The Mediterranean seagrass Posidonia oceanica is a vital ecosystem engineer that provides key services, including acting as a natural filter for trace metals and serving as a bioindicator of coastal pollution. However, the impact of nutrient enrichment, a widespread anthropogenic stressor, on metal accumulation in seagrasses remains unclear. This study investigated how nutrients (N, P) fertilization influences the accumulation of trace metals (Fe, Cd, Cu, Zn, Ni, Mn, Pb) in P. oceanica leaves and rhizomes over a 13-month in situ experiment in an oligotrophic meadow in Spain. Short-term effects (4-33 days) were negligible, while long-term (seasonal) responses were metal-, tissue-, and season-specific. Fertilization consistently increased Fe in rhizomes and in leaves during winter, enhanced Cd and Zn in rhizomes, but reduced Cd and Mn in leaves. Cu and Ni showed no response. The observed shifts likely reflect both nutrient-metal interactions and metal-metal competition, such as Fe-Mn antagonism, which may involve shared uptake pathways. These findings suggest that nutrient enrichment can promote the accumulation of specific metals, with potential ecological consequences. Overall, nutrient availability modulates the metal accumulation capacity of P. oceanica, affecting its role as a bioindicator and highlighting the need to integrate nutrient-metal dynamics into conservation and management.
promotor/supervisor feedback
nothing yet
