It is a great privilege to swim with the biggest whale on earth. One of the only places that allows the opportunity to see a Blue whale underwater is in Sri Lanka.
There is another hour left before the morning sun wakes the sleepy town of Mirissa and we slowly rise out of bed and put on our bathing suits. The excitement starts creeping in as we have no idea what the day holds except that we are going to be snorkelling with the biggest animal on the planet.
The tuk tuk picks us up at 6:30am in front of our hotel and meanders its way through the streets towards our boat. On arrival, we are greeted by a few friendly locals and an unspoken language of both excitement and wonder is written on everyone’s faces.
We head out to sea as the morning sun starts rising towards the East and lights the way on the calm ocean. We don our fins and get our cameras ready because luck could strike at any moment. It doesn’t take long before the first spray of water is spotted in the distance and the chase begins. We only have a few minutes while it takes a few breaths and disappears into the depths to feed.
The Blue whale Balaenoptera musculus is the largest animal on the earth with the largest recorded size of 30.5 m. Biologists speculate that their ability to evolve to such a large size over the years is due to a lack of natural predators. Sri Lanka is a hotspot for a wide range of whale species, particularly the Pygmy Blue whale Balaenoptera musculus brevicauda which is a sub species of the Blue Whale. These species are resident to the area due to an abundance of food that can be found all year round. A geological feature is known to be found 20 km offshore where a steep drop in the ocean floor has resulted in Zooplankton rising towards the surface in an oceanic process known as upwelling. The Blue whales feed at a depth of 200m where they can stay for 10-15 minutes before returning to the surface for air. Blue whales have small lungs relative to their body size which is an adaptation for deep diving. Their lungs ability to absorb oxygen and rapidly diffuse it throughout their body is what makes them such successful divers.
To be in the water with a Blue whale is a truly humbling experience. Swimming in the vast open ocean in an environment that is unfamiliar, and then to come across one of its biggest inhabitants is an amazing experience. An interaction lasts for no longer than 15 seconds but during that time it is immediately apparent that the whales all have different characteristic traits. Our most memorable experience was with the oldest and largest whale who was characterised by a white spot on the tip of his nose. He was not at all bothered by our presence and slowly swam past us in all his majesty. We nicknamed him “Toppie” who we managed to see again on another day. Similarly, another whale was characterised by a big white scar close to his pectoral fin. The scar was more than likely induced by a ship strike. On a few occasions, as the whale swam passed it would tilt its whole body at an angle in order to get a better look at us with one eye. On occasion there would be a big thrust of the tail, which reached a height of 10m, and the whale was gone within a few seconds. Sometimes, however, it would be possible to spend a few minutes swimming behind them and almost catching up to them again.
Blue whale sounds cannot be heard underwater, however, a GoPro could pick up the sounds once played back on a computer. Their sound is quite distinctive and varied. It could possibly be equated to the sound of winding up a toy car and on one occasion the whale sounded like a small primate calling through the jungle.
The only way to spot these animals in the vast open ocean is when the whale exhales at the surface, releasing a spray of water into the air that had been resting close to its blow hole. All Baleen whale species are known to have a divided blowhole and the air comes out with such force that it forms a water cloud above its head. There was one particular whale that had been hit by a ship and had a problem with his blowhole. He was difficult to spot because there was no apparent spray visible when he surfaced. Instead we had to look out for his tail and guess in which direction he was going surface 10 minutes later.
As the morning in Sri Lanka gained momentum, someone on the boat noticed a rectangular bulbous head protruding from the surface of the water. A single spray blown slightly towards the left was immediately identified as a Sperm whale Physeter macrocephalus. The year before, we came to Sri Lanka looking for Blue whales and we were privileged to spend the morning swimming with a pod of female Sperm whales. This year we were lucky enough to come across a Bull Sperm whale swimming with a definite purpose. Sperm whales feed mainly on Giant squid which are mostly found at depths of 2 000m. My first experience having a female Sperm whale swim past me was that of nervousness because of their large size and gaping mouth showing big teeth. This Bull Sperm whale was double the size of the females that we had previously seen and attained a size of roughly 17 m. They have the most unusual shaped mouth and one is instantly in awe due to their unusual shaped head. Their head contains a waxy cuticle called spermaceti which aids in their ability to dive to great depths. Similar to the Blue whale, they have small lungs in comparison to their body size and a flexible rib cage to withstand the big changes in pressure as they descend and ascend. Bradycardia is a term used for slowing down the heart rate, and is an adaptation for diving vertebrates to ensure that there is sufficient oxygen supply to the vital organs of the body whilst diving. Sperm whales can stay underwater for 2 hours and have therefore developed physiological adaptations to ensure their survival.
Other varieties of whales include the Omura whale Balaenoptera omurai which has recently been sighted off the coast of Sri Lanka was also possibly spotted on one of our mornings. This is an incredibly rare whale species as they are very elusive. They are commonly called the Dwarf Fin whale. A pod of fast swimming False Killer whales were also seen in the distance. In 2012 Orcas Orcinus orca were seen predating on a Sperm whale. We did not manage to see any on our trips although they had been spotted in the area.
When enough boat time has been had, there is a turtle sanctuary close to shore where one can get the opportunity to snorkel with turtles. Sri Lanka is home to five of the seven turtle species and the species that can be found on the snorkelling excursion is the Green turtle Chelonia mydas. The visibility close to shore is moderate compared to the open ocean, nevertheless, it is still a great encounter with turtles. If one is interested in photography, it is possible to get a good shot as it feeds on the algae growing off the hard coral three meters below the surface.
There are many risks that these marine animals face on a daily basis. One of the busiest shipping lanes in the world passes the southern coast of Sri Lanka where whales are constantly at risk of being hit. There are currently three lanes close to Sri Lanka and these large animals have to navigate their way through busy ship traffic in order to reach their food source. Plastic pollution is also putting the whales’ lives at risk. Microplastic was evident in the pelagic zone as the current pushed it along in its direction of flow. This is one of the most harmful forms of pollution in our oceans because it can be ingested by organisms at the bottom of the food chain, such as krill, which then makes its way up to the organisms at the top of the food chain, such as the Blue whale on which these organisms predate. Witnessing this kind of pollution has made me realise that our planet is in desperate need of an alternative to plastic.
A day of swimming with whales usually ended around noon. By this time we had spent most of our energy clambering in and out of the boat and trying to get our best underwater whale encounter possible. The return to shore is welcomed by a few friendly local faces as they assist in landing the boat on to shore. The skipper has superior boating skills and not only manages to land us in the right place to get the best possible interaction with a whale but also has the ability to get the boat safely back onto a rocky shore. The afternoon is spent going through our pictures and looking for the best shot of the day whilst sipping a cocktail on the beach. The morning seemed so surreal, and whilst tirelessly chatting to each other about our encounters, it helped us to relive a truly magical experience.