Humans will mine, dredge, fish and plunder the seas lifeless, polluting anything they–we–cannot monetize.
I have been a vegetarian since 1980. I withdrew my consent from fishing the seas empty many years ago. It is not enough, but it is what I still do–withdraw participation and consent wherever I can.
ETA:
I get it that climate change is borking snow crab populations.
What I foresee is that it is nearly impossible to fully protect ocean biota, and that globally people will always try to cheat the system, like government controls, and poach, as long as it is financially rewarding for them.