November 30, 2023

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The study shows that whaling has led to a loss of genetic diversity

The study shows that whaling has led to a loss of genetic diversity

Photo: Thomas Kelly // Unsplash


New research from Oregon State University examined the genetic impact of 20th-century commercial whaling. new paper, Published in the journal GeneticsIt describes the loss of genetic diversity in whales surviving today, specifically the maternal lineage of blue whales and humpback whales.

Researchers compared DNA from whale bones found on beaches near abandoned whaling stations to current whales. The bones were found primarily on South Georgia, an island in the South Atlantic Ocean, 800 miles southeast of the Falkland Islands. The prevalence of commercial whaling in the area, combined with the cold temperatures that helped preserve specimens, resulted in a large number of discarded bones available for analysis. The study explained: “It is known that these bones represent the first stage of whaling in the twentieth century, and thus the diversification of these groups before whaling.” “Post-whaling diversity has been described by previously published studies reporting extensive sampling of live whales in the Southern Hemisphere.”

The result was that researchers found strong evidence of loss of maternal DNA lines among blue whales and humpback whales. “Maternal lineage is often linked to an animal’s cultural memories, such as feeding and breeding sites that are passed down from generation to generation,” said Angela Sremba, lead author of the study. He told the Oregon Newsroom. “If the maternal lineage is lost, this knowledge will likely be lost as well.” As a result, local whale populations have largely disappeared from South Georgia.

However, since commercial whaling stopped, whales have begun to return to the island. “The numbers of whales returning to this area today are still not large, but there is a feeling that they may be rediscovering this habitat,” said Scott Baker, Ph.D., associate director of the Marine Mammal Institute at Ohio State University. Srimba Advisor. “This provides the opportunity to document the natural reconstitution of these former feeding grounds, similar to what has been documented for the southern right whale around New Zealand,” the same study explained.

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Although whales are beginning to return to the area, the effects of commercial whaling could still be felt for years to come. Since some whale species can live up to 100 years, it is likely that a number of whales living today were alive during the era of whaling. When they die, this may lead to the loss of more maternal lineages. “It is important to continue sampling these populations to monitor recovery and determine whether the recovering populations are remnants of pre-whaling populations in South Georgia or represent the rediscovery and colonization of this productive feeding habitat,” the study concluded.

“It is remarkable that these species have survived. “In another 100 years, we don’t know what might have changed, and we can’t measure any change now if we don’t have a good understanding of the past,” Sremba added. “This work provides an opportunity to reconstruct the history of populations.” “These whales and help us understand what we’ve really lost due to whaling activities.”