By R Ramesh
The author is Senior Professor and Project Director, ISRO_GBP, Geoscience Division, Physical Research Laboratory, Ahmedabad. firstname.lastname@example.org
Nitrogen an essential macronutrient of the oceanic ecosystem, can limit the biological production if not available in a suitable form or concentration. This article looks at the role of nitrogen in the waters of the Arabian Sea.
Most plants and bacteria produce energy that the rest of the ecosystem can use, and are the primary producers; and, the rate at which they produce the energy is labelled productivity which plays a crucial role in the global carbon cycle. Roughly half of this productivity occurs in the oceans, by microscopic plants called plankton. Thus, ocean primary productivity (OPP) is defined as the carbon per unit time and unit area set by the ocean phytoplankton’s photosynthesis. New productivity is part of the oceanic primary productivity supported by nitrates, brought into the euphotic (sunlit) zone from deeper waters through a physical processes; while regenerated productivity is productivity supported by ammonium and urea, derived from biological processes occurring within the euphotic zone. Regenerated production is fuelled by nitrogen recycled biologically in the euphotic zone, ammonium (NH) being the principal form. New production, on the other hand, is fuelled by external sources,...