The annual depositional flux of carbon (C), nitrogen (N), and phosphorous (P) to the sediments under a northeast Spain Posidonia oceanica meadow was evaluated, and the sources and fate of the material deposited elucidated. The annual deposition of carbon represented 198 g C m-2 yr-1, 72% of which was derived from the seston and 28% from P. oceanica detritus. The depositional flux was poor in nitrogen (13.4 g N m-2 yr-1) and phosphorous (2.01 g P m-2 yr-1), although comparable to the nutrient inputs required to support the growth of P. oceanica. Remineralization in the sediment only returned 15.6 g C m-2 yr-1, yielding a net carbon accumulation of 182 g C m-2 yr-1. Our results show that in the Mediterranean littoral P. oceanica meadows are important sites of net organic carbon burial, derived from sedimented sestonic particles and seagrass detritus.
ASJC Scopus subject areas
- Aquatic Science