This is the heartwarming moment fishermen release 30 endangered manta rays stuck in a fishing trawler net in southern Thailand.

The seamen were on their evening shift sailing the western edge of Phuket island on July 10 when they came across the marine animals splashing around frantically in their catch.

Footage recorded by the ship's captain shows his colleagues helping an estimated 30 manta rays caught in the net.

In the video, the fishermen jumped into the sea and released the tension in the net so that the marine animals could be freed

Bird said that this is not the first time they encountered marine creatures getting entangled in their nets but they always free them.

He said: "We would not harm any protected species, we will only take the fish that we are supposed to catch."

Manta rays are classed as 'vulnerable' on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

They are threatened by pollution, entanglement in fishing nets, and illegal fishing for their gill rakers which are used in Chinese medicine.