Estimation of Growth Performance of Crassostrea virginica in a Recirculating Aquaculture System (RAS) in Cox’s Bazar, Bangladesh: A Case Study

Abstract

The current study was conducted at the Bangladesh Fisheries Research Institute in Cox’s Bazar, from February 2023 to April 2024. Oyster (Crassostrea virginica) growth and survival rate were studied in a recirculating aquaculture system (RAS). The study also evaluated the impact of various water parameters (viz., temperature, pH, dissolved oxygen [DO], salinity, alkalinity, nitrite, nitrate, and ammonia) on oyster development. Oysters were cultivated in T1, T2, and T3 using two replications for each treatment. RAS was used with continuous aeration throughout the two treatments (T1 and T2), while non-RAS continuous aeration was given during the control treatment (T3). 50, 60, and 55 oysters were presented in three treatments. Three distinct marine microalgae (Nannochlorum spp., Tetraselmis spp., and Nannochloropsis spp.) were added to tanks for feeding oysters. Statistically significant differences (p < 0.05) were found in the T1 therapy group, which had the highest specific growth rate per day (0.119%) and survival rate (92.85%), followed by T2 (87.5%) and T3 (77.5%). In addition, first treatment (T1) continuously measured the largest weight (36.08 g), length (6.51 cm), and width (6.43 cm); however, T2 showed a significant depth rate (4.44 cm). Optimum oyster population, salinity (29.5 ppt), pH (7.25), DO (5.12), temperature (30.75°C), and other water quality indicator levels displayed a significant correlation with oyster growth performance for the T1 group rather than T2 and T3. However, the T2 group was also treated under RAS circumstances. The findings demonstrated that RAS can significantly enhance oyster growth and survival-controlling water indicators, which provide valuable insights for sustainable aquaculture practices in the coastal areas of Bangladesh.