The health of wild fishes can be used as an indicator of aquatic ecosystem health. Necropsy-based fish health assessments provide documentation of visible lesions or abnormalities, data used to calculate condition indices as well as the opportunity to collect tissues for microscopic evaluation, gene expression and other more in-depth analyses.
Blazer, V. S., Walsh, H. L., Braham, R. P., Smith, C. Necropsy-based Wild Fish Health Assessment. J. Vis. Exp. (139), e57946, doi:10.3791/57946 (2018).