[pvaldes]

> The impact to open-water fisheries can be undone if the markets appreciate farm-raised fish for their quality.

Is not so simple. Marine Aquaculture needs huge amounts of wild fishes to feed the farm fishes. The more aquaculture you have, more pressure on some fisheries. Also less pressure on other, that in fact adds an extra of pressure to the first fisheries. China has increased its fleet in the last decades for that.

All this "fishes are sentient" stuff is toxic for your job. My advice is to avoid it like a plague. This people would be typically unable to keep a carnivore fish alive.

[rohxnsxngh]

You raise a valid point about feed. It is true that carnivorous species like salmon still have FIFO ratios above 1.0, meaning they consume more wild fish than they produce. That is a real concern for those species.

That said, the feed picture has changed a lot over the past two decades. The overall FIFO ratio for aquaculture dropped from 0.63 in 2000 to around 0.22 to 0.28 by 2017 depending on how you calculate it. Modern feeds are increasingly plant based with soy, barley, and other terrestrial proteins making up the bulk of formulations. Up to 30% of fishmeal now comes from processing byproducts rather than whole wild fish. There is also a lot of work happening on alternative proteins like insect meal, algae, and single cell proteins.

The species matters a lot here. Tilapia, catfish, and carps use very little wild fish in their feed. Salmon and shrimp are the outliers that drive most of the wild fish dependency. We are currently working with trout which sits somewhere in the middle.

On the sentience discussion, I am not going to dismiss people who care about fish welfare. It is a legitimate concern and the science on fish cognition is evolving. Our technology actually reduces stress on fish compared to manual handling which involves netting, anesthesia, and physical manipulation. If people care about welfare then better measurement tools that minimize handling should be part of the solution.

[pvaldes]

> The species matters a lot. Tilapia, catfish, and carps use very little wild fish in their feed

The big problem with herbivores is that nobody really likes their muddy taste. This market only works if you can raise this fishes for free with organic discards. Sea Aquaculture is a totally different planet.

I'm aware of the inclusion of vegetable proteins on the diet since decades, but is a tricky issue. Too much of them and the fishes don't grow well, and too low and the costs of feeding your fishes raise over the value of your fishes in the market. And you still need to import your food. This is a big point. Unexpected 10% more of tariffs just because the president farted that night, means the death of your company.

[Pgrech]

A lot of research and development has been conducted in diet plans to have an optimal balance for growth while incorporating alternative protein sources, reducing reliance on wild caught fish for feed.