Line of action:

Status:

Execution date:

General objective:

Development and optimization of new functional feeds based on the partial substitution of fishmeal by meals from micro and macroalgae biomasses for use in the growth of turbot fingerlings (Scophthalmus maximus), based on the principles of sustainability and environmental protection in aquaculture.

Specific objectives:

1. In vitro evaluation of the nutritional composition of macro and microalgae biomasses to be used to replace fishmeal and fish oils.
2. In vitro evaluation of the nutritional characteristics of formulated functional feeds.
3. In vivo evaluation of the effect of formulated functional feeds on the growth and health of turbot fry.

The IEO conducted experiments where turbot was fed for 60 days with the following feeds: CTC and CT: commercial and experimental control; U5 and U10: Ulva compressa 5% and 10%; M5 and M10: 5% and 10% microalgae consortium.

The results obtained in the growth study, in height and weight, did not present significant differences between the diets and it was possible to observe that:

• The hepatosomatic index (IHS), calculated after 30 days of diet supply, showed that there is no difference between controls (CTC and CT), nor between TC and diets with the different algae. Differences were only found between the CTC and M5 with respect to M10, since it presented a lower IHS index. In relation to IHS at 60 days, the controls remained unchanged between them and between the algae diets. It should be noted that the U5 diet presented an IHS similar to the experimental one, but with differences with respect to the commercial one.
• Studies of intermediate metabolites indicated that serum lactate is inferior in animals fed the U10 diet, which could suggest that anaerobic metabolism, used under unfavorable conditions, is not being necessary.
• The fatty acids in the experimental feeds seem to be better balanced than those in the CTC feed, since there is no excessive accumulation of triacylglycerides in the liver.

Among the dissemination activities of the project, we highlight:

• The dissemination day of the project, whose prior dissemination was carried out through press releases on the website of the IEO and the University of Cantabria, among others. The event was attended by researchers from the IEO, AZTI and INCAR-CSIC, U. Cantabria, Cantabrian Maritime Museum, TACSA, Rodecan S.L. and interested public.
• Participation in the II Congress of Young Marine Researchers, in the XXII Forum of Marine Resources and Aquaculture of Galician Estuaries and in the EAS Berlin, through the presentation of posters about the project and its results.
• News of the project has been published on the profiles created by Algadiet on the social networks of Twitter, Facebook and Youtube, as well as on the accounts of the IEO of Gijón.