Padma Multipurpose Bridge Project

3.2 Ecological ResourcesFigure 3-19: Bathymetry of the Padma in 2008 and 20093.2.1 State of Biodiversity40. Traditionally biodiversity in Bangladesh has been identified and described in three levels (e.g.genetic, species, and ecosystem), in this study we only discussed on ecosystem and species levelbiodiversity of the country and the project area.41. Bangladesh was once rich in wildlife species and is an important transition zone betweenIndo-China, the Himalayas and the rest of the Indian subcontinent. The tropical moist forests werebotanically amongst the richest in the Indian subcontinent, and they also supported the greatestdiversity of mammals and a high diversity of birds. In recent times, although the endemism is low andthe species richness is relatively large for the small area of Bangladesh, the population size of most ofthe species has declined drastically. Eighteen species of wildlife are now extinct from Bangladesh.Among them are several internationally threatened species such as the three species of Asianrhinoceros, and also the banteng, nilgai, swamp deer, pink headed duck, Bengal florican and muggercrocodile. The project area has a wide variety of biodiversity, in which the biota encountered duringecological survey is compared with the whole country data. Table 3-12 shows that 380 vertebrates(approximately one quarter of the Bangladesh species) are found in the project area and that thesurvival status of 53 of them, based on the IUCN Red Lists, is in a critical stage. The role of the areafor migrating birds (winter visitors) is demonstrated by the observation of 24 species.Table 3-12: Biota of Bangladesh and in the project areaSpecies inStatus (Bangladesh/Project Area)Group Bangladesh/ Criticallyproject area EndangeredEndangered Vulnerable TotalFishes 708 (158) 12 (6) 29 (14) 17 (9) 58 (29)Amphibians 22 (15) 0 (0) 3 (3) 5 (4) 8 (7)Reptiles 126 (28) 13 (0) 28 (3) 22 (3) 63 (6)Birds 628 (157) 19 (1) 20 (1) 8 (1) 47 (3)Mammals 113 (22) 21 (1) 15 (5) 7 (2) 43 (8)Plants 3,454 (138) 1 (0) 106 (21) 21 (0) 106 (21)Source: IUCN Bangladesh, 2000 and the Consultant Ecological Survey, 2009-2010.3.2.1.1 Ecosystem diversity42. Within a relatively small geographic boundary Bangladesh enjoys a diverse array ofecosystems. Temperature, rainfall, physiographic variations in soil and different hydrologicalconditions play vital roles in country’s diverse ecosystems. In national level, twenty five bio-ecological3-23