That's not really how ethical problems work. They are supposed to define why we should or shouldn't do something. Even saying "nah dawg, fish tasty" would be more reasoning than you've provided.
You've not provided any reasons sufficient for me to consider eating fish or meat unethical. The issues you mentioned are ones I consider morally irrelevant to the ethical nature of eating these animals, and so I reject the claim that it is unethical.
So, you consider it ethical to bycatch, fish species to extinction, destroy marine environments and pollute the ocean freely despite there being ample alternatives to receive the nutrients you can get from fish? Please explain how these are irrelevant. Unless you personally catch each of your fish?
You're the one claiming they are, and you've failed to provide any support. The burden of proof is on you to show that it is unethical. A claim which is asserted without support can be dismissed just as easily.
Sure, yeah, claim like "yeah it's ethical to eat fish" with no reasoning behind it despite much prompting. You're basically claiming the that either the points I've mentioned are not things that happen, or that they are totally ethical to do. So I'm not going to waste my time.
I am merely rejecting your claims that it is unethical, as you haven't provided any grounds to support it.
I never claimed either that the points you mentioned do not happen or that they are ethical to do. I said they are irrelevant to the question of whether it is ethical to eat fish and meat.