Hydraulic stopper effect as a regulator of inorganic nutrients distribution in Mar Chiquita coastal lagoon (Argentina)

Abstract

Estuaries are transitional systems that link both land and oceans, with particular dynamics regulated by their own characteristics. The main aim of the present study was the assessment of the effects generated by a strong dry period on the distribution of inorganic nutrients and biological production within Mar Chiquita coastal lagoon, comparing this information with that from periods of precipitation regularly conducted. For this study we selected Mar Chiquita coastal lagoon and analyzed a 20-year data series for concentration and distribution of physical and chemical parameters, in particular salinity, inorganic nutrients (i.e. dissolved inorganic nitrogen, phosphate, silicate) and photosynthetical pigments (i.e. chlorophyll a). We also evaluated the association between these parameters and climate conditions within the region, and found a strong relationship and very quick response to changes. As a result, we report, for the first time in the region, rainfall as a main driver of biogeochemical processes within the estuarine system. The obtained results allowed us to confirm the clear transference processes between land and oceanic systems, and the role of climate as a driver of the corresponding transference processes.