The surgery performed on the sea lion "Sgt. Nevis" took about 30 minutes. The main goal was to cover two holes in his muzzle made by a single bullet. The bullet wound was visible on the front of the sea lion's face.
Dr. Praful Ramineni flew in from Washington D.C. to perform the surgery.
"I actually used a piece of his forehead and rotated it over, it's called a flap, to get that closed and plugged the hole," said Ramineni.
After the operation, Sgt. Nevis had his nasal passage fixed and the whole in his head fixed.
"He actually couldn't dive under water because when he went underneath, water would go in and usually sea lions actually seal their nasal cavity so they could go dive and not come up sputtering and coughing," said Ramineni.
Because Sgt. Nevis couldn't really dive for his food he had lost a lot of weight. Once he was rescued and brought to Six Flags Discovery Kingdom, he gained about 310 pounds.
"Now he's up to almost 700 pounds which is about average for a big male, a very healthy male, but of course he is being hand fed now so he's probably liking that a lot," said Lee Munro from Six Flags Discovery Kingdom.
Everyone who participated in the procedure did so for free. Dr. Bill Van Bonn is with the Marine Mammal Center in Sausalito.
"This animal was wronged by people and there is no doubt about that. He is a gunshot victim and that's just wrong. It's adverse human interaction," said Van Bonn.
Now Sgt. Nevis will be watched carefully by the staff at Six Flags Discovery Kingdom.
"And maybe in a couple of weeks or so he'll be back out on exhibit and back out with his girlfriends," said Munro.
That's when, once again, he'll assume the leading role.
A Sacramento-area fisherman will be back in court this month on charges shooting Sgt. Nevis. He was said to be tired of watching sea lions take his fish.