Park rangers are offering a $10,000 reward to get their hands on whoever shot and killed three endangered southern sea otters in the Santa Cruz area. Two of the slain animals washed up on beaches in Santa Cruz and a third in nearby Aptos about two weeks ago, according to Max Schad, a wildlife officers with the state Department of Fish and Wildlife. A fourth dead otter washed up at Natural Bridges State Beach in Santa Cruz, but rangers were unable to determine, because of its deteriorated condition, whether it had been shot. Southern sea otters, also known as California sea otters, once were plentiful along the Pacific coast from Mexico to Washington.