Africa Center of Excellence for Water Management, Addis Ababa University, Addis Ababa, Ethiopia.
Department of Biology, Wollo University, Dessie, Ethiopia.
Environ Monit Assess. 2023 Jul 10;195(8):927. doi: 10.1007/s10661-023-11500-6.
The diversity and abundance of the zooplankton community are affected by changes in physico-chemical parameters, trophic interactions, water level changes, and periodic mixing. In this study, the influence of environmental variables, water level changes, and periodic mixing on zooplankton distribution and abundance was seasonally studied for Lake Ardibo from October 2020 to September 2021 collected from 3 sites. Results on the physico-chemical variables indicated that all variables, except turbidity, varied significantly (p < 0.05) in all sampling seasons. A total of 33 zooplankton species were recorded, comprising 18 rotifers, 11 cladocerans, and 4 cyclopoid copepods. Zooplankton abundance significantly varied seasonally with peak abundance (4232.13 ind. L) recorded in the dry season and lowest numbers (402.42 ind. L) during the long rainy period. Redundancy analysis (RDA) results indicated that total phosphorus, ammonia, water temperature, silicon dioxide, and conductivity were the most significant driving forces for the seasonal successions in the abundance and distribution of zooplankton communities. Cyclopoid copepod abundance was significantly (p < 0.05) higher in the dry season, which could be correlated with the partial mixing (atelomixis) phenomenon that occurred during the dry period.
浮游动物群落的多样性和丰度受理化参数变化、营养相互作用、水位变化和周期性混合的影响。本研究于 2020 年 10 月至 2021 年 9 月期间，从 3 个站点采集了 Ardibo 湖的水样，季节性研究了环境变量、水位变化和周期性混合对浮游动物分布和丰度的影响。理化变量的结果表明，除浊度外，所有变量在所有采样季节均有显著差异（p<0.05）。共记录了 33 种浮游动物，包括 18 种轮虫、11 种桡足类和 4 种环足类桡足类。浮游动物丰度季节性差异显著，丰度最高（4232.13 个/L）出现在旱季，最低（402.42 个/L）出现在长雨季。冗余分析（RDA）结果表明，总磷、氨、水温和二氧化硅、电导率是浮游动物群落丰度和分布季节性演替的最主要驱动力。环足类桡足类丰度在旱季显著更高（p<0.05），这可能与旱季发生的局部混合（atelomixis）现象有关。
