A collaboration of coast and countryside organisations on The Lizard Peninsula

2019 was a year of achievements for Cornwall Wildlife Trust’s (CWT) Marine Strandings Network (MSN); Our annual MSN conference attended by the highest number of people since its establishment in 2004, a new What’s App system was formed to communicate with volunteers which has revolutionised the way we deal with stranding reports making the process infinitely easier and smoother, and finally the Trust started work with Defra and CEFAS on SW cetacean bycatch pilot project which aims to gather bycatch evidence and trial mitigation devices with local fishermen. But it was also a year of continued sadness as a shocking number of marine animals continued to strand around our coastline.
Records of stranded marine organisms have been collected in Cornwall and the Isles of Scilly for many years, the earliest record being logged from 1354. To date, the Cornwall Wildlife Trust Marine Strandings Network (CWT MSN) database holds over 9,000 records, comprising data relating to stranded cetaceans (whales, dolphins and porpoises), seals, turtles, birds, cephalopods, fish (including sharks), seeds, hydrozoa, molluscs, echinoderms and crustaceans.

Castle beach: Common dolphin, photo by CWT MSN]Castle beach: Common dolphin, photo by CWT MSN

In 2019, 247 cetaceans (dolphins, porpoises and whales) stranded - the second highest figure in 15 years (the highest being 250 in 2017). These carcasses reported to CWT MSN are either examined in-situ by trained volunteers, or via post-mortem examination by a veterinary pathologist affiliated to the University of Exeter (UofE) Cornwall Campus. Of the 247 cetaceans which stranded in 2019, 33 were sent for post mortem, and a quarter of these were found to have the cause of death as bycatch.

In addition to studying the animal by post mortem, we can also gather invaluable information on the cause of death from bycatch by looking at certain external injuries on the beach for all species, not just those that undergo post mortem examination. Rissos calf in Mounts Bay 5th May_2019_Marine_Discovery

Rissos calf floating in sea off Mounts Bay

To do this the MSN developed a tool called the Bycatch Evidence Evaluation Protocol (BEEP), where detailed photographs of the carcasses are taken and assessed to identify and record signature injuries and features identified as being associated with bycatch and entanglement in fishing gear. This protocol has been developed from 25 years of experience and is continuously tested and developed to improve the accuracy of bycatch detection. Of all 247 cetaceans which stranded in 2019, 43% were assessed on the beach by BEEP which identified that nearly a third of the animals were defined as cause of death by bycatch.

As well as highlighting conservation concerns which require actions, such as bycatch, monitoring strandings can also tell us about changes in the sea. For instance, in the past 4 years (2016 – 2019), we have seen a significant rise in common dolphin strandings compared with other species, potentially demonstrating an increase in common dolphin numbers living around our coast. We are also seeing more Risso’s dolphins strand, including a dead calf found out at sea in Mounts Bay in May 2019, which reflects the fact that we are seeing more live Risso’s dolphins living in our coastal waters throughout the year.
Stranded Grey Seal photo CWT MSN

Stranded Grey Seal photo CWT MSN

But perhaps the most shocking change we are seeing is the increase in seal standings. In 2019, MSN recorded an alarming 246 dead seals around Cornwall. To give you an idea of the volume, let me provide you with the data from the previous 10 years – 61 in 2009, 87 in 2010, and even 197 in 2018 (which was the second highest year). Frequently, the spike in strandings are associated with stormy weather systems hitting our coastlines during the autumn and winter months, coinciding with the Atlantic Grey Seals breeding seasons and in turn impacting on the pups and young seals that are ill equipped to deal with the battering the storms can give them. With our climate changing, we are in no doubt that these storm events will continue and even increase, and that proves a worrying future for these special creatures.
I could go on for pages about what the data we collect tells us about these incredible animals and the sea within which they live, but it important to finish with is the fact that we must continue with this research. And you can help – by reporting any dead marine animal you find along our coastline when out and about. The CWT MSN has a dedicated Strandings Hotline telephone number (0345 201 2626), for the reporting of stranded marine animals. The Hotline number operates year-round and is staffed by a rota of dedicated volunteer Hotline Coordinators. So please, save it in your phone and be part of the Project, and attend our annual Forum on the 21st March at Truro College to find out more, booking via Eventbrite here https://msnforum2020.eventbrite.com/. Let us see together what 2020 brings.

Published: Feb 2020 
Author:  Abby Crosby, Marine Conservation Officer, Cornwall Wildlife Trust