Dolphinaris Arizona – a controversial dolphinarium in the desert near Scottsdale, Arizona, US, which opened in 2016 – has closed, following the death of its fourth dolphin in a little over two years.

Kai, a 22-year-old bottlenose, died at the facility on 31 January 2019, just one month after the death of Khloe, an 11-year-old that had suffered a chronic illness due to a parasite for six years. Following these deaths, the marine habitat was closed for evaluation by a panel of experts, including lab and water testing.

A statement from the company quoted in KTAR.com said it was optimistic that it would be able to reopen as a "new concept, not involving dolphins, and continue to carry out its mission in ocean conservation and education".

The four remaining dolphins at Dolphinaris Arizona are reported to have been transferred to the Coral World Ocean Park in the US Virgin Islands, where they will live at the newly-developed St Thomas Sea Sanctuary – a 69,000sq ft (21,000sq m) natural ocean habitat where they can be monitored by licensed vets and dolphin experts.

However, it seems that after acclimatising to their new home the four dolphins will be expected to come into contact with, and swim with, the public, as they did at Dolphinaris Ariziona. This has prompted renewed fears for their health, as has the location of their new home, which animal welfare organisation Dolphin Project has said is “vulnerable to extreme weather and frequent contamination with runoff”, in a report on Care2.com.