We’re doing that regularly now.

There are always algues and fish unless we go out of our way and poison the ocean.

You mean like the Pacific garbage patch? Or the numerous “spills” and effluent pipes that feed directly into the ocean? Perhaps the excessive overfishing or whaling or shark finning? Ocean drilling? Deep water mining? I think we’ve already got that killing the oceans thing managed.

There is of course always a chance something will survive.

Edit: like this fucking horse tail I’m fighting in my garden that’s been around for millennia. Dinosaurs walked on that shit. Makes a great addition to fertilizer but God damn already…