Is Sri Lanka still best for Blue Whales?
By Gehan de Silva Wijeyeratne
Can Sri Lanka still claim to have the best encounter rate for Blue Whales on commercial whale watching trips?
In May 2008, I broke the story that Sri Lanka was Best for Blue Whale and publicised an encounter rate of 90%. It was a bold claim to make as it was based on a limited data set of 23 days with whale watching trips in April 2008. On these dates in April 2008, there had been an encounter rate of 100% and there were reasons to explain the presence of whales off the South coast at that time of the year. I had already branded Sri Lanka for leopard safaris and for the elephant gathering and had the experience to know when a wildlife spectacle was a periodic and predictable event, suitable for commercialisation.
As I made clear in that article, I drew on discussions with Dr. Charles Anderson who had based his views on strandings in the Maldives. He believed that an EastWest migration of Blue Whales took place between the Arabian Sea and the Bay of Bengal. Anderson had published papers in 1999 and 2005, in which his thoughts on Blue Whale distribution and movements within the Northern Indian Ocean were summarised. Anderson published a paper in 2012, which was an expansion of those ideas, including new sightings data from Sri Lanka. This was a formal, scientific paper with no claim of Sri Lanka being best for Blue Whale, let alone being a good location for Blue Whales. Neither did he publish any encounter rates for whale watching or refer to my shamelessly commercially oriented claims published earlier in 2008.
During the WhaleFest in October 2012 in Brighton, at the Bar of the Hilton, I asked him why it was that he did not even on his website claim that Sri Lanka is Best for Blue Whales. His frank reply was that he tends to think about these things in a different way, i.e. from a scientific rather than a commercial perspective. The next day at a talk I gave at WhaleFest which he attended, I referred to this conversation pointing out that it illustrates the different approach that he as a scientist and I as a developer of commercial wildlife tourism have taken with the same underlying story. Anderson brought out a meticulous scientific paper in 2012 carefully avoiding claims with a commercial agenda. In contrast I rushed out a commercially significant story based on a single season’s data, field experience, commercial intuition and faith in Anderson’s migration hypothesis.
I am always in search of big stories of international significance that will attract journalists and film crews. I saw the Best for Blue Whale story as a way to create livelihoods from wildlife tourism, especially important in a country that had experienced the Boxing Day tsunami in 2004 and was still in the middle of fighting a civil war with ruthless separatists. I also saw it as one of the best avenues through which to execute a conservation agenda. My strategy was ‘Conservation through Commerce’. However, I have always believed a good story should be substantiated with data and hands-on field experience. I have continued to collect data from whale watchers and the whale watching boat companies on encounter rates. So although Anderson and I may have differed substantially in how we sculpted the same raw material, we share a common interest in science and grounding our views in science.
It is useful to see if seven years later, the test of time has affirmed my intuition over Sri Lanka being ‘Best for Blue Whale’. The data I have on whale watching trip encounters is not collected to a rigorous scientific protocol. The collection of data has been sporadic, but I have compensated for this by only calculating encounter rates for months where there have been at least 10 sailings. An encounter in this context is seeing one or more Blue Whales on a whale watching trip. It is difficult to gauge how many different individual whales are being seen on a whale watching trip and it is not uncommon for whale watchers to multiple count the same whale that is diving and re-surfacing in different locations. Therefore a simple measure as whether one or more Blue Whales was seen or not works better as an indication of the likelihood of seeing a Blue Whale.
One of the biggest risks with this type of data which is not designed to a strict scientific protocol is that sailings on which whales are seen are more likely to be reported than sailings on which whales are not seen. This is especially true in the first few years when whale watching began and reporting of sightings was irregular. Thus there is risk that the data is biased towards a better encounter rate. Nevertheless, some data is better than mere conjecture and a few days with nil sightings which go unreported will not change the rates significantly.
The accompanying table is from a series of analyses which I have with Georgina Gemmell made available on-line in an intermittently updated deck of PowerPoint slides. Gemmell patiently logged into an Excel spreadsheet, data I had collected over the years. We also drew heavily for more recent years from data provided by Mirissa Water Sports, the pioneering whale watch tour operator in Mirissa. From an ad-hoc dataset of 992 sailings between April 1, 2008 and May 5, 2015, I have calculated the encounter rates for months where there have been 10 or more sailings available in the data. This more than ten sailings criteria avoids spurious results like a month which has had just one sailing and a sighting of a whale producing an encounter rate of 100%. The number of sailings used in the analysis with this restriction reduces only modestly to 942 sailings. This remains a good number of sailings from which to draw valid conclusions, subject to the caveats mentioned before.
The resulting encounter rates are very high, most within the range of 70%-90%, as shown in the table. Note that these are monthly encounter rates indicating the proportion of sailing in which one or more Blue Whales were seen.
In several of the peak whale watching months, the encounter rate exceeds 90%. This is best shown in the graph which shows the rates for the best three months in a calendar year. Despite the caveat mentioned earlier that the data from commercial whale watching is not robust as that collected to a scientific protocol, it is clear that the encounter rates are spectacularly high, especially for an animal that was once so hard to see.
Besides the encounter rate of Blue Whales, other interesting patterns emerge. For example on 98% of the 992 sailings from Mirissa, a marine mammal has been encountered. The encounter rate for any marine mammal could be treated as an overall ‘whale watching efficiency rate’. On this basis Mirissa has a staggering 98% efficiency. But this metric needs to be treated with caution. An encounter may be a fleeting glimpse in the distance of a dolphin or it could be one where a boat kept its engine on idle whilst Blue Whales fed beside the boat for an hour. An efficiency ratio does not shed light on the quality of the sighting. Neither does it tell you if the whale watching on that boat and that of surrounding boats was handled in a responsible way to contribute to an ethical and pleasurable experience.
An interesting result is in that there is no unambiguous trend in the encounter rates decreasing despite the surge in the number of whale watching boats. Given the accounts in the media of whale watching boats harassing the whales, a reduction in encounter rates may be expected. But we must be cautious in interpreting the data as the quality of the encounters could be lowered if whales are being harassed by boats. Whales could become harder to locate for an individual boat, but the overall encounter rate may remain high as there are more boats out there increasing the search effort and communicating by mobile phone to other boats when they find one. In 2008 and 2009, there were days when I was the only person out whale watching and encounter rates were entirely a measure of one boat’s effort. Nowadays, it is a collective effort.
On December 27,2014, a few months shy of seven years from April 1, 2008 when I first encountered both Blue and Sperm Whales on a sailing from Mirissa, I was out at sea again with Mirissa Water Sports. I observed how several boats had lined up neatly in a row on one side of two feeding Blue Whales. The whales had fed next to the boats for almost an hour. The boats were lined up in a text book style manner of responsible whale watching. I suspect this was partly accidental in that the line of approach to the whales resulted in the boats lining up rather than encircling them which would have driven them away. This good behaviour may also have been partly a result of several initiatives to both regulate and encourage responsible and ethical conduct when whale watching. One of the notable initiatives has been supported by Sri Lankan (the airline) in partnership with the UK based conservation charity Whale and Dolphin Conservation. Sri Lanka has a great tourism product in its Blue Whales but in terms of its overall offering, the responsible conduct of whale watching boats will be a defining factor in the future.
For a wildlife tourism product to be successful, it must satisfy the “Three Es”. These are a reliable Encounter Zone, Encounter Season and very importantly a good Encounter Rate. The Blue Whales, the leopards and the Elephant Gathering all satisfy the “Three Es” very well. In this article I focussed on the data that continues to support Sri Lanka’s claim to be a top whale watching destination, on the back of a good encounter rate for Blue Whales. But from the perspective of gaining column inches of international press coverage, a species need not satisfy the “Three Es” in the way required for commercial success.
A case in point is the yet mysterious Orcas that visit Sri Lanka. They are very rare, with usually just one or two records a year; even this being a recent phenomenon based on the presence of whale watching boats. The Orca Project Sri Lanka (OPSL) administered by Gemmell has, using a Citizen Science photo identification study identified 13 individual Orcas. A pair of them (OM001 and OK008) has been recorded from Mirissa, Trincomalee and Kalpitiya. Using information provided by whale watchers, Gemmell and others have already had a paper accepted for publication in Aquatic Mammals, a leading peer reviewed journal. The Facebook page has gained a number of followers and draws attention to cetacean research in Sri Lanka. Therefore even charismatic animals with low encounter rates can provide a country with international publicity.
For wildlife tourism, the marine mammal tourism works well with the island’s terrestrial offerings which have astonishing species richness per unit area basis, compared with other much larger tropical islands. For more details on this, my article on why Sri Lanka is superrich for wildlife can be easily retrieved from the web. Sri Lanka also has the largest annually recurring gathering of wild elephants and is outstanding for leopard. What more can you give an island that is super-rich for wildlife?