Toxic ‘green-blue’ algae has spread eastward along the Gulf Coast of Mississippi, forcing the state to close the totality of its mainland beaches. The Mississippi Department of Environmental Quality determined that the algae bloom posed a significant risk to people and animals in and near the waterline and made the choice to close the majority of mainland beaches at the end of June. The final two were closed on Sunday.

Green-blue algae is the common name for cyanobacterium that is known to cause rashes, vomiting, and diarrhea. Severe cases of toxicity have reportedly caused liver failure. The algae is also harmful to freshwater and brackish ecosystems.