Ohio Department of Health Harmful Algae Blooms harmful algal blooms Harmful Algae Blooms Harmful Algal Bloom – Ohio Dept. Health Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms Harmful Algae Blooms as described by the World Health Organization (WHO) Ohio Department of Health as described by the World Health Organization (WHO)