Pacific white shrimp (Litopenaeus vannamei) cultured in recirculating aquaculture systems (RAS). Effects of density on growth, mortality, and welfare

Abstract

Aquaculture is a rapidly growing industry and one of the most vital pillars in addressing the increasing global demand for food. Different farming systems and strategies have been developed to achieve more modern and innovative ways of farming, involving automated and more accurate technologies, such as recirculating aquaculture systems (RAS). The Pacific white shrimp, Litopenaeus vannamei, is one of the most common species in shrimp farming. L. vannamei are usually cultured in industrial monoculture systems, hence, few studies have investigated the effect of using RAS technology to cultivate L. vannamei. This study aimed to investigate the impact of two stocking densities (Low Stocking Density, LSD, initial density 180 individuals/m2 and High Stocking Density, HSD, initial density 283 individuals/m2) on the growth, mortality, and welfare of L. vannamei cultured in a clear-water RAS.

The treatment with the LSD had overall better welfare and lower mortality. The treatment with the HSD displayed the lowest welfare score, which may have been caused by unforeseen events, such as a detached water outlet and white muscle necrosis (WTD). The survival was poor for both treatments in this experiment, but significantly lower in the HSD group.

The overall growth of L. vannamei was similar between treatments throughout the experiment, whereas the mean final weight was higher in LSD group. Accordingly, the results in this trial indicate that the growth of L. vannamei cultivated in RAS is only moderately affected by density. However, it has been well documented for biofloc systems and ponds that density does affect the growth of L. vannamei. It is therefore suggested that more research on the cultivation of L. vannamei in RAS is needed.