Keep in mind, I’m an anti-hero, not a boy scout…
I’d go into the most polluted places in the world and use the Temporal Bender there. All of the trash would be obliterated, saving the animals. Also, Aquaman would never let sea life get hurt, so I’m hoping he shows up and gets the animals away safely, but that’s more of an assumption, as I have no idea if he’ll do it. There will be less water, but there will still be water for the animals to live in, and most of the oil will be removed as well because it was in the water. While I’m in the past, however, I’ll kill Baby Darkseid. Then, I’ll come back home.
Basically, trash is gone, oil spill is eradicated, animals hopefully safe, and Darkseid dead! It’s a good day to be alive!