Swimmers are at a moderate risk for health problems in Lake Hopatcong's Crescent Cove, officials said.
Last month, a blue "watch" advisory -- which did not require the beaches to close -- were in effect at the beach areas of Lake Forest Yacht Club in Jefferson and Mount Arlington Beach.
Aerial surveillance by the state Department of Environmental Protection’s Division of Water Monitoring and Standards located cyanobacteria blooms in large parts of the lake.
Though not technically considered algae, the toxic blooms grow through photosynthesis and have a bright green appearance, the report says. They typically have a consistency resembling spilled paint or a thick coating.
The cause of the blooms could be connected to the mixture of heavy rain bringing nutrient-rich stormwater into the lake as well as the warm summer temperatures, according to the report.
Residents are warned to avoid contact with the water in the areas the bacteria was found. Fishing is permitted, but the fish should not be eaten, officials said.
The bacteria levels will continue to be monitored until levels are deemed safe for recreational contact.
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