Category: About the Species

Sea Turtle Populations

Keep it in mind that the total population of sea turtles is unknown. All the numbers given are approximated and present some ambiguity because of the turtle movements. The fact that male turtles and juvenile sea turtles do not come to shore makes it impossible to determine the actual number.

Additionally, there are different trends in how the female species nest. Some will nest more than once on the same beach in a given season, and others will visit several beaches during the nesting season. When these factors are paired with the varying nesting frequency, counting becomes very difficult.

Before we continue, let me thanks to the guys a Painters Sunshine Coast for their limitless help and their unconditional support of the sea turtle preservation.

Sea turtles are among the endangered marine life, and in the past two centuries, they have suffered human activities. They are tasty snacks for humans, and every part is equally useful to man; therefore, scaling up poaching and over-exploitation. These mariners also suffer from bycatch (Accidental capture) and habitat destruction.

Marine surveys recently estimate the total sea turtles to be around 6.5 million. Every species carries a different number, which depends on how it is endangered. Here are different species approximates based on some criteria.

  • Kemp’s Ridley: This is the most endangered sea turtle. In 1942, the nesting ridleys were about 42,000, and the number dropped drastically to 1,429 in 1995 nesting season. Strict protection measures were put in place, and they have been fruitful. The current estimated population of Kemp’s Ridley is 9000 adult females.
  • Green turtles: Researches show that green sea turtles dropped by approximately 60% in the past 120 years. The largest nesting hotspot is Tortuguero, Costa Rica, and it receives around 22,500 green turtles every nesting season. Raine Island coastal reef has the second largest population of around 18,000 nesting females annually. The green sea turtles population ranges from 85,000 to 90,000 adult females.
  • Hawksbill turtles: Being solitary nester and the fact that their track doesn’t last in the sand makes it difficult to estimate the population. Stable populations are found in Australia’s Great Barrie Reef, Oman, and the Red Sea. Hawksbill’s current population is estimated at 57,000 adult females nesting in different regions.
  • Loggerhead turtles: Nesting populations of loggerheads have been declining over the past years. The largest nesting areas are Oman and Masirah Island receiving 30,000 and 20,000 nesting females per season, respectively. Although the total population is unknown, the US loggerhead estimates are at 90,000 nesting females.
  • Leatherback turtle: The population of this sea champion has been declining dramatically along the pacific coasts. However, the Florida coastal regions have been recording incredible leatherback nesting recently. The estimate of nesting females ranges from 34,000 to 36,000 in every season.
  • Flatback sea turtles: Approximately 25,000 to 30,000 come ashore of Australian waters to lay eggs. It represents the most vulnerable species of sea turtles due to its limited distribution.
  • Olive Ridley: This is the most abundant sea turtle species. Even though nesting Olive Ridley has declined along coastal regions adjacent to the northwestern Atlantic, they strike higher numbers. On average, there are about 2 million nesting females that visit the coastal lines.

The listing of sea turtles under the Endangered Species Act has resulted in significant fruits. Make sure to embrace the conservation of these charismatic reptiles.

Species of the Sea Turtles

Seven sea turtles species have been gracing marine water over millions of years. Turtles are super-charismatic animals that like spending their entire life in the deep waters. However, they periodically migrate to show to lay eggs or bask.

Six species out of the seven are known to live in US waters while the flatback turtle is found along with Australia’s coastal areas. Here are the seven sea turtle species

Leatherback (Dermochelys coriecea)

The leatherback is the “big boy” of sea turtles. Apart from being the biggest sea turtle, it is also one of the largest (fourth) reptiles ever. This species grows largest, and its weight ranges between 500 to 2000 pounds. On average, leatherback adults measure 5 to 8 feet (1.5-2.4 meters).

The species is said to have a large appetite and can travel several miles in search of food. For instance, an adult female tracked by satellite telemetry traveled 12,000 miles. Because of their thermoregulatory adaptations, they dive deepest of all species, up to 4,000 feet. The population is dropping drastically due to human poaching.

Green turtle (Chelonia mydas)

It makes one of the most endangered species. At adulthood, these turtles are herbivores and feed on algae, seaweeds, and sea grasses. Green turtles can grow up to four and one-half feet in length and weighs 400 pounds. It is believed that their green label comes from the pigment of diet colors.

Like the leatherback, green turtles are deep divers and can stay underwater for 5 hours. The population has been dropping in the past century due to the harvesting of their eggs and peaching due to their healthy meat.

Loggerhead (Caretta caretta)

Loggerhead is often seen due to its highly notable large head. They also love sandy beaches and staying along seashores. This species is common in tropical and temperate shorelines of the Pacific, Atlantic, Indian, and oceans.

The species has a heart-like shape, grows up to 4 feet long, and can weigh anywhere between 200 and 400 pounds. Loggerhead are not ready for mating until the age of 33. 

Hawksbill (Eretmochelys imbricata) 

You can easily identify hawksbill turtle from the other species because of its shell, which resembles the heart shape. It is characterized by colorful shells, sharp bird-like beaks, and a narrow head.  

Hawksbills are known to reach coral reef crevices as they hunt for food. They grow up to 3 feet extended long and averagely weighs 200 pounds. Averagely, they lay approximately 140 eggs per nest and usually nest four times in every season.

Kemp’s Ridley (Lepidochelys kempii) 

Kemp’s Ridley was at the brick of depleting due to high demand. It is the smallest of all turtle species and grows up to 2 feet. On average, these turtles weigh 100 pounds.

Kemp’s Ridleys are grey and green and primarily reside in Mediterranean waters with Rancho Nuevo, Mexico being the main nesting grounds. They are ready for mating within 10 to 15 years of age.

Olive Ridley (Lepidochelys olivacea)

It ranks second smallest above the Kemp’s Ridley. On average, this species grows up to two and one-half feet in length and weighs around 100 pounds. Crustaceans and jellyfish make their primary food; however, they can feed on algae if there is no other option.

Olive Ridleys are pale green and make the highest population of turtle species. They start mating around 15 years and can lay up to 100 eggs per nest.

Flatback (Notator depressa)

The species is named after its flat carapace, which is not curved like the other sea turtle shells. Its shell is pale greying-green with upturned outer margins. Unlike other turtle species spread all over, this species is found in Australia’s coastal coral reefs. Flatback turtles weigh approximately 200 pounds and grow up to 3 feet long.