Work

Integrating Gammarus insensibilis in biofloc systems: A sustainable approach to nutrient enrichment and waste valorisation in aquaculture

Year: 2024

Type: article

Abstract: This research addresses the cultivation of Gammarus insensibilis in biofloc systems. The aim of the work was to valorise and to bioremediate aquaculture effluents while enhancing the nutritional value of bioflocs through the introduction of amphipods, which can be grown in close aquaculture systems. Two experimental diets (aquaculture waste detritus and commercial fish feed) were tested for amphipods in triplicated biofloc systems, against three control tanks without biofloc. The experiment was conducted over a six-week period at a temperature of 20°C in the absence of light. The water quality, the survival, lipid profile and fatty acid composition of the amphipods and the bioflocs produced were studied. Significant differences were observed in the water quality between the treatment groups and the control, since nitrifying bacteria were present in the bioflocs formed in the treatment tanks. Indeed, 100% mortality was reached in the control tanks from the second week of the experiment. The fish pellets diet resulted in a significantly higher total lipid content in the biofloc and amphipods than the detritus diet. The pellets also exhibited a higher proportion of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), although these levels were lower in the resulting biofloc. The wild amphipods displayed higher levels of saturated fatty acids (SFAs) and omega-6 PUFAs compared to the experimental groups, which demonstrated higher omega-3 PUFA contents, particularly DHA. The study highlights the nutritional advantages of pellet-based diets for amphipods, including improved survival and lipid content, while also emphasising the enhanced nutritional profile of the enriched detritus-based biofloc. We suggest that the integration of aquaculture detritus with supplemental aquafeed in BFT systems will support both the bioflocculation process and the nutritional needs of the amphipods, thereby creating a sustainable and efficient cycle of waste valorisation and live food production. Further research is required in order to study the complete life cycle of amphipods and their reproductive capacity in these systems. A lower water temperature and the inoculation of microalgae should be considered in order to achieve higher survival rates and PUFAs content.

Source: Aquaculture

DOI: 10.1016/j.aquaculture.2024.741922

Authors: Marta Castilla-Gavilán, José Manuel Guerra-García, Ismael Hachero-Cruzado

Institutions: Andalusian Institute of Agricultural and Fisheries Research and Training, Institut Des Substances et Organismes de la Mer, Nantes Université, Universidad de Sevilla

Language: English

Topic: Aquaculture Nutrition and Growth

Subfield: Aquatic Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Life below water, Zero hunger, Responsible consumption and production, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $4,000