Dominica protects its sperm whales – and the climate

The tiny Caribbean island of Dominica has created the world’s first marine protected area for its sperm whales, which can grow up to 15 metres and have the largest brain in the world. 

The reserve will protect nearly 800 square kilometres of ocean on the western side of the island nation that serve as key nursing and feeding grounds. 

“We want to ensure these majestic and highly intelligent animals are safe from harm and continue keeping our waters and our climate healthy,” said Dominica Prime Minister Roosevelt Skerrit.

The reserve will allow sustainable artisanal fishing and delineate an international shipping lane to avoid more deaths of sperm whales. An officer and observers will ensure the area is respected and that whale tourism regulations are enforced. Visitors can still swim with sperm whales and see them from a boat, but in limited numbers.

Scientists say the reserve will also help fight climate change, because sperm whales defecate near the surface. Their nutrient-rich excrement creates plankton blooms on the ocean surface. They capture CO2 in the atmosphere and drag it to the ocean floor when they die. 

Sperm whales in Dominica are believed to defecate more than whales elsewhere, said Shane Gero, a whale biologist and founder of the Dominica Sperm Whale Project, a research program focused on sperm whales in the eastern Caribbean.

The project has spent thousands of hours observing sperm whale families, getting to know them as individuals within families. It has followed sperm whale families of whales across years, showing that some families have been using the region for decades. The detailed behavioural histories of these individuals are rare among mammals, particularly in the ocean, it says.

Less than 500 sperm whales are estimated to live in the waters around Dominica, part of a population that moves along the Lesser Antilles chain, swimming as far south as St. Vincent and north into Guadeloupe. Unlike sperm whales elsewhere in the world, the ones around the eastern Caribbean don’t travel very far, Gero said.

Sperm whales are a matrilineal society, with young males leaving and switching oceans at some point in their lives. As a result, protecting the species is key, especially if few female calves are born, he said. “One calf being entangled can mean the end of a family,” he said. Sperm whales can produce a single calf every five to seven years.

An estimated two million sperm whales roamed the Earth’s deep waters before they were hunted for oil used to burn lamps and lubricate machinery. Now, some 800,000 are left, Gero said.

Images: All these glorious images come from the Dominica Sperm Whale Project’s website.

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