Gerry Palmers Science 08.25.2022 00:Aug AM EDT

Study Finds Undersea Mammal Dugong ‘Functionally Extinct’ in Waters South of China

Scientists have declared the endearing undersea mammal dugong "functionally extinct in a part of the South China Sea.

In a study published in the Royal Society Open Science journal, the scientists blame hunting, the fishing industry, aquaculture, and destructive human activity for the degradation of the dugong's seagrass habitat that caused the animal to find it difficult to survive.

Inspiration for Mermaid Folklore, 'Pokemon' Character

Dugongs are the last remaining survivors of its scientific family, having the manatees as their closest relatives. They are thought to have been the inspiration for mermaid folklore, and a lovable Pokemon animated character "Dewgong" (although it was thought by Pokemon fans to be a seal).

This means these popular singular "sea cows" have one less region to swim around, the study authors said. By declaring dugongs as functionally extinct there, these researchers are declaring thst the species can no longer reproduce and maintain a long-term population in the area.

The research team, which is composed of scientists from the Chinese Academy of Science, England's Zoological Society of London, and Aristotle University in Greece, reported tha dugongs in the coastal waters southern China have decreased in numer over half a century. And, they emphasized that there have not been any documented records of dugongs in the area since 2008, no "verified field observations" or sightings of the mammal after 2000. It's "the first reported functional extinction of a large vertebrate in Chinese marine waters," they added.

How Scientists Arrived at Dreaded Conclusion

To come to this dreaded conclusion, the scientists reviewed historic records and collaborated with a group of volunteers and surveyed 788 local fishermen. The survey showed that only five percent of the respondents reported ever having seen a dugong in the wild, and only three of them claimed to have seen one in the past five years. These reported sightings, however, couldn't be verified. The scientists also underscored that two of the three recent sightings occurred in an area that lacked the seagrass beds needed to support dugongs and that those dugongs may have been drifters from the Philippine population.

The researchers acknowledged there may be a few surviving dugongs in the South China coastal waters might not have been detected by the respondents. However, the study's comprehensive assessment suggests that even if there are some individual dugongs remaining in the area, the massive population drop of the species in recent decades could not be stopped or reversed under current conditions.

Habitat degradation, seagrass depravidity, and hunting are to blame for the species' disappearance, the scientists said in the study. Previous studies showed that fishing and fish farms have degraded critical seagrass ecosystems in the northern South China Sea. And worldwide, around seven percent of seagrass habitat is lost every year, a 2020 UN report said.

And the researchers reported that, between 1958 and 1976, 257 dugongs were slain in the northern South China Sea for food. These animals are often caught and killed as fishing industry bycatch, according to reports cited by the researchers.

The International Union for Conservation of Nature (IUCN) has listed the dugongs as a species globally vulnerable to extinction , and are the precious marine mammals arelegally protected in many countries. Individual dugongs can live for more than 70 years, but its species have been found to breed slowly, which makes recovery and protection more difficult.