The Florida Fish and Wildlife Conservation Commission shared photos of the dolphin and the plastic hose on its Facebook page, along with a message.
"Your actions can make a difference - secure and properly dispose of trash, take part in coastal cleanups and share information on how to reduce marine debris with others," the post said.
The seven-foot-long male dolphin was recovered by a team of biologists from Fort Myers Beach in early May.
"During the necropsy, they found a 24-inch hose in the esophagus and forestomach of the animal," the FWC post read. "This is the second stranded dolphin in one month's time from this region that had ingested plastic - reminding us again to look closely at our habits."
Samples collected during necropsy will be sent for analysis to help determine the dolphin's exact cause of death, said FWC.