Why Scratchy, White Stripe, and Topless are causing a stir in south west waters

By: Clare Fischer
Date posted: 20 December 2017

England’s only resident population of bottlenose dolphins has been discovered by researchers who say it’s ‘incredibly exciting.’

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© Trevor Scouten

If the science shows strong residency in the area, then there is a good reason to have a specific MPA for cetaceans.

Dr Jean-Luc Solandt,
MCS Principle Specialist Marine Protected Areas

The Cornwall Wildlife Trust have assigned the dolphins numbers but three very distinctive ones have been have been named because of the markings on their fins. Scratchy, White Stripe, and Topless – who is missing the tip of its fin.

Researchers identified 98 individual bottlenose dolphins and were able to define a distinct group of 28 that were resident throughout the year in shallow coastal waters mainly in Cornwall particularly St Ives Bay and Mount’s Bay - but also in Devon and Dorset.

Rebecca Dudley, of the University of Plymouth, analysed 3,843 records to identify the population.

Bottlenose dolphins can be recognised by their dorsal fin, which has a distinctive shape and markings - as unique to an individual dolphin as a fingerprint is to a human.

The trailing edge of the fin is most commonly used to identify a dolphin as it is the most distinguishable area because it’s susceptible to tearing and, once torn, the tissue does not regenerate, causing permanent notches.

Dr Jean-Luc Solandt, MCS Principle Specialist Marine Protected Areas, said the discovery of this resident pod should allow us to create bespoke protection for a defined range for the animals.

“Many areas of the sea are hotspots for dolphins and whales because of the presence of large amounts of prey either coming from or residing in deep waters. This makes them stay in the areas of such favourable food sources for considerable amounts of time, making an area-based protection mechanism such as a Marine Protected Areas really effective.

“It would have to have strict rules associated with entanglement, by-catch and noise restrictions so as not to damage the population,” said Dr Solandt. “If the science shows strong residency in the area, then there is a good reason to have a specific MPA for cetaceans.”

Ruth Williams, marine conservation manager at the Cornwall Wildlife Trust, described the discovery as “incredibly exciting”.

“Further work is needed but this is a huge step forward and I am proud of what our partnership between Cornwall Wildlife Trust, scientists and boat operators has achieved,” she said. “The future of these iconic animals is in our hands and we need to make sure the few we currently have in the south west are given the protection not just to survive, but to thrive.”

Conservationists say the discovery could have implications for the conservation of the dolphins, who currently receive no specific protection in their home range.

Dolphins are a wide-ranging species, with strong evidence needed to show that an area is important before protection can be considered.

The UK’s other two resident bottlenose dolphin populations - in the Moray Firth in Scotland and Cardigan Bay in Wales - both have protection.

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An area over 9 times the size of Wales is now in marine protected areas in the UK, but less than 1% is considered by MCS scientists to be well managed

Over 1,000 marine wildlife sightings were reported to MCS last year

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