Wetland Health Evaluation Program (WHEP)

Why Wetlands?
What is an IBI?
Invert. Sampling (spineless critters)
Vegetation Sampling
Get Involved
Training and Events
Resources and Presentations
Wetlands Monitored
Wetland Sites Map (Dakota County)
WHEP Reports and Data
Frequently Asked Questions
Contact Us
Index of Biological Integrity (IBI)
The Index of Biological Integrity, or IBI, is a scoring system used to measure strong responses to human disturbance, or pollution, in wetlands. WHEP focuses on two biological communities: plants and macroinvertebrates (small organisms in the water without a backbone: insects, leeches, snails, etc.).
The Minnesota Pollution Control Agency selected a variety of metrics (measurements) which focus on those organsims which best reflect wetland quality or health. Each metric is evaluated based on the identified specimens and their abundance. They reflect organism presence and relative abundance. Depending on the result of the metric, each is awarded a score of one, three or five. The scores for each metric are combined to calculate a total score, this is the IBI.  The higher the score, the higher the likelihood of a healthy wetland. 
The IBI score is then converted to an overall rating to give the wetland a qualitative description (poor, moderate, excellent). A wetland described as poor has a minimal variety of organisms and a large number of them would likely not be sensitive to pollution.  A wetland of excellent quality would have a higher variety of organims and contain those species that are more sensitive to human disturbance or pollution.   
The two IBIs (macroinvertebrates and vegetation) have slightly different ratings based on the scoring range. This is due, in part, to the number of metrics evaluated in each IBI; six for the macroinvertebrate and seven for the vegetation IBI.
Refer to the links below for a complete list and description of the metrics used in the macroinvertebrate and vegetation IBIs.