What? you say. Actually, this is huge. The dirty secret of farmed fish is that they are fed the ground-up smaller fish that are still available in the wild. Since we’ve driven most of the larger fish into near-extinction except in the few areas where sane fisheries management is practiced, this is the only way to have adequate supplies of the best-loved food fish. The problem is that most fish (except tilapia and a few others) just won’t eat their vegetables. In most of the developed world, this doesn’t matter all that much because fish are a luxury food. However, in many countries, fish are an essential source of calories with no option for replacement and even the populations of junk fish that are used to feed the farmed fish are rapidly being depleted.
Australia’s CSIRO has developed a food for prawn farms, based on cultured microbiota, which requires no fish and is not only appealing to prawns (apparently) but enhances their growth. This is a breakthrough technology which allows us to plan for truly sustainable fish farming. It is hard to overstate the importance of this, especially if it can be extended, as hoped, to other species.