Toxics | Invasives | Nonpoint | Habitat | Foundations
Focus Area 1
Channel Island Spawning Reef - Saginaw Bay
The Great Lakes Fishery Commission joined a Regional Habitat Partnership with the National Oceanic and Atmospheric Administration Office of Habitat Conservation with the goal to protect, restore, and improve fish habitat across the Great Lakes basin. Restoration of fish habitat in Saginaw Bay is considered a priority action in Lake Huron to accomplish this goal.
Construction of the Channel Island Reef began on September 8, 2025, and was completed on October 10, 2025. A barge deposited over 20,000 tons of natural limestone cobble from a local quarry on the bay floor to form a long, narrow rock mound. The new 2.5-acre reef is located 0.5 miles east of Channel Island, 2 miles from the mouth of the Saginaw River and is approximately 570 feet long and 190 feet wide. It rises approximately 3–4 feet above the existing lake bottom and sits at least 5.5 feet below the water’s surface, even when water levels are low. Boaters and anglers should exercise caution when navigating near the new reef. Construction of the new reef reintroduces the rocky habitat that native fish like lake whitefish and walleye once relied on to spawn—habitat that had all but vanished owing to sedimentation in the bay.
A variety of grant funds supported construction of Channel Island Reef, demonstrating broad confidence and shared investment in this project. These funding sources are the National Oceanic and Atmospheric Administration, Great Lakes Restoration Initiative, Great Lakes Fish and Wildlife Restoration Act, National Fish and Wildlife Foundation—Coastal Resilience Fund, and Dow Chemical Natural Resources Damage Assessment and Restoration settlement money, which supported feasibility studies, construction, and ongoing monitoring.
Built through community collaboration and with support from state, federal, and local partners, the Channel Island Reef will provide critical spawning grounds for native fish, complement the successful offshore Coreyon Reef, and help ensure that Saginaw Bay’s fisheries remain healthy, resilient, and productive.
Focus Area 2
Invasive Crayfish Collaborative rolls out new crayfish curriculum
Crayfish are frequently found in science classrooms as a teaching tool. But they can pose a threat if they are released into local waters because non-native species can push out native crayfish. A new curriculum from Illinois-Indiana Sea Grant’s Invasive Crayfish Collaborative (ICC) brings that lesson directly to teachers and students.
The ICC is a GLRI-funded initiative focused on improving collective management and public engagement capabilities through new crayfish research and engagement projects. The new curriculum will help educators across the Great Lakes region engage students in thinking critically about crayfish and freshwater ecosystems. Beyond the classroom, the lessons invite students to participate in the ICC’s crayfish study. Students can catch, identify, and report crayfish species in their respective areas on iNaturalist, a citizen science platform. This effort helps managers understand the crayfish distribution across the Great Lakes region
Educators were trained on the curriculum at a spring 2025 workshop in partnership with the National Park Service, Indiana Dunes Learning Center, and Center for Great Lakes Literacy. Since then, over 1,200 youth have participated in the crayfish lessons, including field sampling.
Focus Area 3
Development and transition to operations of a Lake Erie Harmful Algal Bloom Toxin Risk Forecast
Toxic harmful algal blooms (HABs) have been a recurring summer feature in western Lake Erie since the 2000s. Dominated by the cyanobacterium Microcystis aeruginosa, the HAB often contains toxic compounds known as microcystins. In an effort to mitigate the impacts of HABs and associated toxins on the Lake Erie coastal community, NOAA produces information products, and continues to research, develop, and transition new products to operations, supported in part by GLRI funds.
Building on NOAA’s 2020 Lake Erie HAB Forecast and ten years of observations of microcystins and chlorophyll-a from GLRI- and NOAA-funded monitoring programs, NOAA and partners developed a toxin risk statistical model relating a bloom’s chlorophyll-a concentration to its probability of exceeding the recreational advisory level of microcystins (8 micrograms per liter). The project team assessed two versions of the statistical model, using cross-validation over a ten-year hindcast period, and found that averaged predictions from the two methods performed better than either one alone. NOAA plans to operate a demonstration version of the Lake Erie HAB Toxin Risk Forecast in 2026, and obtain stakeholder feedback, with a public version of the operational forecast planned for June 2027.
Focus Area 4
New environmental sensitivity index data for Lake Michigan
A new dataset and updated Environmental Sensitivity Index (ESI) maps are now available for Lake Michigan, providing a critical tool for oil spill preparedness and response in the Great Lakes region. This new Lake Michigan ESI data, which replaces the previous 1993-1994 data, can be downloaded and viewed in Great Lakes ERMA®. In addition to the recently published data for Lake Michigan, NOAA’s Office of Response and Restoration (OR&R) has begun updating the ESI datasets for Lakes Superior and Huron, which were last updated in 1994. The updates will also include the Straits of Mackinac and the St. Clair-Detroit River system, last updated in 2019. The NOAA OR&R’s ESI program maps sensitive biological and human-use resources, classifies shorelines, and assigns vulnerability rankings based on a shoreline’s sensitivity to oil and chemical spills. These products, in addition to other efforts NOAA OR&R is advancing, improve planning and decision-making for environmental response agencies, helping to protect sensitive and rare habitats and inform restoration investments in the Great Lakes.
Since 2019, with funding from GLRI and other partners, NOAA OR&R has released updated ESI data for Lake Erie, the St. Marys River, the St. Lawrence River, the Straits of Mackinac, the St. Clair-Detroit River System, and Lake Ontario. Once all updates are complete, the Great Lakes ESI data will cover over 2,000 miles of shoreline and produce more than 200 maps, improving coastal resilience in the Great Lakes, where busy shipping routes and pipelines, including the 645-mile-long Enbridge Line 5 oil pipeline, support a massive economy. This vital commerce generates $50 billion in annual economic activity, supports between 35 and 40 million tons of cargo, and provides more than 356,000 jobs in the region.
Focus Area 5.1
Students research and contribute to Lake Erie watershed health
NOAA’s Great Lakes Bay Watershed Education and Training (B-WET) supports experiential, place-based learning for K-12 students by providing educational grants to organizations across the basin, such as the University of Toledo’s project, Engaging K-12 Students in Authentic Watershed Experiences, Science and Stewardship: Reconnecting to the Land at Earth Heart Farms. This B-WET funded project connected Toledo-area students and teachers to the land at Earth Heart Farms (EHF) in Oak Harbor, Ohio. The project integrated outdoor learning experiences and field-data collection at the farm into the school’s existing science curriculum, empowering students to conduct hands-on scientific inquiry into the roles native grasslands and wetlands play in mitigating Harmful Algal Blooms (“HABs”) in Lake Erie.
Throughout the school year, students collected environmental data through soil core testing, water testing, atmospheric observations, and biodiversity observations. Collected data contributed to the farm and to the GLOBE Program, a citizen-science database and NOAA partner. In addition, students completed stewardship projects focused on habitat restoration at Earth Heart Farms, related to EHF controlled burning and mowing vegetation, seeding and maintaining riparian buffers, and wetland excavation. Students expressed their learning through supplemental activities such as journaling, writing poetry, and starting native plant gardens at their schools which they continue monitoring on the GLOBE platform. This multidisciplinary learning approach, supported by over twenty conservation partners and visiting artists, helped students both build Science, Technology, Engineering, and Math (STEM) skills and foster a personal connection to nature. By its conclusion in April 2025, the project successfully engaged over 1,500 students and provided professional development for 34 Ohio teachers.
Focus Area 5.2
Evolving cyanobacterial “toxins” during blooms in Lake Erie
Collaborative research conducted by NOAA, USGS, and the University of Michigan (2016–2022), published in The ISME Journal offsite link, demonstrates that cyanobacterial blooms consist of a complex "chemical soup." This diverse assemblage of compounds extends beyond traditionally monitored toxins, posing multifaceted risks to both ecological stability and public health. While monitoring efforts have historically focused on microcystins, high-resolution metagenomic and metabolomic analyses reveal a complex chemical diversity of potentially toxic cyanobacterial compounds throughout the bloom season. The seven-year assessment indicates that as environmental conditions evolve over the bloom season, a chemical succession also occurs, leading to potential new harmful impacts to the ecosystem. While Microcystis tends to dominate early in the bloom season when water is warmer and nitrogen levels are high, later in the season, as temperatures drop, Dolichospermum becomes more prevalent. During this shift, the dominant chemical compounds also progress in distinct phases: Phase 1: Microcystins; Phase 2: Anabaenopeptins and aeruginosins; and Phase 3: Aerucyclamides. Current water quality assessments prioritize microcystin detection but as the bloom transitions rather than disappears, human and ecosystem exposure to secondary chemical compounds may occur. This research highlights how seasonal nutrient reduction and fluctuating environmental conditions drive the selection of cyanobacterial species, their toxin profiles, and the resulting impact on overall ecosystem health.
This discovery necessitates a fundamental shift in our approach to cyanotoxin risk and monitoring. Current reliance on microcystin testing alone creates a significant monitoring gap, potentially leaving secondary but hazardous chemicals undetected. By integrating a broader chemical profile into monitoring programs, we can enhance the management of freshwater blooms to better protect public health. These findings have impacted other GLRI efforts, such as ‘Decision support tools to link nutrient controls to harmful algal bloom development, toxin production, and demise’ that now include monitoring this suite of chemical compounds throughout the bloom season.
Winter observations
Winter conditions in the Great Lakes are still not well understood because harsh weather and ice often make it unsafe or impossible for research vessels to operate. As a result, we also know less about how winter conditions affect the lakes during the rest of the year—and how summer and fall conditions may shape what happens in winter. In the central basin of Lake Erie, wintertime growth of algae that settle to the bottom sediment is a potentially important driver of summertime sediment oxygen demand that leads to hypoxia in the central basin. Summer hypoxia can have a negative impact on drinking water processing for more than 2 million residents along the coast of Lake Erie. Rates of organic carbon deposition from diatoms growing in winter can be several-fold higher than in other seasons. In turn, that winter production could depend on phosphorus released during summertime hypoxia, although the fate of the phosphorus and organic matter has not been measured continuously through the seasonal cycles.
With support from GLRI Focus Area five and Cooperative Science and Monitoring Initiative, researchers at University of Michigan’s Cooperative Institute for Great Lakes Research (UM-CIGLR) and NOAA’s Great Lakes Environmental Research Laboratory (NOAA-GLERL) deployed moorings equipped with sensors to continuously record conditions and a sediment trap and Remote Access Sampler (McLane Research Laboratories) to capture settling algae, nutrients like phosphorus, and DNA every 5 to 11 days. Since October 2024, these moorings have captured the complete seasonal thermal cycle of the lake, including the important transition from summer stratification into fall and early winter. Preliminary results show that this time of year, late October through December, had unexpectedly high concentrations of sediment and algae. Those instrument measurements and samples are being paired with research vessel cruises in late fall and early spring performed by University of Windsor (Ontario, Canada) and Bowling Green State University (Bowling Green, OH). Observations from this project will help improve predictions for how hypoxia responds to lake management actions and could inform future hypoxia models to provide early warning to drinking water intakes.
