The dugong, a gentle marine mammal, has been declared officially extinct in China, a study finds.
In findings published by the Zoological Society of London in the journal Royal Society open Scienceconservation scientists found “strong evidence” that the country’s mammals are extinct.
Scientists made the discovery after surveys of fishing communities across China. Data from previous years was also used to compare the past presence of dugongs in the country.
Sometimes referred to as “sea cows”, due to their seagrass diet, dugong can be found in coastal waters in the Indian and Western Pacific Oceans. The species is listed as vulnerable by the International Union for Conservation of Nature (IUCN).
They have been protected in China since 1988 and have lived there for hundreds of years.
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According to the study, scientists would “welcome any possible future evidence that dugongs might survive in China,” but the study authors said it “provides important evidence of the likely regional loss of a charismatic marine megafaunal species.”
Surveys found no evidence of dugong in Chinese waters. Before noting them as extinct, scientists considered the possibility that the species moved north along the coastline “in response to human activity or climate change.” However, they concluded that this was unlikely, as there is a lack of seagrass beds north of the dugong’s usual habitat.
The study also notes that “no other dugong sightings or strandings have been reported” from that area.
The study authors also recommend changing the status of the species to critically endangered (possibly extinct).
Samuel Turvey professor at ZSL’s Institute of Zoology and co-author of the study told News week that their extinction in China could lead to “a major negative impact on the health of seagrass systems”.
“However, the disappearance of dugongs from the northern South China Sea has been largely caused by the disappearance of the seagrass beds themselves — tragically, the entire ecosystem has been gradually destroyed by human activities,” he said.
Turvey said dugongs are a “keystone species,” meaning they “can help shape the structure of their wider ecosystem.”
“Our study demonstrates the utility of using local ecological knowledge to understand the status of endangered biodiversity and to reconstruct extinction dynamics – and we encourage other conservation studies to work with local communities to assess environmental requirements and threats to other rare species. species,” Turvey said. “Tragically, our findings also demonstrate the rapid disappearance of dugongs from Chinese marine ecosystems — highlighting the critical importance of developing effective conservation measures before it’s too late.”
The decline of the dugongs in China was largely due to habitat loss. Turvey said this is due to factors such as coastal development and water pollution.
Seagrass beds in particular are very vulnerable to ‘eutrophication’ – algal blooms due to anthropogenic increases in nutrients in the water (e.g. from sewage), which reduces the ability of light to penetrate seawater and thus prevents seagrass photosynthesis .