porpoise

They also reminded people that dolphins, whales and porpoises are protected by law.

The goal now is to stop the Yangtze finless river porpoise - 1,200 of which remain in the wild, according to current estimates – from suffering the same fate.

The number of whales, dolphins and porpoises getting into difficulty has risen from about 100 a year to more than 300 over a 30-year period.

It is unclear why dolphins attack porpoises but experts say it could be an aggressive response to feeding competition or misdirected sexual aggression.

Within the wider marine environment at this time of year there are breeding seals and harbour porpoises.