When the feeding grounds of blue whales overlap with busy shipping lanes, business interests often supersede those of the endangered marine mammals.
But in Sri Lanka, an unusual alliance has been forged: conservationists and shipping companies have aligned in a bid to move the heavily-trafficked lane about 28 kilometres (17 miles) away to help avoid collisions between whales and freighters. The only holdout is Sri Lanka, which has so far declined to sign off on the proposal, jeopardising the future thereof the biggest animal ever known to have lived on the planet, scientists say.
The hundreds of blue whales in Sri Lankan waters — marine biologists estimate there are 600 to 1,500 — feed on tiny shrimp in the shipping lane and are also believed to mate and give birth nearby. Shipping executives say they would gladly relocate the traffic corridor, recognising their ships would be safer in waters not already clogged with fishing vessels, whale-watching boats and the whales themselves, which can grow to more than 33 metres (100 feet), more than twice the length of a Tyrannosaurus Rex dinosaur.
Bryan Wood-Thomas, vice president of the World Shipping Council, said the group wrote to the Sri Lankan prime minister in 2017, affirming that all major international shipping organisations believed Sri Lanka should work with the United Nations to move its traffic lane.
"This is one of the few cases in the world where we can physically separate ships from where the whales are," Wood-Thomas said. "Yes, it adds a little distance, fuel and money to shipping costs, but the extra cost is really minor."
He said it was no small feat to get the majority of the world's shipping companies to agree to move the shipping lane in Sri Lanka.
"There are other places in the world where doing this would incur significant fuel costs or add a lot of time to the journey that businesses will not be happy to absorb," he said.
For a shipping lane to be moved, the country whose waters are most affected must submit a formal proposal to the International Maritime Organisation, the UN agency that regulates shipping. Despite numerous meetings between scientists, the shipping industry and UN officials during the past six years, Sri Lankan officials have demurred from supporting the shipping lane shift.
Rear Adm Rohana Perera of Sri Lanka's Marine Environment Protection Authority said the government is concerned about the economic impact of the proposed shipping lane move on its ports, fearing passing ships might not be as inclined to stop in Sri Lanka. He said a decision would "hopefully" be made in March.
The recent political turmoil in Sri Lanka has also complicated matters; a new government was only formed in late December after the president sacked the prime minister, prompting a constitutional crisis. Perera acknowledged Sri Lanka had other priorities at the moment but said they also recognised the importance of protecting blue whales.
"Conservation problems are usually so complex, but this one is very clear-cut," said Asha de Vos, executive director of Oceanswell, a Sri Lankan marine nonprofit. "This is a situation where Sri Lanka could really shine by taking the initiative."
In many parts of the world, there is no easy solution to the convergence of ships and cetaceans.
For example, scientists have long been worried about the sperm whales that live in the Straits of Gibraltar, but have few solutions.
"It's an incredibly busy area for shipping, but unfortunately, there's not much scope for moving the shipping lane because the straits are so narrow," said Russell Leaper, the scientific lead for blue whales at the International Fund for Animal Welfare, a conservation group.
Once hunted to the brink of extinction, the blue whale population has slowly begun to rebound since being granted protection from commercial whaling in 1946. Due to their size, the whales' only known predators are orcas and humans. Conservationists estimate there are between 5,000 and 15,000 blue whales globally and although their numbers are believed to be increasing, they are still classified as "endangered."
Scientists warn that blue whales in Sri Lanka are particularly vulnerable because they are the only population that doesn't migrate, making them especially susceptible to local threats such as ship strikes, Leaper said.
"It's a very unusual population because they're very isolated and they are in Sri Lanka all year around," he said. "Removing that one threat of ship strikes would make a very large contribution to saving them."
Although statistics on how many whales are killed by ships are patchy, some studies estimate dozens of blue whales are fatally struck by ships in Sri Lankan waters every year. Scientists say they believe that for every blue whale identified in a ship accident, up to 50 others go undetected, largely because once whales are struck and killed, they sink to the bottom of the ocean.
Michael Fischbach, executive director of the Great Whale Conservancy, said that protecting blue whales is crucial not just for the species, but for the planet. He explained that whales help stimulate the production of plankton, which in turn produces more oxygen to offset the impact of climate change.
"For the health of the oceans, we really need more whales," Fischbach said.