DNA study shows Madagascar’s dugong are very unique.
September 12, 2019
The Dugong and Seagrass Project received a press release from Auckland University in New Zealand about a recent genetic investigation published in the Journal Plos One by their scientists comparing dugong populations across thier range. Results indicate the genetic uniqueness of the dugong in Madagascar. Press Release follows:
Scientists at the University of Auckland in New Zealand, have used historic DNA to discover some of the highest-risk populations of the endangered dugong are genetically very distinct from other dugong populations.
Scientists have long known Indian Ocean dugong populations are most at risk, particularly the Madagascar dugong which this study shows is of a separate and unique genetic lineage and which diverged from other populations millions of years ago.
“Similar to New Zealand’s critically endangered Maui’s dolphin, the Madagascar dugong is genetically unique according to the work we have done, and this really confirms our worst fears in terms of their survival,” says Dr Shane Lavery from the University of Auckland who worked on the study.
“The study confirms there is a very low level of gene flow between geographically isolated dugong populations so that if they disappear, we won’t just lose a few more dugong, we will lose genetically distinct animals which, once lost, can never be recovered.”
This latest research is the first to use ancient DNA from museum and university collections to carry out such a broad-based genetic study of dugong. Scientists used historic DNA, some more than 250 years old, because the scarcity of live animals means samples are increasingly difficult to collect.
The historic DNA was painstakingly extracted from bone and teeth specimens collected between 1827 and 1996 from 162 individual dugong specimens. Fragments from the extinct giant 9m-long Steller’s sea cow, closely related to the dugong, were also used in the study.
“We hope that by showing the Indian Ocean dugong and in particular the Madagascar dugong are experiencing rapid biodiversity loss, we will contribute to more informed conservation decisions for this quite remarkable animal,”
Funding for the study came from the Western Indian Ocean Science Association and Ocean Park Hong Kong Conservation Fund with additional support from the Convention for Migratory Species in Abu Dhabi in the United Arab Emirates.
The study is published in PLOS One and available here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0219350