ABSTRACT
One of the listed Ramsar sites is Tanguar haor wetland which provides numerous ecosystem services with significant number of biodiversity and contribution to the national economy of Bangladesh. In recent years, anthropogenic activities and natural process are causing adverse effects by decreasing ecosystem services. The aim of this study was to identify ecological threats and level of depleting ecosystem services due to anthropogenic activities. Data were collected through household survey (HHS) from 270 respondents by cluster sampling to achieve the specific objectives. Statistical techniques had been used to analyze data using SPSS software. The findings reveal that water is the most severely vulnerable elements (scored 885), and biota (842), soil (446), air (425) respectively. Local people perception on vulnerability level of environmental elements was found similar based on education level and occupation compared to overall ranks. The analysis of change percentage revealed that major trending human activities (which were more responsible for water quality change) were land use change, fishing activity, fertilizer and pesticides usage, multipurpose use of haor water, extensive resource extraction and agriculture practices at Tanguar haor. At the same time, amphibians (41.1%) and water quality (36.3%) are the most impacted resources through human activities. The study suggested that awareness formation for conservation of fish, birds, swamp forest, prohibit water pollution, alternate income generating opportunities, ecosystem friendly tree plantation are required with sustainable way to enrich the ecological diversity in Tanguar haor.
Key words: Conservation, ecosystem, Tanguar haor, human activities, resource.

Introduction

The freshwater wetland, Tanguar haor offers social, economic and environmental benefits through helping community’s livelihoods and creating income source (Khan, 1993; Islam, 2010). This wetland also provides food, fuel, fodder, genetic resources, flood regulation, hydrological services, aesthetic, spiritual, learning & knowledge, recreational use, photosynthesis and primary production (IUCN, 2015). At the same time, each of the haor basins is key elements of complex hydrological, biological and ecological system, supporting a significant assemblage of rate and vulnerable species of plants and animals along with cultural services (Bevanger et al., 2001; Fischlin et al. 2007; Kibria, 2015). It has been estimated that a total of 141 fish species, 11 amphibians, 34 reptiles (6 turtles, 7 lizards and 21 snakes), 206 birds and 31 mammals occur in this haor (Nishat, 1993; Karim, 1993). The estimated fish stock of Tanguar Haor is 6,701 tons (Ahmed, 2015). These ecological components have been impacted over the years which has a strong relationship with human activities. Haor areas are threatened due to various causes, such as population pressure, demand in markets, unplanned infrastructures (IUCN, 2009). At the same time, government policies and institutions that oversee access to, and management and exploitation of, wetlands have weakened conventional wetlands customs and practice, leading to exhausted ecosystems and poverty. In a study, land use change had been highlighted as a key human-induced effect on ecosystem services (Uddin et al., 2015). It is important to quantify the impacts on haor ecosystem services for human activities to make a proper sustainable way to conserve and protect Tanguar haor ecosystem. Because, during the last