Introduction
European pikeperch (Sander lucioperca) is highly sensitive to environmental and handling stressors in aquaculture (Dalsgaard et al. 2013, Baekelandt et al. 2018), limiting the intensification of its farming in recirculating aquaculture. To increase the production of this species sustainably these cultivation modes are of interest (Steinberg et al. 2018) especially to the growing number of small-scale (10 – 20 tons) operations. Plant bioactive compounds can be effective feed ingredients that reduce stress and improve fish growth and immunity. Furthermore, plants also release exudates into the medium surrounding their roots. The influence of such plant metabolites on pikeperch or the performance of an aquaponic system has not been studied to date but could provide an option to improve its cultivation.
The European INTERREG Research project PERCIPONIE aims to develop perciculture in aquaponic systems through improvements on efficiency and fish welfare. One avenue of research is the identification of bioactive compounds emitted by plants cultivated in aquaponics and to test their effects on the growth and immunity of pikeperch. Based on an international consortium of partners, the project brings together stakeholders from research and industry to ensure scientific excellence and applicability of results.
Materials and Methods
The results of the final project stage will be presented. In a hydroponic cultivation experiment, metabolites of plant origin released into the system by different species of vegetables and aromatic plants were identified through untargeted metabolomics analysis. Supported by literature on their chemical properties (size, biological reactivity, solubility etc.) a number of polyphenols were identified. Ongoing experiments test the effect of these molecules on juvenile pikeperch i) in aquaponics systems comparing plant mono-cropping to plant diversity and unplanted control systems and ii) through direct addition of biomolecules to the cultivation water in recirculation systems. Their impact on zootechnical parameters such as growth, stress response and immunity will be evaluated. The results will provide insights into how agro-ecological approaches can be applied to further pikeperch aquaculture.
References
Baekelandt S, Redivo B, Mandiki SNM, Bournonville T, Houndji A, Bernard B, El Kertaoui N, Schmitz M, Fontaine P, Gardeur JN, Ledoré Y, Kestemont P (2018) Multifactorial analyses revealed optimal aquaculture modalities improving husbandry fitness without clear effect on stress and immune status of pikeperch Sander lucioperca. Gen Comp Endocrinol 258:194–204.
Dalsgaard J, Lund I, Thorarinsdottir R, Drengstig A, Arvonen K, Pedersen PB (2013) Farming different species in RAS in Nordic countries: Current status and future perspectives. Aquac Eng 53:2–13.
Steinberg K, Zimmermann J, Meyer S, Schulz C (2018) Start-up of recirculating aquaculture systems: How do water exchange rates influence pikeperch (Sander lucioperca) and water composition? Aquac Eng 83:151–159.