Bacteriological water quality of recirculating aquatic systems for maintenance of yellowtail amberjack Seriola lalandi

Abstract

The bacteriological water quality associated with marine fish farming systems can be a determining factor in the development of disease, and understanding this quality is fundamental for the prevention and control of possible disease outbreaks. In the present study, the bacteriological water quality of a yellowtail amberjack Seriola lalandi broodstock maintenance system, composed of two units of a recirculation aquaculture system (RAS 1 and RAS 2), was determined. From February 2016 to January 2017, monthly samples of surface water were taken at six points in the two RAS systems: (a) from the water reception tank and (b) from filter 1 and (c) tank 1 (in RAS 1) and (d) filter 2 and (e) tank 2 (in RAS 2) and from a joint (f) discharge point. The bacteriological quality was determined by counting total heterotrophic bacteria (THB) and by molecular identification (16S rRNA gene). The number of THB showed a tendency to decrease in filters 1 and 2, to increase in tanks 1 and 2, and again increase in the discharge. The fluctuation of THB, in general, was from 1.0 × 103 to 2.9 × 105 CFU/mL. In total, 102 colonies were isolated, corresponding to nine orders and 52 species, and Vibrionales and Alteromonadales were the most abundant orders. The bacterium Vibrio harveyi, a pathogen of S. lalandi, was identified, as were other bacterial species that are known pathogens; however, no signs of disease or mortality events were recorded during the study. These results suggest that the bacterial community contributed to the maintenance of a balance in the RAS, which prevented the development of infectious diseases. Furthermore, the physicochemical parameters (temperature, oxygen, nitrogen compounds, and alkalinity) were maintained within the optimum range required by S. lalandi. Some zoonotic bacteria were found, as well as bacteria with probiotic and industrial uses. These results represent the first report on bacteriological quality in RAS for S. lalandi.

Temporal dynamics of bacterial populations in recirculating aquaculture systems for sea urchin production

“…Additionally, the opposite result was observed when feeding was done four days prior to the count, which was reduced in comparison to the preceding counts. This is in accordance with preview works showing that the number of bacteria can be affected by a number of factors, such as the organic matter load of food (Alfiansah et al, 2018;García-Mendoza et al, 2019;Heenatigala & Fernando, 2016;Leonard et al, 2002;Qin et al, 2016;Vasile et al, 2017) Sea urchins are known to be susceptible to poor water quality, especially when ammonia levels are high (Basuyaux & Mathieu, 1999;Lawrence et al, 2003;Rubilar & Crespi-Abril, 2017;Siikavuopio et al, 2004). Although some of the physicochemical parameters in this investigation were higher, it did not affect the welfare of the animals.…”

Water microbiota is not affected by stocking density of the yellowtail kingfish ( Seriola lalandi ) in a recirculating aquaculture system

“…The research performed by Garcia‐Mendoza et al. (2019) revealed that the phylum Proteobacteria was predominant in the culturing water of the yellowtail kingfish, including the orders Vibrionales and Alteromonadales (≈60%), whereas Bacteroidetes was the most dominant phylum detected in our study. This is because the approach used contemplated the metagenomics DNA present in water, whereas the former approach considered cultivated bacteria only.…”

“…(2017) argued that the microbiota in commercial‐scale recirculating and semi‐closed aquaculture systems rearing Atlantic salmon ‘can potentially have a great impact on the robustness and health of the fish’. Garcia‐Mendoza, Cáceres‐Martínez, Vásquez‐Yeomans, and Cruz‐Flores (2019) argued that the bacterial community contributed to the maintenance of a balance of the recirculation system of the yellowtail kingfish, preventing the development of infectious diseases; however, this approach contemplated targeted 16S rRNA gene amplification of bacteria cultured in trypticase soy agar supplemented with 2% NaCl. Detailed reports derived from DNA shotgun sequencing of bacterial communities thriving in the culturing systems of the yellowtail kingfish are still absent.…”

Microbiological and Physicochemical Quality Measurements of Some Fish Ponds in Nigeria

“…They become pathogenic when conditions such as temperature changes, dietary, hormonal stresses and other physiochemical parameters are favourable for the development of pathogenesis 13 , the condition that fishes are cultured may be potentially stressful.…”