Abstract
São Luis or Ancão Inlet is the most western of the six inlets of the Ria Formosa lagoon, in southern Portugal. This inlet contributes relatively little to the water volume exchange over a tidal cycle (~10%). Temperature, salinity, pH, dissolved oxygen, and chlorophyll a and nutrient concentrations were measured hourly at the surface, at an intermediate level, and near the bottom over a complete spring tidal cycle, at a sampling point in the middle of the inlet. Current velocity was also measured hourly over the entire cross-section of the inlet using an acoustic Doppler current meter. From these parameters, the flow rate and the transport of nutrients and chlorophyll a were calculated and integrated over the complete tidal cycle providing the net transport. The results show that this is a well-mixed dynamic inlet where, during spring tide, the tidal signal is evident particularly for the nutrient and chlorophyll a concentrations. The nutrient concentrations were low (almost depleted), while the chlorophyll a concentrations were high (4–6 mg m–3). The estimated transports through Ancão Inlet revealed that there was a net import of chlorophyll a, nitrate, and phosphate to the Ria Formosa lagoon, while silicate was exported to the adjacent coastal area.
Highlights
Ria Formosa (36o58′–37o3′ N, 8o2′–7o32′ W; fig. 1) is a shallow lagoon system located in the south of Portugal
The results obtained confirmed that the chemical characteristics at the Ria Formosa inlets are affected by the tidal range and by physical forcing including winds and, biological processes occurring in the boundary water masses
Chlorophyll a, nitrate, and phosphate were imported into the Ria Formosa
Summary
Ria Formosa (36o58′–37o3′ N, 8o2′–7o32′ W; fig. 1) is a shallow lagoon system located in the south of Portugal. 1) is a shallow lagoon system located in the south of Portugal. It has an area of approximately 80 km, a mean water depth of 3.5 m, a length of 55 km in E–W direction, and a maximum width of 6 km in N–S direction. The Ria Formosa lagoon is a complex inlet-barrier island system, with six inlets that can be divided into three hydrodynamically different subembayments as described by several authors (Salles 2001, Vila-Concejo et al 2002, Bertin et al 2009): (1) the western INTRODUCCIÓN. Tiene un área de aproximadamente 80 km, una profundidad media de 3.5 m, una longitud de 55 km en dirección E–O y un ancho máximo de 6 km en dirección N–S
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
