Using the R Package, to assess landscape N removal in coastal catchments.

Background: Excess nitrogen (N) loading to coastal ecosystems impairs estuarine water quality. Land management decisions made within estuarine watersheds have a direct impact on downstream N delivery. Natural features within watersheds can act as landscape sinks for N, such as wetlands, streams and ponds that transform dissolved N into gaseous N, effectively removing it from the aquatic system.

A review of ecosystem services from edge-of-field practices in tile-drained agricultural systems in the United States Corn Belt Region.

Edge-of-field management practices that reduce nutrient pollution from tile drainage while contributing habitat and other ecosystem services are needed to enhance agricultural systems in the US Corn Belt Region. In this review, we identified edge-of-field and catchment scale agricultural conservation practices for intercepting and treating tile drainage. The reviewed conservation practices were (1) controlled drainage, also known as drainage water management (USDA-NRCS Code 554); (2) drainage water recycling (USDA-NRCS Code 447); (3) denitrifying bioreactors (USDA-NRCS Code 605); (4) saturated buffers (USDA-NRCS Code 604); and (5) constructed or restored wetlands designed for water quality improvement (USDA-NRCS Code 656) herein referred to as water quality wetlands.

Contaminant Exposure and Transport from Three Potential Reuse Waters within a Single Watershed.

Global demand for safe and sustainable water supplies necessitates a better understanding of contaminant exposures in potential reuse waters. In this study, we compared exposures and load contributions to surface water from the discharge of three reuse waters (wastewater effluent, urban stormwater, and agricultural runoff). Results document substantial and varying organic-chemical contribution to surface water from effluent discharges (e.

Potential of water quality wetlands to mitigate habitat losses from agricultural drainage modernization.

Given widespread biodiversity declines, a growing global human population, and demands to improve water quality, there is an immediate need to explore land management solutions that support multiple ecosystem services. Agricultural water quality wetlands designed to provide both water quality benefits and wetland and grassland habitat are an emerging restoration solution that may reverse habitat declines in intensive agricultural areas. Installation of water quality wetlands in the Upper Midwest, USA, when considered alongside the repair and modification of aging agricultural tile drainage infrastructure, is a likely scenario that may mitigate nutrient pollution exported from agricultural systems and improve crop yields.

Seasonal Distribution of Cyanobacteria in Three Urban Eutrophic Lakes Results from an Epidemic-like Response to Environmental Conditions.

Cyanobacterial communities of three co-located eutrophic sandpit lakes were surveyed during 2016 and 2017 over season and depth using high-throughput DNA sequencing of the 16S rRNA gene. All three lakes were stratified except during April 2017 when the lakes were recovering from a strong mixing event. 16S rRNA gene V4 sequences were parsed into operational taxonomic units (OTUs) at 99% sequence identity.

Enhanced streamflow prediction with SWAT using support vector regression for spatial calibration: A case study in the Illinois River watershed, U.S.

Accurate streamflow prediction plays a pivotal role in hydraulic project design, nonpoint source pollution estimation, and water resources planning and management. However, the highly non-linear relationship between rainfall and runoff makes prediction difficult with desirable accuracy. To improve the accuracy of monthly streamflow prediction, a seasonal Support Vector Regression (SVR) model coupled to the Soil and Water Assessment Tool (SWAT) model was developed for 13 subwatersheds in the Illinois River watershed (IRW), U.

Review of Watershed-Scale Water Quality and Nonpoint Source Pollution Models.

Watershed-scale nonpoint source (NPS) pollution models have become important tools to understand, evaluate, and predict the negative impacts of NPS pollution on water quality. Today, there are many NPS models available for users. However, different types of models possess different form and structure as well as complexity of computation.

Using SWAT to Evaluate Streamflow and Lake Sediment Loading in the Xinjiang River Basin with Limited Data.

Soil erosion and lake sediment loading are primary concerns of watershed managers around the world. In the Xinjiang River Basin of China, severe soil erosion occurs primarily during monsoon periods, resulting in sediment flow into Poyang Lake and subsequently causing lake water quality deterioration. Here, we identified high-risk soil erosion areas and conditions that drive sediment yield in a watershed system with limited available data to guide localized soil erosion control measures intended to support reduced sediment load into Poyang Lake.

Urban Stormwater: An Overlooked Pathway of Extensive Mixed Contaminants to Surface and Groundwaters in the United States.

Increasing global reliance on stormwater control measures to reduce discharge to surface water, increase groundwater recharge, and minimize contaminant delivery to receiving waterbodies necessitates improved understanding of stormwater-contaminant profiles. A multiagency study of organic and inorganic chemicals in urban stormwater from 50 runoff events at 21 sites across the United States demonstrated that stormwater transports substantial mixtures of polycyclic aromatic hydrocarbons, bioactive contaminants (pesticides and pharmaceuticals), and other organic chemicals known or suspected to pose environmental health concern. Numerous organic-chemical detections per site (median number of chemicals detected = 73), individual concentrations exceeding 10 000 ng/L, and cumulative concentrations up to 263 000 ng/L suggested concern for potential environmental effects during runoff events.

Quantifying the effects of surface conveyance of treated wastewater effluent on groundwater, surface water, and nutrient dynamics in a large river floodplain.

Restoration and reconnection of floodplain systems provide multiple societal and ecosystem benefits, while providing municipalities the opportunity to attempt alternative approaches to maintain infrastructure protection and function. In some restored floodplains, treated wastewater effluent discharge is redirected over land instead of directly into rivers to allow natural flow and infiltration, to facilitate restoration designs such as levee setback, and to provide additional freshwater to floodplain ecosystems. However, indirect discharge of treated effluent over land may pose risks to surface and groundwater when pollutants like excess nutrients enter the floodplain and undergo transformation.

Floodplain restoration increases hyporheic flow in the Yakima River Watershed, Washington.

Hyporheic exchange between a river channel and its floodplain region assists in mediating processes such as nutrient removal and temperature regulation. Floodplain restoration in the form of levee setbacks are often carried out to improve the hyporheic exchange. In this study Light Detection and Ranging (LiDAR) data were used along with the head data from observation wells and stage data from rivers to setup and calibrate a groundwater model for 458 km of area within Gap to Gap reach of the Yakima River, WA.

Vertically challenged: How disease suppresses vertical migration behavior.

Parasitic infections are increasingly recognized as influential forces in the migratory behaviors of hosts ranging from butterflies to whales. In aquatic zooplankton, diel vertical migrations (DVMs) are among the most recurrent behaviors with implications for predator-prey interactions, nutrient cycling, and energy flow, yet how parasitism affects such migrations remains an open question. Here, we tested the effects of sporangia cluster disease (SCD) on DVM of the large-bodied , which is often considered a key component of lake food webs.

Consumer Aggregations Drive Nutrient Dynamics and Ecosystem Metabolism in Nutrient-Limited Systems.

Differences in animal distributions and metabolic demands can influence energy and nutrient flow in an ecosystem. Through taxa-specific nutrient consumption, storage, and remineralization, animals may influence energy and nutrient pathways in an ecosystem. Here we show these taxa-specific traits can drive biogeochemical cycles of nutrients and alter ecosystem primary production and metabolism, using riverine systems that support heterogeneous freshwater mussel aggregations.

Aggregated filter-feeding consumers alter nutrient limitation: consequences for ecosystem and community dynamics.

Nutrient cycling is a key process linking organisms in ecosystems. This is especially apparent in stream environments in which nutrients are taken up readily and cycled through the system in a downstream trajectory. Ecological stoichiometry predicts that biogeochemical cycles of different elements are interdependent because the organisms that drive these cycles require fixed ratios of nutrients.

Ecological engineering practices for the reduction of excess nitrogen in human-influenced landscapes: a guide for watershed managers.

Excess nitrogen (N) in freshwater systems, estuaries, and coastal areas has well-documented deleterious effects on ecosystems. Ecological engineering practices (EEPs) may be effective at decreasing nonpoint source N leaching to surface and groundwater. However, few studies have synthesized current knowledge about the functioning principles, performance, and cost of common EEPs used to mitigate N pollution at the watershed scale.

Festering food: chytridiomycete pathogen reduces quality of Daphnia host as a food resource.

When parasitic infections are severe or highly prevalent among prey, a significant component of the predator's diet may consist of parasitized hosts. However, despite the ubiquity of parasites in most food webs, comparisons of the nutritional quality of prey as a function of infection status are largely absent. We measured the nutritional consequences of chytridiomycete infections in Daphnia, which achieve high prevalence in lake ecosystems (>80%), and tested the hypothesis that Daphnia pulicaria infected with Polycaryum laeve are diminished in food quality relative to uninfected hosts.

Effects of species diversity on community biomass production change over the course of succession.

Over the past decade an increasing number of studies have experimentally manipulated the number of species in a community and examined how this alters the aggregate production of species biomass. Many of these studies have shown that the effects of richness on biomass change through time, but we have limited understanding of the mechanisms that produce these dynamic trends. Here we report the results of an experiment in which we manipulated the richness of freshwater algae in laboratory microcosms.

Dining on disease: how interactions between infection and environment affect predation risk.

Despite growing interest in ecological interactions between predators and pathogens, few studies have experimentally examined the consequences of infection for host predation risk or how environmental conditions affect this relationship. Here we combined mesocosm experiments, in situ foraging data, and broad-scale lake surveys to evaluate (1) the effects of chytrid infection (Polycaryum laeve) on susceptibility of Daphnia to fish predators and (2) how environmental characteristics moderate the strength of this interaction. In mesocosms, bluegill preferred infected Daphnia 2-5 times over uninfected individuals.

Examination of physical and regulatory variables leading to small dam removal in Wisconsin.

The decision to remove or repair a dam depends on multiple variables, many of which encompass both physical and social factors. In Wisconsin, the Department of Natural Resources is mandated to inspect small dams every ten years. A safety inspection often acts as a trigger event to a dam removal or repair decision.