The bottlenose dolphin was called Honey and was left in a small pool at the Marine Park Aquarium, east of Tokyo, along with 46 penguins and hundreds of fish and reptiles.
One employee was tasked with feeding the remaining animals since the park was abandoned in 2018, however they were all largely alone.
The Dolphin Project made attempts to rescue Honey, however they weren’t able to get a deal in place in time.
A statement on their website states: “In late February of this year, we reached out to our Japanese colleagues once again in attempts to purchase Honey in order that she could be retired in peace and dignity.
“These conversations ended in early March when it became apparent Honey was unlikely to survive.
“Later that month on 29 March, Honey died in her tank.”
A video produced by the company shows the plight of Honey, who was forced to live out its final days in a tiny tank with virtually no stimulation or interaction with anyone or anything.
Sadly, it seems like this isn’t an isolated incident.
The Dolphin Project has been investigating multiple reports of animals being abandoned and left to die for myriad of reasons.
The statement continues: “Dolphin Project has encountered dolphins in the United States, South Korea, Haiti, Indonesia, Guatemala, Nicaragua, Colombia and Brazil whom were all in similar situations as Honey.
“In many instances, we were able to successfully rehabilitate and re-release these mammals.
“Honey’s plight attracted worldwide attention, and sparked a huge movement from within Japan. While tragically, she wasn’t able to escape the man-made enclosure she suffered in, Honey will remain the face of dolphin captivity for many years to come.”
Honey was reportedly grabbed during one of Japan’s controversial Taiji dive hunts in 2005.
Animals captured during those hunts are then sold off to live in captivity.
Inubosaki Marine Park Aquarium struggled financially after a downturn in visitors following the 2011 earthquake and tsunami. Despite the park finding a buyer last year, it was unable to get people to go and see the animals.
PETA’s director Elisa Allen said in a statement: “Because of human callousness, Honey found the only way out of the miserable tank she was imprisoned in and is finally at peace after years of suffering.
“From the moment she was caught in a net and dragged from her family and her ocean home, she languished alone in a cramped, filthy pool – where all she could do was swim in endless circles.
“While her death in a concrete cell marks the end of her wretched existence, PETA hopes it also marks the beginning of a new era for animals held prisoner at marine abusement parks.
“We all know enough about other living, feeling beings now that we can no longer justify depriving intelligent, self-aware animals of a meaningful life for human amusement.
“We must work to move captive marine animals to seaside sanctuaries – where they can enjoy some semblance of the natural life they’ve been denied for so long.”