Why Was the near Extinction of All Ocean Plankton in the Permian

Multiple Choice

Why was the near extinction of all ocean plankton in the Permian mass extinction so devastating to marine species?

A) Plankton are the base of aquatic food chains.
B) Plankton provide oxygen for other aquatic species.
C) Without plankton sequestering carbon, an enhanced period of global warming caused ocean temperatures to increase.
D) The dead plankton smothered coral reefs, killing them, which was a critical loss of nursery habitat for most marine species.