Officials close all Mississippi beaches due to blue-green harmful algal bloom

"The algae can cause rashes, stomach cramps, nausea, diarrhea and vomiting."

All 21 of Mississippi's beaches have been shuttered for swimming due to the presence of toxic algae.

The Mississippi Department of Environmental Quality announced two additional closures on Sunday due to a blue-green harmful algal bloom, after previous closures were issued for the 19 other beaches along the state's Gulf Coast.

The two beaches that were shut down on Sunday are in Pascagoula, Mississippi, on the Alabama border.

The Mississippi Department of Environmental Quality is urging people and their pets to avoid water contact in the affected areas, such as swimming, wading or fishing, and to avoid eating anything taken from the waters "until further notice."

"The closure refer to water contact and does not prohibit use of the sand portion of a beach," the state agency said in a statement. "The algae can cause rashes, stomach cramps, nausea, diarrhea and vomiting."

Every U.S. coastal and Great Lakes state experiences harmful algal blooms, or HABs, which occur in fresh, salt and brackish water bodies when algae colonies "grow out of control and produce toxic or harmful effects on people, fish, shellfish, marine mammals and birds," according to the National Oceanic and Atmospheric Administration (NOAA).

Human illnesses caused by the blooms are rare, but can be debilitating or even fatal.

"I had a feeling it was going this way. Water always flows west to east," Pascagoula resident Bill Kenan told Biloxi ABC affiliate WLOX. “It just keeps going and going and going. I don’t know if it’s ever going to get better. I hope it does."

Climate change and increases in nutrient levels of bodies of water due to fertilizer run-off are potentially causing HABs to occur more often and in areas not previously affected, according to the NOAA.