A female Hawaiian monk seal thought to have swallowed a fish hook and brought to O'ahu from Kaua'i for possible surgery didn't need the operation after all.

Veterinarian Bob Braun perform an endoscopic procedure yesterday morning at Marine Corps Base Hawai'i and found no signs of a fish hook, said Wende Goo, spokeswoman for the National Oceanic and Atmospheric Administration.

The seal was first spotted May 26 with a fishing line trailing out of her mouth and then again on June 14. At that time researchers from NOAA Fisheries attached a satellite transmitter to help locate her at a later date when rescue efforts were in place.

On Tuesday, she turned up on Palama's Beach, where she was captured and transported to Honolulu by a Coast Guard C-130 patrol plane.

The untagged seal was estimated to be 4 to 5 years old, but little is known about her, Goo said.

The possible surgery had been scheduled for yesterday at the Marine Mammal Research Laboratory of the Hawai'i Institute of Marine Biology.

The seal was transferred yesterday to the Waikiki Aquarium to rest and for further blood work. If she gets a clean bill of health, she will be transported back to Kaua'i this afternoon, Goo said.

"It's good news because the seal didn't have to go through that trauma," Goo said, adding that she will be returned to the area where she was captured.