While Europe’s trout farming is only bettered in the scale of its harvest by its Atlantic salmon production, it is an industry that historically makes few waves. On closer examination, though, the trout sector is polarizing: The traditional market, comprising whole fish sold in sizes of 400-500g, is in slow decline; while at the same time, there is growing market demand for fillets produced from larger fish as many European consumers seek simpler, more convenient cooking formats.

In terms of …