Each and every morning, and even on his recent days off, Beltzville State Park Manager Cody Miller visits the beach.

He’s not going to swim, rather, he’s looking for signs of algae.

Miller’s visual inspections supplement an annual Department of Conservation and Natural Resources water sampling program that began this year on June 10.

And while Miller hasn’t seen the greens and blues of algae at the beach area, water samples collected from some parts of the lake have detected harmful algae blooms (HAB).

On Friday, the park issued an advisory for HABs.

“The whole lake isn’t impacted in the same way,” Miller noted. “The beach has been clear and testing has indicated that it is in safe parameters for swimming as well.”

Under the advisory, swimmers are encouraged to wash after being in the water. Visitors — and their pets — are asked to avoid contact with discolored water or film.

“We’ve been monitoring it almost all season,” Miller said, noting that sampling will continue.

Kylie Wirebach, a DCNR aquatic biologist who oversees monitoring programs, said the algae occurs naturally.

“Despite the name, HABs are actually caused by an overabundance of cyanobacteria. There are many species of cyanobacteria and they are present in nearly every body of water in the world,” she said.

When they become overabundant, they can rapidly overproduce and release cyanotoxins, which are the chemicals that make HABs dangerous.

“Winds, sun exposure, tributaries and water depth can have large impacts on the movement and prevalence of cyanobacteria,” Wirebach said. “We often observe them in shallow coves, while large areas of deep, open water stay relatively HAB-free.”

Miller said smaller bodies of water could be treated for HABs. Treating the 7-mile-long Beltzville Lake, which holds 14 billion gallons of water, would be next to impossible.

“HABs are as natural and seasonal as the migration of birds or the changing of leaves in the fall, however they are harder to predict and anticipate especially in large lakes,” Wirebach explained. “Some will dissipate naturally after a rainstorm while others persist for months. Patience and consistent monitoring are key.”

Miller noted that DCNR monitors all of its swimming lakes for algae toxins. The agency also checks for E. coli bacteria weekly.

Signs are posted to urge visitors to avoid contact with the algae.

As long as results continue showing safe ranges, the beach will remain open until the end of Labor Day weekend.

Those who decide to stop by the park are advised to:

• Wash their hands after contact with untreated water.

• Shower or bathe immediately after participating in water-based recreation activities.

• Avoid swallowing and inhaling untreated water during recreational activities.

• Avoid contact with water that has foam, film or discoloration.

• Seek and follow any water body advisories or closures.