ROXBURY, NJ - Interior portions of Lake Hopatcong might seem clear of the "harmful algal bloom" (HAB) that's impacted the lake, but potentially dangerous levels of cyanobacteria are lurking “below the surface” of even those areas, warned the state today.

In an update on the HAB taking place at the state’s largest lake, the state Department of Environmental Protection (DEP) said its swimming and recreational-use advisory remains in effect.

“DEP sampling indicates that cell counts for cyanobacteria causing the bloom remain above the New Jersey Health Advisory Guidance levels,” the DEP said. “Consequently, the DEP advises continued closure of public swimming beaches and recommends the public not use the lake for recreational watersports such as personal watercraft use, water-skiing, paddle-boarding, canoeing or kayaking.”

Sign Up for Roxbury Newsletter
Our newsletter delivers the local news that you can trust.

The state said it has continued to sample water from the lake and conduct aerial surveillance using sophisticated equipment. It said the situation might be slightly better than it was last week, but the lake water continues to be unsafe.

“While interior, open portions of the lake appeared to be clearer than last week, water sampling showed continued elevated levels of cyanobacteria, with the highest levels below the surface,” the DEP warned.

The state offered this advice:

  • 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

  • Seek medical attention or a veterinarian if a person or animal is experiencing adverse health effects after exposure to a bloom

Shrugging it Off

Despite the state’s warnings, some lake lovers are scoffing. On social media, these individuals are referring to the DEP’s statements - and media reports about them - as “fake news.” Some are posting videos of themselves, or their acquaintances, water skiing or otherwise ignoring the DEP’s advice.

Nevertheless, the DEP insists the cyanobacteria found in HABs are not something worth challenging.

“Exposure to a harmful algal bloom can cause a range of health effects, including rashes, allergy-like reactions, flu-like symptoms, gastroenteritis, respiratory irritation and eye irritation,” it said. “Exposure to a harmful algal bloom that is actively producing cyanotoxins may result in more serious health effects, including liver toxicity and neurological effects. Harmful algal blooms may begin producing cyanotoxins at any time.”

The state said the bacteria involved in an HAB are not true algae, and naturally occur in lakes and streams in low numbers. However, “under suitable environmental conditions – sunlight, high nutrients, warm temperatures and calm water – dense cyanobacterial blooms can form,” said the DEP.

It said HABs, also known as blue-green algae. 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.

State Assemblyman Anthony Bucco, who represents Roxbury, said the HAB will be the subect of a public discussion at the Lake Hopatcong Commission (LHC) meeting to be held July 8 at 7 p.m. at Hopatcong High School. He said DEP Comnissioner Catherine McCabe  plans to attend herself and tour the lake prior to the meeting.

The state is asking the public to 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

Click here to sign-up for our free, daily e-newsletter.

Please “like” and “follow” our Facebook Page and Twitter feed.

Want to help support local journalism and promote your business to thousands of community-minded readers? Become a TAPinto Roxbury advertiser! Call 862-259-2448 or click here.