By: Richard L. Smith
A Harmful Algal Bloom (HAB) Advisory has been issued for Mountain Lake in Liberty Township, Warren County, following the detection of potentially hazardous cyanobacteria in the water. 
The announcement was made on Friday, according to information released by the New Jersey Department of Environmental Protection (NJDEP) and the Division of Fish and Wildlife.
Officials are urging the public to refrain from consuming any fish caught from Mountain Lake until further notice, as the bloom could pose health risks to both people and pets.
HABs are caused by the rapid growth of cyanobacteria, commonly known as blue-green algae.
According to information from the U.S. Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC), these blooms typically form in warm, nutrient-rich, and slow-moving water—often a result of excess phosphorus and nitrogen from stormwater runoff, fertilizers, or septic system leaks.
While not all algal blooms produce toxins, the harmful types can lead to a range of health issues.
Contact with or ingestion of contaminated water or fish can cause skin rashes, respiratory irritation, gastrointestinal illness, and, in severe cases, liver or neurological damage.
The NJDEP is actively monitoring the situation and will provide updates on its HAB Dashboard, where the public can find real-time data, safety alerts, and additional guidance.
Residents are encouraged to avoid contact with the water during the advisory and to report any signs of algal blooms—such as green scum, discoloration, or foul odors—to state environmental authorities for immediate investigation.