MAHI

Mussel Assemblage Health Index (MAHI) is a bioassessment tool for evaluating the health of freshwater mussel assemblages, which allows inference about the overall health of the streams in which mussel assemblages occur. It is conceptually similar to the Index of Biotic Integrity (IBI), which typically is based on aquatic insect or fish assemblages. MAHI uses commonly collected mussel survey data to compute a score for four metrics, each reflecting a fundamental aspect of assemblage or population health (species loss, recruitment, abundance, and population growth), and the composite MAHI score is the unweighted mean of the four metric scores. All scores are scaled from 0–10, representing increasing health. Scores can be compared among streams throughout eastern North America regardless of stream size, biogeographic region, or other intrinsic factors, and it may be adapted to other regions. MAHI is a valuable tool for early detection of mussel declines, better understanding the causes of declines, and evaluating the effectiveness of conservation strategies and management actions. Details about development, calculation, evaluation of MAHI can be found in the publication below.

This application is an Excel file that allows users to input required data and returns individual metric scores, a composite MAHI score, and other information.