Fish farms are not the environmental win they claim themselves to be. They can sometimes actually make things worse because they’ll often take wild caught fish as feed too!

The sheer quantity of wild fish used in salmon farms is also a growing concern. About a fifth of the world’s annual wild fish catch, amounting to about 18m tonnes of wild fish a year, is used to make fishmeal and fish oil, of which about 70% goes to fish farms

https://www.theguardian.com/environment/2021/feb/11/global-salmon-farming-harming-marine-life-and-costing-billions-in-damage

Environmental impact is not limited to salmon farming either. All kinds of fish farms dumps large amounts of waste into the environment

For a world annual shrimp production [in fish farms] of around 5 million tons, 5.5 million tons of organic matter, 360,000 tons of nitrogen, and 125,000 tons of phosphorous are annually discharged to the environment https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353277/

They can also drive deforestation in some parts of the world too

Conversion to aquaculture is the most prevalent driver of mangrove deforestation across the tropics over the last 50 years generating substantial carbon emissions. Preventing further aquaculture expansion within mangrove forest areas will be essential to achieve national emission reduction targets in mangrove-holding countries.

https://onlinelibrary.wiley.com/doi/10.1111/gcb.14774

To get anything close to what that used to look like would take massive reductions in consumption and production across the board. Not just shifting what type of fish people eat. Having a lot, lot less of it overall

It’s not just a higher population. Per capita consumption of fish has gone up quite a bit in the past decades, though has leveled off

Which is a global pollutant as opposed to more local ones

That’s why I noted Local Pollutants as opposed to global ones

The article also site other studies too. (It calls the N=40 preliminary early research)

Tends to doesn’t means always will ¯\_(ツ)_/¯

There’s slowly starting to be more and more awareness. I’ve started to see larger outlets start to call things like that out more often (though very much still not all there yet). For instance, the New York Times just recently ran a piece about how animal feed is the largest user of the colorado river and how we need to think about changes in what we eat: The Colorado River Is Shrinking. See What’s Using All the Water