From nitrogen enrichment to oxygen depletion: a mechanistic model of coastal marine ecosystems response

• Main Authors: Cosme, Nuno Miguel Dias, Koski, Marja, Hauschild, Michael Zwicky
• Format: Conference Object
• Language: English
• Published: 2015
• Subjects: /dk/atira/pure/sustainabledevelopmentgoals/life_below_water; SDG 14 - Life Below Water; Arctic; Arctic Ocean; Zooplankton
• Online Access: https://orbit.dtu.dk/en/publications/6036d0be-ddd1-470a-a006-5377be16d776; https://backend.orbit.dtu.dk/ws/files/118303507/From_nitrogen_enrichment.pdf

Nitrogen (N) emissions from anthropogenic sources may enrich coastal waters and lead to marine eutrophication impacts. Processes describing N-limited primary production (PP), zooplankton grazing, and bacterial respiration of sinking organic carbon, were modelled to quantify the potential dissolved oxygen (DO) consumption as a function of N input. Such indicator is the basis for an eXposure Factor (XF) applied in Life Cycle Impact Assessment (LCIA) to estimate impacts from N enrichment. The Large Marine Ecosystems (LME) biogeographical classification system was adopted to address the spatial variation of the modelled parameters and to characterise spatially differentiated N-emissions. Preliminary XF results range from 0.5 kgO2·kgN-1 in the Central Arctic Ocean to 16 kgO2·kgN-1 in the Baltic Sea, out of a total of 66 LME-dependent XFs. All the relevant processes were included in a mechanistic model and the uncertainty of the driving parameters is considered low. The presented XF estimation method contributes with a central component for site-dependent characterization factors (CFs) for marine eutrophication, to be coupled with environmental fate of N emissions and effects of oxygen depletion on biota.