The Elusive Hawaiian Hawksbill
Last week I had the opportunity to join Hawai’i Hawksbills, Eastern Pacific Hawksbill Initiative (ICAPO) and members from NOAA’s Pacific Islands Fisheries Science Center on a mission to capture and tag Hawaiian hawksbill sea turtles.
Hawksbills are extremely rare within the Hawaiian Islands. In fact, in the 2 years that I’ve lived on Maui, I’ve only observed them while assisting HWF’s, Cheryl King with beach nesting work. Up until last week, I hadn’t seen one underwater while snorkeling/diving in Hawai’i.
Cheryl has been leading HWF’s Hawksbill Recovery Project since 2000. Along with her community network of hawksbill enthusiasts, she has gathered information and now knows the “hot spots” to find them, can identify them on site (based on their unique scute pattern), and each one has been named accordingly. For instance, “Rocket Girl” has a scale that’s shaped like a rocket on the top of her head. “Misty” has a partially colored scale as if it was disappearing into the “mist.” “Barnacle Billie” had a heavy load of barnacles growing on her when she was first sighted.
The hawksbill turtle is small to medium-sized when compared to the other sea turtle species. They are easily recognizable by their raptor-like beak and the beautiful, dark to golden brown, overlapping scutes on their shell. Adults grow to 200 – 250 lbs. and are most commonly found in areas associated with healthy coral reefs. Hawksbill turtles are listed as Endangered under the Endangered Species Act.
The team is studying Hawaiian hawksbills to try and gain a better understanding of its population abundance and trends. The population in Hawai’i is especially small with fewer than 100 adult females known to nest in the entire archipelago. Hawksbills are known to nest on the main island beaches of Hawai’i, primarily the south coast of the Big Island; however, much is still unknown about the in-water population. Studies such as this are extremely important to gain a better understanding of a distinct population of sea turtles, allowing for the development of an effective
We packed our gear, food, and water, boarded the boat and hoped for good weather.
We headed to the known “hot spot” on the island for hawksbills – just a quick 10 minute boat ride. Anyone that has spent time on the ocean around Maui knows the weather offshore can be unpredictable with windy conditions common each day beginning at ~11 am. We arrived at our spot around 9 and the water looked perfect, top – bottom visibility and just a small surface shop. Cheryl had been receiving word that five of the well-known turtles had been seen in this area over the past couple of weeks. It was decided that we should jump in and take a quick look around to a few of the known resting areas prior to beginning our actual surveys (swimming line transects).
Most of us spend the majority of our “work time” at a desk and behind a computer, so we were all anxious to jump in the water and start our search. The ocean has been much warmer than usual this fall – which is good if you’re one that gets cold easily; however, this has caused widespread bleaching across the island’s coral reefs.
We spent about 30 minutes looking around the area before deciding to return to the boat to driv
e further north to begin our thorough survey of the whole reef. We were all back on the boat except for Alex, a visiting hawksbill scientist (ICAPO). We spotted him in the water, quite a bit north of the rest of us, when he gave the sign. Alex had spotted the first hawksbill turtle of the day! Once he knew he had our attention, he disappeared underwater soon to return with a large, adult hawksbill in his hands. We were all ecstatic having only been on the water for 30 minutes and already the first turtle was captured. We brought the turtle onto the boat and Cheryl immediately identified her as “Rocket Girl”. She then contacted Don McLeish, who has documented her more than anyone, so he could swim out to the boat from shore to see her. The tagging team got to work and the rest of us couldn’t wait to get back in the water to find more hawksbills! It always boosts morale to find success early in a mission.
The first day of tagging was the most successful; all three hawksbills named above that were found were caught and tagged. All captured turtles received a pit tag (microchip similar to what would be used in a dog or cat), external metal flipper tags (identification, similar to a piercing) along with a satellite tag. Satellite tags help scientists gain an understanding of the movement of sea turtles. When the turtle swims to the surface to breathe, the tags transmit a signal that can be detected by polar orbiting satellites and then send in-water data that otherwise wouldn’t be able to be obtained (migration routes, dive profiles, ocean temperature, etc.).
Post-nesting females have been tagged and tracked by these groups on Maui and Hawai‘i Island, but this is the first time in history that in-water captures were outfitted with satellite transmitters in Hawai`i. Despite nearly 3 full days of more searching, no new hawksbill turtles were spotted. This shows how rare they are, and how challenging it can be to find them. It takes a lot of planning, an efficient network, a team of experts, and good ocean conditions! The team remained satisfied after such a productive day one. And besides, any day that can be spent snorkeling on beautiful coral reefs looking for sea turtles, is a good one.
To learn more about Hawai’i Hawksbill’s Hawksbill Recovery Project, click here.
To learn more about ICAPO’s work in the Eastern Pacific, click here.
To learn more about the NOAA Pacific Island Fisheries Science Center, click here.