Sandy-bottomed Streams Research Articles

Beaver-related restoration: An opportunity for sandy lowland streams in a human-dominated landscape

The expansion of beavers into human-dominated landscapes can help improve the ecological status of degraded streams. This study aimed to assess the changes in the ecological status of a degraded sandy-bottom stream under the influence of processes generated by the activity of a European beaver. We assumed that the processes in the beaver dam-and-pond complex significantly improved the physical, chemical, and bacteriological properties of water and improved the ecological status of a small lowland stream in a human-dominated landscape. To achieve these objectives, water for quality assessment, benthic invertebrates, and fish samples were collected, and the forms of land use and the natural values of the stream were analysed. In the upstream zone of the sandy-bottom stream flowing in a human-dominated landscape, the inflow of pollutants caused a significant reduction in water quality. The amount of nutrients was high and the amount of dissolved oxygen was low. Similarly, the number of meso- and psychrophilic bacteria was significantly higher than in the reference stream. The building activity of beavers initiated a series of positive environmental changes, and beaver ponds improved the self-purification of water in a polluted stream. In the lower part of the studied stream, after the stream passed through the beaver wetland system, the water quality improved, which was indicated by a significant improvement in physicochemical, microbiological, and biotic indicators, that is based on macrozoobenthos and fish. By constructing dams, beavers flooded large areas and created habitats for plant and animal species associated with wetlands, including amphibians, birds, and mammals. The improvement of the ecological status of the stream, combined with the preservation and restoration of wetland habitats in the catchment area, enables the use of ecosystem services provided by the streams in the human-dominated landscape and their surroundings.

Sediment and biota trace element distribution in streams disturbed by upland industrial activity.

Extensive industrial areas in headwater stream watersheds can severely impact the physical condition of streams and introduce contaminants. We compared 3 streams that received stormwater runoff and industrial effluents from industrial complexes to 2 reference streams. Reference streams provide a benchmark of comparison of geomorphic form and stability in coastal plain, sandy-bottomed streams as well as concentrations of trace elements in sediment and biota in the absence of industrial disturbance. We used crayfish (Cambarus latimanus, Procambarus raneyi, Procambarus acutus) and crane fly larvae (Tipula) as biomonitors of 15 trace elements entering aquatic food webs. Streams with industrial areas were more scoured, deeply incised, and less stable. Sediment organic matter content broadly correlated to trace element accumulation, but fine sediments and organic matter were scoured from the bottoms of disturbed streams. Trace element concentrations were higher in depositional zones than runs within all streams. Despite contaminant sources in the headwaters, trace element concentrations were generally not elevated in sediments of the eroded streams. However, element concentrations were frequently elevated in biota from these streams with taxonomic differences in accumulation amplified. In eroded, sand-bottomed coastal plain streams with unstable sediments, single snapshots of sediment trace element concentrations did not characterize well bioavailable trace elements. Biota that integrated exposures over time and space within their home ranges better detected bioavailable contaminants than sediment. Environ Toxicol Chem 2019;38:115-131. © 2018 SETAC.

<strong>A simple, inexpensive artificial stream for rearing Ephemeroptera from sandy substrates</strong>

We describe a simple, inexpensive artificial stream to rear mayflies from sandy bottom streams. It consisted of a 151 L tub containing sand and water from a local stream. A small submersible pump circulated the water and netting was placed over the tub to collect adults. The stream was operated in a heated greenhouse. This artificial stream was remarkably productive. We collected over 2100 adult mayflies representing 6 genera along with several Trichoptera and Diptera adults. This stream was productive for 55 weeks with minimal maintenance.

A Tube Seepage Meter for In Situ Measurement of Seepage Rate and Groundwater Sampling.

We designed and evaluated a "tube seepage meter" for point measurements of vertical seepage rates (q), collecting groundwater samples, and estimating vertical hydraulic conductivity (K) in streambeds. Laboratory testing in artificial streambeds show that seepage rates from the tube seepage meter agreed well with expected values. Results of field testing of the tube seepage meter in a sandy-bottom stream with a mean seepage rate of about 0.5 m/day agreed well with Darcian estimates (vertical hydraulic conductivity times head gradient) when averaged over multiple measurements. The uncertainties in q and K were evaluated with a Monte Carlo method and are typically 20% and 60%, respectively, for field data, and depend on the magnitude of the hydraulic gradient and the uncertainty in head measurements. The primary advantages of the tube seepage meter are its small footprint, concurrent and colocated assessments of q and K, and that it can also be configured as a self-purging groundwater-sampling device.

Current velocity as a factor in determining macroinvertebrate assemblages on wood surfaces

The velocity of moving water near submerged wood surfaces may be an important factor for shaping benthic communities in sandy-bottomed streams. As wood can be suspended above the streambed and be kept free of inundating sediments, wood substrates may provide the primary hard surface for macroinvertebrate colonization. To examine this, we sampled macroinvertebrate assemblages from the surface of 20 pieces of submerged wood in a sandy-bottomed stream in the west-central Wisconsin. Near-surface velocity was characterized at the wood surface and the streambed macroinvertebrate assemblage was sampled near each wood piece for comparison. We found that the density of macroinvertebrates was five times greater on wood than the sandy streambed and the average richness on wood was twice as great. Macroinvertebrate abundance and richness on wood surfaces increased with velocity; however, abundance increased as a consequence of adding taxa rather than adding individuals of the dominant taxa. These data suggest that near-surface current velocity on wood may be an important determinant of benthic community composition when the availability of other hard surfaces is limited.

Fine particulate organic matter transport dynamics in a small Coastal Plain stream: influence of hydrology and channel morphology

Fine particulate organic matter (FPOM) represents a major component of stream organic matter budgets, and its dynamics greatly affect the productivity and metabolism of a stream community. FPOM transport dynamics has been well documented in high-gradient streams with rocky substrates, but information from low-gradient, sandy-bottom streams has been lacking. We estimated FPOM retention patterns in Payne Creek, a 2nd order Coastal Plain stream (USA), under naturally varying hydraulic conditions (discharge and velocity). Corn pollen, as an FPOM analogue, was released along with a conservative solute tracer and the particle retention coefficient (k p) was calculated by fitting the ratio of total pollen remaining in the water column against the longitudinal transport distance to an exponential decay model. Pollen k p (n = 4) ranged from 0.034 to 0.214 /m, and particle transport distance (S p) ranged from 4.7 to 29.7 m. The S p measured in Payne Creek was in the lowest range of previously reported values, and such rapid particle retention was attributed to the low channel slope and slow current velocity. S p was significantly correlated to water velocity and the channel friction factor, but not to discharge (Q). Two summer experiments conducted in contiguous stream segments resulted in the shortest (4.7 m) and longest (29.7 m) S p, despite the similar Q. This was attributed to the segment-scale channel alterations that occurred during the previous winter, which led to very different hydraulic conditions in the two stream segments. In Payne Creek, seasonal changes in hydrology and segment-scale variation in channel morphology were the main factors controlling FPOM transport and retention.

Contrasting Effects of Sand Burial and Exposure on Invertebrate Colonization of Leaves

Leaf detritus in streams fills dual resource roles as habitat and as food. Unless retained by some structural component, detritus gets transported to downstream reaches out of the local system. Low gradient sandy-bottomed streams retain leaf detritus via burial in sand, but this mechanism of retention limits the availability of detritus as a resource for the benthic community. We hypothesized that burial of leaf litter in sand would impact invertebrate colonization by reducing density and richness on leaf litter. We conducted a short-term experiment (i.e., 2 wk) in a sandy-bottom stream in which leaves were subject to either burial in sandy substrate, exposure to the water column, or a sequential combination of both. Results showed that 2 wk burial of leaf litter significantly impacted the colonization of benthic invertebrates. Burial or exposure status of leaves at the time of collection represented the major factor influencing invertebrate abundances on leaf litter. Leaves exposed to the water column had the highest abundance of invertebrates, dominated by collector-gatherers, that suggests the primary role of leaf litter as refugia in this system. Burial of leaf litter in sand had a significantly negative effect on invertebrate colonization of leaf litter. Furthermore, no difference existed in invertebrate colonization on leaf litter that had never been buried versus leaf litter that had been buried for 1 wk and then exposed and collected after a week in the water column. This suggests short-term burial of leaf litter does not influence colonization by invertebrates once leaf litter is exposed to the water column. The results of this study suggest that the benthic colonization on newly exposed leaf litter is rapid, potentially due to a lack of habitat structure availability in the sandy-bottomed stream.

Plastic and unpredictable responses of stream invertebrates to leaf pack patches across sandy-bottomed streams

Detrital inputs to ecosystems provide potential food sources and can produce trophic cascades, but this effect is influenced by whether species specialise in consuming or inhabiting accumulations of detritus. To test whether species are differentially associated with leaves or sand, we compared densities of stream invertebrate species in patches of leaves and bare sand in two sandy-bed creeks in south-eastern Australia, in summer and spring. We also assessed the quality of information on diet and substrate association in the literature. Most species showed no density differences between leaf and sand patches (‘microhabitat generalists’), but categorisation as generalists, leaf or sand species differed between datasets. We developed a method for identifying important effect sizes; power analyses showed that many species were true generalists, but many non-significant results were potentially Type II errors. The literature provided information that was broadly consistent with our data, but few studies publish reliable information about either diet or patch use. Our results support a contention that few Australian stream invertebrates are obligate shredders, and this may also be true for streams elsewhere. Predicting and detecting the responses of such generalist taxa to detrital inputs will be very challenging.

Taxonomy of Simulium guaporense Py-Daniel (Diptera: Simuliidae) from Brazil, with the first description of males and females

We describe Simulium guaporense Py-Daniel adults and redescribe some morphological characters of its larvae and pupae based on specimens collected near the type locality in Rondônia State, Brazil. We report this species for the first time in Mato Grosso State. This species was placed originally in the S. siolii species group of the subgenus Psaroniocompsa; however, the thoracic pattern of the adults of S. guaporense is similar to that of species in the S. auristriatum species group. The immature stages were found on deciduous leaves and trailing vegetation in sandy-bottomed streams. Females were collected biting humans.

New Records of Chironomidae (Insecta: Diptera) from Mongolia with Review of Distribution and Biogeography of Mongolian Chironomidae

Fourteen species of Chironomidae (Diptera) are recorded for the first time from the Hovsgol Nuur region, Mongolia, increasing the total number of chironomid species from this country to 166 (Table 1). Two major studies have contributed the most data on distribution of Chironomidae in Mongolia. The first study, summarized by Kozhova et al. (1994) and Erbaeva and Safronov (in press), was based on 20 years of research on Hovsgol Nuur, an ancient lake in Northern Mongolia. The second study, by Sasa and Suzuki (1997), described many new species and listed many species of Chironomidae from Central and Southwestern Mongolia. In addition, Reiss (1971) described and listed species of Chironomidae collected from sites throughout the country and Hayford and Ferrington (in press) studied the distribution of chironomids in Hovsgol Nuur. The current valid name-author-date and biogeographic region distribution for Mongolian Chironomidae were obtained from Ashe and Cranston (1990) and are listed with the Mongolian distribution for each species in Table 1. Of the 118 species of Chironomidae listed from the Hovsgol Nuur Region, fourteen are new records for Mongolia (Table 1). Collections were made during June and July of 1995-1997 as part of a joint United States, Mongolian, and Russian expedition to the Hovsgol Nuur Region. Adults were collected using malaise traps and sweep nets and pupal exuviae were collected using methods modified from Ferrington (1987). Eight of the fourteen newly recorded species, Ablabesmyia nr. cinctipes (Johannsen), Cricotopus (Cricotopus) cylindraceus (Kieffer), Heterotrissocla dius subpilosus (Kieffer), Parakiefferiella nr. smolandica (Brundin), Psectrocladius (Psectrocladius) schlienzi Wiilker, Psectrocladius (Psectrocladius) sordidellus (Zetterstedt), Dicrotendipes lobiger (Kieffer), and Dicrotendipes septimacullipennis (Goetghebuer) were collected from the shore of Modon Hui, an island in Hovsgol Nuur. Six species, Krenosmittia camptophleps (Edwards), Parametriocnemus boreoalpinus Gouin, Rheosmittia spinicornis (Brundin), Saetheria reissi Jackson, Cladotanytarsus vanderwalei (Edwards), and Corynocera ambigua (Zetterstedt) were collected from sandy bottom streams flowing into Hovsgol Nuur. Most of the Chironomidae in Mongolia have a cosmopolitan distribution (Table 1). Forty-seven species have a Holarctic distribution, with some additionally found in the Oriental and Neotropical regions. Seventy-nine species have a Palaearctic distribution, with some of these additionally found in the Oriental, Afrotropical and Australasian regions. Species with a Palaearctic distribution tended to have a West Palaearctic distribution, with very few species having an East Palaearctic distribution. This distribution is similar to that of caddisflies reported by Morse et al. (in press), with the exception that most caddisflies were also found in the nearby East Palaearctic region. Nearly 20% of the species of Chironomidae found in Mongolia are endemic, with most described by Sasa and Suzuki (1997). However, note that specific type localities are not clear. Thus, it is uncertain where some species were originally collected. Distribution records for species within Mongolia come primarily from the Hovsgol Nuur region or from sites close to Ulaanbaatar. Currently, two studies are underway to collect Chironomidae in central (Selenge River basin) and western (saline lake district) Mongolia, which should vastly increase the known species of Chironomidae from this country.

Stream regulation and nitrogen dynamics in sediment interstices: comparison of natural and straightened sectors of a third‐order stream

AbstractNitrogen dynamics were studied in the interstitial environment (i.e. hyporheic zone) of a sandy‐bottom stream in a rural landscape. A third‐order stream in Brittany (France) was studied at 11 stations (riffles) to evaluate spatial patterns of water exchange between surface and interstitial habitats. More intensive sampling was conducted in three riffles selected according to their hydrological characteristics. Chemical characteristics (especially nitrogen) and microbial denitrification were studied at 12.5 and 25 cm depth upstream, and 25 cm depth downstream of each riffle. This study confirms that the interstitial habitat of a N‐rich stream acts as a sink for the nitrate‐nitrogen. Experimental manipulation of sediment cores indicates that denitrification is limited by carbon in surface (i.e. benthic) and by nitrate in hyporheic sediments. River regulation increases inputs of fine sediments, modifies river channel location, and generates changes in the spatial patterns of biogeochemical processes, water origins, and hydrologic exchanges. Copyright © 2004 John Wiley & Sons, Ltd.

Larval habitat associations ofProgomphus obscurusat two spatial scales (Odonata: Gomphidae)

Progomphus obscurus is one of the most abundant dragonflies in South Carolina, USA. We collected dragonfly larvae from 127 sites in the Enoree River and nine of its tributaries, and correlated the abundance of P. obscurus larvae with physical and chemical characteristics of these streams. As expected for this burrowing species, larval abundance varied among streams and was significantly correlated with mean silica concentrations and the proportion of sandy-bottom sites in these streams. We also examined habitat associations on a smaller spatial scale. We sampled P. obscurus larvae by kick-seine from fine sand, coarse sand, and pebble sediment types in five sites in the Enoree River basin. Larvae were collected, preserved in 75% EtOH, and their body lengths were measured. Sediment samples were collected and Ro-tapped, and mean particle size was calculated. Larvae were present in a greater fraction of the ‘fine sand’ samples than ‘pebble’ samples . In addition, abundance was inversely correlated with mean particle size. Mean larvae size was weakly correlated with mean particle size , and inversely correlated with larval abundance . This species is associated with sandy-bottom streams and fine sandy sediments within streams. Changes in sediment characteristics resulting from channelization, increased flooding, and increased stream flow could change sediment composition and impact the abundance of this common dragonfly

Patch- and reach-scale dynamics of a macrophyte-invertebrate system in a New Zealand lowland stream

Abundant growths of macrophytes are a common feature of streams in open lowland areas of New Zealand during summer, but the values of these to aquatic biota are poorly understood. We studied the temporal dynamics of, and associations amongst, elements of a macrophyte-invertebrate system to provide an improved information base for lowland stream management. The biomass of macrophytes increased significantly over the four quarterly sampling occasions from 43.8 g m-2 in June to 370.8 g m-2 in March; biomass was dominated by Egeria densa on all dates, except in December when Potamogeton crispus was dominant. We did not detect strong associations between epiphyton biomass and invertebrate abundance in our study, but this may reflect the fact that we sampled loosely-adhering epiphyton on young, surface-reaching shoots whereas invertebrates were collected from macrophytes growing through the water column. Density of some invertebrate species per gram dry weight of plant material varied by macrophyte type, with the chironomids Tanytarsus vespertinus and Naonella forsythi displaying positive correlations with Egeria and Potamogeton biomass, respectively. The shrimp Paratya curvirostris accounted for 50% of phytophilous invertebrate biomass, with Chironomidae the only other group to comprise more than 9%. Abundance of total phytophilous invertebrates displayed a positive linear relationship with macrophyte biomass in a sample (0.1 m2), and a humped relationship with species richness, such that highest numbers of taxa occurred at macrophyte biomass levels around 400 g dw m-2. Our study suggests that intermediate macrophyte biomass levels are likely to enhance macroinvertebrate biodiversity in sandy-bottomed lowland streams.

Influence of log additions on physical and biotic characteristics of a mountain stream

Three pairs of cobble riffle study sites were established in a second-order stream in North Carolina and logs added to the downstream riffle at each site. At log addition transects, stream depth increased, current velocity decreased, cobble substratum was covered by sand and silt, and both coarse and fine particulate organic matter increased dramatically. Log additions had less dramatic effects on uptake lengths of ammonium, nitrate, and phosphate, but they had immediate and significant impacts on invertebrate community structure: abundances and biomass of scrapers and filterers decreased; collectors and predators increased; overall shredder biomass did not change, but biomass of trichopteran and dipteran shredders increased, while that of most plecopteran shredders decreased; and plecopteran predators also decreased despite greater abundances of potential prey. These observations suggest that physiological and morpho-behavioral constraints preclude many animals from tracking resources among patches when patches display very different abiotic conditions. Secondary production of scrapers and filterers decreased, whereas that of collectors and predators increased. The shifts in functional group abundances, biomass, and production between reference and debris-dam transects, which differed considerably from those previously reported for low-gradient, sandy-bottom streams, accentuate the importance of localized abiotic factors in structuring invertebrate communities within patches.

Response of invertebrates to lotic disturbance: a test of the hyporheic refuge hypothesis.

Recovery following hydrological disturbances is usually rapid for lotic invertebrates. Stream ecologists have assumed that recovery is facilitated by behavioral migrations during floods down into the hyporheic zone (the interstitial spaces of a streambed) to seek temporary refuge from possible erosion (the "hyporheic refuge hypothesis"). We provide the first explicit test of this hypothesis by evaluating three predictions of the hypothesis. We coupled field observations of the response of meiofaunal invertebrates to floods with field and flume experiments. The study site was a sandy-bottom stream in northern Virginia. Prediction 1, that loss of fauna from a streambed during floods should be minimal as long as the depth of scour in the streambed is less than the depth of the hyporheic zone, was not supported for any taxon. For two floods which varied considerably in magnitude, 50-90% of the fauna was lost from the bed despite the fact that the depth of scour (10-30 cm) was significantly less than the total depth of the hyporheic zone (50 cm). Prediction 2, that fauna should move deeper into the bed at higher flows, was supported by field observations during only one of two floods and then only for rotifers. In flume experiments that tested for finer scale behavioral movements, significant vertical migrations were found for copepods and chironomids which moved 1.5-3.5 cm downward as mean velocity (3 cm off bottom) was increased from 5-23 cm/s. Movements down by rotifers were not found in the flume experiments. Prediction 3, that the hyporheic zone is the most important source of colonists to defaunated areas, was supported in part by field experiments. The hyporheic route was not the primary route for any taxon but it was as important for the rotifers and copepods as water column or streambed surface routes. We conclude that, even though smallscale (cm's) migrations into the streambed in response to increased flow may be observed for some taxa and the hyporheic zone may serve as a partial source of colonists following disturbances, movements down are not adequate in preventing significant losses of meiofauna during floods.

Quantification of Wood Habitat in Subtropical Coastal Plain Streams

To assess the importance of woody debris in two relatively unaltered Coastal Plain streams in the southeastern United States, a line intersect technique, developed by foresters, was used to estimate volume, mass, surface area, and spatial distribution. The ash-free dry mass of in-channei woody material was 6.5 kg/m2 of stream channel bottom in the sixth-order Ogeechee River and 5.0 kg/m2 in the fourth-order Black Creek. Most wood is located near the erosional bank in these meandering streams. These wood mass estimates are much higher than expected for middle-order streams and are similar to those from several small headwater streams in other regions. Due to their very low slopes (<0.02%), these streams appear to have insufficient stream power to move large woody material. Snag, or woody, habitat is the major stable substrate in these sandy-bottomed streams and is a site of high invertebrate diversity and productivity. In-channel snag surface area per square metre of channel bottom was 0.249–0.433 m2 in the Ogeechee and 0.191–0.379 m2 in Black Creek, depending on the hydrograph stage. With invertebrate biomass of 6.6 g dry mass/m2 of snag surface, this results in an invertebrate biomass of at least 1.88 g/m2 of channel bottom. Wood is also important to fishes, providing a rich source of invertebrate food, habitat, and cover. In addition to its obvious biological role, wood enhances the ability of a stream to process and conserve nutrient and energy inputs and has a major influence on the hydrodynamic behavior of the river. The quantification of wood habitat seems mandatory to assess past or potential impacts of snag removal on ecosystem processes in low-gradient streams.

Food Habits of the Silverjaw Minnow, Ericymba buccata Cope, in an Intermittent Stream in Kentucky

The feeding activity of the silverjaw minnow, Ericymba buccata Cope, is closely associated with that of the bluntnose minnow, Pimephales notatus (Rafinesque), and the stoneroller minnow, Campostoma anomalum (Rafinesque). Digestive tracts of 249 silverjaw minnows, taken from two stations on Plum Creek, Spencer and Bullitt counties, Kentucky, were examined and the contents identified. These data were analyzed according to the size of the fish, time of the year, and the availability of food. The food category occurring most often in digestive tracts of fish of all sizes was the order Diptera, chiefly chironomids, followed by detritus, Ephemeroptera, and Cladocera. Minnows 33 to 45 mm total length consumed more cladocerans and fewer mayflies while the reverse was observed in specimens 46 to 76 mm. A greater variety of organisms was eaten by all fish in the winter and spring. INTRODUCTION A complete understanding of community dynamics in the aquatic ecosystem depends upon a thorough knowledge of each species present. The family Cyprinidae contains more members than any freshwater group, most of which are considered to be forage species. An understanding of the biology of certain members of this family is of great value in fisheries management. The silverjaw minnow is a highly successful forage species occurring commonly in the eastern and southeastern United States (Forbes and Richardson, 1920; Moore, 1957; and Trautman, 1957). It occurs in large schools in gravelly or sandy-bottom streams of moderate gradients, feeds on benthos and detritus, and is preyed upon by various predators (Hoyt, 1969). The objectives of this study were to determine the kinds and numbers of food organisms consumed by minnows of different lengths and during different seasons. Observations were made on the availability of food organisms in the stream and were related to their utilization by the minnows. STUDY AREA Plum Creek is a small tributary of the Salt River in north-central Kentucky (Shelby, Bullitt, and Spencer counties). It flows over a belt of Ordovician limestone in the western section of the Outer Bluegrass Region, and as a result of this stratigraphy the area exhibits a relatively flat, mildly karstic topography with few forests and soils of fair 1 Contribution 128 (New Series) from the Department of Biology, University of Louisville, Louisville, Kentucky 40208, from a doctoral dissertation submitted to the University of Louisville, June 1969. 2 Present address: Biology Department, Western Kentucky University, Bowling Green 42101.