More than 350 scientists and conservationists from 40 countries have signed a letter calling for global action to protect whales, dolphins and porpoises from extinction.

They say more than half of all species are of conservation concern, with two on the “knife-edge” of extinction.

Lack of action over polluted and over-exploited seas means that many will be declared extinct within our lifetimes, the letter says.

Even large iconic whales are not safe, such as the blue whale.

“Let this be a historic moment when realising that whales are in danger sparks a powerful wave of action from everyone: regulators, scientists, politicians and the public to save our oceans,” said Mark Simmonds.

The visiting research fellow at the University of Bristol, UK, and senior marine scientist with Humane Society International, has coordinated the letter, which has been signed by experts across the world.

Growing threats

“Save the whales” was a familiar green slogan in the 1970s and 1980s, part of a movement that helped bring an end to commercial whaling.

While stricken populations in most parts of the world have had a chance to recover from organised hunting, they are now facing myriad threats from human actions, including plastic pollution, loss of habitat and prey, climate change and collisions with ships.

By far the biggest threat is becoming accidently captured in fishing equipment and nets, which kills an estimated 300,000 whales, dolphins and porpoises a year.

Hundreds of scientists have expressed the same concern – that we are moving closer to a number of preventable extinctions. And unless we act now, future generations will be denied the chance to experience these intelligent social and inspiring creatures.

They point to the decline of the North Atlantic right whale, of which only a few hundred individuals remain, and the vaquita, a porpoise found in the Gulf of California, which may be down to the last 10 of its kind.

And they say it is almost inevitable that these two species will follow the Chinese river dolphin down the path to extinction. The dolphin, also known as the baiji, was once a common sight in the Yangtze River but is now thought to have died out.

The letter, which has been signed by experts in the UK, US, Mexico, South Africa and Brazil, among others, points out that these “dramatic” declines could have been avoided, but that the political will has been lacking.

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