Growth, Feed Utilization, Blood Biochemical Variables, Immunity, Histology of the Intestine, Gills and Liver Tissues, and Carcass Composition of the European Seabass (Dicentrarchus labrax) Raised Using Different Water Sources

Given the shortage of freshwater, mariculture is a promising method to maintain the development of aquaculture. This study compared the impact of two different groundwater sources of saline water on the productivity and overall health status of juvenile seabass. With the same stocking density, seabass fingerlings with an average body weight of 12.0±0.25 g fish-1 and an average length of 10.9±0.3 cm fish-1 were raised for a 210-day experimental period using the following three treatments: (T1) seawater source in concert tanks, (T2) underground saltwater in concert tanks, and (T3) underground saltwater in cages (Wadi Maruit Lake). The results showed that fish grown in T1 exhibited better growth performance, FCR, immunity, kidney and liver enzyme activity, while no major differences regarding the histomorphology of the liver, gills and intestine between tested groups. Even though T1-reared fish recorded a better performance in terms of fish growth performance and feed utilization (FCR) compared to T2-reared fish, underground saltwater was proven to be suitable for marine aquaculture. This will open up new opportunities for marine fish farming in desert lands, as the variations in fish performance, FCR and health status between T1 and T2 are relatively small. Further research is needed on both the proper places that include brackish and/or full-strength saltwater that might be exploited in creating marine aquaculture projects, as well as the water quality's suitability for the target marine organisms, especially the content of heavy metals.