A single quart of motor oil can contaminate up to 2 million gallons of drinking water.
Balloons, warfare, people overpopulating themselves, sewage, noise, sonar, airplane contrails are all examples of pollution and contamination.
One of the many, many species that is suffering greatly is the Manatee. Join the PEER campaign to help protect the Manatees! PEER stands for Public Employees for Environmental Responsibility http://www.peer.org/campaigns/wildlife/manatees/index.php