Darwin's Nightmare

For proof that upsetting the ecology can have dire consequences, see this 2004 documentary that chronicles what happened in Tanzania when the non-indigenous Nile Perch was introduced to Lake Victoria in the 1960s to combat over-fishing. The piscine predator devoured the native species, ruined the lake’s ecosystem, and has had a disastrous economic and social impact on the local economy, now dependent on exporting a commodity its impoverished people can’t afford.