SERIOLA project advances details on its pilot trials of juvenile fattening

The team of the project "Diversification of the Spanish aquaculture through the optimization of the cultivation of seriola (Seriola dumerili) - SERIOLA" advances satisfactorily in the realization of the scientific-technical activities of this initiative, that looks for the development of a new commercial species in Spain by improving its larval process and the optimization of the fattening.

SERIOLA is a project framed within the National Aquaculture Plans and co-financed by the Ministry of Agriculture, Fisheries and Food (MAPA) and the European Maritime and Fisheries Fund 2014-2020. In this project led by the University of Las Palmas de Gran Canaria (ULPGC), also participate the Institute of Aquaculture of the University of Santiago de Compostela and the Institute of Agricultural Research and Training and Fisheries of Andalusia (Centro El Toruño).

Currently, in addition to the experimental trials, is already underway a series of validation tests to fatten juvenile seriola. "After the good results in obtaining natural spawning of seriola in the Institute of Aquaculture and Sustainable Ecosystems (IU-ECOAQUA) of the University of Las Palmas de Gran Canaria, the resulting juveniles have been sent to the facilities of the participating entities and collaborating partners to carry out various tests on a pilot scale. Thus, for example, the Galician Aquaculture Cluster and the Aquaculture Institute of the University of Santiago de Compostela have been sent juveniles to perform pathological tests and validation tests in Recirculation Systems in Aquaculture (RAS)," says Javier Roo, national coordinator of the project and researcher responsible for the program within IU-ECOAQUA.

In addition, another batch of juveniles has been sent to the Technological Centre CTAQUA, as responsible for the validation of fattening in the Mediterranean. CTAQUA has made in its facilities the stabling of the specimens and later shipment to the Murcian company Piscifactoría de Albadalejo SL, in San Pedro del Pinatar, for fattening in open sea conditions (off-shore) in the Mediterranean. "A part of the individuals of the lot remains in our facilities in El Puerto de Santa Maria, with the aim of performing also a validation of growth," says Maria del Mar Agraso, technical director of CTAQUA.  The Technology Centre plans to carry out tests in the coming months to validate a diet, developed by the IU-ECOAQUA team, which includes functional ingredients specific to seriola.

On the other hand, it is foreseen in the framework of this project, that a new batch of seriolas - which are still in production in the facilities of IU-ECOAQUA - will be sent to the company Acuipalma SL, in Tazacorte, on the island of La Palma, for the validation of the fattening phase in off-shore facilities in the Atlantic, being directly the Aquaculture Business Association of Spain (APROMAR) responsible for monitoring this activity.

The actions of this project also include tasks related to carry out of tests of nutritional profiles and diets performance. To this date, the ULPGC has established the optimum levels of inclusion of Omega-3 polyunsaturated fatty acids (n-3 PUFA) in fattening diets; and a new test has been launched in which the incorporation of different functional ingredients in food is being evaluated. "With these trials, the aim is to improve some of the challenges that are appearing both in the fattening of seriola in SAR systems and in cages, such as bacterial and parasitic infections or the effect of the drop in winter temperatures in the Mediterranean", explains Javier Roo.

Within the framework of this project, an exhaustive list of risk agents affecting the species has also been drawn up, which shows that parasites are the most frequent agents with the highest incidence. This work is being developed by the Institute of Aquaculture of the University of Santiago de Compostela (IA-USC).

In this second phase of the project, an evaluation of the antimicrobial and antiviral capacity of a series of currently available disinfectant agents has been carried out. "These laboratory studies have provided significant results for the sector, as they will provide a greater variety of disinfectants, as well as efficacy data against bacteria and viruses at risk in the cultivation of this species. However, the evaluation has yet to be transferred to culture situations, to confirm that they maintain the same level of efficacy as in laboratory tests", says Carlos Pereira Dopazo, director of the Aquaculture Institute and researcher in charge of the programme within the European Union.

In addition, the IA-USC has carried out an in vivo study on seriola fry to determine their response to infection with the nerve necrosis virus (NNVV), proving that, at certain sizes, the species can become resistant to the virus.

Currently, IFAPA Centro El Toruño is carrying out biochemical analyses of the different organs of fish to determine the influence of low salinity on stress and animal welfare. Researchers from the Centre have carried out a series of recirculation tests (RAS) to different salinities, to check both growth and resistance to parasitosis with Neobenedenia sp. These tests have allowed establishing the best salinity conditions in a range close to 22 ppm.

Regarding the pH tests, although they have not yet concluded, they point to a better performance when approaching 7.8, a value close to that of seawater. "Once the different organs are analysed with biochemical techniques, differences can be established at a molecular level between the different treatments", says Jose Luis Muñoz, researcher in charge of the project at IFAPA El Toruño.  

The advances made within the PNA SERIOLA were recently presented at the world and European aquaculture conference "AQUA 2018", which took place in Montpellier (France) from 25 to 29 August. Likewise, it is expected that the final results will be presented during the next National Aquaculture Congress, as well as through a workshop aimed at companies and entities interested in the cultivation of this species during 2019.

The SERIOLA project has been co-financed through the Research Grants of the National Aquaculture Plans 2016, granted by the Ministry of Agriculture, Fisheries and Food (MAPA) and the European Maritime and Fisheries Fund 2014-2020, with an approved budget of 796,669.43 euros.