Hello! I would strongly encourage you to give the students guidance around what makes good observations (good, close up, and clear photos of wild organisms), specifically telling them not to post photos of people, food (grocery store bananas, onions, etc), or man-made items, and actively monitor everything they post (and make sure they know you’ll be watching)!
I’ve seen it quite a few times now, students will be encouraged to use iNat and they’ll start posting photos of each other, random objects, joke observations (photo of a fruit loops box tagged as a toucan), tons of blurry houseplants, and just generally flood the site with poor quality observations the community has to wade through and correct.
If students are posting from their own accounts, using a project that will catch everything they post is key to keeping an eye on them, and please take on the responsibility of moderating their observations! There should be consequences for posting nonsense. Teenagers are going to be teenagers, so it’s super important to make sure you’re not just setting them loose on this platform! Their misconduct impacts the other users. I imagine part of the issue is the students feel like they’re on an anonymous online platform where they can post whatever they wanted without consequences, and I hope that communicating an expectation of good conduct and a promise of oversight will help. Good luck!
There’s a useful guide here if you haven’t already read it: https://inaturalist.freshdesk.com/en/support/solutions/articles/151000170805