ZOOPLANKTON DIVERSITY AS A RELIABLE INDICATOR OF WATER QUALITY IN DERHAKA RIVER

Abstract

A study on the zooplankton community was conducted in Derhaka River, Seberang Jaya, Pulau Pinang, from November 2023 to January 2024. Zooplankton samples were collected from three stations, with three replicates taken at each station. These samples were then analyzed under a microscope at various magnifications. Fifty-four zooplankton taxa were identified in the Derhaka River, comprising three main groups: Rotifera, Cladocera, and Copepoda. Rotifera was the dominant group, with 46 taxa recorded. In terms of zooplankton abundance, Station 2 had the highest numbers, with 38,611 ± 4.28 ind/m³ in November, 150,000 ± 36.48 ind/m³ in December, and 104,444 ± 23.89 ind/m³ in January. Various physicochemical parameters were measured in-situ, including temperature, conductivity, total dissolved solids (TDS), dissolved oxygen (DO), pH, and transparency. Pearson correlation results indicated that zooplankton abundance had a strong positive correlation with species number (r = 0.804) and a strong negative correlation with DO (r = -0.493). Additionally, there was a significant difference in zooplankton abundance with the sampling stations (p<0.05). The study concludes that human activities or other environmental factors may influence the zooplankton community in the study area. Monitoring human activities that impact the river, along with agricultural practices, is crucial to protect the health and biodiversity of this ecosystem.