Record numbers of common dolphin sightings off Scotland’s west coast
Earth Watch Team 2; 7th May 2007 - 18th May 2007 6th June 2007 Between Gunna Sound and Barra
Sightings of common dolphins across the Hebrides have reached a new record high according to research conducted by marine conservation charity, Hebridean Whale and Dolphin Trust.
Evidence collected during marine research expeditions on the Trust’s specialized research yacht Silurian in 2017 has revealed a dramatic 24% increase from the previous year’s already record-breaking figures.
The findings were made in a research season running from April to October 2017, part of the charity’s unique long-term citizen science project monitoring whales, dolphins and porpoises – collectively known as cetaceans – and basking sharks in the Hebrides.
“We have never documented so many sightings of common dolphins off Scotland’s west coast before. Our findings highlight the importance of on-going monitoring and research to strengthen our understanding of what is taking place in Hebridean waters. It is hard to say what is causing this increase, but a rise in sea surface temperatures linked to climate change could be playing a role,” said Dr Lauren Hartny-Mills, Science and Policy Officer at Hebridean Whale and Dolphin Trust.
During 2017, the Trust recorded 93 sightings of common dolphins – its highest total ever, up from 75 sightings in 2016. The encounters included a total of 1,340 individual animals – down from 2016’s high of 2,303, due to smaller group sizes and fewer super pods.
Over the past two years, the charity has also recorded a higher than average number of sightings of white-beaked dolphins – with 14 sightings of 74 individuals in 2017. Generally preferring colder, deeper waters in the North Atlantic, white-beaked dolphins have distinct white noses. These fast, acrobatic swimmers are usually spotted further away from the coast – favouring sites around the Outer Hebrides, and usually seen in groups of five to 20 individuals.
Lauren Hartny-Mills said: “Silurian is more frequently travelling further north in her surveys, with trips now departing from Ullapool. This could explain why more white-beaked dolphins are being spotted each year. It also highlights the need for further research in the far north of our survey area, where white-beaks reside.”
The 2017 survey season – which recorded nearly 3,000 whales, dolphins, seals and sharks during more than 1,100 sightings – also saw large numbers of minke whales, with 62 sightings of 80 individuals, and Risso’s dolphins, with eight sightings of 58 individuals. These sightings are similar to numbers recorded in previous years.
