Nutrient distribution in a mangrove estuary in Bahia de Chame

The spatiotemporal distribution of environmental variables and nutrients was evaluated along the Salado River estuary in the mangroves of Chame Bay. Four samplings were carried out, two in the rainy season and two in the dry season at three sites within the estuary and one external site with marine influence. Hydrological parameters were measured in situ and water samples were collected to determine nitrate $\left(\mathrm{NO}_{3}{ }^{-}\right)$, nitrite $\left(\mathrm{NO}_{2}-\right)$, ammonia $\left(\mathrm{NH}_{4}^{-}\right)$and phosphate $\left(\mathrm{PO}_{4}{ }^{3-}\right)$ in surface water. Gradients were detected in the spatial distribution of hydrological parameters and nutrients from the parts with greater fluvial influence to the external area of the estuary. Specifically, the variability between the salinity data set and the levels of pH and dissolved oxygen, ammonia and phosphate were not different between the internal sectors of the estuary and the site with marine influence, both in the rainy and dry seasons. The results presented are new evidence showing that the Salado River estuary is a system of great complexity, variability and dynamism.