Puako's shoreline: Tidepools and turtles

by B. N. Sullivan

Our favorite shore diving site is at Puako, on the Big Island of Hawaii. We used to live in Puako, and we still live just a few miles away, so over the years we probably have made more dives at this one location than at any other place on the planet. Naturally, we have spent a great deal of time exploring the shallow areas along the shoreline there as well.

Shoreline at Puako, HawaiiPuako's irregular shoreline was created by old lava flows. The most recent of these, from an eruption on the Mauna Loa volcano in 1859, flowed to the coast and well into the ocean where it cooled and hardened. Many fingers of black pahoehoe lava are visible along the Puako shoreline today. The rest of the flow now forms a basalt shelf that runs under the surface of the water for some distance seaward from the beach, then ends abruptly as a cliff-like dropoff.

In the photo at right, Jerry is wading on top of the lava shelf near the beach. In the background you can see waves breaking over the dropoff.

The water beyond that dropoff gets deep quickly, but the water depth on top of the inshore shelf is quite shallow. There are many tidepools along Puako's shoreline, thanks to the unevenness of the lava's surface.

The tidepools and shallows at Puako are full of life. There is plant life in the form of algae and seaweed (called limu in the Hawaiian language). There are many species of juvenile fish, which somehow find their way to the tidepools just as they pass from their larval stage into creatures recognizable as tiny fish. They remain in the tidepools until they grow big and strong enough to make their way to the reef community beyond the dropoff. There are creatures like crabs and tiny shrimp and various molluscs living in the tidepools and the near-shore shallows as well.

There is one much larger marine species that can be found in the shallows, tidepools, and even on the beaches and shoreline rocks in Puako. That's the green sea turtle (Chelonia mydas), one of the three sea turtle species native to Hawaii.

Green sea turtles are a very common sight at Puako. They graze on the seaweed that covers the rocks in the shallows, they rest underwater on ledges and in holes in the reef beyond the dropoff, and -- most remarkably -- they haul themselves out of the water along Puako's shoreline to bask in the sun.

Many newcomers and tourists become alarmed when they first spot the turtles on the beach or the rocks at Puako. They assume that the turtles somehow got stuck there as the tide receded, or that they might be injured. Sometimes it takes quite a bit of explaining to convince them that this is the natural behavior of these creatures. The basking turtles are not in distress, and they need no assistance to get back into the ocean. (Honest!)

Actually, no one is quite sure why the turtles bask here. Some scientists believe that the behavior serves as a way to elevate the turtles' body temperature. Others surmise that this is a way to avoid predation, especially by tiger sharks, which are known to favor turtle meals. We always joke that they're just 'working on their tans.'

Green Sea Turtles on the rocks at Puako, Hawaii
When you look at the two snoozing turtles in the photo above, you may wonder why they're called green sea turtles. They don't look green at all! The name comes from the color of their body fat, not the color of their scales and carapace.

In case you are curious, green sea turtles are not known to nest in this area. Most of the turtles that live in the area around Puako are not yet sexually mature. They are at a sub-adult stage of life more or less equivalent to being an adolescent. They spend their time at Puako feeding and lounging around until they mature. Then they migrate some 800 miles to the uninhabited northwest Hawaiian Islands -- especially the area around around French Frigate Shoals -- to mate, nest and lay their eggs. This pattern has been documented through long-term tracking studies of tagged turtles.

If you've ever wanted to see one of these creatures -- or up to fifteen at once! -- Puako is the place to do that. Just don't touch or harass them. Honu, as they are called in Hawaiian language, are a threatened species, legally protected by both Federal and State laws.

UPDATE Oct. 1, 2007: We are proud to tell our readers that this article has been included in the second Carnival of Aloha -- a blog carnival devoted to Hawaii, hosted by Evelyn at Homespun Honolulu. Thank you Evelyn for including The Right Blue, and for your efforts on behalf of Hawaii bloggers. Aloha from the Kohala Coast!


  1. very well!!! Good work!!
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  2. Thank you for visiting, CrisOli.

  3. Well, I had no idea about yet another great blog you help run Bobbie!

    Puako shoreline does look outstanding! Your photos are fantastic!

  4. I woke up this morning thinking that I want to visit my favorite tidepool/honu beach before the next edition of the Carnival of Aloha so I can submit a post about it, lol! Great minds and all that stuff, I guess. Mine is on the Waianae Coast and I'll tell all about it soon, even if the idea won't be original to the carnival. :0) Mahalo for sharing the Puako shoreline so beautifully!

  5. @ Sheila

    Next time you and your husband come to the Big Island, get in touch and we'll take you to Puako to see the turtles.

    @ Skeet

    Nice to hear from another honu-lover. I didn't know that the turtles were 'working on their tans' over on the Waianae coast of Oahu as well.

    If you write an article about the honu on your island, let me know, and I'll link to it.


  6. Bobbie, I posted about a turtle that lives in Waianae Boat Harbor back in June. One of my regular readers, who works with terrapin in Malaysia, thought it was a hawksbill, but I was pretty sure it was a green. I posted another picture with the scutes more visible the next day and confirmed that it was as green sea turtle. Here's a link to the first post, with alink to the second in the comments:


    I'll go to the secret/locals only beach soon and get some photos of our friends working on their tans.

    Lucky we live Hawaii? No question about it! :0)

  7. Hi Skeet -

    Thanks for the follow-up with the link to your post(s). The Waianae turtle looks like a green to me, too.

    It also looks like it needs to swim on over here to the Big Island for a cleaning. There's a well-known turtle cleaning station at our favorite dive site in Puako (and come to think of it, that would be a good topic to write about!).

    Here's another turtle ID resource, from NOAA:



  8. Hi Bobbie,

    Thank you so much for your very kind offer!! I hope to take you up on it sometime.

  9. Aloha Bobbie,
    Nice to meet you through the Carnival of Aloha! It is always exciting to me to know of another Big Island blogger!

    Really great article about Puako.

  10. This is a great post, Bobbie! Great pictures and cool information! I need to find out from skeet just where those guys are that she's talking about. I have heard other people say they see turtles on the Waianae Coast, but for all the years I lived there, I never saw them. We used to hang out on the reef just past Makua cave, along the shoreline in Maile (getting cut up on the reef... good fun!) and hanging out at Pokai Bay and Rest Camp. I must say that the boat harbor was not a place I used to go, that much I do have to admit. Maybe I'm just blind to them unless they're swimming right next to me! :) I dunno! Anyway, love this post and I can only imagine just how beautiful the shoreline is up close and personal! :)

  11. Hi HVG and Evelyn -

    Thanks for stopping by and for your nice comments. Looks like we will have to include both of you guys in our honu lovers' group.

    I will be doing some more posts about our Puako turtles, so check back from time to time.

    Malama na honu!


  12. P.S. to my friends on Oahu. Another place we used to see honu on your island was up north near Haleiwa. Anyone know if they're still found around there?



We welcome your comments and invite your questions. Dialogue is a good thing!

Bobbie & Jerry