Benthic invertebrate communities are good indicators of acidification which is caused by acidic pollution from precipitation and acids leaching from the surrounding soils. Benthic invertebrates are easily suited to biological monitoring as they are common, widespread and easily sampled. This method is based on the principle that different benthic invertebrates have different tolerances to acidification.
This method uses the lake acidification macroinvertebrate metric (LAMM). The method statement linked below and its associated summary are relevant for the first and second river basin planning cycles.