The movie Star Trek 4 was a large contributing factor to public awareness of whaling and other threats to the humpback whale species.
The movie involved time travel, and taking a pair of whales from 1986 to a future where they were already extinct.
Have you not seen all of tos as the series or movies or both? The movies may be worth a detour in your watching, they don’t give much if anything away of the series and at least half are good, well 2 and 4 for me, I haven’t watched the rest in ages except 1, that one is hit or miss for people but good sci fi. 4 may be odd to get into if you didn’t see 3 is all, I don’t recall the rest as much, haven’t seen them since the 90s.
I have seen maybe 5 episodes of tos and I don’t care for Shatner’s acting at all and I just can’t get into it. I’ve seen one of the movies but I can’t remember what one. I know it was a newer one cuz it had data in it.
If you’re up for watching the movies, I’d recommend 2, 3, 4, and 6. You can skip 1 and 5. 3 is ok, but needed to understand the timeline.
Oh 5 is definitely worth a watch I’d say! You have David Warner, you get to see Kirk, Spock, and McCoy singing around the campfire, some great Scotty scenes and lines (“What’re ye standin’ around fer? D’ye not know a jailbreak when ye see one?!”) and Spock’s half-brother Sybok, the Laughing Vulcan.
Just don’t take the main story too seriously and you’ll have a good time!