The bottlenose dolphin swimming around the South River in East Brunswick and Old Bridge has died.

Volunteers from NY/NJ Baykeeper with the dolphin in the South River (Marine Mammal Stranding Center)

The Marine Mammal Stranding Center, whose volunteers had been keeping an eye on the dolphin, reports on its Facebook page the mammal was found beached on a sandbar on Saturday morning as he was making his way up the river towards Raritan Bay.  Volunteers say the dolphin was having seizures and struggling to breathe in the shallows of the river where it beached itself.

The dolphin was 9-feet long, weighed 400 pounds but appeared emaciated. MMSC expects a state veterinary pathologist to examine the dolphin in order to determine a cause of death. The dolphin appeared to be older with teeth ground down to almost nothing.

Many had gathered on the Old Matawan Road bridge for the past week to watch the dolphin swim around the river.The MMSC believed the dolphin was chasing bait fish and wound up in the river.

Late in the week, concerned that dolphins are not fresh water animals, volunteers from the Raritan Riverkeeper were trying to nudge the dolphin towards Raritan Bay but were unsuccessful according to NBC 10.