The DEP has received more than 30 reports of HABs on Lake Hopatcong since June 17, including reports of people experiencing mild skin rashes after coming in contact with lake water.
As a precaution, the DEP is recommending that local health authorities close all public swimming beaches along the lake due to the widespread nature of the bloom.
Based on the widespread nature of the HAB, the recreational advisory may be in place for weeks, if not longer.
The DEP will monitor cyanobacteria levels until the lake is determined to be safe for recreational contact.
Straddled by Sussex and Morris counties, Lake Hopatcong is New Jersey's largest lake and is a popular tourist and vacation destination. The DEP is working through the Lake Hopatcong Commission to notify municipal governments and local health agencies of the advisory.
The rapid spread of the bloom may be the result of heavy rainfall carrying nutrient-laden stormwater into the lake, followed by periods of warm weather, officials said.
Often referred to as blue-green algae, cyanobacteria are not true algae but are capable of excessive growth through photosynthesis.
Cyanobacteria blooms are usually a bright green, but can also appear as spilled paint, "pea soup," or as having a thick coating or "mat" on the surface. These blooms can often be confused for typical algae blooms.
Exposure can cause a range of health effects, including rashes, allergy-like reactions, flu-like symptoms, gastroenteritis, respiratory irritation, skin rashes and eye irritation.
Cyanobacteria are naturally present in lakes and streams in low numbers. Under suitable environmental conditions - sunlight, high nutrients, warm temperatures and calm water - dense cyanobacterial blooms can form.
In recent years, the DEP and the New Jersey Department of Health have been enhancing Harmful Algal Bloom surveillance and response efforts across the state.
In 2017, the DEP launched a campaign to educate the public about these blooms and provide resources on how to report them to the DEP. The "Avoid It and Report It" campaign advises the public to take the following steps when a suspicious bloom is observed:
Avoid contact with water in the vicinity of the bloom, especially in areas where the bloom is dense and forms scum;
- Do not drink or consume the water;
- Do not eat fish from the waterbody;
- Keep pets and livestock away from the water;
- Do not allow animals to drink the water, eat dried algae, or groom themselves after coming into contact with the water;
- People, pets and livestock that come into contact with a bloom should rinse off with fresh water as soon as possible;
- *eek medical attention or a veterinarian if a person or animal is experiencing adverse health effects after exposure to a bloom;
- Report a suspected HAB by calling the DEP Hotline at 1-877-WARNDEP (877-927-6337) send a mobile alert through the WARN NJDEP mobile app (available via iTunes, Google Play or Windows Phone) or report via the DEP's HAB website at www.state.nj.us/dep/wms/HABS.html
For questions regarding the freshwater harmful algal bloom strategy, call DEP's Bureau of Freshwater and Biological Monitoring at (609) 292-0427 or email njcyanohabs@dep.nj.gov
Click here to follow Daily Voice Parsippany-Troy Hills and receive free news updates.