Seemingly Common But Critically Endangered
The wreck of the USS Kittiwake in Grand Cayman is a crowd-pleaser of a dive. Now 15 years underwater, it lies on its side but is still easy to explore inside and out.
Rich, colorful sponge growth flourishes on the port side, which now faces down, away from the sun. Platoons of parrotfish and tangs work the algae-covered decks as sergeant majors make use of the smooth metal and lay their eggs on the superstructure. Stingrays and eagle rays often patrol in the sand.
My attention is on a hawksbill turtle (Eretmochelys imbricata) that is gently sculling along the wreck. My buddy, Jess, and I accompany it, only peeling away as another dive group closes in. The hawksbill doesn’t seem to care about the visitors, and we enjoy watching the other divers’ eyes widen and bubbles increase in excitement.
This turtle has clearly seen it all before, passing through the group and making a beeline for an outcrop of sponges. A few minutes later we spot a second, smaller individual also approaching for a snack. This one is a little shier and swims a little faster to reach the shelter of the metal.
Divers enjoy encounters with hawksbills across the Caribbean and throughout the Indo-Pacific, from the Red Sea and South Africa to the western coast of the Americas. No tropical diver could claim hawksbills are an unusual sight, but they are always a special one.
Strange Tastes
Caribbean hawksbills eat a lot of sponges, which is surprising because sponges are laced with toxins and packed with tiny, glassy spikes. Although their diet varies considerably from place to place, hawksbills seem to specialize in making delicacies of unpalatable, toxic, spiky, stinging marine life.
Divers will commonly see them feeding on sponges, soft corals, jellyfish, corallimorphs, anemones, and hard coral polyps. They’re also known to eat algae, mollusks, tunicates, crustaceans, and even sea urchins. These turtles are single-minded about their meals. If you accidentally disturb one while it is feeding, it will usually head up for a few breaths before returning to the same sponge or soft coral.
On the hard-coral-dominated reefs in the Indo-Pacific, sponges often grow as an understory below branching corals, and hawksbills will regularly pull apart the reef with their beaks and flippers to access them. Breaking apart the reef is good for scavengers and usually attracts a gang of wrasses, hoping the commotion disturbs a tasty crustacean. Angelfish also eat sponges and often follow turtles around, benefiting from the hawksbill ripping through the outer layers with its strong beak.
In the Caribbean it is common to see French, gray, and queen angels hanging out with feeding hawksbills, while in the Indo-Pacific I mostly see emperor angels taking over this role.
The other association I enjoy involves the predatory cheeklined wrasse, which I have seen in many locations across the Indo-Pacific using a hawksbill as cover. Most small reef fish ignore the benign presence of a hawksbill, but the wrasse exploits it, swimming in the shade just below its belly and darting when close enough to strike. In a few places this wrasse species has learned to do the same trick with divers.
A Face To Remember
Hawksbills share their habitats with green turtles, and divers regularly confuse the two. Most guidebooks will tell you to focus on the details: Hawksbills have overlapping scales on their shells, a more hooked
beak, and a square of four scales rather than two between their eyes. Most divers don’t notice these
things while enjoying a turtle encounter. The two species’ bodies differ in appearance in various ways, and it is better to learn to recognize how they look rather than any
single detail.
Like all turtles, hawksbills hatch from eggs that the mother lays high up on the beach, ideally under or near vegetation. Hawksbills favor small and isolated beaches with little sand and a rocky approach, usually in the same area where they were born.
Females typically lay three to five nests through the summer, with each clutch averaging around 150 eggs. Curiously, the incubation temperature of the nests determines the sex of baby hawksbills. On an unusually warm beach in Brazil, for example, 90% of the hawksbill hatchlings were female.
After about two months of incubation, the hatchlings emerge from the sand at night and make their way to the water. They orient seaward by heading toward the brightest horizon — the ocean — and away from the darkness of land.
In the first few years of their life, hawksbills inhabit open ocean environments, taking shelter under drifting sargassum mats and feeding on a wide variety of food. Once they reach around a foot (0.3 meters) in length, after the first few years of life, they head toward land, the reefs, and their adult lives.
Adult hawksbills are between 2 and 3 feet (0.6 to 0.9 m) long and weigh 100 to 150 pounds (45 to 68 kilograms). They typically reach maturity when 20 to 35 years old and are estimated to live 50 to 60 years, so if you dive in the same place over the years, you have likely seen some individuals several times.
Vanishing Act
Chances are good that you’ve seen a hawksbill if you have done at least a week or two of diving on coral reefs. Most divers will have seen many of them, so it may seem surprising to learn they are listed as Critically Endangered, the highest status before Extinction, on the IUCN Red List of Threatened Species.
To put this in context, the hawksbill is more at risk than the African elephant and any tiger or chimpanzee. Land mammals that share the Critically Endangered status include the black rhino, the Amur leopard (the world’s rarest large cat), and the Javan rhino, of which there are around 50 remaining.
About 20,000 nesting hawksbill females remain, but their population total is trending down. When I was younger they were simply Endangered, but a population decline of at least 80% over the past three generations has been alarming. They were designated as Critically Endangered in 1996 and maintained that status in their last global population assessment in 2008.
So why is our perception so different from their reality? Hawksbills are slow-growing and long-lived, but the concern is where the next generations are coming from. Many of the hawksbills we see aren’t mature and probably won’t make it to breeding age.
Hawksbills were heavily targeted for their beautiful carapace and value as food. While the global tortoise-shell market has been curtailed, they are still hunted for the Japanese bekko industry of luxury hawksbill-shell items. The World Health Organization warns against eating hawksbills, because their bodies are filled with sponge toxins that the turtle can cope with, but they can cause kidney disease, liver cancer, and even death in humans.
Untargeted fishing is just as deadly. Many hawksbills are killed when they are unintentionally captured or get tangled in fishing gear and drown. Abandoned or lost gear is just as deadly.
Other big issues come with human coastal development activities. Even if turtles live long enough to reproduce, they may not breed successfully. Converting wild beaches to human environments disrupts the natural movement of sand between the sea, the beach, and the dunes, typically leading to beach erosion. Beach erosion and the sea walls we install to prevent it rob hawksbills of suitable nesting habitats.
Our nocturnal light, noise, and movement near these beaches exacerbate the problems, scaring away females or disturbing them during nesting. Light is also a big problem for the hatchlings, which have evolved to head toward light, as the horizon over the sea is always brighter at night than the shadowy land. That instinct works until we put electric lights on land, which disorients the babies, causing them to die exhausted without making it to the water.
Turtles have been in the oceans since before dinosaurs stomped across North America. But hawksbills, though widespread, are struggling now in the Anthropocene. Their decline is partly due to active hunting of adults and eggs, but much of it is inadvertent, as they die as bycatch or victims of ghost fishing. These losses mean the species fails to spark the next generation as we disrupt nesting beaches.
It always makes my day when a turtle cruises through my dive, so we should return the favor. When we see a hawksbill, it should remind us to spread the word about bycatch, ghost fishing, and artificial light around nesting beaches.
Engaging the dive community about the challenges facing hawksbills could make a big difference for these ancient mariners.
Jelajahi Lebih Lanjut
Learn more about hawksbill turtles in this video.
© Alert Diver – Q3 2026