Here is the full list of all 10 Song of the Deep (EU) trophies - there are 5 bronze, 4 silver and 1 gold.
Feed the Queen Leviathan.
Pay your respects to the Watcher and drop a flower on her final resting place.
Purchase all upgrades
Kill a Tremorclaw Crab as Merryn
Destroy the Forbidden City forever
Commune with the giant seahorse
Defeat the Fomori Boss
Activate the Deeplight
Defeat the Watcher
Meet the Merrow