Dugong feared extinct in China due to environmental degradation

The extinction of the dugong in China has raised concern about its possible disappearance from the rest of the planet, Science Editor Deborah Cohen reports

Researchers fear the dugong is now extinct in China, due to environmental degradation.

The sea creature, a species of marine mammal similar to the American manatee, provided the inspiration for mythical mermaids.

There have only been three reported sightings of dugongs across China's provincial waters within the past five years, according to new research published in the Royal Society Open Science journal.

No confirmed sightings of the species in the wild have been recorded since 2008.

Dugongs can grow to about 3.4 metres (11 feet) in length, and are thought to have inspired mermaid mythology as sailors spotted the paddle-tailed creatures from afar.

Researchers, say the herbivorous dugong's natural shoreline habitats of shallow waters and seagrass beds have left them vulnerable to overfishing and shipping accidents.

The UN Environment Programme estimates that 7% of seagrass habitat is being lost worldwide each year, mainly due to industrial pollution, coastal development, unregulated fishing and boating activities, and climate change.

The species' late-maturing and low reproductive characteristics may also be a contributing factor to their extinction in the region, researchers say.

Dugongs exist elsewhere in the world, but are facing similar threats.

The marine mammal was listed as globally vulnerable by the International Union for Conservation of Nature (IUCN) and as a Grade 1 National Key Protected Animal since 1988.

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A dearth of recent studies about dugongs' survival in recent decades led researchers to turn to locals in China for help.

They interviewed 788 people living in the marine communities around known dugong habitats, to determine when locals last saw the species.

Residents reported not seeing a dugong for an average of around 23 years. Only three people said they had seen one in the past five years.

Researchers say the dugong population mostly declined during the twentieth century, after the mammals were documented in Chinese waters for several hundred years.

They say the extinction of the marine mammal "reflects the latest stage in the progressive ecological deterioration of marine ecosystems in Chinese waters".

Those marine ecosystems host approximately one-third of the world's marine mammal species.

"This rapid documented population collapse also serves as a sobering reminder that local extinction can happen within a very short time, especially for long-lived, late-maturing species with low reproductive rates," the report continued.

"Deliberate hunting combined with the degradation of seagrass beds and accidental entanglement probably together contributed to the rapid collapse of China's dugong population."

Dugongs and manatees, with their paddle-like tails, are believed to have inspired mermaid legends.

In mermaid mythology, beautiful half-woman, half-sea creatures lure shipwrecked sailors to their watery deaths, like the sirens of Greek myths .

'Mermaid' sightings by sailors in centuries gone by are thought to really have been sightings of dugongs or manatees, also known as 'sea cows'.

In his first 15th-century voyage to the Americas, explorer Christopher Columbus reported seeing 'three mermaids' that were described as being not as beautiful as expected - instead having faces with rather 'masculine traits.'

According to the National Geographic, 'mermaid' skeletons exhibited in Europe's medieval creature sideshows were later found by scientific researchers to be dugong remains.