In the waters off Florida and Louisiana, bottlenose dolphins are exhaling more than just spent air. They are breathing out microplastic particles — tiny bits of plastic pollution that have become a pervasive threat to marine life. Researchers from the College of Charleston in South Carolina note this is the first time these particles have been detected in dolphin breath. The discovery suggests that inhalation, long overlooked, might be a significant way that dolphins — and potentially other marine animals — are exposed to microplastics. “We are concerned by what we are seeing because dolphins …