230-233Urea concentrations at the surface are high both in coastal and offshore waters in the region north of 15° N (0.3-7.76 µg at N/litre) and low in the region south of this latitude (0-1.5 mu g at N/litre). Vertical distribution shows peak at some levels and very low concentrations at others. Urea concentration increases towards the central west coast of India. Comparison with the other inorganic nutrients indicates that urea constitutes >10% of the available nitrogen in the euphotic zone (0-100 m). This shows that urea forms a significant nitrogen source for marine phytoplankton in the west coast of India
