SEMPORNA: Marine experts are conducting close studies to collect data on sightings of aquatic mammals in the Semporna region.
The region has been identified as a key part of the Western Celebes Sea Drop Off "Area Of Interest", as designated by the IUCN Marine Mammals Protected Areas Task Force, because of the high number of marine mammal sightings reported there.
The sighting of four orcas near Pulau Sipadan last month fueled further encouragement for experts to study the occurrence to highlight the importance of the Semporna region for marine mammals and provide valuable data for ongoing cetacean studies in the area.
The Society of Marine Mammalogy SSM funded a conservation arm of the Semporna-based diver centre Scuba Junkie (Scuba Junkie SEAS) to assist in conducting a study on whales, dolphins and porpoise in partnership with national non-governmental organisations (NGOs).
Such a collaboration transpired following numerous discoveries of dolphins, particularly killer whales or orcas, using the sea channel in Semporna at their migratory routes through the Sulu and Celebes Seas.
SSM Head of Awards Committee Dr Lindsay Porter, in a statement said the partnership had enabled training to be given to local dive operator staff so they could receive good imagery and clear descriptions from such encounters.
"For many of the marine mammal species seen in the Semporna region, their use of the area is still unknown.
"It may be seasonal, to fulfil critical aspects of lifecycle patterns, for example shelter for mothers and young calves or transient, as part of a migration route or larger oceanic passages," she said.
Porter also said dive operators have also assisted this study by deploying acoustic monitors on the seabed to record marine mammal vocalizations, from which species identification can often be made.
She said the use of acoustics has allowed marine researchers to consistently monitor the area more.
"Meaning, that species identification does not solely rely on opportunistic sightings. The acoustic recordings provide us with a detailed soundtrack of marine mammal vocalisations, which will provide us with a more detailed picture of how the mammals use this area," she added.
To date, 21 species of marine mammals have been recorded, most of which are oceanic or deep-water species.
Many of the species sighted are poorly understood, meaning that their presence in the Semporna region presents a unique opportunity for researchers to find out more about these enigmatic species – even if it is just to confirm a sighting.
The recent sighting of orcas near Sipadan is not uncommon for the Semporna region. Such encounter was recorded by a divemaster from Scuba Junkie.
It shows two adult orcas and two calves swimming to the north of Sipadan, with one of the adults seen splashing the surface of the water with its tail – "lobtailing".
Porter stressed reporting sightings is vitally important to the success of these projects but cautioned observers to behave responsibly around all marine animals when trying to get footage.
"I applaud the divemasters at Scuba Junkie for their care and attention in their encounter with the orcas.
"Keeping their distance and not entering the water because they could see two calves, rightly surmising that the adults could be protective of the young. It is quite possible the 'lobtailing' seen was a warning to the boat not to get too close," she explained.
Meanwhile, Scuba Junkie conservation manager David McCann said he was glad to working with researchers and other NGOs to further understand the unique marine environment in this region.
"This is not the first time we have seen an orca with a calf in this area - notably there was an incredible encounter when divers with Scuba Junkie witnessed an orca and calf eating a sunfish in 2019.
"Examining whether this area has an important role for mothers and calves would be of great interest to many parties," he said.