In this relaxing Minute, we invite you to swim alongside one of the more famous and beloved ocean creatures, the hawksbill sea turtle (Eretmochelys imbricata). These marine reptiles, and yes they are reptiles, have been roaming the world’s oceans for an incredibly long time. It is believed that the “Cheloniidae” family, the name of these marine turtles, has been living on our planet since the last Mesozoic Era, more than 100 million years ago! Making them some kind of living fossils.
Take your minute to swim alongside this hawksbill sea turtle
Their scientific name Eretmochelys imbricata, is derived from the Greek words “eretmo” meaning oar referring to its oar-like flippers and “chelys” meaning turtle. The second part of the scientific name “imbricata” comes from the English word ‘imbricate’, which means ‘having overlapping edges’, and refers to the overlapping scales of the Hawksbill’s carapace. There are currently actually 2 subspecies known to science, namely E. imbricata imbricata (a.k.a. the Atlantic Hawksbill), and E. imbricata bissa (a.k.a. the Indo-Pacific Hawksbill).
Ocean gardeners: Hawksbill sea turtles play a crucial role to keep up diversity on the reef
The Hawksbill is one of the smaller species of sea turtles, growing up to about a meter in length. It has a characteristically narrow, pointed beak and a beautiful patterned shell/carapace, which has serrated edges towards the lower end. These turtles are in fact omnivores that will dine on a wide variety of food sources, including jellyfish, corals, fish, anemones, molluscs, marine worms, crustaceans, and other plants and animals. However, Hawksbill turtles feed primarily on sponges.
They show a great level of feeding selectivity, in the way that they only eat certain species of sponges, some of which are toxic to other animals. But there is more to their diet. In fact, their type of feeding provides a great service to other marine life on the coral reefs. Without hungry hawksbill turtles, the reefs would quickly overgrow with sponges, taking the space for slower-growing corals to thrive. Hence, hawksbills play an important role in the ecosystem and contribute to the overall health of coral reefs and wider marine life.
It’s getting hot in here: hawksbill sea turtle (Eretmochelys imbricata)
Hawksbill sea turtles reach sexual maturity between 20 and 35 years of age (around 20 in the Caribbean and 30-35 in the Indo-Pacific). It is estimated that they can live between 30 and 50 years in the wild. Hawksbills will lay eggs every 2-4 years during those sexual mature years. Nesting is the moment when the female turtles, who have come back to the place of their own birth, leave the water. This allows observing them on the sand of small beaches, where they dig a nest to lay their eggs. Such a nest is usually about 50cm /19” deep.
After they have laid their eggs inside, they cover them with sand again. Each egg is approximately 36 mm in diameter and 28 g in weight. About 60 days thereafter, the young ones will hatch. Interestingly enough, temperature determines the sex of these hatchlings. When the temperature is around 29°C/ 84.2°F, the male-to-female ratio is about 1:1 in the nest. When the temperature rises, more female baby Hawksbills turtles will be born. If it drops, the baby Hawksbill turtle males will dominate the hatching. This fact is worrisome, not only to scientists, as the averages temperatures on our planet continue to rise.
Eretmochelys imbricata are critically endangered
Unfortunately, these beautiful creatures are critically endangered and therefore listed in appendix I of CITES, a multilateral treaty to protect endangered plants and animals, as well as the „Red list“ of IUCN (International Union on Conservation of Nature). These listings lead to the fact that the trade of this turtle’s beautiful carapace/shell has been made illegal, in an effort to conserve the population. Despite this, the Hawksbill turtle shell is still found in souvenirs and jewellery. In fact, it’s still the most frequently confiscated illegal item by customs officials …
This clip was filmed by Yoeri diving at Balicasag island, the Philippines, with a Sony V1p in an Amphibico housing in 2010. We have presented hawksbill sea turtles to you before. Watch „Take a Minute VIII“ or read more on Statia‘s sea turtles 1: Species, sex & individuals.