The waste could not be removed by the volunteers as they did not have the resources needed to deal with it, Mr Jhinku said.
However, the pile was reported to the Dunedin City Council.
Mr Jhinku also attended the EnviroSchools Cleanup on the beach near the Otago Yacht Club in Magnet St on Sunday morning.
Household waste was also discovered there, left in a similar fashion to the rubbish found near John Wilson Ocean Dr.
Despite the illegal dumping, Mr Jhinku said, the cleanups were successful and were a great way to start Sea Week.
The John Wilson Ocean Dr cleanup also featured a demonstration of Marine Metre Squared, a new coastal monitoring project pioneered by the University of Otago.
Dunedin City Council solid waste manager Ian Featherston said he was aware of the dumping and a council contractor had been dispatched to clean it up.
He hoped the contractor would have searched through the waste for identifying details in order to fine the perpetrator.
He was not aware of an increase in illegal dumping around the city.
''It's just something that gets spread around the city and pops up from time to time,'' he said.