Getting Started
Welcome to Great Lakes to Gulf: Tracking nutrient trends in the Mississippi River Basin. This page provides an overview of the information you can find on the site. We also provide audience-focused suggestions about where you might want to get started exploring the pages, although you are welcome to start anywhere that fits your needs.
For Scientists
Nutrient Trends
Each state has its own water quality challenges and questions to answer, which means that they often use different monitoring approaches, and data analysis methods. This makes it hard to compare trends from state to state.
Our objective was to conduct scientifically based and methodologically consistent nutrient trend analyses for the 20-year period from 2000 to 2020 for sites throughout the MARB. Trends magnitudes and their significance were computed using the Weighted Regression on Time, Discharge, and Season (WRTDS) coupled to a bootstrap test that calculates the probability that the trend shown is real. Trend results were correlated with land cover, drainage area, relief, and upstream dam storage.
The methods used can be referenced at: Hirsch, R. M., Moyer, D. L. & Archfield, S. A. 2010. Weighted regressions on time, discharge, and season (WRTDS), with an application to Chesapeake Bay river inputs. JAWRA Journal of the American Water Resources Association, 46, 857-880.
This standardization allows us to compare trends between the states within the MARB. It also reveals the gaps in location of monitoring stations as well as the need for greater flow monitoring to correlate with water quality.
Nutrient Trends DashboardExplore Big Data
We present nutrient and water quality data from the sources below. We also show geospatial layers of characteristics related to the flow of nutrients from land to water, such as land use, tile drainage, fertilizer use, conservation practice locations, and conservation funding.
- Water Quality Portal (WQP): The WQP is the premiere source of discrete water-quality data in the United States and includes publicly available water-quality data from the United States Geological Survey (USGS), the Environmental Protection Agency (EPA), and over 400 state, federal, tribal, and local agencies. We have done the work of distilling the nitrogen and phosphorus data for you so that you may more easily conduct your own analyses.
- USGS Water Quality Data: This data source provides multiple parameters of water quality such as dissolved oxygen, turbidity, water temperature, nutrient data, and more. Measurements of flow are also associated with the water quality data.
- USGS Super Gage Network: In-stream water-quality and flow readings are collected at the super gage sites every 15 minutes via satellite, transmitted hourly, and processed into a national database. This real-time data can inform people of stream conditions for various uses and public safety.
For Advocates
The 12 Hypoxia Task Force (HTF) states are working to reduce nutrient pollution and improve water quality in the Mississippi-Atchafalaya River Basin (MARB). Determining whether water quality in a given area within a state or region is improving is a complex task. Each state tries to answer this question by quantifying nutrient trends, but they do so at various scales and time periods and using multiple statistical and scientific methods, making it challenging to compare trends across the entire MARB. Our Nutrient Trends Dashboard provides a simple visualization of comparable nutrient trends across the MARB.
Nutrient Trends DashboardBut trends don’t tell the whole story. By exploring the State Efforts Dashboard, you can see how each state is approaching the challenge of nutrient reduction in their waterways. We have also provided a summary table of the similarities and differences in the state approaches to nutrient loss reduction and links to available resources, including: State Nutrient Loss Reduction Plans, Nutrient Dashboards, and Additional Water Quality Resources.
State Efforts DashboardFor Policy Makers
The Mississippi River and its tributaries supply drinking water, facilitate transportation, offer recreation opportunities, and provide critical habitat for a diverse array of plants and wildlife. But the river and its tributaries are degraded by high concentrations of nitrogen and phosphorus from point and nonpoint sources. The 12 Hypoxia Task Force (HTF) states are working to reduce concentrations of nutrients in our waterways to safeguard public health, improve the quality of drinking water, protect aquatic life and prevent harmful algal blooms as well as to reduce the size of the Hypoxic Zone in the Gulf.
The goal is to reduce harmful nutrient levels in the Mississippi River Basin, but it takes time to see results from nutrient loss reduction efforts. Monitoring long term nutrient trends is one way to measure progress.
Nutrient Trends DashboardGLTG shows nutrient levels and long-term trends throughout the Mississippi/Atchafalaya River Basin (MARB), suggests relationships between these observed trends and conservation indicators and practices, and serves as an information hub about state efforts to improve water quality. This information can help you track the effectiveness of nutrient reduction efforts at federal, state, and local levels and inform future nutrient loss reduction work.