Fish Community Response to Habitat Alteration: Impacts of Sand Dredging in the Kansas River

Abstract

In-stream dredging is a common practice in rivers worldwide that can affect fish and fish habitat. We investigated the magnitude of these alterations and their influence on the fish community of the Kansas River, a large sand bed river. Fishes were collected monthly from June 2010 to June 2011 in Edwardsville and Lawrence, KS from 12, 1-km reaches (three actively dredged, two historically dredged that have not been dredged in at least one month, and seven control reaches) with bottom trawls, seines, and electrofishing. Water depths and velocities were measured with an acoustic doppler current profiler and interpolated in ArcGIS at all 12 reaches.Actively dredged reaches had proportionally more deep water habitat (> 3 m) and lower velocity (< 0.15 m/s) near the river bed than control reaches (P < 0.01 and P = 0.04, respectively).However, the mean proportion of shallow water habitat (< 0.5 m), high velocities near the river bed (> 0.30 m/s), low velocity habitat (< 0.25 m/s), and high velocity habitat (> 0.75 m/s) were similar among all reach types (Ps > 0.05). A canonical correspondence analysis was used to characterize relationships among habitat variables, reach types (actively dredged, historically dredged, and control), and catch per unit effort (CPUE) of fishes in the Kansas River. Mean velocity and depth explained a significant amount of variation in species CPUE; however, reach type was not a significant factor for any of the gear types for any season. Our results show that dredging in Great Plains Rivers can increase depths, but alterations to fish community structure was not evident, likely because many of these fishes are adapted to a range of habitat conditions and are highly mobile.iii

Evaluating the influence of environmental variables on fish assemblages along Tropical Andes: considerations from ecology to conservation

“…One of the main consequences of constructing these small obstacles is the hydromorphological modification of stretches, affecting fish communities (Tobes et al, 2016a;Latli et al, 2019). Similarly, other habitat alterations as channelisation or dredging produce significant modifications on fish assemblages (Fischer et al, 2012;Reis, 2013;Chiu & Suen, 2016).…”

Channel morphology and flow structure of an abandoned channel under varying stages

“…Under such conditions, deposition occurs along the length of the abandoned channel rather than focused at the channel entrance [ Constantine et al ., , 2010b; Sutton et al ., ]. The bed material of the Kansas and Big Blue rivers, like other large rivers in the region [ Costigan et al ., ], is fine‐grained [ Fischer et al ., , ] and the bed of the abandoned channel likely aggraded quickly when it was transitioning from being the main course of the Kansas River [ Constantine et al ., ]. Sections in the middle of the abandoned channel were unable to be surveyed due to shallow depths, which are likely the location in the channel where bed load transported into the channel deposited.…”

“…Gallery forests form the riparian zone of the Kansas and Big Blue rivers [ Veach et al ., ]. The Kansas and Big Blue rivers are both large, fine sand‐bed rivers with meandering planforms [ Fischer et al ., , ]. The bed of the abandoned channel was at a higher vertical elevation than the bed of the Big Blue and Kansas rivers (e.g., the bed of the abandoned channel is perched).…”

Influence of Riparian and Watershed Alterations on Sandbars in a Great Plains River

“…sand dredging and channelization) because the resolution of the aerial photos was not fine enough to allow these factors to be accurately quantified. Reductions in sandbars and alterations to channel morphology have been documented where sediment load was reduced through dredging (Kondolf, 1997), which in the Kansas River, is a major source of sediment loss that may influence channel morphology (Fischer et al, 2012). Channelization structures also are intermittently present throughout the Kansas River, which constrict flow to a narrowed main channel (Pinter et al, 2010) and may reduce sediment availability and deposition through reducing lateral channel migration and artificially increasing bankfull stream power.…”