Sperm whale (Physeter catodon)

Sperm whale (Physeter catodon)

The world’s whale watchers, naturalists and scientists are discovering what an incredible place Sri Lanka is to observe whales and dolphins. Large pods of whales are regularly observed close to the Sri Lankan coast with major hot spots off the southern tip near Mirissa and in the north-east near Trincomalee.

A blue whale traveling along the shipping line - ship strikes and propeller noise can cause stress.

A blue whale traveling along the shipping line. Ship strikes and propeller noise can cause stress and lethal injuries.

However, these animals are adversely affected by ship strikes from the busy international shipping lanes which run through their feeding grounds, harassment from currently unregulated whale watching operators, and entanglement from ghost fishing gear. At present, international NGO, Friend of the Sea is recommending shifting the shipping routes in order to minimize the number of whale collisions in Sri Lanka’s southern oceans. It is estimated that 50-100 whale deaths are caused by ship strikes each year and moving the lanes a mere 15 nautical miles south of their present position will allow ships to bypass the most populated area.

This boat got too close to the blue whale: for the well being and safety of both animal and viewers, it is best to maintain a distance of at least 100m.

For the well being and safety of both whales and viewers, it is best to maintain a distance of at least 100m.

In order to understand and protect these mammals, it is essential to first map out the spatial and temporal distribution of the species present. Dedicated cetacean surveys around the island have been extremely limited due to a lack of resources. Vessel surveys provide some data on cetacean occurrence off the east coast and west coast but for the south coast the only available data at present is from opportunistic observations over the years. Most of the information known about cetaceans off southern Sri Lanka at present is from sporadic strandings along the coastline and studies on fisheries by catch and direct take of cetaceans.

Dolphin caught in a fishing line

Dolphins get entangled in fishing nets and suffocate when unable to surface for air.

Satellite tracking is currently the best and least disturbing way to assess movement and behaviour of animals, such as whales, that have a long lifespan and potentially cover vast distances. Non-contact observational methods are financially and logistically costly. These cause more disturbance to the animals through repetitive boat noise and presence than the one time deployment of a single tag that will provide detailed information over an annual cycle. The satellite tracking technology can be used to determine seasonal/annual movement, the degree of site residency, and potential migratory activity of blue whales in the northern Indian Ocean. The high number of encounters and sightings in Sri Lankan waters throughout the year suggests the region supports a relatively large population of this globally threatened species.

A propeller strike left this blue whale with a notch in it's back, but it is estimated that ship strikes kill 50-100 whales annually.

A propeller strike left this blue whale with a notch in it’s back, but it is estimated that ship strikes kill 50-100 whales annually.

Sri Lanka provides nature lovers the opportunity to see these graceful and gentle giants and efforts should be taken by all vested parties to protect them and their habitat. Visitors can contribute towards the continued well being of our marine mammals by seeking and supporting whale watching tour operators who abide by best practices to ensure the safety and comfort of both viewers and animals. Some simple guidelines include not getting closer than 100m (200m if another boat is present), not dumping any waste or contaminants in the water, never going head on towards or following after animals, and paying special care near mothers and young.

Whale watching seasons:
October-April
Mirissa in the south-west
Kalpitiya in the north-west

December-April
Trincomalee to the north-east

Some of the species likely to be spotted:
Blue whale; sperm whale, Bryde’s whale, Orca (killer whale) and beaked whale, spinner dolphin, spotted dolphin, bottlenose dolphin, Risso’s dolphin and Fraser’s dolphin