The dugong has been declared extinct in China in what has been described as a "wake-up call" for international efforts to safeguard the gentle marine mammal.
Research by the Zoological Society of London and the Chinese Academy of Sciences said the impact of fishing, ship strikes and habitat loss fuelled by human activity had prompted a decline in numbers, which had been dwindling since the 1970s.
The creature, found in more than 30 countries, including the UAE, is affectionately known as the 'sea cow' due to its habit of grazing on ocean seagrass.
It is typically found in coastal waters and is listed as vulnerable by the International Union for Conservation of Nature.
The study found there were no records of the dugong's presence in China since 2008.
“Our new study shows strong evidence of the regional loss of another charismatic aquatic mammal species in China – sadly, once again driven by unsustainable human activity,” said Professor Samuel Turvey of ZSL's Institute of Zoology, one of the authors of the report, published in the Royal Society Open Science journal.
"Their absence will not only have a knock-on effect on ecosystem function, but also serves as a wake-up call - a sobering reminder that extinctions can occur before effective conservation actions are developed."
Authors of the study said they would welcome any evidence that dugongs were still in China, however their research shows no recent evidence of dugong survival across their known homes in mainland Chinese waters.
Dugongs are threatened by sea grass habitat loss and degradation, often caused by coastal development or water pollution.
If starved of enough sea grass to eat, the dugong will not breed normally.
They are also at risk of being entangled in fishing nets.
UAE works to protect beloved mammal
Abu Dhabi has an estimated 3,000 dugongs, the second-highest population in the world after Australia. Most are found in the waters of Marawah Biosphere Marine Reserve, about 160 kilometres west of the capital.
A ban on fishing nets introduced in the UAE in 2019 halved the dugong mortality rate, a 2020 study by the Environment Agency Abu Dhabi revealed.
The agency found 10 dugongs died in the capital during the 2019-2020 winter season, compared with 23 in the same period last year.
It attributed the sharp drop in deaths to a December 2018 ban on surface fishing nets in the emirate.
The mammals cannot breathe underwater so must surface for air every few minutes. Consequently, they die quickly if they become entangled in nets, which are easily lost at sea.
Prior to the regulation, the dugong death rate rose annually and last season was the highest on record. Most were caused by drowning after they became trapped in nets.
“In 2018, the number of the deaths crossed a red line, so we said, ‘it stops here’,” said Ahmed Al Hashmi, acting executive director of terrestrial and marine biodiversity for the agency.
In February 2020, the Secretariat of the Convention on Migratory Species (CMS) and Environment Agency Abu Dhabi extended their decade long partnership for the conservation of species like the dugong, marine turtles and many migratory birds in the region.
Dugongs have been protected under UAE law since 1999.