The role of highly sratified nutrient-rich small estuaries as a source of dissolved inorganic nitrogen to coastal seawater, the Qishon (SE Mediterranean) case

Mar Pollut Bull. 2013 Jun 15;71(1-2):250-8. doi: 10.1016/j.marpolbul.2013.02.001. Epub 2013 Feb 26.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Environmental Monitoring*
  • Estuaries
  • Israel
  • Nitrogen / analysis*
  • Seawater / chemistry*
  • Water Pollutants, Chemical / analysis*
  • Water Pollution / statistics & numerical data

Substances

  • Water Pollutants, Chemical
  • Nitrogen