Here's the danger of releasing captive dolphins in the wild: they're now teaching wild dolphins how to "walk" with their tails along the surface of water!
WDCS researcher Dr Mike Bossley, who has observed Adelaide's Port River dolphins for the past 24 years, said he had documented spectacular tail walking in two adult female dolphins, known as Billie and Wave.
Now four other individuals have been recorded perfecting their walking techniques – Wave's calf Tallula, Bianca and her calf Hope, and calf Bubbles.
Tail walking is very rare in the wild and in thousands of hours of observation only one other dolphin has ever been observed tail walking in the Port River, and then only once.
The Port Adelaide dolphins are now said to be tail walking many times each day.
It is thought the mammals may have learned the remarkable skill from Billie – who spent a short period at a visitor attraction 22 years ago.
Dr Bossley said that the spread of tail walking appeared to be motivated by "fun", but it was also linked to a serious and fascinating cultural aspect previously unseen in the species.