Reviews in Aquaculture, 1–24 doi: 10.1111/raq.12408 Biofloc technology: principles focused on potential species and the case study of Chilean river shrimp Cryphiops caementarius David Antonio Ulloa Walker1,Marıa Cristina Morales Suazo2 and Maurıcio Gustavo Coelho Emerenciano3 1 Programa Cooperativo Doctorado en Acuicultura, Universidad de Chile, Universidad Catolica del Norte, Pontificia Universidad Catolica de Valparaıso, Chile, Grupo de Marcadores Inmunologicos. Laboratorio de Genetica e Inmunologıa Molecular. Instituto de Biologıa, Pontificia Universidad Catolica de Valparaıso, Valparaiso, Chile 2 Universidad Catolica del Norte, Facultad de Ciencias del Mar, Departamento de Acuicultura- Larrondo 1281, Coquimbo, Chile 3 Santa Catarina State University (UDESC), Aquaculture Laboratory (LAQ), Laguna, SC, Brazil. Present address: CSIRO Agriculture and Food, Aquaculture Program, Bribie Island Research Centre, Bribie Island, Qld, Australia Correspondence Abstract Marıa Cristina Morales Suazo, Universidad Catolica del Norte, Facultad de Ciencias del The accelerated growth of aquaculture has caused environmental impacts in many Mar, Departamento de Acuicultura-Larrondo countries. Examples include the use of large volumes of water, discharge of efflu- 1281, 1781421 Coquimbo, Chile. Email: ents with high nutrient content, the occupation of large areas, natural habitat [email protected] alternation and the escape of exotic species. Biofloc technology (BFT) is an aqua- culture tool that requires minimal water exchange, promotes the nutrient recy- Received 11 September 2019; accepted 9 cling optimizing resources and produces natural food in situ by forming December 2019. suspended microbial aggregates in the water (bioflocs). These microorganisms provide multiple benefits such as water quality control, pathogen resistance and nutritional supplementation. Species such as Litopenaeus vannamei and tilapia have been successfully applied in BFT. In addition, there are also an increasing number of studies focused on alternative species with promising results. This paper describes essential aspects of biofloc technology, its application in aquacul- ture and the potential to extend its benefits to new aquaculture species such as Chilean river shrimp Cryphiops caementarius. This paper describes the future challenges of this technology as well as opportunities for its application. Key words: Aquaculture, biofloc, candidate species, carbon source, Chile, microbial aggregates. 2008; Crab et al. 2010a). This technology has been devel- Introduction oped mainly in tropical and subtropical geographical areas Biofloc technology (BFT) is a production tool for aquacul- that have abundant natural light for omnivorous organisms ture based on zero or minimal water exchange that can that encompass certain stages of production or the entire reduce discharges of nutrient-rich effluents into the envi- life cycle (Neal et al. 2010). ronment as well as the negative impacts associated with the In recent years, research and scientific publications on escape of cultivated species and the spread of disease BFT have intensified, both in species with commercial value (Wasielesky et al. 2006; Avnimelech, 2007; Samocha et al. and other candidate species that could benefit from the 2007). This technology has been successfully applied in application of this technology. These include freshwater freshwater fish such as tilapias (Oreochromis aureus, fish such as Clarias gariepinus (Putra et al. 2017), Labeo O. niloticus, O. mossambicus) (Avnimelech et al. 1989; rohita (Mahanand et al. 2013) and Rhamdia quelen (Poli Avnimelech, 1999; Brol et al. 2017; Verster, 2017), marine et al. 2015). Other species of commercial interest such as crustaceans such as Litopenaeus vannamei (Burford et al. the ornamental fish Carassius auratus (Faizullah et al. 2015) 2004; Wasielesky et al. 2006; Samocha et al. 2007), Penaeus and Pseudotropheus saulosi (Harini et al. 2016), as well as monodon (Anand et al. 2013, 2014, 2017) and freshwater the sea cucumber Apostichopus japonicus (Chen et al. prawn like Macrobrachium rosenbergii (Asaduzzaman et al. 2018b), belonging to the Phylum Echinodermata, account © 2020 Wiley Publishing Asia Pty Ltd 1 D. A. Ulloa Walker et al. for a wide range of potential species that can be cultivated or as a tool during early cultivation during nursery phases. with BFT. The BFT was originated in the 1970s at the French Research Among the future challenges of this technology are the Institute for Exploitation of the Sea (IFREMER), located in exploration and validation of its potential to cultivate new Tahiti, French Polynesia, where Gerard Cuzon was one of species that require alternative models of commercial or the pioneers and in partnership with private companies small-scale aquaculture production. Such approach can from the United States of America (Emerenciano et al. also be applied to vulnerable species as a tool for both stock 2012b; Anjalee-Devi & Madhusoodana-Kurup, 2015). It recovery and repopulation in wild. Based on data previ- was later expanded to commercial shrimp farms (e.g. in ously collected, the river shrimp Cryphiops caementarius is Tahiti, Sopomer farm). In the 1990s, scientific studies and an endemic species in Northern Chile and Southern Peru commercial pilot-scale trials began at the Waddell Maricul- that has great commercial potential (Meruane et al. 2006a, ture Center in the United States of America with penaeid b) and social impact (Acuna~ et al. 2003). In Chile, this spe- shrimp led by J. Stephen Hopkins and with finfish at the cies is classified as vulnerable in the wild species classifica- Technion-Israel Institute of Technology led by Yoram Avn- tion register (RCE, Ministerio de Medio Ambiente, 2011) imelech (Emerenciano et al. 2013d). In the mid-2000s, two and is also listed in the International Union for the Conser- major research centres began several studies that were fun- vation of Nature (De Grave et al. 2013) as a species of con- damental to the development of BFT technology in South cern. C. caementarius belong to the Family Palaemonidae, America at Federal University of Rio Grande-FURG (Bra- as same as those of the genus Macrobrachium, such as zil) research centre led by Wilson Wasielesky and North M. rosenbergii, M. carcinus and M. americanum. Omnivo- America in the Texas A&M University (Corpus Christi rous species with marked territorial behaviour are relevant Campus, USA) led by Tzachi Samocha both focused on for the implementation and validation of BFT. penaeid shrimp. Thanks to the training of human resources A fundamental aspect of aquaculture is the acquisition of in these institutions, various professionals spread BFT juvenile individuals. The process for obtaining juveniles is knowledge and implemented commercial farms worldwide. attainable in Chile since reproduction control exists to There was a significant increase in number of scientific maintain broodstock. This premise ties into the themes of publications on the subject of biofloc technology worldwide. aquaculture diversification and small-scale systems, which The number has increased from less than 10 in 2009 to more projects the development of the aquaculture industry in the than 100 publications in 2018, with studies conducted Northern part of the country while considering new pro- mainly in Brazil, China, the United States of America, Mex- ductive models for technologies and species of interest for ico and India (Scopus, 2019), helping to strengthen the tech- research and commercialization. As such, C. caementarius nology and boost the industry. Another important factor for is considered as a candidate species for diversification and such progress was the wide range of courses and lectures small-scale aquaculture in continental waters since repro- offered in both scientific and commercial events for the sci- duction control is now feasible (Morales & Meruane, 2012; entific community, academia and aquaculturists. However, Moreno et al. 2012; Rojas et al. 2012) along with juvenile despite the progress and benefits of BFT as reported by the production (Morales, 1997; Morales et al. 2006; Meruane scientific community and academia, there is still room for its et al. 2006a,b). It is therefore possible to bring this aquacul- commercial expansion. For example, in Indonesia, it is esti- ture proposal using BFT as an alternative model for mated that only 20–25% of shrimp production has occurred sustainable and environmentally friendly aquaculture using biofloc technology (Thong, 2014). Among the reasons development, with a high potential to expand into arid behind such scenario are the higher implementation and areas of Northern Chile. production costs (e.g. electricity) compared to traditional The objectives of this paper are to describe (i) the princi- land-based systems, and the complexities in management ples, essential aspects and applications of biofloc technology and implementation of the technology, which requires in aquaculture; (ii) the potential to extend BFT benefits to greater technical knowledge and permanent monitoring of new candidate species such as the Northern freshwater water quality (Avnimelech, 2015). shrimp C. Caementarius; and (iii) describe the opportunities It is important to note that the application of biofloc and future challenges that such technology currently faces. technology has focused on primarily omnivorous aquatic organisms. Assessments of candidate species for BFT should include their adaptability to intensive farming con- History of biofloc technology ditions, the phase