An accessible South Sea whale species could be resilient to near-future ecosystem changes, according to a new study by the universities of Exeter and Copenhagen.
Gray beaked whales living in the deep oceans of the Southern Hemisphere are rarely seen alive and their ecology has hitherto been a mystery to scientists.
The study used the genome sequence of 22 whales washed up on beaches in South Africa, Australia and New Zealand to study the history of the population over the past 1.1 million years.
Study author Dr Kirsten Thompson, from the University of Exeter, said: “The population doubled around 250 thousand years ago, coinciding with increased productivity in the South Sea, sea surface temperatures and potential expansion in a suitable environment. “
The average population appears to have high levels of genetic diversity and no “genetic structure” (patterns of genetic similarity in geographical areas), suggesting that whales leave their birth groups and move widely throughout their Southern Hemisphere range.
Based on these findings, this perfect match of high genetic diversity, a flexible social system and the rich habitats of the Southern Hemisphere means that Gray-beaked whales could be resilient in changing conditions.
“Human activity is causing rapid ecological change in every habitat on Earth, including the deep oceans,” Dr. Thompson said.
“We need to understand how different species might respond to these changes, but we do not have detailed knowledge of many animals, especially deep-sea whales such as Gray porpoises. “
It is impossible to obtain observational data on this species – they are small (five meter) whales, which spend most of their time below the surface finding and feeding on squirrels. – whales nicknamed “scamperdown whales” because they could not be carried.
The study used both mitochondrial DNA to study population history, and partial nuclear genomes to estimate population structure.
“Our findings show that numbers of Gray beaked whales have been relatively stable for the last 1.1 million years,” said Dr Thomson.
“The oceans of the Southern Hemisphere could support an amazing amount of Gray whales. Good news for at least one species.
“We’ll show how genomic tools can help reveal past history, current status and near-future potential changes in enigmatic, rarely rare animal populations. seen and outside the reach of traditional boat inspections. “
Story source:
Materials provided by University of Exeter. Note: Content can be edited for style and length.