Temporal dynamics of photo-physiological and morphological parameters in Posidonia oceanica seagrass transplants in the Bay of Calvi, Corsica.
Supervisor: Sylvie Gobert
The “UN Decade on Ecosystem Restoration” was declared by the United Nations General Assembly in 2019 and will run from 2021-2030 (Waltham et al., 2020), with the aim of preventing, halting, and reversing the degradation of ecosystems on all continents and in all oceans (Tepper, 2022). A key ecosystem targeted by these efforts is Posidonia oceanica meadows in the Mediterranean, an important aspect of these restoration projects is the monitoring of transplant performance. For this reason, the aim of this study was to investigate the temporal dynamics of photo-physiological and morphological parameters, by measuring the photosynthetic activity, chlorophyll concentration, and iron levels, as well as transplant biometry. Photosynthetic activity was measured using chlorophyll α fluorescence as a novel tool for early assessment of the health status of the transplants- The second objective focused on evaluating whether some artificial substrates (BESE sheets, Coconut mat and Staples) showed better survival rates by testing for differences between the physiological and morphological variables in terms of the origin of the shoots (storm or intermatte fragments) or depth. The overall results showed better survival in the BESE and coconut mat substrates, and the intermattes fragments, regarding the photophysiology of the transplants, no differences were found between substrates or origins, but some differences were found with the controls were found, indicating a possible effect of season or transplant shock in the seagrass. Finally, chlorophyll a fluorescence proved to be an important tool for early detection of the health status of the transplants and the need for further monitoring of this transplantation process to obtain more conclusive results.