A video of a recognizable fin gliding through the waters in a popular Nova Scotia park has generated thousands of shares in less than 24 hours. 

“We were just watching people fish, and all of a sudden we see this fin popping through,” said Alex Fraser, who took the video.

That fin drew the attention of dozens of people on the Dewolf Park Boardwalk on Friday, shocking many when they got a closer look.

“At first we all thought it was a shark,” said Fraser. “And then it came right up close to us. Pretty scary.”

Less than a day later, her video record of the sighting was shared by nearly 8,000 Facebook users.

But after some consideration, even Fraser is questioning whether it was actually a shark.

And she’s not alone.

“It is definitely, I can say 100 per cent, an ocean sunfish,” said shark expert Warren Joyce of the Bedford Institute of Oceanography.

Joyce says he isn't surprised by the mix-up.

“Their dorsal fins do look fairly similar when they're in the water, but from the video, you can see the animal below the water has an elliptical shape,” said Joyce. “You can see a large dorsal fin that flops over occasionally, as opposed to cruising through the water.”

While it was a viral case of mistaken identity in this instance, it doesn't mean sharks aren't out there.

“It certainly is possible,” said Joyce. “I have had a couple of records of sharks in the Bedford Basin before, but it is quite rare. Ocean sunfish often get mistakenly identified as being sharks.”

With files from CTV Atlantic’s Cami Kepke.