikman and the Ghubbhat Hashish, as well as up the Masirah channel. Members of the group were on the lookout from sunrise to sunset, observing nearshore species such as bottlenose and humpback dolphins, and species that occurred further offshore such as humpback whales, Bryde’s whales and common dolphins.

Humpback whales, as in the past, were the main target species of the survey. This species is of particular interest as, after four years of collecting data, results have confirmed suspicions that the Arabian Sea population is the only documented non-migratory population of humpback whales in the world. The Arabian Sea population was heavily impacted by illegal Soviet whaling in the 1960’s. Therefore, understanding of their feeding and breeding behaviour, and ecology is vital for the development of good conservation and proper management efforts.

- Distinctive markings on this humpback whale’s tail flukes identified it as one of the nine new individuals that were encountered on the survey -

12 humpback whales were sighted on this survey. Of the 12 individuals, skin samples for genetic analysis were taken from 10 of them. It was a challenge carefully maneuvering the research boat around the whales, to take photographs and skin samples, as the whales were often difficult to approach. However, with good coordination and excellent team effort, very valuable data was collected. Analysis of skin samples that were taken on past surveys have shown that although humpback whales in sampled in Oman share certain characteristics with populations from Madagascar, South Africa and the Comoros Islands, some individuals represent a completely unique genetic lineage only found in Oman. Skin samples taken on this survey will be analysed in the same manner, to further the study of the relationship between the Oman humpback whale population and other populations in neigbouring Indian Ocean regions.

Humpback whale song, an activity linked to the breeding season, and only observed in males, was only detected on one occasion during this survey, albeit faintly. This was surprising, as humpback whale song was not expected during this time of year. Further research is needed to investigate the time during which males start singing, possibly as a means of setting up territory in preparation for the mating season that typically lasts from January to May.

- Bottlenose dolphins were frequently encountered throughout the survey, mostly near the shore -

One of the most important elements of humpback whale research is individual identification through photographing the dorsal fin and undersides of the animal’s tail flukes, the colour, scarring and shape of which are unique to each individual. This time, OWDRG encountered 3 “old friends”, who have been sighted on past surveys. Of these three, one was last sighted in the year 2000. After checking through the Oman Cetacean Database, it was discovered that 9 new individual humpback whales were encountered. Re-sightings of individual whales can give insights into their distribution and seasonal movements. Here in Oman, re-sights of individual whales have been high, an indication that the Omani population is relatively small and is in greater need of protection than previously thought.

This survey yielded the highest number of Bryde’s whale sightings in all of OWDRG’s surveys. Photo-identification work on this species may also be possible and valuable for conservation efforts. Other species that were encountered on this survey include common dolphins (a large group numbering approximately 1000 animals), bottlenose dolphins, humpback dolphins, and an unusual sighting of false killer whales. These encounters yielded a wealth of photographs and video footage which can be used by the OWDRG for public awareness-raising and educational materials, such as “Whales and dolphins of Arabia”, by Robert Baldwin, and the recently released PDO sponsored interactive CD on Oman’s marine environment.

- An unusual sighting of false killer whales just east of Masirah Island (a first for the team) -

This survey was conducted with cooperation on a local, regional and international level. The OWDRG is a unit made up of volunteer scientists. The group is now proud to have become a part of the marine subcommittee within the newly founded Environment Society of Oman (ESO). All future work, including ongoing surveys in the Muscat area conducted by OWDRG member Ms. Louisa Ponnampalam, focusing on the behaviour, ecology and habitat use of spinner and common dolphins, will be conducted as part of the ESO.

As usual, all the data that were collected by the OWDRG on this survey will be used to further our understanding of the distribution and ecology of cetaceans in Oman. It will also be used to forge cooperative conservation efforts with various local Government bodies to protect the critical habitat of these marine mammals.

On the Masirah survey, core members of OWDRG were joined by Mr. Tim Collins, who was once based here, but recently took up a position with the Wildlife Conservation Society to conduct humpback whale research off the pristine coasts of Gabon. The survey also had the privilege of the experience and skills of Ms. Brenda Rone, a whale researcher attached to the US National Marine Fisheries Service. Their participation in this survey was made possible by sponsorship from Salalah Port Services.

This survey would not have been possible without funding and sponsorship, permissions and logistic support from: the Ministry of Agriculture and Fisheries, the Ministry of Regional Municipalities, Environment and Water Resources, Shell Oman Marketing, Veritas Geophysical, Salalah Port Services, Five Oceans L.L.C., Tisco/Tawoos, the American British Academy, the Sultan’s School, Thuraya and DHL Worldwide Express.