The National Park Service has produced a high-quality presentation on the halibut population of Glacier Bay, Alaska. It takes the viewpoint of the marine biologists or rather, ichthyologists, who have been studying the adaptations,...

There is more about the Milky Way that scientists don't know than what they do know—that leaves a lot to discover! A thorough lesson presentation explores the components of the Milky Way Galaxy and their behaviors. 

The vocabulary used in this presentation on salt marshes makes it most appropriate for high school or college level ecology classes. The content, however, is relatively simple; It introduces the flora and fauna of this type of ecosystem....