Man dies after jumping from Adelaide's Glenelg beach jetty

A man has died after jumping off the jetty at Adelaide's Glenelg beach.

Police and ambulance officers were called after the man did not resurface when he jumped into the water about 8:00am (ACDT) today.

Surf Life Saving South Australia's Shane Daw said after a five to 10-minute search near the jetty, the man was brought to shore.

The man was believed to be aged in his forties.

"We believe the gentleman was fishing off the jetty and he's jumped off - whether to go for a swim or other reasons, we're not sure so the police are certainly looking into that," Mr Daw said.

"We've had reports that he was swimming and then he just seemed to disappear below the surface of the water, and other than that we don't have many other details to go on."

Mr Daw said 12 to 15 surf lifesavers were out performing the search along with water police and police on shore.

With the assistance of a member of the public on a paddle board his body was recovered.

Police and ambulance crews attempted CPR, but he was unable to be revived.

Mr Daw warned beach-goers to be careful in the water as the warm weather approaches.

"We know it can be exhilarating and we know it can be fun, but what we really want people to be aware of is there also are inherent risks with jetty jumping in particular," he said.

"The conditions can change, it can get quite shallow, there can be objects under the water so you can actually hurt yourself when you do jump in.

"We don't want to be the fun police on it, but what we are asking people is if they are going to do that sort of activity, understand their own skills, understand their own limitations and also understand the environment they are jumping into."