High new production in the Bay of Bengal: possible causes and implications

Abstract

We report the first measurements of new production (¹⁵N tracer technique), the component of primary production that sustains on extraneous nutrient inputs to the euphotic zone, in the Bay of Bengal. Experiments done in two different seasons consistently show high new production (averaging around 4 mmol N m⁻² d⁻¹ during post monsoon and 5.4 mmol N m⁻² d⁻¹ during pre monsoon), validating the earlier conjecture of high new production, based on pCO₂ measurements, in the Bay. Averaged over annual time scales, higher new production could cause higher rate of removal of organic carbon. This could also be one of the reasons for comparable organic carbon fluxes observed in the sediment traps of the Bay of Bengal and the eastern Arabian Sea. Thus, oceanic regions like Bay of Bengal may play a more significant role in removing the excess CO₂ from the atmosphere than hitherto believed.