Effects of Local Land Use on Physical Habitat, Benthic Macroinvertebrates, and Fish in the Whitewater River, Minnesota, USA

Abstract

Best management practices (BMPs) have been developed to address soil loss and the resulting sedimentation of streams, but information is lacking regarding their benefits to stream biota. We compared instream physical habitat and invertebrate and fish assemblages from farms with BMP to those from farms with conventional agricultural practices within the Whitewater River watershed of southeastern Minnesota, USA, in 1996 and 1997. Invertebrate assemblages were assessed using the US EPA's rapid bioassessment protocol (RBP), and fish assemblages were assessed with two indices of biotic integrity (IBIs). Sites were classified by upland land use (BMP or conventional practices) and riparian management (grass, grazed, or wooded buffer). Physical habitat characteristics differed across buffer types, but not upland land use, using an analysis of covariance, with buffer width and stream as covariates. Percent fines and embeddedness were negatively correlated with buffer width. Stream sites along grass buffers generally had significantly lower percent fines, embeddedness, and exposed streambank soil, but higher percent cover and overhanging vegetation when compared with sites that had grazed or wooded buffers. RBP and IBI scores were not significantly different across upland land use or riparian buffer type but did show several correlations with instream physical habitat variables. RBP and IBI scores were both negatively correlated with percent fines and embeddedness and positively correlated with width-to-depth ratio. The lack of difference in RBP or IBI scores across buffer types suggests that biotic indicators may not respond to local changes, that other factors not measured may be important, or that greater improvements in watershed condition are necessary for changes in biota to be apparent. Grass buffers may be a viable alternative for riparian management, especially if sedimentation and streambank stability are primary concerns.

Overview and application of the National Aquatic Ecological Monitoring Program (NAEMP) in Korea

“…This approach has some considerable benefits compared to conventional methods (i.e., chemical criteria analysis) for evaluating water quality. For example, biological approaches can detect factors such as low-level and non-point source pollutants (Barbour et al, 1999), physical habitat alteration (Kutka and Richards, 1996;Nerbonne and Vondracek, 2001), and long-term ecosystem effects of anthropogenic influences (Barbour et al, 1999). Biological criteria can be considered as ecological benchmarks, and various biological indices are assumed to be sensitive to environmental changes and disturbances induced mostly by humans (Davis and Simon, 1995;Simon, 1999).…”

Macroinvertebrate prey availability and food web dynamics of nonnative trout in a Colorado River tributary, Grand Canyon

“…Stream gradient was measured with a laser transit. Remaining variables were measured with a transect method similar to that of Nerbonne and Vondracek (2001) (Grant 1999). Prey energy densities for invertebrate taxa were from Cummins and Wuycheck (1971).…”

Headwater stream response to grassland agricultural development in New Zealand

“…Alterations to nutrient loading (Cooper & Thomsen 1988;Biggs & Close 1989;Allan et al 1997), solar energy flux and organic matter inputs (Hicks 1997), hydrology (Davies-Colley 1997), and sediment inputs (Rothrock et al 1998;Nerbonne & Vondracek 2001;Zweig & Rabeni 2001) have been implicated as factors that influence community and ecosystem parameters such as biodiversity, nutrient cycling, energy flux, and food-web characteristics. Identification of the suite of changes to inputs to stream systems and how systems respond to these changes is important if we are to make further progress in mitigating the effects of land use practices on aquatic systems.…”