A shocking find turned a regular fishing trip into a horrible experience for local fisherman Andrew Hallett and nephew Phillip.
The pair discovered a small dead dolphin floating on the water's surface near the OneSteel rock wall on Saturday afternoon at 2pm.
Environment and heritage conservation investigator Nick Bailey arrived in Whyalla on Tuesday to take the now frozen dolphin back to Port Augusta and eventually the Maritime Museum in Adelaide following the autopsy.
Mr Bailey confirmed that the dolphin was about a week old, had been dead about two days, and had died of unnatural causes.
"Any unnatural marine mammal death is of concern," Mr Bailey said.
Mr Hallett believed that it is likely the dead dolphin drifted in from south of the discovery area.
A dolphin lover all his life, Mr Hallett and his family were devastated by the find.
"It nearly bought tears to my eyes," Mr Hallett said.
"It felt like someone losing their own little one, it just puts a big lump in your throat."
Mr Hallett said that the dolphin effected everybody around him that knew about it.
"My two oldest kids, they're two and five both cried, they were quite upset," Mr Hallett said.
The find happened while the pair were ready to do their regular round of fishing.
After spotting something floating on the surface nearby, Phillip alerted Andrew and as they neared it, Andrew's worst fears were confirmed.
Andrew immediately contacted his wife who corresponded between Andrew and the Parks and Wildlife department, where he took instructions on what to do with the dolphin and how to retrieve it.
He then brought the dolphin straight back to shore, where it was wrapped in about 10 garbage bags, and frozen in one of Andrew's freezers until environment and heritage retrieved it.
Mr Hallett described the experience as one of the lowest feelings he has ever had, especially after witnessing the birth of a dolphin in the Whyalla marina in December.
"It was one of the best things I have ever seen," Mr Hallett said.
"But after seeing that and then finding the dead one, it takes a lot of that feeling away."
Still travelling out for his regular spot of fishing, Mr Hallett wants to make the public aware of cruelty to dolphins and to watch out for any suspicious activity, which has affected him deeply.
"I've seen people actually belting them with poles to get away from their boat," Mr Hallett said.
"Every time I go out, I'm always watching, I'm expecting to find things."
Autopsy results are expected to be done within a month.