Limnologists collect and analyze samples of surface water, wastewater and groundwater throughout Iowa. This requires examining the physical, chemical and biological characteristics and processes of aquatic systems and their watersheds. The data from their work is used to assess long-term trends in water quality throughout the state.

Staff are based in both the Hygienic Laboratory's Coralville and Ankeny facilities. They devote most of their time to sampling Iowa's surface waters (usually rivers and streams) and evaluating both water quality and the impact of human activity. The environmental specialists in the Limnology section are among the very few taxonomic experts in the Midwest who identify, describe and classify organisms.

Mark Johnston, environmental analyst, collects an insect on a branch from the Cedar River in eastern Iowa. Limnologists monitor aquatic life in the state's waterways to gauge the environmental health of the water.

FY13 achievements:

Overall sample load in the Limnology section increased 3.4 percent from fiscal year 2012 to fiscal year 2013. The number of samples for identification of aquatic organisms to the lowest practical taxon increased by 68.5 percent.