Another view of attachment scars on the tsunami dock. Again, I'm not enough of a bio person to have any real idea what I'm looking at. The circular spots look as if they might be some kind of barnacle; I was thinking perhaps cnidarians, sort of like sea anemones, but I don't know if any of those precipitate a calcareous base. Just in a bit from the upper left corner, and not really visible at this scale (right-click the photo, open in new tab for full-size), it looks as if there are the remains of an encrusting bryzoan of some kind. Spots where tube worms were cemented on are visible in several places. Finally, in the bottom middle and lower right corner, it looks like the greenish splotches were a variety of calcareous algae.