New jersey has been lucky with fresh water algae blooms... For now — Water lily pads duckweed and green algae on a lake surface

By Jason E. Adolf, PhD

Environmentalists from around the state have rightly voiced their alarm over the spike in harmful algal blooms (HAB) plaguing freshwater bodies like Lake Hopatcong and Greenwood Lake this summer and called for more aggressive watershed management-based solutions. My 22 years of experience as a scientist working with HABs has given me a perspective on the urgency of what is happening and why solutions need to be enacted now. New Jersey is actually lucky right at the moment ― cyanotoxin levels remain low even though the lakes are filled with high levels of HAB organisms. However, research into the factors that amplify toxin levels in blooms like these suggests that it is only a matter of time before our luck runs out.

The expansion of freshwater cyanobacteria (often called blue-green algae) blooms has been noted for years among researchers. While many recent media reports have focused on the link between nutrients, climate and HAB formation, none have clearly articulated the threat posed by the potent toxins these HABs can produce if and when they start to produce them in excess. The latest measurements by the New Jersey Department of Environmental Protection (NJDEP) show that HABs are occurring without high toxin levels. However, this can change and it is worth noting that the public health crisis presented by a lake full of toxin-producing HABs is far greater than what we are currently seeing, as evidenced by the highly toxic HABs that occurred in Florida’s Lake Okeechobee in the summer of 2018.

The microorganisms that cause these HABs can, under certain conditions, start producing high levels of potent toxins. Think of the HABs as collections of cells – not just different species but also different “strains,” or genetic variants, of the same species. Some strains make cyanotoxins, and others don’t.

For instance, the species Microcytis can produce the toxin microcystin. A lake full of the species Microcystis will include some strains that do not make cyanotoxin and some strains that do. Of course, bigger blooms potentially make more cyanotoxin, but an increase in the ratio of toxic to non-toxic strains can also change overall toxicity. When a lake is dominated by non-toxic strains of Microcystis, then overall cyanotoxin levels (microcystin) are low. When toxic strains dominate, then overall cyanotoxin levels are high.

To date, according to the July 25 NJDEP Lake Hopatcong sampling update, cyanotoxin levels remain below the 3 parts per billion (ppb) New Jersey health advisory level, even though cyanobacterial cell levels are high. By comparison, microcystin cyanotoxin levels in the 2018 Florida blooms exceeded 100 ppb and many people were hospitalized following contact.

Thus, the attention and crisis surrounding New Jersey’s 2019 lake HABs, while very much warranted, is due to the presence of cells without significant levels of cyanotoxin present. What if we had to deal with high cell and cyanotoxin levels in places like Lake Hopatcong and Spruce Run Reservoir?

What turns a less-toxic HAB into a highly toxic HAB? A few highlights from contemporary research conclude that excess nitrogen loading (even in the face of phosphorus controls) appears to favor toxic strains over non-toxic strains of Microcystis. Other experiments in North American lakes found that elevated water temperature, in combination with elevated nutrients, favors accumulation of toxic Microcystis strains over non-toxic strains. Elevated temperature and CO₂ levels are likely to favor accumulations of cyanobacteria in lakes over other types of algae. This area of research is continuing and needs investment in New Jersey because understanding the specific conditions that turn our HABs into highly toxic events will inform management and predictive modelling of these events. This research, along with informed citizens anxious to play a role in the science associated with monitoring and prediction, will help us get ahead of this problem instead of repeatedly reacting to events after they occur ”out of nowhere.”

The impacts of humans, including excess nutrient loading to lakes, elevated CO₂ levels and rising water temperatures due to climate change, will not only ensure the reoccurrence of these blooms but stack the odds in favor of them becoming toxic and a far more menacing public health threat than what we currently see in New Jersey. Research into these linkages must play an important role in directing actions for solutions.

Jason Adolf is an endowed associate professor of marine science with Monmouth University’s Biology Department and Urban Coast Institute. He runs the Phytoplankton and Harmful Algal Bloom research lab (PHABLab) at Monmouth University, where undergraduate students learn phytoplankton research including HABs in various New Jersey environments. Instagram: monmouth_phab_lab.

Phil Stilton Latest posts

Phil Stilton is the Editor and Publisher of Shore News Network, an independent digital newsroom providing original reporting on New Jersey, national news, government, public policy, public safety, courts, and community affairs.

As founder of the publication, Stilton leads editorial strategy, investigative reporting, and daily newsroom operations while overseeing coverage that reaches millions of readers annually.

With extensive experience covering municipal government, county government, state legislatures, elections, law enforcement, emergency management, and public records, Stilton specializes in translating complex government actions into clear, factual reporting. His work frequently relies on primary source documents, including court filings, legislation, public meeting records, election finance disclosures, government databases, police reports, and Freedom of Information and Open Public Records Act (OPRA) requests. He has reported extensively on local government accountability, taxpayer spending, campaign finance, public corruption investigations, infrastructure, public safety, and the policies affecting New Jersey residents.

Under Stilton's editorial leadership, Shore News Network has grown into one of New Jersey's largest independent digital news organizations, publishing thousands of original news articles each year while providing breaking news coverage, investigative reporting, and analysis across state and local government. The publication's reporting is routinely sourced from official government agencies, public officials, court records, and firsthand documentation, with a commitment to transparency, attribution, corrections when warranted, and clearly distinguishing factual reporting from opinion.

Stilton's journalism follows established newsroom standards emphasizing accuracy, verification, fairness, and accountability. Every effort is made to verify information through official records and multiple reliable sources before publication. His reporting is intended to provide readers with timely, well-documented information that helps them understand the issues affecting their communities, while maintaining editorial independence from political parties, government agencies, advocacy organizations, and commercial interests.

Readers can submit story tips, corrections, public records, or media inquiries through the official Shore News Network website or its verified social media channels. Shore News Network welcomes corrections and updates when new information becomes available as part of its ongoing commitment to accurate and transparent journalism.