Authorities are investigating a dangerous breach of marine safety after two jet-skiers were spotted perilously close to a pod of dolphins off a popular Adelaide beach.

The incident, which occurred yesterday afternoon near Seacliff and Brighton beaches, has sparked concern and prompted an investigation by the Department of Environment and Water.

Video evidence captured by onlookers, which is expected to play a crucial role in the investigation, appears to show a young man on a jet-ski barrelling through a pod of dolphins while another hovers close by.

The Department of Environment and Water has described the incident as one of the most serious breaches in recent years.

“They were very close and interrupting where the dolphins were swimming and so that is in breach of the regulations,” spokesperson Lisien Loan said.

The incident has raised concerns about the potential disruption to the dolphin pod, which has been attracting significant attention from beachgoers in recent weeks.

“It changed their behaviour, they sort of all became a bit erratic and started moving away from the main pod,” local and dolphin behaviour expert Melissa Blewitt said.

Current regulations stipulate that jet-skis must maintain a distance of at least 300 metres from marine mammals, while riders who inadvertently find themselves within a pod must immediately switch off their engines.

Blewitt said there is a need for increased public awareness about responsible behaviour around marine life. 

“Just the education around how to behave around marine mammals, whether it be the dolphins out here, we’ve spotted whales out here as well,” she said. 

She also called for harsher penalties for those who violate marine safety regulations.

The Department of Environment and Water is working to identify the people involved, and has promised they will face the full force of the law once found. 

“So it’s up to $100,000 fine or two years in prison for interfering with a marine mammal and breaching some of those distances,” Loan said. 

The investigation is ongoing.