Harmful algal blooms occur when algae, which form the base of the ocean food web, grow in massive numbers and produce toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. In this project you will learn how to use archived data from continuous monitoring stations on the Chesapeake Bay to study how water quality measurements (dissolved oxygen (DO), salinity, temperature, pH, turbidity, and total chlorophyll) change before, during, and after harmful algal blooms.