Thursday, November 30, 2023

Swimming with green sea turtles

Green Sea Turtle Taking Breath, Avaavaroa Passage, Rarotonga, Cook Islands

I really needed just one picture of a green sea turtle for an upcoming project, but pictures are often better when I get the chance to know my subject on a deeper level. And I’m very thankful for the hours I got to spend with the turtles off Rarotonga in the Cook Islands.

This wasn’t my first time with them. Earlier in my career I got to see an unusual group of the turtles on Hawai`i. The turtles there spend afternoons resting on the beach, possibly because they face an unusual threat from tiger sharks. For their relatives in other parts of the world, the primary enemy is fishing nets.

Green Sea Turtle, Honu (Chelonia mydas), Punalu`u Black Sand Beach, Hawaii

Virtually everywhere else the green sea turtle is found, it lives up to the “sea” part of its name. Even breeding females only come to shore for a few months every 2 to 5 years — just long enough build a nest and deposit eggs. In the Cook Islands, I finally got to see how they live at sea.

The turtles have a substantial range. I didn’t have to go to the Cook Islands to see them. They’re found in tropical and subtropical waters throughout the world. But in the Cook Islands I got to work in relatively clear and calm conditions.

The country is comprised of 15 islands. About half the islands are the tops of extinct volcanoes. The rest are byproducts of them. Most are largely encircled by coral reefs that keep the pounding Pacific Ocean waves hundreds of yards from the beach. In between are spectacular lagoons.

While the green sea turtles may have a range that’s large, their populations are not. They are endangered. I had hoped to see them among the coral in the Aora Lagoon Marine Reserve on Rarotonga. The snorkeling conditions there are some of the best on the island. But after more than a dozen hours of trying over several days, I could not find a single one. Fortunately, there are other options.

Ten minutes away by car there is a place where turtle sightings are practically guaranteed. It’s called the Avaavaroa Passage. As the name suggests, it’s a channel of deeper water that extends through a break in the barrier reef out into the open ocean. Where I could frequently touch the bottom of the lagoon, in the passage I often can’t see bottom.

Green Sea Turtle, Avaavaroa Passage, Rarotonga, Cook Islands

In the passage, it didn’t take long for me to spot my first green sea turtle. I was swimming out to a spot locals have dubbed Turtle Café. I noticed a turtle fading into view as it approached the surface. It’s swimming much faster than I can go, even with my flippers. It could come up for a breath anywhere, yet it chooses to emerge a few arm lengths away.

For the first time I can appreciate how large they are. It’s close to 4 feet long and I’m told it can weigh 350 pounds. For the grace with which it moves through the water, however, it appears featherlight.

Green Sea Turtle Diving, Avaavaroa Passage, Rarotonga, Cook Islands

It’s at the surface for just a few seconds and then dives toward a coral shelf along the passage. It nestles itself into a cranny and settles in for some rest.

Turtle Café is a popular hangout for the turtles. In parts, the coral nearly reaches the surface of the water. There are also perches about 10 feet down. A quick scan of those will likely reveal a turtle.

Green Sea Turtle Resting on Coral, Avaavaroa Passage, Rarotonga, Cook Islands

My time with the turtles is limited to low tide. It’s the safest time to be in the passage and also gives me a closer view when they are at rest. But even though the water level is lower, the water is not clear enough for me to be able to see them when they drop down to feed on seagrasses.

Green Sea Turtle Swimming, Avaavaroa Passage, Rarotonga, Cook Islands

My best view of them is when they come up for air. I got several opportunities, even though they can hold their breaths for exceptional lengths of time. At rest, they can hold their breath for up to 5 hours. They accomplish this by slowing their body systems. While they’re resting, their heart may beat only once every 9 minutes.

When they’re active, however, the intervals are shorter, although still quite long. They often go a half hour to 45 minutes between breaths.

Green Sea Turtle Swimming, Avaavaroa Passage, Rarotonga, Cook Islands

During the few hours that I spent with the turtles, I never had to wait more than 10 minutes for one to surface near me. I don’t know if they were curious about me or just being friendly, but it was wonderful to be accepted into their world.

(Prints of Kevin Ebi's images are available through Learn about new work by joining his mailing list.)

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