Meet the 5 species of sea turtles of Honduras

Anyone who has had the opportunity to observe a sea turtle coming ashore to nest will know how majestic an encounter with one of these animals can be—and even more so for those who have seen them swimming during a dive or while snorkeling! Out of the water, these animals may appear somewhat clumsy and slow. They usually seem larger than we expected, and when they finally return to the water, they surprise us again by taking off at full speed. On the other hand, the moment when the small hatchlings emerge from their nests has become a tourist attraction, as it offers a chance to witness up close the wonders of nature constantly renewing itself (or at least for as long as we allow it…).

Honduras is a privileged country when it comes to sea turtles. Of the seven species that make up the superfamily Chelonioidea, five roam our waters and some nest on our beaches. Unfortunately, all of them are listed in some category of extinction risk according to the IUCN Red List of Species. Within this superfamily we find the family Dermochelyidae, composed of a single species: the incredible leatherback turtle Dermochelys coriacea, the largest turtle in the world (Figure 1).

Leatherback Turtle (Dermochelys coriacea)

Unlike other sea turtles, the leatherback lacks a hard shell and its body is covered by a thick layer of fat and leathery skin that gives it its name. It feeds mainly on jellyfish, which often leads it to mistakenly ingest plastic bags floating in the sea. This is considered a major threat to the survival of these animals, as it damages their digestive system (Eckert et al., 2012). Although the leatherback occurs in both the Pacific and Atlantic Oceans, in Honduras it is only known to nest along the northern coast in communities such as Plaplaya in La Mosquitia (Eckert, 2001) and Punta Sal.

Figure 1. The leatherback turtle (Dermochelys coriacea) is the largest turtle in the world and nests on beaches along the Honduran Atlantic coast. Credit: IUCN Jean-Christophe Vié.

Olive Ridley Turtle (Lepidochelys olivacea)

The remaining sea turtles, which are smaller in size, belong to the family Cheloniidae, which includes the olive ridley turtle Lepidochelys olivacea. This is the smallest of the sea turtles and, despite being considered the most abundant, it is listed as Vulnerable on the Red List of species (Figure 2). It is recognized worldwide for its mass nesting events known as “arribadas,” which occur on certain beaches, including some along the Pacific coasts of Mexico and Costa Rica (Márquez, 2002). In Honduras, these turtles nest in the southern region of the Gulf of Fonseca in places such as Punta Ratón, Cedeño, and Playa del Venado in Marcovia.

Figure 2. The olive ridley turtle (Lepidochelys olivacea) is the smallest of the sea turtles and despite its relative abundance it is listed as Vulnerable on the Red List of species. Credit: IUCN Joëlle Dufour.

Hawksbill Turtle (Eretmochelys imbricata)

The remaining three species are more closely associated with the Honduran Atlantic, where they can be observed during dives and even nesting on beaches within the island territories that form the Bay Islands Marine National Park (PNMIB). The hawksbill turtle Eretmochelys imbricata has the highest threat category according to the IUCN (Critically Endangered) (Figure 3). This is largely because hawksbill turtles have historically been subject to trade in their shells for luxury decorative objects, despite international trade being banned under the Convention on International Trade in Endangered Species (CITES) since 1977. In addition to this, hawksbill turtles face similar threats to those affecting other sea turtles, which we will discuss later. A particular characteristic of this species is that it feeds mainly on marine sponges, which are highly toxic and harmful (almost like glass) to most other animals.

Figure 3. The hawksbill turtle (Eretmochelys imbricata) is one of the most sought-after due to its beauty. However, it has the highest threat category according to the IUCN, being listed as Critically Endangered. Credit: IUCN Nicolas Pilcher.

Loggerhead Turtle (Caretta caretta)

Another species found in our island region is the loggerhead turtle Caretta caretta, which has been reported in both Utila and Roatán and may also occur in the Swan Islands (McCranie et al., 2017). The diet of this species is less specialized and consists mainly of various types of benthic invertebrates from the sea floor (Dodd, 1988). In Honduras, its nesting events are more sporadic, especially compared to those of the hawksbill turtle.

Figure 4. The loggerhead turtle (Caretta caretta) has been reported in both Utila and Roatán and may also occur in the Swan Islands. Credit: IUCN Howard Hall.

Green Turtle (Chelonia mydas)

Finally we come to the green turtle Chelonia mydas. This is the species represented by Crush and Squirt, characters from the movie Finding Nemo. The green turtle is listed in the second highest category of extinction risk (Endangered), with severely fragmented and declining populations. Unlike other sea turtles, adult green turtles are almost exclusively herbivorous, feeding on algae and mainly on seagrasses, which they crop at the tips without consuming the entire plant. Although they can be seen while diving or snorkeling in the Bay Islands, the only report of nesting by C. mydas in Honduras has been in the Pacific, and the researchers themselves emphasize how rare this event is (Cruz et al., 1987). Other researchers have additionally reported the presence of juvenile hawksbill turtles in the southern region (Dunbar et al., 2020).

Figure 5. The green turtle (Chelonia mydas) is the sea turtle species in Honduras with the highest risk, as it is listed in the second highest category of extinction risk (Endangered), with severely fragmented and declining populations. Credit: Andrea Izaguirre.

Injury problems in the Bay Islands

Any occasion is a good time to share information about sea turtle biodiversity, and at Honduras Neotropical we believe it is necessary to talk about reports from the Bay Islands in recent weeks [2021] regarding injuries and mortality among sea turtles. From the island of Utila, the Bay Islands Conservation Association (BICA) reported on March 23 the injury of a green turtle that became entangled in a gillnet, a type of fishing net that is not environmentally friendly and whose use is prohibited within the Bay Islands Marine National Park. Fortunately, this story had a happy ending: the turtle was freed and the injury to its front flippers was treated by veterinarians at Jasper’s Utila Animal Shelter, who after keeping it under observation for 24 hours released it back into the sea.

Figure 6. Detail of the rear flipper of a hawksbill turtle that was found injured. Image credits © Kristie Jackson.

On the same date, but in Roatán, the Roatan Marine Park reported three fatal collisions between sea turtles and boats. The images are very striking but necessary to raise awareness about a problem that is rarely discussed. It is estimated that sea turtle numbers have declined considerably since the colonial period of the 16th century as a result of human activities, mainly the consumption of adult sea turtles and their eggs (Márquez, 2002).

Sea turtle populations are very sensitive to overexploitation because their life cycle is long and slow, often taking 10 or more years to reach maturity. In addition, their nesting habitats have deteriorated, as tourist complexes have been developed in coastal areas. Besides possible physical damage caused by beachgoers or domestic animals, these developments also involve artificial lighting that can particularly affect newly hatched turtles, which may become disoriented by the lights and move away from the sea instead of toward it. One of the greatest threats is undoubtedly accidental fishing, or bycatch, when turtles become trapped in nets and cannot return to the surface to breathe. As reptiles, sea turtles breathe through lungs, which means that after some time underwater they must return to the surface to take air.

Figure 7. Detail of the condition in which a hawksbill turtle was found after colliding with a boat. Image credits © Roatán Marine Park.

Although collisions with boats are less frequent threats compared with those mentioned above, they add to more recent problems such as plastic pollution and climate change, which threatens to eliminate males of the species (the sex of turtles is determined by nest temperature; Jensen et al., 2017). In several places around the world, boat collisions are considered an important and understudied threat to turtles (Denkinger et al., 2013).

Wright and collaborators (2020) found that boats did not appear to have a major effect on the behavior of hawksbill turtles in the Sandy Bay Marine Reserve in Roatán, but they highlighted the latent danger posed by boat collisions, especially as tourism in these areas has increased over the years. According to the management plan of the Bay Islands Marine National Park, vessels should not travel at speeds greater than 27 km/h in order to avoid collisions not only with turtles but also with other marine wildlife. In places such as the Galápagos Islands, where collisions with turtles have been identified as a problem, researchers emphasize strict spatial and temporal control of boat speeds, especially since turtles are more vulnerable to these accidents during reproductive seasons when they spend more time near the surface. In the Galápagos, researchers are studying the replacement of propellers with jet propulsion systems (Denkinger et al., 2013) and working with boat captains to determine how well humans can detect animals in the water while navigating (Parra Díaz and Loyola, 2021).

In Honduras, organizations such as BICA have already spent 30 years working to conserve sea turtles in the Bay Islands through nighttime patrols of nesting beaches (to prevent poaching and egg theft), recording important data to study the effects of climate change on nesting frequency and nest success, and conducting talks and environmental education programs that help raise awareness among the population about the importance of these animals for ecosystems and community well-being. If you are interested and want to know how you can support this institution through volunteering, do not hesitate to contact them.

Other measures you can take, especially during visits to coastal areas, include avoiding the consumption of any food or decorative products derived from turtles and making sure to dispose of garbage properly. Many coastal communities organize beach cleanups in which you can participate, and finally, in the rare case that you encounter an injured turtle or one that has come ashore to nest, you should know which organization to contact and report the event, always keeping a safe distance from the animal.

We thank BICA Utila for the important information provided for the preparation of this article, especially Ms. Ely Augustinus for her valuable time.

Follow us on social media:

Instagram: @Honduras_Neotropical

Facebook: @HondurasNeotropical

BICA Utila

Instagram: @bica.hn

Facebook: @bica.hon

Roatan Marine Park

Instagram: @officialroatanmarinepark

Facebook: @RoatanMP

By: Diego Ardon, Biologist

---

REFERENCES

Cruz GA, Espinal M, Meléndez O. 1987. Primer registro de anidamiento de la tortuga marina Chelonia agassizi en Punta Ratón, Honduras. Revista de Biología Tropical 35(2): 341-343.

Denkinger J, Parra M, Muñoz JP, Carrasco C, Murillo JC, Espinosa E, Rubianes F, Koch V. 2013. Are boat strikes a threat to sea turtles in the Galapagos Marine Reserve? Ocean and Coastal Management 80 (2013): 29-35.

Dodd CK. 1988. Synopsis of the Biological Data on the Loggerhead Sea Turtle. U.S.FishWildl.Serv.,Biol.Rep.88(14).

Dunbar SG, Salinas L, Baumbach DS. 2020. Marine Turtle Species of Pacific Honduras. Marine Turtle Newsletter 160:1-3.

Eckert KL. 2001. Status and distribution of the leatherback turtle, Dermochelys coriacea, in the Wider Caribbean Region. En: n: Eckert KL, Abreu Grobois FA (eds) Proceedings of the regional meeting: “Marine turtle conservation in the Wider Caribbean Region: a dialogue for effective regional management,” Santo Domingo, 16–18 noviembre 1999.

Eckert KL, Wallace BP, Frazier JG, Eckert SA, Pritchard PCH. 2012. Synopsis of the biological data on the leatherback sea turtle (Dermochelys coriacea). US Department of Interior, Fish and Wildlife Service, Washington DC.

Jensen MP, Allen CD, Eguchi T, Bell IP, LaCasella EL, Hilton WH, Hof CAM, Dutton PH. Environmental warming and feminization of one of the largest sea turtles populations in the world. Current Biology 28(1):154-159.

Márquez R. 2002. Las tortugas marinas y nuestro tiempo. Fondo de Cultura Económica, México.

McCranie JR, Harrison A, Orellana LV. 2017. Updated populations and habitat comments about the reptiles of the Swan Islands, Honduras. Bulletin of the Museum of Comparative Zoology 161(7): 265-284.

Parra Díaz M, Loyola D. 2021. Reducing the threat of boat strikes on Green turtles in Galapagos. Ingresado el 4 de abril de 2021 en https://www.darwinfoundation.org/en/research/projects/sea-turtles.

Wright MK, Baumbach DS, Collado N, Binte Safi S, Dunbar SG. 2020. Influence of boat traffic on distribution and behavior of juvenile hawksbills foraging in a marine protected area in Roatán, Honduras. Ocean and Coastal Management 198(2020): 105379.