NewsCopter 7 captured images of the dolphin in the South River in Old Bridge near the Old Matewan Road overpass.
The mammal has been making a scene in the area for more than an hour, and many people have gathered on the bridge and in the area to take photos.
An Eyewitness News viewer captured up-close video of the dolphin:
The South River runs off the Raritan Raritan River, which connects to Raritan Bay -- but this dolphin is no where close to the bay. It does not appear to be in distress, though.
The dolphin has been making an appearance above water every 1 1/2 to 2 minutes.
Eyewitness News reached out to the Marine Mammal Stranding Center, and they said the dolphin is not considered stranded at this time -- it's free swimming. They do have people at the scene and are waiting for word from the National Marine Fishery Service on the next step. As long as the dolphin is in the water, responding units cannot go in.