Solubility of Atmospheric Nutrients over the Eastern Mediterranean: Comparison between Pure-Water and Sea-Water, Implications Regarding Marine Production

Aerosol filter samples were selected from sample library of Erdemli site; located on the coastline of the Eastern Mediterranean, in order to carry out solubility experiments. The nutrient (PO4 , Sidiss, NO3 and NH4 ) solubilities were investigated by using pure-water and sea-water. The arithmetic means of phosphate and dissolved silica indicated distinct difference (larger than 50 %) between pure-water and sea-water whereas; the calculated mean concentrations of nitrate and ammonium did not reveal substantial discrepancy for pure-water and sea-water extractions. The difference for phosphate and silicate might be attributed to pH and ionic strength of sea water, size distribution and association of phosphate/silicate particles with less soluble compounds such as calcium phosphate, kaolinite, opal, quartz and origin of the aerosol species. The difference between pure-water and sea-water extractions for nitrate and ammonium was estimated to be small, corresponding to 1 % to -3 %. This similarity can be ascribed to highly soluble chemical forms such as NH4NO3, Ca(NO3)2, NaNO3 (NH4)2SO4 and NH4HSO4. Calculations revealed that atmospheric P flux would sustain 0.4 % and 0.9 % of the primary production reported for coastal and offshore waters of Cilician Basin. Whereas, atmospheric nitrogen contribution on primary production would be as high as 3.7 % and 8.4 % in coastal and offshore waters, correspondingly. The impact of atmospheric input on the marine productivity became more important particularly during the stratified periods such as summer and autumn. During these period, atmospheric P input might sustain 80 % of the new production whereas, atmospheric N input might support 8 times higher new product than that detected for surface waters.