Increasing traffic in the waters of Sri Lanka threatens blue whales
Large numbers of animals have been killed by collisions with boats and propellers. Scientists fear that cetacean watching tourism is the cause...
In early April, whale watchers off the southern coast of Sri Lanka had a disturbing vision: the lifeless body of a blue whale 60 feet long floating in the water about 20 miles offshore.
The body was quickly becoming swollen and there were fish-louse sucking all the animal's skin. Even more disturbing was the condition of the tail which had been almost completely severed from the body.
"It was very clear it was caused by the propeller of a boat," said Mazdak Radjainia, structural biologist and underwater photographer, University of Auckland, New Zealand, who found the whale by chance. "It must have been a very cruel death, because the damage was enormous."
Researchers say the clashes with boats are a major cause of death among whales. Many of those killed belong to endangered populations, such as blue whales, which are barely managing to be maintained.
The issue is particularly problematic in Sri Lanka, where a large population of blue whales have not been studied, whose number, possibly in the thousands, has faced increasing pressure from commercial shipping and an explosion of whale watching boats is not regulated.
As these waters are not properly controlled, scientists are not sure if the incidents with boats are increasing. But the death of the whale in April has been the sixth year, according to news reports. In a terrible incident that occurred in March, a blue whale was found shaking over the bow of a container ship in the port of Colombo, 145 miles north of this seaside resort.
Last year, about 20 whale carcasses (not all blue whales) were seen around the island, according to Arjan Rajasuriya, research officer of the National Aquatic Resources Research and Development Agency in Colombo. It is not known how many of the deaths resulted from collisions with boats.
"These incidents probably represent only a portion of the probable actual mortality," said John Calambokidis, a whale researcher from Olympia, Washington, documenting collisions with boats on the west coast of the United States. As blue whales often sink soon after they collide, the majority of these deaths are not recorded, and Calambokidis says the true number "can be 10 or 20 times" greater than the perceived.
Twenty-five kilometers from the southern coast of Sri Lanka is one of the busiest transportation corridors in the world, and whales are known to regularly swim in them. But some scientists believe the increase in whale watching may be forcing the animals to go further to look for food, pushing them to the route of large ships.
"I fear that whales are being disturbed by watching boats and that it may be affecting their movement," said Asha de Vos, whale researcher in the country.
The threat suffered by whales led some researchers to strive to learn as much as they can about them, in order to find a way to protect them.
"Having these whales close to the coast is something impressive," said the scientist, Ari S. Friedlaender, a researcher at Duke University Marine Laboratory. "We know so little about blue whales in general that wherever we have easy access to these animals increases the learning curve exponentially."
In 2009, Sri Lanka ended a bitter civil war of 25 years, which largely kept foreign scientists and researchers away from their waters. Several surveys of the 1970s revealed general nature of the presence of whales, but interest began to grow only in the 1990s. The researchers were particularly attracted by the fact that whales tend to stay in the region throughout the year. It is known that other populations of blue whales migrate over long distances.
Perhaps no one has studied these whales and promoted the preservation of them more than de Vos.
Three years ago, de Vos started the Blue Whale Project of Sri Lanka, a program of long-term research that she hopes will stop the carnage and sensitize people about local whales. Over the past three years, from December to May, she photographed the whales and used scientific instruments to better understand their eating behaviors.
"There is definitely something down there that is causing them to become closer to shore. But we need to know where it is and the amount we are talking about," she said.
In March, de Vos was aided by a team of researchers from Duke University Marine Laboratory. The group brought forth an electronic echo sounder, which uses sound waves to measure the density of prey in the water. During 10 days, she and her team traveled miles inland, taking measurements and finding points of highest density of krill.
The data will help scientists better understand when and where the whales feed - and de Vos hopes to persuade the government to change the shipping lanes farther offshore.
De Vos, who was born and raised in Columbo, Sri Lanka, became an advocate of blue whales after taking a boat ride in 2006 and being impressed by what she saw.
"There were six whales in an area of four square kilometers from where I was, and that was enough for me," she said. "That was a sign. I realized that I wanted to better understand them and protect them."
However, her initiative is full of challenges, including lack of support from local authorities and the disadvantages of being a young woman in a male-dominated society.-
"I am very lonely here," she said. "I have a lot of infrastructure or equipment to do my job."
She received some financial support from the University of Western Australia, where she is completing a doctorate in oceanography.
"The work of Asha de Vos is in fact preparing the ground for future research on these animals," said Friedlaender, who hopes to visit the region next year.
De Vos notes that since the civil war in Sri Lanka, there is currently a major effort to enhance tourism and whale watching is a fundamental part of the development strategy of the government. While this effort may bring much needed economic development for this poor country, de Vos is concerned with the possibility that everything is happening too fast.
"At the moment, the whale watching boats are being conducted in a disorderly manner close to the animals," she said. "I do not want it to be spread in a way that it becomes a disturbance to the whales."
In other countries with established whale watching industries, laws prohibiting getting too close to the animals, in the United States, for example, define a minimum distance of 90 meters. De Vos wishes there were similar regulations in Sri Lanka.
"In this new era of peace, the blue whale is very quickly becoming the symbol of our country," she said. "It would be very sad to harm these animals because of our foolishness.
Translated from the Portguese version by: