Researchers from Oregon State University examined how industrial whaling in the 20th century affected large whale populations, focusing on blue and humpback whales. Their findings indicate that commercial hunting did more than reduce numbers; it also diminished genetic diversity within these species, a consequence that could influence resilience to environmental changes. The study appears in the Journal of Heredity, signaling a rigorous, peer‑reviewed contribution to understanding whale population genetics.
To explore this, scientists compared ancient DNA from whale bones found along beaches near old whaling stations on the windswept island of South Georgia with the genes circulating in contemporary whales. The genetic analysis uncovered a loss of maternal DNA sequences in living populations, suggesting a disruption of maternal lineages over time.
As Angela Sremba, the study’s lead author, explained, the maternal lineage carries more than just biological information. It embodies cultural memories of migration routes, feeding territories, and breeding grounds that are transmitted from one generation to the next. When the maternal line erodes, this inherited knowledge can fade as well, potentially altering how populations navigate feeding grounds and find mates in a changing oceanic landscape (citation: Journal of Heredity).
Estimations show that more than two million whales were killed in the Southern Hemisphere during the 20th century, with about 175,000 deaths recorded near South Georgia. The area remains dotted with whale bones, a reminder of the era, and the bones have remained well-preserved thanks to the region’s persistently low temperatures, aided by its proximity to Antarctica (citation: Journal of Heredity).
As commercial whaling ended, the South Atlantic whale population began to recover, yet modern researchers note that these whales seldom approach South Georgia anymore. Scott Baker, deputy director of the Marine Mammal Institute at Oregon State University, interprets this as evidence of the local population’s near total destruction and subsequent re‑colonization by survivors and their descendants. The result is a landscape where whales must locate new migratory corridors and feeding grounds, a shift that has implications for ecosystem dynamics in the region (citation: Journal of Heredity).
In prior work, scientists explored protective measures for humpback whales that would not unduly burden crab fisheries. The evolving conversation around conservation in these waters continues to balance species recovery with the livelihoods of communities that have depended on maritime industries for generations (citation: Journal of Heredity).