COMPARATIVE STUDY OF FISH PRODUCTION IN RELATION TO PERIPHYTIC STRUCTURE IN FLOODPLAIN WETLAND ECOSYSTEMS

Periphytic communities are a major component of wetland ecosystem which are influenced by several ecological factors like light, temperature, nutrients, and space availability in the water. Immense potential does exist towards increase in fish production about 3 times through aquaculture based on periphyton. Present investigation was carried out in two floodplain wetlands having unique characteristics of both open (Amda beel) as well as close (Suguna beel) system for two consecutive years during October, 2018 to September, 2020. Periphytic community, Soil and water quality and fish production of the beels were estimated and assessed in monthly interval during the study. Maintenance of a healthy aquatic environment and production of sufficient fish food organisms in the water bodies are two basic factors of primary importance for boosting fish production. A mixed population of diversified fauna constitutes the periphytic population of the investigated ecosystems. The values of species diversity clearly indicated that both the wetlands were favourable for harbouring balanced population of the periphytic fauna. In this paper an attempt has been made to study comparative status of fish production in relation to periphytic structure in unique ecosystems where flowing and stagnant conditions were compared. From the point of view of fish crop, the Suguna was more productive as indicated by the annual fish yield being 1601.01 - 1688.58 kg ha-1yr-1. In this beel the major carp contributed maximum towards production (54.17 - 87.53 %). The per cent contribution of miscellaneous group of fishes in Suguna was 9.59-45.83 during the study. The annual average fish production of the Amda fluctuated between 353.76 – 442.85 kg ha-1yr-1. The major contributor to the fish catches were the miscellaneous species (about 62%). The carps contributed 6.64 – 68.95% of the fish production in Amda. The fish production in the open beel was found to be very low in spite of higher biomass of periphytic community was mainly due to higher siltation rate, poor management, weed infestations and nutrient imbalances, and many more issues related with the river connectivity leading to natural fluctuations in the water level in the beel. The situations in these beels are complex and needs the balance to maintain sustainable fish production and associated livelihood in equilibrium with socio-environmental ethics.