Green vs Hawksbill Sea Turtle? Here's How You Can Tell the Difference Between the Most Encountered Sea Turtles in the Virgin Islands!

While snorkeling in the waters in the Virgin Islands, there are two types of sea turtles that are commonly encountered. The most common sea turtle that snorkelers see is the green sea turtle. Green sea turtles got their name not from how they look on the outside, but rather from how they look on the inside. Green sea turtles are herbivores and the chlorophyll from the sea grass that they eat turns their body fat green! Green sea turtles spend most of their time in shallow, near shore sea grass flats.

The second species of sea turtle that is found in the Virgin Islands is the hawksbill sea turtle. Hawksbill sea turtles got their name from the pointed beak that allows them to get into small holes and crevices in the coral reefs since their diet consists primarily of sponges.

Here is table highlighting the differences between green vs hawksbill sea turtles.

	Green Sea Turtle	Hawksbill Sea Turtle
Quick Facts	Scientific name: Chelonia mydas Weight: 300-400 pounds Length: 3-4 feet Lifespan: estimated 70 years Reach maturity at 25-35 years Diet: sea grass and algae Conservation status: Threatened	Eretmochelys imbricata Weight: 100-150 pounds Length: 2-3 feet Lifespan: estimated 50-60 years Reach maturity: 20-35 years Diet: sponges Conservation status: Endangered
Shell Shape and Color	Larger, more rounded shell Olive to dark green color, smooth shell	Narrow, pointed shell with overlapping scutes Mottled brown and gold with a unique, intricate pattern
Head Shape	Large, somewhat rounded head	Narrow, pointed head (resembles a hawk’s beak)
Scutes on Face	1 pair of scutes between eyes	2 pairs of scutes between eyes
Behavior and Habitat	Seagrass beds, shallow coastal waters	Coral reefs
Nesting	Nest every 2-4 years 80-120 eggs/nest 2-5 nests/season Eggs the size of a ping-pong ball	Nest every 2-4 years 130-160 eggs/nest 2-5 nests/season

Sea turtles, like all reptiles, breathe air, which means that the turtles must swim to the surface to breathe. While they are active and foraging during the day, most turtles will come up to breathe every 5-15 minutes but can hold their breath for 4-7 hours while resting. Please give the sea turtles space and don’t approach them when they come up for air, not only is that illegal, but it also causes stress to the turtles. The green sea turtles at some of the busier beaches are fairly desensitized to human presence, so if you just float very still while snorkeling, they will often surface near you, and if you remain still, they will take several needed breaths before heading back to the seafloor to eat.

Threats and ways that we can help

Only about 1 in 1,000 to 1 in 10,000 sea turtle hatchlings survive it to adulthood. There are many threats to sea turtles.

Light pollution: As hatchlings, the baby sea turtles head to the brightest light around, which for about 110 million years (before the invention of electricity) was moon and star light reflecting off the surface of the ocean. Artificial light from humans can cause hatchlings to head inland rather than to the sea, where they can become trapped by things like curbs in parking lots. 

If you live in an area where sea turtles are nesting, make sure to close your window shades at night to prevent the turtles from heading the wrong way. You can also volunteer with a turtle program in your area to help survey beaches for nests, mark them, and help with nest excavation after hatching to make sure that any left behind get a chance to make it to the sea.

Bycatch in fishing gear: Sea turtles can become entangled in nets, swallow fishhooks, get entangled in monofilament fishing line, and drown in shrimp trawls.

As a fisher, be mindful that monofilament scraps don’t end up in the ocean. Shrimp trawlers have installed Turtle Exclusion Devices (TEDs) in their nets, which are essentially a large metal grate that allows the shrimp to pass into the tip of the net, but when the large turtle hits the metal grate, it opens a trap door for them to escape.

Schematic of a shrimp net with a Turtle Excluder Device (TED) showing how turtles can escape

Climate change: For many reptiles, including sea turtles, the temperature of the nest determines if the egg will become a male or female turtle! This is called temperature-dependent sex determination and for sea turtles, when the nest temperature is above 89°F, the eggs will be female and when it’s below 82°F, the eggs will become males. For nests that have temperatures that fluctuate, you will get a mix of males and females. A fun way to remember this is:

Hot chicks and cool guys!

As beaches get warmer and warmer, there will be fewer and fewer males. The higher sand temperatures can be lethal to eggs and/or alter the ratio of male and female hatchlings. Additionally, warmer climates lead to stronger and more frequent storms, which can inundate a nest and wash away large portions of the beach.

We can try to reduce our carbon footprint. Reduce, reuse, recycle.

Poaching: People still harvest turtles for food, for jewelry, and the eggs are thought to be an aphrodisiac.

We can educate people to try to protect these species and hire enforcement to patrol beaches.

Disease: A disease called fibropapillomatosis causes external and internal tumors in green sea turtles. Tumors near the eyes obstruct their vision, near the mouth makes feeding difficult, and on appendages restricts mobility.

A turtle hospital in the Florida Keys can perform surgery to remove the tumors. We can try to make habitats healthier through protection.

Loss of habitat: Female turtles return to the beach where they hatched to nest and since it takes at least 25 years for a turtle to reach maturity, unfortunately, quite often much of the beach has been lost to human habitation.

We can set aside tracts of land that are important to sea turtles, making them parks or sanctuaries, which will benefit many species and preserve a bit of nature for future generations of people.

Pollution: Sea turtles will eat jellyfish and a plastic bag floating in the water looks very similar to a jellyfish. When a turtle accidentally ingests plastic, it can become lodged in their intestinal tract and can cause the turtle to starve to death.

We can participate in beach clean-ups to help remove pollution from the water and we can cut down the amount of trash that we produce by reducing, reusing, and recycling. Use a refillable water bottle rather than many plastic bottles. Please don’t release balloons into the environment.

Vessel strikes: In areas where boats and sea turtles coincide, occasionally sea turtles get hit by boats.

Boat operators can drive slower and keep an eye out for turtles. Report any injured sea turtles to Sea Turtle Assistance and Rescue (STAR) Network in the USVI.

Sea Turtle Assistance and Rescue

340-690-0474

All photos courtesy of Sara and Lee Richter