Study on the impact of environmental pollution: Parasitic infestation and conditions factor of fish living in amalgamation ponds

Abstract

Abstract Artisanal and small-scale gold mining activities often leave pools. During rainy seasons, they form lakes where various species of fish live. Fish that live in amalgamation lakes or near streams may obtain contaminated water from mercury. Therefore, the aims of this research was to investigate the species of parasites as well as the condition of tilapia that live in the former pool of gold mining in Bombana Regency, Southeast Sulawesi, Indonesia. The samples that were used were tilapia fish (Oreochromis niloticus) with a total sample size of 40 fish. Fish condition factor was evaluated on the basis of body weight and length data. Examination of ectoparasites and endoparasites were performed on fish for prevalence and intensity parameters, while the measurements of heavy metals Hg were carried out on water and sediment and sampled four times. Based on the research results, three species of parasites attacking on external body of fish (ectoparasites) were found, namely Dactylogyrus sp., Ergasilus sp., and Microsporidia (Glugea sp.). Prevalence of those three parasites ranged from 10-90%, while intensity ranged from 1.7-3.5 parasite/fish. Condition factor of tilapia was between 2.70-3.81. Moreover, an average of Hg concentration was higher in sediment (0.167 ppm) than in water (0.039 ppm). Although it seems that the presence of parasites in fish is still relatively low and fish shows normal growth, people should not consume fish live in ex-mining ponds often for the health of the local community.