The report, summarising the work of the vital marine conservation project in Cornwall and available to download from the trust’s website, has highlighted an astounding 50% increase in cetacean deaths in 2016, compared with 2015.
A total of 205 animals stranded in Cornwall in 2016, compared with only ten in 2015. Among the 205 recorded, 113 were short-beaked common dolphins and 61 were harbour porpoises. Of particular stranding interest in 2016 were both a female sperm whale, which stranded and was post-mortem on Perran Sands in July 2016, and a bottlenose dolphin, which stranded on the Isles of Scilly and was recorded in November 2016.
A minke whale also stranded further north at Compass Point, near Bude, on July 13, 2016.
Abby Crosby, marine conservation officer at Cornwall Wildlife Trust, said: “The Trust has been collecting data on marine mammal strandings for over 25 years, so we can clearly identify peak levels of strandings. Seeing this recent increase is extremely worrying and highlights the importance of ensuring this work continues into the future whilst we discover what is happening out at sea.”
Animals strand for a variety of reasons, from natural causes such as disease, to bycatch and boat strike. Of the 205 that stranded during 2016, 31 were accessible and suitable for retrieval by the trust’s MSN team for post-mortem examination on behalf of the Defra-funded Cetacean Strandings Investigation Programme (CSIP).
Post-mortem examinations, together with in situ examinations, concluded that accidental entanglement in fishing gear — also known as bycatch — was the cause of death for 28% of the animals.
Of further interest, the cause of death of 16% of the animals examined was bottlenose dolphin attack, where smaller animals are attacked by larger bottlenose dolphins. One such incident was witnessed by members of the public in Mounts Bay in January last year, with the carcass stranding soon after the event.
Abby added: “2016 was a busy year, but 2017 is proving just as challenging, if not worse, with over 200 dolphins being recorded to date to our 24-hour Marine Strandings hotline. If we have another bad winter, we will easily overtake the 2016 total, which is a worry to all biologists conserving these special creatures in our waters.”
Data is used not only regionally, but shared nationally to the Cetacean Strandings Investigation Programme, to better understand the ecology of dolphins, porpoises and whales in the UK waters, so their management and protection can be worked towards.
The Trust is calling the public to send in their sightings of any stranded, dead marine animals to their hotline, 0345 201 226. For more information, visit www.cornwallwildlifetrust.org.uk/strandings and download the 2016 MSN report.