Conservation

Underwater Ambassadors

Turtles

 

Turtles

Stars of the Sea

Anemones

Shysharks

Seals

Turtles

Sea turtles are reptiles and very well suited to life in the ocean. They live and travel in almost every ocean basin throughout the world, and the females nest on tropical and sub-tropical beaches. The migrate long distances to feed and mate, often crossing an ocean.

Sea turtles, along with other turtles and tortoises, are part of the order Testudines. All species except the leatherback sea turtle are in the family Cheloniidae (Chel·​o·​ni·​i·​dae).

The leatherback sea turtle is the only extant member of the family Dermochelyidae (Der·mochelyi·dae). They are among the oldest creatures on Earth and still looks very similar to 110 million years ago.

Species & IUCN status

All sea turtles appear on the IUCN Red List of Threatened Species.

There are seven species of sea turtle, of which five species visit South African waters, and two species, Loggerheads and Leatherbacks, nest along our coast line:

Loggerhead Sea Turtles

(Caretta caretta) IUCN Vulnerable (nesting in KwaZulu-Natal)

Most of our turtle patients are loggerheads – named for their exceptionally large heads.The Loggerhead turtle is the world’s largest hard-shelled turtle.

Range

Loggerhead turtles have a cosmopolitan distribution and are thus found worldwide, nesting over the broadest geographical range of any sea turtle. They are found in the Atlantic, Pacific and Indian ocean, as well as the Mediterranean sea. 

Habitat

Their habitat preference depends quite heavily on life stage, with the junvenile turtle preferring sheltered shallower bays, non-breeding sub-adults and adults are more oceanic, and breeding adults spend more time along the coast near breeding sites. They rarely come ashore besides when females nest. Loggerheads occupy water with surface temperatures ranging from 13°C – 28°C during non-breeding season. Temperatures from 27°C – 28°C are most suitable to nesting females.

Diet

Loggerheads are omnivorous and has the longest list of known prey items compared to any of the other sea turtle species. They enjoy gastropods (sea snails), bivalves (mussels), sea sponges, corals, sea anemones, barnacles, isopods, sea urchins and sea stars, fish, jellyfish, squid and blue bottles.

Physical Characteristics

Loggerheads have heart-shaped carapaces (top shells), with an adult weight range of 80 – 200kg. The largest loggerhead ever recorded weighed 545kg.

The head and carapace range from a light yellow to orange-brown colour, while the plastron (under shell) is usually very light of colour. The carapace is divided into plates called scutes.

The shell serves as great protection, but unlike tortoises, sea turtles cannot retract their heads or flippers into their shells. They have powerful jaws which are used to crush prey. The Loggerhead’s sex is determined by the temperature of the underground nest. At a temperature of 28°C the hatchlings will be male, and females will emerge from eggs incubated at 32°C. At about 30°C there will be equal chance of males and females developing in the eggs.

Turtles can swim very long distances, and when migrating, can travel 1.6 km.h-1. The most famous turtle in the world, the Loggerhead female called Yoshi, has travelled 40 000 km since her release from the Two Oceans Aquarium.

Scientific name

Caretta caretta

 

Conservation status

IUCN Vulnerable

Spotlight on Scientist

Talitha Noble – Conservation

Coordinator and Turtle Hero. Talitha Noble is our conservation coordinator and leading our turtle rescue, rehabilitation and release work. She is a qualified marine biologist and passionate about the ocean and sharing her experiences to inspire all to love the ocean and to care about it. Sea Turtles are fantastic ocean ambassadors and Talitha has gained incredible experience caring for sick and injured sea turtles and getting them healthy again and ready for release.

Leatherback Sea Turtles

(Dermochelys coriacea

Leatherback turtles also breed along the South African coast in northern KwaZulu Natal, and we generally see very few of them. The number of nesting females is still quite low, and they are also a lot more challenging to rehabilitate. The Leatherback is the largest sea turtle of all living turtles. It is easy to distinguish as it does not have a bony shell, but its carapace is covered with a thick leathery skin and oily flesh.

Range

Leatherback turtles also have a cosmopolitan range and has the widest distribution of all turtle species. It is found in tropical and subtropical ocean areas and extends well into the Arctic circle.

Leatherback turtles are found primarily in the open ocean. They tend to prefer deeper water in the day time, and shallower water at night, when they follow their prey, jellyfish, at night.

They are known to dive deeper than 1000m and they seem to avoid areas with shallow coral beds.

Habitat

Their habitat preference depends quite heavily on life stage, with the junvenile turtle preferring sheltered shallower bays, non-breeding sub-adults and adults are more oceanic, and breeding adults spend more time along the coast near breeding sites. They rarely come ashore besides when females nest. Loggerheads occupy water with surface temperatures ranging from 13°C – 28°C during non-breeding season. Temperatures from 27°C – 28°C are most suitable to nesting females.

Diet

Leatherback diet consist almost entirely of jellyfish, and they are also seen as an important species, just as sunfish, to control jellyfish blooms. They also feed on other soft-bodied organisms such as tunicates and squid.

They are particularly prone to ingesting plastic, which is a major threat to their health and survival.

Physical Characteristics

Leatherbacks are known as one of the fastest moving reptiles and they hardly ever stop moving. This contributes to their bodies and muscles generating additional heat, and therefore their ability to withstand cold water.

Leatherbacks have a very hydrodynamic body design with a tear-dropped shaped shell. They have very large front flippers adapted well to swimming long distances.
Leatherbacks have a weight range between 250kg and 700kg.
They present various characteristics, such as a fat layer, to adapt to cold water.

Scientific name

Dermochelys coriacea

 

Conservation status

IUCN Vulnerable

Spotlight on Scientist

Inge Adams – Research

Coordinator and Turtle Hero. Inge is a marine scientist with a keen interest in animal health and assisting Talitha in our sea turtle hospital. Inge did her Master’s thesis on dolphin parasites and has built up a lot of experience and skill in animal health management. Inge plays a critical role in our turtle rehabilitation unit, ensuring optimal care to get our patients strong and healthy for release.

Bob

Bob is a green turtle and arrived at the Two Oceans Aquarium after being rescued by Jeffrey Slater at De Hoop nature reserve. Bob was in a terrible condition with a fractured plastron, serious neurological and ophthalmic infections and suffered from plastic ingestion.

After intensive care and assisted feeding, Bob passed a number of plastic bags and balloons!

With ongoing care he has regained his eye sight, which was seriously impacted on by the infections and he has gained a lot of strength. He has not been cleared for release due to some persistent neurological challenges. However, the team continuously work on therapeutic activities for Bob to get him release safe and ready. He absolutely loves his vegetables (Green turtles are vegetarian as adults), and enjoys nothing more than a good old back scratch. Bob’s story has inspired thousands of people to say no to balloons and reduce the use of single use plastics.

Yoshi

Yoshi is a Loggerhead sea turtle, and the most famous sea turtle in the world. She was rescued by a Japanese fishing vessel and brought to the Aquarium to be cared for. She spent 20 years at the Aquarium, which as a very safe environment for her to grow to an impressive 183 kg. It took 18 months of preparations and training to get her ready for release, and in December 2017, she returned to the open ocean.

She initially traveled up the west coast of Africa, after which she turned around, passed Cape Town and head straight across the Indian ocean. This was the first recorded movement of a Loggerhead turtle between Africa and Australia. She is still enjoying the Australian coast, and has already traveled 40 000km since her release. What a remarkable journey.

Spotlight on Scientist

Maryke Musson – CEO

Maryke is absolutely passionate about the ocean and people. She is a marine scientist and medical physiologist and was part of the initial team of aquarists when the Two Oceans Aquarium opened in 1995. She then shifted her focus to marine research and aquaculture development for many years, with local and international involvement. She returned to the Aquarium in 2015 and was the driving force behind Yoshi’s release and loves nothing more than assisting the turtle team hands-on with rehabilitation work.

Green

Scientific name

Chelonia mydas

 

Conservation status

IUCN Endangered
(frequently seen in South African waters)

Hawksbill

Scientific name

Eretmochelys imbricate

 

Conservation status

IUCN Critically Endangered
(seen in South African waters)

Olive Ridley

Scientific name

Lepidochelys olivacea

 

Conservation status

IUCN Endangered
(seen in South African waters)

Loggerhead

Scientific name

Caretta caretta

 

Conservation status

IUCN Endangered
(frequently seen in South African waters)

Kemp’s Ridley

Scientific name

Lepidochelys kempii

 

Conservation status

IUCN Critically Endangered
(do not visit South African coastline)

Flatback

Scientific name

Natator depressus

 

Conservation status

IUCN Data Deficient
(do not visit South African coastline)