An initial round of data removed from the devices last week is being analyzed to see if things like construction work on a nearby bridge might be disturbing them.
Scientists are monitoring the group of about 12 dolphins they've allowed to remain in the Shrewsbury and Navesink rivers.
The decision to rescue the dolphins only if they seem to be in imminent danger has angered animal advocates. They say the dolphins may die this winter if they aren't helped back to sea.
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