Red tide is caused by the organism Karenia brevis, which is found naturally in the Gulf of Mexico at background levels. But concentrations can become deadly for marine wildlife when levels get too high, as they did during a particularly strong red tide that lasted from the fall of 2017 until the spring of 2019. The summer of 2018 was the worst, with dead and decomposing fish, birds and turtles piled up along local beaches. And while conditions are nowhere near as potent as they were three years ago, the threat is always there. “I think the conditions are ripening with nutrients along the coastal waters, and that can contribute to red tide blooms becoming more frequent, severer or longer-lasting,” said Jennifer Hecker, with the Coastal and Heartland National Estuary Partnership in Charlotte County. “I think it’s possible we will see more in the coming months, given those things.”