Thanks for the comments everyone.
GoM & Anty, the locations were
1) just west of the Leuty Lifeguard station (inside the designated off leash dog run)
2) standing on the Unwin street bridge which is under construction, so the channel has been drained.
3) the docks/parking lot at the foot of Poulson Street (just off of Cherry)
4) looking east across the Unwin Street bridge
Neea, I have no idea as to how the sculptures occured. There may well be some small shrubs under them, but I can't be certain.