Ecological and anthropogenic covariates ... - GANGAPEDIA

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GENERAL INTRODUCTION Humans have preferentially settled along freshwater resources, and subsequently, freshwater ecosystems and species have suffered from multiple and on-going stresses from use by humans (Revenga et al 2005). Consequently, species diversity of inland waters is among the most threatened of all ecosystems and global freshwater biodiversity is declining at far greater rates than is true for even the most affected terrestrial ecosystems (Sala, 2000). The gharial (Gavialis gangeticus, Gmelin, 1789), endemic to the Indian subcontinent, was once common in the river systems of Pakistan, northern India, Bangladesh, Myanmar, Bhutan and Nepal (Whitaker and Basu, 1983; Whitaker, 1987, 2007; Hussain, 1999, 2009). However, they are now restricted to a few, scattered locations in India and Nepal (Whitaker, 2007). The gharial, is becoming increasingly rare due to land-use changes, reduction in water flow, modification of river morphology, loss of nesting sites, increased mortality in fishing nets and egg-collection for consumption (Whitaker, 2007; Hussain, 2009); and is especially at risk from flow regulation because it prefers fast-flowing river habitats, which are prime sites for dams (Dudgeon, 2000). The Chambal river population is the largest contiguous and most viable population and has been the focus of conservation and restocking programmes. In recent times it has suffered from increasing disturbance from extractive activities and is under severe threat from hydrological modifications due to dam and reservoirs and diversion of river water for irrigation. 1
In the face of increasing proposals for water extraction and impoundments on the Chambal, and nation-wide river linking aspirations, it is critical that species requirements be understood and flow regimes be restored. Bunn & Arthington (2002), illustrate how flow is a major determinant of physical habitat in streams, which in turn is a major determinant of biotic composition; that aquatic species have evolved life history strategies primarily in direct response to the natural flow regimes; that maintenance of natural patterns of longitudinal and lateral connectivity is essential to the viability of populations of many riverine species; and that the invasion and success of exotic and introduced species in rivers is facilitated by the alteration of flow regimes. Information on the effects of habitat attributes (availability and profile of basking and nesting sites; water flow and quality; channel depth and width, etc.); biotic factors (prey density and diversity, co-predators, etc) and human disturbances (impact of dams, barrages, canals, pollution, excessive water extraction, fishing, sand-mining, riverbed cultivation, livestock presence, etc.) on gharial distribution and abundance are either scant or completely lacking, and thus are an impediment to effectively understand the conservation needs of the species. Literature Cited Bunn, S.E. and A.H. Arthington, Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity, Environ. Manage. 30 (2002), pp. 492– 507. 2
Page 1 and 2: Ecological and anthropogenic covari
Page 3 and 4: variable data like river discharge,
Page 5: Table of Contents EXECUTIVE SUMMARY
Page 9 and 10: Chapter 1 Ecological and Anthropoge
Page 11 and 12: Introduction Humans live disproport
Page 13 and 14: Despite the release of over 5000 yo
Page 15 and 16: its 523 km run, the river passes th
Page 17 and 18: sites considered favourble based on
Page 19 and 20: correction factor for the float mea
Page 21 and 22: Variable (type) Measurement Details
Page 23 and 24: interpolation deriving from regiona
Page 25 and 26: the effects of covariates measured
Page 27 and 28: We compared Zero-Inflated Poisson (
Page 29 and 30: Assessing changes in habitat availa
Page 31 and 32: Figure 6: Box-and-whiskers plots co
Page 33 and 34: Occasion 1: Residual mean deviance
Page 35 and 36: Occasion 3: Residual mean deviance:
Page 37 and 38: Discussion Humans have preferential
Page 39 and 40: Tucker et al. (1997) report that pr
Page 41 and 42: once caught in the net are wary of
Page 43 and 44: Bustard, HR and LAK Singh. 1977. St
Page 45 and 46: Hutton, J. 1989. Movements, home ra
Page 47 and 48: Oliver, M.A., R. Webster. 1990. Kri
Page 49 and 50: Chapter 2 Photographic identificati
Page 51 and 52: Hussain, 2009); and is especially a
Page 53 and 54: data also enables the estimation of
Page 55 and 56: A 600km stretch of the Chambal Rive
Page 57 and 58:
Marked animals were accorded no exc
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Single-crested region Figure 2: Lat
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A B C Capture: 07.02.2010 Figure 1.
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(Nichols, 1992). Since gharials are
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and Ross, JP. 2007. Gavialis ganget
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Mazzoil M., McCulloch S.D., Defran
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GENERAL CONCLUSION Humans have pref
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APPENDIX - 1 Figure 1: Scatter plot
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Figure 2: Scatter plots representin
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Page 77 and 78:
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Ecological and anthropogenic covariates ... - GANGAPEDIA

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