HSPN participates in the five-year national project Greek Seagrass Alliance (GISA), an integrated initiative aimed at enhancing knowledge, awareness and community engagement regarding the importance of seagrass ecosystems in Greece. Building on the successful experience of the Posidonia Alert initiative in the Cyclades, the project now expands to a national scale, adopting a coordinated approach that includes awareness campaigns, educational programs, community engagement activities and targeted advocacy towards public authorities, professionals and users of the marine environment. The actions of GISA are implemented across twenty selected coastal areas of the country, identified based on their ecological significance and the dynamics of their local communities, with the guidance and expertise of all participating partners.

The overall coordination of the project is carried out by the Cyclades Preservation Fund (CPF), which oversees management, strategic planning, and partner collaboration. The founder and primary funder of the initiative is the Seacology Foundation. The project brings together organizations with strong scientific and social expertise, including the Hellenic Centre for Marine Research (HCMR), which provides scientific guidance, monitoring methodologies and ecological data on seagrass ecosystems, as well as the Hellenic Society for the Protection of Nature (HSPN), which contributes its extensive experience in environmental education, awareness-raising and advocacy. The Ionian Environmental Foundation (IEF) and the Argosaronic Environmental Foundation (AEF) play an essential role in supporting local implementation in their respective regions, while Aenaos Thalassa strengthens stakeholder engagement and community participation.

The project is structured around five main thematic areas, covering overall management and monitoring, the development of a unified communication and awareness strategy, the creation of educational material and school-based activities, the empowerment of local communities through participatory actions and the promotion of collaboration with policymakers and professionals linked to the marine environment. Through a multidisciplinary and multi-level approach, GISA aims to contribute meaningfully to the understanding of the ecological value of seagrass meadows, while fostering public participation and encouraging practices that support the sustainability of coastal ecosystems.