Water Police will continue their desperate search for missing fisherman Trent Riley.

It’s believed the 26-year-old may have fallen off his tinnie near the Port of Brisbane on Wednesday afternoon.

Police hold grave concerns for his safety.

Search efforts will continue throughout the weekend into next week with the help of volunteer marine rescue organisations and search and rescue helicopters.

Water Police say while they appreciate members of the public efforts in conducting their own search for Trent, they are reminding people not to place themselves in any danger.

Friends and family are holding out hope he will be found alive.

His brother Shannon is calling on anyone in a position to help to join the search at 7am on Saturday.

“Trent is a survivor … we just have to keep our positive mindsets to get through this.”

The search will resume at first light Saturday.

Image: Nine News