Lower White River Research Articles

Comparisons of oxbow lake fish assemblages in relation to bigheaded carp establishment in the lower White River, Arkansas

BackgroundSince the late 1990s, bigheaded carps (largely silver carp [Hypophthalmichthys molitrix] but also bighead carp [H. nobilis]) have established throughout the lower Mississippi River basin. Using previously studied oxbow lakes in the lower White River basin, Arkansas, we compared current (2017, “post-carp” establishment) fish assemblages to historical (2002, “pre-carp” establishment) fish assemblages. Fish assemblages were comprehensively assessed using multiple gears, including boat electrofishing, mini-fyke nets, and experimental small-mesh gill nets.ResultsT-tests suggested that fish assemblage indices of richness, diversity, evenness, and dominance were often greater (P < 0.05) during the post-carp period as reflected by boat electrofishing and experimental gill nets. However, all indices were generally similar (P > 0.05) between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets. Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods. Assemblage differences were linked to both small and large abundance changes for more than 20 species. Abundances of gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides), pugnose minnow (Opsopoeodus emiliae), crappies (Pomoxis spp.), bluegill (Lepomis macrochirus), orangespotted sunfish (L. humilis), and yellow bass (Morone mississippiensis) declined between the pre-carp and post-carp periods. Conversely, abundances of weed shiner (N. texanus), pallid shiner (Hybopsis amnis), longear sunfish (L. megalotis), buffalofishes (Ictiobus spp.), and gars (Lepisosteus spp.) generally increased during the same period.ConclusionsAlthough not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish, the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White River ecosystem during the past two decades. Thus, it is probable to conclude that post-carp establishment observations from this study were at least, in part, attributable to bigheaded carp establishment. Impacts of further range expansions by bigheaded carps in the White River and other lower Mississippi River sub-basins are unclear, though this study suggests probable effects on native fish assemblages, underscoring the need for further research and monitoring.

Fluvial responses to late Holocene hydroclimate variability in the midcontinental United States

Long-term relationships between mean-state climatic conditions and flood frequencies in the midcontinental United States (US) are not well established because instrumental records of fluvial processes are limited to the current warm period (CWP; the last ca. 150 years) and continuous paleo-flood records are exceedingly rare. Here, we investigate climate-flood relationships in the midcontinental US by reconstructing flood frequencies at Half Moon Pond, a 1600-year-old oxbow lake on the lower White River, Indiana (watershed = ca, 29,000 km2). We used sediment accumulation rates and clastic fluxes constrained by high-resolution radiocarbon (14C) dating. Frequent flooding, as indicated by high sedimentation rates and clastic fluxes to Half Moon Pond, occurred leading up to and during the Medieval Climate Anomaly (MCA; 950–1250 CE) when paleoclimate records suggest the predominance of ocean-atmosphere mean states resembling the negative phases of the Pacific Decadal Oscillation (-PDO-like) and Pacific North American Mode (-PNA-like). Reductions in sedimentation rates and clastic fluxes, indicating reduced flooding, subsequently occurred during the transition out of the MCA and into the Little Ice Age (LIA; 1250–1830 CE) as ocean-atmosphere conditions shifted to + PDO-like and +PNA-like mean states. Sedimentation rates and clastic fluxes increased again after ca. 1800 CE, indicating increased flooding during the CWP as ocean-atmosphere conditions returned to -PDO-like and -PNA-like mean states. The White River trends were notably antiphased with sedimentation-rate-based flood frequencies for the lower Ohio River (500,000 km2 watershed) prior to 1830 CE. This antiphased relationship is consistent with flooding in moderate to small watersheds in the Midwest being sensitive to the occurrence of rainstorm events, which were more frequent leading up to and during the MCA, and flooding in large watersheds being more sensitive to large spring melts associated with extensive snowpacks, which characterized the LIA. That both the White and Ohio rivers experienced their most frequent flooding during the CWP suggests deforestation and changing land use practices increased flooding on Midwestern watersheds across scales despite a current climatic mean state that in the past only resulted in increased flooding on moderate to small watersheds. Continued increased in midcontinental rainfall are therefore likely to enhance the occurrence of floods in Midwestern watersheds across different geographic scales.

Coarse sediment dynamics in a large glaciated river system: Holocene history and storage dynamics dictate contemporary climate sensitivity

Abstract The gravel-bedded White River drains a 1279 km2 basin in Washington State, with lowlands sculpted by continental glaciation and headwaters on an actively glaciated stratovolcano. Chronic aggradation along an alluvial fan near the river’s mouth has progressively reduced flood conveyance. In order to better understand how forecasted climate change may influence coarse sediment delivery and aggradation rates in this lowland depositional setting, we assessed the contemporary delivery and routing of coarse sediment through the watershed; this assessment was based on a rich set of topographic, sedimentologic, and hydrologic data from the past century, with a focus on repeat high-resolution topographic surveys from the past decade. We found that most of the lower river’s contemporary bed-load flux originates from persistent erosion of alluvial deposits in the lower watershed. This erosion is a response to a drop in local base level caused by a major avulsion across the fan in 1906 and then augmented by subsequent dredging. The 1906 avulsion and modern disequilibrium valley profiles reflect landscape conditioning by continental glaciation and a massive mid-Holocene lahar. In the proglacial headwaters, infrequent large sediment pulses have accomplished most of the observed coarse sediment export, with exported material blanketing downstream valley floors; during typical floods, transported bed material is largely sourced from erosion of these valley floor floods. Throughout the watershed, we observe decadal-scale coarse sediment dynamics strongly related to the filling or emptying of valley-scale sediment storage over 102–104 yr time scales, often in response to major disturbances that either emplace large deposits or influence their redistribution. Paraglacial responses in large watersheds are suggested to be inherently complicated and punctuated as a result of internal landform interactions and stochastic/threshold-dependent events. We argue that, in combination, Holocene disturbance, storage dynamics, and human flow modification make coarse sediment fluxes in the lower White River relatively insensitive to decadal climate variability. Results highlight the degree to which river sensitivity to contemporary disturbance, climatic or otherwise, may be contingent on local and idiosyncratic watershed histories, underscoring the need to unpack those histories while demonstrating the utility of watershed-scale high-resolution topography toward that end.

Freshwater Mussel Bed Habitat in an Alluvial Sand-Bed-Material-Dominated Large River: A Core Flow Sediment Refugium?

Habitat degradation, organismal needs, and other effects influencing freshwater mussel declines have been subject to intense focus by conservationists for the last thirty plus years. While researchers have studied the physical habitat requirements and needs of mussels in small- to medium-sized rivers with variable levels of success, less research has been conducted on mussel habitat in larger non-wadeable rivers, especially at the reach scale, where core flow environmental conditions provide and maintain habitat for freshwater mussels. We designed a quasi-experimental observational field study to examine seven hydrologic energy and material variables laterally and longitudinally at Current and Extirpated mussel bed habitat reaches in lower White River, Arkansas, a large non-wadeable, sand-bed-material-dominated river. As expected, lateral and longitudinal hydrologic variable differences were identified within a reach. Mean velocity, bed velocity, the Froude number, and stream power were all significantly lower at Current mussel bed habitat stations within a sampling reach. Energy regime differences in shear stress and, marginally, stream power were higher at Extirpated mussel bed habitat reaches. Several factors emerged as important to mussel habitat in the White River. First, bed velocity warrants further exploration in terms of both flow strength and flow direction. Second, bedload appears to be the primary contributor to mussel habitat but requires additional exploration within the context of core and secondary flow pathway interactions. The combined empirical evidence from our study supports the flow refugium concept identified for mussel habitats in smaller systems but expands the concept to large non-wadeable streams and includes reach-scale refuge from sediment transport conditions.

Geomorphic adjustment to hydrologic modifications along a meandering river: Implications for surface flooding on a floodplain

Responses of large regulated rivers to contemporary changes in base level are not well understood. We used field measurements and historical analysis of air photos and topographic maps to identify geomorphic trends of the lower White River, Arkansas, USA, in the 70years following base-level lowering at its confluence with the Mississippi River and concurrent with flood control by dams. Incision was identified below a knickpoint area upstream of St. Charles, AR, and increases over the lowermost ~90km of the study site to ~2m near the confluence with the Mississippi River. Mean bankfull width increased by 30m (21%) from 1930 to 2010. Bank widening appears to be the result of flow regulation above the incision knickpoint and concomitant with incision below the knickpoint. Hydraulic modeling indicated that geomorphic adjustments likely reduced flooding by 58% during frequent floods in the incised, lowermost floodplain affected by backwater flooding from the Mississippi River and by 22% above the knickpoint area. Dominance of backwater flooding in the incised reach indicates that incision is more important than flood control on the lower White River in altering flooding and also suggests that the Mississippi River may be the dominant control in shaping the lower floodplain. Overall, results highlight the complex geomorphic adjustment in large river-floodplain systems in response to anthropogenic modifications and their implications, including reduced river-floodplain connectivity.

Wetland tree transpiration modified by river‐floodplain connectivity

AbstractHydrologic connectivity provisions water and nutrient subsidies to floodplain wetlands and may be particularly important in floodplains with seasonal water deficits through its effects on soil moisture. In this study, we measured sapflow in 26 trees of two dominant floodplain forest species (Celtis laevigata and Quercus lyrata) at two hydrologically distinct sites in the lower White River floodplain in Arkansas, USA. Our objective was to investigate how connectivity‐driven water table variations affected water use, an indicator of tree function. Meteorological variables (photosynthetically active radiation and vapor pressure deficit) were the dominant controls over water use at both sites; however, water table variations explained some site differences. At the wetter site, highest sapflow rates were during a late‐season overbank flooding event, and no flood stress was apparent. At the drier site, sapflow decreased as the water table receded. The late‐season flood pulse that resulted in flooding at the wetter site did not affect the water table at the drier site; accordingly, higher water use was not observed at the drier site. The species generally associated with wetter conditions (Q. lyrata) was more positively responsive to the flood pulse. Flood water subsidy lengthened the effective growing season, demonstrating ecological implications of hydrologic connectivity for alleviating water deficits that otherwise reduce function in this humid floodplain wetland.

Population demographics of American eelsAnguilla rostratain two Arkansas, U.S.A., catchments that drain into the Gulf of Mexico

The goal of this study was to compare American eel Anguilla rostrata life history in two inland river systems in Arkansas, U.S.A., that ultimately discharge into the Gulf of Mexico via the Mississippi River and the Red-Atchafalaya catchments. From 21 June 2011 to 24 April 2014, 238 yellow-phase A. rostrata were captured in the middle Ouachita River and tributaries using boat electrofishing and 39 in the lower White River using multiple sampling gears. Most of them were caught downstream of dams in both basins (61%). Medium-sized A. rostrata ranging from 225 to 350 mm total length (LT ) were the most abundant size group in the Ouachita River basin, but they were absent from the White River. Mean LT at age 4 years (i.e. youngest shared age) was 150 mm greater for the White River than the Ouachita River basin. Anguilla rostrata appeared to have a greater initial LT (i.e. minimum size upon arrival) in the White River that allowed them to reach a gonado-somatic index (IG ) of 1·5 up to 4 years earlier, and downstream migration appeared to occur 5 years earlier at 100 mm greater LT ; these differences may be related to increased river fragmentation by dams in the Ouachita River basin. Growth and maturation of A. rostrata in this study were more similar to southern populations along the Atlantic coast than other inland populations. Adult swimbladder nematodes Anguillicoloides crassus were not present in any of the 214 swimbladders inspected. Gulf of Mexico catchments may be valuable production areas for A. rostrata and data from these systems should be considered as range-wide protection and management plans are being developed.

Tributary Spawning by Endangered Colorado River Basin Fishes in the White River

AbstractThe Green River system in the upper Colorado River basin supports populations of endangered Razorback Sucker Xyrauchen texanus and Colorado Pikeminnow Ptychocheilus lucius. Documented spawning areas for these species are few and occur mainly in the Green River main stem and the lower reach of the tributary Yampa River. Herein, we report spawning by both species in an additional Green River tributary, the White River. We documented Razorback Sucker and Colorado Pikeminnow larvae and early juveniles in a 20‐km reach of the lower White River, Utah, in 2011. Movement of hatchery‐produced Razorback Sucker adults into the White River and subsequent reproduction suggests that these fish use the system to complete important life history processes. Presence of spawning areas for two endangered fishes in the White River emphasizes the important role of tributaries for providing spawning and rearing habitat for native and endangered fishes.Received April 2, 2013; accepted July 18, 2013

A geospatial tool for delineating streambanks

Ecologists, civil engineers, and conservation managers currently lack an automated software tool for delineating streambanks, which is an important input for various hydrological studies. Therefore, a computational method for automatically delineating streambanks using aerial imagery and stream centerline datasets was developed and incorporated in a stand-alone, user-friendly desktop-based geospatial tool. This interactive tool, titled Streambank Delineator (StreBanD), was tested on the 161-km Lower White River and 158-km L'Anguille River in Eastern Arkansas using 1-m resolution 3-band aerial imagery and National Hydrography Dataset Plus (NHDPlus) stream centerline. The near-infrared band and normalized difference water index (NDWI) were evaluated for feasibility of streambank delineation. Results showed that the NDWI, a multi-band index approach, consistently provided superior delineations when compared to the single band (near-infrared) approach especially for complex channel morphologies, including braided channels and meandering segments, in the L'Anguille River. The geospatial tool successfully delineated the streambanks for both rivers in less than 10 min with a mean error ranging from 0.3 m to 10.3 m when compared with five manually delineated streambanks. Due to the generic and simple nature of this tool, it should assist scientists and conservationists in rapidly delineating streambanks for their study areas.

A Survey of Bowfishing Tournaments in Arkansas

AbstractBowfishing is an understudied method of fishing that appears to be legal throughout the United States. Therefore, species composition and harvest rates were determined at six bowfishing tournaments held in Arkansas at the lower White River, the Arkansas River at Lake Dardanelle, the Arkansas River at Piney Bay, Lake DeGray, Bull Shoals Lake, and Lake Ouachita between July 1999 and May 2000. A total of 3,280 fish were harvested at the six tournaments; of this total, 2,751 fish representing 19 species were identified. Total harvest per tournament ranged from 179 to 1,674 fish and from 6 to 12 species. Mean (±SD) harvest rate for tournament participants was 3.8 ± 1.1 fish/h; among tournament winners, the harvest rate was 7.7 ± 2.8 fish/h, which appears high compared with other sport fisheries (range = 0.28–2.59 fish/h). Five species accounted for 84% of fish harvested: spotted gar Lepisosteus oculatus, common carp Cyprinus carpio, shortnose gar L. platostomus, spotted sucker Minytrema melanops, and smallmouth buffalo Ictiobus bubalus. Rank number of each species harvested at the tournaments was correlated (P &lt; 0.05) for only 4 of 15 pairwise comparisons, which suggests that harvest often varies by tournament. Tournaments held at the Arkansas and White rivers had correlated harvest, as did spring tournaments held at the Ouachita River drainage reservoirs (i.e., Lake DeGray and Lake Ouachita). Harvest of fish smaller than published size‐at‐maturity estimates was generally not problematic but appeared to be of greatest concern for smaller‐bodied catostomid species. This study indicates that tournament bowfishers have higher harvest rates than traditional rod‐and‐reel anglers. Results of this survey should provide baseline information that may assist natural resource agencies with management of bowfishing.

Comparison of Gears for Sampling Littoral‐Zone Fishes in Floodplain Lakes of the Lower White River, Arkansas

AbstractGear comparison studies are useful to fisheries managers because many aquatic systems require multiple gears to assess fish assemblages. Many previous studies have emphasized comparisons of catch per unit effort or basic community measures such as richness and diversity. Our objectives were to (1) compare fish assemblage richness, diversity, and evenness across sampling gears, (2) assess the similarity of fish assemblage structure as depicted by the different gears, and (3) compare fish assemblage–environment relationships depicted by the different gears. Assessments were conducted in littoral‐zone areas of 16 floodplain lakes in the lower White River, Arkansas. Four sampling gears were used: 500‐V, 60‐Hz (high‐pulse) and 1,000‐V, 15‐Hz (low‐pulse) boat‐mounted nighttime electrofishing, mini‐fyke nets, and experimental gill nets. Species richness and diversity were significantly greater using boat‐mounted electrofishing (both pulses) than the other gears. Experimental gill nets exhibited the lowest richness of all gears (&lt;50% of the other gears), and mini‐fyke nets exhibited significantly lower evenness owing to the tendency for 1–2 species to dominate catches. Procrustean analyses indicated that the lake‐specific fish assemblages depicted by the different gears were significantly different during all paired‐gear comparisons except between the two electrofishing configurations. Regardless of gear, multivariate direct gradient analyses indicated that lake depth, water clarity, and morphoedaphic index were consistently important variables associated with the structuring of littoral‐zone fish assemblages. The results support the idea that multiple‐gear approaches are useful in assessing floodplain lake fish assemblages and that, in the case of lower White River floodplain lakes, the assemblage information collected from the different gears was not redundant. Additionally, if a large‐river sampling program is using only one or two gears, major fish–environment relationships that are depicted may not be gear dependent.

Adult and juvenile paddlefish in floodplain lakes along the lower White River, Arkansas

Eleven floodplain lakes in the lower White River, Arkansas were sampled using a boat electrofisher and gill nets during periods of river connection (April–May 2004) and disconnection (June–July 2004 and 2005). Environmental characteristics, including water quality and lake morphometrics were concurrently measured in each lake. Average measures of connectivity were calculated for the preceding 5-year period. Of the 11 lakes sampled, 7 lakes contained paddlefish. A total of 44 paddlefish were observed during the study, but only 1 was observed during the period of river connection. Eye-fork lengths ranged from 348– 1040 mm (n = 38). Paddlefish ranged in age from 3–19 years (n = 27). Paddlefish were more likely to be found in long narrow floodplain lakes that connected to the river early in the year. Paddlefish catch per unit effort increased as lake surface area, dissolved oxygen level, and variability in the start date of connection increased. Our research indicated that both juvenile and adult paddlefish use White River floodplain lakes, despite the risk of being isolated in lakes for long periods or being prevented from accessing riverine spawning habitat.

Historical Geography of the Lower White River

Historical Geography of the Lower White River