DiverSea News The Nexus Mon-ARC Tour
FROM HYDROTHERMAL VENTS TO CITIZEN SCIENCE: DIVERSEA AND NEXUS MON-ARC TOUR ACROSS THE HELLENIC VOLCANIC ARC
The Nexus Mon-ARC flagship tour, carried out between 1 and 15 November 2025 in collaboration with DiverSea, brought together research teams and local communities to explore key marine environments along the Hellenic Volcanic Arc (HVA). The tour focused on advancing marine monitoring while engaging citizens through outreach and hands-on activities, supporting the collection of Essential Ocean Variables (EOVs) and Essential Biodiversity Variables (EBVs), that are crucial for understanding ecosystem change.
Eleven scientists participated in the initiative, supported by over 250 students collaborated, and 20–30 engaged passengers who joined the activities.
Sampling and citizen science activities were conducted at Kos, Nisyros, Santorini, and Milos, targeting shallow and deep sites influenced by hydrothermal activity. A standardized approach ensured data comparability with previous campaigns. Twelve sampling points were visited across the islands, with depths ranging from 1 m to 500 m. Measurements included temperature, salinity, pH, dissolved oxygen, water clarity, nutrients, and heavy metals, along with water and sediment samples for microbial biodiversity, phytoplankton anaylsis, eDNA (or environmental DNA), and microplastic analyses. Equipment used included CTD (conductivity, temperature, and depth) systems, Niskin bottles, Secchi disks, multiparameter meters, FlowCam and PlanktonScope. The total sampling effort exceeded 36 hours, complemented by extensive onboard filtering and thorough cleaning of all sampling equipment to ensure samples were properly prepared for analysis.
A strong emphasis was placed on citizen engagement and education, with public demonstrations of scientific equipment and discussions on environmental threats, pollution, and the need for continuous marine monitoring. These interactions highlighted the value of involving local communities in long-term observation efforts, particularly in geologically dynamic regions.
DiverSea participated actively throughout the expedition alongside partners from NKUA (represented by Yolanda Stranga), NTNU (Murat Ardelan and Mathew Kuttivadakkethil Avarachen), and UGOT (Martin Hasselӧv), and the tour was further supported through collaboration with the Sailing4science, Santory, RAMONES and REMEDIES projects, reinforcing cross-project synergies for marine research and societal impact.