Right whales, which can grow to 68ft and weigh 70 tons, are being wiped out by collisions with ships and entanglement in ropes and nets

A slaughter begun 400 years ago by British and other European whaling ships may soon reach its catastrophic end with the extinction of a species.

A survey has found that fewer than 100 female north Atlantic right whales of breeding age survive. They may not be able to produce enough calves for the species to recover.

The animals, which grow to 68ft and can weigh 70 tons, are no longer hunted but are being wiped out by collisions with ships and entanglement in shipping gear, according to research by Michael Moore of the Woods Hole Oceanographic Institute, on America’s east coast.

The whale got its name because it was the “right” whale to hunt: it moved slowly and helped its human predators by floating after