The Florida Department of Health issuing a blue-green algae alert for the Coral Gables canal-East Side. It comes thanks to too many toxins in the water. Nova Southeastern University's Dr. Jose Lopez says heed all the warnings don't swim in the water and do not let your pets drink from it. Blue-green algae are bacteria common in freshwater usually when high temperatures and storms deliver nutrients into waterways through storm water runoff. That leads to water discoloration and odors harmful to people and animals. Blooms can occur year round, but are most common in summer and fall.