| dc.description.abstract | The Belumai River is located in Tanjung Morawa District, Deli Serdang Regency, North Sumatra. Households living along the banks of the Belumai River use the river water directly and indirectly for daily needs such as drinking water, bathing, washing, and toilets, agriculture, freshwater fisheries, and water recreation (bathing). The purpose of this study was to determine the diversity of freshwater fish species found in the Sei Belumai River, Tanjung Morawa, and to determine how the diversity of freshwater fish species is influenced by the water quality of the Sei Belumai River. This research was conducted from October to December 2024. The results obtained a total of 109 fish species at each station, 8 species, 5 families, and 4 orders. Abundance (K) values ranged from 4.04 ind/m2 to 14.90 ind/m2. Diversity index values ranged from 0.93 to 1.66, evenness index from 0.63 to 0.85, and dominance index from 0.21 to 0.48. Principal component analysis values showed that clarity, pH, temperature, BOD, total nitrogen, current, and depth were negatively correlated with fish diversity and abundance. Meanwhile, TDS, DO, temperature, and phosphate showed a positive correlation with fish diversity and abundance. The correlation values and interpretation ranged from 0.162 to 976, with categories ranging from very weak to very strong. | en_US |