Never allow the sophonts at the Galactic Uplift Bureau’s Surreptitious Assistance Department too much free time. Or access to trashy Old Earth vidshows, apparently. GUB-SAD operatives can get themselves into all sorts of trouble that way.
The basic problem is this: most oxygen-nitrogen water worlds in the Milky Way galaxy have roughly similar biospheres, and that’s not even remotely accidental. A standard biological package of photosynthetic bacteria was apparently introduced to every planet that looked like it could support it (don’t ask anybody in the various Galactic governments who, or Who, did that). So, you can introduce new species into a particular planetary mix. If you have that sort of mind.