The Republic of Korea’s all-women extreme divers, who sell their catch through fishery co-ops, are well-known for diving without oxygen, something they have been doing since the 17th century.
However, a recent study found that the women, who spend their days dive off Jeju Island to harvest seaweed, ablone, and other seafood, have undergone genetic adaptations as a result of their activity.
The study compared the results obtained by Haenyeo divers with those of age-matched populations in Jeju and Seoul. The researchers performed cardiovascular measurements at rest and during a series of simulated dives, measured baseline metrics associated with diving physiology, including spleen size, and examined whole genome sequencing (WGS) data.
Locally known as Haenyeo, or “women of the sea”, the divers, many of whom are now in their 70s and 80s, are four times more likely than mainland Koreans to have a genetic change linked to lower blood pressure while diving. According to the study, they also have greater tolerance to pain, specifically against cold-based pain, which enables them to continue diving, even when air temperatures off Jeju Island drop to zero degrees Celsius.
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The women’s typical diving occurs at depths of maximum 10 metres and for a short duration of under 30 seconds. The study also elucidated the question of how Haenyeos can continue to dive throughout pregnancy. The lower blood pressure while diving keeps the women and their unborn children safe even when they dive during pregnancy.
There are over 3,000 female divers in Jeju, who are members of fishing co-operatives on the island, represented by the National Federation of Fisheries Cooperatives, which has over 150,000 members nationwide.
While diving on the islands was initially a male trade, women started diving in the 17th century to earn a living for their families, after losing men in different conflicts. Since then, diving rights have been passed on from mother to daughter. Each fishing village co-operative is allocated a specific diving area. Being part of a co-op means the catch gets collected jointly and divers earn an equal amount.
The current Haenyeo population has an average age of 70 years, which means these women may be the last generation of Haenyeo divers. While the practice is dying, the Korean authorities have tried to preserve it including by opening Jeju Haenyeo Museum in 2006. Unesco also recognised the practice by listing the Jeju Haenyo divers as an Intangible Cultural Heritage.
The study was carried out by US university researchers.
Image: Haenyeo divers on Jeju Island (Serhat Akkan/Anadolu via Getty)
