By Charlie De Mar

CHICAGO (CBS)–A kayaker out fishing for salmon on Lake Michigan Monday found something much larger than he anticipated–a four-foot long American alligator.

Fisherman David Castaneda was out on the water near Waukegan Harbor around 9:30 a.m. when a floating object caught his attention.

As he paddled closer, his eyes fixated on a sight he certainly didn’t expect to see in the cold fresh waters of Lake Michigan.

“I didn’t think it was real,” Castaneda said. “I thought it was fake–like maybe a toy.”

gator 1 Alligator In Lake Michigan Surprises Kayaker: I Didnt Think It Was Real

A kayaker discovered an alligator in Lake Michigan today.

As soon as Castaneda spotted the tail moving, he said he called 911, stunned.

“Cause I didn’t know who to call,” he said.

The gator’s mouth was taped shut, said Rob Carmichael, curator for the Wildlife Discovery Center in Lake Forest, where the alligator is being taken.

“I knew it wasn’t supposed to be here–that it couldn’t defend itself,” Castaneda said. “It had its mouth closed so it was gonna die if I just left it there.”

The animal was “hissing a little,” Carmichael said, adding that the sound was a good sign that it wasn’t on the brink of death.

“You’d probably be upset too if someone left you for dead,” he said.

The mystery surrounding how the alligator arrived in the lake and why it’s mouth was taped is still being mulled over by workers at the Wildlife Discovery Center.

Carmichael suspects the animal was dumped by its owner–thrown away with no chance of surviving.

“(Why) it was done like this is the big mystery,” Carmichael said. “I think sometimes people will get these animals without really doing their homework and have no idea what they’re in for.”

Alligators have been found several times in the area where the animal was spotted on Monday, he said.

Gator sightings in Lake Michigan have become a sort of “fisherman’s tale” over the years.

Keith Pomocmik was out fishing in the lake Monday and said he sometimes looks for gators when he’s on the lake.

“I was actually looking for them,” Pomocmik said. “Every now and then I take a little peek-a-boo–you know what I mean–see what I could find out there, but unfortunately I didn’t run across an alligator.”

Castaneda said he wasn’t scared when he first spotted the animal.

“I wasn’t really freaked out,” he said. “It was just weird–out of the ordinary.”

The scaly Great Lakes guest was doing fine health-wise Monday evening, aside from being slightly underweight.

If his blood work returns with normal results, he will have a new family at the Wildlife Discovery Center, where four other gators call home.

“I think he’s gonna be A-OK,” Carmichael said.

Charlie De Mar