The South Australian Environment Protection Authority (EPA) and SA Health are investigating a sewage spill in Port Lincoln yesterday.
It is believed 26 tonnes of waste from a moored bulk carrier was discharged, with the EPA saying beaches west of Kirton Point Jetty were likely impacted.
City of Port Lincoln Council closed public beaches from Shelly Beach to Kirton Point this morning, with water sample tests being carried out today.
Council's chief executive Matthew Morgan said, while there were no visible signs of sewage in the ocean this morning, council was concerned with remnant waste from the spillage.
"We don't want people on the sand and on the water and we don't want people fishing; we're happy to keep the jetty open at this stage, but we don't want people fishing off the jetty," he said.
"We've got teams putting up signs and we'll be in communication with SA Health and the EPA.
"They're doing some water samples in those areas, and we should know [the results of] those either later today or early tomorrow."
Swimmers and fishers warned
Yesterday, temperatures in Port Lincoln reached more than 30 degrees Celsius with many families swimming at the main beach near the wharf.
Mr Morgan said residents who went swimming yesterday should monitor their health, and if there were any concerns they should ring their GP or SA Health.
"At this point it's probably not a cause to panic too much until we get more information from the EPA," he said.
Mr Morgan also advised any fishers who caught seafood around Port Lincoln beaches yesterday not eat anything that was caught.
Jamie Coote was fishing off the Port Lincoln wharf yesterday and noticed the spillage around 3:45pm.
"There was nothing there to start with, then I saw a big dark patch off the end of the wharf — I thought it was a school of fish," he said.
"We fished there for a couple of hours because we had no idea."
Mr Coote said he saw six boys jetty jumping near the spillage area as well.
"It's not just the water side of it, it's also how many contaminants there are," he said.
"If it's a freshwater product it's going to be floating [towards] surfaces — pylons, rocks, the breakwall. It's not going to sink in one area."
