I don&#x27;t understand some of your claims:<p>&gt; <i>They convert 1.1-1.3 lbs of feed to 1 lbs of protein in 9 months</i><p>They eat 1.1--1.3 lbs of food each month during 9 months, that is 9x1.1 -- 9x1.3 = 9.9 -- 11.7 lbs in total and produce 1 lbs of protein? Or the eat in total only 1.1--1.3 lb of food during the 9 months an produce 1 lbs of protein?<p>&gt; <i>But here&#x27;s the real kicker--by providing the nitrogen that crops need</i><p>The fishes don&#x27;t fixate nitrogen. They can &quot;free&quot; some nitrogen compounds in their food, but the nitrogen compounds have to come from somewhere. IIRC only some bacteria can fixate nitrogen naturally, (i.e. transform some unuseful nitrogen from the air into useful nitrogen compounds, that may be used to build proteins). Some plants, like soy, are good host for these bacteria, but I never heard that fishes have a similar symbiotic relation.