Macroinvertebrate drift density in relation to abiotic factors in the Missouri River

Abstract

Changes in flow management to restore ecosystem health have been proposed as part of many restoration projects for regulated rivers. However, uncertainty exists about how the biota will respond to flow management changes. The objectives of this study were to estimate the relative importance of key abiotic predictor variables to aquatic macroinvertebrate drift densities in the Missouri River and to compare these results among reaches of the river. A multi-year, multi-location database of spring macroinvertebrate drift net sampling was used to develop relations between drift density and variables representing discharge, temperature, and turbidity in the Missouri River from Fort Randall Dam, South Dakota to the mouth of the Little Nemaha River, Nebraska. Multimodel inference using generalized linear mixed models and an information theoretic approach were used to estimate the relative importance of the predictor variables and the parameters. The results varied by reach. Discharge-related factors were more important at the upstream end of the study area, and turbidity was more important at the downstream end of the study area. Water temperature or degree days were also important predictors in the upstream reaches. The results below Gavins Point Dam suggest that increased macroinvertebrate drift densities are a response to reduced habitat and food availability. The results identify important variables for drift density that could be used in future experimental studies of flow manipulation for the Missouri or other large, regulated rivers.

Spatiotemporal variation in flow-dependent recruitment of long-lived riverine fish: Model development and evaluation

“…In each simulation year, initial prey biomass in each grid cell is randomly assigned on January 1st with a mean of 18.8 wet g m −2 (±2.2 SE), which was derived from field studies conducted near the study system (the Platte and Missouri Rivers, Hay et al, 2008;Whiles and Goldowitz, 2001; with a wet to dry weight conversion factor of 0.145 (Cummins and Wuycheck, 1971 …”

Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam

“…Aquatic ecosystems are essential for the development of human societies, offering goods and services of fundamental importance, such as water supply, flood control, transportation, and power generation (Hay et al, 2008;Arthington et al, 2010). However, rivers have suffered countless influences of human activities, primarily from waste releases, introductions of alien species, construction of barriers, and alteration of flow regimes (Agostinho et al, 2005).…”

“…The abiotic changes resulting from dams, reservoirs, and flow alterations can change important biotic parameters, including benthic macroinvertebrate Hay et al, 2008) and fish (Rinne et al, 2005;Pompeu et al, 2012) assemblages. The reduction of substrate heterogeneity reduces the diversity of available habitats for macroinvertebrates, decreasing their abundance and diversity (Patterson and Smokorowski, 2011).…”

“…Differences in drift densities may also vary by species and life cycle stage (Hansen and Closs, 2007). Macroinvertebrate drift is very important to aquatic ecosystem function, because it is a primary mechanism for the redistribution and colonisation of aquatic macroinvertebrates (Hay et al, 2008) and offers prey for predators such as fish (Flecker, 1992). Invertebrates downstream are affected by constant changes resulting from plant operations and may have different behaviours in the drift (Troelstrup and Hergenrader, 1990).…”

Macroinvertebrate community structure and its seasonal variation in the Upper Mississippi River, USA: a case study

“…Seasonal or other short-term temporal variation has been examined indirectly, if at all, in the recent large river studies we reviewed. Hay (2006) reported that total drift density in the Missouri River was positively correlated with degree-days. Also in the Missouri River, Grohs (2008) noted higher total richness in the summer and fall, but discriminatory power was limited by family-level identifications.…”