In Trouble on the St. Johns River, the Johnson kids Joey, Bobby and Katy are up to their adventurous ways again. But this time, instead of exploring history, they're making it! Joey and Bobby start their summer vacation by setting out for their favorite fishing pond, but end up leading a crusade to clean up the environment instead.Finding the pond covered with green muck and dead fish, the brothers decide to do something about it. That leads to a close encounter with a manatee, a visit to a center that rehabilitates injured sea turtles, and a boat tour on the St. Johns River. What they learn through these experiences inspires them to create The Greenies and chart a course of action that captures the attention of many, including a local TV station. By the end of the story, Joey, who thought there was nothing kids could do to make a difference, realizes that perhaps they are the very ones who can. Its a story of awakening that will inspire young readers to become more aware of their environment and give them some ideas on how to preserve it.