Atmospheric Wet Deposition of Soluble Macro-Nutrients in the Cilician Basin

Abstract

Pulses of mineral dust from North Africa into the Mediterranean region could deposit macro-nutrients (e.g. PO₄ ³⁻ and NO₃ ⁻) (Bergametti et al., 1992) at the sea surface, and possibly contribute to marine biological production. Phosphate, PO₄ ³⁻ is generally known to be the limiting nutrient for phytoplankton production in the Eastern Mediterranean, typically having a high N:P ratio (>20:1) near the sea surface (Krom et al., 1991). Most studies in the western (Rimmelin et al., 1999) and the eastern (Herut et al., 1999) Mediterranean regions have been directed at the determination of macro-nutrient contents of wet deposition. Particular attention has been given to inorganic nitrogen for its major role in anthropogenic air pollution related to industrial/agricultural activities or traffic emissions, which are partly responsible for increased acidity of rainwater. In order to estimate wet deposition atmospheric fluxes of macro-nutrients, soluble inorganic phosphate (PO₄ ³⁻), nitrate (NO₃ ⁻) and nitrite (NO₂ ⁻) concentrations in precipitation (from February 1996 to June 1997) have been measured at a coastal sampling site, Erdemli, Turkey. Soluble inorganic P, a reactive, bioavailable, limiting macro-nutrient in the oligotrophic waters of the eastern Mediterranean was studied with respect to its contribution to biological productivity.