I'm a little lost here. Andy, Have you gotten more information than what is going on here? and BTW, most new pennies don't have enough copper to really do much good and using pennies is not really a good idea if your keeping fish as you really can't contol the ppm to a safe level by simple breaking dwn of the coins, more acidic the water the faster the copper breaks down. Sam, are you wanting fish and wildlife or just water? There's several options to this pond, yes copper will keep algae or at least most algaes completely out of the system, 2ppm of copper and no invertabrates will survive, such as snails. I'm not sure about the mosquito fish, IMO, if they were there, good they were removed, if considering, I wouldn't, far better choices to choose from. If just water and no life, a simple swimming pool 3" tablet of chlorine and the water will stay clear but no life will survive at all, Or there is the blue addative that countrols algae and makes the water real blue and fish safe. I forgot who used it on there pond for a start up but in this case, it would be so shallow that the blue water could actually add to the effect.
Sam what are you wanting the area to do? a pond with or without life?