RESEARCH ON NUTRITION TOWARDS THE SUSTAINABILITY OF MEAGRE AQUACULTURE

IPMA - Portuguese Institute of the Ocean and Atmosphere EPPO - Aquaculture Research Station, Avenida do Parque Natural da Ria Formosa, 8700-194 Olhão, Portugal (*pedro.pousao@ipma.pt)

Europe needs to highly increase their aquaculture production for different marine species in order to supply consumer's needs and diversify products. T his activity must increase facing challenging European regulations on animal welfare, respect environment and obtain high quality products.  To attain this ambitious objective is important to implement research strategies integrated with the industry. Aquaculture research station (EPPO), in the South of Portugal, is a marine core facility with conditions to perform research at different scales.

Meagre (Argyrosomus regius )  is a fast-growing fish species with a high potential for production, processing (e.g. fillet, freeze, sushi, canning, etc.)  and to diversify cultured species in Southern Europe. Additionally, this species can be reared in recirculation (RAS) systems that can be integrated with clean and competitive source of energy (e.g. photovoltaic), promoting an ideal growth with a controlled and optimal temperatures during the entire production cycle and/or pre-fattening for offshore cages.

The aim of this  communication is to discuss some of the main advances on the research developed during the last 12 years at EPPO . Several experiments were carried out to achieve important basic information on meagre nutritional requirement, namely level of dietary protein, the adequate ratio of protein:lipid , growth performance with alternative ingredients to fish meal, growth enhancement with different levels of phospholipids and different ratios of DHA and EPA.

Fish growth is directly related with temperature and protein levels, however trials performed at EPPO have shown that the temperature has a crucial effect on meagre growth and efficiency on protein utilization (Figure 1 and 2) .

Sustainability of aquaculture feeds is a very hot topic and progressively fish meals tend to be replaced by vegetable, sub products of the animal industry (non-ruminant sources), and more recently by insect meals. However, this substitution can lead to unbalanced levels of amino acids and fatty acids. Results on trials with feeds supplemented with histidine, methionine and taurine show the importance of this supplements on growth performance and welfare.

This study had the support of the project DIVERSIAQUA (Mar2020 16-02-01-FMP-0066) and DIVERSIAQUA II (Mar2020-P02M01-0656P)