The production of Turbot, Scophthalmus maximus, in RAS is fully commercial, with a growing EU industry and demand for this highly prised fish.

At the Llyn Aqua pilot plant in N Wales we have held a breeding stock of selected fish since 2002 and rear about 5 tonnes per annum as a test species to further develop our closed systems. 
Fish of up to 100g are kept in stacked shallow raceway nursery systems (< 10 cm depth) and thrive at up to 25 Kg / m2 and larger fish show optimum growth in shallow (0.3 - 0.7m) round or raceway tanks at densities up to 40 Kg / m2.  Although the fish will tolerate densities of even 60 Kg/m2 we prefer to maintain optimum growth at a lower stocking density.  Shelves within deeper tanks as a means of increasing production have proved NOT to be successful.
In smaller fish FCRs of 0.7 are common, while overall FCR to market size of 1 - 1.5 Kg is around 1.00.  Unstressed, larger fish will remain motionless for 23 hrs and 55 mins per day, only moving once per day to feed!