Protecting Cornwall’s seas – Cornwall Wildlife Trust’s marine review for 2019

2019 saw plenty of positive wildlife activity in Cornwall’s seas but there is much to be done to give marine life the best chance to thrive. Cornwall Wildlife Trust’s marine conservation team continue to work hard on various projects to record, educate on and campaign for marine life.

Whether it is inspiring the next generation of young people through the Your Shore Beach Rangers project, recording wildlife sightings as part of Shoresearch or Seasearch or influencing positive changes through government consultations and working with partners, it’s this dedicated team of staff, volunteers and local marine groups who are the eyes and ears on the ground (and in our waters).

Each year The Wildlife Trusts collates a marine review. This UK-wide review highlights the good and bad news for the marine life in our waters. To dive a little deeper, we have produced a Cornwall-specific marine review, which gives a picture of the current state of our seas.

Sand sifting starfish Matt Slater.JPG

The good news

8 Marine Conservation Zones designated around Cornwall as part of 41 new zones across UK

Back in May, the Government designated a third phase of 41 new Marine Conservation Zones (MCZs) around the UK, eight of which are around Cornwall, including the Camel and Helford Estuaries. MCZs are areas at sea where a range of rare and threatened species and habitats are protected from damaging activities.

Ruth Williams, Marine Conservation Manager at Cornwall Wildlife Trust, said at the time:

“This is fantastic news and a real reason to celebrate! Designating these additional eight sites as Marine Conservation Zones in Cornwall will help to guarantee a future for the extraordinarily diverse natural landscapes that exist beneath the waves off our coast, and help form the network of protected marine areas that we have been campaigning about for many years.”

“However, designation alone does not mean these sites will be protected and the next step is to ensure that these sites are effectively managed to aid recovery and a sustainable future for our seas.”

Grey Seal

Dave Thomas

Seal discovered commuting between Isle of Man and Cornwall

As reported in The Wildlife Trusts’ review, this year for the first time, an individual seal was discovered commuting between the Isle of Man and Cornwall. Photographs sent by the Manx Wildlife Trust to the Cornwall Seal Group (Research Trust) revealed that the same seal, nicknamed Tulip Belle, has been a regular visitor to the South West since 2001, returning to Calf of Man every couple of years to have her pups.

Lara Howe, Manx Wildlife Trust’s Marine Officer, says:

"This is a first for us. We knew that seals travel within the Irish Sea, but we had no idea that they would go as far as Cornwall. When I sent our Manx seal photos to the Cornwall Seal Group, it was a bit of a long shot and we were all surprised that we found a match. It shows that seals will swim great distances for food and a place to pup, highlighting the importance of a network of marine protected areas around the UK, so that wherever marine wildlife goes there are healthy seas to support them.” 

Short snouted seahorse Hippocampus hippocampus, during survey, by Matt Slater

Rare Seahorse found in Fal fishery – proof that sustainable oyster fishing has a bright future

Seahorses are extremely rare in Cornish waters, and very rarely recorded. Cornwall Wildlife Trust’s Marine Officer, Matt Slater, came face to face with one while helping on a survey of the Fal oyster beds being run by Cornwall Inshore Fisheries and Conservation Authority (IFCA). This was the first seahorse ever to be found during the survey.

The annual oyster survey monitors the catch rates of oysters and other shellfish giving an indication of the health of the estuary. Finding a rare seahorse adds to growing evidence that the Fal estuary, with its well managed sustainable fishery, is still productive and in reasonable health.

The seahorse was identified as a female, short-snouted seahorse (Hippocampus hippocampus). It was photographed and then swiftly returned unharmed to the sea in the same position that it was found.

The bad news

Pacific oyster considered a threat as waters warm

As noted in The Wildlife Trust's marine review of 2019, warming seas have allowed a boom in numbers of non-native Pacific oysters, threatening to change ecosystems in important estuaries of the south west.

Pacific oysters were introduced to the UK in the 1920s, and then commercial oyster farms were established in the 1950s and 1960s, it was believed that they wouldn’t breed because our waters were too cold. Recently, though, the oysters have spread beyond the farms and trained citizen scientists from Cornwall Wildlife Trust’s Shoresearch Project, along with other partners, are mapping the oyster explosion. In Cornwall the Tamar, Fowey, Fal and Helford estuaries are now heavily inundated with Pacific oysters. Solid Pacific oyster reefs are forming in some areas which are changing the ecosystem and smothering intertidal gravel and mudflats, making it difficult for birds and young fish such as bass and mullet, to forage on these rich and important feeding grounds. Some areas have recorded up to 200 oysters per square metre.

Matt Slater, Marine Awareness Officer at Cornwall Wildlife Trust says:

“Pacific oyster populations have increased hugely in Cornwall and Devon in the last five years and it’s unrealistic to think we’ll be able to eradicate this species, so we’re going to have to manage them the best we can. This is a cautionary tale, showing the unforeseen consequences of introducing new species, and particularly the effect a changing climate is having on marine ecosystems.”

Increase in Cornish Marine Disturbance

Cornwall Seal Group and Research Trust

Marine disturbance increases

The Wildlife Trusts noted that several Trusts reported that wildlife is increasingly being disturbed by people. Trusts reported jet skis frightening dolphins, kayakers scaring seals, drones causing wildlife to flee and increased numbers of tripper boats operating from harbours.  The trauma can separate animal parents from their young and disrupt feeding or successful breeding.

In Cornwall, the Cornwall Wildlife Trust Disturbance Hotline has recorded the highest numbers of dolphin disturbances in the past two years since monitoring began in 2013, with 16 groups of dolphins, 8 each year, alarmed by leisure activities such as jet skiers. Most recent hotline figures (2018) show a total of 245 serious incidents involving marine wildlife, 234 of which involved seals. The hotline took the first call and coordinated action to tackle a particularly distressing incident in Falmouth in which dolphins were harassed by jet skiers in February 2019.

Marine Strandings

Chris Lowe


It was another incredibly busy year for our Marine Strandings Network, with a shocking 243 cetaceans stranding in 2019, the second largest number of strandings in 15 years of recording. This included not just the usual species of porpoise and common dolphins, but also rarer animals such as a bottlenose dolphin, three Rissos dolphin, two striped dolphin, and two pilot whales. Sadly, we also recorded the highest number of Atlantic grey seal strandings in the 25 year history of the Network, with 249 recorded. Many of those stranded in the final few months of the year, associated with the winter storms which impacted the pupping season.

Grey seal by Paul Naylor

Looking forward to 2020

In looking forward to 2020, Ruth Williams, Marine Conservation Manager for Cornwall Wildlife Trust says,

“I am incredibly proud of the work Cornwall Wildlife Trust’s marine team have achieved this past year, but we are not doing this alone! It is really inspiring to see how people are not only becoming more aware of their environment but are taking active steps to help protect our seas, and this is really visible in Cornwall. We have amazing local networks of volunteers, citizen scientists and communities all doing their bit to tackle both local issues such as marine litter, as well as the huge global issues of climate and nature emergencies.

We still have a long way to go but we are committed to working towards healthy seas, so vital for all of us. So, for 2020, join us in our quest to work with nature and our incredible seas, to find solutions to reduce the bad and build on the good!”