Evaluation of Pacific Whiteleg Shrimp and Three Halophytic Plants in Marine Aquaponic Systems under Three Salinities

The effect of salinity on the growth performance of whiteleg shrimp (Litopenaeus vannamei) and three halophyte plants, red orache (Atriplex hortensis), okahijiki (Salsola komarovii), and minutina (Plantago coronopus), in a marine aquaponic system with biofloc was evaluated in this study. The experiment was conducted for 4 weeks, and the three treatments were 10, 15, or 20 ppt (parts per thousand). The growth performance of the shrimp and the three halophytes were affected by the salinity. Compared to the shrimp reared in 10 ppt, those reared in 15 and 20 ppt had higher final weight, weight gain rate (WGR), and specific growth rate (SGR), and lower feed conversion ratio (FCR). The results from shrimp raised in 15 ppt were 2.0 +/- 0.1 g, 89.9 +/- 2.2%, 2.3 +/- 0.0%, and 1.5 +/- 0.0, respectively, and those in 20 ppt were 2.0 +/- 0.1 g, 93.9 +/- 5.4%, 2.4 +/- 0.1%, and 1.4 +/- 0.1, respectively. On the other hand, the growth performance and nutrient content in halophyte plants decreased with the increasing salinity. In general, the three halophyte plants had better results in the 10 and 15 ppt treatments than those in 20 ppt. Therefore, the salinity of 15 ppt was suggested as the optimal condition for the integrated cultivation of whiteleg shrimp and the three halophytes in marine aquaponics. Additionally, they are compatible species for the development of marine aquaponics.