Determining the Fluxes and Relative Importance of Different External Sources and Sinks of Nitrogen to the Israeli Coastal Shelf, a Potentially Vulnerable Ecosystem
| Autor: | Tal Ben Ezra, Anat Tsemel, Yair Suari, Ilana Berman-Frank, Danny Tchernov, Michael David Krom |
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| Jazyk: | angličtina |
| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | Water, Vol 16, Iss 18, p 2585 (2024) |
| Druh dokumentu: | article |
| ISSN: | 2073-4441 70549044 |
| DOI: | 10.3390/w16182585 |
| Popis: | While the biogeochemical properties of the Israeli coastal shelf (ICS) are similar to adjacent pelagic waters, the external sources of inorganic nitrogen (N) are very different. The main source of ‘new’ N to the pelagic zone is deep winter mixing, with minor contributions from atmospheric deposition and eddy diffusion across the nutricline. For the ICS, major N sources include offshore water advection (260 × 10⁶ mol N y−¹), atmospheric input (115 × 10⁶ mol N y−¹), and riverine input (138 × 10⁶ mol N y−¹), which primarily consists of treated wastewater and stormwater runoff. Direct pollutant discharge from sewage outfalls and submarine groundwater discharge are relatively minor. Key N sinks are new production (420 × 10⁶ mol N y−¹) and sediment deposition and uptake (145 × 10⁶ mol N y−¹). Inputs of nitrate and ammonium were similar and dominant in winter. Unlike temperate shelves, where riverine input is dominant, here it was only slightly higher than atmospheric input, with net N advection onto the shelf being significant. External N inputs did not change net primary production (NPP) by more than ~30% or affect dominant pico and nanophytoplankton genera, except in localized patches. This study offers baseline values for future climate and environmental change assessments. |
| Databáze: | Directory of Open Access Journals |
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