Sperm whale superpods in Sri Lanka: A natural phenomenon missed due to the pandemic
By Jithendri Gomes
Amidst the disruption Covid-19 has brought about is also the disruption to planned field research. Researchers have missed out on the narrow window to observe the spectacle that is the sperm whale superpod as the Covid-19 pandemic has forced an entire nation to shut down.
Previous data suggests that the peak of the superpod season this year would run from 15 March to 20 April.
Conservation biologist Ranil Nanayakkara has been following these superpods for the last 10 years. His research interests are biogeography, ecology, and taxonomy. He currently serves as a Co-founder and Research Scientist at Biodiversity Education and Research (BEAR) and is also attached to the University of Kelaniya. He spoke to The Sunday Morning Brunch about how he encountered these super pods for the first time back in 2010 and the journey of documenting them ever since.
“A super pod is a mass aggregation of whales found in one place. Sperm whales generally are found in small pods of one to two up to about 15 to 20. There have been, however, instances where in Mirissa and Trincomalee, these pods have increased to around 30 to 50 individuals. In the Eastern half of the Gulf of Mannar to where we venture out from the Kudawa area in Kalpitiya, we have encountered a large aggregate of sperm whales numbering up to 300-plus individuals on several occasions,” he shared.
“I have been monitoring this phenomenon since 2010 with the end of the war in 2009. At the time, I was attached to a different marine research organisation. The people in Kalpitiya have been witnessing this since their forefathers’ time. The story has come down through generations through word of mouth that these aggregations happen from March up until May,” Nanayakkara added.
He went on to explain as to why these aggregations happen in the first place. “We first thought that perhaps these aggregations happen because of the nutrient levels in the water, with it being higher than in other areas – a place where planktons are more and the larger predators follow it there. So we tested out samples with water quality tests and found that there isn’t a huge fluctuation of nutrients from other areas. We then started focusing on other research areas.”
He mentioned how in the next step, they got into the water to photograph the animals with permission and clearance in place. This was done in order to identify the whales and include them into the ID catalogue they have put together. They identify them with scars and marks that naturally occur and also by encountering predator-like killer whales. “It is when we started this process that we realised that the sperm whales come to this particular place to mate.”
The sperm whale is also different to other kinds like blue whales as they hang out in social family groups. Once the males mature when they reach the age of 10 to 12, they leave the group and wander away, similar to elephants. They also go into colder water and when they are ready to reproduce, they come in search of the receptive females. With almost 10 years of following them in the Gulf of Mannar, Nanayakkara and his team has collected and compiled footage of this phenomenon.
“We also use the hydrophones to record their CODARs (coastal ocean dynamics applications radar). Researches done in other parts of the world have shown that they have a dialect of their own language in different parts of the world, similar to humans. The ones found in the Indian Ocean will be different to the ones found in the Mediterranean waters. They have a different frequency of the CODARs. We have been maintaining a CODAR ID catalogue as well,” he explained.
This method was also adopted to see if the same individuals are returning every year. With this, they have also been able to record them lunching, sky hopping, and tail flapping.
Only in Sri Lanka
This phenomenon that happens annually in Sri Lanka is also supposed to be very unique to the world. It does not happen anywhere else in the region as well. “We have been in touch with the Authority of Sperm Whales in Canada and they have been studying sperm whales since the 1970s. They have also confirmed that this phenomenon is very rare and that these large aggregations happen only in very few places all over the world. A large gathering is what happens in the Gulf of Mannar and aggregations similar to this one was only witnessed previously, prior to whaling times,” Nanayakkara said.
Whaling is the hunting of whales for their usable products such as meat and blubber. It was in the 1970s that this activity was banned, protecting all ocean whales. Records show that the moment the ban was in place, they were able to witness these large aggregations.
Nanayakkara further explained that it has also been acknowledged and confirmed by the Whale and Dolphin Conservation in the UK. They have written many articles to renowned papers like The Guardian regarding this natural phenomenon. Furthermore, he explained that no research or observations of these superpods were done in Sri Lanka prior to 2010 and his work.
“Even for me, it was a mere coincidence to find it. I too didn’t know about it until I came across it while doing a marine mammal survey in the area and decided to follow a tip given by the fishermen who told us that they saw a large number of sperm whales about one-and-a-half nautical miles from where we were in the sea.
“We went anticipating to see around five to 10 whales and found close to 50 on the surface alone! And with sperm whales, if you get 50 on the surface, there would be many more underwater. It was from then on that every year we went back to Kalpitiya to observe this whilst engaging in other research as well. And now we have data of 10 years; in 2013, the Whale and Dolphin Conservation also came on board to go along with me every year,” he noted.
With it being identified as one of the largest congregations in the world, Nanayakkara explained that the next phase of the research will be based on a consensus to identify why these animals come to this area specifically. “The authorities state the Gulf of Mannar is secure from three sides: On one side you find India, on the other Sri Lanka, and finally Adam’s Bridge. Only the southern part is open to the deep seas. So it is a good and secure place for them to come and relax and also calves, and mate free of predators,” he explained.
A unique phenomenon such as this can easily attract a large number of people. However, with Sri Lanka’s whale-watching practices that are unmonitored, it can have a negative impact. Nanayakkara also mentioned that since 2013, they have been conducting workshops in both the Mirissa and Kalpitiya areas on responsible whale-watching practices. He also mentioned that comparatively, the people in Kalpitiya are more knowledgeable and responsible, and the boats that go out from Kalpitiya are the 19-feet fiberglass boats.
“These are the same people who used to kill dolphins in the past, but with the workshops, they have converted and come to an understanding that they are better off conserving these animals as opposed to harassing and killing them.
“We are also not publicising our research a lot and many Sri Lankans are unaware of this. But it is something that is well known abroad and we do have a lot of foreigners coming down to witness it and even film crews that come to do documentaries. We also have people who get special permission and come to take underwater photographs of these superpods. On a global scale, it is something very well known. We also came across a unique event in 2017 where a pod of transient killer whales started to attack these sperm whales. That too was documented and published in The Guardian,” he said.
Nanayakkara explained that superpods are best identified between 15 March and 15 April and it does coincide with the Kalpitiya whale-watching season that starts in mid-February all the way till mid-May. But with the superpods, all the creatures in the Indian Ocean gather in the Gulf of Mannar.
It certainly is a national treasure and we must work towards preserving this natural phenomenon that is unique to Sri Lanka.
Photos Ranil Nanayakkara