Putting India's Large-Scale Interbasin Water Transfer Project in Fish Terms

Conflict between resource use and the conservation of ecosystems will only increase as a developing population puts increasing pressure on nature to supply basic rights, most importantly the predictable access to water.  With the uncertainty in timing, amount, and distribution of precipitation under a changing climate, large-scale interbasin water transfer (IBWT) projects are an increasingly attractive solution to solving water distribution and supply issues.  Balancing ecosystem requirements, societal demands, politics, and economics is a monumental task in assessing the feasibility of such large-scale projects, and ecological consequences are often given the least attention.  Under an IBWT project, river connectivity is restructured via the addition of canals.  Such projects are expected to drastically affect the stability and identity of communities living in the hierarchically-structured river networks.  We apply a neutral metacommunity model to both simulated and empirical data to show how freshwater fish communities are likely to be impacted by this project.  We find that, when using simulated datasets, the addition of the canals facilitates the spread of common species at the expense of rare species, allowing them to become even more widespread. In many scenarios, this lowers the total number of species in the system.  We compare our simulation modeling results with empirical data representing 460 freshwater fish species in river basins across peninsular India.