Advancing Harmful Algal Bloom Research in Presque Isle Bay

Harmful algal blooms (HABs) have become one of the most pressing water quality challenges facing lakes, reservoirs, and coastal waters across the United States. While algae and cyanobacteria are natural components of aquatic ecosystems, certain environmental conditions can trigger rapid growth that results in dense blooms.

HABs can cause significant water quality issues, often forming a visible and sometimes odorous scum on the surface of the water. They can produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms. HABs also negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes and waterways.

HABs in Lake Erie and Presque Isle Bay

The Great Lakes are among the world’s most important freshwater resources, supporting drinking water, recreation, tourism, commerce, and diverse aquatic ecosystems. HABs have emerged as a significant water quality challenge in many Great Lakes communities, including the Presque Isle Bay region of Erie, Pennsylvania.

Presque Isle Bay and the surrounding nearshore waters periodically experience HAB events that affect recreation, ecological health, and water quality. Some blooms also produce cyanotoxins that pose risks to people, pets, and wildlife.

Following significant bloom activity in Presque Isle Bay in 2013, regional agencies, researchers, and community organizations expanded efforts to better understand HAB conditions and provide timely information to the public. Among the leaders in that effort has been the Regional Science Consortium (RSC), which has monitored cyanobacteria and cyanotoxins throughout the Presque Isle region for more than a decade. Through weekly sampling efforts at beaches, marinas, parks, drinking water facilities, and other nearshore locations, RSC has developed an extensive dataset documenting bloom occurrence, cyanotoxin concentrations, and changing conditions across the region. The organization has also become an important source of public education and outreach, helping residents, visitors, and resource managers better understand HAB risks and respond to changing conditions.

This combination of long-term monitoring, scientific expertise, and local knowledge has established a strong foundation for the next step: evaluating innovative management strategies that may help reduce HAB impacts before they become widespread.

A Partnership Focused on Innovative Solutions

Building on RSC’s longstanding monitoring program, Princeton Hydro and RSC are collaborating on the implementation of a technology demonstration project. The project is funded by the U.S. Army Corps of Engineers (USACE) Engineer Research and Development Center (ERDC). Erie-Western PA Port Authority provides site access for staging and field implementation activities within Presque Isle Bay.

Where monitoring programs help us understand when and where blooms occur, this effort is focused on exploring a practical management question: can HABs be controlled using a non-pesticidal approach that physically removes cyanobacterial cells from the water column?

The collaboration brings together Princeton Hydro’s expertise in HAB management, water quality restoration, applied limnology, and water resources management with RSC’s extensive knowledge of local bloom conditions, cyanotoxin monitoring and Lake Erie’s ecosystems. By combining these strengths, the team is evaluating whether an innovative treatment strategy can provide resource managers with an additional tool for addressing HABs in vulnerable nearshore areas.

One focus of the technology demonstration is laponite, a synthetic nanoscale clay that has shown promise in laboratory testing as a means of removing cyanobacteria from the water column. Unlike traditional algicides that kill algae directly, laponite works through a physical removal process. When introduced into the water, the clay particles bind with suspended cyanobacterial cells, promoting coagulation and flocculation. As the resulting particles settle, cyanobacteria are removed from the water column and transported to bottom sediments where natural biological and environmental processes contribute to their breakdown.

Because laponite works through a physical binding and settling process, it removes the biomass and associated nutrients from the water column. This differs from chemical algicides, which work by lysing the cyanobacteria cells in place and can result in the potential release of toxins and nutrients near the surface. As a result, laponite may reduce the risk of unintended impacts to non-target organisms and other ecological effects associated with chemical treatments.

The first phase of the demonstration project involves the application of laponite at a mesocosm scale in Presque Isle Bay. A mesocosm is an experimental ecosystem that mimics the natural environment in a controlled setting. A mesocosm can be thought of as a link between controlled laboratory settings and uncontrolled natural environments. This phase of the project allows for the team to examine potential impacts of laponite on non-target organisms in a small, confined setting.

Six circular limnocorrals with a diameter of 3.0 meters were installed in the Perry’s Landing section of Presque Isle Bay. Each limnocorral has a clear, impervious tube that extends from the surface to the lake bottom and is sealed against the sediment with anchors. The limnocorrals have no bottom on the inside, allowing for direct contact with the sediment. Laponite was applied to three of the limnocorrals while the other three serve as controls. There is one sampling station in each limnocorral, and an additional three sampling stations just outside of the limnocorral to serve as a limnocorral-controls.

This ERDC-funded demonstration project provides an opportunity to evaluate the effectiveness, practicality, and potential limitations of laponite applications in active HAB environments within Presque Isle Bay. The demonstration also includes comprehensive water quality monitoring, cyanotoxin analyses, phytoplankton assessments, sediment characterization, incubation studies, molecular analyses, and statistical evaluation. These efforts help quantify treatment performance while also providing insight into how site conditions may influence results.

As part of the incubation studies, water and sediment samples are collected from treatment and control areas and brought to Princeton Hydro’s biological laboratory for analysis. These studies help identify overwintering cyanobacteria present within sediments and evaluate their potential to contribute to future bloom development. By comparing samples collected before and after treatment, the team can better understand whether management actions may influence not only active blooms in the water column but also the reservoir of cyanobacteria capable of fueling blooms in subsequent seasons.

The second phase of this project may involve a larger laponite application in Perry’s Landing during the 2027 growing season as part of a full field scale demonstration. The results from the limnocorral application will be examined and shared with all relevant regulators and stakeholders before the potential full field application.

Featured in Erie News Now

The project was recently highlighted by Erie News Now, which explored the partnership between Princeton Hydro and the Regional Science Consortium and the effort to evaluate innovative HAB management strategies in Presque Isle Bay. In the article, Dr. Jeanette Schnars, Executive Director of the Regional Science Consortium, emphasized the importance of understanding both the causes and impacts of HABs and ensuring communities have access to the information they need to protect people, pets, and local water resources.

Click here to read the article now.

Princeton Hydro is proud to partner with the Regional Science Consortium, USACE ERDC, and Erie-Western PA Port Authority on this innovative effort and grateful for the opportunity to contribute to the advancement of HAB management strategies in Lake Erie and beyond. As the project progresses, we look forward to sharing updates, findings, and lessons learned. Stay tuned!

In addition to our work with the RSC and ERDC in Lake Erie, our team is also leading an ERDC-funded technology demonstration at Lake Hopatcong, New Jersey’s largest lake, focused on evaluating innovative treatment strategies for controlling nearshore HABs. While each waterbody presents its own unique challenges, both projects share a common goal: advancing practical, effective, and environmentally responsible tools that can help communities better understand, manage, prevent, and reduce the impacts of HABs.

Click here to learn more about our Lake Hopatcong technology demonstration project.

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