Green sea turtle, Chelonia mydas (Life span & reproduction, respiration, salinity management, and survival threats)

Review: Abdel Rahman El Gamal (Founder of the website and video channel)

Life span and reproduction: green sea turtles seem to grow very slowly and usually reach sexual maturity at the age of 10 – 50 years with an average of about 25 years. Although green sea turtles live most of their lives in the ocean, adult females must migrate from feeding areas accompanied by males to the nesting grounds whereas nest making, mating and egg laying take place. The nests are between 3 to 5 times per season whereas a female lays her egg clutch which consists of about 100 leathery-skinned eggs in each nest before carefully cover the burrow with sand. The incubation period of green turtle eggs is about 60 days. Biologists believe that nesting female turtles return to the same beach where they were born. They may migrate hundreds of miles to the nesting beaches (grounds).

Respiration: during their active time, sea turtles swim to the surface every few minutes in order to breathe. However, adult turtles can remain underwater for more than 2 hours without breathing in resting time. This is attributed to the ability of turtles to withstand higher concentrations of carbon dioxide in their blood than most other air-breathing animals which able them to use their oxygen very efficiently. Similarly, muscles and blood of adult turkey are able to store oxygen in large quantities, allowing them to remain underwater for long periods of time. However, juvenile sea turtles do not enjoy this ability and hence they must sleep afloat at the water’s surface.

Salinity management: there are salt glands located behind each of the turtle’s eyes through which, tears of excess salt are shed from their bodies. Doing so, turtles get rid of accumulated salts from sea waters and hence maintain a healthy water and salt balance in their bodies.

Threats to green sea turtle’s survival: According to the IUCN Red List, the green sea turtle is classified as “Endangered”. The major factors that may contribute to survival of sea turtles could be summarized in:

Illegal harvest and hunting of turtle eggs for food, shells for jewelry making, skin for leather goods, meat for food, and fat for oil

Incidental catch of turtles in commercial shrimp trawlers (the use of turtle excluder devices (TEDs) could save trapped turtles

Marine debris when ingested by turtles by mistake. Plastics are common threat to sea turtles.

Habitat loss or degradation especially in coastal zones which may lead to the loss of nesting places or disturbed by noise, pollution, lights and other symptoms that may accompany human activities.

Predation especially by tiger sharks

Sources: Earth Justice and variety of records and publications



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