A lot of fish you would buy at the supermarket is farm-raised. Especially catfish, salmon, and tilapia.

Unfortunately, a lot of farm-raised fish are fed smaller fish from natural ecosystems, effectively shifting but maintaining the overfishing problem.

If you care about omega-3 (you probably should) without contributing to overfishing (again, imho you probably should), get an algal-oil based supplement. Prices are pretty competitive nowadays.

Good thing about farm-raised fish is that it is less contaminated, because it is usually mostly plant-fed. But it also makes it less nutritious.

Depends on what materials one classifies as a “contaminant”.

Also, they might be "mostly" plant fed but a big part of their diet is made up of wild fish!

Not sure why you are being downvoted. Salmon (mentioned in other siblings) is a perfect example of over fishing, and the farmed stuff tends to be of terrible quality and fed absolute garbage/treated terribly.

Salmon is found in high-latitude systems around the globe in both hemispheres. Overfishing is something that occurs to populations, not species. Most of the salmon populations that I am familiar with are not over-fished, but have suffered from spawning habitat loss due to dams and logging. Those are major issues and they continue to negatively affect those populations; you are doing the loggers and dam builders a favor by blaming fishing, which is far easier (and more politically palatable) to regulate.

I hope I've not misunderstood but if you are saying vitamin D deficiency is a 'small health risk' then that needs correction. Never mind the validity or not of the paper in question. Anyone reviewing the peer-reviewed literature on vitamin D for the last decade or so would conclude it's a very bad idea indeed to be deficient. For those who don't get much sun exposure, a blood test is recommended and will put people on the right track.

Does aquaponic tilapia not have D3?