ANNEXURE 1: Microscopic photographs of A: Anabaena flosaquae (x 400), B: Amphidinium sp (x 400), C: Amphipora alata (x 400), D: Camphylodiscus clypeus (x 400), E: Cosmarium sp (x 400), F: Cyclotella sp (x 400), G: Cymbella sp (x 100), H: Licmophora lyngbyii (x 400), I: Mougeotia sp (x 400), J: Navicula sp (x 400), K: Navicula radiosa (x 400), L: Navicula festiva (x400), M: Nitzschia closterium (x 400), N: Nitzschia sp (x 400), O: unidentified diatom (x 100), P: Gyrosigma kutzingii (x 400).