Dominica set to open world’s first reserve centered around sperm whales

The world’s first marine reserve for sperm whales is set to open in the waters off the coast of Dominica, a tiny island nation in the eastern Caribbean Sea. The reserve’s establishment is aimed at safeguarding a local population of a few hundred endangered sperm whales (Physeter macrocephalus) that are threatened by fishing gear entanglements, pollution, ship strikes, and even tourism.

The reserve, which was announced on Nov. 13, will span 788 square kilometers (304 square miles), an area about half the size of London. It will be situated along the west coast of Dominica, encompassing a critical feeding and nursing area for the whales.

The new reserve will cover just 3% of Dominica’s exclusive economic zone (EEZ) but will expand the nation’s total marine protection by 70%. Dominica currently has two other very small marine protected areas (MPAs), one of which is only 5 km² and the other 6 km² (1.9 mi² and 2.3 mi²).

“The 200 or so sperm whales that call our sea home are prized citizens of Dominica,” Roosevelt Skerrit, Dominica’s prime minister, said in a statement. “Their ancestors likely inhabited Dominica before humans arrived. We want to ensure these majestic and highly intelligent animals are safe from harm and continue keeping our waters and our climate healthy.”

Sperm whales are the largest animals in the toothed whale family. An average male grows to be about 15 meters (50 feet) long — about three times longer than a giraffe’s height — and can weigh up to 45 metric tons, about 90 times as heavy as a grand piano. The sperm whale also has the largest brain in the animal world, the organ weighing about 8 kilograms, or 18 pounds.

These marine mammals are also extraordinarily deep divers, plunging 1,000 to 2,000 m (3,300-6,600 ft) underwater to search for squid. During these deep dives, sperm whales can hold their breath for about 90 minutes.

Sperm whales also form strong family units, or clans, with each member communicating through the same “dialect” of click patterns. Whales within the same family may babysit for each other, and newborns may be nursed by their mothers as well as aunts, grandmothers, or other females within the clan.

Most of the sperm whales that inhabit the waters off the coast of Dominica are part of the Eastern Caribbean Clan, which currently has a population of fewer than 300 individuals, according to experts. Since 2010, the sperm whale population in this region has declined by about 3% each year due to human activities such as fishing gear entanglements, vessel strikes, and tourism pressure.

The newly formed reserve will help protect sperm whales by introducing strict rules for vessel traffic, including the use of designated corridors. The reserve will also regulate tourism activities like whale watching and swimming with whales.

“We want to ensure that with this legislation that there are clear protocols in place for how we approach the whales and how you leave the whales,” Francine Baron, CEO of the Climate Resilience Execution Agency for Dominica, a government agency, said in a press briefing on Nov. 14.

Traditional fishing, including the use of fish aggregating devices (FADs), wooden structures with hanging nets to attract fish, will still be allowed in the reserve. However, Baron said these fishing activities will not interfere with the sperm whales. She also said the vessel restrictions would make it less likely for FADs to be dislodged and entangle the whales.

Establishing the new sperm whale reserve may also reap benefits for the planet.

Enric Sala, founder of the Pristine Seas project and an explorer in residence at National Geographic, who advised the government of Dominica on the establishment of the reserve, says that when whales come to the surface between dives, they defecate nutrient-rich feces that encourage phytoplankton production. These microscopic plants absorb carbon dioxide and release oxygen, he explains.

“When this plankton dies, it sinks to the bottom of the ocean to the deep sea with a carbon in it,” Sala said at the same press briefing. “It then becomes a carbon sink. The more whales in the ocean, the more it will be able to help us mitigate climate change.”

Once the reserve is implemented, the Dominican government will appoint an official to closely monitor the reserve to ensure that the rules are being followed. Tourism will be allowed to continue, but in limited numbers.

“We have lived in harmony with the whales for several decades and consider them as part of us, and they have also formed an important component of our tourism product,” Baron said. “In our thrust to approach resilience in a holistic manner, we recognize the need to also ensure the resilience of our marine ecosystems, and in particular, to ensure the protection of the majestic sperm whales.”

Banner image: A sperm whale calf swims near the surface in waters off Dominica. Image by Brian Skerry/National Geographic-Pristine Seas.

Elizabeth Claire Alberts is a senior staff writer for Mongabay. Follow her on 𝕏 @ECAlberts.

Related audio from Mongabay’s podcast: A discussion of sperm whale culture, listen here:

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