Oil spills and man made pollutants leap to mind at the mention of endangered sea life and toppled ecosystems, but unknown to most laypeople, an everyday event in the world of maritime transport is actually among the most significant threats to marine ecology today.

Without any of the widespread attention given to a toxic spill, cargo ships and other vessels move from port to port around the world and often quietly introduce non-indigenous species that can wreak havoc in their new habitats.