The latest findings were made in a research season lasting from May to October 2016, as part of the trust's unique long-term citizen science project monitoring whales, dolphins and porpoises – collectively known as cetaceans – as well as basking sharks in the Hebrides.
These annual research surveys depend on paying volunteers, with 71 welcomed aboard in 2016 – working with marine scientists on visual surveys and acoustic monitoring with underwater microphones or hydrophones, and identifying individual cetaceans through photography.
The Isle of Mull-based organisation now holds data from more than 95,000km of survey effort. It aims to pass the 100,000km milestone during 2017, and it is currently recruiting volunteers to support this by working as citizen scientists onboard Silurian for periods of almost two weeks from April to September.
Alison Lomax, Director of Hebridean Whale and Dolphin Trust, said: “The impressive range of species documented in our at-sea surveys last year is a powerful reminder that Scotland's west coast ocean environment is home to remarkable marine life. Long-term scientific studies of this globally-important habitat and its inhabitants are crucial if we are to ensure a secure future for the Hebrides' spectacular cetaceans.”
During 2016, Silurian – previously used in filming of the BBC's The Blue Planet series – covered more than 5,000 nautical miles, compared to an average of almost 4,000 miles annually over the previous 14 years. Its crew documented more than 1,300 cetaceans and basking sharks, and recorded almost 700 hours of underwater detections of cetaceans using specialist listening equipment.