Scientists explore the real-life effects of the northern elephant seal barrier.

A northern elephant seal pup on a California beach, with an adult female in the background. Credit: Dan Costa, University of California

New research into northern elephant seals has revealed that their reproductive and foraging success has been affected by population bottlenecks that are driving them closer to extinction and could make them vulnerable to future climate change. Is.

The northern elephant seal is a popular species living along the highly accessible Pacific coast of Mexico and North America, coming ashore to breed. For much of the 19th century, they were hunted for the oil obtained from their blubber. They were thought to be extinct after the last few were captured in 1892.

Fortunately, there were about 20 survivors, and they made a spectacular comeback. Now, less than 150 years later, there are more than 200,000 of them in an apparently healthy and stable population.

The study, led by Durham University in collaboration with researchers from the US and China, revealed that despite the apparent full recovery, the blockage compromised key genes. and the ability of seals to forage effectively. “Genomics of post-disruption recovery in the northern elephant seal” is studied. published In the journal Nature Ecology and Evolution.

The research team analyzed nearly 270 northern elephant seals to explore their entire genetic makeup and compared pre- and post-harvests. Their results showed a very direct loss of diversity due to the bottleneck event and found that the overall fitness of modern populations was affected.

The researchers found three types of post-barrier effects, including reduced diversity, reduced reproductive success of females and males, and reduced diving performance. Together, leaving the species vulnerable to environmental stressors that may occur in the future.

An important aspect of the elephant seal’s life history is their extensive deep-diving excursion as they accumulate fat deposits to facilitate fasting. . Research shows that individuals affected by disruptions in specific related genes were less proficient divers.

Males fight for control of large harems of females for mating, but research has found that some males have been acquired. which harmed their reproductive capacity. For females, it was the overall loss of diversity that reduced their lifetime reproductive success.

“In this study we saw Genome-wide pre- and post-disruption of northern elephant seals. We found that post-barrier seal fitness was significantly affected by increased inbreeding, by the persistence of genes that had lost function, and by distorting the frequency of genetic variants throughout the population.

“So far, the species has recovered well, but these results raise the question of how sensitive it may be to environmental pressures in the future.”

More information:
Hoelzel, AR et al., Genomics of postdisruption recovery in the northern elephant seal, Nature Ecology and Evolution (2024). DOI: 10.1038/s41559-024-02337-4

Reference: Scientists Discover Real-Life Impacts of Northern Elephant Seal Barrier (2024, February 21) Accessed 21 February 2024 at https://phys.org/news/2024-02-scientists-real-life-impacts-northern. Retrieved from html

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