As a resident of a first world country I stopped eating all seafood about 15 years ago. It seems unethical to support over-fishing if I have plenty of other good food to eat.
E.g. I would expect shrimp, mussels, clams to not be fed processed wild catch, unlike salmon.
https://phys.org/news/2012-02-tiny-shrimp-giant-carbon-footp...
The farms are inefficient, producing just one kilogram (2.2 pounds) of shrimp for 13.4 square kilometers (five square miles) of mangrove
But Asian shrimp farms produce over a million tons of shrimp per year:
http://www.shrimpnews.com/FreeReportsFolder/NewsReportsFolde...
If it takes 13.4 square kilometers of mangrove per kilogram of shrimp, Asian shrimp farms would occupy more than
13.4 * 1000 * 1000000 = 13,400,000,000
(13.4 billion) square kilometers of mangrove. That's about 26 times the surface area of Earth.
I've always thought less-than-ethical food products should be taxed more heavily, and the money should be used to subsidize the more ethical, healthier alternatives. Outright bans on certain product classes can be tremendously distortionary and have unintended side effects, but it's hard to imagine little pigouvian nudges being anything but beneficial to society.
Doesn't necessarily solve our problem here, but it might help the larger situation and with potentially bipartisan support (economic right positions rely on the consumer being able to make educated choices).
I absolutely agree with a carbon tax and a land tax to push the prices in the right direction. From what I recall, American meat is subsidized by the government, making it cheaper than anywhere else. I expect removing those subsidies would also have the support of anyone not bribed by the meat industry.
All too often, controversial opinions dominate the conversation because they get people talking. I think there's a lot we can do to improve things by working together across political lines.
This is a cherry picked argument, at least in the US, where "factory farms raise 99.9 percent of chickens for meat, 97 percent of laying hens, 99 percent of turkeys, 95 percent of pigs, and 78 percent of cattle" [1].
Besides, even in this ideal farm where the farmer treats the animals perfectly and lets them live long, fulfilling lives, they're still killing the animal at the end of the day. Hard to see how that is "treating [it] well".
[1] https://www.huffpost.com/entry/its-time-to-end-factory-f_b_1...
If you believe that it is unethical to raise livestock with fulfilling lives and then kill them for meat, by all means do not eat meat. I disagree, but I accept that as a valid, reasonable position to hold. I think most people are more concerned with animal cruelty specifically, and also have a lot of difficulty switching to vegetarianism.
In a happy coincidence, some of the healthiest fish are also some of the most sustainable fish.