People are raising concerns about a pod of dolphins that are swimming in a northern New Jersey river.
Bill Sheehan of the Hackensack Riverkeeper group fears there's not enough food in the river in the winter to sustain the dolphins.
The Marine Mammal Stranding Center in Brigantine has been contacted. The center says it can't act until the dolphins are in distress.
In 2009, a pod of dolphins that got stuck in the Shrewsbury and Navesink rivers spurred a tug-of-war between animal rescuers and federal wildlife officials over whether the dolphins should be removed. Three of those dolphins did not survive.