Around 4,000 leatherback sea turtles (Dermochelys coriacea) are rescued each year in Costa Rica from their nests that are threatened by floods or human movement through the nursery in Las Baulas Marine Park, on the country's northern Pacific coast. The eggs are protected until the turtles hatch and begin their journey across the beach to the sea.

Costa Rica has the largest leatherback turtle population of the eastern Pacific. However, a decade ago some 2,000 turtles laid eggs in this protected area, but today just 60 to 70 do so.

The decline is due to human activities, such as egg stealing, the use of long-line fishing nets, water contamination and to climate change, says Marco Solano, secretary-general of the Inter-American Convention for the Protection and Conservation of Sea Turtles.

The leatherback can reach a weight of 500 kilos and a length of two meters. It dives to great ocean depths and its shell is soft and flexible like leather.