Cultural Learning Drives Humpback Whale Recovery in British Columbia

Humpback whales in Northern British Columbia are demonstrating advanced cultural learning through the widespread adoption of bubble-net feeding, a complex cooperative hunting strategy. This technique requires precise coordination, involving one whale creating a curtain of bubbles to encircle prey, often herring, while others herd the fish before a synchronized lunge to feed at the surface.

A twenty-year longitudinal study conducted by researchers from BC Whales and the University of St Andrews documented the social transmission of this foraging expertise within the Kitimat Fjord System. Tracking 526 distinct individuals between 2004 and 2023 via photo-identification of tail flukes, the investigation logged 7,485 photo-identifications across 4,053 encounters. The findings, published in Proceedings of the Royal Society B, showed that 254 individuals, or 48% of the sample, utilized the learned bubble-netting behavior in 635 recorded instances.

Researchers suggest the recovery of the northeastern Pacific humpback population is intrinsically linked to the spread of this cultural knowledge, often introduced by immigrant whales from regions like Alaska where the tactic is long-established. The increasing use of bubble-net feeding is a significant factor supporting the local humpback population's resurgence, which now exceeds 500 individuals and is growing at an estimated annual rate of six to eight percent. Marine mammal ecologist Dr. Éadin O'Mahony of the University of St Andrews noted that retaining such cultural knowledge is essential for the species' long-term adaptability in a changing marine environment.

This cooperative method, which can involve up to sixteen whales working as a unit, increases food capture efficiency by up to seven times per lunge compared to solitary feeding. However, this vital foraging ground, situated within the Gitga'at First Nation territory, faces escalating pressures from proposed industrial expansion and increased shipping traffic near the port of Kitimat. Studies indicate that increased vessel traffic, particularly from Liquefied Natural Gas export terminals planned for operation by 2030, could lead to an estimated 18 annual humpback whale mortalities from ship strikes, a rate deemed unsustainable for the recovering population. The integration of animal culture into marine management strategies is increasingly viewed as essential for species protection amid intensifying human impacts on ocean ecosystems.