Thirty-six species of macroinvertebrates live in Fishing Creek. The highest level of macroinvertebrate biodiversity on upper Fishing Creek is near Grassmere Park while the lowest is in Benton. The number of these organisms per square meter on Fishing Creek ranges from under 200 in Benton to nearly 400 halfway between Coles Creek and Benton. The highest density of them in the watershed occurs at West Creek where there are between 600 and almost 900 per m2 and the lowest density occurs at a site on East Branch Fishing Creek, where there are approximately 100 per m2.