Gehan de Silva Wijeyeratne in another game changing article brings together new data to publicise a commercially feasible strike rate for Blue Whales during the East Coast season from March to August


The article below was originally published in the Sunday Times (Sri Lanka) on Sunday 4th September 2011. It may be reproduced subject to the source of original publication being quoted. The revised version below includes a few changes, most notably a Summary



Recent data (especially from the Sri Lankan Navy) points to a commercially feasible strike rate for whales which extends Sri Lanka’s Blue Whale watching season from May to August off Trincomalee. This over-turns the prevailing view that the Blue Whale season finishes in April. Whale watching can now become commercially established during the ‘East Coast Season’.
The combined Mirissa (December to April) and Trincomalee (March to August) seasons for watching Blue Whale now gives Sri Lanka the longest and best Blue Whale watching season in the world, spanning at least 9 months.

During May to August, Blue Whales remain  close, around 6-8 nautical miles East of Trincomalee, about 30 minutes in travel time.

Koneswaram Temple atop Swamy Rock is the best publicly accessible on-shore whale watch point in the world for watching Blue Whales.

After beaches, the Blue Whales may be the most important focal point for East coast tourism. As a story for the international media which lends to TV documentaries, the publicity could generate thousands of room nights for Sri Lanka’s East Coast.

Between March to August, Trincomalee has a combined strike rate of over 80 per cent for Blue and Sperm Whales. More data is needed at species level. Dolphins (mainly Spinner Dolphins) have a higher strike rate.

The Gathering (of Elephants) and East Coast Blues will coincide. Much of Sri Lanka’s top wildlife assets are to the left of the Diagonal (a line connecting Yala and Mannar). Now the right side of the Diagonal will have stronger revenue generating wildlife assets.

The South-west monsoon can create choppy conditions off-shore during the East Coast season and the small 14 foot boats may be more limited in the time and distance they can travel when looking for Blue and Sperm Whales.



It is five in the morning and Orion the hunter is lying on his side suspended over the horizon. Directly over me is Jupiter and through my Swarovski binoculars I can make out two of its moons on opposite sides. A line drawn from the middle star of Orion’s sword and through his head points the way to the North. I make a note of the direction in which I must travel. I want to cut through the cluster of Blue Whale sightings which have been marked over a Survey Department map on the wall of the naturalist’s room at the Chaaya Blue Hotel. Mohan Sahabandu and A.G. Gayan, two of the Chaaya Blue naturalists ensure that an extra tank of fuel is loaded on the boat. My research trips can be long. I show Gayan the Orion nebula, a fuzzy patch on Orion’s sword, where a starhad turned supernova and exploded. It’s fuzzy; somewhat like my chances of seeing a Blue Whale out here on a single trip because it’s 5th August and most of the Blue Whales should now have returned to the Arabian Sea. In May 2008, I went international with credible data for the hypothesis by Dr. Charles Anderson that an East -West migration of Blue Whales brings significant numbers into Sri Lankan waters in a movement between the Arabian Sea off the Horn of Africa and the Bay of Bengal. The data so far, seems to back this up. During the whale watching season during December to mid April, Blue Whales are seen easily off Mirissa as well as Trincomalee.

The timing and direction of travel predicted by Anderson had been holding up well. He had predicted that they would be travelling East in December/January and West in April. For example, on 5th November 2010, Anoma Alagiyawadu, the Jetwing Lighthouse naturalist observed a spectacular movement of at least 25 Blue Whales travelling East past Mirissa. By December there were a good number of Blue Whales off both Mirissa and Trincomalee for the 2010/2011 season.

Earlier, the data for the tail end of the 2009/2010 season had also strengthened the hypothesis. We had some data points where we had checked that that the Blue Whales off Trincomalee were thinning off, as expected. On 2nd May and 3rd May 2010 Jetwing Eco Holidays naturalist Suchithra Hettiarchchi whale watched with Dr. Charles Anderson. They glimpsed a Blue Whale on the 3rd of May. They called off a third scheduled trip to sea as it seemed the Blue Whales had largely left. On 5th and 6th May, Chitral Jayatilake had another stab and saw a Blue Whale on the 6th.  On 19th May 2010, with Jetwing Eco Holidays naturalists Supurna Hettiarachchi and Suchithra Hettiarachchi and operations staff Ganganath Weerasinghe and Riaz Cader, I looked for Blue Whales and failed. So it seemed that Trincomalees’s Blue Whale season ended at the same time as it did for Mirissa.

In April 2011, on a two week visit to Sri Lanka, I once again concentrated my efforts to collect more data on the Sperm Whale Line which is just 15 minutes by boat off the Kalpitiya Peninsula. However, I spoke to Chitral Jayatilake, the Head of Eco-Tourism of John Keells Hotels for a data check. The frequency of sightings and numbers had dwindled and at best they were seeing just one or two Blue Whales since mid April. In contrast, when I sailed on the 27th of April 2011 from Mirissa, Dr Anderson who was out the same morning on another boat, estimated that no less than 17 individuals were feeding in an area of 5 kilometers square. All of this seems to suggest that the Blue Whales which had arrived in the Bay of Bengal from November to January were now leaving it, emptying out of the seas off Trincomalee and being seen off Mirissa as they journeyed back to the Arabian Sea. The tail end of the 2010/2011 season once again seemed to suggest that beyond April, Blue Whales would not be present in sufficiently large numbers for commercial whale watching to be feasible.

No one had tested this although it has been known for decades that some Blue Whales were present throughout the year. This was clearly demonstrated in reviews from the 1980s and in a regional study of strandings by Charles Anderson and colleagues published in 1999. Anouk Ilangakoon, at a marine mammal conference in the Maldives in July 2009 had presented a paper re-iterating the presence of Blue Whales throughout the year.

In my dialogue with Dr. Anderson, he suggested that Blue Whales may adopt two feeding strategies: those which took part in the East-West migration and those that chose to stay around Sri Lankan waters. I wrote about this in an article published in the Sunday Times on 26th December 2010. I had a conversation in June 2011 with Lester Perera who had researched cetaceans for the National Aquatics Resources Agency (NARA) in the 1980s. He was also adamant that he had recorded Blue Whales throughout the year but was not sure why there were no recent records in the May to August period. There was speculation from several people that the fighting had scared them away.  I was convinced that I needed to go out myself during the “off season” to have a look. Maybe the whales are only not there because no one is looking for them. Ideally, I would need at least 10 trips to gain a sense of what is out there. But two nights at the Chaaya Blue Hotel organized by Nadija Tambia of John Keells gave me the chance for an exploratory ‘out of the whale watching season’ trip.

The stars had begun to fade from the brightening sky as we eventually heaved the boat from land onto the sea. The naturalists had warned me that the chances of seeing a Blue Whale are small at this time of year. I had been a strong advocate of this theory, but since last evening I had begun to suspect that those of us who had promoted commercial whale watching may have missed a trick. Soon after my arrival at the Chaaya Blue, Mohan and Gayan gave me print out of the Blue Whale sightings between 27th April 2010 and 14th November 2010. Most of the data I was shown  had been logged on trips by the regular Chaaya Blue Naturalist B. Dayarathne, who had joined me on my earlier unsuccessful trip.

Between 27th April 2010 and 14th November 2010, there was data on 41 trips and Blue Whales had been seen 14 times. This is a strike rate of 1 in 3 trips. On 28th April 2010, 6 Blue Whales had been seen on a trip led by naturalist Nilantha Kodituwakku.  After that the records are mainly singles, or pairs with one occasion where three had been seen. An additional data point on 18th November refers to un-confirmed sightings by fishermen of many whales continuously 35-40km east of Swamy Rock (but I suspect the distance is closer as fishermen rarely go beyond sight of land).

The data and the naturalists confirmed that as with Mirissa, during the December-April whale watching season, there is a marked increase in the number and ease with which whales are seen. Speaking to Chitral Jayatilake I gathered that between their first trip on the 21st February, up to 11th April, they had sighting on all but four days. Then it began to thin out. From Mirissa, outside of this season, the seas can be quite rough because of the South-west Monsoon and hardly any whale watching is undertaken. So even if a resident population of Blue Whales remains off Mirissa, it would be difficult to collect data. In Trincomalee on the other hand, boats can go out during the South-west Monsoon (although the winds can create choppy seas) and there is a chance of seeing the resident Blue Whales.

When I arrived in Trincomalee on 5th August, the hotels were not actively promoting whale watching in the May to August period.  The prevailing view was that a commercially feasible strike rate for seeing Blue Whales was not available. Studying the available data at the Chaaya Blue, I sensed that commercial whale watching may be possible. After all, when I headed South of Mirissa on 1st April 2008, no one had presented publicly a credible set of data to make a convincing case for the ease of seeing Blue Whales in the South. Perhaps as in Mirissa, the Blue Whales were not there only because a concerted effort had not been made to look for them.

The previous evening I had watched a shimmering thread of amber beads stretched out across the ocean’s horizon. These were fishing boats. I counted. There were 69 of them. If there were enough fish for so many boats, there must be a big enough food chain to support whales. I was filled with hope. I had heard reports that the boat used by the Navy was a large powerful vessel which headed out to 30-40 nautical miles to locate Blue Whales. I could not think of a clear reason for going out so far. I decided to go with my instincts and to search for Blue Whales where the fishing boats were. This also tallied with the cluster of sightings on the map in the naturalist’s room.

On the 1st of April 2008, a trip off Mirissa set the “Sri Lanka Best for Blue” story in motion. On 5th August 2011, off Trincomalee, I saw my first Blue Whale in the so called off season for whale watching. This has acted as a catalyst to collate data which points to an extension of Sri Lanka’s Blue Whale watching season. Close to N 08 34 441, E 81 21 176, where we encountered the whale, I texted the Jetwing Eco Holidays operations team and the naturalists to alert them. I followed up with a phone call whilst on the boat to Chitral Jayatilake to discuss the sighting. He thought the navy which had commenced a whale watching operation, may be a source of current data as the large boat used by them could go out safely in conditions which were too rough for the smaller boats used off the Nilaveli Beach. I also phoned Lester Perera on the drive back to Colombo. There were so many questions to be resolved. Are those Blue Whales which are seen at this time of the year, permanent residents or do some alternate between participating in the East –West migration and staying back in some years? If an individual whale adopts a mixed feeding strategy, is this related to a particular developmental stage? Do any whales come in from the East? Only radio tracking and photographic identification over a long term will answer these questions. I had been told of a sighting of a Blue Whale in Mirissa which had a radio transmitter embedded. Where had that whale come from?

A more immediate question was whether we could claim a viable whale watching product off Trincomalee between May and August. Lester had whale watched on 19th July, embarking off Nilaveli Beach and not seen Blue Whales. He had failed. Had I just got lucky on the day or were there enough Blue Whales out there for a mainstream tourism product? The data so far was too sparse. I needed the Navy data.

More data arrived soon. On Saturday 13th August I was at Talangama Wetland with Riaz Cader when Suchithra phoned him to say he had scanned the sea from Swamy Rock. He had made it a point to carry binoculars because he had been inspired by John Keells naturalist Nilantha Kodituwakku’s photograph of a Blue Whale near Swamy Rock. Suchithra had seen a single Blue Whale. I sighed aloud that I needed the Navy data. If the Blue Whales were so close, why was the Navy going so far out? What was the strike rate of the Navy? Exactly a week later, an excited Jetwing Eco Holidays naturalist Wicky Wickremesekera came home and told me excitedly that Supurna had also seen Blue Whales off Trincomalee. On Wednesday 17th August Supurna had also scanned the sea from Swamy Rock through his binoculars. A few kilometers out, he could make out three simultaneous blows of Blue Whales. I had over coffee at Cinnamon Grand a few days earlier, told him of my sighting and my view that Blue Whales may be off-season only because we are not looking for them. I told him of the view held by Anouk Ilangakoon and Lester Perera. Inspired by this, he chartered the same boat he had taken with me a year ago and set out on Thursday 18th August. At 9.15am he had three Blue Whales in the field of view, an estimated 5-6 kilometers from the shore. The sea turned rough and on the way in, they had another Blue Whale close to Swamy Rock. It seemed like to see Blue Whales all one had to do was spend time on Swamy Rock. I wondered again why the navy was sailing two hours out to sea and what their strike rate may be.

Sandie Dawe the CEO of Visit Britain who was touring Sri Lanka alerted me to a group she had met who had seen whales the previous day with the boat operated by the Sri Lankan Navy. Paramie Perera from the Jetwing Eco Holidays team traced the guide as Ananda Perera from Jetwing Travels. He gave me a first hand account of spending two hours at sea before encountering Blue Whales. They had several sightings; at one time they had three in the field of view on Wednesday 10th August. As I began to ask around for more first hand accounts, I spoke to another person who had been on the Navy boat on Saturday 13th August. He could see five Blue Whales spouting at one time and the Navy personnel had said there were six Blue Whales out there.

I had by now accumulated a fairly convincing collection of data but the Navy data was essential. Fortunately for me Riaz Cader who heard me sigh about needing the Navy data did some nifty footwork and reached Commander Kosala Wijesooriya who is in charge of the whale watching operation. “The Navy wants to talk to you’ he said sounding ominous. The Sri Lankan military now has a new breed of officers who are tech savvy and results oriented. A flurry of emails and text messages followed leaving me impressed at the speed and quality of the response. On Saturday 20th August I spoke to Commander Kosala Wijesooriya, the project manager for the Navy’s whale watching operation. They had been running the whale watching on Wednesdays and Saturdays starting from 11th June 2011. He was on his 13th trip. He was on the boat on the Navy’s 15th whale watching trip. They had seen Blue Whales on 13 out of 15 trips, a strike rate of over 80 per cent. Furthermore, he confirmed that the whales are only 6 to 8 nautical miles east of Pigeon Island. The two hour trip to get there was because they took a longer route to find dolphins. His distance tied in with what I had expected and the on-shore and at sea observations. As Sri Lankan Navy A543 approached the Trincomalee Harbour, with Commander Kosala Wijesooriya on the phone to me, I knew the story was in the bag. I now had accumulated enough data from first hand observations to take the story to the market that there are enough Blue Whales present off Trincomalee between May to August, during what had been perceived as “off season” for Blue Whales.  This article represents the first effort to compile observations to make a credible story backed by data to take the story to press and tour operators locally and overseas, that commercial Blue Whale watching is possible from Trincomalee from around late February/March when the seas become calm  and through to August. During December to late February, the seas may be rough off Trincomalee and Mirissa may be a better option. As the Mirissa season starts in November/December, Sri Lanka now offers between 9 to 10 months of Blue Whale watching.

But information based on a phone conversation is not available for independent, external scrutiny. No one so far had made an extensive data set available on-line. Would the Sri Lanka Navy be able to do it? At least the date, time, species and number of whales seen? Asking for the GPS locations may be pushing my luck. Or at least, can I take a look at the Navy log? Commander Wijesooriya hesitated. Releasing data would need clearance. I said it would be crucial as eco-tourism relies on credible data in the public domain for people like me to win the buy in of the media, clients and the tourism industry. Making their data public would fill hotel rooms and create employment.  There was a pause at the other end of the line. “If it is going to help promote tourism in Sri Lanka, the Navy will help you” he said hanging up as the A543 made its final approach to the harbor.

On Thursday 25th August, Commander Wijesooriya called me. The whale watching data from both Galle and Trincomalee, including GPS points was on-line on http://whalewatching.navy.lk. Wow! With my wife Nirma and children Maya and Amali, I accessed the Navy’s website and downloaded the pdfs. My children were surprised at my excitement. I told them that in years to come there will be 20-30 regulated and responsible whale watching boats off Trincomalee generating millions of rupees a day. It would be a much needed focus for the East Coast besides the beaches. Tourists now could see The Gathering of Elephants listed by Lonely Planet as one of the Top Ten spectacles in the world and go on to Trincomalee to watch Blue Whales by boat or if lucky from atop Swamy Rock with the use of binoculars. However, a review of the data and further conversations revealed that the navy had not distinguished between Blue and Sperm Whales. So it is possible that the navy’s strike rate for Blue Whales may have been less than the 13 out of 15 or 87 per cent it had seemed at first. As the log did not refer to large groups of whales (typical of Sperm Whales), probably most of the sightings were just Blue Whales. Even if the strike rate were to drop for Blue Whales, if for Blue or Sperm Whales, there is a blended strike rate of over eighty per cent during June to August. That is good enough for mainstream tourism to offer whale watching from Trincomalee from March through to August.

On Monday 29th August, I met Commander Wijesooriya with Riaz Cader and Ganganath Weerasinghe at Cinnamon Grand’s pool-side cafe to pore over the admiralty charts with the navy data. Although Commander Wijesooriya had served in and around Trincomalee on Dvoras and other navy boats from mid 1997 to May 2011, he had never seen a Blue Whale. He was then pre-occupied with looking out for attacks from LTTE suicide boats. It was a classic case of what I had told on camera the previous Friday to ETV, that what you see is what you look for. There were only scattered, hazy anecdotal accounts of the navy encountering whales as they fought a sophisticated enemy in the sea. I was impressed to hear that the navy had the foresight to trail blaze whale watching in what was perceived as the off season for Blue Whales. They took a gamble with no concrete data to suggest that they will find whales. Now the tourism industry needs to realize that the Blue Whales off Trincomalee are the East Coast’s biggest international draw, beside its beaches.

As we talked with Wijesooriya, Libby Own-Edmunds joined us as and I learnt that she had seen a Blue Whale on the 6th May 2011. A few minutes later naturalist B. Dayarathne informed me that their boatman had encountered Blue Whales about 5 kilometers away from Pigeon Island on the 26th August. Data continues to roll in. Several days later, Eshan Goonesekera showed me images of Blue Whales he had taken on 16th August 2011. He had chartered a boat from Pigeon Island Resort and seen two Blue Whales after an hour.
On the 24th August at the Barefoot Cafe, I met some people who told me that a few weeks earlier their friends had been discouraged by their hotel in Trincomalee from going out to sea for Blue Whales. They had been told it was the wrong time for whales. All that will change now.


De Silva Wijeyeratne, G. (2011). Longest and Best for Blue. The Sunday Times Plus. Sunday 04 September 2011.
The first article using a compilation of data to make the case that Blue Whales (and Sperm Whales) present off Trincomalee extend Sri Lanka’s commercial Blue Whale watching season to span from December to August.
http://sundaytimes.lk/110904/Plus/plus_08.html we have come to sing today  sing you blues and cares away