Pretty sure that's gonna affect more than the planet's ecosystem. Something more catastrophic, say like how the other moon revolves around the planet causing a possible collision and an impending doom to all life as they know it.
@JennyTals lol, it will for sure affect the tides a bit, but we don't actually know how big or how far the moons are from the planet. The attractive gravitational force is affected by 1/r^2 and the equation is something like GMm/r^2 = F. I'm not sure which scenario leads to the least amount of problems that fit the image so long as these moons are somehow much denser as well as the planet they are on and if the size was lots different.
The rotation would stabalize eventually as he destroyed the moon as if it were just teleported away.