Clad in a black wet suit and pink face mask, Jin So-hee's figure cleanly parts the green-blue water until she abruptly dives below the surface, her purple fins disappearing into the deep.
When she resurfaces a minute and a half later, her gloved hands grip six or seven sea cucumbers, their spiked backs glistening in the sun.
But climate change may permanently dash their hopes of spending their lives working as free divers.
"I thought that as long as my body is healthy, I could have been the oldest haenyeo when I'm 90 or 100," Jin told Reuters.
"Now that I think about it, my health is not the only concern. I’m worried this job will change drastically or even disappear because of climate change."
Left: Haenyeo sell seafood that they harvested in the sea, on the port in Busan. Right: Sea urchins.
As recently as the 1990s, scientists would see one or two subtropical species around the islands of Korea's south coast, but a study covering the years 2012-2020 found 85 kinds of subtropical species, accounting for more than half of all sea life in some places, Ko said.
Since 2011 the government has also been working to reverse the ocean desertification caused by climate change.
Left: Haenyeo Ko Keum-sun, 69, carries sea food that she harvested in the sea. Right: A haenyeo wears diving weights.
With less seaweed, which the haenyeo also harvest as food, the women increasingly have to dive deeper, Jin said.
That's more physically challenging, and the women say they have to deal with more pollution as well, further complicating their already dangerous jobs.
"The problems seem very real to us," Woo said after evaluating her diminished catches and tallying up her totals for a recent pay day.
"Today, I'm thinking once again, 'This is really serious.'"
PHOTO EDITING MARIKA KOCHIASHVILI; TEXT EDITING TOM HOGUE;