“This is not basic needs. This is really beyond that,” said Glaudy Perdanahardja, an official with The Nature Conservancy, which is based in the United States but has an office in Indonesia that focuses on the Savu Sea. He suggested that islanders were no longer hunting merely for subsistence, but also for commercial purposes.

Although the group acknowledges the importance of whaling to the community, it worries that the introduction of motorboats to Lamalera more than a decade ago has led to the killing of more marine life. Nowadays, Lamalerans use motorboats to hunt dolphins, mantas and pilot whales, rather than traditional sailboats. While they still use sailboats to harpoon sperm whales, they sometimes use motorboats to tow the sailboats to the whales to speed up the chase.

“Now they can go farther and catch things they could not originally catch,” said Yusuf Fajariyanto of the conservancy, who visited Lamalera in 2015 to observe the hunting practices.

But Lamalerans bristle at efforts by outsiders to regulate their fishing practices. “The sea is our mother,” said Aloisius Gnneser Tapoona, 63, a grizzled harpooner who said he had killed around 80 sperm whales in four decades of hunting. “Those who would restrict our access to the sea are those who would kill our mother.”