The research carried out by researcher Valery Ravelo reveals that the use of functional ingredients of plant origin and environmental enrichment with microbubbles significantly improves the weight gain and welfare of aquaculture fish, also increasing their survival and reducing their stress levels.
A study by the Institute for Research in Sustainable Aquaculture and Marine Ecosystems (ECOAQUA) of the University of Las Palmas de Gran Canaria (ULPGC), through the Aquaculture Research Group (GIA), has revealed how environmental enrichment with microbubbles and the use of a plant-based adaptogen such as cannabidiol, individually or in combination, can favourably influence the welfare of juvenile European sea bass cultured in aquaculture farms.
The research, the result of the Master's Thesis entitled ‘Improving the welfare of sea bass (Dicentrarchus labrax) using adaptogens and environmental enrichment’, was carried out by the researcher Valery Ravelo under the direction of Dr. Daniel Montero Vítores, PhD. Daniel Montero Vítores, professor at the ULPGC and member of the ECOAQUA GIA group, and Dr. Silvia Torrecillas Burriel, researcher in aquaculture nutrition and health at the Institute of Agri-Food Research and Technology (IRTA) of the Generalitat de Catalunya.
More weight, more survival and less stress
The results of this study, with which Ravelo obtained the official title of Master's Degree in Marine Cultures after the successful defence of his TFT, showed that environmental enrichment with microbubbles significantly improved different growth parameters such as weight gain, final weight, specific growth rate and feed conversion factor. In turn, the use of cannabidiol did not generate negative effects on fish growth, improving health indicators and generating an improvement in fish welfare, opening the door to future research on its possible application in sustainable aquaculture.
In addition, this work has revealed that the use of these innovative strategies led to an increase in various welfare parameters, as the sea bass studied increased their survival and reduced their cortisol levels after stress.
In this context, the research work carried out by Valery Ravelo has therefore made it possible to advance knowledge on innovative strategies to improve the welfare of European sea bass (Dicentrarchus labrax), a key aspect for the sustainability of the aquaculture sector.
Researcher Valery Ravelo at a moment during the research.
Ravelo's research analysed various growth parameters, such as weight gain, specific growth rate and feed conversion factor. In addition, survival and different blood indicators, such as cortisol, and genetic indicators, in different brain regions such as the telencephalon, hypothalamus or pituitary, related to the stress response, were evaluated.
Innovative strategies
Studies such as this one, which apply novel strategies to ensure the welfare of fish in aquaculture, contribute to boosting the economic profitability and environmental sustainability of aquaculture production, as these animals face a constantly changing environment, where diets vary based on socio-economic factors and availability of ingredients. In addition, these fish, as a consequence of climate change, are exposed to variations in environmental conditions as well as emerging pathogens and pollutants.
Valery Ravelo, who is currently continuing her training in the PhD programme in Sustainable Aquaculture and Marine Ecosystems at the ECOAQUA Institute of the ULPGC, where she continues to explore new strategies to improve the health and welfare of fish in aquaculture, says that this research has been a key opportunity to deepen her specialisation in animal welfare within the field of aquaculture.
‘During the second year of the MSc, my scientific development grew exponentially. I was able to specialise and deepen my knowledge in the field of animal welfare in aquaculture, as well as develop research skills that have allowed me to present my results at national and international conferences, which has been a truly enriching experience,’ said Ravelo.
One of the tests carried out during Valery Ravelo's study.
This researcher is a graduate in Biological Sciences from the Complutense University of Madrid, opting for the environmental mention, and specialised in sustainable aquaculture through the International Master's Degree in Marine Cultures jointly organised by CIHEAM Zaragoza, which has also echoed this research, and the ULPGC.
His main areas of interest lie in the use of functional additives, such as essential oils and natural extracts, which can contribute to improving the sustainability of the sector by improving the general health of fish, a line of research in which he continues to delve with the development of his doctoral thesis.
The results of this study were presented in academic forums of great relevance, such as the XIX National Aquaculture Congress 2024, organised by the Spanish Aquaculture Society (SEA), in collaboration with the ULPGC through the ECOAQUA GIA group, last June in the Alfredo Kraus Auditorium in Las Palmas de Gran Canaria, as well as at the international congress AQUA 2024, co-organised by the European Aquaculture Society and the World Aquaculture Society in Copenhagen.