Ocean Park’s six-year-old dolphin, Cleo, died on Sunday of unknown health problems that lasted more than a week, the park announced. The female Indo-Pacific bottlenose dolphin had no health problems before the illness, but was placed under veterinary care after she started to display a reduced appetite and high body temperature on April 18, a spokeswoman said. Despite attempts to save her, the dolphin’s health worsened on Friday and she died on Sunday. An autopsy will be conducted to determine the exact cause of death. In the absence of Cleo, the park now has 22 Indo-Pacific bottlenose dolphins, or Tursiops aduncus. Cleo was born at Ocean Park in August 2012 and grew up in the park’s Marine Mammal Breeding and Research Centre, a facility known for its educational programmes for the public. ‘Empty the tanks’: Hong Kong’s Ocean Park at centre of activists’ battle to stop dolphin captivity Cleo had not been performing at the park’s Ocean Theatre with the other dolphins. Michael Boos, the executive director of zoological operations and conservation, said the park’s animal care team had provided all the veterinary treatment possible, but to no avail. “As one of our key animal ambassadors, Cleo has helped to raise public awareness about dolphin and marine conservation, and she will be dearly missed,” Boos said. The government’s Agriculture, Fisheries and Conservation Department was notified of Cleo’s death. In the financial year 2017-2018, Ocean Park was housing 7,807 individual animals, including 66 marine mammals, 55 land mammals, 494 birds and more than 7,000 fish. In that year, one marine mammal died at the park: a two-month old harbour seal who had a liver disease. The total number of animal deaths was 712 due to various causes. There were two marine mammal deaths the previous year: two California sea lions who died of old age.