A dolphin was found dead Wednesday afternoon in the Navesink River, the second to die there in the last two weeks.

Teri Frady, a spokeswoman for the National Oceanic and Atmospheric Administration, said the dolphin appeared to be somewhat decomposed, indicating it had been dead for some time.

Although details remained sketchy, it appears the animal was part of a pod of dolphins that has been living in the Navesink and Shrewsbury rivers since June.

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Animal rescue experts and the federal agency have clashed in recent months over whether the dolphins should be removed from the river and brought back out to sea.

"We need to agree on a plan to get these dolphins out of there," said Bob Schoelkopf, co-director of the Marine Mammal Stranding Center in Brigantine, who has been pushing federal officials to intervene for several months. "It's a shame two animals had to die to get us to this point."

The latest dead dolphin was found across the river from where the first one was found, at a marina in Fair Haven.

Schoelkopf said he has no doubt the dead dolphin was part of a group of 15 that has been plying the two rivers since early June.

There were no obvious signs of trauma to the dolphin, but it was somewhat decomposed, making it hard to initially tell what killed it.

The dolphin was taken to a veterinary center in Pennsylvania on Thursday morning, where a necropsy will be performed.

The wildlife agency has said it would not act to move the dolphins unless it appeared they were in danger or becoming ill.

However, volunteer rescuers are worried that waiting too long could invite an even worse replay of a disastrous scenario that resulted in the deaths of four dolphins who lingered too long in the Shrewsbury River in 1993.

Ice eventually closed in on them and they drowned.