Solomon Islands dolphin hunts cast spotlight on small cetacean survival

A new study on the impact of 'drive-hunting' dolphins in the Solomon Islands is casting a spotlight on the increasing vulnerability of small cetaceans around the world.

Drive-hunting in Solomon Islands [Credit: Oregon State University]

From 1976 to 2013, more than 15,000 dolphins were killed by villagers in Fanalei alone, where a single dolphin tooth can fetch the equivalent of 70 cents ($0.70 U.S.) -- an increase in value of five times just in the last decade.

Results of the Solomon Islands study are being reported this week online in the new journal, Royal Society Open Science.

"In the Solomon Islands, the hunting is as much about culture as economic value," said Scott Baker, associate director of the Marine Mammal Institute at Oregon State University and co-author on the study. "In other parts of the world, however, the targeting of dolphins and other small cetaceans appears to be increasing as coastal fishing stocks decline.

"The hunting of large whales is managed by the International Whaling Commission," added Baker, who works out of OSU's Hatfield Marine Science Center in Newport, Ore. "But there is no international or inter-governmental organization to set quotas or provide management advice for hunting small cetaceans. Unregulated and often undocumented exploitation pose a real threat to the survival of local populations in some regions of the world."

The drive-hunting of dolphins has a long history in the Solomon Islands, particularly at the island of Malaita, according to Marc Oremus, a biologist with the South Pacific Whale Research Consortium and lead author on the study. In 2010, the most active village, Fanalei, suspended hunting in exchange for financial compensation from an international non-governmental organization. The villagers resumed hunting in 2013.

"After the agreement broke down in 2013, a local newspaper reported that villagers had killed hundreds of dolphins in just a few months," Oremus said. "So we went to take a look."

Dolphin teeth are sold for necklaces [Credit: Oregon State University]

Oremus and co-author John Leqata, a research officer with the Ministry of Fisheries and Marine Resources, visited Fanalei in March of 2013 to document the impact on the population, and examine detailed records of the kills. During the first three months of that year, villagers killed more than 1,500 spotted dolphins, 159 spinner dolphins, and 15 bottlenose dolphins.

This is one of the largest documented hunts of dolphins in the world, rivaling even the more-industrialized hunting of dolphins in Japan, noted Baker, whose genetic identification research was featured in the Academy Award-winning documentary on dolphin exploitation, "The Cove."

"It is also troubling that teeth are increasing in cash value, apparently creating a commercial incentive for hunting dolphins," Baker said.

In drive-hunting, the hunters operate in close coordination from 20 to 30 traditional canoes. When dolphins are found, the hunters used rounded stones to create a clapping sound underwater. The hunters maneuver the canoes into a U-shape around the dolphins, using sound as an acoustic barrier to drive them toward shore where they are killed.

"The main objective of the hunt is to obtain dolphin teeth that are used in wedding ceremonies," Oremus said. "The teeth and meat are also sold for cash."

Oremus said the Solomon Island hunters understand the risk of exploiting the population.

"The government of the Solomon Islands has contributed substantially to research in recent years, but is not well-equipped to undertake the scale of research needed to estimate abundance and trends of the local dolphin population," Oremus said. "This problem exists in many island nations with large 'Exclusive Economic Zones.'"

Source: Oregon State University [May 07, 2015]