Elephant seals bouncing back from brink of extinction
A new international study has found the genetic impact of hunting of northern elephant seals. Published in Nature Ecology and Evolution, the research has found that the species narrowly escaped extinction from hunting, and this has led to lasting genetic effects on the surviving population.
Fifteen researchers, from Germany, the UK, and US, from seven universities and four research institutions collaborated for the study that was led by Bielefeld University.
At the beginning of the 20th century, northern elephant seals were on the brink of extinction as a result of hunting. “Genetic analyses suggest that the population was likely reduced to fewer than 25 animals at that time,” according to Professor Dr Joseph Hoffman, lead author of the study and head of the Evolutionary Population Genetics group at Bielefeld University.
Such huge population declines can be detrimental to a species’ genetic diversity. This increases the danger of inbreeding and threatens the survival of the species.
Since then however, the population of northern elephant seals has bounced back to around 225,000 animals. The study from the Journal Nature Ecology and Evolution examines how this has impacted the genetic diversity and health of the animal.
The team combined genetic data, health records, modelling of population sizes, and genetic simulations. They found that the sharp population decline has resulted in the loss of both beneficial and harmful genes among the northern elephant seals. This pattern was not observed in the closely related southern elephant seals which have not seen a similar decline.
“The highly reduced genetic diversity, including the loss of beneficial gene copies,” Professor Dr Kanchon K. Dasmahapatra from the University of York, UK, who is the senior author of the study warns, “may impair the ability of northern elephant seals to cope with future environmental changes, including those caused by anthropogenic climate change, changes to the species’ habitat, or even natural threats such as disease outbreaks.”
