Yasser El-Nahhal and Shireen El-Hams
Application of pesticides creates many environmental problems and exposes the non-target organisms to health risks. This study aimed to determine the effects of Bromacil, Thiabendazole, and Malathion to cyanobacterial mats growth. Effects were measured as population growth reduction and metabolic activity changes. Cyanobacteria mats showed four growth phases under laboratory condition indicating adaptation and normal growth. Significant growth reduction in treatments containing Bromacil and Thiabendazole were observed, whereas treatments containing Malathion showed increased population growth to cyanobacteria. Ammonium production was severely reduced in treatments containing Bromacil and Thiabendazole, whereas treatment containing Malathion had no effect on ammonium production. Mixtures containing Malathion showed antagonistic effect, whereas mixtures containing Bromacil and Thiabendazole showed increased effect on Electric Conductivity (EC) reduction and pH changes. We concluded that Bromacil and Thiabendazole strongly affect cyanobacterial mats growth; therefore, the ecosystem should be free from them to avoid damage to the cyanobacterial mats.
