The gentle giants of the sea have not been seen in China for over 14 years, with scientists citing habitat destruction and hunting as key factors in their decline.
Photo credit Patrick Louisy
The dugong is now functionally extinct in China, according to scientists,
with no sightings of the giant, gentle-natured marine mammal recorded since
2008.
Alongside human-induced habitat destruction, fishing, ship strikes, and
hunting are key threats that have resulted in the dugong’s decline,
according to the new study by the Zoological Society of London (ZSL) and the
Chinese Academy of Sciences.
“The likely disappearance of the dugong in China is a devastating loss.
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,” said Professor
Samuel Turvey of ZSL’s Institute of Zoology who co-authored the research
published in the Royal Society Open Science journal.
The dugong frequented China's southern waters for centuries, but from 1975
onwards, their population began to "decrease rapidly." In 1988 the marine
mammal was classified as a grade one national key protected animal by the
Chinese state council, which technically affords it the highest level of
protection.
Dugongs are dependent upon seagrass, a specific marine habitat that is being
rapidly degraded by human impacts, from coastal development to water
pollution. Despite seagrass restoration and recovery efforts a key
conservation priority in China, the continued habitat destruction caused a
"rapid population collapse", researchers believe.
“In 2007, we tragically documented the likely extinction of China’s unique
Yangtze River dolphin. Sadly, 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 Turvey.
Photo credit Patrick Louisy
The researchers conducted extensive interview surveys in local fishing
communities across four southern maritime provinces in China. To build
further evidence of potential dugong presence in those areas, they also
reviewed historical data covering past dugong distribution in China.
"Through interview surveys, we gathered valuable information that was
previously not available for making evidence-based evaluations of the status
of dugongs in the region,” said Dr Heidi Ma, Postdoctoral Researcher at
ZSL’s Institute of Zoology and also an author of the study. “This not only
demonstrates the usefulness of ecological knowledge for understanding
species’ status, but also helps us engage local communities and to
investigate possible drivers of wildlife decline and potential solutions for
mitigation."
The authors say that they would ‘welcome any possible future evidence’ that
dugongs might still persist in China. However, this exhaustive survey found
no recent evidence of dugong survival across their known distribution in
mainland Chinese waters. The authors now recommend that the species’
regional status should be reassessed as Critically Endangered (Possibly
Extinct).
While the dugong still exists in other parts of the world, including
coastal waters off tropical and sub-tropical countries from East Africa to
Vanuatu, and as far north as the southwestern islands of Japan, they are
globally threatened due to human activities and listed as ‘Vulnerable’ by
the International Union for Conservation of Nature (IUCN).
According to the UN Environment Programme, up to 7 percent of seagrass
habitats are lost each year. The majority are destroyed by unrestricted
fishing, climate catastrophe, and pollution from the agricultural and
industrial sectors.
“One by one we are witnessing a vanishing act of key species across the
planet. The functional extinction of the dugong in China serves as the
latest wake-up call that industrial fishing, hunting, and habitat loss need
our urgent attention and action,” Seaspiracy director Ali Tabrizi told
Plant-Based News.