generalised marine turtle life cycle overview

  1. About 60 days after the eggs are laid the sea turtle hatchlings free themselves from their underground nest. In a joint effort they dig themselves out of the nest and usually emerge from the nest in the evening or night hours. Orientating themselves towards the brightest horizon they set out for the ocean. On the short journey to the water they have to face numerous obstacles and dangers, such as artificial lights distracting them, beach furniture blocking the way, holes and sand castle becoming lethal traps, predators looking for a snack and people disturbing or even crushing them.
  2. As soon as the tiny marine turtle hatchlings enter the water, they swim out to the open ocean. Here they are caught in currents and seaweed.
  3. The hatchlings / juvenile sea turtles spend their first 5 to 10 years drifting and actively swimming in the open ocean currents, feeding on plankton near the surface and growing. This time is called “the lost years”.
  4. At the age of 5 to 10 years the young sea turtles move from the open ocean to coastal waters.
  5. The sea turtles stay in the coastal feeding areas for the rest of their lives, except for their breeding migrations. Between 20 and 50 years of age sea turtles become sexually mature and undertake the first of many breeding migrations, usually back to the area where they hatched decades ago.
  6. During their breeding migration sea turtles may swim over 3000 km, but most migrate less than 1000 km to breed. Females undertake the breeding migration every two to six years depending on favorable environmental conditions.
  7. Mating occurs in breeding aggregations at sea near the nesting beaches. Females may mate with different males.
  8. As soon as a female sea turtle is ready to nest, she sets off to the beach (usually the beach where she hatched). After emerging from the water, she crawls up the beach looking for a suitable nesting place. When she found a good spot for her nest on a dry part of the beach, she prepares her nest and lays a clutch of between 40 and 130 eggs. After closing the nest and disguising it, mama sea turtles returns to the sea to rest. She usually returns two to four times during a breeding season in a two-week interval to lay more eggs. For detailed information about the nesting read here.
  9. At the end of the breeding season, the marine turtles return to their feeding areas.