Wetlands play an important ecological role by providing shelter and habitat for diverse fish species, migratory birds, macrophytes and other aquatic organisms. Hydrological connectivity with the main river channel has a critical role in fish diversity and production in floodplain wetland. The present study showed the seasonal hydrological alteration on fish species distribution in Ansupa wetland, connected with tropical river Mahanadi, India. The river discharge showed a variation from 4549 cusec during lean season (April) to 204716 cusec during monsoon (August). It has been recorded that water flows/discharge above 200000 cusec only, inundate the wetland resulting in exchange of free flows of fish species and nutrients. The study period for the fish species diversity was undertaken during 2017-18. A total of 46 fish species were observed under the orders Cypriniformes (18), Perciformes (12), Siluriformes (7), Synbranchiformes (2), Cyprinodontiformes (1), Clupeiformes (1), Beloniformes (1), Osteoglossiformes (1), Mugiliformes (1), Anguilliformes (1) and Tetraodontiformes (1). According to the conservation status of the International Union for Conservation of Nature, four species Parambassis lala, Ompok bimaculatus, and Anguilla bengalensis are in the category of Near Threatened. Analysis showed that taxonomic distinctness is more during winter than the monsoon and pre-monsoon, indicating monsoon could play a significant role in the fish species recruitment through river connectivity. Climatic data was analysed for a period of 34 years and indicated that an increment of 0.20C in water temperature and average increase of 129mm rainfall at the study site. This slight increase in rainfall over the years could be one of the factors responsible for the fish recruitment in the Ansupa wetland, through river connectivity underlining the importance of flood for wetland fisheries recruitment and sustainability.

中文翻译：

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气候变化下河流流向维持洪泛区湿地渔业的动态：案例研究

湿地通过为各种鱼类、候鸟、大型植物和其他水生生物提供庇护和栖息地，发挥着重要的生态作用。与主要河道的水文连通性对洪泛区湿地的鱼类多样性和生产具有关键作用。本研究显示了与印度热带河马哈纳迪河相连的安苏帕湿地鱼类物种分布的季节性水文变化。河流流量从淡季（4 月）的 4549 立方秒到雨季（8 月）的 204716 立方秒不等。据记载，仅超过 200000 立方秒的水流量/排放量会淹没湿地，导致鱼类物种和营养物质的自由流动交换。鱼类物种多样性的研究期在 2017-18 年间进行。共观察到 46 种鱼类，依次为鲤形目 (18)、鲈形目 (12)、鲶形目 (7)、合鳃形目 (2)、鲤形目 (1)、鲱形目 (1)、白鳖形目 (1)、骨舌形目 (1) , Mugiliformes (1), Anguilliformes (1) 和 Tetraodontiformes (1)。根据国际自然保护联盟的保护状况，Parambassis lala、Ompok bimaculatus 和 Anguilla bengalensis 四个物种属于近危。分析表明，与季风和季风前相比，冬季的分类差异更大，表明季风可能通过河流连通性在鱼类物种补充中发挥重要作用。分析了 34 年的气候数据，表明增量为 0。研究地点的水温上升了 20 摄氏度，平均降雨量增加了 129 毫米。多年来降雨量的轻微增加可能是安苏帕湿地鱼类补充的因素之一，通过河流连通性强调了洪水对湿地渔业补充和可持续性的重要性。