They are believed to be common dolphins, which were spotted just after noon off Bridge Street. They could be seen surfacing for air. Experts say it is likely the pod made its way up from Newark Bay, clustering in this portion of the Hackensack River.
"Common dolphins, this far away from the ocean is a worrisome thing," said Hugh Carola, program director for the Hackensack Riverkeeper. "The worry is they will strand."
Carola was also watching several of the dolphins and says this is a concern.
"Animals that are normally found in regular, deep-sea oceans get up into rivers where it's much less salty, organs have troubles," he said. "And they get stressed and they don't feed and they get confused."
It was about a year ago that a pod of 16 bottlenose dolphins were stranded in the Shrewsbury River, raising a debate over whether they should be rescued or allowed to find their own way back to the ocean.
The Marine Mammal Stranding Center is aware of this new pod and does not believe it is in immediate danger. But officials are discussing a possible plan of action.