A rough-toothed dolphin, spotted only once before in the UAE, was among six species of dolphins sighted during a survey carried out by a team of scientists in Fujairah.
The rough-toothed dolphin (steno bredanensis) is one of the larger species of dolphins typically found in deep tropical waters and is identified by their conical heads and slender noses.
The first sighting of the species in the Emirates was during a similar survey carried out in 2018.
It was one of six different species of dolphins found during the five-day survey between March 21 and 25, which was carried out jointly by Fujairah Environment Authority, Fujairah Research Centre and Five Oceans Environmental Services.
The team of eight surveyed deep, offshore waters up to 70 kilometres off the Fujairah coast using vessels as well as a helicopter.
They followed a similar approach to previous surveys to ensure a direct comparison could be made between results from previous years, and between seasons.
“The surveys involved helicopter flights along pre-determined transect lines, which are also followed by survey vessels, including one provided by the Port of Fujairah, a partner in the project,” said Aseela Abdullah Moalla, director general of Fujairah Environment Authority.
“Transects are scientifically devised to ensure that results are statistically viable and that maximum coverage is provided as the team search, from dawn to dusk, for whales and dolphins.”
During the survey, the team had 37 separate encounters with dolphins. The rough-toothed dolphin was found among a mixed group that included common bottlenose dolphins (tursiops truncatus), which were feeding in waters 50km off the shore.
“Both species were accompanied by juveniles and calves, suggesting breeding status in Fujairah waters,” Ms Moalla said.
“Common bottlenose dolphins were also sighted on many other occasions during the survey and are now known to be the most common and widespread of the dolphin species off Fujairah.”
Less common, but increasingly seen during the survey, were striped dolphins (stenella coeruleoalba), known for their striking markings, including stripes and blazes across the head and body.
“Elsewhere in the Arabian region, this species is only very rarely recorded, perhaps due to a lack of observation in deep, offshore waters where it is most at home,” Ms Moalla said.
A close relative of the striped dolphin, the spinner dolphin (S. longirostris) — known for its acrobatic spinning behaviour — was also seen during the survey.
The Risso’s dolphin (grampus griseus), a deep-diving specialist, was encountered once during the survey in water depths of more than 1,000 metres.
Risso’s dolphin can descend to the seabed for extended periods in search of its favoured food, deep-sea squid, which it hunts in total darkness using sonar to locate the prey.
The sixth species observed during the survey was the Indo-Pacific common dolphin (delphinus delphis tropicalis), which is among the few species found closer to shore in shallower waters off Fujairah.
“Here it is more threatened by vessel traffic than in the less busy, offshore waters, but its ecological needs tie it to these waters which it must share with thousands of vessels, large and small,” said Ms Moalla.
“It even inhabits waters within the Port of Fujairah Offshore Anchorage Area.”
She said the surveys contributed to ongoing work to establish the distribution, relative abundance, seasonality and behaviour of whales and dolphins off Fujairah. They also identify their most valuable habitats to provide them protection from shipping traffic, fishing activities, pollution and other threats.