The Oregon Health Authority won’t be able to monitor toxic algae blooms in rivers and lakes as closely after a federal grant expired. Oregon state officials have used the grant for the past five years to post signs and educate the public about the dangers of algae blooms in the state’s rivers, lakes and reservoirs, Statesman Journal reported.

Every summer, toxic algae blooms prompt public health alerts across much of the northwest U.S. They often lead to authorities shutting down recreation sites where the blue-green algae thrive.

According to the Associated Press, when the federal Centers for Disease Control and Prevention grant to monitor algae blooms in Oregon was in place, health officials posted between 10 and 20 toxic warning signs across the state every year. But with the $150,000 grant no longer available to pay two employees, travel and materials for monitoring toxic algae blooms there, health officials will no longer be able to monitor water samples and educate the public, although the Oregon Health Authority will continue to issue warnings at some lakes.

"This gives us even more reason to tighten the knobs on nutrient inputs into these bloom-sensitive waters," Hans Paerl, a professor of marine and environmental sciences at the University of North Carolina at Chapel Hill, told the AP.

According to the Centers for Disease Control and Prevention, grants to monitor dangerous algae blooms, which scientists believe come from fertilizer pollution as well as climate change, went to nine states for five years to help build public awareness on harmful algae blooms. The grants focus on gathering data in order to monitor illness from harmful blooms. But there are gaps in the process.

"So many water bodies just aren't monitored, either because they are too small, no one is in charge or they are too remote," environmental toxicologist David Farrer told the Associated Press. "It's hard to tell if all the increase we saw was just increased awareness or there were actually more blooms going on."

Farrer told the Statesman Journal that educating the public about algae blooms is much like the campaign to inform residents of the dangers of poison oak. “You can’t post a sign by every stand,” he said. “The goal is to educate people.”

Blue-green algae, also called cyanobacteria, are one of the oldest life forms on the planet. They were responsible for creating Earth’s atmosphere billions of years ago when the algae began separating oxygen from our planet’s water.

But now, harmful algae blooms are on the rise worldwide.

“Cyanobacteria are basically the cockroaches of the aquatic world, they’re the uninvited guest that just won’t leave,” Timothy Otten, a postdoctoral scholar at Oregon State University, said in a press release about a new study on toxic algal blooms. “When one considers their evolutionary history and the fact that they’ve persisted even through ice ages and asteroid strikes, it’s not surprising they’re extremely difficult to remove once they’ve taken hold in a lake.”

He added. “For the most part, the best we can do is to try to minimize the conditions that favor their proliferation.”

According to Otten’s study, published Friday in the journal Science, nutrient enrichment and rising global temperatures are making some algal blooms in freshwater lakes and ponds more toxic. This creates more and more cyanobacteria, which can reproduce explosively under ideal conditions and are toxic to human and animal life. Researchers estimate that one-third of all lakes in the U.S. contain toxin-producing cyanobacteria.