Members of the public had heard shouts for help and a whistle.
Several search parties were sent out to cover nearby areas.
The fire service also assisted by sending up a drone using thermal imaging to search the area.
Nothing was found, however, so the decision was finally made to stand down.
An OMRT spokesperson said: "Thanks to all the emergency services involved, including GMP, North West Ambulance Service and Greater Manchester Fire and Rescue Service.
"It was another great example of multi-agency cooperation."
Fifteen OMRT personnel were involved for approximately three hours.
