Those stones under the log... you should remove them. And also add moss on it so it looks more realistic, after all it's located in wet area. And that "vortex" next to the shark... just remove it. When you sum it up, it's pretty good
Nice. But in my opinion you should remove the stones under the log and fix up the waterfall. Also remove that yellow tree to the bottom right and the vortex, also the wall lamp and cobweb. Still nice though