ASSESSING CYMODOCEA NODOSA SEEDLING DEVELOPMENT UNDER OCEAN ACIDIFICATION SCENARIO

Arianna Pansini

Alessia Crobu

Mariangela Moro Merella

Paraskevi Nomikou

Giulia Ceccherelli

1,3

, University of Sassari, Via piandanna 4, Sassari, - 07100, Italy

, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Ilissia, Athens, - 15771, Greece

, National Biodiversity Future Centre, Piazza Marina, 61, Palermo, - 90133, Italy

Progetto di ricerca finanziato dal premio “Luigi e Francesca Brusarosco” 2024 As a result of the anthropogenic emissions, ocean acidification (OA) has been consistently evidenced to have profound impacts on marine biota. The effects of high pCO2 levels on seagrasses have been a subject of global concern, although the evidence is not uniformly consistent. Furthermore, the responses exhibited by early life stages, specifically seedlings, remain to be fully understood. This study aimed at evaluating how projected Mediterranean Sea OA affect the survival and the morphological development of Cymodocea nodosa seedlings coming from two different thermal origins. Seeds originated from two warm and two cold Mediterranean sites were collected during spring 2025 and transplanted in Vulcano and Milos Islands, both characterised by a submarine hydrothermal shallow system. For each island, two different pH sites were selected for the transplanting field experiment: the control area (pH 8.14 – 8.15) and the low pH area (pH 7.45 – 7.6), representing the nowadays conditions and worst-case OA future scenario, respectively. For each site, 40 seeds from each origin were put for germination and seedling development (summer 2025). Results provide evidence on the adaptative, and acclimation responses of seedlings originated from different coasts and subjected to the future OA if an interactive effect of the OA x thermal origin was highlighted on their survival and morphology. Overall, this study evidenced that seagrass responses to OA may be not unidirectional and could depend upon in-situ characteristics. The need of further in-situ research, in combination with manipulative laboratory experiments that consider wider duration of exposure and range of pH conditions is needed to identify further acclimation responses of C. nodosa to an incoming acidified Mediterranean Sea, addressing eventual restoration management under a climate change scenario.

Ecosistemi e cambiamento climatico

Premio Speciale “Luigi Michaud” Migliore articolo pubblicato su rivista internazionale ISI nel 2024