Toksisitas Parakuat Diklorida pada Komunitas Alga Perifiton = The toxicity of Paraquat Dichloride on the Communities of Periphytic Algae

Paraquat dichloride is a chemical compound used to control broadleaf weeds in several crops. The presence of paraquat dichloride in the aquatic ecosystems has effects on the aquatic ecosystems, including non-target organisms such as periphytic algae. Periphytic algae have a significant role in aquatic ecosystems and make extensive contributions to the diversity in aquatic ecosystems due to large amounts of their species, and as one of the sensitive biological indicators of water quality. The research aimed to determine the effect of paraquat dichloride on the periphytic algae communities, in terms of the amount of chlorophyll-a, species richness, density, diversity index and dominance index of periphytic algae. A liter of water from Rawa Pening lake enriched with leaf fertilizer was used for growing periphytic algae in an aquarium. Paraquat dichloride at 0, 0.01, 0.02, 0.04, 0.08 and 0.16 mg/l was added into the aquariums and illuminated with 1,522 lux. An object glass was placed on the bottom of the aquarium and used as an artificial substrate. Object glass was taken on the 7th and 14th after the treatment. Measured parameters were the amount of chlorophyll-a, species richness, diversity index, dominance index and density of periphytic algae. The data obtained were analyzed using two-way analysis of variance with α 5% to determine the effect of the herbicide paraquat dichloride on the parameters measured. The results of this study indicated the presence of the interaction effect of paraquat dichloride and duration of exposure to the amount of chlorophyll-a, density, diversity and dominance index of periphytic algae (p