title: The role of highly sratified nutrient-rich small estuaries as a source of dissolved inorganic nitrogen to coastal seawater, the Qishon (SE Mediterranean) case.
abstract: We studied the role of small, highly stratified, sulfate and nutrient enriched estuaries, as a source or sink of inorganic nitrogen species, using the Qishon estuary at the Mediterranean coast of Israel, as a case study. Measurements of nutrient concentrations, δ(15)N and δ(18)O of nitrate+nitrite, δ(13)CDIC and δ(18)OH2O were performed during 2008-2009 along the upper-fresh and lower-saline water masses, as well as sediment porewater depth-profiles. Such estuaries are characterized by relatively low removal flux of NO3(-) (via sedimentary denitrification) and enhanced (×3) upward flux of NH4(+) (via sulfate reduction), attributed to the penetration of seawater of low NO3(-) and high dissolved oxygen and sulfate concentrations. The role of such small estuaries in releasing dissolved inorganic nitrogen, especially in sensitive oligotrophic areas as the Levantine basin and in the long-term, as a result of enhanced seawater penetration due to the expected sea level rise, has important environmental policy implications.
authors.affiliation: Department of Geological and Environmental Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Efrat
authors.initials: E
authors.lastname: Eliani-Russak
authors.forename: Barak
authors.initials: B
authors.lastname: Herut
authors.forename: Orit
authors.initials: O
authors.lastname: Sivan
mesh_terms: D004784:Environmental Monitoring; D063366:Estuaries; D007557:Israel; D009584:Nitrogen / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014876:Water Pollution / Q000706:statistics & numerical data
chemical_list: D014874:Water Pollutants, Chemical; D009584:Nitrogen