Synergistic interactions of zeolite, stocking density, and water exchange: A holistic approach to optimizing aquaculture performance of juvenile European seabass (Dicentrarchus labrax)

Abstract

Effective water management is an essential component of sustainable fish farming practices, particularly in the context of global water scarcity. The accumulation of ammonium ions (NH4+) from fish metabolism necessitates frequent water changes, posing a challenge to the sustainability of fish farming operations. Zeolite materials have emerged as a promising solution, offering enhanced ammonium cation removal compared to conventional nitrifying bacteria. This innovative approach alleviates the pressure on water resources and promotes environmental sustainability in fish farming. Over 75 days, this study examined how zeolite, stocking density, and water exchange affected European seabass water quality and growth. 250 kg of seabass, 25.61 ± 2.39 g/fish. Three factors: zeolite levels (Z: 0, 10, and 15 ppt), density (D: 1, 2.5, and 5 kg/m3), and water exchange (W: 10, 25, and 50 %), using 81 hapas with 0.5 m3 vol each (triplicates for each treatment) fixed in concrete ponds, fish were randomly distributed among 81 experimental hapas in 27 ponds. This research illuminates the potential benefits of various therapies. Zeolite in seabass culture improved water quality. It reduced ammonia derivatives, improving water quality. Adjusting seabass stocking density to low or high improved water quality measures. This change kept dissolved oxygen levels within the target range, providing a good home for farmed fish. Zeolite supplements, reduced stocking density, and optimum water exchange improved European seabass growth, along with water quality improvements. These interventions improved feed consumption and growth rates. These approaches promoted fish growth and reduced stress by limiting the negative effects of high stocking density. The study also examined immune-related, hematobiochemical, and plasma biochemical characteristics after the interventions. Zeolite supplementation, to low stocking density, and water exchange improved these characteristics. They strengthened the European seabass' immune system and preserved healthy plasma and hematobiochemical parameters. In conclusion, optimizing European seabass culture with zeolite (15 ppt), stocking density (1 kg/m3), and water exchange (50 %) enhances water quality, growth performance, and physiological parameters. This contributes to improved aquaculture sustainability and efficiency. Further research is required to fully elucidate the molecular mechanisms of those factors that affect fish health and aquaculture practices.