Tracking Outcomes and Metrics to Measure Progress

The Hypoxia Task Force has worked to set and report on metrics to better track progress towards nutrient loading and hypoxic zone reduction goals against the baseline period from 1980 – 1996. This work is key to understanding the effectiveness of the Gulf Hypoxia Action Plan strategies. In June 2026, the Task Force announced progress towards the interim target of a 20% reduction in both nitrogen and phosphorus delivered to the Gulf of America by 2025. The U.S. Geologic Survey (USGS) 2025 data showed that total nitrogen has decreased by 28% compared to the baseline but the interim target for total phosphorus has not yet been met (rather, phosphorus loads increased by 13%).

No single tool is perfect for measuring progress because of the wide variety of factors that influence nutrient loading from the MARB to the Gulf. Thus, the Task Force and its partners are working to measure basin-wide nutrient reductions at multiple scales through multiple tools, including the following:

• A decadal look at conservation effects through the USDA-supported Conservation Effects Assessment Project (CEAP) and USGS-supported SPAtially Referenced Regression On Watershed attributes (SPARROW) models and related assessment efforts;
• State, regional and basin-scale models, including but not limited to CEAP and SPARROW, that examine nutrients in the basin through source analyses;
• Statistical and other trend analyses of nutrient concentrations in the Mississippi/Atchafalaya River Basin (MARB) across multiple time-frames using data collected by states, USGS National Water Quality Assessment (NAWQA), EPA National Aquatic Resource Surveys (NARS), EPA National Nutrient Inventory, watershed groups, researchers, and those who use the Water Quality Portal for Nutrient Water Quality data (WQX);
• Biennial reports on point and nonpoint source trend information; and
• The annual NOAA hypoxia zone monitoring cruise, which is a key tool of the Task Force to measure progress.

The Task Force presents progress and ongoing efforts regularly at public meetings and through Reports to Congress. Subscribe to Task Force Newsletters to receive approximately quarterly updates on state and federal Task Force activities.

The Task Force has explored other tools that can be used to further measure progress. In 2020, the Task Force developed a compendium of tools to track conservation highlighting known technologies to track agricultural conservation in the United States. In 2024, the Task Force published a document sharing varied water quality assessments and approaches to track progress.

The Task Force tracks changes in nutrient loading from the MARB to the Gulf each year against the average total nitrogen and total phosphorus loads delivered to the Gulf during the baseline period from 1980 – 1996. To estimate these loads each year, the USGS uses the Weighted Regressions on Time, Discharge, and Season (WRTDS) methodology that 'normalizes' loads to average streamflow conditions. The WRTDS flow-normalized loads are a key metric used by the Task Force to evaluate progress towards nutrient reduction targets. These loads for total nitrogen and total phosphorus during the period from 1980 to 2025 can be viewed on USGS's website.