The coastal ecosystem of the Bay of Bengal (BOB) is described using a mass balance model of trophic interactions, in order to understand the effects of Set Bagnet (SBN ) on the ecosystem ecosystem. The BOB model included an area of ​​24,000 km2 and had 14 functional ecological groups including 13 living groups and one dead (debris) group. The result showed that all consumers had ecotrophic efficiency (EE) >0.90, indicating that consumers were heavily exploited in the system. The fishery operated at an average trophic level of 2.45. The SBN fishery was characterized by higher fishing mortality rates and large omnivore indices for most commercially exploited demersal and pelagic groups. For this fishery, the total primary production requirement for sustainable capture was estimated at 15.11%. However, Ecosim simulation results made it clear that key resources such as small demersal, small and medium pelagic shrimp, and penaeid shrimp were likely to show rapid declines in yields within 5 years due to increased fishing effort and pressure. In contrast, the yields of palemonids and sergestite shrimps showed an increasing trend as they appear to be able to sustain the high fishing pressure as long as their predators are also caught. Furthermore, cephalopods, which are a non-target group in this fishery, will also likely increase yields over time. The two groups most drastically affected in both fisheries are probably sharks and small demersal sharks. The continued increase in SBN fishing effort has proven to be responsible for a rapid decline in most commercial marine resources and a severe effect on BOB ecosystem functioning. Keywords: Bay of Bengal, Set Bagnet, High fishing pressure, yields, Ecosim.1. IntroductionBangladesh has v...... half of the paper...... mass (B) has been run until the input equals the output for each box. Both gross efficiency and ecotrophic efficiency for all functional groups should be less than one. To achieve mass balance for all groups, adjustments to diets were initially made as the feeding habits of some organisms are highly labile and mainly depend on the food sources available in the ecosystem. The second step involved manual biomass adjustments for several groups estimated by applying the weighted average method from multi-year survey data. In Ecopath, trophic levels are the calculated output or results. If they do not conform to expectations, you can check the diet composition of the input data. In case of doubts about the trophic levels of fish, for example, it is possible to check the trophic levels of identical or similar species with FishBase.