Skip to main content
Advanced Search

Filters: Tags: Nutrient loading (X)

5 results (13ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
This dataset was developed in partnership with the Tennessee Department of Environmental Conservation to determine the susceptibility of selected Tennessee reservoirs to eutrophication and potential harmful algal blooms. A R script, based on recursive partitioning and the model-based boosting routine, was used to generate regression trees that grouped Tennessee reservoirs into five endpoints along individual low-to-high gradients of Secchi depth and chlorophyll a concentrations (Green, et al, 2021; Heal and Green, 2021). Input data for these reservoirs were obtained from SPAtially Referenced Regression On Watershed (SPARROW) attributes models that estimate total phosphorus and total nitrogen loads in Tennessee water...
thumbnail
Streamflow and phosphorus concentrations were monitored in the Assabet River in central Massachusetts in order to evaluate concentrations and loads in the river before, during, and after changes in the amount of total phosphorus that was discharged to the river from three wastewater-treatment plants. At four locations the U.S. Geological Survey collected weekly flow-proportional, composite samples of water from the Assabet River for analysis of concentrations of total phosphorus and orthophosphate. Streamflow and concentration data were used to estimate total phosphorus and orthophosphate loads in the river and compare them with total phosphorus load outputs from three wastewater-treatment plants. Data were collected...
In temperate latitudes, toxic cyanobacteria blooms often occur in eutrophied ecosystems during warm months. Many common bloom-forming cyanobacteria have toxic and non-toxic strains which co-occur and are visually indistinguishable but can be quantified molecularly. Toxic Microcystis cells possess a suite of microcystin synthesis genes (mcyA–mcyJ), while non-toxic strains do not. For this study, we assessed the temporal dynamics of toxic and non-toxic strains of Microcystis by quantifying the microcystin synthetase gene (mcyD) and the small subunit ribosomal RNA gene, 16S (an indicator of total Microcystis), from samples collected from four lakes across the Northeast US over a two-year period. Nutrient concentrations...
thumbnail
For State agencies and other water-resources managers, determining which waterbodies to allocate limited funds for protection and restoration while also maximizing cost benefit is challenging. This data release contains trophic state designations determined from secchi depth, and concentrations of chlorophyll a and microcystin at 232 lakes and reservoirs having a surface area of greater than 0.1 square kilometer in watersheds that drain to the Atlantic and eastern Gulf of Mexico coasts of the United States and in watersheds within the Tennessee River Basin. Estimates of nutrient loading (nitrogen and phosphorus, Hoos and others, 2013; Moorman and others, 2014) and flushing rates were combined with waterbody morphometry...
thumbnail
Description of Work The Great Lakes ecosystem has undergone major changes over the last two decades related to the invasion of Dreissenid mussels, increased water clarity, increased benthic algae and associated water quality problems. For reasons not yet entirely understood, and that have bi-national significance, water column total phosphorus has not significantly increased over the last decade but the relative percent of the more biologically available dissolved phosphorus has increased. The filtering action of Dreissenid mussels has been shown to increase concentrations of dissolved phosphorus in the water column immediately above mussel beds and this had been hypothesized as one explanation for the increase...


    map background search result map search result map Understanding Nutrient Loading Impacts on Lake Ontario Nearshore Waters at the Niagara River Connecting Channel Streamflow and total phosphorus and orthophosphate data for samples collected in and near the Assabet River, Massachusetts, October 2008 through April 2014 Nutrient loading, flushing rate, and lake morphometry data used to identify trophic states in selected watersheds of the eastern and southeastern United States Regression tree datasets used to identify trophic states in Tennessee reservoirs Streamflow and total phosphorus and orthophosphate data for samples collected in and near the Assabet River, Massachusetts, October 2008 through April 2014 Regression tree datasets used to identify trophic states in Tennessee reservoirs Understanding Nutrient Loading Impacts on Lake Ontario Nearshore Waters at the Niagara River Connecting Channel Nutrient loading, flushing rate, and lake morphometry data used to identify trophic states in selected watersheds of the eastern and southeastern United States