SeaWorld Orlando released into the wild Tuesday what may be the lone survivor of a puzzling dolphin die-off, Florida Today reports.

First spotted back in June by a kayaker, the male dolphin was found tangled in a thick bed of seagrass in the Merritt Island National Wildlife Refuge. When SeaWorld staff arrived on the site, they found an emaciated animal with signs of a severe sunburn.

"The top half of its body was out of the water," Teresa Mazza, a research assistant with Hubbs-SeaWorld Research Institute in Melbourne Beach, told the news outlet at the time.

Officials expressed feeling "cautiously optimistic" when, two days later, the dolphin was eating and in stable condition.

Over the course of the last five months, SeaWorld staff have slowly nursed the dolphin back to health with around-the-clock care that included chest x-rays and treatment for a respiratory disease.

Blood and other fluid samples taken from the animal during its stay may help to shed light on the culprit behind this year's dolphin die-off: In all, 74 dolphins living in the Indian River Lagoon have been killed for reasons that are not quite clear. Studies have suggested a range of possibilities, including an increased risk of choking among the lagoon's dolphins. It's also been noted that since 2009, algae blooms have plagued much of the lagoon, with resulting toxins potentially harming local marine life and their food chain.

Meanwhile, on the other side of the country, SeaWorld San Diego announced the arrival of a new calf Tuesday. The calf was born after a 12-month gestation period to a Pacific bottlenose dolphin known as Kolohe. Both are reportedly doing well with the calf's gender to be determined in coming weeks. The birth, the result of natural breeding, marks the 79th successful dolphin birth at SeaWorld San Diego.