This video introduces phytoplankton - the base of the marine food web, the source of half of the oxygen on Earth, and an important remover of CO2 from the atmosphere. The video also explains how satellites are used to monitor phytoplankton and how warming waters and acidification negatively affect phytoplankton.

This narrated slide show gives a brief overview of coral biology and how coral reefs are in danger from pollution, ocean temperature change, ocean acidification, and climate change. In addition, scientists discuss how taking cores from corals yields information on past changes in ocean temperature.