eChapter Name: A Study on Ichthyofaunal Diversity and Influence of Physico-chemical Parameters on Fish Species of the Maguri-Motapung Beel, Tinsukia District, Assam
9789358872057
eBook Name: LIMNOLOGY AND MARINE BIOLOGY
by Januka Sharma, Tribeni Hazarika
INTRODUCTION
The aquatic ecosystem is highly dependent on water quality and biodiversity. The water quality parameters play an important role in the biology and physiology of fish (Dhawan and Kaur, 2002). Fish communities are an important aspect of the aquatic ecosystem. Moreover, they also serve as an indicator of the quality of the aquatic ecosystem (Sharma et al., 2014). Ramsar Convention on wetlands in 1971, characterized wetlands as "Areas of Marsh, fen, peatland, whether natural or artificial, permanent or temporary with water that is static or flowing, brackish or salt, including areas of marine water the depth of which at low tide should not exceed". At the surface, freshwater serves as a habitat for numerous species and comprises a substantial portion of Earth's biological diversity. Wetlands cover approximately 6.4% of the Earth's total surface area. Being a large biodiverse region, India accounts for 11.72% of the world's fish diversity and 40% of fish live in freshwater ecosystems (Kar et al., 2006, Balasubramanium, 2017). Fish are key species that determine the distribution and abundance of other organisms and have a significant impact on the ecosystem and are considered good indicators of water quality in the ecosystem (Moyle and Leidy, 1992). Assam, located in the northeastern region, possesses extensive and diverse freshwater resources, earning it recognition as one of the richest biodiversity sites in India. There are 2,500 species of fish in India; 930 of them live in fresh water and 1570 in the sea (Kar, 2003). The entire northeastern region, including Assam, has large and diverse freshwater resources and is considered one of the richest biodiversity hotspots of India. The NE region has unique topographic conditions and is blessed with large and varied water resources in the form of rivers (19,150 km); swimming pools (23,792ha); lakes and marshes (143,740 ha); ponds and mini-dams (40,808 ha) and shallow spawning systems paddy with fish farming systems (2780 ha) (Mahanta et al., 2003). This region of the country is very diverse in terms of fish. So far, 267 freshwater fish species belonging to 114 genera 38 families and 10 orders have been reported from the region (Mahanta et al., 2003). A total of 266 species belonging to 114 genera under 38 genera and 10 orders have been reported from the Northeast including Assam (Sen, 2010). A survey of the fish fauna of the Brahmaputra in Assam revealed 41 commercially important species (Talwar and Jhingran, 1991). Assam has 1,392 beels in over 100,000 hectares, which constitutes 61 percent of the state's lentic water supply. Water is one of the most important compounds in the ecosystem. Better water quality is characterized by its physical, chemical and biological characteristics.