Sea turtles are the only reptiles that live in the Adriatic Sea. As well as land turtles, they belong to the ancient order Chelonia.
All of the sea turtles breed on sandy beaches. 150 up 200 eggs are laid in holes dug in sand. As sand beaches have been popular destinations for humans, disturbing the turtles while laying the eggs and furthermore destroying them as well as the hatches left catastrophic consequences for sea turtle population all over the world.
Turtles often find themselves entangled in fishing nets. Since turtles are air-breathing reptiles, they must surface at regular intervals to refill their lungs with fresh air. Although, in normal conditions,  they can spend long periods of time underwater, when they get entangled in a fishing net, due to stress they drown.
Turtles are also endangered by motor boats, commercial exploitation of their meat, eggs and shells, and naturally sea pollution.
Due to the strong negative anthropogenic influence number of populations of all sea turtles has dropped so they have been strictly protected by Croatian regulations and international conventions (Environmental Protection Act NN 30/94, Regulations on the protection of certain reptiles (Reptilia) NN 47/95). Three species of sea turtles can be found in the Adriatic, although in scarce numbers.
The leatherback turtle (Dermochelys coriacea)
The Leatherback Turtle lives mostly in  tropical and subtropical oceans, and is very rare in the Adriatic and Mediterranean. It can reach a length of over 2 m (2.7 m) and weight of 350 kg (900 kg). What distinguishes it from other turtles is its shell which is leathery, with bony mosaic, rather than hard and compact shell. Its body is dark brown with bright spots. It feeds mostly on salpas and jellyfish, as well as other aquatic animals and plants.
Pursuant to the Rule Book on Compensation Fees for Damage Caused by Unlawful Actions on Protected Animal Species (NN 84/96), penalty for killing a Dermochelys coriacea is a HRK 40,000 fine.
The loggerhead sea turtle (Caretta caretta)
The Loggerhead Sea Turtle also lives mostly in tropical and subtropical oceans. It feeds on echinoderms, sponges, mollusks, crustaceans and can reach one meter in length. Body colour varies in between brown and brownish – red.
The Adriatic population is part of the population which breeds in Greece. It is presumed that rarely and in exceptional occasions they hatch eggs on sand beaches of some southern Dalmatian islands.
It is estimated that around 2500 Loggerhead Sea Turtles are caught annually for commercial purposes. If it is considered that all of the  Mediterranean population is estimated at 5000 adult loggerheads, it is clearly visible how catastrophic the consequences are for the species.
Pursuant to the Rule Book on Compensation Fees for Damage Caused by Unlawful Actions on Protected Animal Species (NN 84/96), penalty for killing a Caretta caretta is a HRK 35,000 fine.
Green sea turtle (Chelonia mydas)
The Green Sea Turtle lives mostly in tropical and subtropical oceans, and is very rare in the Adriatic and Mediterranean. It feeds almost exclusively on various species of sea grasses and seaweed, while juveniles are known to subsist on marine invertebrates. The green sea turtle is known to grow up to one and a half meters long. Colour varies from grey – brown to olive green, hence the name. As well as The Loggerhead Sea Turtle,the Green sea turtle is often targeted by poachers.
Pursuant to the Rule Book on Compensation Fees for Damage Caused by Unlawful Actions on Protected Animal Species (NN 84/96), penalty for killing a Chelonia mydas is a HRK 40,000 fine.