Effect of abiotic factors on the diversity and abundance of aquatic macroinvertebrates in the East and West Branches of the Maple River, Michigan, USA

Abstract

Streams are home to a wide variety of aquatic organisms including fish and benthic macroinvertebrates. Variance in diversity and abundance of macroinvertebrates in stream ecosystems is influenced by water chemistry and substrate availability. Different substrates provide macroinvertebrates with varying habitats, protection, and resources. Four distinct sites on the East and West branches of the Maple River around Pellston, MI were sampled and studied to examine the combined effects of abiotic factors on macroinvertebrate diversity and abundance. At each site, three substrates (cobble, gravel, and sand) were studied. Rocky riverbed substrates (i.e. gravel and cobble) contained greater numbers and more diverse macro invertebrate families than sandy substrates. Stable isotope analysis of the water from each site showed a correlation between the abundance of individuals and groundwater concentration but did not show a correlation between diversity of families and groundwater concentration.