Oppong Samuel K, Nsor Collins Ayine, Buabeng Gabriel Kwabena
Department of Wildlife and Range Management, Faculty of Renewable Natural Resources, Kwame University of Science and Technology, Kumasi, Ghana.
Department Forest, Resources, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Open Life Sci. 2021 Apr 8;16(1):336-353. doi: 10.1515/biol-2021-0040. eCollection 2021.
Aquatic macro-invertebrates play a vital role in the food chain of river ecosystem at several trophic guilds and consumer levels, and are used as biomonitoring tools for aquatic ecosystem health. However, hydrologic conditions of these ecosystems have been severely altered because of the increase in urban development and agricultural expansion. This study examined benthic invertebrate response to processes that structure their community in the Wewe River, segmented into intact, medium, and severe condition zones. We sampled in 100 stations in a period of 4 months in the wet (June-September, 2019) and 3 months in the dry (January-March, 2020) seasons. Geometric series, rarefaction, and Hill numbers models were used to quantify invertebrate assemblages, while ordination technique, canonical correspondence analysis, was used to evaluate the influence of predictive factors on their assemblages. A total of 2,075 individuals belonging to 20 family taxa were registered. There was no significant difference in benthic assemblages between the dry and wet seasons. Predictive factors accounted for 47.04 and 50.84% variances, respectively. Taxa distribution patterns differed significantly only in the severely disturbed zone during the wet season. Neptidae, Libellulidae, and Chironomidae were the most abundant taxa, indicating their broad range habitat preference and their ability to adapt to seasonal changes. Asellidae and Perlidae were the least detected, suggesting their sensitivity to elevated levels of some water quality parameters. The findings highlight the threats to the benthic community and overall functional state of the Wewe River, with the need to consider the proposed conservation interventions indicated in this study.
水生大型无脊椎动物在河流生态系统的食物链中，在几个营养类群和消费者层面发挥着至关重要的作用，并被用作水生生态系统健康状况的生物监测工具。然而，由于城市发展和农业扩张的增加，这些生态系统的水文条件已被严重改变。本研究调查了韦韦河中底栖无脊椎动物对构建其群落的过程的反应，该河流被划分为完整、中度和严重状况区域。我们在2019年雨季（6月至9月）的4个月和2020年旱季（1月至3月）的3个月内，在100个站点进行了采样。使用几何级数、稀疏化和希尔数模型来量化无脊椎动物群落，同时使用排序技术——典范对应分析，来评估预测因素对其群落的影响。总共记录了属于20个科类群的2075个个体。旱季和雨季的底栖群落没有显著差异。预测因素分别解释了47.04%和50.84%的方差。仅在雨季的严重干扰区域，类群分布模式存在显著差异。扇蟌科、蜻科和摇蚊科是最丰富的类群，表明它们具有广泛的栖息地偏好以及适应季节变化的能力。线蚓科和石蝇科的检出率最低，表明它们对某些水质参数升高较为敏感。研究结果突出了韦韦河底栖群落和整体功能状态面临的威胁，有必要考虑本研究中提出的保护干预措施。
