The number of common dolphins, found in the waters off western Scotland, has substantially increased, prompting the Hebridean Whale and Dolphin Trust to ask volunteers to help marine scientists in investigating the occurrence.
In a recent presentation at the European Cetacean Society, experts from the trust revealed that the encounter rate with common dolphins, which are also called leumadair or "jumper" in Gaelic, has more than doubled in the past 12 years.
This may seem like good news, experts say, since common dolphins rarely appear in the Hebrides due to the colder temperature of the waters. They generally prefer to live in southern parts of the coast, where waters reach 10 degrees Celsius or 50 degrees Fahrenheit.
The rise in water temperature in the Hebrides by about 0.5 degrees Celsius per decade could be the reason the common dolphins are beginning to stay in these waters.
"An increase in common dolphins means that those wishing to encounter dolphins in the wild are in luck, but further research is needed to explain why this is happening, the extent to which this has been caused by human activity, and the implications for other cetacean species," said Conor Ryan, Sightings and Strandings Officer of the trust.
According to Ryan, common dolphins go to the Hebrides because of the waters' seasonal food stocks in the spring. People also get a glimpse of the creatures around this season, especially when the dolphins ride the waves of passing boats.
Dolphins also sometimes travel in groups called super-pods consisting of thousands of individual dolphins.
The Hebridean Whale and Dolphin Trust is currently recruiting volunteer dolphin-spotters to work closely with marine experts to help the organization complete its annual survey this summer.
Kerry Froud, the trust's Biodiversity Officer, explained that volunteers onboard the Silurian, a special yacht used during research trips, have helped the trust create a vital database for these studies, allowing researchers to investigate changes in cetacean populations. The information collected also allows the trust to protect the species and habitats observed, including spots designated as Scottish Marine Protected Areas.
Interested volunteers will work with marine scientists for 12 days aboard the Silurian. They will help conduct visual surveys as well as use specialist equipment for acoustic monitoring. Volunteers will also help identify cetacean species through dorsal fin photography.
The researchers will depart either from Tobermory on the Isle of Mull or Kyle of Lochalsh. They will cover areas such as the Mull of Kintyre, Cape Wrath, and St. Kilda during the survey.
Photo: Jay Ebberly | Flickr
