Preparing for Potential Harmful Algal Blooms: An Urgent Call to Action for NJ’s Lakes and Reservoirs

By Dr. Fred Lubnow, Senior Technical Director of Ecological Services

As we reflect on the winter of 2023-2024, it’s evident that New Jersey experienced another unusually mild season, mirroring the winter of 2022-2023. Notably, Lake Hopatcong, located in Sussex and Morris Counties, remained virtually ice-free throughout the winter, with only a brief period of minor ice formation in early January. This pattern was not isolated to Lake Hopatcong; many lakes across the state and the broader Mid-Atlantic region exhibited similar ice-free conditions. Such conditions can lead to increased algal and plant growth earlier in the year.

Adding to this, from January to early June 2024, 15 of New Jersey’s 21 counties recorded precipitation levels 26% to 50% higher than their long-term averages. The remaining six counties, predominantly in the southern part of the state, had precipitation increases of 11% to 25% above their long-term normals. This heightened precipitation is significant as it can transport nutrients, most notably phosphorus and nitrogen, into water bodies, potentially fueling the growth of algae.

Compounding these factors, long-range climate models and trends suggest that the summer of 2024 could rank among the hottest on record. The combination of a mild winter, increased precipitation, and anticipated high summer temperatures sets the stage for conditions similar to those experienced in 2019, a year marked by widespread harmful algal blooms (HABs) in numerous lakes.

HABs, characterized by rapid overgrowths of cyanobacteria, present serious challenges to water quality and aquatic ecosystems. Cyanobacteria, or blue-green algae, naturally occur in aquatic environments but can proliferate rapidly under warm, nutrient-rich conditions. These blooms pose risks to human health, wildlife, aquatic species, local economies, and the overall ecological balance. The interplay between climate change and HABs is undeniable: rising temperatures and altered precipitation patterns foster conditions that exacerbate bloom occurrences.

Given these circumstances, it is crucial for lake managers and water utilities to adopt proactive measures. Early and consistent sampling efforts can detect cyanobacteria and akinetes, dormant spores that contribute to bloom formation. Additionally, reducing nutrient inputs, particularly phosphorus, into waterways is essential to prevent HABs. Princeton Hydro strongly recommends that lake managers, water utilities, and concerned community members closely monitor their lakes, reservoirs, and riverways to stay as proactive as possible in managing these valuable resources.

By raising awareness, fostering collaboration, and implementing effective strategies, we can work towards safeguarding the health and sustainability of our freshwater ecosystems. Together, we can address the challenges posed by HABs and protect the integrity of our water bodies. For more information about HABs, click here.

Dr. Fred Lubnow, Princeton Hydro’s Senior Technical Director, Ecological Services, is an expert in aquatic and watershed management, restoration ecology, community and ecosystem ecology, and the use of benthic macroinvertebrate and fish in-stream bioassessment protocols. Dr. Lubnow has managed hundreds of lake projects and provides technical expertise for a variety of lake and watershed restoration projects.

His experience in lake and reservoir restoration includes the design and implementation of dredging, aeration, chemical control of nuisance species, nutrient inactivation (i.e. alum) and biomanipulation. His experience in watershed restoration includes the design and implementation of structural Best Management Practices (BMPs), the development of Total Maximum Daily Load (TMDL) pollutant budgets, and the design, implementation and analysis of watershed-based monitoring programs.

• Climate Change
• Environmental Action
• Green Infrastructure
• Lake and Pond Management
• Stormwater Management