Snakes and Ladders: Navigable Waterways as Invasion Corridors

This chapter describes how the economic arguments in favor of the development of inland waterway infrastructure should not obscure their significant long-term cost to the environment. Most inland waterways are no longer pristine: watershed engineering, discharge of agricultural, industrial and domestic wastes, and power plant cooling water have contributed to varying impairments of the environment and harmed the native biota, which leaves it vulnerable to invasion or degradation. Reconstruction of existing navigable waterways and constructions of new canal systems expedite the range expansion of taxa within the interconnected watersheds, which promotes both homogenization of faunas and secondary and tertiary invasions. The rise in sea-river transport in the inland waterways transport market will enhance the spread of alien taxa that comes with transoceanic shipping. With ample evidence that inland waterways serve as major invasion corridors, environmentally-considerate waterway engineering should include barriers that might preclude future invasions.