Shrinking dugong populations losing genetic diversity: study

WELLINGTON, Aug. 7 (Xinhua) -- Dugong populations are becoming increasingly susceptible to human impacts and climate change, according to a study released on Wednesday.

Dugong numbers have been declining for a thousand years, and those in the western Indian Ocean have recently lost genetic diversity, the study said.

The new study of ancient DNA from dugong specimens in museums has mapped their genetic diversity in the Indo-Pacific and modeled their past populations.

The authors from New Zealand's University of Auckland and Norway's University of Oslo, said global dugong populations are becoming fragmented and less diverse, putting them at increasing risk from human activities and climate change.

Greater understanding of their global populations could identify particularly vulnerable groups for conservation priority, said the study published in the Royal Society Open Science.

Dugongs have been of cultural and economic importance in the Indo-Pacific region for millennia yet are exposed to a multitude of human threats, the study said.

The authors said scientists lack an understanding of dugongs' population structure, preventing the identification of vulnerable populations for conservation priority.

The study discovered that western dugongs have 10-fold lower levels of genetic variation compared to eastern dugongs and that this diversity has been declining during the 20th century.