Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters

O objetivo deste trabalho foi avaliar o crescimento da ostra-do-mangue Crassostrea gasar cultivada em ambiente marinho e estuarino. As ostras foram cultivadas por 11 meses em sistema de espinhel, em dois locais de estudo – São Francisco do Sul e Florianópolis –, em Santa Catarina. A concentração de clorofila‑α, a temperatura e a salinidade da água foram registradas semanalmente. As ostras foram medidas mensalmente (tamanho da concha e ganho de peso) para avaliar o crescimento. No final do período de cultivo, os pesos médios de carne úmida, carne seca e concha foram determinados, bem como a distribuição das ostras por classes de tamanho. Seis modelos não lineares (logístico, exponencial, Gompertz, Brody, Richards e Von Bertalanffy) foram ajustados aos dados de crescimento das ostras. As médias finais de tamanho da concha foram maiores em São Francisco do Sul do que em Florianópolis. Além disso, as ostras cultivadas em São Francisco do Sul apresentaram distribuição mais uniforme nas classes de tamanho do que aquelas cultivadas em Florianópolis. Os maiores valores médios de peso de carne úmida e peso de concha foram observados em São Francisco do Sul, enquanto o peso da carne seca não diferiu entre os locais. O ambiente estuarino é mais promissor para o cultivo de ostras.The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites – São Francisco do Sul and Florianópolis –, in the state of Santa Catarina, Southern Brazil. Water chlorophyll‑α concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy) were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Crescimento da ostra-do-mangue Crassostrea brasiliana (Lamarck, 1819) cultivada em dois ambientes no estado de Santa Catarina

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-graduação em Aquicultur

Estratégias de biorremediação de sedimentos em viveiros de piscicultura com bactérias do gênero Bacillus: estudo em escala laboratorial

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2021.A intensificação da piscicultura traz consigo a produção de um grande volume de resíduos orgânicos com potencial de gerar prejuízos à produção aquícola. Frente a este problema, o objetivo deste estudo foi avaliar a capacidade de bactérias do gênero Bacillus e de enzimas extracelulares no incremento da decomposição da matéria orgânica presente no sedimento de viveiros de piscicultura. No primeiro experimento, com duração de nove dias, amostras de sedimentos foram colocadas em caixas plásticas de 18L, juntamente com a aplicação de dose única de inóculos bacterianos contendo Bacillus subtilis e B. licheniformis, com as seguintes concentrações: 1,21 x 106 UFC g-1 (equivalente a 75 g ha-1), 2,41x 106 UFC g-1 (equivalente a 150 g ha-1), 4,82 x 106 UFC g-1 (equivalente a 300 g ha-1) e 1,61x 107 UFC g-1 (equivalente a 1000 g ha-1), além de um tratamento controle, com adição apenas de solução salina. Após secagem, as amostras foram analisadas e os tratamentos 75, 150 e 300 g ha-1 apresentaram reduções de 18 a 22% nos teores de matéria orgânica. No segundo experimento, também com duração de nove dias, amostras de sedimentos foram colocadas em embalagens plásticas de 1L, compondo um experimento inteiramente casualizado, com seis tratamentos e dois controles, com cinco repetições cada. Nos tratamentos controles (Controle e Controle - 3) foi aplicada apenas solução salina (0,65% NaCl) em uma dose única e em três doses com intervalos de três dias, respectivamente. Nos demais tratamentos foi efetuada aplicação de solução salina (0,65% NaCl) em uma dose única e em três doses com intervalos de três dias contendo o seguinte: consórcio bacteriano de B. subtilis + B. licheniformis em concentração aproximada de 2,41 106 UFC g-1 (tratamentos B150 e B150 ? 3); consórcio de enzimas contendo xilanase, amilase, fitase, protease, hemicelulase e pectinase (tratamentos E150 e E150 ? 3); ou a mistura de ambos (tratamentos B+E150 e B+E150 ? 3). Foram analisados os teores de carbono (orgânico total, orgânico particulado e orgânico associado aos minerais), de nitrogênio (total, orgânico particulado e associado aos minerais) e suas respectivas relações C/N. Nenhum tratamento incrementou a redução dos teores de carbono. O tratamento B150 foi capaz de reduzir os teores de nitrogênio. Este estudo indica que a aplicação das bactérias Bacillus subtilis e B. licheniformis é capaz de incrementar a decomposição da matéria orgânica presente no sedimento de viveiros de piscicultura, diferentemente do consórcio de enzimas, que não demonstrou tal capacidade.Abstract: The intensification of fish farming brings with it the production of a large volume of organic waste with the potential to generate losses to aquaculture production. Faced with this problem, the objective of this study was to evaluate the capacity of bacteria of the genus Bacillus and extracellular enzymes in increasing the decomposition of organic matter present in the sediment of fish farming ponds. In the first experiment, lasting nine days, sediment samples were placed in 18L plastic boxes, together with the application of a single dose of bacterial inoculum containing Bacillus subtilis and B. licheniformis, with the following concentrations: 1.21 x 106 UFC g-1 (equivalent to 75 g ha-1), 2.41 x 106 UFC g-1 (equivalent to 150 g ha-1), 4.82 x 106 UFC g-1 (equivalent to 300 g ha-1) and 1.61x 107 UFC g-1 (equivalent to 1000 g ha-1), in addition to a control treatment, with the addition of saline only. After drying, the samples were analyzed and the treatments 75, 150 and 300 g ha-1 showed reductions of 18 to 22% in the contents of organic matter. In the second experiment, also lasting nine days, sediment samples were placed in 1L plastic packages, composing a completely randomized experiment, with six treatments and two controls, with five repetitions each. In the control treatments (Control and Control - 3) only saline solution (0.65% NaCl) was applied in a single dose and in three doses with intervals of three days, respectively. In the other treatments, saline solution (0.65% NaCl) was applied in a single dose and in three doses with intervals of three days containing the following: bacterial consortium of B. subtilis + B. licheniformis in an approximate concentration of 2.41 106 UFC g-1 (treatments B150 and B150 - 3); consortium of enzymes containing xylanase, amylase, phytase, protease, hemicellulase and pectinase (treatments E150 and E150 - 3); or the mixture of both (treatments B + E150 and B + E150 - 3). The levels of carbon (total organic, organic particulate and organic associated with minerals), nitrogen (total, organic particulate and associated with minerals) and their respective C / N ratios were analyzed. No treatment increased the reduction of carbon levels. The B150 treatment was able to reduce nitrogen levels. This study indicates that the application of the bacteria B. subtilis and B. licheniformis is able to increase the decomposition of organic matter present in the sediment of fish farms, unlike the consortium of enzymes, which has not demonstrated such capacity