Medium- term distribution of the micro-phytoplankton functional groups in a temperate shallow urban lagoon (Gualeguaychú, Argentina)

GIANELLO, DIAMELA; CRETTAZ-MINAGLIA, MELINA CELESTE

Congreso; Society for freshwater science (SFS) virtual annual meeting; 2021

Functional groups (FGs) classification based on individual traits of phytoplankton and the environmental conditions has been increasingly applied as a bioindicator tool. From May-2015 to August-2019, 25 micro-phytoplankton (MP) sampling were carried out in the lagoon of Parque Unzué using a net (pore= 30 µm) in 3 sampling stations (n=75). MP was identified down to the lowest taxonomic level, and classified into FGs. Forty-nine genera were identified distributing in 6 taxonomic groups: Chlorophyceae (15), Bacillariophyceae (9), Euglenophyceae (5), Cyanophyceae (6), Zygnemataceae (2), and Dinophyceae (2). Of the total of the genera, 37 were classified on 20 FGs being the more frequent W1 , J, MP, and P, characteristic of small water bodies, nutrient-rich, and high turbidity. Although its appearance was not frequent, Ceratium (FG = LM), an invasive genus in freshwaters of South America, was recorded in the autumn-2015 and winter-2019 samples. Moreover, no significant differences (p> 0.05) were found between sampling stations, while differences were found between sampling years and climatic seasons. MP and FGs were an important tool that provided easy, low-cost, and fast information on the status of the lagoon on which information was not previously available.