About the Project

The St. Louis River Estuary, located at the headwaters of Lake Superior, has undergone extensive remediation and restoration following more than a century of pollution and habitat degradation. As the estuary approaches its anticipated delisting as a Great Lakes Area of Concern by 2030, new environmental stressors are raising concerns about its long-term health. In particular, cyanobacteria blooms, or harmful algal blooms (HABs), have emerged as a growing threat. This project was developed to better understand these challenges and to create a collaborative, science-based monitoring strategy for the estuary. The project findings revealed that environmental conditions, especially nitrogen concentrations affected by hydrologic conditions, strongly influence bloom dynamics, including bloom timing and composition.

About this Resource

This data package supports the project Building a Collaborative Water Quality Monitoring Strategy for a Changing St. Louis River Estuary. Led by the Lake Superior National Estuarine Research Reserve (LSNERR) and University of Minnesota’s Natural Resources Research Institute (NRRI), this project produced a data package that includes 2022–2024 water quality, phytoplankton, and winter dissolved oxygen observations from eight estuary “hotspot” locations.

Sampling captured seasonal variability and cyanobacteria bloom events. All samples were collected using standardized field and laboratory protocols. This data package can be used to evaluate spatial and temporal patterns in water quality and phytoplankton dynamics, assess predictors of cyanobacterial blooms, and monitor winter under-ice hypoxia in the St. Louis River Estuary. It is well-suited for research on nutrient-bloom relationships, seasonal and spatial ecological shifts, and long-term monitoring strategy development. The dataset description contains more information about the data, including sample collection methods and locations.

Data access and archival: the data package is available at the Environmental Data Initiative (EDI) Data Portal.

Questions about these datasets can be directed to: Hannah Nicklay, Lake Superior National Estuarine Research Reserve, [email protected]