Protecting the Port River dolphins

In late 1987 a photograph appeared in the Adelaide Advertiser. It showed a young dolphin and a horse swimming together in the gray light of early dawn.  The photo attracted Dr Mike Bossley's interest and initiated a 34 year study of the local dolphins which continues to this day.

The dolphin in the photo became known as Billie and her story encapsulates in many ways the story of these highly urbanized dolphins.  Billie was an orphan when first encountered in 1987 but the fate of her mother is unknown.  In the twenty five years of her life she experienced being trapped behind a lock, held in captivity and had five of her seven calves die in infancy.  One of her surviving calves became trapped in an industrial sump and was only rescued by a lucky accident.  We don’t know why so many of Billie’s calves have died but suspect the polluted waters which she called  played their part.

While in captivity, Billie apparently learned how to “tail walk” by observing the trained dolphins. After her release from captivity she returned to the Port River and began tail walking there. For many years she was the only dolphin to perform this behaviour but in the next few years other dolphins were obvserved tail walking as well in what seems to be an example of animal cultural behaviour (behaviour passed from generation to generation by learning). Sadly, Billie died well before her time in 2009, the victim of kidney failure, but even today, some dolphins in the population continue to tail walk.