British Isles – Scientists have discovered that Risso’s dolphins around the British Isles form a genetically unique population after analyzing DNA from stranded dolphins found in England, Scotland and Wales between 1992 and 2016.

The study found that Risso’s dolphins in British waters are their own genetic group, showing limited mixing with other populations farther away. They are genetically distinct from the closest populations in the Azores, the Mediterranean, and possibly the wider North Atlantic.

“The results support the notion of Risso’s dolphins in British waters having been isolated from other populations for some time. However, we did not sample every nearby part of the Atlantic, so it’s not yet clear where the boundaries of this unit lie,” said co-lead author Nicola Hodgins.

Researchers found no major genetic differences between dolphins from different areas around the British Isles, but there may still be signs that some groups return to or remain in specific locations.

Recent analysis of Scottish Risso’s dolphins found less than 3% matches between individual dolphins identified on the west and northern coasts, suggesting the animals may have strong preferences for certain areas.

Scientists say more genetic samples from nearby regions, including Norway, the Celtic Sea, the south-west English Channel and the Bay of Biscay, are needed to better understand how unique this population is.

Future research combining genetics, behavior, appearance, movements and vocalizations will help researchers understand how Risso’s dolphins use habitats and how best to protect them.

“Good conservation requires habitat-specific management. While Risso’s dolphins are currently managed as a single UK population, local populations can face different threats and use habitats in different ways,” said Hodgins.

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