Welp, I moved them.....
They were attached only to the abeloney shells. I moved the larger of the two, ~4", in a perfect spot that fitted both the abeloney shell as well as the clam...perfect. The smaller, ~3.5", I had to cut from the other abeloney shell that the larger was conected to as well. It was not as dificult as I had expected. The smaller clam was a little more difficult to place. Having had been partially cut, it was not attached to the abeloney shell as well as the larger, and it kept moving in the current. After alot of adjusting, I think I found a good place for it.
They are huffing a bit, trying to test thier footing, I suspect. Its lights out for now, we'll see how they are in the morning.....