Multidisciplinary Science Expedition to the Chagos Archipelago
The team of four arrived in Male on 6 January 2024, where they joined the Patrol Vessel, Grampian Endurance. Scientific work commenced on 8 January 2024. During the five transit days down to Diego Garcia, Dr Clara Diaz took conductivity, depth and temperature (CTD) profiles to depths of up to ~130 m at various locations to establish the current depth of the region’s thermocline. In the south of the Great Chagos Bank, Isha recovered a hydrophone that has been recording dolphin and whale sounds since it was deployed in June 2023. At the same location, Jessica Savage sampled water for microplastics.
Whilst on Diego Garcia, the scientists collected microplastics samples and tested a remotely operated vehicle (ROV). Volunteers from the UK and US military were recruited to assist with manta ray surveys and to help deploy satellite tags. Dr Joanna Harris and the volunteers conducted a total of 64 hours of surveys around the island. The team of four were then joined by another expedition group, from the seabird project (Heriot Watt University, University of Exeter, ZSL), before they all embarked the Grampian Endurance once again and travelled to Nelson Island. Upon arrival, the seabird team disembarked to camp on the island for 10 days whilst the others conducted plastic transects, collected sand samples and carried out reef manta ray surveys. During their time at sea, the weather was very unpredictable with some challenging conditions which prevented some work from being conducted. However, scientific research was conducted wherever possible including CTD deployments, DropCam surveys of MCEs, ROV exploration, reef manta ray identification and tagging, sand and water sampling for microplastics. Isha also successfully deployed two hydrophones and conducted dolphin and whale surveys during transiting time.
During time spent on Diego Garcia, all teams engaged in a well attended outreach session, giving four scientific talks. Following the talks, the audience participated in a competition to win science-related merchandise and got to experience diving with reef manta rays through the power of virtual reality.
The team were hugely grateful for all the support they received on the Grampian Endurance and on Diego Garcia to facilitate their research.
