The Florida Department of Health in St. Johns County (DOH-St. Johns) cautions the public of the presence of blue-green algae in the St. Johns River- Shands Bridge on October 14, 2025. Water sample testing is underway. Blue-green algae have the potential to produce toxins. Since environmental conditions can change at any time, it is important to exercise caution, even if presence of toxins has not yet been confirmed.