As Underwater World Singapore (UWS) prepares to take its final curtain call, the next generation of ever-larger marine parks is set to intensify the controversy over keeping marine mammals in captivity.
The Marine Life Park and Dolphin Island at Resorts World Sentosa (RWS), which opened in 2012 and 2013, have been beset by animal deaths and besieged by calls from animal rights groups for the release of more than 20 Indo-Pacific bottlenose dolphins caught in the Solomon Islands.
Despite the furore, US non-profit environmental organisation Conservation International signed a five-year partnership with RWS in 2014 to work on conservation and public education projects in Singapore and the region, including a project to better understand and protect manta rays in the wild.
The new home of some of UWS' dolphins, fur seals and otters has also been a magnet for controversy.
Chimelong Ocean Kingdom in Zhuhai, China, to which those animals have been transferred, was launched in 2014 as one of the world's largest marine life parks.
UWS said in a statement that Chimelong is one of the finest facilities in the world, with expertise in caring for marine mammals and an active conservation programme.
But recent reports have voiced concern about the welfare of marine mammals at Chimelong, from polar bears pacing back and forth in their enclosure in a distressed manner to beluga whales nodding in time with loud music.
Ms Anbarasi Boopal, deputy chief executive of the Animal Concerns Research and Education Society (Acres), said UWS should have explored options for rehabilitating its animals to the wild instead of sending them to another marine park, and called for clarifications on how the dolphins will be used at Chimelong.
The marine park is part of a booming industry that reports say is taking a toll on wild populations of iconic species and keeping many captured specimens in unfavourable conditions.
Ms Boopal said capturing marine mammals from the wild for display does not have any conservation value as it depletes their already threatened natural populations.
Mr Stephen Beng, chairman of the marine conservation group of the Nature Society (Singapore), said: "Marine species face widespread and under-policed hunting and fishing."