Keanekaragaman Plankton di Sungai Wampu Tanjung Pura Kabupaten Langkat, Sumatera Utara

Abstract

Wampu River has abundant natural resources located at Langkat Regency, North Sumatra Province. There are activities surrounding the river that cause changes in the physical-chemical factors of the waters which affects to the diversity of plankton. This study aims to determine the diversity of plankton and to analyze the relationship between physical-chemical factors and plankton diversity in the Wampu River. This study used a purposive sampling method. The results show that there are 25 phytoplankton genera come from 21 families and 7 classes, together with 6 zooplankton genera from 5 families and 3 classes. The abundance of phytoplankton range from 76.8 to 2572.8 ind/L with the highest value of 2572.8 ind/L at station 2, while the abundance of zooplankton ranged from 4.8 to 26.4 ind/L with the highest value of 26.4 ind/L at station 1. The relative abundance of phytoplankton range from 0.66 to 22.01 with the highest value of 22.01 at station 2, while the relative abundance of zooplankton range from 6.67 to 28.95 with the highest value of 28.95 at station 1. The highest frequency of phytoplankton and zooplankton presence is at station 3. The highest phytoplankton diversity index is at station 3 with a value of 2.88 classified as moderate, while the highest zooplankton diversity index is also at station 3 with a value of 1.53 classified as low. The highest phytoplankton uniformity index is found at station 3 with a value of 0.91, classified as high, while the highest zooplankton uniformity index is found at station 1 with a value of 0.99, classified as high. The physical-chemical factors of the water generally meet the quality standards, except for DO, BOD5 and COD which exceed the quality standards. The correlation value of physical-chemical factors with plankton diversity obtain significant results, especially for temperature, pH, turbidity, light penetration, BOD5, COD, nitrate levels and phosphate levels.