Green Leafs/Algae?

Robust Ghostpipefish - Solenostomus cyanopterus, can reach a length of 17 cm (6.7 in) and it is the largest of the ghost pipefishes. The body may be grey, brown, pink, yellow, or bright green, with small black and white dots. This cryptic species looks very similar to a drifting piece of seagrass. The caudal fin may be truncated, rounded, or lanceolated; the caudal peduncle is quite short or absent. The pelvic fin is sexually dimorphic. It is an uncommon species related to pipefishes and seahorses. It can be distinguished by the presence of the pelvic fins, the prominent spiny dorsal fin, and 27-35 star-shaped plates on the skin.

This particular spotting is of a pair in green variation, looking more like floating seagrasses.