Comparing clear-water RAS and biofloc systems: Shrimp (Litopenaeus vannamei) production, water quality, and biofloc nutritional contributions estimated using stable isotopes

Abstract

Indoor shrimp aquaculture systems can be used to produce fresh, never-frozen, quality shrimp near metropolitan seafood markets regardless of season and climate. However, questions still remain regarding what type of production system is best suited to maximize indoor production. In this project, two types of systems were compared: clearwater (CW) RAS and biofloc (BF) systems. Three, 1.36 m 3 tanks were assigned to each of the two treatments; CW tanks had external settling chambers, two foam fractionators, and external biofilters, all operated continuously. BF tanks had settling chambers and one foam fractionator which were operated as needed to control solids accumulation. Shrimp weighing 0.42 g were stocked in all tanks at 250 m-3 and grown for 55 days. Ammonia and pH levels were significantly (P < 0.05) higher in the CW treatment, while nitrite, nitrate, and turbidity were all significantly higher in the BF treatment, although all parameters remained within acceptable ranges for shrimp growth. Shrimp mean harvest weight was significantly higher, biomass (kg m-3) was significantly greater, and FCR was significantly lower in the CW treatment; there were no significant differences in survival between treatments. Isotope levels indicated that shrimp in the BF treatment obtained a portion of the C (18-60%) and N (1-18%) in their tissues from biofloc material; however, this effect did not positively influence production in that treatment. By nearly eliminating solids from the water and using an external biofilter, substantially better water quality was maintained in the CW systems, which may have been a major contributor to the improved shrimp production in that treatment.

Effect of biofloc technology on water quality and feed utilization in the cultivation of gibel carp (Carassius auratus gibeliovar. CAS III)

“…First, biofloc contained high-protein levels, and it could be harvested by some omnivorous fish or shrimp as a feed source (Avnimelech, & Kochba, 2009;Ray et al, 2017). First, biofloc contained high-protein levels, and it could be harvested by some omnivorous fish or shrimp as a feed source (Avnimelech, & Kochba, 2009;Ray et al, 2017).…”

“…In conclusion, BFT was successfully applied in aquaculture due to the following features. (Avnimelech, 2007;Ray, Drury, & Cecil, 2017). Second, BFT could make full use of water and land resources (Avnimelech, Verdegem, Kurup, & Keshavanath, 2008;Verdegem et al, 2006); Third, the biofloc produced enough protein and other various nutrients to serve as feed for aquatic organisms in the aquaculture system.…”

Effects of a partitioned aquaculture system on water quality and growth of Penaeus vannamei

“…Recirculating systems (Menasveta et al, ; Mires, Amit, Avnimelech, Diab, & Cochaba, ; Ray, Drury, & Cecil, ), biofloc monoculture (Ray et al, ; Wasielesky, Atwood, Stokes, & Browdy, ) and polyculture (Li et al, ; Sánchez‐Romero, Miranda, & Elisa, ; Tian et al, ) are used in intensive aquaculture ponds to alleviate the accumulation of organic compounds. The concept of integrated aquaculture is based on the idea of culturing compatible species that occupy different ecological niches and feed on the different food resources in the farm for maximum fish production (Dong, ; Jana, Banerjee, & Jana, ).…”

Pegada hí­­drica cinza de sistema de cultivo intensivo de camarão-branco em água salobra

“…Essas características pressupõem o melhor gerenciamento da água e do solo dos cultivos intensivos, por meio de manejo adequado dos animais e, consequentemente, uso mais eficiente da água, possibilitando maior densidade de estocagem com menor promoção de impactos ambientais, devido à significativa redução de efluentes gerados. (SAMOCHA et al, 2012;PIERRI et al, 2015;RAY et al, 2017). Embora a geração de efluentes seja menor no sistema de cultivo sem renovação de água, o impacto sobre o meio ambiente dependerá diretamente da concentração de nutrientes que será liberada por meio do efluente, somada à capacidade do corpo receptor de assimilar os mesmos compostos, conforme alertado por PIEDRAHITA (2003), já que muitos sistemas ainda não utilizam o reuso da água de cultivo.…”