Primary production in the Saudi coastal waters of the Arabian Gulf.

The Arabian Gulf is a warm (summer SST > 30 °C) and hypersaline (salinity > 40 psu at any time) marginal sea of the Indian Ocean. This paper reports on a 3-year study of seasonal and spatial changes of primary production and associated physico-chemical and biological parameters in the coastal waters of Saudi Arabia in the western Arabian Gulf. The primary production rates were low and yet showed a seasonality, with a major spring peak and a minor autumn peak, and a possible significant role for heterotrophs. While the strong relationships between the net changes of carbon uptake and nutrients between seasons showed a control of primary production by the availability of nutrients, the decrease in primary production between spring and summer when nutrients continued to increase suggests that the primary production at this time could have been controlled by higher ambient temperatures and intensities of incident light. • This Ms presents data, for the first time, on nutrients and primary production in a large sea area of the Arabian Gulf. • The waters are oligotrophic, with low rates of primary production. • Nutrients play a major role in controlling primary production. • Sea surface temperature and incident light may negatively influence primary production between spring and summer. • Increased anthropogenic inputs may render eutrophic specific locations of this pristine sea area. [ABSTRACT FROM AUTHOR]