I skimmed this paper, but it's interesting.

One thing to note, is that their salinity (ECs) are good, but not great. Generally, you want them under 2 dS/m in growth media. 3-4 is considered fair, but with some limitations, so they might have to refine their desalinization process a bit more, or you know, use freshwater fish.

The N input from the fish manure (I feel weird just typing that) is actually pretty good. About 100 lb/ac, which is the upper limit requirement for most crops. They would most certainly need P amendment, though, and that could cause a lot of issue with their aquaculture if it makes its way into the system.