So close, so far: differences in long-term chlorophyll a variability in three nearby estuarine-coastal stations

ABSTRACTThree sampling stations located in the inner Patos Lagoon estuary, the lagoon’s mouth and the adjacent coastal beach were visited monthly from the end of 1992 until 2014. The stations are in close proximity, but are distributed along saline and hydrological gradients and had never previously been analysed together. Our main questions were: (1) Are the monthly, seasonal and interannual variations in chlorophyll a (Chl a) similar for the three stations? (2) Is there any type of connectivity among the sites? (3) What forces are responsible for controlling phytoplankton variability at these stations? The three stations showed distinct Chl a variability patterns, with higher concentration and variability at the beach station, where the seasonal variation presented higher values between May and October, seemingly out of phase with the estuarine station, where higher values occurred between September and January. The lagoon's mouth station acted as a transit region and incorporated the variability of the...