A pilot study on culture of Asian seabass Lates calcarifer in coastal cage at Cox´s Bazar coast, Bangladesh

Bangladesh ranked fifth in global aquaculture but mariculture is not popularized yet. The limited availability of protected sites and the probable conflicts with other activities such as fishing, tourism and navigation are key factors likely to influence mariculture development in Bangladesh, besides finance, expertise and government policy. As a leading fish in the coastal environment, seabass (Lates calcarifer) is one of the promising species for the development of culture technique in the coastal region of Bangladesh. The present study aims to find out the suitability of seabass culture using floating net cages (locally available materials) taking special care to suitable stocking density and low-cost feed ingredients in the coastal region of Bangladesh. Considering all these criteria, the Bankkhali River Estuary, Cox´s Bazar has been selected. The fingerlings were collected from the local fry collectors of the coastal areas around one month after the breeding season of June-July and sorted out the fingerlings of uniform size due to cannibalistic habit and the sorted fish (19.5 ± 1.03 g) were acclimatized before stocking to the cages. The initial stocking rate was 50 indivs/m² and 45 days later it was reduced to 30 indivs/m² till harvest. Three supplementary feeds; flesh of pangush fish (Pangasius sutchi), mussel meat (Perna viridis) and flesh of chewa fish (Trypauchen vagina) were used with three replicates. Feeds were applied trice daily in first two months at the rate of 8% of their total biomass and then twice daily at the rate of 5% till harvest. After 120 days of culture fishes were harvested (Table 1). SPSS-Post Hoc comparison indicates that pangush fish as feed gives the best result followed by mussel meat and chewa fish. The hydrological parameters viz., temperature, pH, salinity, dissolved oxygen, ammonia, alkalinity, hardness, nitrate, phosphate, TDS, TSS and secchi depth were measured two times per month and were found at optimal levels for the normal growth of seabass. The results obtained indicated that cage culture of seabass in the coastal areas of Cox's Bazar region, Bangladesh can provide significant advantages in terms of fast growth using low cost trash fish with the effective utilization of unused and derelict lotic water bodies.