Nearly 5,000 whales and dolphins left stranded

Nearly 5,000 harbour porpoises, dolphins and whales have been left stranded on UK shores in the last decade, a study has revealed.

The government said 4,896 cetaceans were reported washed up between January 1 2011 and December 31 2017.

The findings are part of a seven-year review published by the government and led by the international conservation charity ZSL (the Zoological Society of London).

Researchers recorded 21 different cetacean species – nearly one quarter of the total currently known to science – as well as six species of marine turtle and several species of large bodied sharks.

The highest number of strandings in a single year was also recorded in 2017, with more than 1,000 noted.

The team also investigated several large-scale mass stranding events involving multiple animals, including one in July 2011, in the Kyle of Durness where 70 long-finned pilot whales stranded together.

They also conducted 1,030 post-mortem examinations to identify why individual animals had died.

Infectious disease and incidental entanglement in fishing gear were two of the most common findings.

Bycatch accounted for 23% of common dolphin deaths and 14% of harbour porpoise deaths.

Others caused directly by humans included 25 animals killed by ship-strike and a single Cuvier’s beaked whale that suffered a gastric impaction following the ingestion of marine litter in 2015.

Cetologist Rob Deaville, who led the study, said: “It’s difficult to say conclusively what’s driven this rise, but it’s potentially associated with multiple causes – including increases in local reporting effort and seasonal variation in the population density of some species.

“As both nets and propellers can cause characteristic injuries, we can readily diagnose causes of death which are directly related to human activity, such as bycatch and ship-strike.

Picture: Kim Cessford. A whale discovered in North Queensferry.