Trophic relationships and ecosystem functioning of Bakreswar Reservoir, India

Reservoirs are artificial water bodies having social application and hybrid characters of both river and lake. Thorough analysis of water quantity and quality is necessary to ensure the health of these ecosystems, as they are considered one of the major water sources in developing countries. Biological subsystem of reservoirs consists of both autotrophs and heterotrophs in the open zone and littoral zone. These components are critical for freshwater aquatic food webs. Bakreswar reservoir has been selected as the current study site. Static model representing ecosystem trophic structure is developed through Ecopath with Ecosim software and is analysed to obtain idea about the ecosystem functioning and functioning. This reservoir is found to be approaching maturity but with vulnerabilities being present as is evident from the studies of ecosystem attributes, transfer efficiencies, mixed trophic impact, niche overlap and other attributes. Good assemblage of biota like macrophytes, zooplankton etc. is observed, thus presenting some diversity in the food web. Based on the primary production to respiration ratio, this system can be categorized as a moderately mature and healthy ecosystem but is vulnerable to perturbations as is evident by low values of connectance index and system omnivory index. Comparatively low Finn cycling index indicates that this system is approaching maturity but is vulnerable. With a pedigree index of 0.459, the model is well suited for the study site. The knowledge thus obtained for this reservoir can be utilized to form proper management strategies to facilitate successful conservation management and proper resource utilization.