Choose a specific ecosystem (eg a coral reef, a desert, a rainforest) and briefly describe a situation where human intervention has significantly altered it (either for the better or the worse). Remember to describe the ecosystem both before and after the changes and explain the factors that have caused the transformation (examples would include logging companies clearing large areas of forest or the introduction of a treatment plant that reduced the amount of raw sewage piped into the sea).
Discuss how far you believe human beings should go to protect current ecological systems (if at all) and whether you think there is ever a time when natural ecology should be sacrificed for human needs.
Be sure to properly cite any outside sources you use.