Program Overview
Indiana has hundreds of public lakes. Most in northern Indiana were naturally formed, while most in central and southern Indiana are man-made. These lakes are ecologically valuable resources that provide habitat for many species and abundant recreational opportunities.
The goal of the DNR Status & Trends Program is to provide a study design that accurately describes the current condition of Indiana lakes and monitors changes over time. Evaluations of native fish communities, habitat, and water quality form the foundation of the program. Dissolved oxygen and water temperature profiles are completed each summer to quantify warm, cool, and coldwater habitat availability. Cool and coldwater habitat are necessary for native species such as Northern pike and Cisco to thrive in lakes. Aquatic vegetation is assessed using standardized vegetation surveys and hydroacoustic mapping.
Fish Community
Standardized fish community surveys are completed each May and June using a randomized sampling schedule. Fisheries biologists collect fish using trap nets, gill nets, and nighttime electrofishing. All three pieces of equipment allow fish biologist to collect a variety of fish species to assess the composition of fish communities.
Captured fish are identified and measured and are then immediately returned to the lake. The long-term commitment to these fish community surveys provides fisheries biologists with the information necessary to detect changes to native fish communities over time. This includes changes to ecologically important native species, such as Northern pike, cisco, white sucker, lake chubsucker, bowfin, and many others. Since 2010, biologists have completed fish community surveys at hundreds of natural lakes (i.e., glacial lakes) and man-made lakes (i.e., reservoirs). The results of these fish community survey results are available using the interactive dashboard below.