Speaking about the need for species diversification in the Mediterranean aquaculture sector, during his presentation at Aquaculture Europe 2014 in San Sebastian, Spain, Jorge Dias said that the target is to achieve the mass scale production of meagre.
To make a transition to meagre production as smooth as possible, it is important that meagre share the same grow-out technology as that currently used for sea bream and bass aquaculture, said Mr Dias. This will save time and experimentation which would be required if new technology was needed.
So far, the nutritional needs of meagre have not been well studied and the question has been raised of whether they can cope with vegetarian diets, as this would reduce the costs associated with fish meal based diets and also improve the sustainability of its production.
So far, studies of juvenile meagre have generated positive and exciting results.
When looking at their protein requirements, juveniles showed a 7-fold increase of initial body weight in just 42 days – showing that meagre grows very fast.
An increase in crude protein levels also positively correlated with feed efficiency.
In order to maintain this good growth, the optimal crude protein requirement for juvenile meagre is therefore fairly high at 53-55 per cent. Meagre is not a good species for protein sparing.
Looking at the dietary fat requirements, Mr Dias explained that optimal fat levels should be at 17-18 per cent, as this level gave the best body weight performance.
Meagre has also shown to be a more sustainable species to farm as it copes well on a vegetable diet. When all 60 per cent of fish oil in the diet was replaced with vegetable oil, growth was not affected at all said Mr Dias.
Although meagre has shown some impressive results, it was however discovered that if temperature levels fall to 14-19oC, meagre growth is severely reduced.
Mr Dias identified that 17-18oC seems to be the threshold for reduced growth and that going forward, this is an important criterion for the economic profitability of farming meagre.