Plankton are important members of the aquatic food web. Plankton includes algae (microscopic plants) and zooplankton (tiny shrimp-like animals that eat algae). Plankton provide food for fish and insects.
Additional information regarding algae can be found using the links below:
Zooplankton Factsheet - information about freshwater zooplankton.
Toxic Algae Poster - a poster, suitable for enlarging and printing, that provides tips for avoiding exposure to algal toxins. Source: MN Pollution Control Agency.