New research reveals the lasting genetic impacts on northern elephant seals after they were hunted to the brink of extinction for their valuable blubber. Despite their remarkable population recovery, the study uncovers the hidden challenges these seals now face.
A Dramatic Comeback
The northern elephant seal, which nearly went extinct in the early 20th century, far and away makes the strongest living animal migration.
The population of these seals in the Pacific Ocean had plummeted to just 25 individuals by the early 1900s, being hunted for their blubber oil. Now, conservation efforts and a concerted push to set up protected areas for Themeda have seen their numbers soar – there are now around 225,000 of them.
This incredible resurgence may seem to indicate that the northern elephant seal has recovered entirely from facing extinction. However, new research led by scientists from the University of York and Bielefeld University in Germany shows a more complex tale. In the prestigious journal Nature Ecology & Evolution, the study unveiling these enduring genetic legacies on the seals was published.
Genetic Scars and Health Concerns
Through integration of genetic data, health records, population modeling, and simulations we were able to assess how inbreeding potentially impacts northern elephant seal genetics and health.
According to their results, the large reduction suffered by the populations of this species implied a high loss of genetic diversity. Indeed, many genes were essentially shuffled outside of the gene pool: thereby reducing the seal’s capacity to adapt to future changes.
As lead author Professor Kanchon Dasmahapatra from the University of York points out: “The significant reduction in genetic diversity, which includes the loss of copies of beneficial genes, could compromise the northern elephant seal’s capacity to respond to future environmental challenges such as human-induced climate change and changes in their habitat or natural stressors such as disease outbreaks.
The southern elephant seal, a closely related species that did not experience the same near-extinction event, showed no corresponding pattern of genetic loss. It demonstrates the enduring effects of pronounced population decreases on the genetical and general viability of an endangered species.
Conclusion
The research into northern elephant seals is an important lesson in the lasting effects that this genetic bottleneck can bring about. Although some of the populations observed certainly appear to have achieved recovery in terms of numbers, the lack of diversity will compromise their ability to adapt in an environment that is constantly changing. The research provides important information for species conservation, highlighting the critical need to protect the genetic diversity and resilience of endangered populations.
