For multiple summers in a row, several water-adjacent parts of Florida have been overrun by an unusual, invader. No, not tourists. Not snowbirds. Noxious, harmful, algal blooms.

And, though it’s barely spring, North Florida has already seen the first signs of the unwelcome invader. As WJCT recently reported, algal blooms have popped up in parts of the St. Johns River in the Welaka, Satsuma and Palatka areas of Florida.

“In some cases it’s extremely thick and there are reports of it crossing the entire river in the Palatka area,” Lisa Rinaman, the St. Johns Riverkeeper, told WJCT.

The algae can be highly toxic and harmful to the health of wildlife and humans, alike.

According to Rinaman, the algal blooms are caused by nutrient pollution, which flows into the river from septic tanks and fertilizer.

You can do your part to help keep North Florida from having a bummer summer, by reporting Algal blooms to the Florida Department of Environmental Protection.

Read the full story on WJCT here.