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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Využitie odpadovej vody z RAS pre produkciu mikrobiálneho proteínu. / Usage of wastewater from RAS for microbial protein production.

SADLOŇ, Patrik January 2017 (has links)
The aim of this diploma thesis was to analyse waste water quality from RAS, verification of its possible cleaning in a model of wastewater treatment plant using heterotrophic bacteria, experimentally compare the influence of used carbon source in the initial phase of bacteria cultivation and evaluation of biofloc usage in fish feed. Analysed water was obtained from rearing tanks, sewage water from mechanical filtration and tap water for filling the system. Wastewater treatment plant (built according to AS VARIOcomp K model) was divided into 3 parts (primary settling, activated part, secondary settling) and then filled with water from running BFT system. For carbon source comparing experiment 4 groups were used: flour, glucose, acetate and glycerol, each in 3 replications. Cultivation took 28 days and at the end the nutritional composition of each BFT system was evaluated. Water analyses showed that sewage water from mechanical filtration is nutrient rich and contain big amount of undissolved solids. This water is not suitable for purification in conventional system without pre-treatment. The model of water treatment plant purified approximately 50 l of water from vortex per day which was pumped back into RAS. Probably it would be capable of purifying bigger volume. Bacteria cultivation using different carbon sources is very similar to start-up of nitrifying bacteria in biofilter at the beginning. It was proved that biofloc is also capable of removing nitrates from water. The biggest measured concentration among groups was 1695 +- 438 mg.l-1 NO3- and in 6 days it decreased to 493 +- 409 mg.l-1. The average FVI for flour, glucose, acetate and glycerol were 102 +- 57; 267 +- 59; 219 +- 26 and 293 +- 9 ml.l-1 at the end of cultivation. Experiment comparing carbon sources also proved that nutritional composition of biofloc is similar to composition of commercial feed. Heterotrophic bacteria are also capable to cumulate heavy metals and mineral matter over time. Experiment with added biofloc to feed in amount 0 %, 25 % and 50 % did not show any statistically significant differences (p < 0,05) on survival rate, FCR and SGR between the groups of juvenile grass carp (Ctenopharyngodon idella).
2

Influence de l'environnement trophique de l'élevage en biofloc sur les performances physiologiques de la crevette Litopenaeus stylirostris : Étude de paramètres de la nutrition, de l'immunité et de la reproduction / Influence of trophic environment on in biofloc rearing on the physiological performances of the shrimp Litopenaeus Stylirostris : Study of parameters of nutrition, immunity and reproduction

Cardona, Emilie 04 March 2015 (has links)
Le biofloc est un système d’élevage intensif avec un faible renouvellement d’eau ; ainsi se développe une population diversifiée de micro-organismes (micro-algues, zooplanctons et bactéries) associée à de la matière organique qui forme les floculats. Ces derniers jouent le double rôle de filtre biologique et de complément alimentaire. Cette thèse a pour objectif de mieux comprendre le fonctionnement de ce système d’élevage et ses interactions avec la crevette Litopenaeus stylirostris. Dans cet objectif général s’inscrit deux objectifs plus spécifiques : (i) mesurer les gains zootechniques apportés par l’élevage en biofloc (ii) étudier les interactions trophiques entre le milieu d’élevage et la crevette en lien avec les performances zootechniques. Nos résultats montrent des gains relatifs de l’élevage en biofloc aux niveaux de la survie, de la croissance, des performances de reproduction des femelles et de la qualité de leur progéniture. Ces meilleures performances s’expliquent par la contribution de la productivité naturelle, estimée entre 37 et 40%, dans l’alimentation de la crevette. Ce complément d’aliment, outre d’être toujours disponible dans le milieu d’élevage, apporte de l’énergie, des nutriments et des molécules bioactives. L’aliment naturel représente une source nutritive de lipides, particulièrement riche en phospholipides et en acides gras polyinsaturés, qui sont essentiels pour la reproduction et le développement des larves en phase de lécitotrophie ; ces lipides sont accumulés dans la glande digestive et les œufs des femelles élevées en biofloc. L’aliment naturel est également une source de glutathion, puissante molécule antioxydante, qui contribue au renforcement du système des défenses anti-radicalaires de la crevette et protège les lipides insaturés de la peroxydation, une cause du stress oxydant. Les bactéries sont prépondérantes dans la productivité naturelle d’un élevage en biofloc et contribuent donc à l’alimentation de la crevette. Aussi, dans le dernier volet de cette thèse, nous avons caractérisé la diversité taxonomique et l’abondance des bactéries du milieu d’élevage et montré son influence sur le microbiote intestinal des crevettes. De façon générale, nous observons une meilleure santé des animaux élevés en biofloc qui se traduit par une régulation positive des gènes impliqués dans l’immunité et les défenses anti-radicalaires après un stress au peroxyde d’hydrogène. Ainsi, les effets positifs de l’élevage en biofloc sur les survies, les croissances et la reproduction ont pour origine le complément d’aliment apporté par la productivité naturelle / Biofloc is an intensive rearing system with zero or minimal water exchange where a diverse population of microorganisms (microalgae, zooplankton and bacteria) develops in association with organic matter to form the floc particles. These particles play the double role of biological filter and dietary supplement. This dissertation aims to better understand the process of this rearing system and its interactions with the Litopenaeus stylirostris shrimp. Two specific objectives were integrated within the framework of this general objective: (i) to measure the production gain from biofloc rearing and (ii) to study the interaction between biofloc environment and shrimp and to assess its role on production performances of shrimps. Thus, our results show production gains of shrimp reared in biofloc in terms of survival, growth, reproductive performances and quality of larvae. This better performance can be explained by the contribution of natural productivity, estimated between 37 and 40%, in shrimp food. This food supplement, constantly available in the environment, provides energy, nutrients and bioactive molecules. The natural productivity represents a source of lipids, in particular of phospholipids and polyunsaturated fatty acids, which were essential for the reproduction and development of larvae during the lecitotrophic stage; these lipids were accumulated in digestive gland and eggs from females reared in biofloc. The natural food is also a glutathione source, a powerful antioxidant molecule, which contributes to strengthen antioxidant defense system of shrimps and protects lipids against peroxidation, a cause of oxidative stress. Bacteria were dominant in natural productivity of biofloc environment and contribute to shrimp food. Thus, in the last part of this dissertation, we characterized the taxonomic diversity and abundance of bacteria in biofloc environment and showed their influence on shrimp intestinal microbiota. Generally, we observed a better health of biofloc resulting in up-regulation of the studied genes involved in immunity and anti-radical defenses after oxidative stress with hydrogen peroxide. The positive effects of biofloc rearing on survival, growth and reproduction originate from food complement provided by natural productivity.
3

Chov ryb v biofloc systému / Fish farming in biofloc system

LUNDA, Roman January 2014 (has links)
The aim of this diploma thesis has been to establish and to verify functionality of a model biofloc system for Nile tilapia (Oreochromis niloticus) farming. The main criteria to be observed during the experiment were chemical characteristcs of the water, development of the biofloc microflora and the reaction of the system to technological interventions. The experiment has consisted of two phases. The first phase monitored an insufficiently functioning system. Due to unsatisfactory assurance of the oxygen concentration as well as the water column stirring, 4 different types of air-sourcing devices have been used in the experiment. For assuring of the perfect stirring and of the sufficient oxygen concentration ( 6 mg×l-1) an airlift fulfilling both the criteria has been constructed. The impact of the carbohydrates application on the decrease of the amonia nitrogen has been sucessfully verified during the experiment. The average value of the C/N ratio of 14 has been reached thanks to the quantity of flour being added as the carbohydrate source into the system. When the recommended amount of TSS (200 ml×l-1) with the corresponding biofloc microflora that has been transforming all the nitrogen in the experiment tank into the microbial protein, the system was evaluated as fully functional. During the biofloc analysis, the presence of N-substances at the amount of 223.6 g at all of the experiment tank (1300 l) has been detected. In the comparison with the applied feed material at the amount of 300 g containing 39% of the N-substances, only 67.1 g of the N-substances has been added into the system. The biofloc (bacterial flakes) serves as food for the tilapia during the entire period of the functional system.
4

Larvicultura do pirarucu em sistema de bioflocos

Dantas, Naiara Silva Menezes, (92) 992409945 28 August 2018 (has links)
Submitted by Naiara Dantas (naiarasmd@hotmail.com) on 2018-09-27T17:44:44Z No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dantas, Naiara Silva Menezes, 2018. Larvicultura do pirarucu em sistema de bioflocos.pdf: 1218709 bytes, checksum: 213b02ee7990da341a78103dd76747b0 (MD5) CartaEncaminhamentoAutodepósito Pedro.pdf: 143442 bytes, checksum: 75844e2eba1a4950b63502ccdb712793 (MD5) ata.pdf: 181412 bytes, checksum: 1015e0dd0d3aecb8e98294006e80a524 (MD5) / Approved for entry into archive by PPGCAN Ciência Animal (ppgcan.ufam@gmail.com) on 2018-09-27T19:45:59Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dantas, Naiara Silva Menezes, 2018. Larvicultura do pirarucu em sistema de bioflocos.pdf: 1218709 bytes, checksum: 213b02ee7990da341a78103dd76747b0 (MD5) CartaEncaminhamentoAutodepósito Pedro.pdf: 143442 bytes, checksum: 75844e2eba1a4950b63502ccdb712793 (MD5) ata.pdf: 181412 bytes, checksum: 1015e0dd0d3aecb8e98294006e80a524 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-09-27T20:33:38Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dantas, Naiara Silva Menezes, 2018. Larvicultura do pirarucu em sistema de bioflocos.pdf: 1218709 bytes, checksum: 213b02ee7990da341a78103dd76747b0 (MD5) CartaEncaminhamentoAutodepósito Pedro.pdf: 143442 bytes, checksum: 75844e2eba1a4950b63502ccdb712793 (MD5) ata.pdf: 181412 bytes, checksum: 1015e0dd0d3aecb8e98294006e80a524 (MD5) / Made available in DSpace on 2018-09-27T20:33:38Z (GMT). No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dantas, Naiara Silva Menezes, 2018. Larvicultura do pirarucu em sistema de bioflocos.pdf: 1218709 bytes, checksum: 213b02ee7990da341a78103dd76747b0 (MD5) CartaEncaminhamentoAutodepósito Pedro.pdf: 143442 bytes, checksum: 75844e2eba1a4950b63502ccdb712793 (MD5) ata.pdf: 181412 bytes, checksum: 1015e0dd0d3aecb8e98294006e80a524 (MD5) Previous issue date: 2018-08-28 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEAM / Arapaima is considered the largest carnivorous species of Amazon and can reach up to 200 kg in the natural environment. Its high market value is due to its fast growth, the peculiar taste of its flesh and the possibilities of use of its byproducts. One of the main challenges of the Arapaima farming is to offer its early stages because there is a high rate of mortality during the larval phase. In this phase, the larvae are usually in the ponds together with the breeding fish, when they are susceptible to parasites, predators and lack of live food. As an alternative, the intensive larviculture allows the control of the environment, creating appropriate conditions for the larvae development. The biofloc technology (BFT) fits this possibility because it provides a better control of the quality of water and pathogens, and the biofloc could be an additional source of food. The objective of this work is to evaluate the performance of the Arapaima larvae reared in BFT. The experimental design was completely randomized with two treatments, a system with clear water (AC) as control and a system of biofloc (BFT), composed of five replication tanks. Arapaima larvae were (0.778 ± 0.02 g and 4.84 ± 0.11 cm) were housed in PVC tanks (20 L; 25 fish per tank). Initially and at the end of the experiment, water were collected and five fish from each treatment were euthanized for microbiological analyzes of the gastrointestinal tract. At the end of the experiment, the water of the BFT was filtered for determination of the proximate composition of the biofloc. There was no significant difference between the performance variables in both treatments; such result was attributed to the inadequate ingestion of food due to the high need of airing for the biofloc floating, causing stress and possibly altering the immunity of the larvae, making them susceptible to pathogenic bacteria; in addition to the elevated levels of nitrogenous compounds, due to the high excretion of the larvae, becoming toxic to the fish. The BFT presented the greatest diversity of bacteria, being identified the genus Aeromonas, Bacillus, Citrobacter, Enterobacter, Hafnia, Klebsiella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Staphylococcus and Yersinia. The biofloc presented 41% of crude protein. Although BFT is an ecologically system for reducing water use and recycling effluents, adjustments are still needed, such as keeping the biofloc at low levels, so that its use is feasible for Arapaima larvicultura. / O pirarucu é considerado a maior espécie carnívora da Amazônia e pode atingir até 200 Kg no ambiente natural. Seu alto valor no mercado deve-se ao bom desempenho zootécnico, sabor peculiar da sua carne e possibilidades para o aproveitamento de seus subprodutos. Um dos maiores desafios da cadeia produtiva do pirarucu é a oferta de formas jovens, pois há um índice elevado de mortalidade durante a fase larval. Geralmente, as larvas ficam nos viveiros junto com os reprodutores, e estão susceptíveis à presença de parasitos, predadores e falta de alimento vivo. Como alternativa, a larvicultura intensiva permite o controle do ambiente criando condições adequadas para o desenvolvimento dos peixes. A tecnologia do BFT se enquadra nesta possibilidade, pois proporciona melhor controle da qualidade de água e patógenos, além do biofloco ser uma fonte adicional de alimento. O objetivo deste trabalho foi avaliar o desempenho zootécnico das larvas de pirarucu no BFT. O desenho experimental foi inteiramente casualizado com dois tratamentos, um sistema com água clara (AC), como controle e, um sistema com a tecnologia bioflocos, composto por cinco repetições (tanques de PVC). Foram selecionadas 250 larvas de pirarucu (0,778 ± 0,02 g e 4,84 ± 0,11 cm) e distribuídas em tanques de PVC (20 L; 25 peixes por tanque). Inicialmente e ao final do experimento, cinco peixes de cada tratamento foram eutanasiados para análises microbiológicas do trato gastrointestinal, assim como amostras de água dos sistemas. Ao final do experimento, a água do BFT foi filtrada para determinação da composição centesimal do floco. Não houve diferença significativa entre as variáveis de desempenho em ambos os tratamentos; atribui-se tal resultado à inadequada ingestão do alimento devido à forte aeração necessária para a flutuabilidade do floco, pois ocasionou estresse e possivelmente alterou a imunidade das larvas, tornando-as susceptíveis a bactérias patogênicas; além dos níveis elevados de compostos nitrogenados, devido à elevada excreção das larvas, tornando-se tóxicos para os peixes. O BFT apresentou a maior diversidade de bactérias dos gêneros Aeromonas, Bacillus, Citrobacter, Enterobacter, Hafnia, Klebsiella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Staphylococcus e Yersinia. Os flocos microbianos apresentaram 41% de Proteína Bruta. Apesar do BFT ser vantajoso ecologicamente por reduzir o uso de águas e reciclar efluentes, ainda são necessários ajustes, como manter o biofloco em níveis baixos, para que seja viável sua utilização para a larvicultura. / Achei tranquilo / Primeiro trabalho com a espécie neste sistema
5

The effects of short-term temperature variations on activated sludge settling

Rossle, Werner Herbert 11 November 2008 (has links)
Settling properties of activated sludge or mixed liquor suspended solids (MLSS) have been studied for more than 75 years at wastewater treatment plants. Temperature, together with MLSS concentration, has been acknowledged as important contributors to MLSS settling variations. Batch MLSS settling tests are performed on a regular basis at most of the plants. The majority of these MLSS settling test reports reflect the complete absence of any form of temperature compensation or even MLSS sample temperature (Ts) recordings. The objective of this study is to evaluate the effects of short-term temperature variations on MLSS settling parameters. This is done by means of simplified theoretical calculations, followed by operational reactor temperature (Tr) observations, and batch MLSS settling tests. The experimental work concludes with the implementation of an on-line MLSS settling test procedure at a full-scale plant reactor to develop settling models based on diurnal Tr fluctuations. These settling models illustrate that parameter correlations improve when Tr is included in on-line MLSS concentration-based settling models. The unhindered settling velocity of a single solid biofloc in water is considered in a simplified calculation to estimate the effect of temperature variations on MLSS settling. Over a Ts increase of 20°C, water density and viscosity reductions result in a calculated biofloc settling velocity increase of less than 0.5 m/hr. Similarly, biofloc density, shape, and size changes result in calculated biofloc settling velocity increases of about 11, 10, and 2 m/hr respectively over the 20°C Ts range. Plant temperature recordings show significant short- to long-term variations. Ambient temperature (Ta) and Tr fluctuate about 20°C and 1.8°C respectively per day, and Tr changes by about 4°C within a week, as measured on-line at local plants during the test period in winter. The aeration method can have a significant impact on Tr. Differences in Tr in adjacent surface and bubble aeration reactors in the same plant were about 5°C. Large enough Tr and Ta variations exist at these local plants to affect MLSS settling test results. The MLSS settling test cylinder environment and meteorological conditions have a direct influence on Ts during batch settling tests. Direct solar radiation increases the average Ts by 4.3°C, or by 0.15°C per minute, during a 30-minute MLSS settling test duration. This Ts change leads to a sludge volume index (SVI) change of 63 mℓ/g, at an average SVI decrease of 14.8 mℓ/g per 1°C Ts increase. Changes to other parameters include an initial settling velocity (ISV) increase of about 0.12 m/hr for every 1°C Ts increase, together with a clarified supernatant turbidity increase of about 1.4 formazine nephelometric unit (FNU) for every 1°C Ts increase. Ts adjusts towards Ta before and during a batch MLSS settling test, thereby influencing MLSS settling results. Compensation for Ts variations during routine MLSS settling tests is nevertheless not reported as a common practice. To some extent, this is due to a lack of temperature-controlled MLSS settling test equipment. An automated MLSS settling meter demonstrates a semi-continuous on-line method to determine settling parameters in situ at the operational Tr of a full-scale plant. A basic polynomial fits 11 MLSS settling parameters that indicate in most instances improved MLSS settling at increased Tr. The average SVI decreases by 14.8 mℓ/g for every 1°C Tr increase. Similarly, for every 1°C Tr increase, the maximum settling velocity (u_max) increase is 0.1 m/hr, and the time to reach maximum settling velocity (t_umax) decreases by 2.4 minutes. The incremental 5-minute duration average settling velocities increase over the first 15 minutes of a MLSS settling test, as the MLSS concentration decreases and the Tr increases. This direct incremental settling velocity trend with Tr is reversed between 15 and 30 minutes, as the average 5-minute MLSS settling velocity increases at a reduced Tr. The inclusion of Tr in MLSS concentration-based settling best-fit correlations with SVI, u_max, and t_umax improves the coefficient of multiple determinations (R2) by an average of 0.32. Best-fit SVI models with u_max and t_umax have R2-values of 0.90 and 0.95 respectively. The developed models are only valid for the individual reactor MLSS conditions within the experimental parameter ranges. The main contribution of this study is to present temperature-based MLSS settling models. These models illustrate that an automated on-line MLSS settling meter is suitable to identify and model temperature related MLSS settling data with minimal experimental effort. A suitable approach is provided to improve the reliability of MLSS settling data, as effects of short-term temperature variations can be practically eliminated from settling test. / Thesis (PhD)--University of Pretoria, 2008. / Chemical Engineering / unrestricted
6

Sustainable Shrimp Production: A Technology Feasibility Analysis through an Operational &amp; Environmental Perspective

chrysochoou, christos January 2022 (has links)
To be able to satisfy current society’s needs without compromising future generations to satisfy their needs, is the key to sustainability. Many old practices and methods have had negative impact on the environment, including food production &amp; cultivation activities with aquaculture being one of them. A growing population and environmental pollution, demand new technologies to be developed, to ensure food supply but also not to harm the environment at the same time. Such technologies have been developed the last decades allowing for indoor farming of aquaculture species including shrimp. Shrimps are popular all over the world and their demand is continuously increasing. This thesis focuses on two different technologies that primarily aim to grow shrimps in the most effective way with reduced demand of natural and chemical resources considering sustainability. One technology is Biofloc, and the other is the Recirculated Aquaculture System (RAS). A multicriteria Decision Analysis (MCDA) will take place in this thesis to compare the two alternative technologies based on a few criteria. The criteria used, derive from two categories, operational and environmental, and this thesis aims to understand the pros and cons of each technology with respect to sustainability.
7

Produção e transporte do camarão rosa Farfantepenaeus brasiliensis para a pesca amadora: uma alternativa sustentável?

Vaz, Luciano Jensen 30 May 2012 (has links)
Made available in DSpace on 2016-06-02T19:29:53Z (GMT). No. of bitstreams: 1 4559.pdf: 2430892 bytes, checksum: d154b35d326d05be2db06928cf07eaa6 (MD5) Previous issue date: 2012-05-30 / Financiadora de Estudos e Projetos / As well as being popular and growing worldwide, sport fisheries are considered an important recreational, economic and social activity that propels a wide production chain and generates employment and income. The major species of marine shrimp used as live bait in the Brazilian coast used as live bait in sport fishing are: white shrimp Litopenaeus schmitti and pink shrimp Farfantepenaeus brasiliensis and Farfantepenaeus paulensis, all of them included in the list of overexploited species. Although the shrimp are caught in estuaries throughout the year, the main period of capture occurs in the summer months. This fact produces significant fluctuations in the catch throughout the year, occurring in situations that greatly reduced catches. In view of these facts, the cultivation of shrimps for bait production could become an important tool for conservation and regulation of the market for live bait. Thus, the studies that comprise this thesis were directed to the production of pink shrimp F. brasiliensis in biofloc system and management studies related to transportation of shrimp as live bait. From the results observed in thesis, it was observed that there is already a well established method for the production of post-larvae of F. brasiliensis this phase is not an obstacle for the production of live bait. Furthermore, the results show that F. brasiliensis has a potential for the cultivation in biofloc system and can be reared in a stocking density of up to 100 shrimp/m² during the nursery stage and in a density of up to 75 shrimp/m² during the grow-out phase. Finally, it was observed that for the transport of F. brasiliensis the water temperature should be between 16 and 19 °C and stocking density should not exceed 3 shrimp / L or (16.5 g / L), the transport is recommended for a maximum of 10 hours to prevent mortality. Therefore, according to all data obtained in this thesis, post-larvae production, cultivation in biofloc system and transportation of F. brasiliensis to be used as live bait proved to be technically viable solutions to meet the needs of sport fisheries. / Além de popular e crescente no mundo todo, a pesca amadora é considerada uma importante atividade recreativa, econômica e social que movimenta uma ampla cadeia produtiva gerando emprego e renda. As principais espécies de camarões marinhos nativos da costa brasileira utilizados como isca viva na pesca amadora são: o camarão-branco Litopenaeus schmitti e os camarões-rosa Farfantepenaeus brasiliensis e Farfantepenaeus paulensis, todas incluídas na lista de espécies sobre-explotadas. Embora os camarões sejam capturados em estuários ao longo de todo o ano, o principal período de captura ocorre nos meses de verão. Este fato produz flutuações significativas na captura ao longo do ano, ocorrendo situações em que as capturas diminuem muito. Em vista destes fatos, o cultivo de camarões para produção de iscas vivas pode vir a ser um importante instrumento para a conservação e para regulação do mercado de isca viva. Portanto, os estudos que compõem esta tese foram direcionados para a produção do camarão-rosa F. brasiliensis em sistema de bioflocos e para estudos de manejo relacionados ao transporte destes camarões como isca viva. A partir dos resultados observados na tese, pode se verificar que já existe uma metodologia bem estabelecida para a produção de pós-larvas de F. brasiliensis não sendo esta fase um obstáculo para a produção de isca viva. Além disso, os resultados mostraram que F. brasiliensis apresenta um potencial para o cultivo em sistema de bioflocos podendo ser cultivado na densidade de estocagem de até 100 camarões/m2 durante a fase de berçário e até 75 camarões/m2 durante a fase de engorda. Por último, observou-se que para o transporte de F. brasiliensis a temperatura da água deve estar entre 16 e 19 °C e a densidade de estocagem não deve ultrapassar os 3 camarões/L ou (16,5 g/L), sendo recomendado o transporte por no máximo 10 horas para evitar mortalidades. Portanto, de acordo com os dados obtidos na presente tese, a produção de pós-larvas, o cultivo em sistema de bioflocos e o transporte de F. brasiliensis para a comercialização na forma de isca viva para suprir as necessidades da pesca amadora demonstrou ser tecnicamente viável.
8

The Development of Marine Aquaponics

Yu-Ting Chu (11777624) 01 December 2021 (has links)
Integrated aquaponic food production systems are capable of producing more food on less land using less water than conventional food systems, and marine systems offer the potential of conserving freshwater resources. However, critical factors such as suitable species combinations, environmental conditions (salinity and pH), and nutrient management (animal to plant ratio, C/N ratio, and dietary crude protein) have not been fully understood for marine systems. There were four objectives in this project. The first objective was to evaluate the growth performance of potential comparable combination (whiteleg shrimp with three halophytic plants) for the development of marine aquaponics with BFT under different salinities. The second objective was to evaluate stocking densities and the C/N ratio on growth and production of whiteleg shrimp and three halophytes. The third objective was evaluation of varying concentrations of dietary crude protein in practical diets fed to shrimp raised in biofloc aquaponic saltwater systems. The fourth objective was to evaluate effects of pH levels and additional C on the growth and production of whiteleg shrimp and five plant species in marine aquaponics. Four conclusions were determined: 1) Regarding marine aquaponics, whiteleg shrimp and the three halophytes (Atriplex hortensis, Salsola komarovii, and Plantago coronopus) are suitable combinations for future development. According to the research results, shrimp performed better in a salinity of 15 and 20 ppt; yet, plants performed better in a salinity of 10 and 15 ppt. Therefore, a salinity of 15 ppt is suggested as the optimal saline condition for shrimp and the three halophytes in an indoor marine aquaponics system. In addition, inoculating probiotics do have the efficiency of stabilizing water quality, cultivating microbial community, and enhancing the health of shrimp and plants in the operation of aquaponics. 2) The stocking density ratio and C/N ratio exerted significant impacts on the performance of shrimp and plants in marine aquaponics. Shrimp performed better with the stocking density of 2:1 and 3:1, with no impact from the C/N ratio. Conversely, plants performed better with the stocking density of 3:1 and 5:1 with the C/N ratio at 15. Therefore, a stocking density ratio of 3:1 with a C/N ratio at 15 is suggested as the optimal condition for shrimp and the three halophytes in an indoor marine aquaponic food production system. Inoculating the water with biofloc and applying probiotics regularly can enhance the management of water quality and the health of shrimp and plants in aquaponics. 3) Among the findings of the study, shrimp growth was not affected by the protein content of the feed, suggesting that it is possible to use feeds with lower protein concentration when culturing shrimp in biofloc-based marine aquaponics. However, plants grew better in the treatments with higher protein content feed in the early and middle stages of production. Hence, for maximum production, providing a higher protein concentration feed (35 %) in the early stages of system start-up, and switching to a lower protein concentration feed (30 %) in the later stages of cultivation might be feasible. 4) The current study found no significant effects of pH or additional C on shrimp performance. In contrast, plants grew better in lower pH treatments, while additional C supplements improved the performance of plants grown in higher pH treatments and had similar results to the lower pH treatments. We suggest that RO water is not suitable source of water for shrimp-based marine aquaponics if ionic composition is not managed. The addition of C, however, led to improved growth and yields of most plants. Hence, adding C can be a promising approach in marine aquaponics to enhance the resistance to the abiotic stress of plants and improve their growth.<div> <br>The present study on marine aquaponics has produced important findings that will fill some knowledge gaps, provide management guidelines for production, and facilitate its development. <br></div>

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