Big Sioux River Research Articles

Using environmental DNA to elucidate range expansion of bigheaded carp in two Missouri River tributaries in eastern South Dakota

AbstractObjectiveWe used environmental DNA (eDNA) sampling methods to determine the possibility of Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix (hereafter, bigheaded carp) range expansion above barriers to fish movement in two tributaries of the Missouri River in eastern South Dakota.MethodsWe collected water samples above and below two perceived barriers to fish movement: a natural chain of waterfalls in the Big Sioux River and a spillway at the downstream end of a man‐made reservoir in the Vermillion River. We used filtration methods to collect bigheaded carp eDNA from water samples and implemented real‐time quantitative polymerase chain reaction techniques to quantify the amount of eDNA in each sample. A total of 198 water samples and 35 field blanks were collected over 2 years (2021 and 2022).ResultWe detected bigheaded carp eDNA below both barriers in 2021 and 2022 and above the barrier in the Vermillion River during 2022. The median posterior prediction value for detecting eDNA below both barriers was 75.3% (95% credible interval [CrI] = 73.2–77.2%) for Bighead Carp eDNA and 54.2% (95% CrI = 51.5–56.4%) for Silver Carp eDNA. The probability of detecting eDNA above the barriers was significantly smaller: 1% (95% CrI = 0.01–1.10%) in the Big Sioux River and 1% (95% CrI = 0.01–1.30%) in the Vermillion River.ConclusionThe detection of positive samples above the spillway barrier in the Vermillion River provides the first evidence that bigheaded carp may have expanded their range to habitats upstream of their documented range in eastern South Dakota.

Progression along the invasion curve: silver carp growth slows temporally in two Missouri River tributaries

Silver carp (Hypophthalmichthys molitrix Valenciennes, 1844) have been invading North American rivers for decades, often altering zooplankton community structure and impacting native fishes. Silver carp invaded eastern South Dakota tributaries of the Missouri River in the early 2000s. Changes in dynamic rate functions can occur as invasive populations move to the latter stages of the invasion curve, but direct temporal assessments of silver carp populations are limited. Our objectives were to compare current growth of silver carp 1) between the Big Sioux and James rivers in South Dakota and 2) with previous growth recorded from the early stages of invasion (2009–2012) in these rivers. We collected silver carp in May and June of 2020–2022 using boat electrofishing and cast netting. We extracted lapilli otoliths for consensus aging from 99 and 82 silver carp from the Big Sioux and James rivers, respectively. We evaluated growth for each population using Bayesian von Bertalanffy models and compared posterior mean length at ages 2–5 to determine the probabilities of differences between rivers and with estimates from the introduction stage. Posterior estimated mean L∞ values were similar between the Big Sioux (714 mm) and James rivers (709 mm); however, the probability that the posterior mean K estimate was greater for silver carp in the James River (0.271) than the Big Sioux River (0.248) was >99.9%. Estimated mean lengths at age 2 were larger in the Big Sioux and James samples than during the introduction stage, but mean lengths at ages 3–5 were smaller. Changes in growth characteristics indicate that growth has slowed in the current establishment stage of invasion from the earlier introduction stage.

Heartland River: A Cultural and Environmental History of the Big Sioux River Valley ed. by Jon K. Lauck (review)

Heartland River: A Cultural and Environmental History of the Big Sioux River Valley ed. by Jon K. Lauck (review)

Heartland River: A Cultural and Environmental History of the Big Sioux River Valley

Heartland River: A Cultural and Environmental History of the Big Sioux River Valley

First molecular detection of the presence of honey bee viruses in insects, Varroa destructor mites, and pollinated plants in an isolated region of Armenia.

Recently, viral diseases of honey bees (Apis mellifera) have presented an increasing threat to beekeeping. This study aimed to examine the presence of honey bee viruses in Apis and non-Apis bee species, the mite Varroa destructor, and pollinated plants in Armenia. Sampling was performed in Tavush Province, in the northeast of the Republic of Armenia, from August to November 2019. Overall, 200 A. mellifera bees, 50 V. destructor mites, and 20 wasps were collected (corresponding to three bees, five mites, and 2-11 wasps in each investigated sample) and homogenized for RNA isolation and detection of viruses. Ten pollinated plants were taken from each plant, and 2 g of each sample was used for homogenization. In each investigated case Apis mellifera, Varroa destructor, Vespula germanica and plants received percentages of the virus presence. Six important honey bee viruses (acute bee paralysis virus [ABPV], deformed wing virus [DWV], A. mellifera norovirus [ANV], Lake Sinai virus-2 [LSV-2], Big Sioux River virus [BSRV], and A. mellifera filamentous virus [AmFV]) were detected in samples by polymerase chain reaction. Our results showed that DWV, ANV, and ABPV were the most common viruses in honey bees. All viruses were detected in wasps, but LSV-2 and ANV were present in almost all samples. Our results showed that almost all viruses were present in V. destructor. Although ANV is very common in honey bees, it did not appear in any mite samples. Our study indicates that viruses typically associated with honey bees were also actively infecting wasps. Our data suggest that the survival of viruses in plants can be an important source of seasonal transmission of viruses to bees. In addition, pollinated plants can potentially serve as reservoirs for honey bee viruses.

Interview with Jon Lauck

Interview with Jon Lauck

Variability of E. coli in streambed sediment and its implication for sediment sampling

E. coli is the number one cause for water quality impairments in rivers and streams in South Dakota and the United States. Stream bottom sediments can be a reservoir for bacteria, including pathogenic organisms and fecal indicator bacteria (FIB), due to the favorable conditions provided by sediments for survival. Despite this, little is known about the variability of E. coli in sediments which should be considered when developing a sampling regime. This study examines the spatial variability of E. coli in sediment across the stream cross-section, the temporal stability of E. coli in sediment samples, and the implications for sediment sampling and processing. Five locations were sampled for sediment E. coli along two tributaries to the Big Sioux River in eastern South Dakota, four along Skunk Creek (Sk1, Sk2, Sk3, and Sk4), and one in Sixmile Creek (SM). In Skunk Creek, site Sk1 has direct cattle access where the other three sites (Sk2, Sk3, and Sk4) are under Seasonal Riparian Area Management (SRAM), a strategy that limits the cattle access to the stream. E. coli concentrations in the sediment ranged from 4 to 997 CFU g−1 (8.5 × 102 to 2.1 × 105 CFU 100 mL−1). The highest and lowest E. coli concentrations observed were at sites Sk1 and Sk4, respectively. The E. coli concentration decreased from the upstream cattle crossing site (Sk1) through the downstream SRAM sites. Analyzing the stream cross-section analysis revealed no significant difference in E. coli concentration between the edge and the middle of the stream. Sediment samples can be held up to 24 h after sample collection in refrigerated conditions (37 °F) in the majority of cases (80%) without significant changes in E. coli concentrations. The sample size analysis indicated the spatial variability of E. coli across the stream cross-section is high and a single grab sample may not be able to provide adequate representation of E. coli concentrations in sediment without substantial error. The findings provide insight for designing E. coli monitoring projects and promote the awareness of unconventional sources of microbiological water quality impairment which are often overlooked.

Contributions of suspended load from Missouri River tributaries, southeast South Dakota, and northeast Nebraska: Building a sediment budget

AbstractSuspended sediment plays a critical role in riverine ecosystem health and river processes and is respondent to human alterations such as dams and increased land use. Gavins Point Dam, located on the Missouri River near Yankton, South Dakota, restricts upstream suspended load; yet, suspended sediment concentrations (SSC) increase when the river reaches Sioux City, Iowa. We determined the suspended load concentrations of seven tributaries of the Missouri River entering downstream of the dam. These data were collected from 2012 to 2019 during the summer months of May–July using a depth‐integrated sampler. Sediment rating curves were created based on discharge and SSC. We constructed a simple sediment budget, which indicated that the tributaries located in South Dakota contribute the bulk of the Missouri River's suspended load at ~80%, while the Nebraska tributaries contribute <5%. The remaining sediment is likely supplied by bank and bed erosion. Temporal changes were examined by comparing our recent measurements with historical data from USGS gaging stations on the James River and the Big Sioux River. Suspended sediment and discharge have increased by nearly an order of magnitude, potentially due to increases in precipitation and land use. Sediment budgets are useful resources for informing river management plans on a basin‐wide scale. Given the drastic, long‐term impacts of disruptions to sediment and flow regimes from dams and climate change, this research provides necessary groundwork for remediation efforts and river management.

Water 222Rn for evaluating the variation in groundwater inflows to discharge of the Big Sioux River in different flow periods

Knowledge of seasonal water sources can help for improved management strategies to sustain agricultural productivity and ecosystem-services in a basin. This study defines the distribution of gaining reaches and evaluates groundwater inflows into the Big Sioux River located in eastern South Dakota using 222Rn mass balance approach during two distinctly different flow periods. The groundwater inflows estimated for the middle catchment were higher (up to 12.8 m3/m/day) compared to the values estimated for the upper catchment (up to 0.3 m3/m/day) in the Big Sioux River basin during both low- and high-flow periods. During low-flow period, the overall cumulative groundwater inflow ranged between 2529 and 211,166 m3/day that corresponded to 5 and 53% contribution to the total flow rate. The inflow during high-flow period ranged between 2467 and 332,740 m3/day corresponding to 2 and 55% of the total flow rate. Despite having elevated cumulative groundwater inflow during high-flow period, the relative contribution of groundwater inflow into the river was high during the low-flow period (a mean of 24% evaluated for the low-flow period vs. 18% for the high-flow period), potentially associated with high meltwater contribution derived from the spring snowmelt during that period. These estimations are expected to provide a better knowledge on seasonal water resource allocations that may be crucial for better water resource management strategies for the Big Sioux River basin.

Next-Generation Sequencing on Insectivorous Bat Guano: An Accurate Tool to Identify Arthropod Viruses of Potential Agricultural Concern.

Viruses belonging to the Dicistroviridae family have attracted a great deal of attention from scientists owing to their negative impact on agricultural economics, as well as their recent identification as potential aetiological agents of febrile illness in human patients. On the other hand, some Dicistroviruses are also studied for their potential biopesticide properties. To date, Dicistrovirus characterized in African mainland remain scarce. By using High-Throughput Sequencing technology on insectivorous bat faeces (Hipposideros Caffer) sampled in a cave used by humans to collect bat guano (bat manure) as fertilizer in Zimbabwe, we characterized the full-length sequences of three Dicistrovirus belonging to the Cripavirus and Aparavirus genus: Big Sioux River Virus-Like (BSRV-Like), Acute Bee Paralysis Virus (ABPV), and Aphid Lethal Paralysis Virus (ALPV). Phylogenetic analyses of ORF-1 and ORF-2 genes showed a complex evolutionary history between BSRV and close viruses, as well as for the Aparavirus genus. Herewith, we provide the first evidence of the presence of Dicistrovirus in Zimbabwe and highlight the need to further document the impact of such viruses on crops, as well as in beekeeping activities in Zimbabwe which represent a crucial source of income for Zimbabwean people.

Soil Erosion Spatial Prediction using Digital Soil Mapping and RUSLE methods for Big Sioux River Watershed

A recent conversion of the grasslands to cropland degrading the soil quality (SQ), and impacting the soil erosion and crop productivity in the West Corn Belt (WCB) of the USA. The current study was conducted to estimate the spatial distribution of soil erosion at Big Sioux River (BSR) watershed scale using the Geographical Information System (GIS)-enabled Revised Universal Soil Loss Equation (RUSLE). Spatial data such as weather, a digital elevation model (DEM), land use maps and soils were used for assessment of soil erosion was downloaded from the easily available online sources. Data showed that about 7% of grassland acreage reduced from 2008 (24%) to 2015 (17%), whereas, about 7.4% of cropland acreage increased from 2008 (64.6%) to 2015 (72%) in the BSR watershed. This grassland conversion to cropland increased the soil erosion (estimated using the RUSLE model) from 12.2 T ha−1 year−1 in 2008 to 14.8 T ha−1 year−1 in 2015. The present study concludes that grassland conversion to cropland in the BSR watershed increased the soil erosion, therefore, management practices essential to be applied to reduce the erosion risk and various other ecosystem services.

Metagenomic analysis of bat guano samples revealed the presence of viruses potentially carried by insects, among others by Apis mellifera in Hungary.

The predominance of dietary viruses in bat guano samples had been described recently, suggesting a new opportunity to survey the prevalence and to detect new viruses of arthropods or even plant-infecting viruses circulating locally in the ecosystem. Here we describe the diversity of viruses belonging to the order Picornavirales in Hungarian insectivorous bat guano samples. The metagenomic analysis conducted on our samples has revealed the significant predominance of aphid lethal paralysis virus (ALPV) and Big Sioux River virus (BSRV) in Hungary for the first time. Phylogenetic analysis was used to clarify the relationship to previously identified ALPV strains infecting honey bees, showing that our strain possesses a close genetic relationship with the strains that have already been described as pathogenic to honey bees. Furthermore, studies have previously confirmed the ability of these viruses to replicate in adult honey bees; however, no signs related to these viruses have been revealed yet. With the identification of two recently described possibly honey bee infecting viruses for the first time in Hungary, our results might have importance for the health conditions of Hungarian honey bee colonies in the future.

Viral metagenomics of aphids present in bean and maize plots on mixed-use farms in Kenya reveals the presence of three dicistroviruses including a novel Big Sioux River virus-like dicistrovirus

BackgroundAphids are major vectors of plant viruses. Common bean (Phaseolus vulgaris L.) and maize (Zea mays L.) are important crops that are vulnerable to aphid herbivory and aphid-transmitted viruses. In East and Central Africa, common bean is frequently intercropped by smallholder farmers to provide fixed nitrogen for cultivation of starch crops such as maize. We used a PCR-based technique to identify aphids prevalent in smallholder bean farms and next generation sequencing shotgun metagenomics to examine the diversity of viruses present in aphids and in maize leaf samples. Samples were collected from farms in Kenya in a range of agro-ecological zones.ResultsCytochrome oxidase 1 (CO1) gene sequencing showed that Aphis fabae was the sole aphid species present in bean plots in the farms visited. Sequencing of total RNA from aphids using the Illumina platform detected three dicistroviruses. Maize leaf RNA was also analysed. Identification of Aphid lethal paralysis virus (ALPV), Rhopalosiphum padi virus (RhPV), and a novel Big Sioux River virus (BSRV)-like dicistrovirus in aphid and maize samples was confirmed using reverse transcription-polymerase chain reactions and sequencing of amplified DNA products. Phylogenetic, nucleotide and protein sequence analyses of eight ALPV genomes revealed evidence of intra-species recombination, with the data suggesting there may be two ALPV lineages. Analysis of BSRV-like virus genomic RNA sequences revealed features that are consistent with other dicistroviruses and that it is phylogenetically closely related to dicistroviruses of the genus Cripavirus.ConclusionsThe discovery of ALPV and RhPV in aphids and maize further demonstrates the broad occurrence of these dicistroviruses. Dicistroviruses are remarkable in that they use plants as reservoirs that facilitate infection of their insect replicative hosts, such as aphids. This is the first report of these viruses being isolated from either organism. The BSRV-like sequences represent a potentially novel dicistrovirus infecting A. fabae.

Use of geochemical tracers for estimating groundwater influxes to the Big Sioux River, eastern South Dakota, USA

Understanding the spatial distribution and variability of geochemical tracers is crucial for estimating groundwater influxes into a river and can contribute to better future water management strategies. Because of the much higher radon (222Rn) activities in groundwater compared to river water, 222Rn was used as the main tracer to estimate groundwater influxes to river discharge over a 323-km distance of the Big Sioux River, eastern South Dakota, USA; these influx estimates were compared to the estimates using Cl− concentrations. In the reaches overall, groundwater influxes using the 222Rn activity approach ranged between 0.3 and 6.4 m3/m/day (mean 1.8 m3/m/day) and the cumulative groundwater influx estimated during the study period was 3,982–146,594 m3/day (mean 40,568 m3/day), accounting for 0.2–41.9% (mean 12.5%) of the total river flow rate. The mean groundwater influx derived using the 222Rn activity approach was lower than that calculated based on Cl− concentration (35.6 m3/m/day) for most of the reaches. Based on the Cl− approach, groundwater accounted for 37.3% of the total river flow rate. The difference between the method estimates may be associated with minimal differences between groundwater and river Cl− concentrations. These assessments will provide a better understanding of estimates used for the allocation of water resources to sustain agricultural productivity in the basin. However, a more detailed sampling program is necessary for accurate influx estimation, and also to understand the influence of seasonal variation on groundwater influxes into the basin.

Artificial bee colony feature selection algorithm combined with machine learning algorithms to predict vertical and lateral distribution of soil organic matter in South Dakota, USA

ABSTRACTThe main purpose of this study, is to evaluate an advanced feature selection technique, artificial bee colony (ABC) algorithm; to reduce the number of auxiliary variables derived from a digital elevation model (DEM) and remotely sensed data (e.g. Landsat images). A combination of depth functions (e.g. power, logarithmic and spline) and data miner methods (artificial neural network: ANN and support vector regression: SVR) were applied for three-dimensional mapping of soil organic matter (SOM) in Big Sioux River watershed, South Dakota, USA. Unsurprisingly, the ABC feature selection algorithm indicated that remote sensing data (e.g. NDVI) are powerful predictors at soil surface, however, with the increasing soil depth, the terrain parameters (e.g. wetness index) became more relevant. Our findings from this study demonstrated that both the spatial models generally performed well. The mean R2 values calculated by 10-fold cross validation suggested that SVR and ANN models could explain approximately 50 and 57% of total SOM variability, respectively. However, predictive power of both models increased when ABC feature selection algorithm applied, particularly when it combined with the ANN model. Results showed that DSM approaches are very important and powerful tool to explain the 3D spatial distribution of SOM across the study watershed.

Discovery of Known and Novel Viral Genomes in Soybean Aphid by Deep Sequencing

The phytobiome includes not just cellular microorganisms, but also all viruses associated with plants: the virome. Plants and aphids exchange viruses regularly and efficiently; thus, the plant virome is tightly linked with the aphid virome. Yet, little is known about aphid viromes, particularly that of the soybean aphid (Aphis glycines), one of the most economically important pest insects of soybean. To sample the soybean aphid virome, and to seek new viruses as potential biological control agents, we employed next-generation sequencing. Genomes isolated from viruses in soybean aphids collected at four sites revealed many viruses, and six complete or nearly complete genomes were assembled. Most abundant were the picornavirus-like dicistroviruses Aphid lethal paralysis virus and Rhopalosiphum padi virus. We also sequenced the genome of a new dicistrovirus, Big Sioux River virus, fragments of which had been found previously in honey bee. Genome sequences that represent two entirely new virus families were obtained. These include an abundant tetravirus-like virus and a virus distantly related to cileviruses of plants and negeviruses of insects. Surprisingly, Cotton leafroll dwarf virus, a member of the genus Polerovirus, was found in soybean aphids from China, suggesting that the soybean aphid may be a vector of this virus. This virus had not been reported previously in China or in soybean. This study provides a peek into the rapidly expanding, largely unexplored world of insect viromes that will provide valuable knowledge for future understanding of plant−virus−vector interactions. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Streaming

36 WLT MAY–AUGUST 2017 The innovator isn’t important. It’s whoever has the watershed moment. – Travis Hedge Coke We haven’t slept since September. Some of us, since we remember. Not the real sleep, the deep-down cloud dreams. We do dream encoded loaded maze of meaning, circling consciousness, streaming before we are wakeful to undo, rearrange perspective , begin seeing. It is reason, dreaming. They’re shooting people. Water is life. In another time, not long ago, I might have found you face up in a field of silence among the stillbeautiful bodies of Dakota men. To speak for the land: even our history is against us here. – Karenne Wood, “To Keep Faith” Our texts and emails, cryptic. The liminal space we dwell in, funneling channel flow to stimulate strategy, support, to manifest our way of being, use ourselves as conduits to change the onslaught we muddle through. It is the plunther we feel that feeds impetus, writing, reading, breathing. We muster each agonizing proof as colonialism chiefs its way, no matter the era. The more insidious, the more it manages to find colluders, investment stakeholders. It’s day twenty in the electoral college coup new world order. Day five, the latest colonial figurehead-led coup, executive order inked, chased time from existence, from its place protecting water from awkward penetration by drills meant to inhabit the black snake seeping toxic ssssss, the millions of years old, sometimes hundreds of millions of years old anaerobic decomposition of thunder lizard deep beyond the airless brine water walls. The tyrant’s invested. Along with seventeen banks, hundreds of entities, with hunger for power and wealth despite the health of the planet or her people. Rubber bullets, concussion grenades, water cannons, pepper spray, tasers , brute force, and psychological torture on US and Western Hemispheric Tribal Nation citizens, including journalists covering protectors praying, singing, dancing, willing to sacrifice themselves to spare clean water. This is what we’ve come to in the colonial mad world. Not a step away from Wounded Knee, Sand Creek, from Mankato, since September they’ve blown up an arm, detached a retina, bloodied, bruised, frozen, battered, imprisoned, ethnic cleansing–like numbered, all for oil, for a pipe that will eventually deteriorate and leak, ruining water forever, for millions. You can’t drink oil. Water is life. I finger pelican bones, mollusk shells, A piece of down; I cherry pick – Tiffany Midge, “Oil Spill” It is said dinosaurs, the oil plume, left the world when a pelican opened his eyes and shot lightning and his mouth thundered. They left the world when they had grown so big everything else was endangered. They had outgrown the planet and the planet needed to survive, and has. The remnants of the lizard decomposition below us now, like all else, once inhabited the ground before ice age turned it over. It is deeply seeded into earth and not meant to see light of day in this world, this time we know on earth. Its entangled and hammered spirit seeps beneath us and fills a space that would be who knows what in the mystery of the planet if this tragedy had not befallen them. It is important to not reduce dinosaurs to lizards, or we cannot from studies or definitions alone tell them apart. It is important to remember lizards lived alongside dinosaurs, that species, like writers, Streaming by Allison Adelle Hedge Coke cover feature | puterbaugh essay WORLDLIT.ORG 37 fred jones jr . museum of art , the university of oklahoma , norman ; the james t . bialac native american art collection , 2010 America Meredith (Cherokee Nation), Current (2005), acrylic on steel, 18 x 18 in, part of the Greater Vehicle series 38 WLT MAY–AUGUST 2017 are not born all on the same day with the same scope and wants and do not die all at once even in times of mass extinction. a lone whale singing at a frequency of around 52 hertz has cruised the ocean since 1992. Its calls, despite being clearly those of a baleen, do not match those of any known species of whale, – Deborah Miranda, “Ishi at Large” Alongside Big Sioux River, a Missouri tributary, at the site...

Spatial and Temporal Evaluation of Hydrological Response to Climate and Land Use Change in Three South Dakota Watersheds

AbstractThis study analyzed changes in hydrology between two recent decades (1980s and 2010s) with the Soil and Water Assessment Tool (SWAT) in three representative watersheds in South Dakota: Bad River, Skunk Creek, and Upper Big Sioux River watersheds. Two SWAT models were created over two discrete time periods (1981‐1990 and 2005‐2014) for each watershed. National Land Cover Datasets 1992 and 2011 were, respectively, ingested into 1981‐1990 and 2005‐2014 models, along with corresponding weather data, to enable comparison of annual and seasonal runoff, soil water content, evapotranspiration (ET), water yield, and percolation between these two decades. Simulation results based on the calibrated models showed that surface runoff, soil water content, water yield, and percolation increased in all three watersheds. Elevated ET was also apparent, except in Skunk Creek watershed. Differences in annual water balance components appeared to follow changes in land use more closely than variation in precipitation amounts, although seasonal variation in precipitation was reflected in seasonal surface runoff. Subbasin‐scale spatial analyses revealed noticeable increases in water balance components mostly in downstream parts of Bad River and Skunk Creek watersheds, and the western part of Upper Big Sioux River watershed. Results presented in this study provide some insight into recent changes in hydrological processes in South Dakota watersheds. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.

Varroa destructor Macula-like virus, Lake Sinai virus and other new RNA viruses in wild bumblebee hosts (Bombus pascuorum, Bombus lapidarius and Bombus pratorum)

Pollinators such as bumblebees (Bombus spp.) are in decline worldwide which poses a threat not only for ecosystem biodiversity but also to human crop production services. One main cause of pollinator decline may be the infection and transmission of diseases including RNA viruses. Recently, new viruses have been discovered in honeybees, but information on the presence of these in wild bumblebees is largely not available.In this study, we investigated the prevalence of new RNA viruses in Bombus species, and can report for the first time Varroa destructor Macula-like virus (VdMLV) and Lake Sinai virus (LSV) infection in multiple wild bumblebee hosts of Bombus pascuorum, Bombus lapidarius and Bombus pratorum. We sampled in 4 locations in Flanders, Belgium. Besides, we confirmed Slow bee paralysis virus (SBPV) in wild bumblebees, but no positive samples were obtained for Big Sioux river virus (BSRV). Secondly, we screened for the influence of apiaries on the prevalence of these viruses. Our results indicated a location effect for the prevalence of VdMLV in Bombus species, with a higher prevalence in the proximity of honeybee apiaries mainly observed in one location. For LSV, the prevalence was not different in the proximity or at a 1.5km-distance of apiaries, but we reported a different isolate with similarities to LSV-2 and “LSV-clade A” as described by Ravoet et al. (2015), which was detected both in Apis mellifera and Bombus species. In general, our results indicate the existence of a disease pool of new viruses that seems to be associated to a broad range of Apoidae hosts, including multiple Bombus species.

Estimating the effects of potential climate and land use changes on hydrologic processes of a large agriculture dominated watershed

Land use and climate are two major components that directly influence catchment hydrologic processes, and therefore better understanding of their effects is crucial for future land use planning and water resources management. We applied Soil and Water Assessment Tool (SWAT) to assess the effects of potential land use change and climate variability on hydrologic processes of large agriculture dominated Big Sioux River (BSR) watershed located in North Central region of USA. Future climate change scenarios were simulated using average output of temperature and precipitation data derived from Special Report on Emission Scenarios (SRES) (B1, A1B, and A2) for end-21st century. Land use change was modeled spatially based on historic long-term pattern of agricultural transformation in the basin, and included the expansion of corn (Zea mays L.) cultivation by 2, 5, and 10%. We estimated higher surface runoff in all land use scenarios with maximum increase of 4% while expanding 10% corn cultivation in the basin. Annual stream discharge was estimated higher with maximum increase of 72% in SRES-B1 attributed from higher groundwater contribution of 152% in the same scenario. We assessed increased precipitation during spring season but the summer precipitation decreased substantially in all climate change scenarios. Similar to decreased summer precipitation, discharge of the BSR also decreased potentially affecting agricultural production due to reduced future water availability during crop growing season in the basin. However, combined effects of potential land use change with climate variability enhanced for higher annual discharge of the BSR. Therefore, these estimations can be crucial for implications of future land use planning and water resources management of the basin.