Dissolved nutrients, preformed nutrients and calculated elemental ratios in the south-east mediterranean-sea
The Mediterranean Sea has been described as the most impoverished large body of water in the world. Number of studies have determined nutrient concentration in the western and central Mediterranean; in this preliminary study, we present data from 25 stations in the Levantine basin of the eastern Mediterranean. The surface layer, to a depth of 150 m, had a silicic acid content of 1-2-mu-M and a nitrate concentration of less than 1-mu-M, while the maximum reached at depth was 5.4-6.5-mu-M nitrate and 9.9-14.6-mu-M nitrate and 9.9-14.6-mu-M silicic acid except for three stations close to the Egyptian coast where a value of 17-mu-M was reached. There was sometimes a small nitrate maximum (0.1-0.5-mu-M) at 600 m (400-800 m). Based on temperature, salinity and dissolved nutrient data, a warm-core eddy was found south of Cyprus in a position similar to that observed previously. Preformed nutrients calculated in the usual manner gave negative values and could not be used as a tracer for water mass type. The elemental ratio (O:N) for decomposing organic matter was calculated to be 138:11.0-13.0 which is considerably different from the usual Redfield ratio.