New Jersey environmental officials are offering the state's assistance in determining what's behind an apparent high number of dolphin deaths over the past several weeks.

The state Division of Fish and Wildlife is working with the nonprofit Marine Mammal Stranding Center in Brigantine.

It has offered the use of conservation officers and state boats to recover dead or dying dolphins.

State officials say it appears the deaths are part of a natural disease cycle and not related to water quality, which they say has been high this summer.

The state says the Marine Mammal Stranding Center has responded to 21 dolphin deaths along the New Jersey coast since July 9. Necropsies have so far confirmed four died of pneumonia.

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