EDP Baixo-Sabor: Phytobenthos – Ecological Monitoring Program [2015-2019]

Epilitic communities were sampled in accordance with the Sampling Protocol and analysis for phytobenthos - diatoms (INAG 2008). In each sampling point a number of stones totaling a colonized surface of ≈100 cm2 was examined, avoiding, whenever possible, the shaded areas, as well as the areas without current or with very high water velocity. All samples were fixed “in loco” with commercial formaldehyde (37%) and brought to laboratory, where they were subjected to the nitric acid method (INAG, 2008). All diatoms present were counted and identified up to the lowest possible taxonomic level using several floras, namely those of Germain (1981) and Krammer and Lange-Bertalot (1986, 1988, 1991a and 1991b), as well as the IBD manual (Prygiel and Coste, 2000).