Guanicid and Phmg Toxicity Tests on Aquatic Organisms

POŠTULKOVÁ EVA, KOPP RADOVAN. 2016. Guanicid and PHMG Toxicity Tests on Aquatic Organisms. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 64(1): 129–134. The emergence and development of new algicidal products is caused by the ever increasing popularity of garden ponds as well as the use of these products in the fi sheries sector, especially for disposal of cyanobacteria and algae. Most frequent means of combating cyanobacteria and algae are applications of algicidal substances. Newly developed algaecides include Guanicid and polyhexamethylene guanidine hydrochloride (PHMG). The aim of the study was to identify toxic eff ects of Guanicid and PHMG on zebrafi sh (Danio rerio) and green algae (Desmodesmus communis). We determined the acute toxicity in fi sh according to ČSN EN ISO 7346-1, and conducted the freshwater algae growth inhibition test according to ČSN ISO 8692 methodology. For inhibition tests with green algae we chose Guanicid and PHMG concentrations of 0.001, 0.005, and 0.010 ml/L. For fi sh shortterm acute toxicity tests we chose Guanicid concentrations of 0.010, 0.050, 0.150, 0.200, 0.250, and 0.300 ml/L and PHMG concentrations of 0.010, 0.025, 0.050, 0.075, 0.100, and 0.125 ml/L. In case of zebrafi sh (Danio rerio), the LC50 value for Guanicid is 0.086 ml/L, while the LC50 value for PHMG is 0.043 ml/L. Eff ects of Guanicid on inhibition of green algae (Desmodesmus communis) appear highly signifi cant (p < 0.010) at a concentration of 0.010 ml/L. For PHMG, these eff ects are highly signifi cant (p < 0.001) at concentrations of 0.005 and 0.010 ml/L in 48 hours.