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The goal of this study was to characterize the main operational processes adopted by a shrimp aquaculture pond system in Brazil and to account the flows of energy use. The characterization was carried out via application of the Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRIMA) methodology. The accounting of the energy flows was made through the quantification of the energy coming from economically required resources. Based on the data and characteristics identified in Brazilian shrimp farms, a hypothetical farm consisting of four nursery tanks, nine ponds, feed, fertilizer and general deposits, a refectory, restrooms and dressing rooms, garage, and main and secondary access roads. In this hypothetical shrimp farm, the water pumping was performed by a 20 hp pump, and aeration was performed via 4 hp paddle‐type aerators. A biphasic operating system and a semi‐intensive production regime were adopted, with a initial stocking density of 43 shrimp m−2 and harvest occurring when the shrimp reached an average weight of 12 g. The cultivation cycle lasted 90 days and include the pond preparation and curing period. The final yield was estimated to be 3500 kg ha−1. The total energy cost was calculated as 835.597 MJ. The most energy inputs were feed, fuels and lubricants and electricity. Shrimp production in ponds is a very intensive activity relative to the energy demand and that increasing energy efficiency is one of the essential conditions for the truly sustainable production of long‐term Brazilian shrimp farming not only for environmental but also mainly for economic reasons.

Water salinity is among the most important factors influencing the distribution, abundance, growth, and survival of Crassostrea gasar, an important aquaculture resource grown in estuarine environments in diverse regions of the world. The goal of the present work was to evaluate the effects of different salinities on survival and the tissues of C. gasar under laboratory conditions. Two experiments were performed using adult oysters from five marine farms located in the bay of Guaratuba, Brazil. In Experiment 1, the daily survival rates were evaluated after the oysters were submitted to gradual acclimatization at salinities ranging from 0 to 65 gL -1 and maintained in the laboratory without feeding for up to 365 days. In Experiment 2, the oysters were exposed to salinity from 0 to 50 gL -1 for up to 30 days without feeding and possible histological alterations caused by salinity were assessed. Three tolerance ranges of C. gasar to salinity were identified: "Optimal" (between 4 and 40 gL -1 ), "Tolerable" (between 2.1 and 3.9 and between 41 and 50 gL -1 ) and "Intolerable" (less than 2 and greater than 50 gL -1 ). No evidence of histological alterations was observed in oysters exposed to the different salinities.

In this work, we identifi ed the bacterial microbiota associated with farmed oystersin estuarine regions of four states in the north eastern region of Brazil. During the drought and rainy seasons, for eight months, twenty oysters were sampled seasonally from seven different marine farms. In the laboratory, DNA extraction, amplifi cation, and sequencing of the 16S rRNA gene were performed to establish the taxonomic units. We identifi ed 106 genera of bacteria belonging to 103 families, 70 orders, 39 classes, and 21 phyla. Out of the total, 40 of the genera represented bacteria potentially pathogenic to humans; of these, nine are known to cause foodborne diseases and six are potentially pathogenic to oysters. The most prevalent genera were Mycoplasma, Propionigenium, Psychrilyobacter, and Arcobacter. The results indicate the need for more systematic monitoring of bacteria of the genus Mycoplasma in oyster farming operations in the Brazilian north eastern region. Currently, Mycoplasma is not one of the microorganisms analysed and monitored by order of Brazilian legislation during the oyster production and/or commercialization process, even though this genus was the most prevalent at all sampling points and presents pathogenic potential both for oysters and for consumers.

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