Organic Matter Derived from a Seagrass Meadow: Origin, Properties, and Quality of Particles |
| |
| Authors: | Branko Velimirov |
| |
| Institution: | University of Vienna, Institute of Zoology, Dept. of Marine Biology;Althanstr. 14, A-1090 Vienna, Austria. |
| |
| Abstract: | Abstract. An investigation of the properties of particles found in wrack beds and suspended in the water body of a Posidonia oceanica system led to the following conclusion: except for the period of the leaf fall and at times of strong water movement (e. g. winter storms), the majority of the particles in the water show no similarity with seagrass particles. This is based on the comparison of C: N ratios and SEM inspection. Information on the magnitude of DOC fluxes in this system led to the formulation of the phase shift hypothesis from DOM to POM. Because wrack particles were shown to have relatively fast settling rates, it is expected that processes like adsorption onto inorganic particles, micellation and aggregate formation have more importance in regulating particle density in the water body than the resuspension of directly fractionated Posidonia debris. The implication of these findings are discussed and the importance of the Mediterranean seagrass P. oceanica as an energy source supporting secondary production in adjacent ecosystems is questioned. |
| |
| Keywords: | Seagrass degradation organic matter quality of particles DOC POC phase shift export |
|
|
