Lignite mining and stream channelization influences on aquatic macroinvertebrate assemblages along the Natchez Trace Parkway, Mississippi, USA

摘要

The article describes the effects of channelization on selected water quality parameters and benthic macroinvertebrate assemblages in four Big Black River (Mississippi, USA) tributaries crossing the Natchez Trace Parkway [U.S. National Park Service (NPS)]. Two of the streams were unchannelized (Little Bywy Creek and McCurtain Creek), and two were channelized (Big Bywy Creek and Middle Bywy Creek). Lignite mining occurs in the headwaters of Little Bywy Creek and Middle Bywy Creek. During this 3-year study, benthic macroinvertebrates were collected monthly from all four streams using Hester-Dendy Multiple plate samplers, and enumerated taxonomically and functionally. Hypotheses were tested using analyses of variance. Relationships were determined using multivariate analyses. Relative abundances of mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera) and aquatic beetles (Coleoptera) were associated with moderate to high conductivity, alkalinity, pH, and dissolved oxygen. Hellgrammites (Megaloptera), midges, blackflies, and mosquitoes (Diptera), crayfish (Crustacea: Decapoda) and leeches (Annelida: Hirudinea) were associated with lower values for these parameters. These patterns reflected seasonal rather than spatial variation (i.e., among the streams). Invertebrate assemblage composition was similar among the four streams with respect to functional groups. Invertebrate relative abundances in the two channelized streams were approximately half those of the unchannelized streams. Macroinvertebrate species richness was greater in unchannelized streams. Environmental indices categorized all four streams as having fair to good condition.