WorldWideScience

Sample records for aquaculture enclosures relate

  1. Modeling of humidity-related reliability in enclosures with electronics

    DEFF Research Database (Denmark)

    Hygum, Morten Arnfeldt; Popok, Vladimir

    2015-01-01

    Reliability of electronics that operate outdoor is strongly affected by environmental factors such as temperature and humidity. Fluctuations of these parameters can lead to water condensation inside enclosures. Therefore, modelling of humidity distribution in a container with air and freely exposed...

  2. Contact zoonosis related to aquaculture: a growing concern

    Science.gov (United States)

    Aquaculture develops fast worldwide, with new cultured species and increased global transport of live aquaculture products. There is a growing recognition of zoonotic disease agents causing epidemics and carrier states in cultured fish and shellfish, especially from warm water systems, transmitted t...

  3. Macrobenthos off Mahim (Bombay), west coast of India in relation to coastal pollution and aquaculture

    Digital Repository Service at National Institute of Oceanography (India)

    Varshney, P.K.; Govindan, K.

    -1 MACROBENTHOS OFF MAHIM (BOMBAY), WEST COAST OF INDIA IN RELATION TO COASTAL POLLUTION AND AQUACULTURE P. K. VARSHNEY AND K GOVINDAN* Central Institute of Fisheries Education, Chinhat Centre, Lucknow - 227 105 ABSTRACT Deterioration of water quality clearly.... D. Tripathi, Director, Central Institute of Fisheries Education, Bombay for permission to present the same to this seminar. REFERENCES Dwivedi, S. N. and Desai, B. N. 1972. Marine food resources and conservation along the west coast of India...

  4. The aquaculture potential of Tilapia rendalli in relation to its feeding habits and digestive capabilities

    Science.gov (United States)

    Hlophe, S. N.; Moyo, N. A. G.

    Tilapia rendalli is a predominately macrophagous fish. However, it was able to colonise an oligotrophic dam (Flag Boshielo) with limited macrophytes. Therefore, the diet of T. rendalli in this dam was investigated; its stomach contents were examined over 12 months. A size related dietary shift was evident. Juveniles fed mainly on zooplankton while sub-adult and adult fish grazed on both macrophytes and marginal vegetation. T. rendalli’s ability to strive in an environment with limited food resources led to a subsequent study to determine its aquaculture potential. Its growth performance was compared to that of the commonly cultured Oreochromis mossambicus. Juveniles of both species were fed a commercial tilapia diet for 60 days. Specific growth rate and protein efficiency ratio was comparable to that of O. mossambicus (P > 0.05, ANOVA). Feed conversion ratio was significantly higher (P 0.05). Amylase activities were significantly higher (P < 0.05) in T. rendalli than in O. mossambicus. The highest amylase activities were recorded in the proximal intestines as 26.34 and 22.00 μmol/min/mg protein in T. rendalli and O. mossambicus respectively. This may be an indicator that T. rendalli is better equipped to digest plant diets. T. rendalli may be the aquaculture species of choice for emerging fish farmers who cannot afford the highly priced fishmeal as a protein source in fish diets.

  5. Epidemiological aspects of aquaculture in relation to fish borne trematodiasis in Malaysia.

    Science.gov (United States)

    Shekhar, K C

    1997-01-01

    Epidemiological studies have been conducted to determine the association between fish and disease. The fish were obtained from rivers, streams, ponds and lakes but few from aquaculture farms. While no defined studies have been carried out in Malaysia, baseline data show that fish obtained from aquaculture farms (mixed farming) contributed to cases of opisthorchiasis and clonorchiasis.

  6. Ocean Colour Products from Remote Sensing Related to In-Situ Data for Supporting Management of Offshore Aquaculture

    Science.gov (United States)

    Fragoso, Bruno Dias Duarte; Icely, John; Moore, Gerald; Laanen, Marnix; Ghbrehiwot, Semhar

    2016-08-01

    The EU funded "AQUAculture USEr driven operational Remote Sensing information services project" (AQUA- USERS grant number 607325) is a user driven project for the aquaculture industry that aims at providing this industry with relevant and timely information based on the most recent satellite data and innovative optical in- situ measurements. The Water Insight Spectrometer (WISP-3) is a hand held instrument which can provide measurements of the optical parameters Chlorophyll-a (Chl-a), Total Suspended Matter (TSM), Coloured Dissolved Organic Matter (CDOM), and the Spectral Diffuse Attenuation Coefficient (Kd). Sampling campaigns were carried out between March 2014 and September 2015, to collect water samples at the same time as taking optical reading from the WISP-3 at an offshore aquaculture site off Sagres on the SW Portugal, operated by Finisterra Lda, one of the "users" in the project. The estimates from the WISP-3 for Chla and TSM have been compared with in-situ measurements from the water samples for these two variables, with the objective of calibrating the algorithms used by the WISP-3 for estimation of Chla and TSM. At a later stage in the project, it is expected that WISP-3 readings can be related to remote sensing products developed from the Ocean Land Coloured Instrument (OLCI) from the Sentinel-3 satellite. The key purpose of AQUA- Users is to develop, in collaboration with "users" from the aquaculture industry, a mobile phone application (app) that collates satellite information on optical water quality and temperature together with in-situ data of these variables to develop a decision support system for daily management of the aquaculture.

  7. Aquaculture, Capture Fisheries, and Wild Fish Stocks

    OpenAIRE

    Shan Jiang

    2007-01-01

    In a general equilibrium model, this paper examines how the rise of aquaculture and the decline of wild fish stocks are related. Two factors, population growth and technological improvement in aquaculture, have been studied in an aquaculture restricted entry case and an aquaculture free entry case. Both factors raise aquaculture production, while changes in wild fish stocks hinge on entry conditions. In the restricted entry case, population growth reduces wild fish stocks, but technological p...

  8. Impacts, Perceptions and Management of Climate-Related Risks to Cage Aquaculture in the Reservoirs of Northern Thailand

    Science.gov (United States)

    Lebel, Louis; Lebel, Phimphakan; Lebel, Boripat

    2016-12-01

    Weather is suspected to influence fish growth and survival, and be a factor in mass mortality events in cage aquaculture in reservoirs. The purpose of this study was to identify the important climate-related risks faced by cage aquaculture farms; evaluate how these risks were currently being managed; and explore how farmers might adapt to the effects of climate change. Fish farmers were interviewed across the northern region of Thailand to get information on impacts, perceptions and practices. Drought or low water levels, heat waves, cold spells and periods with dense cloud cover, each caused significant financial losses. Perceptions of climate-related risks were consistent with experienced impacts. Risks are primarily managed in the short-term with techniques like aeration and reducing feed. In the mid-term farmers adjust stocking calendars, take financial measures and seek new information. Farmers also emphasize the importance of maintaining good relations with other stakeholders and reservoir management. Larger farms placed greater importance on risk management than small farms, even though types and levels of risk perceived were very similar. Most fish farms were managed by men alone, or men and women working together. Gender differences in risk perception were not detected, but women judged a few risk management practices as more important than men. Fish farmers perceived that climate is changing, but their perceptions were not strongly associated with recently having suffered impacts from extreme weather. The findings of this study provide important inputs to improving risk management under current and future climate.

  9. Aquaculture; Acquacoltura

    Energy Technology Data Exchange (ETDEWEB)

    De Murtas, I.D. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1998-12-01

    This paper attempts an overview of the progress made in the field of aquaculture. Aquaculture is a system of techniques strongly influenced by natural environmental conditions. Aquaculture as a biological technique oriented towards the production of useful aquatic organisms, is reaching a stage of consolidation which will place it on an equal footing which agriculture and animal husbandry. Aquaculture provides important economic and nutritional benefits to many regions of developing world. In 1994, over 90 percent of total aquaculture production was in Asia, with China, India, Japan, Indonesia, Thailand, Philippines and Republic of Korea as the seven leader producers. [Italiano] L`acquacoltura, vale a dire l`arte di riprodurre artificialmente pesci, alghe, molluschi e crostacei ed altri organismi acquatici utili all`uomo, si presenta oggi come un`attivita` di assoluto rilievo nell`insieme dei vari comparti di produzione alimentare. L`aumento della produzione e` costante anche se cinque paesi asiatici (Cina, India, Giappone, Filippine e Corea del Sud) contribuiscono per l`80% al volume della produzione mondiale. Nel presente lavoro vengono descritti lo stato dell`acquacoltura e della maricoltura nel mondo e le filiere di allevamento delle principali specie.

  10. Abundance of plankton population densities in relation to bottom soil textural types in aquaculture ponds

    Directory of Open Access Journals (Sweden)

    F. Siddika

    2012-06-01

    Full Text Available Plankton is an important food item of fishes and indicator for the productivity of a water body. The present study was conducted to evaluate the effects of bottom soil textural conditions on abundance of plankton in aquaculture pond. The experiment was carried out using three treatments, i.e., ponds bottom with sandy loam (T1, with loam (T2 and with clay loam (T3. The ranges of water quality parameters analyzed were suitable for the growth of plankton during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed higher ranges in T2. A total 20 genera of phytoplankton were recorded belonged to Chlorophyceae (7, Cyanophyceae (5, Bacillariophyceae (5, Euglenophyceae (2 and Dinophyceae (1. On the other hand, total 13 genera of zooplankton were recorded belonged to Crustacea (7 and Rotifera (6. The highest ranges of phytoplankton and zooplankton densities were found in T2 where low to medium-type bloom was observed during the study period. Consequently, the mean abundance of plankton (phytoplankton and zooplankton density was significantly highest in T2. The highest abundance of plankton in the T2 indicated that pond bottom with loamy soil is suitable for the growth and production of plankton in aquaculture ponds.

  11. Abundance of macrozoobenthos in relation to bottom soil textural types and water depth In aquaculture ponds

    Directory of Open Access Journals (Sweden)

    N. Nupur

    2013-12-01

    Full Text Available The present experiment was conducted to evaluate the effects of bottom soil textural classes and different water depths on abundance of macrozoobenthos in aquaculture ponds. Three treatments, i.e., ponds bottom with sandy loam (T1, with loam (TS2 and with clay loam (T3 were considered in this experiment. Samples were collected from three different depths (60.96 cm, 106.68 cm and 152.40 cm with three replications. The ranges of water quality parameters were suitable for the growth of macrozoobenthos during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed comparatively higher ranges in T2. Eight genera were recorded belonging to major groups of Chironomidae, Oligochaeta, Mollusca and Ceratoponogonidae. The highest population densities of Oligochaeta (1200±4.25 per m2, Chironomidae (1422±4.88 per m2, Ceratopogonidae (399±1.56 per m2 and Mollusca (977±2.24 per m2 were found in T2. The population densities of macrozoobenthos showed fortnightly variations in all the treatments. Among the three depths, significantly highest densities of macrozoobenthos were recorded in 106.68 cm in every treatment. The mean abundance of macrozoobenthos was significantly highest in T2. The present study indicates that loamy soil pond bottom along with water depth 106.68 cm is suitable for the growth and production of macrozoobenthos in aquaculture ponds.

  12. World aquaculture: environmental impacts and troubleshooting alternatives.

    Science.gov (United States)

    Martinez-Porchas, Marcel; Martinez-Cordova, Luis R

    2012-01-01

    Aquaculture has been considered as an option to cope with the world food demand. However, criticisms have arisen around aquaculture, most of them related to the destruction of ecosystems such as mangrove forest to construct aquaculture farms, as well as the environmental impacts of the effluents on the receiving ecosystems. The inherent benefits of aquaculture such as massive food production and economical profits have led the scientific community to seek for diverse strategies to minimize the negative impacts, rather than just prohibiting the activity. Aquaculture is a possible panacea, but at present is also responsible for diverse problems related with the environmental health; however the new strategies proposed during the last decade have proven that it is possible to achieve a sustainable aquaculture, but such strategies should be supported and proclaimed by the different federal environmental agencies from all countries. Additionally there is an urgent need to improve legislation and regulation for aquaculture. Only under such scenario, aquaculture will be a sustainable practice.

  13. Aquaculture report 1976

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D.K.; Watson, L.; Kent, J.C.; Johnson, D.W.

    1977-04-08

    Growth of channel catfish (Ictalurus punctatus) and Tilapia zillii in the Reft River Geothermal Area (RRGT) geothermal waters can equal or surpass that in a commercial aquaculture facility. Fish and prawn mortality over the course of the intermediate term preliminary study did not appear to be related to any inherent geothermal water chemistry conditions. Temperature control was a problem but does not appear to be beyond design control. The absence of temperature-related mortality in channel catfish, Tilapia zilli, and yellow perch (Perca flavescens) indicates increased survival and suggests reduced expenditures for disease control. It may also allow higher fish densities in commercial aquaculture operations using geothermal water. Results of this study indicate potential for commercial aquaculture development at the Raft River Geothermal Testing Site.

  14. Fire Research Enclosure

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Simulates submarine fires, enclosed aircraft fires, and fires in enclosures at shore facilities .DESCRIPTION: FIRE I is a pressurizable, 324 cu m(11,400 cu...

  15. VIRUS instrument enclosures

    Science.gov (United States)

    Prochaska, T.; Allen, R.; Mondrik, N.; Rheault, J. P.; Sauseda, M.; Boster, E.; James, M.; Rodriguez-Patino, M.; Torres, G.; Ham, J.; Cook, E.; Baker, D.; DePoy, Darren L.; Marshall, Jennifer L.; Hill, G. J.; Perry, D.; Savage, R. D.; Good, J. M.; Vattiat, Brian L.

    2014-08-01

    The Visible Integral-Field Replicable Unit Spectrograph (VIRUS) instrument will be installed at the Hobby-Eberly Telescope† in the near future. The instrument will be housed in two enclosures that are mounted adjacent to the telescope, via the VIRUS Support Structure (VSS). We have designed the enclosures to support and protect the instrument, to enable servicing of the instrument, and to cool the instrument appropriately while not adversely affecting the dome environment. The system uses simple HVAC air handling techniques in conjunction with thermoelectric and standard glycol heat exchangers to provide efficient heat removal. The enclosures also provide power and data transfer to and from each VIRUS unit, liquid nitrogen cooling to the detectors, and environmental monitoring of the instrument and dome environments. In this paper, we describe the design and fabrication of the VIRUS enclosures and their subsystems.

  16. Fire Research Enclosure

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Simulates submarine fires, enclosed aircraft fires, and fires in enclosures at shore facilities . DESCRIPTION: FIRE I is a pressurizable, 324 cu m(11,400...

  17. Safety in Aquaculture

    Science.gov (United States)

    Durborow, Robert M.; Myers, Melvin L.

    2016-01-01

    In this article, occupational safety interventions for agriculture-related jobs, specifically in aquaculture, are reviewed. Maintaining quality of life and avoiding economic loss are two areas in which aquaculturists can benefit by incorporating safety protocols and interventions on their farms. The information in this article is based on farm…

  18. Aquaculture Information Package

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, T.; Rafferty, K. [editors

    1998-01-01

    This package of information is intended to provide background to developers of geothermal aquaculture projects. The material is divided into eight sections and includes information on market and price information for typical species, aquaculture water quality issues, typical species culture information, pond heat loss calculations, an aquaculture glossary, regional and university aquaculture offices and state aquaculture permit requirements.

  19. MROI Array telescopes: the relocatable enclosure domes

    Science.gov (United States)

    Marchiori, G.; Busatta, A.; Payne, I.

    2016-07-01

    The MROI - Magdalena Ridge Interferometer is a project which comprises an array of up to 10 1.4m diameter mirror telescopes arranged in a "Y" configuration. Each of these telescopes will be housed inside a Unit Telescope Enclosure (UTE) which are relocatable onto any of 28 stations. EIE GROUP Srl, Venice - Italy, was awarded the contract for the design, the construction and the erection on site of the MROI by the New Mexico Institute of Mining and Technology. The close-pack array of the MROI - including all 10 telescopes, several of which are at a relative distance of less than 8m center to center from each other - necessitated an original design for the Unit Telescope Enclosure (UTE). This innovative design enclosure incorporates a unique dome/observing aperture system to be able to operate in the harsh environmental conditions encountered at an altitude of 10,460ft (3,188m). The main characteristics of this Relocatable Enclosure Dome are: a Light insulated Steel Structure with a dome made of composites materials (e.g. glass/carbon fibers, sandwich panels etc.), an aperture motorized system for observation, a series of louvers for ventilation, a series of electrical and plants installations and relevant auxiliary equipment. The first Enclosure Dome is now under construction and the completion of the mounting on site id envisaged by the end of 2016. The relocation system utilizes a modified reachstacker (a transporter used to handle freight containers) capable of maneuvering between and around the enclosures, capable of lifting the combined weight of the enclosure with the telescope (30tons), with minimal impacts due to vibrations.

  20. Aquaculture information package

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, T.; Rafferty, K.

    1998-08-01

    This package of information is intended to provide background information to developers of geothermal aquaculture projects. The material is divided into eight sections and includes information on market and price information for typical species, aquaculture water quality issues, typical species culture information, pond heat loss calculations, an aquaculture glossary, regional and university aquaculture offices and state aquaculture permit requirements. A bibliography containing 68 references is also included.

  1. Humidity Buildup in Electronic Enclosures Exposed to Constant Conditions

    DEFF Research Database (Denmark)

    Conseil, Helene; Staliulionis, Zygimantas; Jellesen, Morten Stendahl

    2017-01-01

    parameters such as openings in the enclosure (drain holes, intentional openings or leak) and sealing and casing material. Related corrosion reliability issues due to humidity buildup have been evaluated using an interdigitated surface insulation resistance pattern placed inside the enclosure during exposure...

  2. Marketing netcoatings for aquaculture.

    Science.gov (United States)

    Martin, Robert J

    2014-10-17

    Unsustainable harvesting of natural fish stocks is driving an ever growing marine aquaculture industry. Part of the aquaculture support industry is net suppliers who provide producers with nets used in confining fish while they are grown to market size. Biofouling must be addressed in marine environments to ensure maximum product growth by maintaining water flow and waste removal through the nets. Biofouling is managed with copper and organic biocide based net coatings. The aquaculture industry provides a case study for business issues related to entry of improved fouling management technology into the marketplace. Several major hurdles hinder entry of improved novel technologies into the market. The first hurdle is due to the structure of business relationships. Net suppliers can actually cut their business profits dramatically by introducing improved technologies. A second major hurdle is financial costs of registration and demonstration of efficacy and quality product with a new technology. Costs of registration are prohibitive if only the net coatings market is involved. Demonstration of quality product requires collaboration and a team approach between formulators, net suppliers and farmers. An alternative solution is a vertically integrated business model in which the support business and product production business are part of the same company.

  3. Distribution patterns of macrobenthic species in relation to organic enrichment within aquaculture earthen ponds.

    Science.gov (United States)

    Carvalho, Susana; Barata, Marisa; Pereira, Fábio; Gaspar, Miguel B; Cancela da Fonseca, Luís; Pousão-Ferreira, Pedro

    2006-12-01

    The relationship between organic enrichment and macrobenthic colonization patterns was investigated during an 8-month period in Diplodus sargus (white seabream) production ponds. A stratified sampling design was applied and each pond was divided into three zones: water entrance (WE); central (C); and automatic feeder zones (AF). Generally, the number of species and Shannon-Wiener diversity increased from the WE to the AF zone. Abundance did not present a clear trend. The recently developed marine biotic index (AMBI) was applied and showed to be sufficiently robust to discriminate, within a relatively small area, differences in macrobenthic communities due to organic enrichment. Nevertheless, caution is advised when applying this index or others based on ecological group's assignment, as the classification of a certain area may differ when allocating a certain species to an unsuitable group. This is particularly evident when common species are involved.

  4. British Columbia's fish health regulatory framework's contribution to sustainability goals related to salmon aquaculture.

    Science.gov (United States)

    Stephen, Craig; Dicicco, Emiliano; Munk, Brandon

    2008-12-01

    Salmon farming is a significant contribution to the global seafood market to which the goal of sustainability is often applied. Diseases related to farms are perhaps the most contentious issues associated with sustainable salmon farming. We reviewed literature and policies in British Columbia, Canada, as well as interviewed key informants to examine how fish health regulations do or could support sustainability goals. We found four main obstacles to the development and application of a sustainability-based health management system. First, salmon farming faced the same challenges as other industries when trying to establish an operational definition of sustainability that captures all stakeholders' interests. Second, there was no program responsible for integrating the various regulations, responsible departments, and monitoring efforts to develop a comprehensive view of sustainability. Third, there was inadequate research base and social consensus on the criteria that should be used to track health outcomes for sustainability purposes. Fourth, the regulatory and management paradigm for salmon farming has been focused on diseases and pathogens as opposed to embracing a more inclusive health promotion model that includes biotic, abiotic, and social determinants of health. A transparent and inclusive participatory process that effectively links expert views with community and industry concerns should serve as the foundation for the next generation of health management regulations for salmon farming.

  5. All about Aquaculture.

    Science.gov (United States)

    Brody, Michael J.; Patterson, B. Patricia

    1992-01-01

    Describes a sequence of activities in which students set up a classroom aquarium to learn about aquaculture. Discusses the aquarium system, filtration and maintenance, adding organisms to the system, technological considerations, aquaculture economics, and political and social aspects of aquaculture. (MDH)

  6. World Aquaculture: Environmental Impacts and Troubleshooting Alternatives

    Directory of Open Access Journals (Sweden)

    Marcel Martinez-Porchas

    2012-01-01

    Full Text Available Aquaculture has been considered as an option to cope with the world food demand. However, criticisms have arisen around aquaculture, most of them related to the destruction of ecosystems such as mangrove forest to construct aquaculture farms, as well as the environmental impacts of the effluents on the receiving ecosystems. The inherent benefits of aquaculture such as massive food production and economical profits have led the scientific community to seek for diverse strategies to minimize the negative impacts, rather than just prohibiting the activity. Aquaculture is a possible panacea, but at present is also responsible for diverse problems related with the environmental health; however the new strategies proposed during the last decade have proven that it is possible to achieve a sustainable aquaculture, but such strategies should be supported and proclaimed by the different federal environmental agencies from all countries. Additionally there is an urgent need to improve legislation and regulation for aquaculture. Only under such scenario, aquaculture will be a sustainable practice.

  7. World Aquaculture: Environmental Impacts and Troubleshooting Alternatives

    Science.gov (United States)

    Martinez-Porchas, Marcel; Martinez-Cordova, Luis R.

    2012-01-01

    Aquaculture has been considered as an option to cope with the world food demand. However, criticisms have arisen around aquaculture, most of them related to the destruction of ecosystems such as mangrove forest to construct aquaculture farms, as well as the environmental impacts of the effluents on the receiving ecosystems. The inherent benefits of aquaculture such as massive food production and economical profits have led the scientific community to seek for diverse strategies to minimize the negative impacts, rather than just prohibiting the activity. Aquaculture is a possible panacea, but at present is also responsible for diverse problems related with the environmental health; however the new strategies proposed during the last decade have proven that it is possible to achieve a sustainable aquaculture, but such strategies should be supported and proclaimed by the different federal environmental agencies from all countries. Additionally there is an urgent need to improve legislation and regulation for aquaculture. Only under such scenario, aquaculture will be a sustainable practice. PMID:22649291

  8. Stringency of environmental regulation and aquaculture growth

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw; Nielsen, Rasmus; Tveterås, Ragnar

    2016-01-01

    During the last three decades, aquaculture has been the fastest growing animal-food-producing sector in the world, accounting for half of the present seafood supply. However, there is a significant growth disparity among aquaculture-producing countries. The reasons why some countries have achieved...... remarkable growth in aquaculture while others have stagnated or even declined have not been determined. In this article, we investigate whether environmental regulations have an impact on aquaculture growth. Using a cross-country regression analysis, we show that stringent environmental regulations...... are negatively related to aquaculture growth, whereas GDP growth has a positive effect. Countries often face a difficult balancing act between growth and environmental considerations when devising regulations. Our empirical results suggest that stricter environmental regulations in developed countries have...

  9. BIOFILTERS IN AQUACULTURE

    OpenAIRE

    2010-01-01

    Recirculating aquaculture is one of the solutions to an environmentally sustainable and economically feasible aquaculture production, and can be established in either urban or rural communities. Controlled conditions enable optimal growth conditions suitable for the species in question during the whole growth process, as well as the shortening of the process itself, when compared to open uncontrolled systems. Recirculating systems are now one of the most researched fields of aquaculture, and ...

  10. Chemicals for worldwide aquaculture

    Science.gov (United States)

    Schnick, R.A.

    1991-01-01

    Regulations and therapeutants or other safe chemicals that are approved or acceptable for use in the aquaculture industry in the US, Canada, Europe and Japan are presented, discussing also compounds that are unacceptable for aquaculture. Chemical use practices that could affect public health are considered and details given regarding efforts to increase the number of registered and acceptable chemicals.

  11. Safety of Hydrogen Systems Installed in Outdoor Enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Barilo, Nick F.

    2013-11-06

    The Hydrogen Safety Panel brings a broad cross-section of expertise from the industrial, government, and academic sectors to help advise the U.S. Department of Energy’s (DOE) Fuel Cell Technologies Office through its work in hydrogen safety, codes, and standards. The Panel’s initiatives in reviewing safety plans, conducting safety evaluations, identifying safety-related technical data gaps, and supporting safety knowledge tools and databases cover the gamut from research and development to demonstration and deployment. The Panel’s recent work has focused on the safe deployment of hydrogen and fuel cell systems in support of DOE efforts to accelerate fuel cell commercialization in early market applications: vehicle refueling, material handling equipment, backup power for warehouses and telecommunication sites, and portable power devices. This paper resulted from observations and considerations stemming from the Panel’s work on early market applications. This paper focuses on hydrogen system components that are installed in outdoor enclosures. These enclosures might alternatively be called “cabinets,” but for simplicity, they are all referred to as “enclosures” in this paper. These enclosures can provide a space where a flammable mixture of hydrogen and air might accumulate, creating the potential for a fire or explosion should an ignition occur. If the enclosure is large enough for a person to enter, and ventilation is inadequate, the hydrogen concentration could be high enough to asphyxiate a person who entered the space. Manufacturers, users, and government authorities rely on requirements described in codes to guide safe design and installation of such systems. Except for small enclosures used for hydrogen gas cylinders (gas cabinets), fuel cell power systems, and the enclosures that most people would describe as buildings, there are no hydrogen safety requirements for these enclosures, leaving gaps that must be addressed. This paper proposes that

  12. Plasmid-related quinolone resistance determinants in epidemic Vibrio parahaemolyticus, uropathogenic Escherichia coli, and marine bacteria from an aquaculture area in Chile.

    Science.gov (United States)

    Aedo, Sandra; Ivanova, Larisa; Tomova, Alexandra; Cabello, Felipe C

    2014-08-01

    Marine bacteria from aquaculture areas with industrial use of quinolones have the potential to pass quinolone resistance genes to animal and human pathogens. The VPA0095 gene, related to the quinolone resistance determinant qnrA, from clinical isolates of epidemic Vibrio parahaemolyticus conferred reduced susceptibility to quinolone after cloning into Escherichia coli K-12 either when acting alone or synergistically with DNA gyrase mutations. In addition, a plasmid-mediated quinolone resistance gene from marine bacteria, aac(6')-Ib-cr, was identical to aac(6')-Ib-cr from urinary tract isolates of E. coli, suggesting a recent flow of this gene between these bacteria isolated from different environments. aac(6')-Ib-cr from E. coli also conferred reduced susceptibility to quinolone and kanamycin when cloned into E. coli K-12.

  13. Use of Probiotics in Aquaculture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diseases of cultured animal and environmental pollution are very important problems in aquaculture.The use of probiotics in aquaculture has more adva ntages than the use of antibiotics and chemicals in aquaculture. This review int roduces the use and mechanisms of the probiotics in aquaculture.

  14. Enclosure enhancement of flight performance

    KAUST Repository

    Ghommem, Mehdi

    2014-08-19

    We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust.

  15. Enclosure enhancement of flight performance

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust.

  16. 50 CFR 14.151 - Primary enclosures.

    Science.gov (United States)

    2010-10-01

    ... Wild Mammals and Birds to the United States Specifications for Sloths, Bats, and Flying Lemurs... located on the upper one-half of the primary enclosure. (b) No more than one sloth, bat, or flying lemur... together may be shipped in the same primary enclosure. (c) A primary enclosure used to transport...

  17. Aquaculture in mangrove environment

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    of prawns, bivalves and finfishes. General consensus based on the analysis of cost factor, pond management efficiency and annual production levels has indicated that the disadvantages of setting up of large-scale commercial aquaculture ventures in mangrove...

  18. BIOFILTERS IN AQUACULTURE

    Directory of Open Access Journals (Sweden)

    Ivo Šarić

    2010-07-01

    Full Text Available Recirculating aquaculture is one of the solutions to an environmentally sustainable and economically feasible aquaculture production, and can be established in either urban or rural communities. Controlled conditions enable optimal growth conditions suitable for the species in question during the whole growth process, as well as the shortening of the process itself, when compared to open uncontrolled systems. Recirculating systems are now one of the most researched fields of aquaculture, and biofiltration as the reduction of the poisonous ammonia compounds generated by digestion of proteins, is one of its most important parts. The aim of this study was to stress the importance of biofiltration, and to describe different designs of biofilters. Many biofilters are being used in commercial and research aquaculture facilities with differences in choice of working organism, design, material, price and etc. For the proper choice of biofilter it is necessary to know characteristics of each recirculating aquaculture system, because there are still no strict criteria for categorizing and applying different biofilter designs.

  19. Cold Climate Building Enclosure Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, J.; Fallahi, A.; Shukla, N.

    2013-01-01

    This project investigates the energy performance and cost effectiveness of several state-of-the-art retrofit strategies that could be used in triple-deckers and colonial houses, common house types in New England. Several emerging building enclosure technologies were integrated, including high R-value aerogel and vacuum insulations, in forms that would be energy efficient, flexible for different retrofit scenarios, durable, and potentially cost-competitive for deep energy retrofits.

  20. Optimisation of mesh enclosures for nursery rearing of juvenile sea cucumbers.

    Science.gov (United States)

    Purcell, Steven W; Agudo, Natacha S

    2013-01-01

    Mariculture of tropical sea cucumbers is promising, but the nursery rearing of juveniles is a bottleneck for farming and sea ranching. We conducted four medium-scale experiments lasting 3-6 weeks, using thousands of cultured juvenile sandfish Holothuria scabra, to optimise nursery rearing in mesh enclosures in earthen seawater ponds and to test rearing in enclosures in the sea. In one experiment, survival in fine-mesh enclosures (1 m(3); 660-µm mesh) related nonlinearly to juvenile size, revealing a threshold body length of 5-8 mm for initial transfer from hatchery tanks. Survival in enclosures within ponds in the other experiments ranged from 78-97%, and differences in growth rates among experiments were explained largely by seasonal differences in seawater temperatures in ponds. Stripped shadecloth units within fine-mesh enclosures increased feeding surfaces and improved growth rates by >15%. On the other hand, shading over the enclosures may lower growth rates. Following the rearing in fine-mesh enclosures, small juveniles (0.5 to 1 g) were grown to stocking size (3-10 g) in coarse-mesh enclosures of 1-mm mesh. Sand or mud added to coarse-mesh enclosures did not significantly improve growth compared to controls without sediment. Survival of sandfish juveniles in coarse-mesh enclosures set on the benthos within seagrass beds differed between two sheltered bays and growth was slow compared to groups within the same type of enclosures in an earthen pond. Our findings should lead to significant improvement in the cost-effectiveness of rearing sandfish juveniles to a stocking size compared to established methods and highlight the need for further research into nursery systems in the sea.

  1. Certify Sustainable Aquaculture?

    DEFF Research Database (Denmark)

    Bush, Simon; Belton, Ben; Hall, Derek;

    2013-01-01

    ) fisheries production stagnating, aquaculture may help close the forecast global deficit in fish protein by 2020 (2). This so-called “blue revolution” requires addressing a range of environmental and social problems, including water pollution, degradation of ecosystems, and violation of labor standards.......Aquaculture, the farming of aquatic organisms, provides close to 50% of the world's supply of seafood, with a value of U.S. $125 billion. It makes up 13% of the world's animal-source protein (excluding eggs and dairy) and employs an estimated 24 million people (1). With capture (i.e., wild...

  2. Biotechnological Innovations in Aquaculture

    Directory of Open Access Journals (Sweden)

    Mangesh M. Bhosale

    2016-04-01

    Full Text Available Aquaculture is gaining commendable importance to meet the required protein source for ever increasing human population. The aquaculture industry is currently facing problems on developing economically viable production systems by reducing the impact on environment. Sustainable and enhanced fish production from aquaculture may be better achieved through application of recent biotechnological innovations. Utilisation of transgenic technology has led to production of fishes with faster growth rate with disease resistance. The full advantage of this technology could not be achieved due to concern of acceptance for Genetically Modified Organisms (GMOs. The biotechnological intervention in developing plant based feed ingredient in place of fish meal which contain high phosphorus is of prime area of attention for fish feed industry. The replacement of fish meal will also reduce fish feed cost to a greater extent. Year round fish seed production of carps through various biotechnological interventions is also need of the hour. This paper discusses technical, environmental and managerial considerations regarding the use of these biotechnological tools in aquaculture along with the advantages of research application and its commercialization.

  3. Aquaculture. Teacher Edition.

    Science.gov (United States)

    Walker, Susan S.

    This color-coded guide was developed to assist teachers in helping interested students plan, build, stock, and run aquaculture facilities of varied sizes. The guide contains 15 instructional units, each of which includes some or all of the following basic components: objective sheet, suggested activities for the teacher, instructor supplements,…

  4. Confinement Aquaculture. Final Report.

    Science.gov (United States)

    Delaplaine School District, AR.

    The Delaplaine Agriculture Department Confinement Project, begun in June 1988, conducted a confinement aquaculture program by comparing the growth of channel catfish raised in cages in a pond to channel catfish raised in cages in the Black River, Arkansas. The study developed technology that would decrease costs in the domestication of fish, using…

  5. Microalgae for aquaculture

    NARCIS (Netherlands)

    Michels, M.H.A.

    2015-01-01

    In 2007, the project ‘Zeeuwse Tong’ (Zeeland Sole) was founded with support of the province of Zeeland, the Netherlands. The aim of the Zeeuwse Tong project was to establish an innovative land-based integrated multi-trophic aquaculture sector, which is producing sole, ragworms, algae, shellfish and

  6. Aquaculture Sector Review

    OpenAIRE

    International Finance Corporation

    2015-01-01

    This aquaculture sector review (with supply chain mapping) has been implemented within the framework of the International Finance Corporation (IFC) Armenia investment climate reform project implemented by the World Bank Group trade and competitiveness global practice, in partnership with Austria’s federal ministry of finance and Hungarian partnership funding and Hungary Export Import (EXIM...

  7. 33 CFR 127.709 - Protective enclosures.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Security § 127.709 Protective enclosures. The...

  8. Vertical Integration in the Taiwan Aquaculture Industry

    Directory of Open Access Journals (Sweden)

    Tzong-Ru Lee (Jiun-Shen

    2011-12-01

    Full Text Available The study aims to improve the distribution channels in the Taiwanaquaculture industry through a better vertical integration. This studyis derived from a need to improve the distribution performance ofagricultural-based industries in response to increasing food demandsin Asia and elsewhere. Based on a four-by-eight matrix derived fromboth a value chain and a service profit chain, thirty different strategiesare developed. This development is based on key success factors andstrategies for vertical integration interviewed and cited in the literatures.The findings are identified by applying the Gray Relational Analysis(GRA. For this study, the key success factors for aquaculture wholesalemarkets include the communication, integration and cohesion ofopinion within the wholesale market; government support; andmutualtrust between members of the vertical integration scheme. The suitablevertical integration strategies are an improved safety and hygiene inspectionof aquaculture products, accuracy of aquaculture product categorization,and precision in product weighing.

  9. Inverness College: Innovations in Aquaculture Training.

    Science.gov (United States)

    Regional Technology Strategies, Inc., Carrboro, NC.

    This paper describes the aquaculture program developed at Inverness College in Scotland. Inverness is located in the Scottish Highlands and serves an area roughly the size of Belgium, but with a population of only 300,000. The regional infrastructure and human capital resources in the Highlands are relatively weak due to inadequate transportation,…

  10. PROCEDURE FOR ESTIMATING PERMANENT TOTAL ENCLOSURE COSTS

    Science.gov (United States)

    The paper discusses a procedure for estimating permanent total enclosure (PTE) costs. (NOTE: Industries that use add-on control devices must adequately capture emissions before delivering them to the control device. One way to capture emissions is to use PTEs, enclosures that mee...

  11. The influence of enclosure design on diurnal activity and stereotypic behaviour in captive Malayan Sun bears (Helarctos malayanus).

    Science.gov (United States)

    Tan, H M; Ong, S M; Langat, G; Bahaman, A R; Sharma, R S K; Sumita, S

    2013-04-01

    The effect of enclosure design on diurnal activity and stereotypic behaviour was assessed in 17 adult Malayan Sun bears (Helarctos malayanus), kept either in barren indoor enclosures or relatively enriched outdoor enclosures. Locomotion was the most frequent activity observed in the indoor bears, followed by resting. In contrast, conspecifics housed outdoors spent most of the time resting. Eleven forms of stereotypic behaviours were recorded in the bears, with pacing being the most common. The frequency and repertoire of stereotypies were significantly higher in the indoor bears irrespective of enclosure size. Novel forms of locomotor (forward-reverse pacing) and oral (allo-sucking) stereotypies were recorded. Oral stereotypies were predominant in the bears housed indoors, while patrolling was confined to the outdoor bears. Enclosure complexity significantly influences activity budget and occurrence of stereotypic behaviours, highlighting the importance of appropriate enclosure design and enrichment for the welfare of captive bears.

  12. Live feeds in aquaculture

    OpenAIRE

    Dhert, Ph.; Sorgeloos, P

    1995-01-01

    Over the past two decades intensive larviculture of several fish and shellfish species has expanded into a multimillion dollar industry. Although much progress has been made in identifying the dietary requirements of the larvae of various aquaculture species, the mass culture of their early larval stages still requires the use of live feeds. Selected either through trial and error approaches or because of their convenience in mass production and use, hatcheries are relying today on three grou...

  13. PROTEOMICS in aquaculture

    DEFF Research Database (Denmark)

    Rodrigues, Pedro M.; Silva, Tomé S.; Dias, Jorge

    2012-01-01

    growth in production is still expected for decades to come. Aquaculture is, though, a very competitive market, and a global awareness regarding the use of scientific knowledge and emerging technologies to obtain a better farmed organism through a sustainable production has enhanced the importance...... nutritional, health or quality properties for functional foods and the integration of proteomics techniques in addressing this challenging issue. This article is part of a Special Issue entitled: Farm animal proteomics....

  14. Background paper on aquaculture research

    DEFF Research Database (Denmark)

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto

    80 million tonnes accounting for close to 50 % of all aquatic food destined for the global human consumption. The Swedish aquaculture production currently includes about 11,000 tonnes rainbow trout in FW and SW, 1,100 tonnes arctic char (FW), 90 tonnes eel (FW), 1,500 tonnes mussels (SW) and a few...... to include technologies and strategies to minimize the environmental impact, in particular to the Baltic Sea. Swedish aquaculture may develop to be an environmental service, which may be exported. The governmental policy on aquaculture should reflect the conclusions of the official report Det växande...... and powerful Swedish aquaculture to develop, strong and committing policy instruments should be coordinated and managed. This means that the strategy for aquaculture needs to be followed by a long term focused research policy on aquaculture and responsibility for putting it into force as well as availability...

  15. Microbial Diseases in Shrimp Aquaculture

    Digital Repository Service at National Institute of Oceanography (India)

    Karunasagar, Iddya; Karunasagar, Indrani; Umesha, R.K.

    Diseases in Shrimp Aquaculture Iddya Karunasagar, Indrani Karunasagar and R. K. Umesha Department of Fishery Microbiology, University of Agricultural Sciences, College of Fisheries, Mangalore-575 002, India Introduction Aquaculture is one of the fastest... growing food production sectors in the world (Subasinghe et al. 1998). According to FAO statistics, over 80% of fish produced by aquaculture comes from Asia, with the production valued at $ 38.855 billion (FAO, 1996). However, disease outbreaks have caused...

  16. Chemical and Sensory Quantification of Geosmin and 2-Methylisoborneol in Rainbow Trout (Oncorhynchus mykiss) from Recirculated Aquacultures in Relation to Concentrations in Basin Water

    DEFF Research Database (Denmark)

    Petersen, Mikael A.; Hyldig, Grethe; Strobel, Bjarne W.;

    2011-01-01

    Globally, aquaculture systems with water recirculation experience increasing problems with microbial taste and odor compounds (TOCs) such as geosmin and 2-methylisoborneol (MIB). This study investigated the content of geosmin and MIB in water and the flesh of 200 rainbow trouts from eight...... recirculated aquaculture systems in Denmark. TOC content in the fish flesh was measured by a dynamic headspace extraction method and was evaluated by a sensory panel. The results showed significant correlations between TOC content in water and fish and between chemical analysis and sensory perception. When...... geosmin exceeded 20 ng/L in the water, 96% of the fish had an intense muddy flavor, but below 10 ng geosmin/L, 18% of the fish (only 3% in special depuration ponds) had an intense muddy flavor. The results indicate that TOC levels...

  17. Chemical and sensory quantification of geosmin and 2-methylisoborneol in rainbow trout (Oncorhynchus mykiss) from recirculated aquacultures in relation to concentrations in basin water.

    Science.gov (United States)

    Petersen, Mikael A; Hyldig, Grethe; Strobel, Bjarne W; Henriksen, Niels H; Jørgensen, Niels O G

    2011-12-14

    Globally, aquaculture systems with water recirculation experience increasing problems with microbial taste and odor compounds (TOCs) such as geosmin and 2-methylisoborneol (MIB). This study investigated the content of geosmin and MIB in water and the flesh of 200 rainbow trouts from eight recirculated aquaculture systems in Denmark. TOC content in the fish flesh was measured by a dynamic headspace extraction method and was evaluated by a sensory panel. The results showed significant correlations between TOC content in water and fish and between chemical analysis and sensory perception. When geosmin exceeded 20 ng/L in the water, 96% of the fish had an intense muddy flavor, but below 10 ng geosmin/L, 18% of the fish (only 3% in special depuration ponds) had an intense muddy flavor. The results indicate that TOC levels <10 ng/L will ensure that a negligible portion of the fish obtains an unpalatable taste and flavor due to TOCs.

  18. PROTEOMICS in aquaculture: applications and trends.

    Science.gov (United States)

    Rodrigues, Pedro M; Silva, Tomé S; Dias, Jorge; Jessen, Flemming

    2012-07-19

    Over the last forty years global aquaculture presented a growth rate of 6.9% per annum with an amazing production of 52.5 million tonnes in 2008, and a contribution of 43% of aquatic animal food for human consumption. In order to meet the world's health requirements of fish protein, a continuous growth in production is still expected for decades to come. Aquaculture is, though, a very competitive market, and a global awareness regarding the use of scientific knowledge and emerging technologies to obtain a better farmed organism through a sustainable production has enhanced the importance of proteomics in seafood biology research. Proteomics, as a powerful comparative tool, has therefore been increasingly used over the last decade to address different questions in aquaculture, regarding welfare, nutrition, health, quality, and safety. In this paper we will give an overview of these biological questions and the role of proteomics in their investigation, outlining the advantages, disadvantages and future challenges. A brief description of the proteomics technical approaches will be presented. Special focus will be on the latest trends related to the aquaculture production of fish with defined nutritional, health or quality properties for functional foods and the integration of proteomics techniques in addressing this challenging issue.

  19. Towards energy efficient high-rise residential building enclosures: insight from energy bills and enclosure rehabilitations

    Energy Technology Data Exchange (ETDEWEB)

    Finch, Graham; Knowles, Warren; Ricketts, Lorne [RDH Building Engineering Ltd., Vancouver, (Canada)

    2010-07-01

    The building industry is looking to reduce energy consumption and the environmental impact of all building types. This paper investigated the relationship between current building practices and space heating in high-rise multi-unit residential buildings (MURBs). A summary of some of the key findings from a larger study with a focus on issues related to building enclosure conductive thermal losses was presented. This work involved the assessment of energy consumption data and, more specifically, of the space heating characteristics for mid and high-rise MURBs in the Lower Mainland of Vancouver which were selected as representative of typical MURB housing stock and included buildings with architectural forms common to other mid and high-rise residential buildings across North America. The effective R-value for all building enclosure assemblies for each building was calculated and compared with energy bills. The R-values were compared to ASHRAE 90.1. It was found that the overall effective R-values ranges were between R-2 and R-5 ft2 hr F/Btu.

  20. Aquaculture. Second Edition. Teacher Edition.

    Science.gov (United States)

    Walker, Susan S.; Crummett, Dan

    This teacher and student guide for aquaculture contains 15 units of instruction that cover the following topics: (1) introduction to aquaculture; (2) the aquatic environment; (3) fundamental fish biology; (4) marketing; (5) site selection; (6) facility design and layout; (7) water quality management; (8) fish health management; (9) commercial…

  1. Interaction Between Flow Elements in Large Enclosures

    DEFF Research Database (Denmark)

    Heiselberg, Per

    In this paper experiments in a scale model are used as a first attempt to investigate how different flow elements such as supply air jets, thermal plumes and free convection flows interact with each other in a large enclosure, if the path of each individual flow element changes and if this influe......In this paper experiments in a scale model are used as a first attempt to investigate how different flow elements such as supply air jets, thermal plumes and free convection flows interact with each other in a large enclosure, if the path of each individual flow element changes...... and if this influences the overall air flow pattern in the enclosure. The main emphasis has been put on the pathways of chilled free air jets and whether the convective flows from both distributed and concentrated heat sources affect the pathway of the jet and the air flow pattern in the enclosure as a function...

  2. Practical considerations for permanent total enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Worrall, M. [Amcec Adsorption Systems, Schaumburg, IL (United States)

    1997-12-31

    This paper considers some of the practical consideration of Permanent Total Enclosures (PTEs) for gravure printing facilities. In particular the dispersion of fugitive losses from the presses by thermal air currents generated by heat from the press dryers.

  3. Disease and health management in Asian aquaculture.

    Science.gov (United States)

    Bondad-Reantaso, Melba G; Subasinghe, Rohana P; Arthur, J Richard; Ogawa, Kazuo; Chinabut, Supranee; Adlard, Robert; Tan, Zilong; Shariff, Mohamed

    2005-09-30

    Asia contributes more than 90% to the world's aquaculture production. Like other farming systems, aquaculture is plagued with disease problems resulting from its intensification and commercialization. This paper describes the various factors, providing specific examples, which have contributed to the current disease problems faced by what is now the fastest growing food-producing sector globally. These include increased globalization of trade and markets; the intensification of fish-farming practices through the movement of broodstock, postlarvae, fry and fingerlings; the introduction of new species for aquaculture development; the expansion of the ornamental fish trade; the enhancement of marine and coastal areas through the stocking of aquatic animals raised in hatcheries; the unanticipated interactions between cultured and wild populations of aquatic animals; poor or lack of effective biosecurity measures; slow awareness on emerging diseases; the misunderstanding and misuse of specific pathogen free (SPF) stocks; climate change; other human-mediated movements of aquaculture commodities. Data on the socio-economic impacts of aquatic animal diseases are also presented, including estimates of losses in production, direct and indirect income and employment, market access or share of investment, and consumer confidence; food availability; industry failures. Examples of costs of investment in aquatic animal health-related activities, including national strategies, research, surveillance, control and other health management programmes are also provided. Finally, the strategies currently being implemented in the Asian region to deal with transboundary diseases affecting the aquaculture sector are highlighted. These include compliance with international codes, and development and implementation of regional guidelines and national aquatic animal health strategies; new diagnostic and therapeutic techniques and new information technology; new biosecurity measures including

  4. Enclosure for handling high activity materials

    Energy Technology Data Exchange (ETDEWEB)

    Jimeno de Osso, F.

    1977-07-01

    One of the most important problems that are met at the laboratories producing and handling radioisotopes is that of designing, building and operating enclosures suitable for the safe handling of active substances. With this purpose in mind, an enclosure has been designed and built for handling moderately high activities under a shielding made of 150 mm thick lead. In this report a description is given of those aspects that may be of interest to people working in this field. (Author)

  5. Modeling of TAN in recirculating aquaculture systems by AQUASIM

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2011-01-01

    Modeling of total ammonium nitrogen (TAN) in recirculating aquaculture systems (RAS) contribute to identifying and quantifying the most important processes and their relative contribution to removal of TAN. AQUASIM is a flexible modular simulation system for water quality in natural and technical...... systems developed by EAWAG (Reichert, 1994). AQUASIM allows simulating complex biological, chemical and physical processes in standardized hydraulic systems. We used AQUASIM to model the steady state TAN concentrations in 12 experimental recirculating aquaculture systems (RAS) operated by DTU AQUA...

  6. Relative Abundance of Nitrotoga spp. in a Biofilter of a Cold-Freshwater Aquaculture Plant Appears To Be Stimulated by Slightly Acidic pH

    Science.gov (United States)

    Hüpeden, Jennifer; Wegen, Simone; Off, Sandra; Lücker, Sebastian; Bedarf, Yvonne; Daims, Holger; Kühn, Carsten

    2016-01-01

    The functioning of recirculation aquaculture systems (RAS) is essential to maintain water quality for fish health, and one crucial process here is nitrification. The investigated RAS was connected to a rainbow trout production system and operated at an average temperature of 13°C and pH 6.8. Community analyses of the nitrifying biofilm revealed a coexistence of Nitrospira and Nitrotoga, and it is hypothesized that a slightly acidic pH in combination with lower temperatures favors the growth of the latter. Modification of the standard cultivation approach toward lower pH values of 5.7 to 6.0 resulted in the successful enrichment (99% purity) of Nitrotoga sp. strain HW29, which had a 16S rRNA sequence similarity of 99.0% to Nitrotoga arctica. Reference cultures of Nitrospira defluvii and the novel Nitrotoga sp. HW29 were used to confirm differentiation of these nitrite oxidizers in distinct ecological niches. Nitrotoga sp. HW29 revealed pH and temperature optima of 6.8 and 22°C, respectively, whereas Nitrospira defluvii displayed the highest nitrite oxidation rate at pH 7.3 and 32°C. We report here the occurrence of Nitrotoga as one of the main nitrite-oxidizing bacteria in freshwater aquaculture systems and indicate that a slightly acidic pH, in addition to temperatures below 20°C, can be applied as a selective isolation criterion for this microorganism. PMID:26746710

  7. Meagre (Argyrosomus regius Asso, 1801 aquaculture in Croatia

    Directory of Open Access Journals (Sweden)

    Kružić Nikolina

    2016-03-01

    Full Text Available The objective of this review is to present current status of meagre aquaculture in Croatia. Meagre Argyrosomus regius (Asso, 1801 is a fast growing migratory fish species which used to be widespread along the coast of the Adriatic Sea. Today, it is very rare in fisheries catches and is considered highly endangered. Recently, meagre has become an increasingly important species in the Mediterranean aquaculture. In Croatia, meagre is a relatively new cultured species whose farming started after the year 2000. Since the European Commission identified species diversification as a top priority in the framework of the 2020 strategies for Aquaculture, and with recent studies revealing that meagre adapt easily to captivity and maintain a rapid growth rate, this species became an interesting candidate for Croatian as well as Mediterranean aquaculture.

  8. DNA vaccines for aquacultured fish

    DEFF Research Database (Denmark)

    Lorenzen, Niels; LaPatra, S.E.

    2005-01-01

    of licensing and public acceptance of the technology. The potential benefits of DNA vaccines for farmed fish include improved animal welfare, reduced environmental impacts of aquaculture activities, increased food quality and quantity, and more sustainable production. Testing under commercial production...

  9. Making social sense of aquaculture transitions

    Directory of Open Access Journals (Sweden)

    Simon R. Bush

    2014-09-01

    Full Text Available Resilience deals explicitly with change and provides a middle ground between the social and the environmental sciences. However, a growing critique by social scientists questions the ability of resilience thinking to adequately examine the social dimensions of change. The question that emerges is how social scientists should engage with resilience. We addressed this question by comparing resilience with agrarian change and transitions theory, through the backdrop of the fastest growing global food sector, aquaculture. Our analysis showed that each theoretical perspective provides fundamentally different insights into social and environmental transition inherent in the aquaculture sector. Although resilience thinking is best suited to assessing the ecological aspects of production, its systems ontology limits the inclusion of dynamic social relations or innovation. In contrast, agrarian transition enables a more meaningful understanding of how social relations are reconfigured as agrarian society shifts toward more capitalist modes of production, and transitions theory provides insights into social process of innovation. Given the epistemological differences between these theoretical approaches, we argue against attempts that reify systemic thinking by naturalizing social theories and concepts into resilience thinking. Instead, we argue that social theories such as agrarian change and transition theory should be seen as complimentary and that integration should focus on bridging results and insights. Doing so enables a more robust assessment of the social aspects of social-ecological transitions in the aquaculture sector and beyond.

  10. The use of yeast as single-cell protein in aquacultural diets

    OpenAIRE

    Coutteau, P. (Peter); Lavens, P.

    1989-01-01

    Aquaculture is becoming more and more an industrial practice. However, feed cost, which may mount up to around 30% of the total operating costs still appears to be one of the major constraints for further expansion of aquaculture. Due to the relatively inexpensive mass-production of yeasts, serious efforts have been made to evaluate the incorporation of these Single-Cell Proteins in aquaculture diets. The aim of this communication is to review the most important results obtained with yeast di...

  11. BIOTECHNOLOGY OF THE FISH AQUACULTURE

    OpenAIRE

    L. P. Buchatsky

    2013-01-01

    The latest progress in biotechnology on fish aquaculture and different modern methods of investigations for increasing of fish productivity in aquaculture are analyzed. Except for the applied aspect, the use of modern biotechnological methods of investigations opens new possibilities for fundamental researches of sex-determining mechanisms, polyploidy, distant hybridization, and developmental biology of bony fishes. Review contains examples of utilizing modern biotechnology methods to obtain ...

  12. Knowledge Enclosures, Forced Specializations and Investment Crisis

    Directory of Open Access Journals (Sweden)

    Filippo Belloc

    2012-12-01

    Full Text Available Like land before the industrial revolution, in the present global economy much knowledge is being enclosed in private hands. In this paper we argue that these enclosures have become a major factor in specialization among firms and among countries: both are forced to specialize in the fields that are not restricted by the enclosures of the others. We use data on 26 OECD countries over the 1978-2006 period. We estimate the effect of patents endowments of countries on their investment specialization across sectors and show that knowledge enclosures involve self-reinforcing innovation patterns. Moreover, we perform a structural change analysis and find that the TRIPs agreement has significantly strengthened the relationship between countries' patents specialization and investment specialization. We conclude by suggesting that stronger international patent protection may restrict global investment opportunities, and this may be one of the factors contributing to the present crisis.

  13. 30 CFR 57.12068 - Locking transformer enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be...

  14. 30 CFR 56.12068 - Locking transformer enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked...

  15. Cask Processing Enclosure Specification/Operation - 12231

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Ronald [Transuranic Waste Processing Center, Lenoir City TN, 37771 (United States)

    2012-07-01

    Following an evaluation of throughput rates in the Hot Cell at the Transuranic Waste Processing Center and considering the variability in the waste with respect to actual dose rates a new approach to processing transuranic waste was necessary. Compounding the issue was the remote equipment poor reliability and high down-time. After considering all the factors, the evaluation resulted in the design and construction of a new waste processing area for handling the concrete casks that predominately contain contact handled transuranic (TRU) waste. The area is called the Cask Processing Enclosure and essentially the Cask Processing Enclosure mimics the projects current process techniques used for processing Contact Handled -TRU waste in the existing Box Breakdown Area and Glovebox. The Cask Processing Enclosure approach was developed based on a review of the RH processing throughput rates in the Hot Cell. As the process was reviewed consideration was given to the variability in the waste with respect to actual dose rates and the lack of equipment reliability and high wear in the Hot Cell. Based on that review, a new contact handled processing area for handling the concrete casks is being constructed and startup is expected shortly following WM2012. The Cask Processing Enclosure essentially mimics the projects current process techniques used for processing Contact Handled waste in the existing Box Breakdown Area and Glovebox and the design takes into consideration six years of operational experience. (authors)

  16. 9 CFR 3.53 - Primary enclosures.

    Science.gov (United States)

    2010-01-01

    ... used at research facilities when approved by the Institutional Animal Care and Use Committee, and by... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary enclosures. 3.53 Section 3.53 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  17. 9 CFR 3.6 - Primary enclosures.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary enclosures. 3.6 Section 3.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Dogs...

  18. 9 CFR 3.28 - Primary enclosures.

    Science.gov (United States)

    2010-01-01

    ... Animal Care and Use Committee, and by dealers and exhibitors when approved by the Administrator. Animal... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary enclosures. 3.28 Section 3.28 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  19. 9 CFR 3.80 - Primary enclosures.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary enclosures. 3.80 Section 3.80 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of...

  20. Aquaculture practices and the coastal marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Sreepada, R.A.

    Aquaculture has the potential for causing environmental harm as well as for improving livelihood and nutrition. Aquaculture development, therefore requires to be seen in the wider context of aquatic resource use, land use development and its...

  1. Mediterranean Aquaculture: Marine Fish Farming Development

    OpenAIRE

    Basurco, B

    2001-01-01

    in many parts of the world, aquaculture production in the Mediterranean has been expanding rapidly over recent years. Total aquaculture production in the region reached 1,266,959 t in 1999, which represents approximately 6% of the world aquaculture production (3% in 1995). Although Mediterranean aquaculture still focuses more on mollusc production (53.9%), the share of fish production is progressing constantly (46% in 1999, and 35% in 1995), parallel to global trends of world a...

  2. A comprehensive survey on selective breeding programs and seed market in the European aquaculture fish industry

    NARCIS (Netherlands)

    Chavanne, Hervé; Janssen, K.P.E.; Hofherr, Johann; Contini, Franca; Haffray, P.; Komen, J.; Nielsen, E.E.; Bargelloni, L.

    2016-01-01

    The use of selective breeding is still relatively limited in aquaculture species. Information on such activities is sparse, hindering an overall evaluation of their success. Here, we report on the results of an online survey of the major aqua-culture breeding companies operating in Europe. Six main

  3. Compartmentalisation in aquaculture production systems.

    Science.gov (United States)

    Zepeda, C; Jones, J B; Zagmutt, F J

    2008-04-01

    Compartmentalisation is a new tool for disease management within a country. In aquaculture, the successful application of compartmentalisation is largely dependent on the system of production and the epidemiology of the disease(s) for which the compartment is being defined. Therefore, compartmentalisation may not be universally applicable across all systems and diseases. The paper examines the implementation of the concept, providing examples of specific industries, and discusses the application of hazard analysis and critical control points (HACCP) to the biosecurity of the system. The role of compartmentalisation in the management of aquaculture disease emergencies is also discussed.

  4. Applications of probiotic in aquaculture

    Directory of Open Access Journals (Sweden)

    Seval Bahadır Koca

    2011-10-01

    Full Text Available Ecological impacts including emergence of a large variety of pathogens and bacterial resistance is caused in increase of productivity in aquaculture. This negatively effects are seen as a results of made applications in production cycles (such as randomly use kemoteropatik. Using probi¬otic in aquaculture is a new approach to reduce these negatively effects. In this study is submi¬ted, definition of the concept probiotic, effect mechanisms of probiotics, colonization to host, selection of probiotics, use probiotic in fish, crustacean, the mollusk and the live feed.

  5. Increased competition for aquaculture from fisheries

    DEFF Research Database (Denmark)

    Jensen, Frank; Nielsen, Max; Nielsen, Rasmus

    2014-01-01

    ; and supplies from aquaculture have grown continuously. In this paper, the impact of improved fisheries management on aquaculture growth is studied assuming perfect substitution between farmed and wild fish. We find that improved fisheries management, ceteris paribus, reduces the growth potential of global...... aquaculture in markets where wild fisheries constitute a large share of total supply....

  6. Aquaculture Thesaurus: Descriptors Used in the National Aquaculture Information System.

    Science.gov (United States)

    Lanier, James A.; And Others

    This document provides a listing of descriptors used in the National Aquaculture Information System (NAIS), a computer information storage and retrieval system on marine, brackish, and freshwater organisms. Included are an explanation of how to use the document, subject index terms, and a brief bibliography of the literature used in developing the…

  7. DNA vaccines for aquacultured fish.

    Science.gov (United States)

    Lorenzen, N; LaPatra, S E

    2005-04-01

    Deoxyribonucleic acid (DNA) vaccination is based on the administration of the gene encoding the vaccine antigen, rather than the antigen itself. Subsequent expression of the antigen by cells in the vaccinated hosts triggers the host immune system. Among the many experimental DNA vaccines tested in various animal species as well as in humans, the vaccines against rhabdovirus diseases in fish have given some of the most promising results. A single intramuscular (IM) injection of microgram amounts of DNA induces rapid and long-lasting protection in farmed salmonids against economically important viruses such as infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). DNA vaccines against other types of fish pathogens, however, have so far had limited success. The most efficient delivery route at present is IM injection, and suitable delivery strategies for mass vaccination of small fish have yet to be developed. In terms of safety, no adverse effects in the vaccinated fish have been observed to date. As DNA vaccination is a relatively new technology, various theoretical and long-term safety issues related to the environment and the consumer remain to be fully addressed, although inherently the risks should not be any greater than with the commercial fish vaccines that are currently used. Present classification systems lack clarity in distinguishing DNA-vaccinated animals from genetically modified organisms (GMOs), which could raise issues in terms of licensing and public acceptance of the technology. The potential benefits of DNA vaccines for farmed fish include improved animal welfare, reduced environmental impacts of aquaculture activities, increased food quality and quantity, and more sustainable production. Testing under commercial production conditions has recently been initiated in Canada and Denmark.

  8. Cumulative effects, creeping enclosure, and the marine commons of New Jersey

    Directory of Open Access Journals (Sweden)

    Grant Murray

    2010-02-01

    Full Text Available In response to declining fish stocks and increased societal concern, the marine ‘commons’ of New Jersey is no longer freely available to commercial and recreational fisheries. We discuss the concept of ‘creeping’ enclosure in relation to New Jersey’s marine fisheries and suggest that reduced access can be a cumulative process and function of multiple events and processes and need not be the result of a single regulatory moment. We begin with a short review of the ‘expected’ effects of enclosure, including loss of flexibility, erosion of community, proletarianization of fishermen, and corporatization of the fishery. We then present some findings of our research and discuss how the signs of enclosure are visible in fisheries that do not feature explicitly privatized property or access rights. We rely on an oral history approach and the rich detail that emerges from attention to the lived experiences of fish harvesters to provide a framework for understanding the range of cumulative effects that have resulted from this process of creeping enclosure. We conclude with a discussion of how the gradual process of enclosure has affected the flows of information between the bio-physical environment and fish harvesters, managers and scientists by reducing both participation in fisheries and the accumulation of knowledge itself.

  9. Helminth parasites of finfish commercial aquaculture in Latin America.

    Science.gov (United States)

    Soler-Jiménez, L C; Paredes-Trujillo, A I; Vidal-Martínez, V M

    2017-03-01

    Latin America has tripled production by aquaculture up to 78 million tonnes in the past 20 years. However, one of the problems that aquaculture is facing is the presence of helminth parasites and the diseases caused by them in the region. In this review we have collected all the available information on helminths affecting commercial aquaculture in Latin America and the Caribbean (LAC), emphasizing those causing serious economic losses. Monogeneans are by far the most common and aggressive parasites affecting farmed fish in LAC. They have been recognized as serious pathogens in intensive fish culture because they reach high levels of infection rapidly, and can infect other phylogenetically related fish species. The next most important group comprises the larval stages of digeneans (metacercariae) such as Diplostomum sp. and Centrocestus formosanus, which cause serious damage to farmed fish. Since LAC aquaculture has been based mainly on exotic species (tilapia, salmon, trout and carp), most of their parasites have been brought into the region together with the fish for aquaculture. Recently, one of us (A.I.P.-T.) has suggested that monogeneans, which have generally been considered to be harmless, can produce serious effects on the growth of cultured Nile tilapia. Therefore, the introduction of fish together with their 'harmless' parasites into new sites, regions or countries in LAC should be considered a breakdown of biosecurity in those countries involved. Therefore, the application of quarantine procedures and preventive therapeutic treatments should be considered before allowing these introductions into a country.

  10. CFD simulation and statistical analysis of moisture transfer into an electronic enclosure

    DEFF Research Database (Denmark)

    Shojaee Nasirabadi, Parizad; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

    2016-01-01

    Condensation and moisture related problems are the cause of failures in many cases and consequently serious concerns for reliability in electronics industry. Thus, it is important to control the moisture content and the relative humidity inside electronic enclosures. In this work, a computational...

  11. Enhancing fish performance in Aquaculture

    Science.gov (United States)

    Aquaculture currently is the fastest growing agricultural industry and must continue to grow to meet the world’s increasing demand for seafood. Continued growth will depend upon advances in fish genetics and nutrition, and improvements in culture system design and management. The number and complexi...

  12. QTL mapping designs for aquaculture.

    NARCIS (Netherlands)

    Massault, C.; Bovenhuis, H.; Haley, C.S.; Koning, de D.J.

    2008-01-01

    Rapid development of genomics technology is providing new opportunities for genetic studies, including QTL mapping, in many aquaculture species. This paper investigates the strengths and limitations of QTL mapping designs for fish and shellfish under three different controlled breeding schemes. For

  13. Concrete enclosure to shield a neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Villagrana M, L. E.; Rivera P, E.; De Leon M, H. A.; Soto B, T. G.; Hernandez D, V. M.; Vega C, H. R., E-mail: emmanuelvillagrana@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Apdo. Postal 336, 98000 Zacatecas (Mexico)

    2012-10-15

    In the aim to design a shielding for a {sup 239}PuBe isotopic neutron source several Monte Carlo calculations were carried out using MCNP5 code. First, a point-like source was modeled in vacuum and the neutron spectrum and the ambient dose equivalent were calculated at several distances ranging from 5 up to 150 cm, these calculations were repeated including air, and a 1 x 1 x 1 m{sup 3} enclosure that was shielded with 5, 15, 20, 25, 30, 50 and 80 cm-thick Portland type concrete walls. At all the points located inside the enclosure neutron spectra from 10{sup -8} up 0.5 MeV were the same regardless the distance from the source showing the room-return effect, for energies larger than 0.5 MeV neutron spectra are diminished as the distance increases. Outside the enclosure it was noticed that neutron spectra becomes -softer- as the concrete thickness increases due to reduction of mean neutron energy. With the ambient dose values the attenuation curve in terms of concrete thickness was calculated. (Author)

  14. LSST summit enclosure-facility design optimization using aero-thermal modeling

    Science.gov (United States)

    Sebag, J.; Vogiatzis, K.; Barr, J.; Neill, D.

    2012-09-01

    This paper describes Computational Fluid Dynamic (CFD) analyses combined with thermal analyses for modeling the effects of passive ventilation, enclosure-building configuration and topography on the optical performance of the Large Synoptic Survey Telescope (LSST). The primary purpose of the analyses was to evaluate the seeing contribution of the major enclosure-facility elements and to select the features to be adopted in the baseline design from among various configurations being explored by the LSST project and the contracted architectural design team. In addition, one of several simulations for different telescope orientations is presented including various wind-telescope relative azimuth angles. Using a post-processing analysis, the effects of turbulence and thermal variations within the airflow around the buildings and inside the telescope-enclosure configuration were determined, and the optical performance due to the thermal seeing along the optical path was calculated.

  15. On Identical Problems of Natural Convection in Enclosures and APplications of the Identity Character

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    In this paper,a concept of “identical problems”of natural convection in enclosures is presented.A pair of problems of natural conyection in enclosures is said to be identical if they look different in appearance but with appropriate selection of coordinates and appropriate definition of dimensionless variables for each problem;they will have identical geometric configurations and identical dimensionless governing equations and related boundary conditions,The identical characteristics of a pair of problems of natural convection in enclosures with an interanl isolated island are demonstrated via dimensionless mathematical formulation and flow visualization results.Numericasl computations are performed and the predicted streamlines agree with the flow visualization results.A number of other possible pairs of identical problems are also presented.Applications of the identical character are provided and assumptions under which the identical problems may exist are discussed.

  16. In-situ localized carbon nanotube growth inside partially sealed enclosures

    Directory of Open Access Journals (Sweden)

    Y. van de Burgt

    2013-09-01

    Full Text Available Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition technique. The process is compatible with a variety of micro-fabrication processes and bypasses the need for post-process packaging. Our experiments raise interesting observations related to the gas diffusion dynamics in micro-scale and sub-micron enclosures.

  17. Ditched enclosures in Southern Portugal: an Archaeoastronomical view

    Science.gov (United States)

    Mejuto, A J.; Valera, A. Carlos; Castaño, J. Gómez; Rodríguez-Caderot, G.; Becker, Helmut

    2015-05-01

    Since the very first ages, human beings have attempted to understand and manage their environment in order to survive. This is the case regarding wildlife, weather cycles and gathering periods. This is also reflected in the areas surrounding sites where individuals live; they changed the landscape with different aims. This type of archaeology has risen very recently - in the last few years - and is usually called Landscape Archaeology. Traditional landscape archaeology has dealt with earth and location related studies; the relationship of ancient peoples with the sky has been disregarded. The archaeoastronomical studies have mitigated this fact. Archaeoastronomy has revealed an important number of archaeological sites; many of them reveal a clear intention of astronomically designed buildings or structures. This implies a planned detailed design and obviously a deep understanding of astronomical knowledge. As examples of these sites a number of megalithic ditched enclosures sited in Portugal will be shown which were studied inside the project "Ditched enclosures plants and Neolithic cosmologies: A landscape, archaeoastronomical and geophysical perspective". The ideological and astronomical aspects inside the architecture of these types of sites will be explained. In this paper we present a new methodology applied in the archaeoastronomical calculations for southern Portugal sites. It includes GIS techniques and the development of an archaeoastronomical layer that can be used to display the computations over cartographic information from the archaeological sites. A Spatial Data Infrastructure is also created in order to expose the results.

  18. 76 FR 9210 - Draft DOC National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ... DOC National Aquaculture Policy AGENCY: Commerce. ACTION: Notice of availability of draft aquaculture... draft national aquaculture policy that supports sustainable aquaculture in the United States. The intent of the policy is to guide DOC's actions and decisions on aquaculture and to provide a...

  19. Science, the Environment and Aquaculture

    Institute of Scientific and Technical Information of China (English)

    Liu Jian

    2002-01-01

    This paper first analyzes the problems of natural resources, the environment and agriculture in China. Secondly, it discusses the challenge of sustaining a healthy aquaculture. Thirdly, the role of science and technology in environmental management is described in detail, explaining the interaction between research and implication for govemment policymaking and local authority implementation. Finally, the institutes of the Chinese Academy of Sciences (CAS) concerned with studies of aquatic ecosystem management are introduced as examples.

  20. Use of Probiotics in Aquaculture

    Science.gov (United States)

    Martínez Cruz, Patricia; Ibáñez, Ana L.; Monroy Hermosillo, Oscar A.; Ramírez Saad, Hugo C.

    2012-01-01

    The growth of aquaculture as an industry has accelerated over the past decades; this has resulted in environmental damages and low productivity of various crops. The need for increased disease resistance, growth of aquatic organisms, and feed efficiency has brought about the use of probiotics in aquaculture practices. The first application of probiotics occurred in 1986, to test their ability to increase growth of hydrobionts (organisms that live in water). Later, probiotics were used to improve water quality and control of bacterial infections. Nowadays, there is documented evidence that probiotics can improve the digestibility of nutrients, increase tolerance to stress, and encourage reproduction. Currently, there are commercial probiotic products prepared from various bacterial species such as Bacillus sp., Lactobacillus sp., Enterococcus sp., Carnobacterium sp., and the yeast Saccharomyces cerevisiae among others, and their use is regulated by careful management recommendations. The present paper shows the current knowledge of the use of probiotics in aquaculture, its antecedents, and safety measures to be carried out and discusses the prospects for study in this field. PMID:23762761

  1. Optimal External-Memory Planar Point Enclosure

    DEFF Research Database (Denmark)

    Arge, Lars; Samoladas, Vasilis; Yi, Ke

    2007-01-01

    In this paper we study the external memory planar point enclosure problem: Given N axis-parallel rectangles in the plane, construct a data structure on disk (an index) such that all K rectangles containing a query point can be reported I/O-efficiently. This problem has important applications in e...... term O(K/B) is desired. To show this we prove a general lower bound on the tradeoff between the size of the data structure and its query cost. We also develop a family of structures with matching space and query bounds....

  2. 水产养殖对水生生态系统的影响%The Effect of Aquaculture on Aquatic Ecology

    Institute of Scientific and Technical Information of China (English)

    胡海彦; 狄瑜; 宋迁红; 邴旭文

    2011-01-01

    China was the largest aquaculture producer in the world with many cultured species, accounting for almost 70% of the world aquaculture production. However, some problems about ecology and environment were gradually emerging. The effect of enclosure aquaculture, cage aquaculture, pond aquaculture and the invasion of foreign species on aquatic ecology was discussed and some suggestions about the developmental aim of aquaculture were put forward.%我国是水产养殖大国,养殖品种众多,养殖产量占世界水产养殖总量的70%左右.但在现有的养殖环境下,一些生态环境问题也逐渐显现出来.围绕围网养殖、网箱养殖、池塘养殖、外来物种入侵等4个方面阐述了水产养殖对水生生态系统的影响以及对我国水产养殖将来的发展方向提出了几点看法.

  3. Effect of aquaculture on world fish supplies.

    Science.gov (United States)

    Naylor, R L; Goldburg, R J; Primavera, J H; Kautsky, N; Beveridge, M C; Clay, J; Folke, C; Lubchenco, J; Mooney, H; Troell, M

    2000-06-29

    Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.

  4. Optimization of electronic enclosure design for thermal and moisture management using calibrated models of progressive complexity

    DEFF Research Database (Denmark)

    Mohanty, Sankhya; Staliulionis, Zygimantas; Shojaee Nasirabadi, Parizad

    2016-01-01

    The thermal and moisture management of electronic enclosures are fields of high interest in recent years. It is now generally accepted that the protection of electronic devices is dependent on avoiding critical levels of relative humidity (typically 60–90%) during operations. Leveraging the devel......The thermal and moisture management of electronic enclosures are fields of high interest in recent years. It is now generally accepted that the protection of electronic devices is dependent on avoiding critical levels of relative humidity (typically 60–90%) during operations. Leveraging...... the development of rigorous calibrated CFD models as well as simple predictive numerical tools, the current paper tackles the optimization of critical features of a typical two-chamber electronic enclosure. The progressive optimization strategy begins the design parameter selection by initially using simpler...... equivalent RC-circuit models for concentration of water vapor and temperature in the electronic enclosure. After reducing the potential parameter-value space for the critical features using the RC-approach, the optimization strategy uses simpler 2D CFD models of temperature and moisture transport to further...

  5. Effects of seawater ozonation on biofilm development in aquaculture tanks.

    Science.gov (United States)

    Wietz, Matthias; Hall, Michael R; Høj, Lone

    2009-07-01

    Microbial biofilms developing in aquaculture tanks represent a reservoir for opportunistic bacterial pathogens, and procedures to control formation and bacterial composition of biofilms are important for the development of commercially viable aquaculture industries. This study investigated the effects of seawater ozonation on biofilm development on microscope glass slides placed in small-scale aquaculture tanks containing the live feed organism Artemia. Fluorescence in situ hybridization (FISH) demonstrated that ozonation accelerated the biofilm formation cycle, while it delayed the establishment of filamentous bacteria. Gammaproteobacteria and Alphaproteobacteria were the most abundant bacterial groups in the biofilm for both water types, but ozonation influenced their dynamics. With ozonation, the bacterial community structure was relatively stable and dominated by Gammaproteobacteria throughout the experiment (21-66% of total bacteria). Without ozonation, the community showed larger fluctuations, and Alphaproteobacteria emerged as dominant after 18 days (up to 54% of total bacteria). Ozonation of seawater also affected the dynamics of less abundant populations in the biofilm such as Betaproteobacteria, Planctomycetales and the Cytophaga/Flavobacterium branch of phylum Bacteroidetes. The abundance of Thiothrix, a bacterial genus capable of filamentous growth and fouling of larvae, increased with time for both water types, while no temporal trend could be detected for the genus Vibrio. Denaturing gradient gel electrophoresis (DGGE) demonstrated temporal changes in the dominant bacterial populations for both water types. Sequencing of DGGE bands confirmed the FISH data, and sequences were related to bacterial groups commonly found in biofilms of aquaculture systems. Several populations were closely related to organisms involved in sulfur cycling. Improved Artemia survival rates in tanks receiving ozonated water suggested a positive effect of ozonation on animal

  6. Free convective condensation in a vertical enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Fox, R.J.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States); Corradini, M.L.; Pernsteiner, A.P. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    Free convective condensation in a vertical enclosure was studied numerically and the results were compared with experiments. In both the numerical and experimental investigations, mist formation was observed to occur near the cooling wall, with significant droplet concentrations in the bulk. Large recirculation cells near the end of the condensing section were generated as the heavy noncondensing gas collecting near the cooling wall was accelerated downward. Near the top of the enclosure the recirculation cells became weaker and smaller than those below, ultimately disappearing near the top of the condenser. In the experiment the mist density was seen to be highest near the wall and at the bottom of the condensing section, whereas the numerical model predicted a much more uniform distribution. The model used to describe the formation of mist was based on a Modified Critical Saturation Model (MCSM), which allows mist to be generated once the vapor pressure exceeds a critical value. Equilibrium, nonequilibrium, and MCSM calculations were preformed, showing the experimental results to lie somewhere in between the equilibrium and nonequilibrium predictions of the numerical model. A single adjustable constant (indicating the degree to which equilibrium is achieved) is used in the model in order to match the experimental results.

  7. Enclosures Abound: Black Cultural Autonomy, Prison Regime and Public Education

    Science.gov (United States)

    Schnyder, Damien

    2010-01-01

    Since slavery, attempted enclosures upon Black spaces of cultural production and autonomy (i.e. music, language, art) have manifested in various forms. In the context of the post-industrial terrain of urban southern California, the formation of the prison is the dominant model of forced enclosure in the lives of Black people. Moving beyond the…

  8. Numerical Simulation of Transient Moisture Transfer into an Electronic Enclosure

    DEFF Research Database (Denmark)

    Shojaee Nasirabadi, Parizad; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

    2016-01-01

    inside the enclosures to be able to protect the electronic systems.In this work, moisture transfer into a typical electronic enclosure is numerically studied using CFD. In order to reduce theCPU-time and make a way for subsequent factorial design analysis, a simplifying modification is applied in which...

  9. 30 CFR 56.12026 - Grounding transformer and switchgear enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding transformer and switchgear enclosures... MINES Electricity § 56.12026 Grounding transformer and switchgear enclosures. Metal fencing and metal buildings enclosing transformers and switchgear shall be grounded....

  10. 30 CFR 57.12026 - Grounding transformer and switchgear enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding transformer and switchgear enclosures... NONMETAL MINES Electricity Surface and Underground § 57.12026 Grounding transformer and switchgear enclosures. Metal fencing and metal buildings enclosing transformers and switchgear shall be grounded....

  11. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.

    2010-01-01

    Repetitive long term formalin application at low dose was investigated to determine the effect on formaldehyde removal rate, biofilter nitrification and the microbial composition in small-scale recirculation aquaculture biofilters. Six pilot-scale recirculation aquaculture systems holding rainbow...... Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since...

  12. Humidity evolution (breathing effect) in enclosures with electronics

    DEFF Research Database (Denmark)

    Hygum, Morten Arnfeldt; Popok, Vladimir

    2015-01-01

    Packaging and enclosures used for protecting power electronics operating outdoors are designed to withstand the local climatic and environmental changes. Hermetic enclosures are expensive and therefore other solutions for protecting the electronics from a harsh environment are required. One...... of the dangerous parameters is high humidity of air. Moisture can inevitable reach the electronics either due to diffusion through the wall of an enclosure or small holes, which are designed for electrical or other connections. A driving force for humid air movement is the temperature difference between...... the operating electronics and the surrounding environment. This temperature, thus, gives rise to a natural convection, which we also refer to as breathing. Robust and intelligent enclosure designs must account for this breathing as it can significantly change the humidity distribution in the enclosure...

  13. Husbandry and enclosure influences on penguin behavior and conservation breeding.

    Science.gov (United States)

    Marshall, Andrew R; Deere, Nicolas J; Little, Holly A; Snipp, Ross; Goulder, Jackie; Mayer-Clarke, Stacey

    2016-09-01

    Multi-zoo comparisons of animal welfare are rare, and yet vital for ensuring continued improvement of zoo enclosures and husbandry. Methods are not standardized for the development of zoo enclosures based on multiple indicators, and case study species are required. This study compares behavior and breeding success to various enclosure and husbandry parameters for the Humboldt penguin, Spheniscus humboldti, for the development of improved enclosure design. Behavioral sampling was completed at Flamingo Land over a period of 8 months. Further data on behavior, enclosure design, and breeding success were collected via questionnaires, visits to zoos, and literature review. Breeding success was primarily influenced by colony age and number of breeding pairs, suggesting an important social influence on reproduction. Across zoos, there was also significant variation in behavior. The proportion of time spent in water varied between zoos (2-23%) and was used as an indicator of physical activity and natural behavior. Regression models revealed that water-use was best predicted by total enclosure area per penguin, followed by land area, with some evidence for positive influence of pool surface area per penguin. Predominantly linear/curvilinear increases in our biological indicators with enclosure parameters suggest that optimal conditions for S. humboldti were not met among the selected zoos. We propose revised minimum conditions for S. humboldti enclosure design, which exceed those in the existing husbandry guidelines. We present a framework for the evaluation of zoo enclosures and suggest that a rigorous scientific protocol be established for the design of new enclosures, based on multivariate methods. Zoo Biol. 35:385-397, 2016. © Wiley Periodicals, Inc.

  14. Antimicrobial use and resistance in aquaculture: findings of a globally administered survey of aquaculture-allied professionals.

    Science.gov (United States)

    Tuševljak, N; Dutil, L; Rajić, A; Uhland, F C; McClure, C; St-Hilaire, S; Reid-Smith, R J; McEwen, S A

    2013-09-01

    There is limited published information regarding antimicrobial use (AMU) and antimicrobial resistance (AMR) in aquaculture. Our objective was to determine the opinions of aquaculture-allied professionals around the world on the frequency of AMU and AMR in common aquatic species. The study questionnaire included five sections: respondent demographics, extent of AMU in aquaculture, frequency of observations of AMR in aquaculture, AMR monitoring and surveillance and antimicrobial susceptibility testing in various jurisdictions. It was administered in English and Spanish to 604 professionals in 25 countries and with varying expertise in aquaculture. The response rate was 33% (199/604). Over half of the participants had >10 years of experience in aquaculture: 70% (140/199) were involved in fish health/clinical work and their primary experience was with salmon, tilapia, trout, shrimp (including prawn) and/or catfish. Tetracycline use was reported by 28%, 46%, 18%, 37% and 9% of respondents working with catfish, salmon, tilapia, trout and shrimp, respectively. Resistance to tetracycline in one or more species of bacteria was reported as 'frequent-to-almost always' for the same aquaculture species by 39%, 28%, 17%, 52% and 36% of respondents, respectively. 'Frequent-to-almost always' use of quinolone was reported by 70% (32/46) and 67% (8/12) of respondents from the United States and Canada, respectively, where quinolone products are not approved for aquaculture, and extra-label fluoroquinolone use is either prohibited (United States) or discouraged (Canada). Similar frequencies of quinolone use were also reported by the majority of respondents from Europe [70% (7/10)] and Asia [90% (9/10)] where labelled indications exist. This baseline information can be used to prioritize research or surveillance for AMU and AMR in aquaculture.

  15. Dependency on aquaculture in northern Vietnam

    DEFF Research Database (Denmark)

    Le Minh, Hanh; Phan, Van Thi; Nghia, Nguyen Huu

    2016-01-01

    diverse sources of income shows the unstable or risky nature of aquaculture livelihoods in the study area. Our findings suggest that policies promoting aquaculture should focus on training of farmers whilst acknowledging that a diverse income portfolio increases livelihood resilience to external shocks...... such as extreme weather events, diseases and fluctuating market prices....

  16. Aquaculture and food crisis: opportunities and constraints.

    Science.gov (United States)

    Liao, I Chiu; Chao, Nai-Hsien

    2009-01-01

    Fish farming, now well known as aquaculture, has been well recognized since the ancient era. The first written document on fish culture was published in China in 475 BC, and the first koi pond was constructed at the Japanese Imperial Palace grounds during 71-130 AD. In recent years, aquaculture has progressively played an important role in the provision of: animal protein and gourmet cuisines, job opportunities, and foreign currency for developing countries. Asian countries produce around 91 percent of the world's total aquaculture production. Among the top ten aquaculture-producing countries, nine are from Asia. The current global population consist of more than 6.5 billion individuals; over one billion of which face hunger problem. In the highly populated Asia-Pacific region with moderately high-productivity, 642 million people are still facing hunger. Being a proficient and potential source of animal protein, aquaculture will play an increasing and important role in solving the world food problem in the future. This paper discusses both the opportunities and constraints in the aquaculture industry, specifically in the Asia-Pacific region, and its possible role in solving the current global food crisis. Strategies including promotion and adoption of traceability and HACCP systems for food safety, and marketing management for aquaculture products are also suggested. It is hoped that traditional administration of aquaculture management for survival, profit, as well as food safety will successfully match sustainability management to meet the urgent global need for food.

  17. Consumer behaviour and preferences for aquaculture products

    DEFF Research Database (Denmark)

    Brunsø, Karen; Scholderer, Joachim; Verbeke, Wim

    During the last decades, the proportion of aquaculture products in the market place has increased dramatically and this trend seems to continue in the future as well. While both the producers of aquaculture products as well as the distribution channels are aware of this change in product...

  18. Exploring Aquaculture. Curriculum Guide for Agriscience 282.

    Science.gov (United States)

    Texas A and M Univ., College Station. Dept. of Agricultural Education.

    This curriculum guide provides materials for teachers to use in developing a course in "Exploring Aquaculture, Agriscience 282," one of 28 semester courses in agricultural science and technology for Texas high schools. This introductory course is designed to acquaint students with the growing industry of aquaculture; it includes…

  19. BIOTECHNOLOGY OF THE FISH AQUACULTURE

    Directory of Open Access Journals (Sweden)

    L. P. Buchatsky

    2013-12-01

    Full Text Available The latest progress in biotechnology on fish aquaculture and different modern methods of investigations for increasing of fish productivity in aquaculture are analyzed. Except for the applied aspect, the use of modern biotechnological methods of investigations opens new possibilities for fundamental researches of sex-determining mechanisms, polyploidy, distant hybridization, and developmental biology of bony fishes. Review contains examples of utilizing modern biotechnology methods to obtain transgenic fishes with accelerated growth and for designing surrogate fishes. Methods for receiving unisexual shoals of salmon and sturgeon female fishes with the view of obtaining a large quantity of caviar, as well as receiving sterile (triploid fishes are analyzed. Great attention is given to androgenesis, particularly to disperm one, in connection with the problem of conserving rare and vanishing fish species using only sperm genetic material. Examples how distant hybrids may be obtained with the use of disperm androgenesis and alkylated DNA are given. Methods of obtaining fish primordium germ cells, recent developments in cultivation of fish stem cells and their use in biotechnology, as well as ones of transplantation of oogonium and spermatogonium to obtain surrogate fishes. The examples of successful experiments on spermatogonial xenotransplantation and characteristic of antifreezing fish proteins and also the prospect of their practical usage are given.

  20. 黄土高原不同封育年限草地土壤与植物根系的生态化学计量特征%Ecological Stoichiometric Characteristics of Grassland Soils and Plant Roots Relative to Enclosure History on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    赵晓单; 曾全超; 安韶山; 方瑛; 马任甜

    2016-01-01

    [Objective]The knowledge about vegetation succession,is essential to vegetation restoration,especially in steppe regions on the Loess Plateau. Recently stoichiometry has been effectively used to illustrate plant community succession and vegetation restoration. Balance of carbon(C),nitrogen (N),and phosphorus(P)in plant has been a hotspot of the research on biogeochemical cycle and plant ecology. However,most of the studies have focused on nutrients in plant leaves,and few did on the elements in plant roots,let alone,on ecological stoichiometrical characteristics of the soils and plant roots in steppe regions under enclosure on the Loess Plateau,relative to enclosure history.[Method]This paper explored ecological stoichiometrical characteristics of the soils and plant roots in grasslands different in enclosure history(1 a,12 a,20 a and 30 a)on the Yunwu mountain of Ningxia Province. The steppe region under study is located between 106°26′E and 106°30′E and between 35°59′N and 36°02′N. The YunwuMountain lies across the center of the Loess Plateau,with an altitude ranging from 1 000 to 1 800 m above sea level. The study area has a semi-arid climate,characterized by heavy seasonal rainfalls causing recurrent flooding and drought,with mean annual temperature being 5 ℃ and mean annual precipitation being 445 m. The typical natural vegetation of this region is grassland. Samples of the soils and plant roots in the region were collected and analyzed for organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP),and their stoichiometrical ratio and interrelationships,using the time-space substitution method,based on the principles of stoichiometry.[Result]Result show that with the enclosure going on, soil bulk density decreased gradually,SOC and TN varied more significantly,while TP did less. In the early years of enclosure,SOC and TN declined first and then rose till the enclosure reached 20 or 30 years old,when they leveled off. Soil organic carbon

  1. 76 FR 9209 - Draft NOAA National Aquaculture Policy

    Science.gov (United States)

    2011-02-16

    ... National Aquaculture Policy and Draft DOC National Aquaculture Policy; Notices #0;#0;Federal Register / Vol... and Atmospheric Administration RIN 0648-XA214 Draft NOAA National Aquaculture Policy AGENCY: National...: Notice of availability of draft aquaculture policy; request for comments. SUMMARY: NOAA is seeking...

  2. REVIEW OF AQUACULTURE GENETIC RESEARCHES IN THAILAND

    Directory of Open Access Journals (Sweden)

    UTHAIRAT NA-NAKORN

    1992-01-01

    Full Text Available Aquaculture business has been well established in Thailand for more than 40 years. The most recent data indicated a total production of 260 380 tons. Sixty-five percent of the total production came from coastal aquaculture, mainly tiger prawn (Penaeus monodon culture. Other important species for coastal aquaculture are banana prawn (P. merguensis, cockle (Anadara granosa, green mussel (Perna viridis, oyster (Crassostrea belcheri, Saccostrea commercialis, sea bass (Lates calcarifer and grouper (Epinephelus tauvina. Freshwater aquaculture, although produced only 35% of the annual production, provides major protein source for people in rural areas. Important freshwater species are Nile tilapia (Oreochromis niloticus, tawes (Puntius gonionotus, sepat Siam (Trichogasterpectoralis, walking catfish (Glorias spp., stripped catfish (Pangasius sutchi and giant freshwater prawn (Macrobrachium rosenbergii. Optimum aquacultural practises, namely stocking density, nutrition requirement and water quality have been obtained in most cultured species. But genetic approach has not been considered, thus resulting in deterioration in economic traits which might be due to excessive inbreeding (reviewed by Uraiwan 1989 and/or negative selection (Wongsangchan 1985. The history of researches on genetics in aquaculture in Thailand started in 1982 when the aquaculture genetic programme in form of a network has been established at the National Inland Fisheries Institute, Department of Fisheries. This programme was supported by the International Development Research Centre (IDRC, Canada in cooperation with Dalhousie University, Canada (Uraiwan 1989. In the same year a genetic improvement programme aiming at improving economic characters of some economic fish species has been conducted at the Department of Aquaculture, Kasetsart University. Paralelly a course in Fish Genetics has been offered. Since then different approaches of genetics have been applied with final

  3. Aquaculture: global status and trends.

    Science.gov (United States)

    Bostock, John; McAndrew, Brendan; Richards, Randolph; Jauncey, Kim; Telfer, Trevor; Lorenzen, Kai; Little, David; Ross, Lindsay; Handisyde, Neil; Gatward, Iain; Corner, Richard

    2010-09-27

    Aquaculture contributed 43 per cent of aquatic animal food for human consumption in 2007 (e.g. fish, crustaceans and molluscs, but excluding mammals, reptiles and aquatic plants) and is expected to grow further to meet the future demand. It is very diverse and, contrary to many perceptions, dominated by shellfish and herbivorous and omnivorous pond fish either entirely or partly utilizing natural productivity. The rapid growth in the production of carnivorous species such as salmon, shrimp and catfish has been driven by globalizing trade and favourable economics of larger scale intensive farming. Most aquaculture systems rely on low/uncosted environmental goods and services, so a critical issue for the future is whether these are brought into company accounts and the consequent effects this would have on production economics. Failing that, increased competition for natural resources will force governments to allocate strategically or leave the market to determine their use depending on activities that can extract the highest value. Further uncertainties include the impact of climate change, future fisheries supplies (for competition and feed supply), practical limits in terms of scale and in the economics of integration and the development and acceptability of new bio-engineering technologies. In the medium term, increased output is likely to require expansion in new environments, further intensification and efficiency gains for more sustainable and cost-effective production. The trend towards enhanced intensive systems with key monocultures remains strong and, at least for the foreseeable future, will be a significant contributor to future supplies. Dependence on external feeds (including fish), water and energy are key issues. Some new species will enter production and policies that support the reduction of resource footprints and improve integration could lead to new developments as well as reversing decline in some more traditional systems.

  4. Recovering and Mining Asteroids with a Gas-Sealed Enclosure

    Science.gov (United States)

    Jenniskens, P.; Damer, B.; Norkus, R.; Pilotz, S.; Grigsby, B.; Adams, C.; Blair, B. R.

    2015-01-01

    The internal structure of weakly consolidated rubble piles and primitive asteroids can be studied closer to home, and such asteroids can be mined, if it is possible to create a gas-sealed enclosure around the asteroid.

  5. 30 CFR 18.31 - Enclosures-joints and fastenings.

    Science.gov (United States)

    2010-07-01

    ... Volume Volume of empty enclosure Less than 45 cu. in. 45 to 124 cu. in. inclusive More than 124 cu. in... closed with a plug secured by weld or braze. Bolts shall be provided at all corners. 8 The...

  6. Application of solar hot water and geothermal principles to closed-cycle aquaculture

    Science.gov (United States)

    Yanzito, R. A.

    1981-04-01

    The design of an underground silo where warm water food fish could be raised to market size under controlled conditions. The building and solar concept analysis for the closed cycle aquaculture system are described. Energy conservation features of the design include Earth berming and insulation of the production silo and enclosure, a waste water reclaim system and a solar heating system. Much of the water surface area is covered with removable plants to minimize evaporative heat losses. An energy conservation analysis is also reported and the F-Chart computer program is described. The system chosen utilizes single glazed flat plate collectors in a closed loop antifreeze system. Makeup water is introduced during an 8 hour period each day. Solar energy is transferred from the antifreeze solution to the makeup water after it leaves the waste water heat exchanger.

  7. Humidity Buildup in Electronic Enclosures Exposed to Constant Conditions

    DEFF Research Database (Denmark)

    Conseil, Helene; Staliulionis, Zygimantas; Jellesen, Morten Stendahl;

    2017-01-01

    Electronic components and devices are exposed to a wide variety of climatic conditions, therefore the protection of electronic devices from humidity is becoming a critical factor in the system design. The ingress of moisture into typical electronic enclosures has been studied with defined....... The moisture buildup inside the enclosure has been simulated using an equivalent RC circuit consisting of variables like controlled resistors and capacitors to describe the diffusivity, permeability, and storage in polymers....

  8. Development and validation of a radioimmunoassay for fish insulin-like growth factor I (IGF-I) and the effect of aquaculture related stressors on circulating IGF-I levels.

    Science.gov (United States)

    Dyer, Anthony R; Upton, Zee; Stone, David; Thomas, Philip M; Soole, Kathleen L; Higgs, Naomi; Quinn, Kirsty; Carragher, John F

    2004-02-01

    This paper describes the development and validation of a commercially available radioimmunoassay (RIA) for the detection of fish insulin-like growth factor-I (IGF-I). The assay was developed using recombinant barramundi IGF-I as antigen and recombinant tuna IGF-I as radiolabelled tracer and standard. Assay sensitivity was 0.15 ng/ml, inter-assay variation was 16% (n = 9) and intra-assay variation was 3% (n = 10). Cross reactivity of less than 0.01% was found with salmon insulin, salmon IGF-II and barramundi IGF-II, less than 0.5% with human IGF-I and less than 1% with human IGF-II. Parallel dose-response inhibition curves were shown for barramundi (Lates calcarifer), coho salmon (Oncorhynchus kisutch), Southern Bluefin tuna (Thunnus maccoyii), tilapia (Oreochromis mossambicus), and seabream (Pagrus auratus) IGF-I. The assay was then used to measure stress related changes in different aquacultured fish species. Salt water acclimated Atlantic salmon smolts (Salmo salar) bathed for 2 h in fresh water showed significantly lower IGF-I concentrations than control smolts two days after the bath (53.1 compared to 32.1 ng/ml), with levels of IGF-I also lower in smolts exhibiting stunted growth (stunts). Capture and confinement of wild tuna in sea-cages resulted in a significant decrease in IGF-I levels (28 ng/ml) when compared to tuna captured and sampled immediately (48 ng/ml), but had recovered to starting levels after 3 weeks (43 ng/ml). Handling and isolation in silver perch (Bidyanus bidyanus) led to a gradual decline in IGF-I over a 12 h period (36-19 ng/ml) but showed signs of recovery by 24 h (24 ng/ml) and had recovered fully 72 h after treatment (40 ng/ml). A similar trial in black bream (Acanthopagrus butcherii) showed comparable results with IGF-I levels gradually decreasing (40-26 ng/ml) over 24 h, results that were mirrored by cortisol concentrations which increased during this time (1-26 ng/ml). In the studies presented here changes in IGF-I levels were not

  9. Aquaculture in Coastal and Marine US Waters

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, mollusks, and aquatic plants. The presence and location of...

  10. Hydrogen peroxide decomposition kinetics in aquaculture water

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2015-01-01

    Hydrogen peroxide (HP) is used in aquaculture systems where preventive or curative water treatments occasionally are required. Use of chemical agents can be challenging in recirculating aquaculture systems (RAS) due to extended water retention time and because the agents must not damage the fish...... reared or the nitrifying bacteria in the biofilters at concentrations required to eliminating pathogens. This calls for quantitative insight into the fate of the disinfectant residuals during water treatment. This paper presents a kinetic model that describes the HP decomposition in aquaculture water...... the enzyme activity. This was, however, not measured. The model developed successfully described the removal of HP in aquaculture water from three types of RAS and model parameters are estimated. The model and the model parameters provide new information and are valuable tools to improve HP application...

  11. Reproduction of European Eel in Aquaculture (REEL)

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Tybjerg, Lars; Støttrup, Josianne

    Project aim: Enhance methods and technology applied to produce and culture European eel larvae as basis for the development of a future self-sustained eel aquaculture. Background: The severe decline of the European eel stock calls for conservation measures including national eel management plans...... and establishment of a self-sustained eel aquaculture. In 2005, the National Institute of Aquatic Resources at the Technical University of Denmark (DTU Aqua), the Faculty of Life Sciences at Copenhagen University (KU-Life) and the eel aquaculture industry started to build up a research and technology platform...... for the development of methods to reproduce European eel in aquaculture. Two major projects: Artificial Reproduction of Eels II and III (ROE II and III) succeeded during 2005-2008 to produce viable eggs and larvae that lived up to 12 days. The larvae thereby accomplished the yolk-sac stage and became ready to start...

  12. A Comparison between America and Other Countries in Offshore Aquaculture Management:a Literature Review

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>In America offshore aquaculture is gaining momentum in recent years,and expects to grow faster in the near future.The White House has clearly expressed its support;statistics show that the aquaculture has huge potential and can contribute a lot to employment and help reducing the trade deficit;the offshore aquaculture act which is designed to promote American offshore aquaculture industry has been proposed to the Congress for action.However,there are still some long standing obstacles hindering its development such as competing uses, wasted pollutants,lacking of fishing food,escapees,GMOs,lengthy permission procedures etc.Ironically,to some of these issues,debates have been there for decades without consensus.While the proposed National Offshore Aquaculture Act 2005 may provide major principles for the solution to these problems,it is also useful to draw experiences from some other countries that have longer history and more advanced skills in the industry.Their technology and institutional design are prone to the development of their aquaculture industries.Mainly this paper,as a literature review,examines the practices of Norway,Canada and Australia, and compares their actions with the real problems in U.S.,and what has been proposed by National Offshore Aquaculture Act 2005.This paper aims to check what other nations have done with these problems,draw useful experiences from them,analyze what the Offshore Aquaculture Act has achieved,and recommend what the related federal agencies should do in the next step.

  13. An assessment of some non-gray global radiation models in enclosures

    Science.gov (United States)

    Meulemans, J.

    2016-01-01

    The accuracy of several non-gray global gas/soot radiation models, namely the Wide-Band Correlated-K (WBCK) model, the Spectral Line Weighted-sum-of-gray-gases model with one optimized gray gas (SLW-1), the (non-gray) Weighted-Sum-of-Gray-Gases (WSGG) model with different sets of coefficients (Smith et al., Soufiani and Djavdan, Taylor and Foster) was assessed on several test cases from the literature. Non-isothermal (or isothermal) participating media containing non-homogeneous (or homogeneous) mixtures of water vapor, carbon dioxide and soot in one-dimensional planar enclosures and multi-dimensional rectangular enclosures were investigated. For all the considered test cases, a benchmark solution (LBL or SNB) was used in order to compute the relative error of each model on the predicted radiative source term and the wall net radiative heat flux.

  14. Radiative and free-convective heat transfer from a finite horizontal plate inside an enclosure

    Science.gov (United States)

    Hrycak, Peter; Sandman, D. J.

    1986-01-01

    An experimental and analytical investigation of heat transfer from a horizontal, thin, square plate inside of an enclosure was carried out. Experimental results were obtained from both the upward-facing and the downward-facing sides of the heated plate. Starting with the integrated momentum and energy equations, approximate solutions were obtained for heat transfer in the laminar and the turbulent regime that correlate well with experimental data. Radiative heat transfer correction was given special attention. Effects of the enclosure-related recirculation of the test fluid, as well as effects of simultaneous heat transfer on both sides of the plate, caused an early transition, and indicated a high level of internal turbulence.

  15. Influence of uniform magnetic field on laminar regimes of natural convection in an enclosure

    Science.gov (United States)

    Bondareva, N. S.; Sheremet, M. A.

    2015-03-01

    A numerical analysis of spatial laminar regimes of natural convection in an enclosure is conducted in the presence of a uniform magnetic field. The mathematical model formulated in dimensionless natural variables "velocity-pressure-temperature" has been implemented numerically by the method of control volume. The influence of the Rayleigh number (103 ≤ Ra ≤ 105) and the Hartmann number (0 ≤ Ha ≤ 100), the orientation of the magnetic induction vector (0 ≤ φ ≤ π/2) as well as of the geometric parameter (0.2 ≤ A ≤ 5), which reflects the enclosure relative length, on the velocity and temperature distributions as well as the average Nusselt number on a typical isothermal boundary has been studied in detail. A possibility of describing the integral heat exchange in the spatial object under consideration on the basis of the two-dimensional model has been established.

  16. Dialectic Form Finding of Passive and Adaptive Shading Enclosures

    Directory of Open Access Journals (Sweden)

    Sigrid Adriaenssens

    2014-08-01

    Full Text Available Form finding describes the process of finding a stable equilibrium shape for a system under a specific set of loads, for a set of boundary conditions and starting from an arbitrary initial geometry. However, form finding does not traditionally involve performance constraints such as energy-related criteria. Dialectic form finding is an extension of the process integrating energy-related design aspects. In this paper, dialectic form finding is employed as an approach for designing high performance architectural systems, driven by solar radiation control and structural efficiency. Two applications of dialectic form found shading enclosure structures, a passive and an active one, are presented. The first application example is a site-specific outdoor shading structure. The structure is based on a louver system designed to provide protection from ultraviolet radiation over a pre-defined target only when required, promoting natural lighting and ventilation. The second application example is a shape-shifting modular façade system that adapts its opacity in response to environmental fluctuations. The system can thus improve the environmental performance of a building. Moreover, the system explores elastic deformations for shape changes, reducing actuation requirements. These examples highlight the potential of the dialectic form-finding strategy for the design of high performance architectural integrated structures.

  17. Application of Constructed Wetlands on Wastewater Treatment for Aquaculture Ponds

    Institute of Scientific and Technical Information of China (English)

    LI Gu; WU Zhenbin; CHENG Shuiping; LIANG Wei; HE Feng; FU Guiping; ZHONG Fei

    2007-01-01

    A group of constructed wetlands (CWs) were applied to the recirculating aquaculture system. This study assessed the performance of CWs in treating the aquaculture wastewater, examined the water quality condition of aquaculture ponds and the growth and the survival rate of "target" species(Ictalurus punctatus and Megalobrama amblycephala). The results showed that CWs were effective on reducing the concentrations of 5-day biochemical oxygen demand (BOD5, at 70.5%), total suspended solids (TSS, at 81.9%),chlorophyll a (Chl-a, at 91.9%), ammonium (NH4+, at 61.5%) and nitrate nitrogen (NO3--N, at 68.0%). Effect of CWs on phosphate (PO43- -P) removal was relatively lower (at 20.0%). The concentrations of BOD5, TSS, Chl-a, NH4+ and TN, TP in the recirculating culture pond were significantly lower than that in the control pond( p < 0.05 ). CWs could help to increase total yield, survival rate of the "target" species and significantly decrease feed conversion ratio ( p < 0.05 ).

  18. Review of occupational hazards associated with aquaculture.

    Science.gov (United States)

    Myers, Melvin L

    2010-10-01

    Aquaculture is an emerging sector that is associated with most of the same hazards that are present in agriculture generally, but many fish farming tasks entail added danger, including working around water and working at night. Comprehensive studies of these hazards have not been conducted, and substantial uncertainty exists as to the extent of these hazards. The question addressed in this investigation was, "What is known about potential hazardous occupational exposures to aquatic plant and animal farmers?" In this review, causes of death included drowning, electrocution, crushing-related injury, hydrogen sulfide poisoning, and fatal head injury. Nonfatal injuries were associated with slips, trips, and falls; machines; strains and sprains; chemicals; and fires. Risk factors included cranes (tip over and power line contact), tractors and sprayer-equipped all-terrain vehicles (overturn), heavy loads (lifting), high-pressure sprayers, slippery surfaces, rotting waste (hydrogen sulfide production), eroding levees (overturn hazard), storm-related rushing water, diving conditions (bends and drowning), nighttime conditions, working alone, lack of training, lack of or failure to use personal flotation devices, and all-terrain vehicle speeding. Other hazards included punctures or cuts from fish teeth or spines, needlesticks, exposure to low temperatures, and bacterial and parasitic infections .

  19. Public Perceptions of Aquaculture: Evaluating Spatiotemporal Patterns of Sentiment around the World

    Science.gov (United States)

    Froehlich, Halley E.; Gentry, Rebecca R.; Rust, Michael B.; Grimm, Dietmar; Halpern, Benjamin S.

    2017-01-01

    Aquaculture is developing rapidly at a global scale and sustainable practices are an essential part of meeting the protein requirements of the ballooning human population. Locating aquaculture offshore is one strategy that may help address some issues related to nearshore development. However, offshore production is nascent and distinctions between the types of aquatic farming may not be fully understood by the public–important for collaboration, research, and development. Here we evaluate and report, to our knowledge, the first multinational quantification of the relative sentiments and opinions of the public around distinct forms of aquaculture. Using thousands of newspaper headlines (Ntotal = 1,596) from developed (no. countries = 26) and developing (42) nations, ranging over periods of 1984 to 2015, we found an expanding positive trend of general ‘aquaculture’ coverage, while ‘marine’ and ‘offshore’ appeared more negative. Overall, developing regions published proportionally more positive than negative headlines than developed countries. As case studies, government collected public comments (Ntotal = 1,585) from the United States of America (USA) and New Zealand mirrored the media sentiments; offshore perception being particularly negative in the USA. We also found public sentiment may be influenced by local environmental disasters not directly related to aquaculture (e.g., oil spills). Both countries voiced concern over environmental impacts, but the concerns tended to be more generalized, rather than targeted issues. Two factors that could be inhibiting informed discussion and decisions about offshore aquaculture are lack of applicable knowledge and actual local development issues. Better communication and investigation of the real versus perceived impacts of aquaculture could aid in clarifying the debate about aquaculture, and help support future sustainable growth. PMID:28046057

  20. Optimization of natural convection heat transfer of Newtonian nanofluids in a cylindrical enclosure

    Institute of Scientific and Technical Information of China (English)

    Hamid Moradi; Bahamin Bazooyar; Ahmad Moheb; Seyed Gholamreza Etemad

    2015-01-01

    This study characterizes and optimizes natural convection heat transfer of two Newtonian Al2O3 and TiO2/water nanofluids in a cylindrical enclosure. Nusselt number (Nu) of nanofluids in relation to Rayleigh number (Ra) for different concentrations of nanofluids is investigated at different configurations and orientations of the enclosure. Results show that adding nanoparticles to water has a negligible or even adverse influence upon natural convec-tion heat transfer of water:only a slight increase in natural convection heat transfer of Al2O3/water is observed, while natural convection heat transfer for TiO2/water nanofluid is inferior to that for the base fluid. Results also reveal that at low Ra, the likelihood of enhancement in natural convection heat transfer is more than at high Ra:at low Ra, inclination angle, aspect ratio of the enclosure and nanoparticle concentration influence natural convec-tion heat transfer more pronouncedly than that in high Ra.

  1. Determination of 4-nonylphenol concentrations in sediment from a littoral enclosure study

    Energy Technology Data Exchange (ETDEWEB)

    Sheedy, B.R. [Integrated Lab. Systems, Duluth, MN (United States); Heinis, L.J. [Univ. of Wisconsin, Superior, WI (United States); Knuth, M.L.; Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1994-12-31

    During the summer of 1993, a small pond, divided into 18 littoral enclosures was dosed for 21 days with the industrial surfactant metabolite, 4-nonylphenol (NP). A team of biologists and chemists monitored the biological and chemical parameters in each littoral enclosure during the dosing period and for several months thereafter. The water column NP concentrations (nominal 0, 3, 30, 1 00 and 300 ppb) remained relatively constant throughout the dosing period and decreased dramatically during the post-dose phase Natural sediment concentrations, determined during the post-dose phase, in most cases remained high, especially at the 300 ppb level. Artificial containers of sediment placed in several enclosures had somewhat lesser concentrations than the natural sediment. Over the six week sampling period (post-dose), the natural sediment concentrations dropped off, but were still significant at 63 days post-dose. This NP disappearance was small in comparison to the disappearance of NP from the water column. Sediment interstitial NP concentrations were not detected. Concentrations of NP in the sediment after winter will be determined and discussed.

  2. Numerical simulation of transient moisture and temperature distribution in polycarbonate and aluminum electronic enclosures

    DEFF Research Database (Denmark)

    Shojaee Nasirabadi, Parizad; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

    2016-01-01

    ) analysis has been proven as a useful tool to exploit the detailed and visualized information about the fluid flows; and hence it can be helpful for predicting local climate inside the electronic enclosures. In this study, the temperature and moisture distributions inside an idealized electronic enclosure...... with some heat producing components are investigated. It is shown how the enclosure material can influence local climate inside the enclosure using transient numerical simulations. The effect of heat transfer coefficient and wall thickness of the enclosure is also investigated. The enclosure material...

  3. The OMEGA system for marine bioenergy, wastewater treatment, environmental enhancement, and aquaculture

    Science.gov (United States)

    Trent, J. D.

    2013-12-01

    OMEGA is an acronym for Offshore Membrane Enclosure for Growing Algae. The OMEGA system consists of photobioreactors (PBRs) made of flexible, inexpensive clear plastic tubes attached to floating docks, anchored offshore in naturally or artificially protected bays [1]. The system uses domestic wastewater and CO2 from coastal facilities to provide water, nutrients, and carbon for algae cultivation [2]. The surrounding seawater maintains the temperature inside the PBRs and prevents the cultivated (freshwater) algae from becoming invasive species in the marine environment (i.e., if a PBR module accidentally leaks, the freshwater algae that grow in wastewater cannot survive in the marine environment). The salt gradient between seawater and wastewater is used for forward osmosis (FO) to concentrate nutrients and facilitate algae harvesting [3]. Both the algae and FO clean the wastewater, removing nutrients as well as pharmaceuticals and personal-care products [4]. The offshore infrastructure provides a large surface area for solar-photovoltaic arrays and access to offshore wind or wave generators. The infrastructure can also support shellfish, finfish, or seaweed aquaculture. The economics of the OMEGA system are supported by a combination of biofuels production, wastewater treatment, alternative energy generation, and aquaculture. By using wastewater and operating offshore from coastal cities, OMEGA can be located close to wastewater and CO2 sources and it can avoid competing with agriculture for water, fertilizer, and land [5]. By combining biofuels production with wastewater treatment and aquaculture, the OMEGA system provides both products and services, which increase its economic feasibility. While the offshore location has engineering challenges and concerns about the impact and control of biofouling [6], large OMEGA structure will be floating marine habitats and will create protected 'no-fishing' zones that could increase local biodiversity and fishery

  4. Photodynamic antimicrobial chemotherapy in aquaculture: photoinactivation studies of Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Eliana Alves

    Full Text Available BACKGROUND: Photodynamic antimicrobial chemotherapy (PACT combines light, a light-absorbing molecule that initiates a photochemical or photophysical reaction, and oxygen. The combined action of these three components originates reactive oxygen species that lead to microorganisms' destruction. The aim was to evaluate the efficiency of PACT on Vibrio fischeri: 1 with buffer solution, varying temperature, pH, salinity and oxygen concentration values; 2 with aquaculture water, to reproduce photoinactivation (PI conditions in situ. METHODOLOGY/PRINCIPAL FINDINGS: To monitor the PI kinetics, the bioluminescence of V. fischeri was measured during the experiments. A tricationic meso-substituted porphyrin (Tri-Py(+-Me-PF was used as photosensitizer (5 µM in the studies with buffer solution and 10-50 µM in the studies with aquaculture water; artificial white light (4 mW cm(-2 and solar irradiation (40 mW cm(-2 were used as light sources; and the bacterial concentration used for all experiments was ≈10(7 CFU mL(-1 (corresponding to a bioluminescence level of 10(5 relative light units--RLU. The variations in pH (6.5-8.5, temperature (10-25°C, salinity (20-40 g L(-1 and oxygen concentration did not significantly affect the PI of V. fischeri, once in all tested conditions the bioluminescent signal decreased to the detection limit of the method (≈7 log reduction. The assays using aquaculture water showed that the efficiency of the process is affected by the suspended matter. Total PI of V. fischeri in aquaculture water was achieved under solar light in the presence of 20 µM of Tri-Py(+-Me-PF. CONCLUSIONS/SIGNIFICANCE: If PACT is to be used in environmental applications, the matrix containing target microbial communities should be previously characterized in order to establish an efficient protocol having into account the photosensitizer concentration, the light source and the total light dose delivered. The possibility of using solar light in PACT to

  5. Standard Guide for Testing Materials for Aerospace Plastic Transparent Enclosures

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This guide is intended to summarize the standard test methods available on individual and composite materials utilized in fabrication of aerospace plastic transparent enclosures. As such, it is intended to specifically include transparent thermoplastics, transparent elastomers, and reinforced plastics, whether thermoplastic or thermosetting. 1.2 This guide is intended as an aid in the search for test methods pertinent to Aerospace Plastic Transparent Enclosures. It should be understood that all methods listed may not apply to all enclosures. 1.3 The standards included refer to the properties or aspects listed in Table 1. The properties or aspects are listed in alphabetical order and the descriptions used are intended to facilitate the search. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limi...

  6. Sound reduction by metamaterial-based acoustic enclosure

    Directory of Open Access Journals (Sweden)

    Shanshan Yao

    2014-12-01

    Full Text Available In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

  7. Sound equalization in a large region of a rectangular enclosure

    DEFF Research Database (Denmark)

    Sarris, John C.; Jacobsen, Finn; Cambourakis, Georg E.

    2004-01-01

    The work presented by Santillán [J. Acoust. Soc. Am. 110, 1989–1997 (2001)] about equalization at low frequencies in rectangular enclosures is extended, and topics that remained unaddressed in the original study are treated in this paper. A modification is introduced to the original cost function...... the dependence of the limits of the zone of equalization on factors such as the damping constant of the modes of the enclosure, the number of sources, and the driving frequency. ©2004 Acoustical Society of America.......The work presented by Santillán [J. Acoust. Soc. Am. 110, 1989–1997 (2001)] about equalization at low frequencies in rectangular enclosures is extended, and topics that remained unaddressed in the original study are treated in this paper. A modification is introduced to the original cost function...

  8. An Overview of Aquaculture in the Nordic Countries

    DEFF Research Database (Denmark)

    Paisley, Larry; Ariel, Ellen; Lyngstad, T. M.

    2010-01-01

    The goal of this review was to describe in some detail the Nordic aquaculture industries in order to illuminate the similarities and differences. Information that was gathered for each country includes aquaculture history, aquaculture acts and regulations, production and production systems......, environmental concerns, organic aquaculture and outlook for the future. The information will be useful for risk assessments, design of risk-based surveillance programs and for construction of comparative risk profiles for endemic and exotic diseases affecting aquaculture in the Nordic countries. Aquaculture...... char and cod are most important in Iceland. Other important cultured species include eel and blue mussels. There is much diversity in Nordic aquaculture industries in terms of production, farmed species, and production systems. Although the vast majority of the Nordic aquaculture production...

  9. Computation of mixing in large stably stratified enclosures

    Science.gov (United States)

    Zhao, Haihua

    This dissertation presents a set of new numerical models for the mixing and heat transfer problems in large stably stratified enclosures. Basing on these models, a new computer code, BMIX++ (Berkeley mechanistic MIXing code in C++), was developed by Christensen (2001) and the author. Traditional lumped control volume methods and zone models cannot model the detailed information about the distributions of temperature, density, and pressure in enclosures and therefore can have significant errors. 2-D and 3-D CFD methods require very fine grid resolution to resolve thin substructures such as jets, wall boundaries, yet such fine grid resolution is difficult or impossible to provide due to computational expense. Peterson's scaling (1994) showed that stratified mixing processes in large stably stratified enclosures can be described using one-dimensional differential equations, with the vertical transport by free and wall jets modeled using standard integral techniques. This allows very large reductions in computational effort compared to three-dimensional numerical modeling of turbulent mixing in large enclosures. The BMIX++ code was developed to implement the above ideas. The code uses a Lagrangian approach to solve 1-D transient governing equations for the ambient fluid and uses analytical models or 1-D integral models to compute substructures. 1-D transient conduction model for the solid boundaries, pressure computation and opening models are also included to make the code more versatile. The BMIX++ code was implemented in C++ and the Object-Oriented-Programming (OOP) technique was intensively used. The BMIX++ code was successfully applied to different types of mixing problems such as stratification in a water tank due to a heater inside, water tank exchange flow experiment simulation, early stage building fire analysis, stratification produced by multiple plumes, and simulations for the UCB large enclosure experiments. Most of these simulations gave satisfying

  10. Streptomyces bacteria as potential probiotics in aquaculture

    Directory of Open Access Journals (Sweden)

    Tan Loh eTeng Hern

    2016-02-01

    Full Text Available In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effective in improving the growth, survival and health status of the aquatic livestock. This review aims to highlight the genus Streptomyces can be a good candidate for probiotics in aquaculture. Studies showed that the feed supplemented with Streptomyces could protect fish and shrimp from pathogens as well as increase the growth of the aquatic organisms. Furthermore, the limitations of Streptomyces as probiotics in aquaculture is also highlighted and solutions are discussed to these limitations.

  11. Modern aquaculture practices for increased fish production in Nigeria

    OpenAIRE

    Otubusin, S.O.

    1986-01-01

    Various modern aquaculture practices applied in fish production especially in Asia are reviewed. The vast Nigerian aquatic medium of numerous water bodies like rivers, streams, lakes reservoirs, flood plains, irrigation canals, coastal swamps offer great potentials for aquaculture production, if optimally utilized. Constraints to modernization of aquaculture in Nigeria among other factors are: 1) a serious shortage of trained manpower; 2) lack of knowledge on profitability of aquaculture as a...

  12. Genomic approaches in aquaculture and fisheries

    DEFF Research Database (Denmark)

    Cancela, M. Leonor; Bargelloni, Luca; Boudry, Pierre

    2010-01-01

    Despite the enormous input into the worldwide development of fish and shellfish farming in the recent decades, in part as an attempt to minimize the impact of fishing on already overexploited natural populations, the application of genomics to aquaculture and fisheries remains poorly developed....... Improving state-of-the-art genomics research in various aquaculture systems, as well as its industrial applications, remains one of the major challenges in this area and should be the focus of well developed strategies to be implemented in the next generation of projects. This chapter will first provide...

  13. A Research Update for the Stuttgart National Aquaculture Research Center

    Science.gov (United States)

    Aquaculture (fish farming) has played an ever-increasing role in providing people with fish, shrimp, and shellfish. Aquaculture is currently the fastest growing sector of global food production and in 2014 totaled 80 million tons valued at $140 billion. The production of food-fish from aquaculture...

  14. 7 CFR 1437.303 - Aquaculture, including ornamental fish.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Aquaculture, including ornamental fish. 1437.303... ASSISTANCE PROGRAM Determining Coverage Using Value § 1437.303 Aquaculture, including ornamental fish. (a) Aquaculture is a value loss crop and is compensable only in accord with restrictions set in this...

  15. Assessing the Aquaculture Curricula in the Northeastern Region.

    Science.gov (United States)

    Wingenbach, Gary J.; Gartin, Stacy A.; Lawrence, Layle D.

    2000-01-01

    Survey responses from 70 secondary agriculture teachers who included aquaculture in the curriculum indicated they averaged 4.5 years experience teaching aquaculture. Limited facilities, equipment costs, and low teacher knowledge were barriers. Only eight had used all of the aquaculture curriculum materials from the National Council for…

  16. Microbial eukaryotic community in response to Microcystis spp. bloom, as assessed by an enclosure experiment in Lake Taihu, China.

    Science.gov (United States)

    Chen, Meijun; Chen, Feizhou; Xing, Peng; Li, Huabing; Wu, Qinglong L

    2010-10-01

    Mesocosm experiments were carried out to examine the potential impacts of Microcystis blooms on microbial eukaryotic community composition (MECC). Four treatment additions of differing Microcystis spp. biomass were performed in enclosures, as indicated by chlorophyll a concentrations from 15 to 3217 μg L(-1) in the water column. Dialysis bags were used in enclosures to measure MECC dynamics without influence from predation and irradiance. Samples were taken on days 0, 1 and 4 for MECC analysis, based on changes in the chemical parameters during simultaneous monitoring. The MECC were determined by terminal restriction fragment length polymorphism (T-RFLP), followed by cloning and sequencing of 18S rRNA genes of selected samples. T-RFLP and clone library analysis revealed that MECC in enclosures and dialysis bags shifted strongly during Microcystis spp. decomposition. Members belonging to fungi became the dominant organisms in enclosures with a high biomass of Microcystis spp. Canonical correspondence analysis indicated that temporal changes in MECC were mostly related to changes in the pH and concentrations of dissolved oxygen and dissolved organic carbon, which were induced by the addition of Microcystis spp. The experiment suggests that accumulation of Microcystis biomass can strongly impact MECC, and there might be a saprophytic association between fungi and the decomposition of Microcystis biomass.

  17. Measure Guideline: Deep Energy Enclosure Retrofit for Double-Stud Walls

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-06-01

    This Measure Guideline describes a deep energy enclosure retrofit (DEER) solution that provides insulation to the interior of the wall assembly with the use of a double stud wall. The guide describes two approaches to retrofitting the existing the walls: one involving replacement of the existing cladding, and the other that leaves the existing cladding in place. It discusses the design principles related to the use of various insulation types, and provides strategies and procedures for implementing the double stud wall retrofit. It also evaluates important moisture-related and indoor air quality measures that need to be implemented to achieve a durable, high performance wall.

  18. Measure Guideline: Deep Energy Enclosure Retrofit for Double-Stud Walls

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-06-22

    This Measure Guideline describes a deep energy enclosure retrofit solution that provides insulation to the interior of the wall assembly with the use of a double-stud wall. The guide describes two approaches to retrofitting the existing walls—one that involves replacing the existing cladding and the other that leaves the cladding in place. This guideline also covers the design principles related to the use of various insulation types and provides strategies and procedures for implementing the double-stud wall retrofit. It also includes an evaluation of important moisture-related and indoor air quality measures that need to be implemented to achieve a durable high-performance wall.

  19. The diversity and distribution of anammox bacteria in the marine aquaculture zones.

    Science.gov (United States)

    Li, Meng; Gu, Ji-Dong

    2016-10-01

    The accumulation of toxic inorganic nitrogen is one of the major water quality problems in intensive aquaculture systems, thus the N removal in aquaculture systems is an important issue for the sustainable development of aquaculture. To understand one of the major microbial N removal processes, anaerobic ammonium oxidation (anammox), phylogenetic diversity, and distribution of anammox bacteria in sediments of four different marine aquaculture zones in Hong Kong (HK) were investigated. The 16S rRNA genes analysis indicated that sequences detected from Cheung Sha Wan (CSW) and Sok Kwu Wan (SKW) were closely related to several clusters within the Scalindua genus of anammox bacteria, including a new habitat-specific group, while only several sequences related to Scalindua and Kuenenia were detected in Sham Wan (SW) and Yim Tin Tsai East (YTTE). Most of the sequences obtained in SW and YTTE with the same PCR primers showed a low similarity to the known anammox bacteria, forming several novel groups within the Planctomycetes. However, results from the hydrazine oxidoreductase (HZO) encoding gene showed that only sequences from SW were related to the genus of Kuenenia, and sequences from other three sites were closely related to the genus of Scalindua. The community analysis showed that CSW and SKW share similar anammox bacterial community structures while SW and YTTE contain a unique anammox bacterial community. Furthermore, correlations reflect that organic matter is positively correlated with Kuenenia-like anammox bacteria, while the redox potential is significantly correlated with Scalindua-like anammox bacteria in marine aquaculture zones. Our results extend the knowledge of anammox bacteria in marine aquaculture systems and highlight the importance of environmental factors in shaping the community structures of anammox bacteria.

  20. Measuring System for Growth Control of the Spirulina Aquaculture

    Science.gov (United States)

    Ponce S., Claudio; Ponce L., Ernesto; Bernardo S., Barraza

    2008-11-01

    It describes the workings of a data-logging instrument that measures growth levels of the Spirulina aquaculture. The Spirulina is a very delicate algae and its culture may be suddenly lost due to overgrowth. This kind of instrument is not at present available in the market. The transduction is a submergible laser device whose measuring margin of error is near to 0.28%. The advantage of this new instrument is the improvement in the measurement and the low cost. The future application of this work is related to the industrial production of food and fuel from micro algae culture, for the growing world population.

  1. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept....... Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k0a) being equivalent for all twelve...

  2. 30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motor-starter enclosures; barriers and...-Voltage Distribution High-Voltage Longwalls § 75.819 Motor-starter enclosures; barriers and interlocks. Compartment separation and cover interlock switches for motor-starter enclosures must be maintained...

  3. Moisture ingress into electronics enclosures under isothermal conditions

    DEFF Research Database (Denmark)

    Staliulionis, Zygimantas; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

    2016-01-01

    loads are still not understood well by design engineers, therefore this field has become one of the bottlenecks in the electronics system design. The objective of this paper is to model moisture ingress into an electronics enclosure under isothermal conditions. The moisture diffusion model is based...

  4. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Science.gov (United States)

    2010-10-01

    ... published in “Rules for Building and Classing Steel Vessels”, 1981. (c) The steel cover for the aluminum... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  5. Containment Area Aquaculture Program. Economics and Marketing of Aquaculture in Dredged Material Containment Areas

    Science.gov (United States)

    1993-09-01

    history ............................ 26 Marketing the demonstration project shrimp .................. 27 Conclusions from Demonstration Project...let 4 U, aDl :5 S- - -- 41c- 06- I.’.*0 I" 1 -6 -2 01%- Chper3E~uto o w omN-nPjld2 Recent shrimp market history The CAAP demosttion project began in...Vicksburg, MS. Aquaculture Business Planning Hanson, J. S., Griffin, W. L., Klinefelter , D. A., and Fisher, D. V. (1988). "Developing an aquaculture

  6. Fluxes of greenhouse gases at two different aquaculture ponds in the coastal zone of southeastern China

    Science.gov (United States)

    Yang, Ping; He, Qinghua; Huang, Jiafang; Tong, Chuan

    2015-08-01

    Shallow water ponds are important contributors to greenhouse gas (GHG) fluxes into the atmosphere. Aquaculture ponds cover an extremely large area in China's entire coastal zone. Knowledge of greenhouse gas fluxes from aquaculture ponds is very limited, but measuring GHG fluxes from aquaculture ponds is fundamental for estimating their impact on global warming. This study investigated the magnitude of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes from two coastal aquaculture ponds during 2011 and 2012 in the Shanyutan wetland of the Min River estuary, southeastern China, and determined the factors that may regulate GHG fluxes from the two ponds. The average fluxes of CO2, CH4 and N2O were 20.78 mgCO2 m-2h-1, 19.95 mgCH4 m-2h-1 and 10.74 μgN2O m-2h-1, respectively, in the shrimp pond. The average fluxes of CO2, CH4 and N2O were -60.46 mgCO2 m-2h-1, 1.65 mgCH4 m-2h-1 and 11.8 μgN2O m-2h-1, respectively, in the mixed shrimp and fish aquaculture pond during the study period. The fluxes of all three gases showed distinct temporal variations. The variations in the GHG fluxes were influenced by interactions with the thermal regime, pH, trophic status and chlorophyll-a content. Significant differences in the CO2 and N2O fluxes between the shrimp pond and the mixed aquaculture pond were observed from September to November, whereas the CH4 fluxes from the two ponds were not significantly different. The difference in the CO2 flux likely was related to the effects of photosynthesis, biological respiration and the mineralization of organic matter, whereas the N2O fluxes were controlled by the interactions between nitrogen substrate availability and pH. Water salinity, trophic status and dissolved oxygen concentration likely affected CH4 emission. Our results suggest that subtropical coastal aquaculture ponds are important contributors to regional CH4 and N2O emissions into the atmosphere, and their contribution to global warming must be considered

  7. Aquaculture in Hawaii: Past, present, and future

    OpenAIRE

    Wyban, J; Wyban, C

    1989-01-01

    Hawaii's aquaculture industry has a long and colorful history. When Cook arrived in Hawaii in 1778, over 350 fishponds were in operation. Future prospects for Hawaii's industry are bright. Expanded R&D activities have the greatest growth potential with technology transfer through international consulting and training likely. Commercial activities will focus on intensive culture of shrimp, finfish and seaweeds.

  8. Can greening of aquaculture sequester blue carbon?

    Science.gov (United States)

    Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S

    2016-11-15

    Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.

  9. The use of probiotics in aquaculture.

    Science.gov (United States)

    Hai, N V

    2015-10-01

    This study aims to present comprehensive notes for the use of probiotics in aquaculture. Probiotics have been proven to be positive promoters of aquatic animal growth, survival and health. In aquaculture, intestines, gills, the skin mucus of aquatic animals, and habitats or even culture collections and commercial products, can be sources for acquiring appropriate probiotics, which have been identified as bacteria (Gram-positive and Gram-negative) and nonbacteria (bacteriophages, microalgae and yeasts). While a bacterium is a pathogen to one aquatic animal, it can bring benefits to another fish species; a screening process plays a significant role in making a probiotic species specific. The administration of probiotics varies from oral/water routine to feed additives, of which the latter is commonly used in aquaculture. Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms. Encapsulating probiotics with live feed is a suitable approach to convey probiotics to aquatic animals. Dosage and duration of time are significant factors in providing desired results. Several modes of actions of probiotics are presented, while some others are not fully understood. Suggestions for further studies on the effects of probiotics in aquaculture are proposed.

  10. Organic matter decomposition in simulated aquaculture ponds

    NARCIS (Netherlands)

    Torres Beristain, B.

    2005-01-01

    Different kinds of organic and inorganic compounds (e.g. formulated food, manures, fertilizers) are added to aquaculture ponds to increase fish production. However, a large part of these inputs are not utilized by the fish and are decomposed inside the pond. The microbiological decomposition of the

  11. Impact of selective breeding on European aquaculture

    NARCIS (Netherlands)

    Janssen, K.; Chavanne, H.; Berentsen, P.; Komen, H.

    2016-01-01

    Objectives of this study were to determine the combined market share of breeding companies in aquaculture production in Europe, to describe the main characteristics of breeding companies and their programs, and to provide per species estimates on cumulative genetic gain in growth performance. Sur

  12. THE STATUS OF AQUACULTURE IN THE WORLD AND IN EUROPE

    Directory of Open Access Journals (Sweden)

    Nikola Fijan

    2002-06-01

    Full Text Available During the past few years, several authors have presented the production data and the problems in Croatian aquaculture and suggested measures for improvements. Some of these authors referred to some sectors of aquaculture in the world. This paper reports basic statistical data of the Food and Agriculture Organization (FAO, United Nations of the world aquaculture during the period of 1990–1999. The annual growth rate in that period averaged about 10%, and in the year 1999 the aquaculture provided 31.7% of the world needs for aquatic products. The total production and industrialization of aquaculture will continue. Planning of aquaculture development in Croatia and the preparations for joining the European Economic Community must take into account the status of aquaculture and trends in the world, the common fishery policy of EEC (green document, the production in EEC member states and EEC–candidate states and especially the production in neighboring countries. The number, the size and the strength of organizational structures helping the development of aquaculture in EEC are showing these factors to be of decisive importance for the future of sustainable aquaculture in Croatia, too. The very low fish consumption in the country is a negative health factor for the Croatian citizens and it emphasizes the importance of faster development of aquaculture. The paper is intended to stimulate improvements in the aquaculture development strategy, to promote more positive approach towards this food production sector and to speed up its successfulness in Croatia.

  13. Sea-cage aquaculture, sea lice, and declines of wild fish.

    Science.gov (United States)

    Frazer, L Neil

    2009-06-01

    A sea cage, sometimes referred to as a net pen, is an enclosure designed to prevent farm fish from escaping and to protect them from large predators, while allowing a free flow of water through the cage to carry away waste. Farm fish thus share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes. Sea lice epidemics, together with recently documented population-level declines of wild salmon in areas of sea-cage farming, are a reminder that sea-cage aquaculture is fundamentally different from terrestrial animal culture. The difference is that sea cages protect farm fish from the usual pathogen-control mechanisms of nature, such as predators, but not from the pathogens themselves. A sea cage thus becomes an unintended pathogen factory. Basic physical theory explains why sea-cage aquaculture causes sea lice on sympatric wild fish to increase and why increased lice burdens cause wild fish to decline, with extirpation as a real possibility. Theory is important to this issue because slow declines of wild fish can be difficult to detect amid large fluctuations from other causes. The important theoretical concepts are equilibrium, host-density effect, reservoir-host effect, and critical stocking level of farmed fish (stocking level at which lice proliferate on farm fish even if wild fish are not present to infect them). I explored these concepts and their implications without mathematics through examples from salmon farming. I also considered whether the lice-control techniques used by sea-cage farmers (medication and shortened grow-out times) are capable of protecting wild fish. Elementary probability showed that W ≈ W* - εF (where W is the abundance of wild fish, W* is the prefarm abundance, F is the abundance of farm fish, and ε is the ratio of lice per farm fish to lice per wild fish). Declines of wild fish can be reduced by short growing cycles for farm fish, medicating farm fish, and keeping

  14. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy

    DEFF Research Database (Denmark)

    Hambly, Adam; Arvin, Erik; Pedersen, Lars-Flemming;

    2015-01-01

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs...... there was considerable variation between the five fluorescence components with respect to the degree of accumulation with feed loading. The five components were found to originate from three sources: the feed; the influent tap water (groundwater); and processes related to the fish and the water treatment system...

  15. Aquaculture effects on environmental and public welfare - the case of Mediterranean mariculture.

    Science.gov (United States)

    Grigorakis, K; Rigos, G

    2011-10-01

    Aquatic farming has been considered, during the last decades, as the fastest growing food production industry powered by governmental and technological impulsion. Compensation for fisheries decline, creation of new jobs and source of financial windfall are the most important benefits. However, similar to most of the human food-production activities, aquaculture raised several issues related to the environmental welfare and consumer safety. An effort to record the aquaculture-environment and -human safety interactions with regard to the Mediterranean mariculture, is attempted herein. We focused on this geographical area due to its individualities in both the hydrological and physicochemical characteristics and the forms of aquaculture activities. The cage farming of euryhaline marine fish species and more recently of bluefin tuna and mollusk farming are the dominating aquaculture activities. The impacts of these activities to the environment, through wastes offloads, introduction of alien species, genetic interactions, disease transfer, release of chemicals, use of wild recourses, alterations of coastal habitats and disturbance of wildlife, are analytically considered. Also the consumer safety issues related to the farming are assessed, including generation of antibiotic-resistant microorganisms, contaminants transferred to humans though food chain and other hazards from consumption of aquacultured items. Within these, the major literature findings are critically examined and suggestions for scientific areas that need further development are made. The major tasks for future aquaculture development in this region are: (i) to ensure sustainability and (ii) to balance the risks to public or environmental health with the substantial economical benefits. In regard with monitoring, tools must be created or adapted to predict the environmental costs and estimate consumer impact. At a canonistic and legal basis, the establishment of appropriate legal guidelines and common

  16. Using Metadata Description for Agriculture and Aquaculture Papers

    Directory of Open Access Journals (Sweden)

    P. Šimek, J. Vaněk, V. Očenášek, M. Stočes, T. Vogeltanzova

    2012-12-01

    Full Text Available The paper deals with the most used metadata formats and thesauri suitable for describing scientific and research papers in the domains agriculture, food industry, aquaculture, environment and rural areas. These include the Dublin Core (DC, Metadata Object Description Schema (MODS, Virtual Open Access Agriculture and Aquaculture Repository Metadata Application Profile (VOA3R AP and the AGROVOC thesaurus. Having analyzed the metadata formats and research paper lifecycle, the authors would recommend that each paper should entail metadata description as soon as it is published. The metadata are to describe the content and properties of the paper. One of the most suitable metadata formats is the VOA3R AP that is partially patterned on the DC and combined with the AGROVOC thesaurus. As a result, an effective description, availability and automatic data exchange between and among local and central repositories should be attained.The knowledge and data presented in the present paper were obtained as a result of the following research programs and grant schemes: the Grant No. 20121044 of the Internal Grant Agency titled „Using Automatic Metadata Generation for Research Papers“, the Grant agreement No. 250525 funded by the European Commission corresponding to the VOA3R Project (Virtual Open Access Agriculture & Aquaculture Repository: Sharing Scientific and Scholarly Research related to Agriculture, Food, and Environment, http://voa3r.eu and the Research Program titled „Economy of the Czech Agriculture Resources and their Efficient Use within the Framework of the Multifunctional Agrifood Systems“ of the Czech Ministry of Education, Youth and Sport number VZ MSM 6046070906.

  17. [Evaluation of cultural service value of aquaculture pond ecosystem: a case study in a water conservation area of Shanghai].

    Science.gov (United States)

    Li, Sheng; Guo, Zong-xiang; Yang, Huai-yu; Yang, Zheng-yong

    2009-12-01

    Pond aquaculture has existed in China for thousands of years, which has not only contributed great economic value, but also presented cultural value for human beings. With the development and upgrading of Chinese economy and culture, these values will be highlighted further. To evaluate the cultural service value of pond aquaculture ecosystem would provide a scientific base to the policy-making to avoid or reduce the wrong design-making or avoid the policy-malfunction, and also, to promote the development of aquaculture and related recreational fishing industry, increase the added value of aquaculture and the income of fish-farmers, and promote the economic development of rural area. Based on the survey data from the aquaculture ponds in the water conservation area of Dianshan Lake in Qingpu District of Shanghai and the related statistical data, the cultural service value including recreational value and existence value of the aquaculture pond ecosystem in the area was estimated by means of travel cost method (TCM) and contingent valuation method (CVM). The total cultural service value of this ecosystem was about 213 million Yuan x a(-1) or 231296. 69 Yuan x hm(-2) x a(-1), being 5. 25 times of the market value of aquaculture products, among which, recreational value was about 189 million Yuan x a(-1), and existence value was about 24 million Yuan x a(-1). It was suggested that in the construction of new rural areas of Shanghai, sufficient attention should be paid on the full play of the cultural service value of aquaculture pond ecosystem.

  18. [Preliminary studies on the occurrence of antibiotic resistance genes in typical aquaculture area of the Pearl River Estuary].

    Science.gov (United States)

    Liang, Xi-Mei; Nie, Xiang-Ping; Shi, Zhen

    2013-10-01

    Traditional and quantitative PCR techniques were used to determine the occurrence and quantities of ARGs, including three types of genes resistant to sulfonamide, seven for tetracycline resistance and one for quinolone resistance, as well as one integron gene in typical aquaculture of the Pearl River Estuary. The results showed that all genes except for tetW were detectable in the aquaculture environment, and sull, sul2 and int1 were the most frequently detected genes (detectable percentage, 100% ). Relative abundances of ARGs increased with the prolongation of rearing time under the same aquaculture pattern, suggesting a cumulative effect. Moreover, the occurrences of ARGs in the ponds were different with different aquaculture patterns, indicating that the aquaculture pattern might play an important role in the abundances and distributions of ARGs. Relative abundances of intl, as a horizontal mobile genetic element, were significantly correlated to the levels of sull and the total ARGs (P aquaculture substantially increased the abundances of ARGs probably owning to the induction of horizontal gene transfer of ARGs among bacteria.

  19. Beta-glucan: an ideal immunostimulant in aquaculture (a review).

    Science.gov (United States)

    Meena, D K; Das, Pronob; Kumar, Shailesh; Mandal, S C; Prusty, A K; Singh, S K; Akhtar, M S; Behera, B K; Kumar, Kundan; Pal, A K; Mukherjee, S C

    2013-06-01

    The major hindrance in the development and sustainability of aquaculture industry is the occurrence of various diseases in the farming systems. Today, preventive and management measures are central concern to overcome such outbreak of diseases. Immunostimulants are considered as an effective tool for enhancing immune status of cultured organisms. Among different immunostimulants used in aquaculture practices, β-glucan is one of the promising immunostimulant, which is a homopolysaccharide of glucose molecule linked by the glycoside bond. It forms the major constituents of cell wall of some plants, fungi, bacteria, mushroom, yeast, and seaweeds. Major attention on β-glucan was captivated with the gain in knowledge on its receptors and the mechanism of action. The receptor present inside the animal body recognizes and binds to β-glucan, which in turn renders the animal with high resistance and enhanced immune response. This review highlights β-glucan as an immunostimulant, its effective dosages, and route of administration and furthermore provides an outline on role of β-glucan in enhancing growth, survival, and protection against infectious pathogens pertaining to fishes and shellfishes. Study also summarizes the effect of β-glucan on its receptors, recognition of proteins, immune-related enzymes, immune-related gene expression and their mechanisms of action.

  20. Development of a European resource on the origins of pathogens of aquaculture: The Europa Project

    DEFF Research Database (Denmark)

    Snow, M.; Barja, J.; Colquhoun, D.;

    2004-01-01

    This workshop described the EUROPA project, an EU-funded program aimed at creating a web-based database of molecular sequence data-sets related to significant pathogens of aquaculture. The project aims to focus the efforts of fish health researchers into generating large, evolving and readily ava...

  1. A Needs Assessment of Aquaculture Extension Agents, Specialists, and Program Administrators in Extension Programming

    Science.gov (United States)

    Schwarz, Michael H.; Gibson, Jerry

    2010-01-01

    The study reported here identified continuing education and training needs of aquaculture Extension agents, specialists, and program administrators in 10 competency areas relating to the need for continuing education or training. Fourteen resources on the AquaNIC Web site were also evaluated, as was the efficacy of the AQUA-EXT listserv. Data were…

  2. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2014-01-01

    The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation to ...

  3. ZONING OF COASTAL AREA FOR MARINE AQUACULTURE Š PRESENT SITUATIONS AND PROBLEMS

    Directory of Open Access Journals (Sweden)

    Lav Bavčević

    2001-12-01

    Full Text Available We already acepted that Croatian economical and geopolitical possition can bee improved only with better utilization of coastal area. Under these conditions mariculture also makes a part od sea master plan because demands for mariculture are focused on clean environmental conditions to obtain economic benefits. Increased pressure to the coastal area is global trend and if not planed and organized can provoke conflicts and can affect further development. Under these condition, marine aquaculture is frequent subject of many discussion focused on the environmental impact. Conflict of different interest in coastal area with no argumentation is putting marine aquaculture in worst position related with tourism and industry. Hard argumentations is laying in noneadequate frame of work in some facilities and to take advantake competitors are preasenting marine aquaculture in worst picture. Marine aquaculture product has to be health product, which can be completely damaged because of non-responsible approach of other activity. Mariculture also can suffer from self-pollution as for example tourism and must be well planed and managed. Fecal pollution from towns, pollution from bad controlled tourists activity, industry, influence of intensive and non controlled agriculture in coast line, are also potential danger for quality of all sea products and also cultured products from marine aquaculture. High quality of marine products can be obtained by zoning of coastal area, and in concept of these zoning it is necessary to define the zones for marine aquaculture. Procedure of zoning has to be divided in three steps: deetrmination of present status of area, definition of shore land for making mariculture related shore infrastructure and definitions of areas suitable for mariculture with limits of production. These can make positive situations with avoiding conflicts in exploitation of common resources in future. Zone for marine aquaculture has to be controlled

  4. Innovative enclosure dome/observing aperture system design for the MROI Array Telescopes

    Science.gov (United States)

    Busatta, A.; Marchiori, G.; Mian, S.; Payne, I.; Pozzobon, M.

    2010-07-01

    The close-pack array of the MROI necessitated an original design for the Unit Telescope Enclosure (UTE) at Magdalena Ridge Observatory. The Magdalena Ridge Observatory Interferometer (MROI) is a project which comprises an array of up to ten (10) 1.4m diameter mirror telescopes arranged in a "Y" configuration. Each of these telescopes will be housed inside a Unit Telescope Enclosure (UTE) which are relocatable onto any of 28 stations. The most compact configuration includes all ten telescopes, several of which are at a relative distance of less than 8m center to center from each other. Since the minimum angle of the field of regard is 30° with respect to the horizon, it is difficult to prevent optical blockage caused by adjacent UTEs in this compact array. This paper presents the design constraints inherent in meeting the requirement for the close-pack array. An innovative design enclosure was created which incorporates an unique dome/observing aperture system. The description of this system focuses on how the field of regard requirement led to an unique and highly innovative concept that had to be able to operate in the harsh environmental conditions encountered at an altitude of 10,460ft (3,188m). Finally, we describe the wide use of composites materials and structures (e.g. glass/carbon fibres, sandwich panels etc.) on the aperture system which represents the only way to guarantee adequate thermal and environmental protection, compactness, structural stability and limited power consumption due to reduced mass.

  5. In plant partial noise enclosures for the mining industry

    Energy Technology Data Exchange (ETDEWEB)

    Kinevy, P.T.

    1993-10-01

    The Physical and Toxic Agents Division of the Mine Safety and Health Administration`s Pittsburgh Safety and Health Technology Center has conducted three joint noise control demonstrations at dry milling operations. These demonstrations were conducted on a rod mill, a roller mill, and a ball mill, in order to survey a representative sample of the more commonly utilized types of milling equipment. The noise control concept that was demonstrated involved the construction of partial enclosures surrounding the mills and then adding acoustical materials within the enclosures to absorb the build up of acoustical energy. The results of this work illustrate the feasibility of this concept, the physical principle of creating an acoustical shadow, and the ability to closely predict the amount of absorptive material required to reduce the noise levels so as to comply with the Code of Federal Regulations (CFR), Title 30.

  6. Enclosure for small animals during awake animal imaging

    Science.gov (United States)

    Goddard, Jr., James S

    2013-11-26

    An enclosure or burrow restrains an awake animal during an imaging procedure. A tubular body, made from a radiolucent material that does not attenuate x-rays or gamma rays, accepts an awake animal. A proximal end of the body includes an attachment surface that corresponds to an attachment surface of an optically transparent and optically uniform window. An anti-reflective coating may be applied to an inner surface, an outer surface, or both surfaces of the window. Since the window is a separate element of the enclosure and it is not integrally formed as part of the body, it can be made with optically uniform thickness properties for improved motion tracking of markers on the animal with a camera during the imaging procedure. The motion tracking information is then used to compensate for animal movement in the image.

  7. Characteristics of Electromagnetic Coupling with A Wire through Shielding Enclosure

    Directory of Open Access Journals (Sweden)

    Yanpeng Sun

    2013-09-01

    Full Text Available The paper presents a numerical method based on Finite Difference Time Domain (FDTD in both frequency and time domain for modeling the coupling of an incident electromagnetic pulse(EMP with a conducting wire through a metallic shielding enclosure with a small aperture. Simulation and analysis are done by radius, length, and number of the wires, the incidence angle of EMP and the polaration angle of electric field in consideration. The simulation result shows that interference of the electromagnetic coupling into the shielding enclosure can be affected in different degrees by above factors. At low frequency, the larger the leakage length, the radius or the number of the wire penetrated into the cavity, the more interference is coupled into the shielding cavity from electromagnetic field. Also, the smaller the incident direction angle of propagation of the electromagnetic pulse or the polarization direction angle of the incident electric field, the more easily the electromagnetic interference is coupled into the cavity.

  8. Carotenoids in Aquaculture: Fish and Crustaceans

    Science.gov (United States)

    Bjerkeng, Bjorn

    This Chapter deals with selected topics on the use of carotenoids for colouration in aquaculture and incudes examples from ecological studies which support our understanding of functions and actions of carotenoids and colouration in fishes and crustaceans. Animal colours may be physical or structural in origin [1], e.g. Tyndall blues and iridescent diffraction colours, or they may be due to pigments, including carotenoids (Chapter 10).

  9. Probiotics as Control Agents in Aquaculture

    Institute of Scientific and Technical Information of China (English)

    Gómez R. Geovanny D; Balcázar José Luis; MA Shen

    2007-01-01

    Infectious diseases constitute a limiting factor in the development of the aquaculture production, and control has solely concentrated on the use of antibiotics. However, the massive use of antibiotics for the control of diseases has been questioned by acquisition of antibiotic resistance and the need of alternative is of prime importance. Probiotics, live microorganisms administered in adequate amounts that confer a healthy effect on the host, are emerging as significant microbial food supplements in the field of prophylaxis.

  10. New aquaculture drugs under FDA review

    Science.gov (United States)

    Bowker, James D.; Gaikowski, Mark P.

    2012-01-01

    Only eight active pharmaceutical ingredients available in 18 drug products have been approved by the U.S. Food and Drug Administration for use in aquaculture. The approval process can be lengthy and expensive, but several new drugs and label claims are under review. Progress has been made on approvals for Halamid (chloramine-T), Aquaflor (florfenicol) and 35% PeroxAid (hydrogen peroxide) as therapeutic drugs. Data are also being generated for AQUI-S 20E, a fish sedative.

  11. Probiotics as control agents in aquaculture

    Science.gov (United States)

    Geovanny D, Gómez R.; Balcázar, José Luis; Ma, Shen

    2007-01-01

    Infectious diseases constitute a limiting factor in the development of the aquaculture production, and control has solely concentrated on the use of antibiotics. However, the massive use of antibiotics for the control of diseases has been questioned by acquisition of antibiotic resistance and the need of alternative is of prime importance. Probiotics, live microorganisms administered in adequate amounts that confer a healthy effect on the host, are emerging as significant microbial food supplements in the field of prophylaxis.

  12. Probiotics as Antiviral Agents in Shrimp Aquaculture

    OpenAIRE

    Bestha Lakshmi; Buddolla Viswanath; Sai Gopal, D. V. R.

    2013-01-01

    Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are ch...

  13. Acoustic control in enclosures using optimally designed Helmholtz resonators

    Science.gov (United States)

    Driesch, Patricia Lynne

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, acoustic absorbers (Helmholtz resonators). A series expansion of eigen functions is used to represent the acoustic absorbers as external volume velocities, eliminating the need for a solution of large matrix eigen value problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a benchmarking exercise, this novel methodology was experimentally validated for a narrowband acoustic assessment of two optimally designed Helmholtz resonators coupled to a 2D enclosure. The resonators were tuned to the two lowest resonance frequencies of a 30.5 by 40.6 by 2.5 cm (12 x 16 x 1 inch) cavity with the resonator volume occupying only 2% of the enclosure volume. A maximum potential energy reduction of 12.4 dB was obtained at the second resonance of the cavity. As a full-scale demonstration of the efficacy of the proposed design method, the acoustic response from 90--190 Hz of a John Deere 7000 Ten series tractor cabin was investigated. The lowest cabin mode, referred to as a "boom" mode, proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound pressure levels. Exploiting the low frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators; potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  14. Risks of Using Antifouling Biocides in Aquaculture

    Directory of Open Access Journals (Sweden)

    José Meseguer

    2012-02-01

    Full Text Available Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT. The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211®, Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine, zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms.

  15. Risks of using antifouling biocides in aquaculture.

    Science.gov (United States)

    Guardiola, Francisco Antonio; Cuesta, Alberto; Meseguer, José; Esteban, Maria Angeles

    2012-01-01

    Biocides are chemical substances that can deter or kill the microorganisms responsible for biofouling. The rapid expansion of the aquaculture industry is having a significant impact on the marine ecosystems. As the industry expands, it requires the use of more drugs, disinfectants and antifoulant compounds (biocides) to eliminate the microorganisms in the aquaculture facilities. The use of biocides in the aquatic environment, however, has proved to be harmful as it has toxic effects on the marine environment. Organic booster biocides were recently introduced as alternatives to the organotin compounds found in antifouling products after restrictions were imposed on the use of tributyltin (TBT). The replacement products are generally based on copper metal oxides and organic biocides. The biocides that are most commonly used in antifouling paints include chlorothalonil, dichlofluanid, DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, Sea-nine 211(®)), Diuron, Irgarol 1051, TCMS pyridine (2,3,3,6-tetrachloro-4-methylsulfonyl pyridine), zinc pyrithione and Zineb. There are two types of risks associated with the use of biocides in aquaculture: (i) predators and humans may ingest the fish and shellfish that have accumulated in these contaminants and (ii) the development of antibiotic resistance in bacteria. This paper provides an overview of the effects of antifouling (AF) biocides on aquatic organisms. It also provides some insights into the effects and risks of these compounds on non-target organisms.

  16. Probiotics as Antiviral Agents in Shrimp Aquaculture

    Directory of Open Access Journals (Sweden)

    Bestha Lakshmi

    2013-01-01

    Full Text Available Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

  17. Probiotics as antiviral agents in shrimp aquaculture.

    Science.gov (United States)

    Lakshmi, Bestha; Viswanath, Buddolla; Sai Gopal, D V R

    2013-01-01

    Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

  18. Meeting the Needs for More Fish Through Aquaculture

    Science.gov (United States)

    Giap, D. H.; Lam, T. J.

    2015-10-01

    Fish is one of the major sources of animal protein. Due to rising world populations, increasing income and urbanization, demand for fish has been increasing. In order to meet the need for more fish, aquaculture has become increasingly important as wild populations and production from capture fisheries have declined due to overfishing and poor management. In recent years, production from aquaculture has increased rapidly to address the shortfalls in capture fisheries, especially in Asia where aquaculture production accounts for about 90% of world aquaculture production by volume. This paper reviews the status of the world’s fish production, provides an update on Asian aquaculture, and highlights developments that are contributing to sustainable fish production, particularly integrated multi-trophic aquaculture and aquaponics.

  19. Effects of Power Lines on Area Use and Behaviour of Semi-Domestic Reindeer in Enclosures

    Directory of Open Access Journals (Sweden)

    K. Flydal

    2009-01-01

    Full Text Available We conducted large-scale, replicated experiments to test the effects of two parallel power lines on area use, behaviour, and activity of semidomestic reindeer in enclosures. Yearling female reindeer were released into four 50×400 m enclosures; two treatment enclosures with power lines and two control enclosures. Reindeer from two herds, one from Kautokeino (domestic tame and one from Vågå, (domestic wild were tested separately and compared. Individual location within the enclosures was not affected by the power lines. Effects on restless behaviour were ambiguous, with slightly more restless behaviour in the treatment enclosures for the domestic tame reindeer, while the domestic wild reindeer maintained a stable level in the treatment enclosures, increasing with time in the control enclosures. Activity changes were slightly more common among animals within treatment enclosures for both herds, with no indication of habituation during the experiment. The domestic wild reindeer had more than three times the amount of restless behaviour than the domestic tame reindeer. Our study indicates that for reindeer in enclosures, the disturbance from a power line construction is negligible. This suggests that power lines are a minor disturbing factor compared to human handling when using fenced in areas like grazing gardens in reindeer husbandry.

  20. Osnovy formirovanija sistemy upravlenija riskami proektov innovacionnogo razvitija akvakul'tury v regione (Na primere Kaliningradskoj oblasti [The formation of a risk management system for projects in the field of aquaculture innovative development in the Kaliningrad region: a case study

    Directory of Open Access Journals (Sweden)

    Serbulov Alexey

    2012-01-01

    Full Text Available This article sets out to develop the concept and the principal scheme of the formation of a risk management system for innovative economic development projects in the field of aquaculture. The research carried out by the authors helps identify the main problems and characteristics of risk management projects for the development of aquaculture in presentday Russia. The authors outline the status and features of aquaculture development projects in the North-western federal district and the Kaliningrad region. The article formulates and justifies the concept of “risk management projects in innovative development of aquaculture in the region” focusing on the classification of aquaculture risks in relation to innovative development projects, which expands the conceptual framework of risk management in view of the specific risks relating to economic development projects in the field of aquaculture. The authors characterize modern methods and approaches to risk management projects and organizations in the context of their application in the framework of aquaculture development projects and offer mechanisms for risk management of aquaculture development projects, which make it possible to include risk management activity in the general context of activities of parent project organizations. The authors develop the concept and principal scheme of the formation of risk management system for innovative development projects in aquaculture.

  1. What shapes food value chains? Lessons from aquaculture in Asia

    DEFF Research Database (Denmark)

    Jespersen, Karen Sau; Kelling, I; Ponte, Stefano

    2014-01-01

    In this article, we explain what shapes food value chains through the analysis of selected aquaculture industries in four key Asian producing countries. Worldwide production of aquatic resources has grown rapidly in the past few decades, and aquaculture production in Asia has played a decisive role...... and private standards. We find that the most sophisticated aquaculture operations in Asia are found in value chains led by retailers and branded processors and where the quality of domestic institutional frameworks has facilitated compliance with increasing demands from buyers overseas. Finally, we reflect...... on the sustainability challenges of aquaculture and provide four broad observations on the governance of food value chains....

  2. Building Enclosure Hygrothermal Performance Study, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2002-08-08

    The moisture performance of three different classes of wall systems has been investigated in the context of the preliminary hygrothermal analysis of walls in Seattle. The results reported in this phase specifically address the moisture performance of walls designed with loads that have some unintentional water penetration. The results have been developed in a manner to present the relative performance of the walls in the same climate with similar water penetration effects. The analysis was performed with the best available input data. Several limitations should be recognized within the context of this study. Results showed that selection of wooden sheathing boards on interior vapor-tight assemblies does not significantly influence the performance of stucco-clad walls. A larger effect was observed when the interior vapor control is made vapor open. When continuous cavity ventilation is employed, the effect of the selection of the type of sheathing board on the hygrothermal performance of the wall was found to be negligible. When comparing oriented strand board sheathing performance against the performance of exterior grade gypsum, the differences are very significant in terms of the amount of moisture content present in the walls. Moisture content alone does not indicate their respective durability as durability is directly related to the combination of relative humidity and temperature, mechanical, chemical, and biological properties of the substrates. This study did not investigate the durability performance of either sheathing. In terms of interior vapor control, inhabitant behavior must be considered during the wall hygrothermal design stage. If interior relative humidity is maintained below 60%, then a latex primer and paint may perform better than the use of PVA or even a polyethylene sheet. When the interior environment is maintained at a higher relative humidity, then stricter vapor control is needed. Multilayered building paper was experimentally shown to

  3. A Place Along the Way: Contextualising Findings from the Iron Age Post Enclosure at Lismullin, Co. Meath, Ireland

    Science.gov (United States)

    Prendergast, Frank

    2015-05-01

    The discovery of an Early Iron Age timber-built post enclosure at Lismullin is arguably the most significant Irish archaeological discovery in recent times. When found, it was immediately evident that a site of major importance and cultural significance had been located. The enclosure complex was constructed from a large number of small wooden posts set out in the form of a three ring structure with an easterly facing avenue accentuated by a four-post entrance feature. This paper summarises the analysis of the geospatial data obtained at the site, and addresses three lines of enquiry relating to the construction method and structural orientation. The cultural significance of the discovery and the findings arising from the data analysis are considered.

  4. Numerical study of natural convection characteristics of nanofluids in an enclosure using multiphase model

    Science.gov (United States)

    Chen, Yan-Jun; Wang, Ping-Yang; Liu, Zhen-Hua

    2016-11-01

    The natural convective heat transfer and flow characteristics of nanofluids in an enclosure are numerically simulated using the multiphase-flow model and single phase model respectively. The simulated results are compared with the experimental results from the published papers to investigate the applicability of these models for nanofluids from a macro standpoint. The effects of Rayleigh number, Grashof number and volume concentration of nanoparticles on the heat transfer and flow characteristics are investigated and discussed. Comparisons of the horizontal and vertical central dimensionless velocity profiles between nanofluid and water for various Grashof numbers are studied. In addition, both streamline contours and isotherms lines for different volume concentrations of nanofluids are analyzed as well. The study results show that a great deviation exists between the simulated result of the single phase model and the experimental data on the relation of Nusselt number and Rayleigh number, which indicates that the single phase model cannot reflect the heat transfer characteristic of nanofluid. While the simulated results using the multiphase-flow model show a good agreement with the experimental data of nanofluid, which means that the multiphase-flow model is more suitable for the numerical study of nanofluid. For the natural convection, the present study holds the point that using Grashof numbers as the benchmark would be more appropriate to describe the heat transfer characteristics of nanofluid. Moreover, the simulated results demonstrate that adding nanoparticles into the base fluid can enhance both the motion of fluid and convection in the enclosure significantly.

  5. Assessing the benefits of design for recycling for plastics inelectronics: A case study of computer enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Masanet, Eric; Horvath, Arpad

    2007-12-31

    With the emergence of extended producer responsibilityregulations for electronic devices, it is becoming increasingly importantfor electronics manufacturers to apply design for recycling (DFR) methodsin the design of plastic enclosures. This paper presents an analyticalframework for quantifying the environmental and economic benefits of DFRfor plastic computer enclosures during the design process, usingstraightforward metrics that can be aligned with corporate environmentaland financial performance goals. The analytical framework is demonstratedvia a case study of a generic desktop computer enclosure design, which isrecycled using a typical US "take-back" system for plastics from wasteelectronics. The case study illustrates how the analytical framework canbe used by the enclosure designer to quantify the environmental andeconomic benefits of two important DFR strategies: choosing high-valueresins and minimizing enclosure disassembly time. Uncertainty analysis isperformed to quantify the uncertainty surrounding economic conditions inthe future when the enclosure is ultimately recycled.

  6. Design, construction and testing of a DC bioeffects test enclosure for small animals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, M J; Preache, M M

    1980-11-01

    This final report describes both the engineering development of a DC bioeffects test enclosure for small laboratory animals, and the biological protocol for the use of such enclosures in the testing of animals to determine possible biological effects of the environment associated with HVDC transmission lines. The test enclosure which has been designed is a modular unit, which will house up to eight rat-sized animals in individual compartments. Multiple test enclosures can be used to test larger numbers of animals. A prototype test enclosure has been fabricated and tested to characterize its electrical performance characteristics. The test enclosure provides a simulation of the dominant environment associated with HVDC transmission lines; namely, a static electric field and an ion current density. A biological experimental design has been developed for assessing the effects of the dominant components of the HVDC transmission line environment.

  7. Proteomics and its applications to aquaculture in China: infection, immunity, and interaction of aquaculture hosts with pathogens.

    Science.gov (United States)

    Peng, Xuan-Xian

    2013-01-01

    China is the largest fishery producer worldwide in term of its aquaculture output, and plays leading and decisive roles in international aquaculture development. To improve aquaculture output further and promote aquaculture business development, infectious diseases and immunity of fishes and other aquaculture species must be studied. In this regard, aquaculture proteomics has been widely carried out in China to get a better understanding of aquaculture host immunity and microbial pathogenesis as well as host-pathogen interactions, and to identify novel disease targets and vaccine candidates for therapeutic interventions. These proteomics studies include development of novel methods, assays, and advanced concepts in order to characterize proteomics mechanisms of host innate immune defense and microbial pathogenesis. This review article summarizes some recently published technical approaches and their applications to aquaculture proteomics with an emphasis on the responses of aquaculture animals to bacteria, viruses, and other aqua-environmental stresses, and development of broadly cross-protective vaccine candidates. The reviewed articles are those that have been published in international peer reviewed journals.

  8. DNA vaccines for aquacultured fish

    DEFF Research Database (Denmark)

    Lorenzen, Niels; LaPatra, S.E.

    2005-01-01

    in various animal species as well as in humans, the vaccines against rhabdovirus diseases in fish have given some of the most promising results. A single intramuscular (IM) injection of microgram amounts of DNA induces rapid and long-lasting protection in farmed salmonids against economically important...... viruses such as infectious haematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV). DNA vaccines against other types of fish pathogens, however, have so far had limited success. The most efficient delivery route at present is IM injection, and suitable delivery strategies...... for mass vaccination of small fish have yet to be developed. In terms of safety, no adverse effects in the vaccinated fish have been observed to date. As DNA vaccination is a relatively new technology, various theoretical and long-term safety issues related to the environment and the consumer remain...

  9. Determination of melamine in aquaculture feed samples based on molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Lian, Ziru; Liang, Zhenlin; Wang, Jiangtao

    2015-10-01

    This research highlights the application of highly efficient molecularly imprinted solid-phase extraction for the preconcentration and analysis of melamine in aquaculture feed samples. Melamine-imprinted polymers were synthesized employing methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker, respectively. The characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted polymers showed an excellent adsorption ability for melamine and were applied as special solid-phase extraction sorbents for the selective cleanup of melamine. An off-line molecularly imprinted solid-phase extraction procedure was developed for the separation and enrichment of melamine from aquaculture feed samples prior to high-performance liquid chromatography analysis. Optimum molecularly imprinted solid-phase extraction conditions led to recoveries of the target in spiked feed samples in the range 84.6-96.6% and the relative standard deviation less than 3.38% (n = 3). The aquaculture feed sample was determined, and there was no melamine found. The results showed that the molecularly imprinted solid-phase extraction protocols permitted the sensitive, uncomplicated and inexpensive separation and pre-treatment of melamine in aquaculture feed samples.

  10. The Importance of Supratidal Habitats for Wintering Shorebirds and the Potential Impacts of Shrimp Aquaculture

    Science.gov (United States)

    Yasué, M.; Dearden, P.

    2009-06-01

    Intensive black tiger shrimp ( Penaeus monodon) aquaculture ponds have replaced significant areas of coastal wetlands throughout tropical Asia. Few studies have assessed potential impacts on avian foraging habitats. At Khao Sam Roi Yod National Park, Thailand, seminatural wetlands have been converted to either shrimp ponds or to salinization ponds that provide saline water for shrimp aquaculture. Although shorebirds cannot feed in aquaculture ponds, hypersaline ponds can provide productive foraging areas. Thus, the overall impact of the shrimp industry on shorebirds depends partly on the relative quality of the salt ponds compared to seminatural wetlands. In this study, we examined wintering shorebird use of tidal ( N = 5 sites) and supratidal areas (four wetland sites, four salt pond sites) and compared the shorebird community (14 species), prey availability, profitability, and disturbance rates between wetlands and salt ponds. Two shorebird species fed in higher densities in wetlands, whereas seven species were more abundant in salt ponds. Large juvenile fish and dragonfly larvae were more abundant in wetlands, whereas there were more small Chironomid midge and fly larvae in salt ponds. We conclude that salt ponds might provide higher-quality foraging habitats compared to wetlands for small shorebirds species because of the abundance of small larvae. However, the shrimp aquaculture industry reduces habitat availability for shorebirds feeding on larger prey. This study demonstrates a comprehensive, multispecies approach to assess the impacts of a large-scale change in coastal habitats for wintering shorebirds.

  11. Questing ixodid ticks on the vegetation of sable antelope and multi-herbivore enclosures in Thabazimbi

    Directory of Open Access Journals (Sweden)

    André C. Uys

    2015-03-01

    Full Text Available This survey of ixodid ticks was the first to compare the species composition and population dynamics of free-living ticks in intensive, sable antelope breeding enclosures, now commonplace in commercial wildlife ranching in South Africa, with those of multi-herbivore enclosures. The species composition, abundance and seasonal abundance of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelope (Hippotragus niger, on which strategic tick control is practised, were compared with those of ticks in a multi-species herbivore enclosure surrounding the breeding enclosures in which no tick control is practised. A total of eight ixodid tick species were collected by drag-sampling the woodland and grassland habitats in each enclosure type monthly from July 2011 to July 2013. Rhipicephalus decoloratus, a potential vector of fatal tick-borne disease in sable antelopes, was the most abundant, accounting for 65.4% of the total number of ticks collected in the sable enclosures, whilst representing only 25.4% of number of ticks collected in the multi-species herbivore enclosure. Rhipicephalus decoloratus and R. evertsi evertsi were more abundant than R. appendiculatus (both p < 0.05 and Amblyomma hebraeum (p < 0.001 and p < 0.01, respectively. Rhipicephalus decoloratus larvae were collected throughout the year, with peak collections in November 2012 and October to December 2013 in the sable enclosures; and in April/May 2012 and February/April 2013 in the multi-species herbivore enclosure. More R. decoloratus were recovered in the second year than in the first year in the grassland habitat of the sable enclosures (V = 7.0, p < 0.05 possibly as a result of acaricide resistance. The apparent temporal over-abundance of R. decoloratus in sable antelope breeding enclosures, in the face of strategic tick control, is of concern and requires further investigation.

  12. Privacy, Exploitation, and the Digital Enclosure

    Directory of Open Access Journals (Sweden)

    Marc Andrejevic

    2009-08-01

    Full Text Available

    Approaches to the regulation of commercial information collection in the digital era tend to ground themselves on notions of privacy and consumer choice. This essay proposes a supplementary approach that considers the generation of personal information to be a value – generating activity analogous in important respects to productive labour. It argues that regulatory regimes need to take into consideration the power relations that structure the terms of access to commercial information and communication resources. In an economy wherein the boundaries between work and other spheres of social life continue to blur, access to such resources is not merely a consumer convenience, but an increasingly important workplace asset.

  13. Perception of Aquaculture Education to Support Further Growth of Aquaculture Industry in Victoria, Australia

    Science.gov (United States)

    Awal, Sadiqul; Christie, Andrew; Watson, Matthew; Hannadige, Asanka G. T.

    2012-01-01

    Purpose: The central aim of this study was to determine the perception of aquaculture educational provisions in the state of Victoria, and whether they are sufficient to ultimately support further growth of the industry. Design/methodology/approach: Questionnaires were formulated and distributed to participants in a variety of ways, including via…

  14. Development of a General Method for Determining Leak Rates from Limiting Enclosures

    Science.gov (United States)

    Zografos, A. I.; Blackwell, C. C.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a general method for the determination of very low leak rates from limiting enclosures. There are many methods that can be used to detect and repair leaks from enclosures. Many methods have also been proposed that allow the estimation of actual leak rates, usually expressed as enclosure volume turnover. The proposed method combines measurements of the state variables (pressure, temperature, and volume) as well as the change in the concentration of a tracer gas to estimate the leak rate. The method was applied to the containment enclosure of the Engineering Development Unit of the CELSS Test Facility, currently undergoing testing at the NASA Ames Research Center.

  15. A survey of enclosure suspension and rotation systems for 3-15m telescopes

    Science.gov (United States)

    Bigelow, Bruce C.; Loewen, Nathan P.; van Vuuren, Emile; Burgett, William S.

    2016-07-01

    The suspension and rotation systems (typically called bogies) for Extremely Large Telescope (ELT) enclosures will carry structures that are 2-3 times greater in diameter and much heavier than enclosures for the previous generation of 6-10m telescopes. Via on-site visits and/or engineering documentation, we have surveyed eleven optical, infrared, and submillimeter 3-15m telescope enclosures, and report on key design features of the suspension and rotation systems, including wheel and track geometry, the wheel/track interface, average load per wheel, rotation drive method, etc. We discuss key considerations for the development of future suspension and rotation systems for ELT enclosures.

  16. Offshore finfish aquaculture in the United States: An examination of federal laws that could be used to address environmental and occupational public health risks.

    Science.gov (United States)

    Fry, Jillian P; Love, David C; Shukla, Arunima; Lee, Ryan M

    2014-11-19

    Half of the world's edible seafood comes from aquaculture, and the United States (US) government is working to develop an offshore finfish aquaculture industry in federal waters. To date, US aquaculture has largely been regulated at the state level, and creating an offshore aquaculture industry will require the development of a new regulatory structure. Some aquaculture practices involve hazardous working conditions and the use of veterinary drugs, agrochemicals, and questionable farming methods, which could raise environmental and occupational public health concerns if these methods are employed in the offshore finfish industry in the US. This policy analysis aims to inform public health professionals and other stakeholders in the policy debate regarding how offshore finfish aquaculture should be regulated in the US to protect human health; previous policy analyses on this topic have focused on environmental impacts. We identified 20 federal laws related to offshore finfish aquaculture, including 11 that are relevant to preventing, controlling, or monitoring potential public health risks. Given the novelty of the industry in the US, myriad relevant laws, and jurisdictional issues in an offshore setting, federal agencies need to work collaboratively and transparently to ensure that a comprehensive and functional regulatory structure is established that addresses the potential public health risks associated with this type of food production.

  17. Offshore Finfish Aquaculture in the United States: An Examination of Federal Laws That Could be Used to Address Environmental and Occupational Public Health Risks

    Directory of Open Access Journals (Sweden)

    Jillian P. Fry

    2014-11-01

    Full Text Available Half of the world’s edible seafood comes from aquaculture, and the United States (US government is working to develop an offshore finfish aquaculture industry in federal waters. To date, US aquaculture has largely been regulated at the state level, and creating an offshore aquaculture industry will require the development of a new regulatory structure. Some aquaculture practices involve hazardous working conditions and the use of veterinary drugs, agrochemicals, and questionable farming methods, which could raise environmental and occupational public health concerns if these methods are employed in the offshore finfish industry in the US. This policy analysis aims to inform public health professionals and other stakeholders in the policy debate regarding how offshore finfish aquaculture should be regulated in the US to protect human health; previous policy analyses on this topic have focused on environmental impacts. We identified 20 federal laws related to offshore finfish aquaculture, including 11 that are relevant to preventing, controlling, or monitoring potential public health risks. Given the novelty of the industry in the US, myriad relevant laws, and jurisdictional issues in an offshore setting, federal agencies need to work collaboratively and transparently to ensure that a comprehensive and functional regulatory structure is established that addresses the potential public health risks associated with this type of food production.

  18. Mixed convection from a discrete heat source in enclosures with two adjacent moving walls and filled with micropolar nanofluids

    Directory of Open Access Journals (Sweden)

    Sameh E. Ahmed

    2016-03-01

    Full Text Available This paper examines numerically the thermal and flow field characteristics of the laminar steady mixed convection flow in a square lid-driven enclosure filled with water-based micropolar nanofluids by using the finite volume method. While a uniform heat source is located on a part of the bottom of the enclosure, both the right and left sidewalls are considered adiabatic together with the remaining parts of the bottom wall. The upper wall is maintained at a relatively low temperature. Both the upper and left sidewalls move at a uniform lid-driven velocity and four different cases of the moving lid ordinations are considered. The fluid inside the enclosure is a water based micropolar nanofluid containing different types of solid spherical nanoparticles: Cu, Ag, Al2O3, and TiO2. Based on the numerical results, the effects of the dominant parameters such as Richardson number, nanofluid type, length and location of the heat source, solid volume fractions, moving lid orientations and dimensionless viscosity are examined. Comparisons with previously numerical works are performed and good agreements between the results are observed. It is found that the average Nusselt number along the heat source decreases as the heat source length increases while it increases when the solid volume fraction increases. Also, the results of the present study indicate that both the local and the average Nusselt numbers along the heat source have the highest value for the fourth case (C4. Moreover, it is observed that both the Richardson number and moving lid ordinations have a significant effect on the flow and thermal fields in the enclosure.

  19. Optimization of aquaculture systems in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, M. [Instituto Ciencias de la Construccion Eduardo Torroja, Madrid (Spain); Carrillo, M. [Instituto de Acuicultura de Torre la Sal, Castellon (Spain)

    1997-12-31

    An analysis of present heat production systems, using fossil fuel combustion, employed for sea water heating in Spanish hatcheries is given in this paper and compared to a technical solution based on the employment of a heat pump. Price per unit of produced energy is calculated for each system using liquid and gaseous fuels, and then these prices are compared to the price obtained for a heat pump. The heat pump system is also compared, from the point of view of its precision in maintaining temperatures, to the systems used at the present. A project prototype for thermal conditioning and temperature control in aquaculture rearing tanks is described. (author)

  20. Managing the system validation of the DKIST enclosure

    Science.gov (United States)

    Ariño, Javier; Gómez, Celia; Murga, Gaizka; Ampuero, Pedro; Campo, Ramon

    2014-08-01

    The size of the DKIST (formerly ATST) Enclosure, similar to the 8-10 meters class telescopes such as VLT or GTC, together with the strict and demanding requirement of using the azimuth and shutter movement for accurate positioning of the entrance aperture stop while tracking, makes it probably the most complex enclosure built up to date. Thus, managing the system validation becomes a challenging task, in which the singularity of this system has to be considered by applying customized tools and processes in addition to the usual procedures. This paper describes the managing process followed towards DKIST Enclosure validation, focused on ensuring final on-site assembly and performance. During the design phase, the system verification was carried out by means of modeling tools and detailed simulations and calculations. Furthermore, an overall BIM (Building Information Model) was built to integrate all the design work and detect potential problems since the design phase; it was used to check interfaces between subsystems, verify accessibility for maintenance and study the construction process. The Factory Assembly and Testing phase (FA&T) test campaign, recently finished, has been oriented towards the final system validation, by testing: 1) the overall system integration; 2) the performance; 3) the simulation of the final on-site assembly. The importance of guaranteeing a correct on-site assembly has driven also the decision towards the installation of a modular prefabricated cladding, which reduces the risk inherent to the site remoteness and the on-site installation of the outer water-cooled skin. The validation process also included early prototyping and testing of critical subsystems. That being said, all this helps reducing the risk significantly during the final on-site assembly and commissioning through the replication of already validated procedures.

  1. Aqua-Topics. Aquaculture for Youth and Youth Educators.

    Science.gov (United States)

    McVey, Eileen

    This booklet contains information on aquaculture and ideas for aquaculture projects. The information provided is for students at upper elementary through high school learning levels. Recommended activities at the end of the text are organized by level of difficulty. The activities can be modified depending on area and availability of resources. A…

  2. Major bacterial diseases in aquaculture and their vaccine development

    Science.gov (United States)

    Aquaculture is emerging as the fastest growing food-producing industry in the world due to the increasing demand for food fish consumption. However, the intensive culture of food fish has led to outbreaks of various bacterial diseases, resulting in annual economic losses to the aquaculture industry ...

  3. Nutrients valorisation via Duckweed-based wastewater treatment and aquaculture

    NARCIS (Netherlands)

    Mohamed El-Shafai, S.A.A.

    2004-01-01

    Development of a sustainable wastewater treatment scheme to recycle sewage nutrients and water in tilapia aquaculture was the main objective of this PhD research. Use of an Integrated UASB-duckweed ponds system for domestic wastewater treatment linked to tilapia aquaculture was investigated. The tr

  4. Does aquaculture add resilience to the global food system?

    NARCIS (Netherlands)

    Troell, M.; Naylor, R.; Metian, M.; Beveridge, M.; Tyedmers, P.H.; Folke, C.; Arrow, K.J.; Barrett, S.; Crépin, A.S.; Ehrlich, P.; Gren, A.; Kautsky, N.; Levin, S.A.; Nyborg, K.; Osterblom, H.; Polasky, S.; Scheffer, M.; Walker, B.; Xepapadeas, A.; de Zeeuw, A.J.

    2014-01-01

    Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment t

  5. Vaccines for fish in aquaculture.

    Science.gov (United States)

    Sommerset, Ingunn; Krossøy, Bjørn; Biering, Eirik; Frost, Petter

    2005-02-01

    Vaccination plays an important role in large-scale commercial fish farming and has been a key reason for the success of salmon cultivation. In addition to salmon and trout, commercial vaccines are available for channel catfish, European seabass and seabream, Japanese amberjack and yellowtail, tilapia and Atlantic cod. In general, empirically developed vaccines based on inactivated bacterial pathogens have proven to be very efficacious in fish. Fewer commercially available viral vaccines and no parasite vaccines exist. Substantial efficacy data are available for new fish vaccines and advanced technology has been implemented. However, before such vaccines can be successfully commercialized, several hurdles have to be overcome regarding the production of cheap but effective antigens and adjuvants, while bearing in mind environmental and associated regulatory concerns (e.g., those that limit the use of live vaccines). Pharmaceutical companies have performed a considerable amount of research on fish vaccines, however, limited information is available in scientific publications. In addition, salmonids dominate both the literature and commercial focus, despite their relatively small contribution to the total volume of farmed fish in the world. This review provides an overview of the fish vaccines that are currently commercially available and some viewpoints on how the field is likely to evolve in the near future.

  6. Five design options for permanent total enclosures (PTEs)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper discusses how companies in the printing industry are looking more to the use of permanent total enclosures (PTEs) as a means to demonstrate compliance with new Clean Air Act standards for hazardous air pollutants. The advantages of this method is that by following design guidelines and meeting the EPA five point criteria for a fully enclosed room, then one may assume 100% capture of contaminants. This factor often raises the advantages of this method over other control methods which put the responsibility upon the user to demonstrate compliance with required control levels.

  7. Identification of ancient paths within the Late Bronze Age enclosure Corneşti-Iarcuri, western Romania

    Science.gov (United States)

    Nykamp, Moritz; Heeb, Bernhard S.; Hoelzmann, Philipp; Knitter, Daniel; Krause, Jan; Krause, Rüdiger; Szentmiklosi, Alexandru; Schütt, Brigitta

    2016-04-01

    This study applies a landscape archaeological approach, combining geoscientific and archaeological data, to shed light into the Holocene landscape development in the environs of the Late Bronze Age enclosure of Corneşti-Iarcuri, Romania. Corneşti-Iarcuri is located at the eastern edge of the Great Hungarian Plain and represents with its four earth-filled wooden ramparts the largest known prehistoric enclosure in Europe. Late Bronze Age settlements are documented for the two innermost enclosures. However, the settlement history in its environs started already in the Copper Age. The aims of this study are i) to link hydro-morphological relief anomalies to evidences of settlement occurrence and ii) to document the variations of Holocene geomorphic activity and stability in a selected sub-catchment. The spatio-temporal relation between unnaturally bending tributaries and settled areas is uncovered and the involved formation processes are discussed. The morphometric analyses of the tributaries in the built-up area of Iarcuri show a clear tendency: unnaturally bending tributaries most often occur in the central valley and tend to cluster in the central part between the two innermost enclosures. By comparison of the locations of the strongly bending tributaries and the locations of the most densely settled areas it appears that both are related. It is well known that such linear features form in relation to settlements as a consequence of repeated passage of humans. Due to soil compaction along regular footpaths and the resulting reduced infiltration capacity gully erosion tends to occur forming hollow ways. Usually these hollow ways form contemporaneously with or subsequent to the occupation period of the site. As a consequence alluvial fans form at the outlet of the tributaries documenting former settlement and geomorphic activities. A sediment core obtained from the alluvial fan dumped by the tributary sourcing in the densely settled southern part of enclosure II

  8. Mechanisms of antimicrobial resistance in finfish aquaculture environments

    Directory of Open Access Journals (Sweden)

    Claudio D. Miranda

    2013-08-01

    Full Text Available Consumer demand for affordable fish drives the ever-growing global aquaculture industry. The intensification and expansion of culture conditions in the production of several finfish species has been coupled with an increase in bacterial fish disease and the need for treatment with antimicrobials. Understanding the molecular mechanisms of antimicrobial resistance prevalent in aquaculture environments is important to design effective disease treatment strategies, to prioritize the use and registration of antimicrobials for aquaculture use, and to assess and minimize potential risks to public health. In this brief article we provide an overview of the molecular mechanisms of antimicrobial resistance mechanisms in finfish aquaculture environments and highlight specific research that should provide the basis of sound, science-based policies for the use of antimicrobials in aquaculture.

  9. Offshore aquaculture: Spatial planning principles for sustainable development.

    Science.gov (United States)

    Gentry, Rebecca R; Lester, Sarah E; Kappel, Carrie V; White, Crow; Bell, Tom W; Stevens, Joel; Gaines, Steven D

    2017-01-01

    Marine aquaculture is expanding into deeper offshore environments in response to growing consumer demand for seafood, improved technology, and limited potential to increase wild fisheries catches. Sustainable development of aquaculture will require quantification and minimization of its impacts on other ocean-based activities and the environment through scientifically informed spatial planning. However, the scientific literature currently provides limited direct guidance for such planning. Here, we employ an ecological lens and synthesize a broad multidisciplinary literature to provide insight into the interactions between offshore aquaculture and the surrounding environment across a spectrum of spatial scales. While important information gaps remain, we find that there is sufficient research for informed decisions about the effects of aquaculture siting to achieve a sustainable offshore aquaculture industry that complements other uses of the marine environment.

  10. Antimicrobial resistance and antimicrobial resistance genes in marine bacteria from salmon aquaculture and non-aquaculture sites.

    Science.gov (United States)

    Shah, Syed Q A; Cabello, Felipe C; L'abée-Lund, Trine M; Tomova, Alexandra; Godfrey, Henry P; Buschmann, Alejandro H; Sørum, Henning

    2014-05-01

    Antimicrobial resistance (AR) detected by disc diffusion and antimicrobial resistance genes detected by DNA hybridization and polymerase chain reaction with amplicon sequencing were studied in 124 marine bacterial isolates from a Chilean salmon aquaculture site and 76 from a site without aquaculture 8 km distant. Resistance to one or more antimicrobials was present in 81% of the isolates regardless of site. Resistance to tetracycline was most commonly encoded by tetA and tetG; to trimethoprim, by dfrA1, dfrA5 and dfrA12; to sulfamethizole, by sul1 and sul2; to amoxicillin, by blaTEM ; and to streptomycin, by strA-strB. Integron integrase intl1 was detected in 14 sul1-positive isolates, associated with aad9 gene cassettes in two from the aquaculture site. intl2 Integrase was only detected in three dfrA1-positive isolates from the aquaculture site and was not associated with gene cassettes in any. Of nine isolates tested for conjugation, two from the aquaculture site transferred AR determinants to Escherichia coli. High levels of AR in marine sediments from aquaculture and non-aquaculture sites suggest that dispersion of the large amounts of antimicrobials used in Chilean salmon aquaculture has created selective pressure in areas of the marine environment far removed from the initial site of use of these agents.

  11. ENCLOSURE EXPERIMENTS ON AND LACUSTRINE PRACTICE FOR ELIMINATING MICROCYSTIS BLOOM

    Institute of Scientific and Technical Information of China (English)

    刘建康; 谢平

    2002-01-01

    Microcystis bloom, one of the most objectionable characteristics of eutrophication in tropical and subtropical waters, occurred in Donghu Lake (East Lake) of Wuhan every summer from the 1970s up to 1984, but from 1985 up tonow failed to occur there. The cause of its disappearance remained in obscurityuntil recently. In situ enclosure experiments in the lake for three years showed that the stocking of the filter-feeding silver carp (Hypophthalmichthys molitrix) and big-head carp (Aristichthys nobilis) played a decisive role in eliminating Microcystis bloom from the lake; but that recurrence of the bloom is possibleunder certain conditions. This paper presents the details and the results of enclosure experiments. The authors' analysis of fish biomass data obtained by echo-sounding and the fishery production of the lake over the years, revealed that the recurrence of Microcystis bloom can be prevented so long as the combined biomass of silver carp and big-head carp remains at or exceeds 50 g per cubic meter of lakewater, as was the case in the lake's 1985 fish yield of 1015 t.``

  12. Capturing ecosystem services, stakeholders' preferences and trade-offs in coastal aquaculture decisions: a Bayesian belief network application.

    Directory of Open Access Journals (Sweden)

    Laetitia Helene Marie Schmitt

    Full Text Available Aquaculture activities are embedded in complex social-ecological systems. However, aquaculture development decisions have tended to be driven by revenue generation, failing to account for interactions with the environment and the full value of the benefits derived from services provided by local ecosystems. Trade-offs resulting from changes in ecosystem services provision and associated impacts on livelihoods are also often overlooked. This paper proposes an innovative application of Bayesian belief networks - influence diagrams - as a decision support system for mediating trade-offs arising from the development of shrimp aquaculture in Thailand. Senior experts were consulted (n = 12 and primary farm data on the economics of shrimp farming (n = 20 were collected alongside secondary information on ecosystem services, in order to construct and populate the network. Trade-offs were quantitatively assessed through the generation of a probabilistic impact matrix. This matrix captures nonlinearity and uncertainty and describes the relative performance and impacts of shrimp farming management scenarios on local livelihoods. It also incorporates export revenues and provision and value of ecosystem services such as coastal protection and biodiversity. This research shows that Bayesian belief modeling can support complex decision-making on pathways for sustainable coastal aquaculture development and thus contributes to the debate on the role of aquaculture in social-ecological resilience and economic development.

  13. Capturing ecosystem services, stakeholders' preferences and trade-offs in coastal aquaculture decisions: a Bayesian belief network application.

    Science.gov (United States)

    Schmitt, Laetitia Helene Marie; Brugere, Cecile

    2013-01-01

    Aquaculture activities are embedded in complex social-ecological systems. However, aquaculture development decisions have tended to be driven by revenue generation, failing to account for interactions with the environment and the full value of the benefits derived from services provided by local ecosystems. Trade-offs resulting from changes in ecosystem services provision and associated impacts on livelihoods are also often overlooked. This paper proposes an innovative application of Bayesian belief networks - influence diagrams - as a decision support system for mediating trade-offs arising from the development of shrimp aquaculture in Thailand. Senior experts were consulted (n = 12) and primary farm data on the economics of shrimp farming (n = 20) were collected alongside secondary information on ecosystem services, in order to construct and populate the network. Trade-offs were quantitatively assessed through the generation of a probabilistic impact matrix. This matrix captures nonlinearity and uncertainty and describes the relative performance and impacts of shrimp farming management scenarios on local livelihoods. It also incorporates export revenues and provision and value of ecosystem services such as coastal protection and biodiversity. This research shows that Bayesian belief modeling can support complex decision-making on pathways for sustainable coastal aquaculture development and thus contributes to the debate on the role of aquaculture in social-ecological resilience and economic development.

  14. A simple formula for insertion loss prediction of large acoustical enclosures using statistical energy analysis method

    Directory of Open Access Journals (Sweden)

    Kim Hyun-Sil

    2014-12-01

    Full Text Available Insertion loss prediction of large acoustical enclosures using Statistical Energy Analysis (SEA method is presented. The SEA model consists of three elements: sound field inside the enclosure, vibration energy of the enclosure panel, and sound field outside the enclosure. It is assumed that the space surrounding the enclosure is sufficiently large so that there is no energy flow from the outside to the wall panel or to air cavity inside the enclosure. The comparison of the predicted insertion loss to the measured data for typical large acoustical enclosures shows good agreements. It is found that if the critical frequency of the wall panel falls above the frequency region of interest, insertion loss is dominated by the sound transmission loss of the wall panel and averaged sound absorption coefficient inside the enclosure. However, if the critical frequency of the wall panel falls into the frequency region of interest, acoustic power from the sound radiation by the wall panel must be added to the acoustic power from transmission through the panel.

  15. Mixed convection inside nanofluid filled rectangular enclosures with moving bottom wall

    Directory of Open Access Journals (Sweden)

    Mahmoodi Mostafa

    2011-01-01

    Full Text Available The mixed convection fluid flow and heat transfer in lid-driven rectangular enclosures filled with the Al2O3-water nanofluid is investigated numerically. The left and the right vertical walls as well as the top horizontal wall of the enclosure are maintained at a constant cold temperature Tc. The bottom horizontal wall of the enclosure, which moves from left to right, is kept at a constant hot temperature Th, with Th>Tc. The governing equations written in terms of the primitive variables are solved using the finite volume method and the SIMPLER algorithm. Using the developed code, a parametric study is performed and the effects of the Richardson number, the aspect ratio of the enclosure and the volume fraction of the nanoparticles on the fluid flow and heat transfer inside the enclosure are investigated. The results show that at low Richardson numbers, a primary counterclockwise vortex is formed inside the enclosure. More over it is found that for the range of the Richardson number considered, 10-1-101, the average Nusselt number of the hot wall, increases with increasing the volume fraction of the nanoparticles. Also it is observed that the average Nusselt number of the hot wall of tall enclosures is more that to that of the shallow enclosures.

  16. Cascading trophic interactions in the littoral zone: an enclosure experiment in shallow Lake Stigsholm, Denmark

    DEFF Research Database (Denmark)

    Jeppesen, E.; Søndergaard, M.; Christoffersen, K.;

    2002-01-01

    polyethylene enclosures, which 2.5 month prior to the experiments were mounted above the water surface on a stainless steel ring to allow development of natural pelagic, benthic and epiphytic communities. Half of the enclosures were kept free of plants by harvesting. In late July, the sheets were released from...

  17. Interactions between piscivores, zooplanktivores and zooplankton in submerged macrophytes : Preliminary observations from enclosure and pond experiments

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Perrow, M.R.; Landkildehus, F.

    1997-01-01

    and the presence of zooplanktivores typically changed the habitat selection of cladoceran zooplankton. In the case of piscivore/zooplanktivore interactions, the risk of predation was enough to generate clear responses even where the losses to predation were low. However, only in the enclosure experiment...... suggest that this mechanism is plausible with the set of piscivores (pike Esox lucius and perch Perca fluviatilis) and the zooplanktivores (0+ roach Rutilus rutilus and perch) common in temperate Europe. The presence of piscivores typically changed the habitat use and the activity level of zooplanktivores...... of foraging within structured habitats) of the predator (both piscivore and zooplanktivore), absolute and relative densities of predator and prey and predator dietary choice....

  18. Analysis of structural - acoustic coupling of elastic rectangular enclosure with arbitrary boundary conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structural acoustic coupling characteristics of a rectangular enclosure consisting of two elastic supported flexible plates and four rigid plates are analyzed. A general formulation considering the full coupling between the plates and cavity is developed by using Hamiltonian function and Rayleigh-Ritz method. By means of continuous distributions of artificial springs along boundary of flexible plates, a wide variety of boundary conditions and structure joint conditions are considered. To demonstrate the validity of the analytical model,the responses of sound pressure in the cavity and plate velocity are worked out. The analytical results coincides well with Kim's experimental results. The result is satisfactory. Finally, analytical results on the structure vibration and the sound field inside the cavity are presented.These results indicate that the coupling of the combined structure is relatively weak, so the internal cavity sound is controlled by plate directly excited,and the translational stiffness affects the sound more than the rotational stiffness does.

  19. Salmon aquaculture and antimicrobial resistance in the marine environment.

    Science.gov (United States)

    Buschmann, Alejandro H; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A; Henríquez, Luis A; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P; Cabello, Felipe C

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.

  20. Antibacterial Resistance in African Catfish Aquaculture: a Review

    Directory of Open Access Journals (Sweden)

    Madubuike U. ANYANWU

    2016-03-01

    Full Text Available Antibacterial resistance (AR is currently one of the greatest threats to mankind as it constitutes health crisis. Extensive use of antibacterial agents in human and veterinary medicine, and farm crops have resulted in emergence of antibacterial-resistant organisms in different environmental settings including aquaculture. Antibacterial resistance in aquaculture is a serious global concern because antibacterial resistance genes (ARGs can be transferred easily from aquaculture setting to other ecosystems and the food chain. African catfish (ACF aquaculture has increased at a phenomenal rate through a continuous process of intensification, expansion and diversification. Risk of bacterial diseases has also increased and consequently there is increased use of antibacterial agents for treatment. Antibacterial resistance in ACF aquaculture has huge impact on the food chain and thus represents risk to public and animal health. In “one health” approach of curbing AR, knowledge of the sources, mechanisms and magnitude of AR in ACF aquaculture and its potential impact on the food chain is important in designing and prioritizing monitoring programs that may generate data that would be relevant for performing quantitative risk assessments, implementation of antibacterial stewardship plans, and developing effective treatment strategies for the control of ACF disease and reducing risk to public health. This review provides insight on the sources, mechanisms, prevalence and impact of antibacterial resistance in ACF aquaculture environment, a setting where the impact of AR is neglected or underestimated.

  1. Nitrous oxide (N2O) emission from aquaculture: a review.

    Science.gov (United States)

    Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Khanal, Samir Kumar

    2012-06-19

    Nitrous oxide (N(2)O) is an important greenhouse gas (GHG) which has a global warming potential 310 times that of carbon dioxide (CO(2)) over a hundred year lifespan. N(2)O is generated during microbial nitrification and denitrification, which are common in aquaculture systems. To date, few studies have been conducted to quantify N(2)O emission from aquaculture. Additionally, very little is known with respect to the microbial pathways through which N(2)O is formed in aquaculture systems. This review suggests that aquaculture can be an important anthropogenic source of N(2)O emission. The global N(2)O-N emission from aquaculture in 2009 is estimated to be 9.30 × 10(10) g, and will increase to 3.83 × 10(11)g which could account for 5.72% of anthropogenic N(2)O-N emission by 2030 if the aquaculture industry continues to increase at the present annual growth rate (about 7.10%). The possible mechanisms and various factors affecting N(2)O production are summarized, and two possible methods to minimize N(2)O emission, namely aquaponic and biofloc technology aquaculture, are also discussed. The paper concludes with future research directions.

  2. Does aquaculture add resilience to the global food system?

    Science.gov (United States)

    Troell, Max; Naylor, Rosamond L; Metian, Marc; Beveridge, Malcolm; Tyedmers, Peter H; Folke, Carl; Arrow, Kenneth J; Barrett, Scott; Crépin, Anne-Sophie; Ehrlich, Paul R; Gren, Asa; Kautsky, Nils; Levin, Simon A; Nyborg, Karine; Österblom, Henrik; Polasky, Stephen; Scheffer, Marten; Walker, Brian H; Xepapadeas, Tasos; de Zeeuw, Aart

    2014-09-16

    Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment to, or an opportunity for, enhanced resilience in the global food system given increased resource scarcity and climate change. Aquaculture can potentially enhance resilience through improved resource use efficiencies and increased diversification of farmed species, locales of production, and feeding strategies. However, aquaculture's reliance on terrestrial crops and wild fish for feeds, its dependence on freshwater and land for culture sites, and its broad array of environmental impacts diminishes its ability to add resilience. Feeds for livestock and farmed fish that are fed rely largely on the same crops, although the fraction destined for aquaculture is presently small (∼4%). As demand for high-value fed aquaculture products grows, competition for these crops will also rise, as will the demand for wild fish as feed inputs. Many of these crops and forage fish are also consumed directly by humans and provide essential nutrition for low-income households. Their rising use in aquafeeds has the potential to increase price levels and volatility, worsening food insecurity among the most vulnerable populations. Although the diversification of global food production systems that includes aquaculture offers promise for enhanced resilience, such promise will not be realized if government policies fail to provide adequate incentives for resource efficiency, equity, and environmental protection.

  3. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    Science.gov (United States)

    Kathleen, M. M.; Felecia, C.; Reagan, E. L.; Kasing, A.; Lesley, M.; Toh, S. C.

    2016-01-01

    The administration of antimicrobials in aquaculture provides a selective pressure creating a reservoir of multiple resistant bacteria in the cultured fish and shrimps as well as the aquaculture environment. The objective of this study was to determine the extent of antibiotic resistance in aquaculture products and aquaculture's surrounding environment in Sarawak, Malaysian Borneo. Ninety-four identified bacterial isolates constituted of 17 genera were isolated from sediment, water, and cultured organisms (fish and shrimp) in selected aquaculture farms. These isolates were tested for their antibiotic resistance against 22 antibiotics from several groups using the disk diffusion method. The results show that the highest resistance was observed towards streptomycin (85%, n = 20), while the lowest resistance was towards gentamicin (1.1%, n = 90). The multiple antibiotic resistant (MAR) index of the isolates tested ranged between 0 and 0.63. It was suggested that isolates with MAR index > 0.2 were recovered from sources with high risk of antibiotic resistant contamination. This study revealed low level of antibiotic resistance in the aquaculture bacterial isolates except for streptomycin and ampicillin (>50% resistance, n = 94) which have been used in the aquaculture industry for several decades. Antibiotic resistant patterns should be continuously monitored to predict the emergence and widespread of MAR. Effective action is needed to keep the new resistance from further developing and spreading.

  4. Key Performance Characteristics of Organic Shrimp Aquaculture in Southwest Bangladesh

    Directory of Open Access Journals (Sweden)

    Christian Reinhard Vogl

    2012-05-01

    Full Text Available In Bangladesh, black tiger shrimp (Penaeus monodon; Fabricius, 1798 aquaculture has come to be one of the most important sectors in both the rural and national economies. Likewise, organic shrimp aquaculture has emerged as an alternative farming enterprise for farmers especially in the southwestern districts of Bangladesh. The present study aims to show key performance characteristics of organic shrimp farmers and farming in a prototypical shrimp farming area in Bangladesh. Data was collected in 2009 from organic shrimp farmers in the Kaligonj and Shyamnagar sub-districts through questionnaire interviews, transect walks and focus group discussions. The mean productivity of organic shrimp farming in the area is 320 kg ha−1 yr−1 (ranging from 120 to 711 kg ha−1year−1. Organic farmers are more likely to have a higher monthly income and less aquaculture experience. Moreover, suitable landholdings and classified labor distribution have been found to play an important role in the development of organic shrimp aquaculture. The most common assets of organic shrimp aquaculture are high yield, low production cost, available post larvae and high market prices. Small business farmers are likely to earn more income benefits from organic shrimp aquaculture than their larger-scale counterparts. Finally, the paper suggests that more research is needed to stimulate the success of organic shrimp aquaculture.

  5. Evaluation of winter food quality and its variability for red deer in forest environment: overwintering enclosures vs. free-ranging areas

    Directory of Open Access Journals (Sweden)

    Holá Michaela

    2016-09-01

    Full Text Available Populations of European ungulates have grown substantially over recent decades, resulting in considerable environmental and socio-economic impacts. Availability and quality of natural and supplemental food sources are among the main factors driving their population dynamics. Detailed knowledge of food quality of management-targeted species is therefore of primary importance for their successful management. The main aim of this study was to evaluate winter food quality and its variability for an important ungulate species in the Czech Republic - i.e. red deer, using faecal indices (faecal nitrogen, faecal acid detergent fibre, faecal neutral detergent fibre and near infrared reflectance spectroscopy. We compared food quality for red deer and its possible differences between overwintering enclosures (i.e. fenced areas where red deer spend harsh winter conditions and neighbouring unfenced free-ranging areas within two study areas. The results obtained showed that winter food quality and its variability for red deer are of different quality and variability in the overwintering enclosure and neighbouring free-ranging area. The observed differences in concentrations and amounts of variation of faecal indices are most probably related to animal densities at individual study areas. Wildlife managers should therefore keep animals in overwintering enclosures at moderate densities and to provide high quality forage to all individuals in order to balance nutrition of both the individuals inside and outside the enclosures. Nevertheless, further studies are needed in order to provide deeper knowledge on red deer food quality and its variability in space and time.

  6. Space use selectivity by chimpanzees and gorillas in an indoor-outdoor enclosure.

    Science.gov (United States)

    Ross, S R; Calcutt, S; Schapiro, S J; Hau, J

    2011-02-01

    Understanding the relationship between physical environments and nonhuman primate behavior is a key element for effective care and management in a range of settings. The physical features of the captive environment, including not only gross useable space but also environmental complexity, can have a significant influence on primate behavior and ultimately, animal welfare. But despite this connection, there remains relatively little conclusive data on how captive primates, especially great apes, use the spaces provided to them, especially in modern, indoor-outdoor enclosures that have become more prevalent in recent years. In this study, we used four years of detailed data on where 23 great apes (chimpanzees and gorillas) positioned themselves within a modern, indoor-outdoor zoo enclosure to determine not only how the apes utilized their space but also how access to outdoor areas affected their spatial selectivity. We found that both species used relatively little of their available space: chimpanzees and gorillas spent half their time in only 3.2 and 1.5% of their useable three-dimensional space, respectively. Chimpanzees utilized the outdoor space more than gorillas, but access to the outdoors did not affect space selectivity in the indoor area for either species. Although both species of ape were highly selective in their space use, consideration should be given to the importance of providing the choice to locate in a variety of spaces, including outdoor areas. These data represent an extremely detailed account of space selectivity by great apes in an indoor-outdoor environment and have substantial implications for future facility design and captive primate management.

  7. THE FISHERIES AND AQUACULTURE COMPONENT OF RURAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Adrian ZUGRAVU

    2006-01-01

    Full Text Available Fisheries and aquaculture can provide a key contribution to food security and poverty alleviation. Fisheries and aquaculture policy is an instrument for the conservation and management of fisheries and aquaculture. It was created with the aims of managing a common resource. Fisheries policies and management strategies the world over is in a state of flux, continued attempts to use fisheriesas the key to solving a complex web of social and economic issues threaten to overwhelm the basic fact that, if this resources are overfished, they will not sustain either social or development.

  8. Design and analysis of the NFIRAOS thermal optics enclosure

    Science.gov (United States)

    Fitzsimmons, Joeleff; Andersen, David; Atwood, Jenny; Byrnes, Peter; Herriot, Glen; Hill, Alexis; Szeto, Kei

    2016-08-01

    The Narrow Field InfraRed Adaptive Optics System (NFIRAOS) will be the first-light facility adaptive optics system for the Thirty Meter Telescope (TMT). In order to meet the optical performance and stability specifications essential to leveraging the extraordinary capabilities of the TMT, all of the optical components within NFIRAOS will be protected within a large thermally-controlled optics enclosure (ENCL). Among the many functions performed by the ENCL, the most critical functions include providing a highly stable, light-tight, cold, dry environment maintained at 243±0.5 K for the NFIRAOS opto-mechanical sub-systems and supporting TABL structure. Although the performance of the ENCL during the science operation of NFIRAOS is critical, the maximum thermal loading will be defined by the cooldown/ warm-up cycle which must be accomplished within a time-frame that will minimize the on-sky operational impact due to daytime maintenance work. This study describes the thermal/mechanical design development and supporting analyses (analytical and finite element analyses (FEA)) completed during the preliminary design phase and through the current progression of the ENCL final design phase. The walls of the ENCL consist of interlocking, multilayered, thermally insulated panels, which are supported by an externally located structural framework which attaches to the NFIRAOS Instrument Support Structure. The regulation of the interior ENCL wall surface temperature to within ±0.5 K requires that the heat flux into the interior of NFIRAOS be eliminated by cooling a thermal conduction plate embedded between multiple layers of insulation. The thermal design of the enclosure was evaluated for both steady-state (SS) performance and transient performance (cool-down and warm-up cycles). The transient analysis utilizes a hybrid of a one-dimensional thermal network approach combined with three-dimensional conjugate heat transfer analyses of explicit opto-mechanical components within

  9. 29 CFR 1928.53 - Protective enclosures for wheel-type agricultural tractors-test procedures and performance...

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Protective enclosures for wheel-type agricultural tractors... enclosures for wheel-type agricultural tractors—test procedures and performance requirements. (a) Purpose... enclosure designed for wheel-type agricultural tractors to minimize the frequency and severity of...

  10. Photoinactivation of major bacterial pathogens in aquaculture

    Directory of Open Access Journals (Sweden)

    Heyong Jin Roh

    2016-08-01

    Full Text Available Abstract Background Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and 68.4 J cm−2, respectively, produced one log reduction in the bacterial populations, whereas Streptococcus parauberis was the least susceptible (153.8 J cm−2 per one log reduction. In general, optical density (OD values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.

  11. Management options to mitigate environmental impact of aquaculture in the Philippines

    OpenAIRE

    Edpalina, Rizalita Rosalejos

    2009-01-01

    Asia-Pacific represents the most important region for fisheries and aquaculture production. It is world's largest contributor to the world's aquaculture, producing 46.9 million tons or 91% of the global aquaculture production (FAO, 2005). The growth of aquaculture production has been very strong for the last ten years due to the increased production from China. The aquaculture production in Southeast Asia is diversified comprising 41.6% freshwater fish, 23.5% of aquatic plants, 6.7% crustacea...

  12. Natatorium Building Enclosure Deterioration Due to Moisture Migration

    Directory of Open Access Journals (Sweden)

    Aleka Pappas

    2012-12-01

    Full Text Available The natatorium enclosure at the Avon Recreation Center in Avon, Colorado experienced significant deterioration of the CMU façade due to moisture carried by humid air from the interior of the space into the wall assembly. This situation was caused by a combination of an insufficient interior air and vapor barrier along with an HVAC system that failed to provide negative pressurization to the space. This case study describes the investigation carried out to determine the causes of wall and roof deterioration at the building, and details the repair efforts undertaken. Lessons learned are presented to help designers, building owners, and maintenance personnel prevent similar problems from occurring in their buildings.

  13. Third millennium BC ditched enclosures in central Iberia

    Directory of Open Access Journals (Sweden)

    Díaz del Río, Pedro

    2003-12-01

    Full Text Available This article examines contextual data from three Copper Age ditched enclosures excavated between 1997 and 2001 in the middle Tagus basin. Calibrated radiocarbon dates suggest that they were all constructed and backfilled during the first half of the third millennium BC. Key characteristics are their heterogeneous topographic position, variable visibility, small size and high density of features and domestic refuse. All evidence supports their interpretation as small occupation sites. Finally, we discuss the role of ditched enclosures in their contemporary regional and Iberian context. We suggest that their variability is a result of diverse aggregation and fission dynamics characterisitic of segmentary societies.

    Este trabajo presenta la primera información contextual de tres recintos de fosos calcolíticos excavados entre 1997 y 2001 en el valle medio del Tajo (Comunidad de Madrid. La serie de dataciones absolutas de dos de ellos indica que fueron construidos y colmatados en la primera mitad del III milenio cal AC. Se trata de recintos de pequeño tamaño, heterogéneos en cuanto a su posición topográfica, variables respecto a su arco de visibilidad y con escasa racionalidad defensiva. Todo el registro apunta a espacios habitados de forma permanente. Por último se discute el papel de los recintos de fosos en el contexto regional y Peninsular. Sugerimos que su variabilidad es el resultado de distintas dinámicas de agregación y fisión características de sociedades segmentarias.

  14. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    DEFF Research Database (Denmark)

    Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche;

    2012-01-01

    An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social...... and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–environment interactions and policy-related developments and decisions. The Drivers-Pressures-State Change...... to assess DPSIR framework components, are reviewed with a focus on the key environmental issues associated with bivalve farming. Indicator selection criteria are provided to facilitate constraining the number of indicators within the management framework. It is recommended that an ecosystem-based approach...

  15. Distribution and sources of polycyclic aromatic hydrocarbons in main aquacultural areas in Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    MASKAOUI Khalid; HU Zhong; ZHOU Junliang; HAN Yali

    2007-01-01

    The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogenic sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.

  16. The impact of water exchange rate on the health and performance of rainbow trout Oncorhynchus mykiss in recirculation aquaculture systems

    Science.gov (United States)

    Fish mortality in recirculating aquaculture systems (RAS) has been observed by the authors to increase when RAS are managed at low makeup water exchange rates with relatively high feed loading. The precise etiology of this elevated mortality was unknown, all typical water quality parameters were wit...

  17. Aquaculture Stewardship Council (ASC) ontwikkeltraject meerval : een inventarisatie

    NARCIS (Netherlands)

    Poelman, M.; Rothuis, A.J.; Bosma, R.H.

    2012-01-01

    Om een Aquaculture Stewardship Council (ASC) gecertificeerd product te krijgen is een standaard nodig, waaraan getoetst kan worden. Deze standaard geeft certificeerders een referentiekader. Pas als een standaard aanwezig is, kunnen producten gecertificeerd worden.

  18. Optimizing nitrate removal in woodchip beds treating aquaculture effluents

    DEFF Research Database (Denmark)

    von Ahnen, Mathis; Pedersen, Per Bovbjerg; Hoffmann, Carl Christian

    2016-01-01

    Nitrate is typically removed from aquaculture effluents using heterotrophic denitrification reactors. Heterotrophic denitrification reactors, however, require a constant input of readily available organic carbon (C) sources which limits their application in many aquaculture systems for practical...... the potential of optimizing woodchip reactors for treating aquaculture effluent. A central composite design (CCD) was applied to assess the effects of simultaneously changing the empty bed contact time (EBCTs of 5.0-15.0 h; corresponding to theoretical hydraulic retention times of 3.3-9.9 h) and bicarbonate...... (HCO3 -) inlet concentration (0.50-1.59 g HCO3 -/l) on the removal rate of NO3 -N, and additional organic and inorganic nutrients, in effluent deriving from an experimental recirculating aquaculture system (RAS).Volumetric NO3 -N removal rates ranged from 5.20 ± 0.02 to 8.96 ± 0.19 g/m3/day and were...

  19. Heterotrophic denitrification of aquaculture effluent using fluidized sand biofilters

    Science.gov (United States)

    The ability to consistently and cost-effectively reduce nitrate-nitrogen loads in effluent from recirculating aquaculture systems would enhance the industry's environmental stewardship and allow improved facility proximity to large markets in sensitive watersheds. Heterotrophic denitrification techn...

  20. Monitoring and managing microbes in aquaculture - Towards a sustainable industry

    DEFF Research Database (Denmark)

    Bentzon-Tilia, Mikkel; Sonnenschein, Eva; Gram, Lone

    2016-01-01

    communities to monitor water quality and to efficiently carry out ecosystem services within the aquaculture systems may only be a few years away. Initially, however, we need to thoroughly understand the microbiomes of both healthy and diseased aquaculture systems, and we need to determine how to successfully...... protect fish and larvae against disease. Hence, monitoring and manipulating the microbial communities in aquaculture environments hold great potential; both in terms of assessing and improving water quality, but also in terms of controlling the development of microbial infections. Using microbial...... manipulate and engineer these microbiomes. Similarly, we can reduce the need to apply antibiotics in aquaculture through manipulation of the microbiome, i.e. by the use of probiotic bacteria. Recent studies have demonstrated that fish pathogenic bacteria in live feed can be controlled by probiotics...

  1. Proximate analyses - Utilization of Marine Process Waste for Aquaculture Feeds

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Limited amounts of forage fish are available as an ingredient in feeds for the expanding aquaculture industry. Work is being conducted on a variety of underutilized...

  2. DIAGNOSIS OF AQUACULTURE IN THE MUNICIPALITY OF ALVARADO VERACRUZ, MEXICO

    Directory of Open Access Journals (Sweden)

    Lenin Rangel-López

    2014-07-01

    Full Text Available This research aims to analyze the current situation of aquaculture farms in the Municipality of Alvarado, Veracruz, Mexico. During this study, 29 interviews were conducted aimed to the units of aquaculture producers; 24 variables were analyzed within the aspects of the socio-economic, technical, marketing and legal framework. The most relevant results within the legal framework: 21% of units has “National Registration of Fisheries and Aquaculture” (RNPyA and 7% has “Federal Taxpayer Register” (RFC; in the socio-economic aspects: 187 jobs are generated; on technical aspects: the average area for cultivation is 410.11 ha, 79% of production is Tilapia (Oreochromis spp.. The aquaculture activity on Alvarado, Veracruz, it is in a learning process, therefore strategies are needed in order to the development of the activity and increasing production; improving cultivation methodologies and training producers on managing their aquaculture units.

  3. Aquaculture as a part of a multi-use platform

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Svenstrup Petersen, Ole; Aarup Ahrensberg, Nick

    2014-01-01

    aquaculture. These developments urgently require effective marine technology and governance solutions to facilitate installation, operation and maintenance of these novel offshore activities. Simultaneously, both economic costs and environmental impact have to remain within acceptable limits, in order...

  4. Review of the RNA Interference Pathway in Molluscs Including Some Possibilities for Use in Bivalves in Aquaculture

    Directory of Open Access Journals (Sweden)

    Leigh Owens

    2015-03-01

    Full Text Available Generalised reviews of RNA interference (RNAi in invertebrates, and for use in aquaculture, have taken for granted that RNAi pathways operate in molluscs, but inspection of such reviews show little specific evidence of such activity in molluscs. This review was to understand what specific research had been conducted on RNAi in molluscs, particularly with regard to aquaculture. There were questions of whether RNAi in molluscs functions similarly to the paradigm established for most eukaryotes or, alternatively, was it more similar to the ecdozoa and how RNAi may relate to disease control in aquaculture? RNAi in molluscs appears to have been only investigated in about 14 species, mostly as a gene silencing phenomenon. We can infer that microRNAs including let-7 are functional in molluscs. The genes/proteins involved in the actual RNAi pathways have only been rudimentarily investigated, so how homologous the genes and proteins are to other metazoa is unknown. Furthermore, how many different genes for each activity in the RNAi pathway are also unknown? The cephalopods have been greatly overlooked with only a single RNAi gene-silencing study found. The long dsRNA-linked interferon pathways seem to be present in molluscs, unlike some other invertebrates and could be used to reduce disease states in aquaculture. In particular, interferon regulatory factor genes have been found in molluscs of aquacultural importance such as Crassostrea, Mytilus, Pinctada and Haliotis. Two possible aquaculture scenarios are discussed, zoonotic norovirus and ostreid herpesvirus 1 to illustrate the possibilities. The entire field of RNAi in molluscs looks ripe for scientific exploitation and practical application.

  5. Agonistic behaviour in juvenile southern rock lobster, Jasus edwardsii (Decapoda, Palinuridae: implications for developing aquaculture

    Directory of Open Access Journals (Sweden)

    Chris Carter

    2014-11-01

    Full Text Available The Southern rock lobster, Jasus edwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasus edwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11, avoidance (6 and others (12. Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture.

  6. Agonistic behaviour in juvenile southern rock lobster, Jasusedwardsii (Decapoda, Palinuridae): implications for developing aquaculture.

    Science.gov (United States)

    Carter, Chris G; Westbury, Heath; Crear, Bradley; Simon, Cedric; Thomas, Craig

    2014-01-01

    The Southern rock lobster, Jasusedwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasusedwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11), avoidance (6) and others (12). Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture.

  7. Teleost microbiomes: progress towards their characterisation, manipulation and applications in aquaculture and fisheries.

    Directory of Open Access Journals (Sweden)

    Martin eLlewellyn

    2014-06-01

    Full Text Available Indigenous bacterial flora play a critical role in the lives of their vertebrate hosts. In human and mouse models it is increasingly clear that innate and adaptive immunity develop in close consort with the commensal microbiome. Furthermore several aspects of digestion and nutrient metabolism are governed by intestinal microflora. Research on teleosts has responded relatively slowly to the revolution in microbiomics. Nonetheless, progress has been made in biotic and gnotobiotic zebrafish models, defining a core microbiome and describing its role in development. However, microbiome research in other teleost species, especially those important from an aquaculture perspective, has been relatively slow. In this review, we examine progress in teleost microbiome research to date. We discuss teleost microbiomes in health and disease, microbiome ontogeny, prospects for successful microbiome manipulation (especially in an aquaculture setting and attempt to identify important future research themes. We predict an explosion in research in this sector in line with the increasing global demand for fish protein, and the need to find sustainable approaches to improve aquaculture yield. The reduced cost and increasing ease of next generation sequencing technologies provides the technological backing, and the next 10 years will be an exciting time for teleost microbiome research.

  8. Enrichment of bioactive compounds in microalgae for aquaculture

    OpenAIRE

    Fernandes, Tomásia Micaela Gomez

    2015-01-01

    Microalgae are promising microorganisms for the production of food and fine chemicals. Several species of microalgae are used in aquaculture with the purpose of transfer bioactive compounds up to the aquatic food chain. The main objective of this project was to develop a stress–inducement strategy in order to enhance the biochemical productivity of Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp. for aquaculture purposes having in account their growth and organizational differen...

  9. Green and technical efficient growth in Danish fresh water aquaculture

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2011-01-01

    Aquaculture is the fastest growing animal food processing sector in the world. Nevertheless, growth inside the Organization for Economic Co-operation and Development has been stagnating, with few exceptions. The main reason is strict environmental regulations. This study investigates if green...... growth can be achieved by introducing new environmentally friendly water purification systems in Danish fresh water aquaculture. Data Envelopment Analysis is used to investigate whether different water purification systems and farm size influence technical efficiency. The empirical results indicate...

  10. Key Performance Characteristics of Organic Shrimp Aquaculture in Southwest Bangladesh

    OpenAIRE

    Christian Reinhard Vogl; Brojo Gopal Paul

    2012-01-01

    In Bangladesh, black tiger shrimp (Penaeus monodon; Fabricius, 1798) aquaculture has come to be one of the most important sectors in both the rural and national economies. Likewise, organic shrimp aquaculture has emerged as an alternative farming enterprise for farmers especially in the southwestern districts of Bangladesh. The present study aims to show key performance characteristics of organic shrimp farmers and farming in a prototypical shrimp farming area in Banglade...

  11. Charting the Research Course for Sustainable Aquaculture in Sabah, Malaysia

    OpenAIRE

    Vun L. W.; Payus C. M.; Mohd Ali S. A.

    2016-01-01

    Due to arising needs and demands, aquaculture is currently the fastest growing food production sector. In order to increase yield and yet to remain sustainable, the challenges would be to minimise impact on the environment and ecosystem services. Aquaculture activity contributes significantly to Malaysia and also the state of Sabah’s economy and food security. Hence, the future changes in the environment as a result of rapid population growth and development would pose as threats to this indu...

  12. Interactions of Aquaculture and Waste Disposal in the Coastal Zone

    Institute of Scientific and Technical Information of China (English)

    ZHAI Xuemei; Hawkins S.J.

    2002-01-01

    Throughout the world, the coastal zones of many countries are used increasingly for aquaculture in addition to other activities such as waste disposal. These activities can cause environmental problems and health problems where they overlap. The interaction between aquaculture and waste disposal, and their relationship with eutrophication are the subjects of this paper.Sewage discharge without adequate dispersion can lead to nutrient elevation and hence eutrophication which has clearly negative effects on aquaculture with the potential for toxic blooms. Blooms may be either toxic or anoxia-causing through the decay process or simply clog the gills of filter-feeding animals in some cases. With the development of aquaculture, especially intensive aquaculture, many environmental problems appeared, and have resulted in eutrophication in some areas. Eutrophication may destroy the health of whole ecosystem which is important for sustainable aquaculture.Sewage discharge may also cause serious public health problems. Filter-feeding shellfish growing in sewage-polluted waters accumulate micro-organisms, including human pathogenic bacteria and viruses, and heavy metal ion, presenting a significant health risk. Some farmed animals may also accumulate heavy metals from sewage. Bivalves growing in areas affected by toxic algae blooms may accumulate toxins (such as PSP, DSP) which can be harmful to human beings.

  13. Use of sunlight to degrade oxytetracycline in marine aquaculture's waters.

    Science.gov (United States)

    Leal, J F; Esteves, V I; Santos, E B H

    2016-06-01

    Oxytracycline (OTC) is a broad spectrum antibiotic authorized for use in European aquaculture. Its photo-degradation has been widely studied in synthetic aqueous solutions, sometimes resorting to expensive methods and without proven effectiveness in natural waters. Thus, this work studied the possibility to apply the solar photo-degradation for removal of OTC from marine aquaculture's waters. For that, water samples were collected at different locals of the water treatment circuit, from two different aquaculture companies. Water samples were firstly characterized regarding to pH, salinity, total suspended solids (TSS), organic carbon and UV-Vis spectroscopic characteristics. Then, the samples were spiked with OTC and irradiated using simulated sunlight in order to evaluate the matrix effects on OTC photo-degradation. From kinetic results, the apparent quantum yields and the outdoor half-life times, at 40°N for midsummer and midwinter days were estimated by the first time for these conditions. For a midsummer day, at sea level, the outdoor half-life time predicted for OTC in these aquaculture's waters ranged between 21 and 25 min. Additionally, the pH and salinity effects on the OTC photo-degradation were evaluated and it has been shown that high pH values and the presence of sea salt increase the OTC photo-degradation rate in aquaculture's waters, compared to results in deionised water. The results are very promising to apply this low-cost methodology using the natural sunlight in aquaculture's waters to remove OTC.

  14. Impact of pond and fence aquaculture on reservoir environment

    Directory of Open Access Journals (Sweden)

    Huai-dong ZHOU

    2011-03-01

    Full Text Available With the rapid development of aquaculture in lakes and reservoirs, its negative effects on water quality and aquatic organisms are clearly emerging. Toward a better understanding of these effects, chemical and biological monitoring was conducted in the Fangbian Reservoir to study the relationship between aquaculture and eutrophication. As a domestic water supply source, this reservoir has reached the mesotrophic level. The concentrations of total nitrogen (TN and total phosphorus (TP in the Fangbian Reservoir have frequently exceeded the prescriptive level according to the Environmental Quality Standards for Surface Water (GB3838-2002. Pond and fence aquaculture feeding is the main cause of high levels of nitrogen and phosphorus, accounting for nearly half of the total pollution, and causing the reservoir environmental capacity to be exceeded. The amounts of nitrogen and phosphorus that went directly to the reservoir through the residual bait and fish droppings in fence aquaculture were 42 768 kg per year and 10 856 kg per year respectively, from 2007 to 2009. About 2 913 kg of nitrogen and 450 kg of phosphorus were imported to the reservoir through the exchange of water from the culturing ponds at the same time. Therefore, controlling the aquaculture scale and promoting eco-aquaculture are key measures for lessening the eutrophication degree and improving the water quality.

  15. Interactions of aquaculture and waste disposal in the coastal zone

    Science.gov (United States)

    Xuemei, Zhai; Hawkins, S. J.

    2002-04-01

    Throughout the world, the coastal zones of many countries are used increasingly for aquaculture in addition to other activities such as waste disposal. These activities can cause environmental problems and health problems where they overlap. The interaction between aquaculture and waste disposal, and their relationship with eutrophication are the subjects of this paper. Sewage discharge without adequate dispersion can lead to nutrient elevation and hence eutrophication which has clearly negative effects on aquaculture with the potential for toxic blooms. Blooms may be either toxic or anoxia-causing through the decay process or simply clog the gills of filter-feeding animals in some cases. With the development of aquaculture, especially intensive aquaculture, many environmental problems appeared, and have resulted in eutrophication in some areas. Eutrophication may destroy the health of whole ecosystem which is important for sustainable aquaculture. Sewage discharge may also cause serious public health problems. Filter-feeding shellfish growing in sewage-polluted waters accumulate micro-organims, including human pathogenic bacteria and viruses, and heavy metal ion, presenting a significant health risk. Some farmed animals may also accumulate heavy metals from sewage. Bivalves growing in areas affected by toxic algae blooms may accumulate toxins (such as PSP, DSP) which can be harmful to human beings.

  16. Reconstruction of Sound Source Pressures in an Enclosure Using the Phased Beam Tracing Method

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Ih, Jeong-Guon

    2009-01-01

    Source identification in an enclosure is not an easy task due to complicated wave interference and wall reflections, in particular, at mid-high frequencies. In this study, a phased beam tracing method was applied to the reconstruction of source pressures inside an enclosure at medium frequencies......-directional sphere and a cubic source in a rectangular enclosure were taken as examples in the simulation tests. A reconstruction error was investigated by Monte Carlo simulation in terms of field point locations. When the source information was reconstructed by the present method, it was shown that the sound power...

  17. The permanent total enclosure: A useful tool in pollution prevention and streamlined regulatory permitting

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, S.C. [Eckenfelder Inc., Greenville, SC (United States)

    1997-12-31

    In today`s competitive work environment it is becoming increasingly important for industry to comply with environmental regulations and standards while minimizing cost on pollution control systems. This often requires innovative new solutions to existing environmental challenges. Strategic environmental planning and process optimization are key elements in cost-effective environmental management. The permanent total enclosure can be a useful tool in the strategic environmental planning process. This paper discusses the installation of a permanent total enclosure at a southeastern printing and publishing industry. By constructing the total enclosure the industry was able to streamline the permitting process and reduce pollutant emissions while simultaneously reducing cost and saving money.

  18. Construction and validation of a systematic ethogram of Macaca fascicularis in a free enclosure.

    Science.gov (United States)

    Xu, Fan; Xie, Liang; Li, Xin; Li, Qi; Wang, Tao; Ji, Yongjia; Kong, Fei; Zhan, Qunlin; Cheng, Ke; Fang, Liang; Xie, Peng

    2012-01-01

    Behavioral studies in non-human primates have become ideal models for further investigations into advanced cognitive function in humans. To date, there is no systematic ethogram of the cynomolgus monkey (Macaca fascicularis) in a free enclosure. In a field observation of 6012 subjects, 107 distinct behaviors of M. fascicularis were preliminarily described. 83 of these behaviors were then independently validated through a randomized cohort and classified into 12 behavioral categories. 53 of these behaviors were then selected to accurately reflect the daily mundane activity of the species in a free enclosure. These findings systematically document the behavior of M. fascicularis in a free enclosure for use in further investigations.

  19. Construction and validation of a systematic ethogram of Macaca fascicularis in a free enclosure.

    Directory of Open Access Journals (Sweden)

    Fan Xu

    Full Text Available Behavioral studies in non-human primates have become ideal models for further investigations into advanced cognitive function in humans. To date, there is no systematic ethogram of the cynomolgus monkey (Macaca fascicularis in a free enclosure. In a field observation of 6012 subjects, 107 distinct behaviors of M. fascicularis were preliminarily described. 83 of these behaviors were then independently validated through a randomized cohort and classified into 12 behavioral categories. 53 of these behaviors were then selected to accurately reflect the daily mundane activity of the species in a free enclosure. These findings systematically document the behavior of M. fascicularis in a free enclosure for use in further investigations.

  20. Assessment of surface and groundwater quality for use in aquaculture in parts of northern Nigeria

    Directory of Open Access Journals (Sweden)

    S. A. Arabi,

    2011-08-01

    Full Text Available In recent times, fish farming (aquaculture has become a major source of income and a substitute for beef in many homes all over Nigeria because a kilogram of fish is cheaper especially the so call ice-fish compare to same kilogram of beef. As a result, many people have embraced fish farming and while some aquaculturist have recorded loss, only few got it right especially at the initial stage of the fish farming business. Some fish farm had average fish weighing a kilogram while others have average weighing less than half a kilogram due to many factors ranging from contamination of pond water from pile up of feeding stuff at bottom of the pond to the use of ground or surface water whose constituents or chemically controlled parameters have adverse effects on harvest in aquaculture. This study was carried out to ascertain the worth or not of surface and groundwater from parts of northern Nigeria for fish farming. Thirty seven surface and groundwater samples were collected during the peak of dry season and analyzed for physicochemical parameter, major and minor elements that can have adverse effects on fish farming using model V-2000 multi-analyte photometer, atomic absorption spectrophotometer, pH and conductivity meter. Some of the measurements were carried out in-situ, while others were carried out in the laboratory. Most of the samples (92% analyzed indicate that they can be used efficiently for aquaculture, only few were observed to have some adverse effects on the intended use and these include pH, salinity, sodium contents and residual sodium carbonate which are closely related to the pH of water samples analyzed. It can be summarized that the studied water samples are generally good for aquaculture.

  1. MANAGEMENT OF SUSTAINABLE SEAWEED (Kappaphycus alvarezii AQUACULTURE IN THE CONTEXT OF CLIMATE CHANGE MITIGATION

    Directory of Open Access Journals (Sweden)

    Erlania Erlania

    2014-06-01

    Full Text Available Seaweed is an important aquaculture commodity that could contribute on climate change mitigation, related to its ability on absorbing CO2, as one of the green house gases, through photosynthesis. This study aimed to analyze seaweed potencies on carbon sequestration in the context of climate change mitigation while still resulting optimum production as primary purpose and to analyze the carrying capacity of Gerupuk Bay in order to manage sustainability of seaweed aquaculture. Seaweed, (Kappaphycus alvarezii was cultivated with long-line system in Gerupuk Bay, West Nusa Tenggara, during five months for three cultivation cycles. Samplings were conducted at days-15, 30, and 45 with CO2 absorption rates as main parameters. Water carrying capacity was calculated to determine the ability of Gerupuk Bay waters for supporting development of sustainable seaweed aquaculture. The results showed that absorption rates of CO2 by seaweed (K. alvarezii were different at each sampling days of cultivation periods; the highest value was at 10-20 days of cultivation. CO2 absorption analysis resulted based on sampling days of cultivation period could be appl ied to formulate the strategies for management of sustainable seaweed aquaculture, with optimal production and positively contributed to the environment. However, waters carrying capacity should also be considered as major aspect in the application of seaweed cultivation management, thus it can run continuously without causing conflicts with other interests.

  2. Toxicity of three antibiotics used in aquaculture on the marine microalgae Tetraselmis suecica (Kylin Butch.

    Directory of Open Access Journals (Sweden)

    Marta Seoane

    2014-06-01

    Full Text Available Aquaculture facilities are a potential source of antibiotics to the aquatic ecosystems. The presence of these compounds in the environment may have deleterious effects on non-target aquatic organisms such as microalgae, which are often used as biological indicators of pollution. Therefore, the aim of the present study was to evaluate the toxicity induced by chloramphenicol (CHL, florfenicol (FLO and oxytetracycline (OTC, three antibiotics widely used in aquaculture, on the marine microalgae Tetraselmis suecica, a species also used in aquacultural practices. Toxicity was evaluated taking into account alterations on growth and cellular viability and activity, being these parameters monitored using flow cytometry technique. Results showed that all three antibiotics assayed inhibit growth of T. suecica with 96 h IC50 values of 11.16, 9.03 and 17.25 mg l-1 for CHL, FLO and OTC, respectively. After 24 hours of exposure, the integrity of the cell membrane, related with cellular viability and assessed by propidium iodide staining (PI, was not altered; therefore cells remained viable. However, FLO and OTC were found to significant reduce the metabolic activity at higher concentrations assayed, as indicated the fluorescein diacetate assay (FDA. Since growth inhibition and significant physiological alterations were observed, it can be concluded that T. suecica was sensitive to the three antibiotics tested, thus the use of these antibiotics should be carefully monitored to reduce the potential risk of contamination of the marine environment.

  3. Oxygen ingress study of 3D printed gaseous radiation detector enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Steer, Christopher A.; Durose, Aaron [AWE, Alderrnaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2015-07-01

    As part of our ongoing studies into the potential application of 3D printing techniques to gaseous radiation detectors, we have studied the ability of 3D printed enclosures to resist environmental oxygen ingress. A set of cuboid and hexagonal prism shaped enclosures with wall thicknesses of 4 mm, 6 mm, 8 mm and 10 mm were designed and printed in nylon using a EOSINT P 730 Selective Laser Sintering 3D printer system These test enclosures provide a comparison of different environmental gas ingress for different 3D printing techniques. The rate of change of oxygen concentration was found to be linear, decreasing as the wall thickness increases. It was also found that the hexagonal prism geometry produced a lower rate of change of oxygen concentration compared with the cuboid shaped enclosures. Possible reasons as to why these results were obtained are discussed The implications for the this study for deployable systems are also discussed (authors)

  4. Enhancement of natural ventilation in rectangular enclosure with two openings by thin fin

    Institute of Scientific and Technical Information of China (English)

    YANG Yi; DENG Qi-hong

    2005-01-01

    A numerical method was used to study the natural ventilation in a rectangular enclosure with two symmetrical openings. In order to improve the natural ventilation efficiency, a fin was introduced into the enclosure.Steady-state heat transfer by laminar natural ventilation in a partially divided rectangular enclosure was investigated by numerically solving equations of mass, momentum and energy. Streamlines and isotherms were produced and heat transfer rate were calculated. A parametric study was carried out using the following parameters: Rayleigh number (1 × 103 - 1 × 106) , dimensionless length (0 - 0.7) and position values (-0. 7 - 0. 7). It is found that the Nusselt number is an increasing function of Rayleigh number. By comparing with no-fin case, it is concluded that fin can effectively enhance the natural ventilation in the enclosure.

  5. Liquid-mixed convection in a closed enclosure with highly-intensive heat fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Rivas-Cardona, A.; Hernandez-Guerrero, A. [Universidad de Guanajuato, Facultad de Ingenieria Mecanica, Electrica y Electronica, Salamanca, Guanajuato (Mexico); Romero-Mendez, R. [Universidad Autonoma de San Luis Potosi, Facultad de Ingenieria, San Luis Potosi (Mexico); Lesso-Arroyo, R. [Instituto Tecnologico de Celaya, Dept. de Ingenieria Mecanica, Celaya Gto. (Mexico)

    2004-09-01

    Laminar-mixed convection of a dielectric fluid contained in a two-dimensional enclosure is investigated in the present paper. Within the enclosure discrete heat sources of a constant heat flux are flush-mounted on a vertical wall. Forced flow conditions are imposed by placing a propeller at different locations within the enclosure. The analysis is performed for a wide range of heat fluxes, from the order of 10,000 to 100,000 W/m{sup 2}, way in the trend of current computer chips, such as the Pentium IV, and the future ones. Emphasis is placed on the influence of the governing parameters, such as buoyancy parameters, the aspect ratio of the enclosure, and location of the propeller. The flow and temperature fields are obtained as part of the solution. (Author)

  6. Aquaculture genomics, genetics and breeding in the United States: Current status, challenges, and priorities for future research

    Science.gov (United States)

    Advancing the production efficiency and profitability of aquaculture is dependent upon the ability to utilize a diverse array of genetic resources. The ultimate goals of aquaculture genomics, genetics and breeding research are to enhance aquaculture production efficiency, sustainability, product qua...

  7. Numerical simulation of natural convection in a differentially heated tall enclosure using a spectral element method

    OpenAIRE

    Pitz, DB; Chew, JW

    2015-01-01

    Natural convection in differentially heated enclosures is a benchmark problem used to investigate the physics of buoyant flows and to validate numerical methods. Such configurations are also of interest in engineering applications such as cooling of electronic components and air flow around buildings. In this work a spectral element method is used to carry out direct numerical simulations of natural convection in a tall enclosure of aspect ratio 4 with isothermal vertical walls and adiabatic ...

  8. Laying hen movement in a commercial aviary: Enclosure to floor and back again.

    Science.gov (United States)

    Campbell, D L M; Makagon, M M; Swanson, J C; Siegford, J M

    2016-01-01

    Many producers in the laying hen industry, including in North America, are phasing out conventional cages in response to consumer demands and sometimes subsequent legislation. Alternative housing systems such as aviaries are being implemented in an attempt to improve hen welfare. Aviaries provide additional space and resources to groups of hens, including a litter area on the floor. However, little is known about hen movement between tiered enclosures and floor litter areas in aviary systems. Diurnal rhythms and social attraction may result in peak times of movement that could lead to overcrowding of areas, or alternatively hen preferences may lead to some areas not being fully utilized. We monitored hen movement between tiered enclosures and litter areas, including movement on and off the outer perch, across the day at peak, mid and end of lay in a commercial aviary. Hens moved onto and off of the open litter area across the day, transitioning between tiered enclosures, outer perches, open litter areas, and litter areas under tiered enclosures. At certain times of day, there were periods of greater hen movement down to the open litter area and between litter areas. For example, more hens were typically observed exiting enclosures, jumping from perches to open litter, and traveling between open litter and litter under tiered enclosures in the morning (all P ≤ 0.001). In all but one instance, more hens were observed on open litter areas in the afternoon than at other times of day (all P ≤ 0.029). However, hen re-entry to tiered enclosures showed less circadian patterning. Hen movement was observed between areas of interest at all sampled time periods, indicating hens use all areas of the system. Further research should examine whether all individual hens do move between areas equally, including within levels of the tiered enclosure, or if crowding occurs on the outer perches or in the litter during times of peak movement.

  9. Discussion on the Network Method for Calculating Radiant Interchange Within an Enclosure

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    In this paper the Δ-Y transformation of a linear electric circuit is introduced to simplify the computation of net radiant heat exchange on a surface of an enclosure with three surfaces.The illustration of the transformation is given by solving six problems taken from the textbooks.Some discussion concerning the possibility of extending the transformation method to enclosures with more than three surfaces,and the condition for applying the network method are also presented.

  10. Numerical Simulation of Natural Convection of a Nanofluid in an Inclined Heated Enclosure Using Two-Phase Lattice Boltzmann Method: Accurate Effects of Thermophoresis and Brownian Forces

    OpenAIRE

    Ahmed, Mahmoud; Eslamian, Morteza

    2015-01-01

    Laminar natural convection in differentially heated (β = 0°, where β is the inclination angle), inclined (β = 30° and 60°), and bottom-heated (β = 90°) square enclosures filled with a nanofluid is investigated, using a two-phase lattice Boltzmann simulation approach. The effects of the inclination angle on Nu number and convection heat transfer coefficient are studied. The effects of thermophoresis and Brownian forces which create a relative drift or slip velocity between the particles and th...

  11. Persistence and distribution of 4-nonylphenol in water, sediment, macrophytes, and wall material of littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Heinis, L.J.; Tunell, R.; Liber, K. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Knuth, M.L. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1994-12-31

    Eighteen enclosures (5 m x 10 m) were constructed in the littoral zone of a 2-ha pond near Duluth, MN. Each enclosure consisted of 5 m of natural shoreline and three walls of an inert plastic. The enclosures had an average surface area of 31.9 m{sup 2} , an average depth of 0.6 m and an average water volume of 33.1 m{sup 3}. The enclosure waters were treated with the alkyl phenol ethoxylate precursor and degradation product 4-nonylphenol. Application was accomplished by sub-surface injection over a 20-day period with a 2 day frequency. Nominal aqueous concentrations were 0, 3, 30, 100 and 300 {mu}g/L. Concentrations of 4-nonylphenol were monitored during and after application in the water, sediment, macrophytes, and enclosure wall material. Average maximum water concentrations ranged from 96.5% of nominal to 62.0% of nominal and average minimum water concentrations ranged from 33.3% of nominal to 29.5% of nominal during the application period. Water concentrations decreased exponentially after application ended. Sediment concentrations during the application period were constant from 8 to 20 d and peak concentrations occurred 48 d after application began. Macrophyte concentrations peaked 21 d after initial application with a steady decline through 76 d. Enclosure wall material concentrations reached a peak 3 h before the final application. A gradual decline occurred until 34 d after initial application followed by a more rapid dissipation.

  12. Modeling Enclosure Design in Above-Grade Walls

    Energy Technology Data Exchange (ETDEWEB)

    Lstiburek, J. [Building Science Corporation, Westford, MA (United States); Ueno, K. [Building Science Corporation, Westford, MA (United States); Musunuru, S. [Building Science Corporation, Westford, MA (United States)

    2016-03-01

    This report describes the modeling of typical wall assemblies that have performed well historically in various climate zones. The WUFI (Warme und Feuchte instationar) software (Version 5.3) model was used. A library of input data and results are provided. The provided information can be generalized for application to a broad population of houses, within the limits of existing experience. The WUFI software model was calibrated or tuned using wall assemblies with historically successful performance. The primary performance criteria or failure criteria establishing historic performance was moisture content of the exterior sheathing. The primary tuning parameters (simulation inputs) were airflow and specifying appropriate material properties. Rational hygric loads were established based on experience - specifically rain wetting and interior moisture (RH levels). The tuning parameters were limited or bounded by published data or experience. The WUFI templates provided with this report supply useful information resources to new or less-experienced users. The files present various custom settings that will help avoid results that will require overly conservative enclosure assemblies. Overall, better material data, consistent initial assumptions, and consistent inputs among practitioners will improve the quality of WUFI modeling, and improve the level of sophistication in the field.

  13. NUMERICAL ANALYSIS OF NATURAL CONVECTION IN A PRISMATIC ENCLOSURE

    Directory of Open Access Journals (Sweden)

    Walid AICH

    2011-01-01

    Full Text Available Natural convection heat transfer and fluid flow have been examined numerically using the control-volume finite-element method in an isosceles prismatic cavity, submitted to a uniform heat flux from below when inclined sides are maintained isothermal and vertical walls are assumed to be perfect thermal insulators, without symmetry assumptions for the flow structure. The aim of the study is to examine a pitchfork bifurcation occurrence. Governing parameters on heat transfer and flow fields are the Rayleigh number and the aspect ratio of the enclosure. It has been found that the heated wall is not isothermal and the flow structure is sensitive to the aspect ratio. It is also found that heat transfer increases with increasing of Rayleigh number and decreases with increasing aspect ratio. The effects of aspect ratio become significant especially for higher values of Rayleigh number. Eventually the obtained results show that a pitchfork bifurcation occurs at a critical Rayleigh number, above which the symmetric solutions becomes unstable and asymmetric solutions are instead obtained.

  14. Thiohalocapsa marina sp. nov., from an Indian marine aquaculture pond.

    Science.gov (United States)

    Anil Kumar, P; Srinivas, T N R; Thiel, V; Tank, M; Sasikala, Ch; Ramana, Ch V; Imhoff, J F

    2009-09-01

    A spherical-shaped, phototrophic, purple sulfur bacterium was isolated in pure culture from anoxic sediment in a marine aquaculture pond near Bheemli (India). Strain JA142T is Gram-negative and non-motile. It has a requirement for NaCl (optimum of 2% and maximum of 6% w/v NaCl). Intracellular photosynthetic membranes are of the vesicular type. In vivo absorption spectra indicate the presence of bacteriochlorophyll a and carotenoids of the okenone series as photosynthetic pigments. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA142T is related to halophilic purple sulfur bacteria of the genera Thiohalocapsa and Halochromatium, with the highest sequence similarity to Thiohalocapsa halophila DSM 6210T (97.5%). Morphological and physiological characteristics differentiate strain JA142T from other species of the genera Halochromatium and Thiohalocapsa. Strain JA142T is sufficiently different from Thiohalocapsa halophila based on 16S rRNA gene sequence analysis and morphological and physiological characteristics to allow the proposal of a novel species, Thiohalocapsa marina sp. nov., with the type strain JA142T (=JCM 14780T=DSM 19078T).

  15. Hydroyeast Aquaculture® as a reproductive enhancer agent for the adult Nile tilapia (Oreochromis niloticus Linnaeus, 1758).

    Science.gov (United States)

    Mehrim, Ahmed I; Khalil, Fathy F; Hassan, Montaha E

    2015-04-01

    Tilapias are becoming increasingly popular culture fish because of their superior culture adaptability. In recent years, there has been a great interest in the use of probiotics in fish aquaculture. The objectives of the present study were to evaluate the effect of dietary graded levels (0, 5, 10, and 15 g/kg commercial diet, referred to treatments numbers T1, T2, T3, and T4, for males and T5, T6, T7, and T8 treatments for females) of a new probiotic Hydroyeast Aquaculture(®) on hematological and biochemical parameters, serum sex hormones, and the reproductive efficiency parameters of the adult Nile tilapia Oreochromis niloticus for 8 weeks. Results revealed that high levels of probiotics diet, 15 g (T4, ♂) and 10 g (T7, ♀) probiotic/kg diet, significantly (P ≤ 0.05) enhanced the physiological responses (hematological as well as serum biochemical parameters) together with, reproductive performances (sex hormones, testes and sperm quality parameters, absolute and relative fecundity, and ovarian measurements). Therefore, it could be conclude that Hydroyeast Aquaculture(®) is useful at levels of 15 g (T4) and 10 g (T7)/kg diet in improving the reproductive efficiency of adult O. niloticus males and females, respectively. Thus, the use of Hydroyeast Aquaculture(®) may be economically important for fish hatcheries.

  16. Potential use of power plant reject heat in commercial aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10/sup 5/ kg/year of fish, 1.5 x 10/sup 6/ kg/year of clam meat, and 1.5 x 10/sup 4/ kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated.

  17. Responsible aquaculture in 2050: Valuing local conditions and human innovations will be key to success

    NARCIS (Netherlands)

    Diana, J.S.; Egna, H.S.; Chopin, T.; Peterson, M.S.; Cao, L.; Pomeroy, R.; Verdegem, M.C.J.; Slack, W.T.; Bondad-Reantaso, M.G.; Cabello, F.

    2013-01-01

    As aquaculture production expands, we must avoid mistakes made during increasing intensification of agriculture. Understanding environmental impacts and measures to mitigate them is important for designing responsible aquaculture production systems. There are four realistic goals that can make futur

  18. Genetic evidence for the uncoupling of local aquaculture activities and a population of an invasive species--a case study of Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Kochmann, Judith; Carlsson, Jens; Crowe, Tasman P; Mariani, Stefano

    2012-01-01

    Human-mediated introduction of nonnative species into coastal areas via aquaculture is one of the main pathways that can lead to biological invasions. To develop strategies to counteract invasions, it is critical to determine whether populations establishing in the wild are self-sustaining or based on repeated introductions. Invasions by the Pacific oyster (Crassostrea gigas) have been associated with the growing oyster aquaculture industry worldwide. In this study, temporal genetic variability of farmed and wild oysters from the largest enclosed bay in Ireland was assessed to reconstruct the recent biological history of the feral populations using 7 anonymous microsatellites and 7 microsatellites linked to expressed sequence tags (ESTs). There was no evidence of EST-linked markers showing footprints of selection. Allelic richness was higher in feral than in aquaculture samples (P = 0.003, paired t-test). Significant deviations from Hardy-Weinberg equilibrium due to heterozygote deficiencies were detected for almost all loci and samples, most likely explained by the presence of null alleles. Relatively high genetic differentiation was found between aquaculture and feral oysters (largest pairwise multilocus F(ST) 0.074, P aquaculture (largest pairwise multilocus F(ST) 0.073, P aquaculture and wild samples using Bayesian clustering approaches. A 10-fold higher effective population size (N(e)) and a high number of private alleles in wild oysters suggest an established self-sustaining feral population. The wild oyster population studied appears demographically independent from the current aquaculture activities in the estuary and alternative scenarios of introduction pathways are discussed.

  19. An overview: biomolecules from microalgae for animal feed and aquaculture.

    Science.gov (United States)

    Yaakob, Zahira; Ali, Ehsan; Zainal, Afifi; Mohamad, Masita; Takriff, Mohd Sobri

    2014-12-01

    Despite being more popular for biofuel, microalgae have gained a lot of attention as a source of biomolecules and biomass for feed purposes. Algae farming can be established using land as well as sea and strategies can be designed in order to gain the products of specific interest in the optimal way. A general overview of the contributions of Algae to meet the requirements of nutrients in animal/aquaculture feed is presented in this study. In addition to its applications in animal/aquaculture feed, algae can produce a number of biomolecules including astaxanthin, lutein, beta-carotene, chlorophyll, phycobiliprotein, Polyunsaturated Fatty Acids (PUFAs), beta-1,3-glucan, and pharmaceutical and nutraceutical compounds which have been reviewed with respect to their commercial importance and current status. The review is further extended to highlight the adequate utilization of value added products in the feeds for livestock, poultry and aquaculture (with emphasis in shrimp farming).

  20. Taking account of fish welfare: lessons from aquaculture.

    Science.gov (United States)

    Huntingford, F A; Kadri, S

    2009-12-01

    This paper explores the possibility that lessons learned from aquaculture might contribute to current debate on welfare and fisheries. After looking briefly at the history of research interest in the welfare of farmed fishes, some implications of using different definitions of and approaches to the concept of welfare are discussed. Consideration is given to the way in which the aquaculture industry has responded to public concern about fish welfare and, for cases where these responses have been effective, why this might be the case. Finally, possible cross-over points between aquaculture and fisheries in the context of fish welfare, as well as experience and expertise that might be shared between these two areas, are identified.

  1. Microbial populations causing off-flavour in recirculated aquaculture systems

    DEFF Research Database (Denmark)

    Lukassen, Mie Bech; Nielsen, Jeppe Lund; Schramm, Edward

    Microbial production of geosmin, a secondary metabolite with an earthy off-flavour is a serious economic problem in wine production, drinking water and aquaculture. Geosmin is produced by a small group of bacteria all harboring the geosmin synthetase gene (geoA). Sequencing and analyzing the dist......Microbial production of geosmin, a secondary metabolite with an earthy off-flavour is a serious economic problem in wine production, drinking water and aquaculture. Geosmin is produced by a small group of bacteria all harboring the geosmin synthetase gene (geoA). Sequencing and analyzing...... and activity. These findings are useful for the future optimization and management of full-scale aquaculture plants, and can be used as a diagnostic tool in developing strategies to limit the presence and growth of geosmin-producing bacteria....

  2. Human Health Consequences of Use of Antimicrobial Agents in Aquaculture

    DEFF Research Database (Denmark)

    Heuer, Ole Eske; Kruse, H.; Grave, K.

    2009-01-01

    industry in many regions of the world and the widespread, intensive, and often unregulated use of antimicrobial agents in this area of animal production, efforts are needed to prevent development and spread of antimicrobial resistance in aquaculture to reduce the risk to human health.......Intensive use of antimicrobial agents in aquaculture provides a selective pressure creating reservoirs of drug-resistant bacteria and transferable resistance genes in fish pathogens and other bacteria in the aquatic environment. From these reservoirs, resistance genes may disseminate by horizontal...... gene transfer and reach human pathogens, or drug-resistant pathogens from the aquatic environment may reach humans directly. Horizontal gene transfer may occur in the aquaculture environment, in the food chain, or in the human intestinal tract. Among the antimicrobial agents commonly used...

  3. Aquaculture Asia, Vol. 7, No. 3, pp.1-60, July - September 2002

    OpenAIRE

    2002-01-01

    CONTENTS: Sustainable Aquaculture - Peter Edwards writes on rural aquaculture: Aquaculture for Poverty Alleviation and Food Security - Part II. Shrimp pond waste management by U Win Latt. The role of rural extension in the sustainable development of Chinese aquaculture by Min Kuanhong. Farmers as Scientists: Diversity enhances profitability and sustainability by M.C. Nandeesha. Properties of Liming Materials by Claude E. Boyd, Mali Boonyaratpalin & Taworn Thunjai. Seed Produc...

  4. The impacts of green building strategies on the durability and performance of building enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, P. [RDH Building Engineering Ltd., Vancouver, BC (Canada)

    2007-07-01

    All buildings experience some level of failure during their lifetime. As such, it is to be expected that green buildings are likely to experience the same range of durability and building enclosure problems that affect conventional buildings, unless specific measures are taken. The author emphasized that when durability problems are identified in a green building, it is important to fully understand into which category the problems fall. This study used the Leadership in Energy and Environmental Design (LEED) rating system as a comparison framework for evaluating the environmental impact of green design strategies. LEED was also the focus of the study because of concerns that the processes involved in achieving LEED certification may themselves have negative impacts. Each of the following performance categories was reviewed in this paper: sustainable sites; water efficiency; energy and atmosphere; materials and resources; and, indoor environmental quality. The recommended design strategies to achieve each credit were also identified. It was concluded that the main problem in investigating durability issues in relation to green buildings is that so many of the buildings are new and relatively untested. The performance of these buildings will only become apparent over time. As such, ongoing monitoring and verification of performance is needed. 7 refs., 2 tabs., 1 fig.

  5. Assessment of a closed greenhouse aquaculture and hydroponic system

    Energy Technology Data Exchange (ETDEWEB)

    Head, W.D.

    1984-01-01

    Research was conducted to address three objectives: 1) to determine the nitrogen cycling of a closed greenhouse aquaculture and hydroponic system; 2) to determine the energy budget of a closed greenhouse aquaculture and hydroponic system; and 3) to determine which low cost fish diets could be used as a replacement or supplement to commercial diets for Tilapia mossambica. A 6435 liter recirculating aquaculture system was enclosed in a 32.6 m/sup 2/ greenhouse. Water was recirculated through two 416 liter trickling filter towers and three 5.5 m long hydroponic troughs. The aquaculture tank was stocked with a polyculture of channel catfish (Ictalurus punctatus) and tilapia (Tilapia mossambica) and the hydroponic troughs were planted with tomatoes (Lycopersicon esculentum). The fishes were fed a commercial fish diet and the tomatoes were irrigated with the aquaculture water using a modified Nutrient Film Technique. The fish yield was 42.2 kg and the average tomato yield from 24 plants was 4.1 kg/plant. The combined fish and tomato production accounted for 65% of the total nitrogen input. Leaf analyses and visual inspection showed that the tomato plants from the hydroponic troughs were deficient in potassium and magnesium. An energy analysis of the greenhouse and aquaculture-hydroponic system showed that when combining the energy outputs of heat, fish, and tomatoes the energy ratio (energy output/energy input) was similar to literature values for milkfish pond culture. When only the fish production was considered the energy ratio was similar to literature values reported for intensive water recirculating systems.

  6. Phylogeny of the Viral Hemorrhagic Septicemia Virus in European Aquaculture

    DEFF Research Database (Denmark)

    Cieslak, Michael; Mikkelsen, Susie Sommer; Skall, Helle Frank;

    2016-01-01

    One of the most valuable aquaculture fish in Europe is the rainbow trout, Oncorhynchus mykiss, but the profitability of trout production is threatened by a highly lethal infectious disease, viral hemorrhagic septicemia (VHS), caused by the VHS virus (VHSV). For the past few decades, the subgenogr......One of the most valuable aquaculture fish in Europe is the rainbow trout, Oncorhynchus mykiss, but the profitability of trout production is threatened by a highly lethal infectious disease, viral hemorrhagic septicemia (VHS), caused by the VHS virus (VHSV). For the past few decades...

  7. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (carbon dioxide removal.

  8. Eradication of viral haemorrhagic septicaemia in Danish aquaculture

    DEFF Research Database (Denmark)

    Olesen, Niels Jørgen; Skall, Helle Frank; Jensen, Britt Bang

    Eradication of viral haemorrhagic septicaemia in Danish aquaculture Olesen N.J.1, Skall H.F.1, Jensen B.B.2, Henriksen N.H.3, Mellergård S.4, H. Korsholm H.5 1National Veterinary Institute, Technical University of Denmark, Aarhus, Denmark 2Norwegian Veterinary Institute, Oslo, Norway 3Danish...... Aquaculture Association, Silkeborg, Denmark 4Danish Veterinary and Food Administration, Glostrup, Denmark 5Danish Veterinary and Food Administration, Vejle, Denmark Viral haemorrhagic septicaemia (VHS) virus was first isolated in Denmark in 1962, when more than half of the approximately 800 Danish fish farms...

  9. 77 FR 50082 - Notice of Opportunity To Submit Content Request for the 2013 Census of Aquaculture

    Science.gov (United States)

    2012-08-20

    ... Census of Aquaculture AGENCY: National Agricultural Statistics Service, Department of Agriculture. ACTION... currently accepting stakeholder feedback in the form of content requests for the 2013 Census of Aquaculture..., (202) 720-4333. SUPPLEMENTARY INFORMATION: The results of the 2005 Census of Aquaculture were...

  10. 50 CFR 21.47 - Depredation order for double-crested cormorants at aquaculture facilities.

    Science.gov (United States)

    2010-10-01

    ... cormorants at aquaculture facilities. 21.47 Section 21.47 Wildlife and Fisheries UNITED STATES FISH AND... aquaculture facilities. (a) What is the purpose of this depredation order? The purpose of this depredation...? This depredation order applies to commercial freshwater aquaculture facilities and to State and...

  11. Research update for the Harry K. Dupree Stuttgart National Aquaculture Research Center

    Science.gov (United States)

    Aquaculture (fish farming) has played an ever-increasing role in providing people with fish, shrimp, and shellfish. Aquaculture is currently the fastest growing sector of global food production and in 2014 totaled 80 million tons valued at $140 billion. The production of food-fish from aquaculture h...

  12. Contrasting effects of nitrogenous pollution on fitness and swimming performance of Iberian waterfrog, Pelophylax perezi (Seoane, 1885), larvae in mesocosms and field enclosures.

    Science.gov (United States)

    Egea-Serrano, A; Tejedo, M

    2014-01-01

    Amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. To understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. However, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. Further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified laboratory settings. Given the complexity of natural systems, determining whether amphibian responses in laboratory studies can be generalized to more realistic natural scenarios is critical. Towards this goal, this study assessed the impact of nitrogenous pollution on survival and fitness-related larval traits (growth, mass and swimming performance) for three populations of the frog Pelophylax perezi, exposed to different degrees of eutrophication in two different and complementary experiments: (1) pond mesocosms, with NH4Cl isolated or combined with NaNO2 and NaNO3, and (2) field enclosures placed in natural streams differing in their degree of pollution. For both mesocosm and field enclosure experiments, larval mortality was unaffected by nitrogenous pollution. However, in the mesocosm experiment, exposure to nitrogenous compounds reduced final larvae mass and growth. In contrast, in the enclosure experiment, polluted locations facilitated final mass and growth of surviving tadpoles. Population-level variation in the effect of pollution was observed for final larval mass in the mesocosm but not in the field enclosure experiment. In addition, although nitrogenous compounds in both mesocosm and natural conditions had no direct effect on absolute larval swimming performance, they may impact the viability of larvae by affecting the relationships between growth and the swimming abilities. The differential pattern found in the impacts of nitrogenous compounds on larvae of P. perezi

  13. The effects of varied densities on the growth and emigration of adult cutthroat trout and brook trout in fenced stream enclosures

    Science.gov (United States)

    Buys, D.J.; Hilderbrand, R.H.; Kershner, J.L.

    2009-01-01

    We evaluated the effects of various density treatments on adult fish growth and emigration rates between Bonneville cutthroat trout Oncorhynchus clarki utah and brook trout Salvelinus fontinalis in stream enclosures in Beaver Creek, Idaho, We used 3 density treatments (low, ambient, and high fish densities) to evaluate density-related effects and to ensure a response. Intraspecific ambient-density tests using cutthroat trout only were also performed. Results indicated an absence of cage effects in the stream enclosures and no differences in fish growth between ambient-density stream-enclosure fish and free-range fish. Brook trout outgrew and moved less than cutthroat trout in the stream enclosures, especially as density increased, In all 3 density treatments, brook trout gained more weight than cutthroat trout, with brook trout gaining weight in each density treatment and cutthroat trout losing weight at the highest density. At high densities, cutthroat trout attempted to emigrate more frequently than brook trout in sympatry and allopatry. We observed a negative correlation between growth and emigration for interspecific cutthroat trout, indicating a possible competitive response due to the presence of brook trout. We observed similar responses for weight and emigration in trials of allopatric cutthroat trout, indicating strong intraspecific effects as density increased. While cutthroat trout showed a response to experimental manipulation with brook trout at different densities, there has been long-term coexistence between these species in Beaver Creek, This system presents a unique opportunity to study the mechanisms that lead cutthroat trout to coexist with rather than be replaced by nonnative brook trout.

  14. Use of fish species from different trophic levels to control algae and water quality: An enclosure experiment in eutrophic area of Xiaojiang River

    Science.gov (United States)

    Pan, Xiaojie; Zhao, Na; Peng, Jianhua; Wan, Chengyan

    2017-01-01

    The effects of stocking both filter-feeding fish and piscivorous fish were compared to the effects of stocking only filter-feeding fish for suppressing algal blooms and improving water quality in the impoundment area of Xiaojiang River where catfish were dominant. Using only filter-feeding fish for algal suppression and water quality control was more effective in the short-term, but use of both filter-feeding fish and piscivorous fish was better in the long-term. Obvious suppression of phytoplankton biomass (PB) only occurred during the first 14 days regardless of the fish stocked. Adding fish to the enclosure clearly alters phytoplankton community structure and introducing piscivorous fish to an enclosure stocked with filter-feeding fish changed the relative densities of dominant algae species. While stocking filter-feeding fish decreased total nitrogen concentration by removing phytoplankton, it did not effectively decrease total phosphorus and Chlorophyll a concentrations. Introducing piscivorous fish to the enclosure weakened the relationship between nutrients and phytoplankton. Results indicate that stocking only filter-feeding fish to improve water quality and suppress phytoplankton in an impoundment area is insufficient and other technologies and means should be applied simultaneously. PMID:28273091

  15. Use of hydrodynamic and benthic models for managing environmental impacts of marine aquaculture

    DEFF Research Database (Denmark)

    Henderson, A.; Gamito, S.; Karakassis, I.

    2001-01-01

    Regulation to minimize impacts from aquaculture is of key concern in coastal zone management for the sustainability of the industry and the receiving environment. Market and consumer forces are presently driving much of this regulation and its implementation, Mathematical modelling can provide...... capacity or exploitation capacity in relation to nutrients and medicines release, including whole water body/regional impacts. The relationship and predictability of toxic algal blooms remains some way off. Modelling the complexities of degradation, resuspension and the effect of the scavenging process...

  16. Aquaculture: Algae. (Latest citations from the Life Sciences Collection data base). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains a minimum of 171 citations and includes a subject term index and title list.)

  17. Laminar Natural Convection of Newtonian and Non – Newtonian Fluids Inside Triangular Enclosure

    Directory of Open Access Journals (Sweden)

    Ala?a Abbas Muhadi

    2007-01-01

    Full Text Available In the present work, steady two – dimensional laminar natural convection heat transfer of Newtonian and non-Newtonian fluids inside isosceles triangular enclosure has been analyzed numerically for a wide range of the modified Rayleigh numbers of (103 ≤ Ra ≤ 105, with non-dimensional parameter (NE of Prandtl – Eyring model ranging from (0 to 10, and modified Prandtl number take in the range (Pr* =1,10, and 100. Two types of boundary conditions have been considered. The first, when the inclined walls are heated with different uniform temperatures and the lower wall is insulated. The second, when the bottom wall is heated by applying a uniform heat flux while the inclined walls at the constant cold temperature. Also, the non-Newtonian fluids under consideration were assumed to obey the Prandtl – Eyring model..The results are presented in terms of isotherms and streamlines to show the behavior of the fluid flow and temperature fields. In addition, some graphics are presented the relation between average Nusselt number and the various parameters. The results show the effect of non – dimensional parameter (NE on the velocity and temperature profiles. They also show that the average Nusselt number is a strong function of modified Rayleigh number, modified Prandtl number, non-dimensional parameter, and the boundary conditions. Four different correlations have been made to show the dependence of the average Nusselt number on the non-dimensional parameter, the modified Rayleigh and Prandtl numbers.

  18. Standard Guide for Selection of Test Methods for Interlayer Materials for Aerospace Transparent Enclosures

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This guide summarizes the standard test methods available for determining physical and mechanical characteristics of interlayer materials used in multi-ply aerospace transparent enclosures. 1.2 Interlayer materials are used to laminate glass-to-glass, glass-to-plastic, and plastic-to-plastic. Interlayer materials are basically transparent adhesives with high-quality optical properties. They can also serve as an energy absorbing medium, a fail-safe membrane to contain cockpit pressure and to prevent entry of impact debris; a strain insulator to accommodate different thermal expansion rates of members being laminated and as an adherent to prevent spalling of inner surface ply material fragments. The relative importance of an interlayer characteristic will be a function of the prime use it serves in its particular application. 1.3 This guide, as a summary of various methods in Section 2, is intended to facilitate the selection of tests that can be applied to interlayer materials. 1.4 The test methods list...

  19. Thermal Performance of Hollow Clay Brick with Low Emissivity Treatment in Surface Enclosures

    Directory of Open Access Journals (Sweden)

    Roberto Fioretti

    2014-10-01

    Full Text Available External walls made with hollow clay brick or block are widely used for their thermal, acoustic and structural properties. However, the performance of the bricks frequently does not conform with the minimum legal requirements or the values required for high efficiency buildings, and for this reason, they need to be integrated with layers of thermal insulation. In this paper, the thermal behavior of hollow clay block with low emissivity treatment on the internal cavity surfaces has been investigated. The purpose of this application is to obtain a reduction in the thermal conductivity of the block by lowering the radiative heat exchange in the enclosures. The aims of this paper are to indicate a methodology for evaluating the thermal performance of the brick and to provide information about the benefits that should be obtained. Theoretical evaluations are carried out on several bricks (12 geometries simulated with two different thermal conductivities of the clay, using a finite elements model. The heat exchange procedure is implemented in accordance with the standard, so as to obtain standardized values of the thermal characteristics of the block. Several values of emissivity are hypothesized, related to different kinds of coating. Finally, the values of the thermal transmittance of walls built with the evaluated blocks have been calculated and compared. The results show how coating the internal surface of the cavity provides a reduction in the thermal conductivity of the block, of between 26% and 45%, for a surface emissivity of 0.1.

  20. Factors affecting wild rabbit production in extensive breeding enclosures: how can we optimise efforts?

    Directory of Open Access Journals (Sweden)

    José Guerrero-Casado

    2013-09-01

    Full Text Available The declining rabbit population in the Iberian Peninsula has led hunters and authorities to rear rabbits in captivity systems for their subsequent release. One alternative method to intensive rabbitry systems is the use of extensive breeding enclosures, since they produce animals of greater quality for hunting and conservation purposes. However, some of the factors that affect rabbit production in breeding enclosures are still unknown. The present study used partial least squares regression (PLSR to analyse the effects of plot size, scrub cover, slope, initial rabbit abundance, the resources needed to dig warrens, predation and proximity to other enclosures on rabbit abundance. The results of our study show a positive effect of the number of other fenced plots within a radius of 3 km, a positive relationship with the availability of optimal resources for building warrens and a positive influence of intermediate values of scrub cover. According to our results, to maximise rabbit production in the enclosures it would be advisable to concentrate the restocking effort by ensuring that the restocking plots are close to each other, thus avoiding isolated enclosures. Furthermore, the selection of plots with an appropriate scrub cover and high availability of elements that favour the construction of warrens, such as large stones, sloping land or tall shrubs, may optimise results.

  1. 浅析英国议会圈地运动%On British Parliamentary Enclosure Movement

    Institute of Scientific and Technical Information of China (English)

    孙连娣

    2013-01-01

    议会圈地运动是英国在资产阶级掌握政权以后通过议会颁布相关的法案,以合法形式大规模圈占土地的过程。本文首先将议会圈地与早期圈地相比较,从而引出议会圈地运动所产生的原因、条件、过程和影响五个方面,为进一步论证议会圈地是小农土地所有者消亡的一个重要原因提供了史料依据。%Parliamentary Enclosure Movement is Britain after bourgeois power through Parliament enacted relevant legislation, to process legitimate form of massive encirclements within them. This paper will firstly compared parliamentary enclosure with the early enclosure, which led to Parliamentary Enclosure Movement generated conditions, process and effect five aspects reasons, in order to further demonstrate the historical evidence of parliamentary enclosure is one of the important reasons of peasant land owners.

  2. Experimental Study of Melting Heat Transfer in an Enclosure with Three Discrete Protruding Heat Sources

    Institute of Scientific and Technical Information of China (English)

    YonglinJu; ZhongqiChen; 等

    1998-01-01

    To explore the possibility of using solid-liquid phase change cooling to those periodically or intermittently operated electronic equipment,a detail of experimental study of time-dependent melting heat transfer in a rectangular enclosure with three discrete proturding heat sources is presented.A series of experimental measurement in an enclosure with phase change materials (PCM)of n-octadecane of experimental measurement in an enclosure with phase change materials(PCM) of -octadecane heated by three discrete protruding heat sources at a constant rate on one of its vertical wall has been described.The opposite wall of the enclosure is cooled at a constant temperature and all other walls of the enclosure are insulated.The time-dependent solid-liquid shapes of the interface during melting process,the variation of surface temperature and the effects of sulbcooling are investigated.An empirical correlation predicting the relationship between the liquid phase fraction and subcooling is given.

  3. Occurrence of Vibrio parahaemolyticus, Vibrio cholerae, and Vibrio vulnificus in the Aquacultural Environments of Taiwan.

    Science.gov (United States)

    Tey, Yao Hsien; Jong, Koa-Jen; Fen, Shin-Yuan; Wong, Hin-Chung

    2015-05-01

    The occurrence of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae in a total of 72 samples from six aquaculture ponds for groupers, milk fish, and tilapia in southern Taiwan was examined by the membrane filtration and colony hybridization method. The halophilic V. parahaemolyticus was only recovered in seawater ponds, with a high isolation frequency of 86.1% and a mean density of 2.6 log CFU/g. V. cholerae was found in both the seawater and freshwater ponds but preferentially in freshwater ponds, with a frequency of 72.2% and a mean density of 1.65 log CFU/g. V. vulnificus was identified mainly in seawater ponds, with an isolation frequency of 27.8%. The density of V. parahaemolyticus in seawater ponds was positively related to water temperature (Pearson correlation coefficient, r = 0.555) and negatively related to salinity (r = 2 0.333). The density of V. cholerae in all six ponds was positively related to water temperature (r = 0.342) and negatively related to salinity (r = 2 0.432). Two putatively pathogenic tdh(+) V. parahaemolyticus isolates (1.4% of the samples) and no ctx(+) V. cholerae isolates were identified. The experimental results may facilitate assessments of the risk posed by these pathogenic Vibrio species in Taiwan, where aquaculture provides a large part of the seafood supply.

  4. Phylogeny of the viral hemorrhagic septicemia virus in European aquaculture

    NARCIS (Netherlands)

    Cieslak, Michael; Mikkelsen, Susie S.; Skall, Helle F.; Baud, Marine; Diserens, Nicolas; Engelsma, Marc Y.; Haenen, Olga L.M.; Mousakhani, Shirin; Panzarin, Valentina; Wahli, Thomas; Olesen, Niels J.; Schütze, Heike

    2016-01-01

    One of the most valuable aquaculture fish in Europe is the rainbow trout, Oncorhynchus mykiss, but the profitability of trout production is threatened by a highly lethal infectious disease, viral hemorrhagic septicemia (VHS), caused by the VHS virus (VHSV). For the past few decades, the subgenogr

  5. Ocean modelling for aquaculture and fisheries in Irish waters

    Directory of Open Access Journals (Sweden)

    T. Dabrowski

    2015-06-01

    Full Text Available The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. A shellfish model that includes growth and physiological interactions of mussels with the ecosystem and is fully embedded in the 3-D numerical modelling framework has been developed at the Marine Institute. This shellfish model has a microbial module designed to predict levels of coliform contamination in mussels. This model can also be used to estimate the carrying capacity of embayments, assess impacts of pollution on aquaculture grounds and help to classify shellfish waters. The physical coastal model of southwest Ireland provides a three day forecast of shelf water movement in the region. This is assimilated into a new harmful algal bloom alert system used to inform end-users of potential toxic shellfish events and high biomass blooms that include fish killing species. Further services include the use of models to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the marine fisheries resources. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries.

  6. Fish to 2030 : Prospects for Fisheries and Aquaculture

    OpenAIRE

    World Bank

    2013-01-01

    This report analyzes global prospects for fisheries and aquaculture. The World Bank Group (WBG) Agriculture Action Plan 2013-15 summarizes critical challenges facing the global food and agriculture sector. An ever-increasing global population necessitates adequate food and nutrition for the growing population through increased production and reduced waste. Production increase must occur in...

  7. Peace Corps Aquaculture Training Manual. Training Manual T0057.

    Science.gov (United States)

    Peace Corps, Washington, DC. Information Collection and Exchange Div.

    This Peace Corps training manual was developed from two existing manuals to provide a comprehensive training program in fish production for Peace Corps volunteers. The manual encompasses the essential elements of the University of Oklahoma program that has been training volunteers in aquaculture for 25 years. The 22 chapters of the manual are…

  8. Aquaculture: A Course of Study for Sand Point Secondary School.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau. Office of Public Information and Publications.

    This program is designed to involve students in the economy of their community. It combines an interdisciplinary educational program with practical field and laboratory experience. This program provides opportunities in the area of aquaculture, controlled cultivation of marketable species and the total ecological corrections necessary to maintain…

  9. Developing low cost feed grade soybean protein concentrates for aquaculture

    Science.gov (United States)

    One emerging area in the global soy industry, particularly the U.S. soybean industry, has been developing soy-based feeds as an alternative protein source to meet the growing needs of aquaculture in China and elsewhere. Traditionally, fishmeal is a key protein ingredient in fish diets, but its sup...

  10. Impact of an aquaculture extension project in Bangladesh

    DEFF Research Database (Denmark)

    Rand, John; Tarp, Finn

    2009-01-01

    This paper is an impact study of key short- and long-run effects of the Danida supported Mymensingh Aquaculture Extension Project (MAEP) in Bangladesh, applying different matching and double difference estimators. Results are mixed. First, the paper finds a positive short-run impact on pond...

  11. Coping styles in farmed fish: consequences for aquaculture

    DEFF Research Database (Denmark)

    Castanheira, Maria Filipa; Conceição, Luís E.C.; Millot, Sandie

    2015-01-01

    on coping styles may contribute to improved sustainability of the aquaculture industry, including welfare and performance of farmed fish. Moreover, we will suggest areas for future research, where genetic basis (heritability/epigenetic) of coping styles, and the neuroendocrine mechanisms behind consistent...

  12. Microorganisms in recirculating aquaculture systems and their management

    NARCIS (Netherlands)

    Rurangwa, E.; Verdegem, M.C.J.

    2015-01-01

    Recirculation aquaculture systems (RASs) are increasingly considered as production systems of the future with a minimum ecological impact for the production of aquatic food. To maintain a good water quality and to produce quality and healthy fishery products, the systems depend on a diverse microbia

  13. Charting the Research Course for Sustainable Aquaculture in Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    Vun L. W.

    2016-01-01

    Full Text Available Due to arising needs and demands, aquaculture is currently the fastest growing food production sector. In order to increase yield and yet to remain sustainable, the challenges would be to minimise impact on the environment and ecosystem services. Aquaculture activity contributes significantly to Malaysia and also the state of Sabah’s economy and food security. Hence, the future changes in the environment as a result of rapid population growth and development would pose as threats to this industry in terms of quality, quantity and sustainability. Unforeseen environmental changes such as environmental pollution from other sources, climate change and the changes in policies would jeopardize the sustainability of this industry. In order to anticipate such impacts to the aquaculture activities, this paper set to chart a sustainable course for its development. Four important research courses were proposed: establishment of a sustainable framework, assessment of impacts of climate change, viability and vulnerability assessment due to future environmental changes and food security. Such findings would eventually allow the stakeholders to plan and manage the resources and aquaculture activities in such a way that foster sustainable food security and resilient aquatic ecosystems.

  14. Beyond net deficits: new priorities for an aquacultural geography

    NARCIS (Netherlands)

    Belton, B.; Bush, S.R.

    2014-01-01

    Geographers first identified aquaculture as an important field of study during the 1990s, pointing to a ‘net deficit’ in geographical knowledge about the activity. This paper examines how far geographers have come in bridging this knowledge deficit in the last 20 years. While increasing attention ha

  15. Bridging the gap between aquaculture and the information sciences

    Directory of Open Access Journals (Sweden)

    Jens G. Balchen

    1986-10-01

    Full Text Available The aquaculture industry is traditionally a low technology industry. But as demands on productivity, quality and availability are increasing the application of modern industrial technology is inevitable. After the fundamental problems of biology and of civil, mechanical and chemical engineering have been resolved, major progress may be expected through the application of the tools of the information sciences.

  16. Sustainable aquaculture in ponds: Principles, practices and limits

    NARCIS (Netherlands)

    Bosma, R.H.; Verdegem, M.C.J.

    2011-01-01

    The global aquaculture production of crustaceans, shellfish and fish has to increase to satisfy the growing demand and also to compensate for the reduced capture from overexploited fisheries. Extending the area of brackish and fresh water ponds is constrained by the limited availability of land and

  17. Phylogeny of the Viral Hemorrhagic Septicemia Virus in European Aquaculture

    DEFF Research Database (Denmark)

    Cieslak, Michael; Mikkelsen, Susie Sommer; Skall, Helle F.

    2016-01-01

    One of the most valuable aquaculture fish in Europe is the rainbow trout, Oncorhynchus mykiss, but the profitability of trout production is threatened by a highly lethal infectious disease, viral hemorrhagic septicemia (VHS), caused by the VHS virus (VHSV). For the past few decades, the subgenogr...

  18. International cooperation on the use of peracetic acid in aquaculture

    Science.gov (United States)

    This presentation will discuss collaborative efforts on research to evaluate the usefulness of peracetic acid (PAA) as a therapeutant in aquaculture. Research has been underway since 2009 with a scientist from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (Berlin, Germany). Ther...

  19. Ocean modelling for aquaculture and fisheries in Irish waters

    Science.gov (United States)

    Dabrowski, T.; Lyons, K.; Cusack, C.; Casal, G.; Berry, A.; Nolan, G. D.

    2016-01-01

    The Marine Institute, Ireland, runs a suite of operational regional and coastal ocean models. Recent developments include several tailored products that focus on the key needs of the Irish aquaculture sector. In this article, an overview of the products and services derived from the models are presented. The authors give an overview of a shellfish model developed in-house and that was designed to predict the growth, the physiological interactions with the ecosystem, and the level of coliform contamination of the blue mussel. As such, this model is applicable in studies on the carrying capacity of embayments, assessment of the impacts of pollution on aquaculture grounds, and the determination of shellfish water classes. Further services include the assimilation of the model-predicted shelf water movement into a new harmful algal bloom alert system used to inform end users of potential toxic shellfish events and high biomass blooms that include fish-killing species. Models are also used to identify potential sites for offshore aquaculture, to inform studies of potential cross-contamination in farms from the dispersal of planktonic sea lice larvae and other pathogens that can infect finfish, and to provide modelled products that underpin the assessment and advisory services on the sustainable exploitation of the resources of marine fisheries. This paper demonstrates that ocean models can provide an invaluable contribution to the sustainable blue growth of aquaculture and fisheries.

  20. Coral aquaculture: applying scientific knowledge to ex situ production

    NARCIS (Netherlands)

    Leal, M.C.; Ferrier-Pagès, C.; Petersen, D.; Osinga, R.

    2016-01-01

    Coral aquaculture is an activity of growing interest due to the degradation of coral reefs worldwide and concomitant growing demand for corals by three industries: marine ornamental trade, pharmaceutical industry and reef restoration. Although captive breeding and propagation of corals is a well-kno

  1. How is shrimp aquaculture transforming coastal livelihoods and lagoons in Estero Real, Nicaragua? The need to integrate social-ecological research and ecosystem-based approaches.

    Science.gov (United States)

    Benessaiah, Karina; Sengupta, Raja

    2014-08-01

    Ecosystem-based approaches to aquaculture integrate environmental concerns into planning. Social-ecological systems research can improve this approach by explicitly relating ecological and social dynamics of change at multiple scales. Doing so requires not only addressing direct effects of aquaculture but also considering indirect factors such as changes in livelihood strategies, governance dynamics, and power relations. We selected the community of Puerto Morazán, Nicaragua as a case study to demonstrate how the introduction of small-scale aquaculture radically transformed another key livelihood activity, lagoon shrimp fishing, and the effects that these changes have had on lagoons and the people that depend on them. We find that shrimp aquaculture played a key role in the collapse, in the 1990s, of an existing lagoon common-property management. Shrimp aquaculture-related capital enabled the adoption of a new fishing technique that not only degraded lagoons but also led to their gradual privatization. The existence of social ties between small-scale shrimp farmers and other community members mitigated the impacts of privatization, illustrating the importance of social capital. Since 2008, community members are seeking to communally manage the lagoons once again, in response to degraded environmental conditions and a consolidation of the shrimp industry at the expense of smaller actors. This research shows that shrimp aquaculture intersects with a complex set of drivers, affecting not only how ecosystems are managed but also how they are perceived and valued. Understanding these social-ecological dynamics is essential to implement realistic policies and management of mangrove ecosystems and address the needs of resource-dependent people.

  2. Fishery and Aquaculture Relationship in the Mediterranean: Present and Future

    Directory of Open Access Journals (Sweden)

    G. RELINI

    2012-12-01

    Full Text Available Although the Mediterranean represents only 0.8% of the world seas, it is the site of a very long-established fishing activity, characterized mainly by multispecific catch and by artisanal or coastal activity, resulting from a mosaic of very diversified structures and gears, along more than 45,000 km of coastline. Two main biological features of this sea are the occurrence of a large richness of species (it represents 5.5% - 7% of world marine fauna and 16.6% of macrophyta, which stands in contrast with its ‘trophic poverty’ and the absence of large monospecific fishery, except for some small and large pelagic fish. Another biological characteristic of Mare Nostrumis the high invasion of exotic species, some exploited by fishery and aquaculture, some others quite dangerous. For the entire Mediterranean and Black Sea, the production (catch + aquaculture had been steadily increasing over the period 1972-1988 from 1,140,000 t to 2,080,000 t . The period 1988-1991 has shown a drastic drop in catches (in 1991: 1,400,000 t. From 1990 to 1995 the total catch increased to 1,701,379 t then decreased and in 2000 reached 1,485,046 t . In 2000 Turkey had the first place with 496,174 t, 26.9% of the total value (1,846,026 t, including fishing and aquaculture, followed by Italy with 25%, Greece 9%, Spain 7.6% and Algeria 5.4%. As in many parts of the world, aquaculture production in the Mediterranean is rapidly expanding. In 1970 the total aquaculture production was about 18,297 t of which 74.3% produced in Italy. In 2000 a value of 358,614 t was reached, about 1/4 of the total fishery catch, while the world aquaculture production corresponds to half of the world total catch. Italy is still the main producer with 46.7% , followed by Greece with 21.5%, Turkey 9.9% and France 6.7%. A sharp drop in the production of the European eel ( Anguilla anguilla and of the European flat oyster ( Ostrea edulis is recorded. Positive and negative interactions between

  3. Thermal Stability Influence of the Enclosure Structure on the Building’s Energy Efficiency

    Directory of Open Access Journals (Sweden)

    Zaborova Daria

    2016-01-01

    Full Text Available Thermal stability of the enclosure structures is one of the most important objective in the building design. Thermal processes in the wall depend not only on the internal and external air temperature, but also on many other factors. Therefore, complexity of this process make heat conservation in the room to be an actual problem. This paper presents dependence between thermal stability of the enclosure structure and its design. It was shown that thermophysical characteristics of materials directly affect the thermal processes in the wall. For the research, three frequently used types of enclosure structure in Russia were taken. For each wall was found the average temperature and cooling time. As a result, it was found that the higher values of thermal conductivity, specific heat and material density are, the higher average temperature of the wall is.

  4. Implementation and control of asymmetric thermal environment in two-dimensional rectangular enclosure

    Institute of Scientific and Technical Information of China (English)

    SHEN Lin; DENG Qi-hong

    2005-01-01

    Laminar natural convection in an enclosure divided by an adiabatic partition on its bottom with two unequal discrete heat sources was investigated numerically. The effect of the partition on the flow structure and heat transfer characteristics in enclosure under asymmetric heating condition was studied. The parameters are the Rayleigh number (1 × 104 ≤Ra≤1 × 106) and the height of partition (0≤h/H≤0. 70). The streamlines are produced for various Rayleigh numbers. The results reflected by variations of the average Nusselt number in terms of the height of partition illustrates the convection heat transfer in the enclosure. The role of the partition is to weaken or cut off the heat removal rate from the strong heat source to the weak heat source. It is analyzed that the optimum height of the partition to break the linkage between the strong and weak heat source increases with increasing Rayleigh number.

  5. Status of cleanliness maintaining in target beam enclosures in SG III facilities and contamination sources analysis

    Science.gov (United States)

    Wang, Meicong; Wang, Baoxu; Miao, Xinxiang; Cheng, Xiaofeng; Wu, Wenkai

    2014-09-01

    In SGIII lasers there are large number of transport mirrors in target beam enclosures. Surface contaminations could easily introduce optical damage, and increase laser energy loss under high laser influence conditions. It is significant for lasers to control contamination and maintain cleanliness. In SGIII prototype, the target beam enclosures are test to be seriously contaminated after about two years of routine operations. Volume cleanliness in mirror boxes are monitored through 24 hours before, during and after a shot. Ingredients of particle and organics are tested. Reconstructions are performed on the mirror boxes to remove debris and keep cleanliness for upward facing surface of mirrors effectively. In SGIII facility some contaminations are found in beam enclosures and on the mirrors after several months of test running. Contaminations sources are analyzed to further know about the contamination mechanisms. Some engineering countermeasures are introduced for controlling contamination and keeping cleanliness for optics.

  6. Numerical studies of convective heat transfer in an inclined semi-annular enclosure

    Science.gov (United States)

    Wang, L.-W.; Chai, A.-T.; Yung, C.-N.; Rashidnia, N.

    1989-01-01

    Natural convection heat transfer in a two-dimensional differentially heated semiannular enclosure is studied. The enclosure is isothermally heated and cooled at the inner and outer walls, respectively. A commercial software based on the SIMPLER algorithm was used to simulate the velocity and temperature profiles. Various parameters that affect the momentum and heat transfer processes were examined. These parameters include the Rayleigh number, Prandtl number, radius ratio, and the angle of inclination. A flow regime extending from conduction-dominated to convection-dominated flow was examined. The computed results of heat transfer are presented as a function of flow parameter and geometric factors. It is found that the heat transfer rate attains a minimum when the enclosure is tilted about +50 deg with respect to the gravitational direction.

  7. Numerical studies of convective heat transfer in an inclined semiannular enclosure

    Science.gov (United States)

    Wang, Lin-Wen; Yung, Chain-Nan; Chai, An-Ti; Rashidnia, Nasser

    1989-01-01

    Natural convection heat transfer in a two-dimensional differentially heated semiannular enclosure is studied. The enclosure is isothermally heated and cooled at the inner and outer walls, respectively. A commercial software based on the SIMPLER algorithm was used to simulate the velocity and temperature profiles. Various parameters that affect the momentum and heat transfer processes were examined. These parameters include the Rayleigh number, Prandtl number, radius ratio, and the angle of inclination. A flow regime extending from conduction-dominated to convection-dominated flow was examined. The computed results of heat transfer are presented as a function of flow parameter and geometric factors. It is found that the heat transfer rate attains a minimum when the enclosure is tilted about +50 deg with respect to the gravitational direction.

  8. Counter-insurgents of the blue revolution? Parasites and diseases affecting aquaculture and science.

    Science.gov (United States)

    Blaylock, Reginald B; Bullard, Stephen A

    2014-12-01

    Aquaculture is the fastest-growing segment of food production and is expected to supply a growing portion of animal protein for consumption by humans. Because industrial aquaculture developed only recently compared to industrial agriculture, its development occurred within the context of a growing environmental awareness and acknowledgment of environmental issues associated with industrial farming. As such, parasites and diseases have become central criticisms of commercial aquaculture. This focus on parasites and diseases, however, has created a nexus of opportunities for research that has facilitated considerable scientific advances in the fields of parasitology and aquaculture. This paper reviews Myxobolus cerebralis , Lepeophtheirus salmonis , white spot syndrome virus, and assorted flatworms as select marquee aquaculture pathogens, summarizes the status of the diseases caused by each and their impacts on aquaculture, and highlights some of the significant contributions these pathogens have made to the science of parasitology and aquaculture.

  9. A review on analytical techniques for natural convection investigation in a heated closed enclosure: Case study

    Directory of Open Access Journals (Sweden)

    Minea Alina Adriana

    2015-01-01

    Full Text Available The aim of this paper is to present a theoretical analysis of a few convection problems. The investigations were started from the geometry of a classic muffle manufactured furnace. During this analytical study, different methodologies have been carefully chosen in order to compare and evaluate the effects of applying different analytical methods of the convection heat transfer processes. In conclusion, even if there are available a lot of analytical methods, natural convection in enclosed enclosures can be studied correctly only with numerical analysis. Also, in this article is presented a case study on natural convection application in a closed heated enclosure.

  10. Analytical modeling of natural convection in a tall rectangular enclosure with multiple disconnected partitions

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Young Min; Kim, Seong Hoon; Seo, Jae Kwang; Kim, Young In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-08-15

    In this study, laminar natural circulation and heat transfer in a tall rectangular enclosure with disconnected vertical partitions inside were investigated. Analytical expressions were developed to predict the circulation flow rate and the average Nusselt number in a partially partitioned enclosure with isothermal side walls at different temperatures and insulated top and bottom walls. The proposed formulas are then validated against numerical results for modified Rayleigh numbers of up to 106. The impacts of the governing parameters are also examined along with a discussion of the heat transfer regimes.

  11. Rural aquaculture as a sustainable alternative for forest conservation in the Monarch Butterfly Biosphere Reserve, Mexico.

    Science.gov (United States)

    López-García, José; Manzo-Delgado, Lilia L; Alcántara-Ayala, Irasema

    2014-06-01

    Forest conservation plays a significant role in environmental sustainability. In Mexico only 8.48 million ha of forest are used for conservation of biodiversity. Payment for Environmental Services in the Monarch Butterfly Biosphere Reserve, one of the most important national protected areas, contributes to the conservation of these forests. In the Reserve, production of rainbow trout has been important for the rural communities who need to conserve the forest cover in order to maintain the hibernation cycle of the butterfly. Aquaculture is a highly productive activity for these protected areas, since it harnesses the existing water resources. In this study, changes from 1999 to 2012 in vegetation and land-use cover in the El Lindero basin within the Reserve were evaluated in order to determine the conservation status and to consider the feasibility of aquaculture as a means of sustainable development at community level. Evaluation involved stereoscopic interpretation of digital aerial photographs from 1999 to 2012 at 1:10,000 scale, comparative analysis by orthocorrected mosaics and restitution on the mosaics. Between 1999 and 2012, forested land recovered by 28.57 ha (2.70%) at the expense of non-forested areas, although forest degradation was 3.59%. Forest density increased by 16.87%. In the 46 ha outside the Reserve, deforestation spread by 0.26%, and land use change was 0.11%. The trend towards change in forest cover is closely related to conservation programmes, particularly payment for not extracting timber, reforestation campaigns and surveillance, whose effects have been exploited for the development of rural aquaculture; this is a new way to improve the socio-economic status of the population, to avoid logging and to achieve environmental sustainability in the Reserve.

  12. Nutrients' removal from aquaculture wastewater using the macroalgae Gracilaria birdiae

    Energy Technology Data Exchange (ETDEWEB)

    Marinho-Soriano, E.; Nunes, S.O.; Carneiro, M.A.A.; Pereira, D.C. [Universidade Federal do Rio Grande do Norte, Depto. de Oceanografia e Limnologia, Via Costeira, Praia de Mae Luiza, s/n, Natal, RN 59014-100 (Brazil)

    2009-02-15

    Intensive aquaculture releases large amount of nutrients into aquatic ecosystems and can lead to eutrophication of coastal waters. Studies conducted in aquaculture systems have demonstrated that the seaweeds are efficient in reducing nutrients and at the same time provides extra income, when species of economic importance are used. This study was conducted to evaluate whether Gracilaria birdiae could be cultivated efficiently for the production of useful algal biomass and removal of nutrients from shrimp pond effluents. The results obtained showed a gradual increase in biomass and relative growth rate (RGR) over the experimental period. Mean RGR between the weeks varied significantly (p < 0.01), reaching a maximum of 3.6 {+-} 0.35% d{sup -1} and a minimum of 1.6 {+-} 0.52% d{sup -1}. The mean for the whole period was 2.6% d{sup -1}. The biofiltration capacity of G. birdiae was confirmed by the significantly reduced concentration of the three nutrients analyzed (PO{sub 4}{sup 3-}, NH{sub 4}{sup +} and NO{sub 3}{sup -}) over the study period. The concentration of PO{sub 4}{sup 3-} decreased by 93.5%, NH{sub 4}{sup +} by 34% and NO{sub 3}{sup -} by 100% after the 4-week experimental period. The results obtained in this study indicated that G. birdiae can be used in aquaculture systems as a biofilter. In addition, the macroalgae biomass produced offers alternative source of raw material for the extraction of the phycocolloid agar, human food and animal feed. (author)

  13. Increasing pressure on freshwater resources due to terrestrial feed ingredients for aquaculture production.

    Science.gov (United States)

    Pahlow, M; van Oel, P R; Mekonnen, M M; Hoekstra, A Y

    2015-12-01

    As aquaculture becomes more important for feeding the growing world population, so too do the required natural resources needed to produce aquaculture feed. While there is potential to replace fish meal and fish oil with terrestrial feed ingredients, it is important to understand both the positive and negative implications of such a development. The use of feed with a large proportion of terrestrial feed may reduce the pressure on fisheries to provide feed for fish, but at the same time it may significantly increase the pressure on freshwater resources, due to water consumption and pollution in crop production for aquafeed. Here the green, blue and gray water footprint of cultured fish and crustaceans related to the production of commercial feed for the year 2008 has been determined for the major farmed species, representing 88% of total fed production. The green, blue and gray production-weighted average feed water footprints of fish and crustaceans fed commercial aquafeed are estimated at 1629 m3/t, 179 m3/t and 166 m3/t, respectively. The estimated global total water footprint of commercial aquafeed was 31-35 km3 in 2008. The top five contributors to the total water footprint of commercial feed are Nile tilapia, Grass carp, Whiteleg shrimp, Common carp and Atlantic salmon, which together have a water footprint of 18.2 km3. An analysis of alternative diets revealed that the replacement of fish meal and fish oil with terrestrial feed ingredients may further increase pressure on freshwater resources. At the same time economic consumptive water productivity may be reduced, especially for carnivorous species. The results of the present study show that, for the aquaculture sector to grow sustainably, freshwater consumption and pollution due to aquafeed need to be taken into account.

  14. Aquaculture growth and Fatty acid profile of Hediste diversicolor fed with three different diets

    Directory of Open Access Journals (Sweden)

    António Santos

    2014-06-01

    Full Text Available Hediste diversicolor (O.F. Müller, 1776 or so called common ragworm, is an Annelida polychaeta is typically an inhabitant of shallow marine and brackish waters in different parts of Europe. This species has a high physiological tolerance to extreme environmental factors such as salinity, temperature and dissolved oxygen levels, which can be grown and reproduced in different types of sediment. In the field and also under laboratory conditions this worm can utilize different types of food. To improve the aquaculture of H. diversicolor we have determined the growth, survival rates and fatty acid profile of juvenile worms fed with three different diets for 2 months. This experiment was carried out with juvenile worms reared in aquaculture laboratory of Polytechnic Institute of Leiria and were fed with Aquagold (seabream dry food, moist sole (semi wet pellets for cultured sole and mackerel fillet. The temperature was maintained at 20 ± 1°C with 15 of salinity. H. diversicolor juveniles were placed in three replicates for each diet, with 30 worms per replicate. The higher growth rate was observed when the juveniles were fed with Aquagold (0,146 g d-1 for 10 individuals, and 100% survival rate was a result of moist sole diet, probably related to the immunostimulant included in this feed. The major fatty acids found in the juveniles fed with the three diets were palmitc acid (16:0, oleic acid (18:1n9; eicosapentanoic acid (20:5n3 and docosahexaenoic acid (22:6n3. Although results shown that mackerel fillet was not the diet with the higher growth rate and final weight achieved, when compared to the other two diets, but it is proved that it can be suitable for H. diversicolor aquaculture.

  15. The Application of Integrated Multi Trophic Aquaculture (IMTA Using Stratified Double Net Rounded Cage (SDFNC for Aquaculture Sustainability

    Directory of Open Access Journals (Sweden)

    Sapto P. Putro

    2015-12-01

    Full Text Available The increase of fishery production nationally and internationally may impact on the potential emergence of a variety of environmental problems. The application of sustainable aquaculture is urgently needed by breeding fish for commercial purposes in a manner such that it has a minimum impact on the environment, contributing to the development of local communities and generating economic benefits. The design of the cage and farming practice in aquaculture activities are the important steps to ensure that farming activity is still observed in order to anticipate the risk of organic enrichment caused by the activities. The application of Integrated Multi-Trophic Aquaculture  (IMTA on the Stratified Double Floating Net Cage  (SDFNC integrated with biomonitoring are an appropriate solution to the ongoing productive farming practices. IMTA is an aquaculture practice using more than one species of biotas which have ecologically mutual relationship as a part of the food chain in the area at the same time. The application of IMTA allows farmers to get several aquaculture products in the same area without increasing the horizontal area of the farms. At first, the SDFNC has been applied for farming Cyprinus carpio and Tilapia niloticus as polyculture system in freshwater ecosystem of Rawapening Lake, Central Java. Its operation has been able to increase the production capacity of at least 75% of conventional cages. The application of SDFNC-IMTA using milkfish (Chanos Chanos, seaweed (Kappaphycus alvarezii, and white shrimp (Litopenaeus vannamei has been able to minimize the impact and maintain the water ecosystem in the Gulf Awerange, South Sulawesi.

  16. Strategies to enhance the competitiveness of semi-intensive aquaculture systems in costal earth ponds: the organic aquaculture approach

    Directory of Open Access Journals (Sweden)

    Manuel Sardinha

    2014-06-01

    Full Text Available Earthen ponds are the main production system for European seabass (Dicentrarchus labrax and gilthead seabream (Sparus aurata in Portugal and in Southern Spain. Production costs in this low productivity farming system are higher compared to intensive cage farms, and its economic sustainability depends on product differentiation and optimization of production. The development of new farming protocols, to enhance productivity of ponds and lagoons, or the implementation of certification processes to add value to products from extensive and semi-intensive systems, could render these activities more economics benefits and be attractive for a new generation of farmers. One clear strategy to differentiate and add value to seabream produced in semi-intensive systems is its production under organic standards. Feeds often represent 40-60% of the operational costs of fish farming. In relation to the traditional feeds, the organic certified feeds currently present a price-differential of about +30%. To assess it economic feasibility, it is therefore essential to validate if such higher feeding costs will represent an increase on productivity (fish growth and feed conversion or can be fully integrated in the final sale price. Throughout a full production cycle of gilthead seabream (from 9 grams until >350 grams, a series of trials allowed us to assess the effects of: a an organic certified feed; b variable feeding levels (100 and 80% of recommendations; and c culture density (0.5 and 1.0 kg/m3 on the overall growth performance, body composition and environmental impact at the fish farm level. Results show that growth performance (weight gain and feed conversion ratio of seabream fed the organic feed was similar to that found in fish fed a traditional diet. With the organic feed, a reduction of the feeding level by 20% of the manufacturer recommendations led to a lower growth, while a similar reduction on the feeding level of the traditional feed had no impact

  17. Cooling a solar telescope enclosure: plate coil thermal analysis

    Science.gov (United States)

    Gorman, Michael; Galapon, Chriselle; Montijo, Guillermo; Phelps, LeEllen; Murga, Gaizka

    2016-08-01

    The climate of Haleakalā requires the observatories to actively adapt to changing conditions in order to produce the best possible images. Observatories need to be maintained at a temperature closely matching ambient or the images become blurred and unusable. The Daniel K. Inouye Solar Telescope is a unique telescope as it will be active during the day as opposed to the other night-time stellar observatories. This means that it will not only need to constantly match the ever-changing temperature during the day, but also during the night so as not to sub-cool and affect the view field of other telescopes while they are in use. To accomplish this task, plate coil heat exchanger panels will be installed on the DKIST enclosure that are designed to keep the temperature at ambient temperature +0°C/-4°C. To verify the feasibility of this and to validate the design models, a test rig has been installed at the summit of Haleakalā. The project's purpose is to confirm that the plate coil panels are capable of maintaining this temperature throughout all seasons and involved collecting data sets of various variables including pressures, temperatures, coolant flows, solar radiations and wind velocities during typical operating hours. Using MATLAB, a script was written to observe the plate coil's thermal performance. The plate coil did not perform as expected, achieving a surface temperature that was generally 2ºC above ambient temperature. This isn't to say that the plate coil does not work, but the small chiller used for the experiment was undersized resulting in coolant pumped through the plate coil that was not supplied at a low enough temperature. Calculated heat depositions were about 23% lower than that used as the basis of the design for the hillers to be used on the full system, a reasonable agreement given the fact that many simplifying assumptions were used in the models. These were not carried over into the testing. The test rig performance showing a 23% margin

  18. Chlamydial infections of fish: diverse pathogens and emerging causes of disease in aquaculture species.

    Science.gov (United States)

    Stride, M C; Polkinghorne, A; Nowak, B F

    2014-05-14

    Chlamydial infections of fish are emerging as an important cause of disease in new and established aquaculture industries. To date, epitheliocystis, a skin and gill disease associated with infection by these obligate intracellular pathogens, has been described in over 90 fish species, including hosts from marine and fresh water environments. Aided by advances in molecular detection and typing, recent years have seen an explosion in the description of these epitheliocystis-related chlamydial pathogens of fish, significantly broadening our knowledge of the genetic diversity of the order Chlamydiales. Remarkably, in most cases, it seems that each new piscine host studied has revealed the presence of a phylogenetically unique and novel chlamydial pathogen, providing researchers with a fascinating opportunity to understand the origin, evolution and adaptation of their traditional terrestrial chlamydial relatives. Despite the advances in this area, much still needs to be learnt about the epidemiology of chlamydial infections in fish if these pathogens are to be controlled in farmed environments. The lack of in vitro methods for culturing of chlamydial pathogens of fish is a major hindrance to this field. This review provides an update on our current knowledge of the taxonomy and diversity of chlamydial pathogens of fish, discusses the impact of these infections on the health, and highlights further areas of research required to understand the biology and epidemiology of this important emerging group of fish pathogens of aquaculture species.

  19. Using the H-index to assess disease priorities for salmon aquaculture.

    Science.gov (United States)

    Murray, Alexander G; Wardeh, Maya; McIntyre, K Marie

    2016-04-01

    Atlantic salmon's (Salmo salar) annual aquaculture production exceeds 2M tonnes globally, and for the UK forms the largest single food export. However, aquaculture production is negatively affected by a range of different diseases and parasites. Effort to control pathogens should be focused on those which are most "important" to aquaculture. It is difficult to specify what makes a pathogen important; this is particularly true in the aquatic sector where data capture systems are less developed than for human or terrestrial animal diseases. Mortality levels might be one indicator, but these can cause a range of different problems such as persistent endemic losses, occasional large epidemics or control/treatment costs. Economic and multi-criteria decision methods can incorporate this range of impacts, however these have not been consistently applied to aquaculture and the quantity and quality of data required is large, so their potential for comparing aquatic pathogens is currently limited. A method that has been developed and applied to both human and terrestrial animal diseases is the analysis of published scientific literature using the H-index method. We applied this method to salmon pathogens using Web of Science searches for 23 pathogens. The top 3 H-indices were obtained for: sea lice, furunculosis, and infectious salmon anaemia; post 2000, Amoebic Gill Disease (AGD) replaced furunculosis. The number of publications per year describing bacterial disease declined significantly, while those for viruses and sea lice increased significantly. This reflects effective bacterial control by vaccination, while problems related to viruses and sea lice have increased. H-indices by country reflected different national concerns (e.g. AGD ranked top for Australia). Averaged national H-indices for salmon diseases tend to increase with log of salmon production; countries with H-Indices significantly below the trend line have suffered particularly large disease losses. The H

  20. The impact of water exchange rate and treatment processes on water-borne hormones in recirculation aquaculture systems containing sexually maturing Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled seven-month study was conducted in six replicated water recirculation aquaculture systems (WRAS) to assess post-smolt Atlantic salmon (Salmo salar) performance in relation to WRAS water exchange rate. Unexpectedly high numbers of precocious sexually mature fish were observed in all WRAS...

  1. Evaluation of ozonation on levels of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout Oncorhynchus mykiss from water recirculation aquaculture systems

    Science.gov (United States)

    Common “off-flavors” in fish cultured in water recirculation aquaculture systems (WRAS) are “earthy” and “musty” due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Previously, ozone addition has been applied to WRAS at relatively low doses to break...

  2. Comparative analysis of selected semi-persistent and emerging pollutants in wild-caught fish and aquaculture associated fish using Bogue (Boops boops) as sentinel species.

    Science.gov (United States)

    Henríquez-Hernández, Luis Alberto; Montero, Daniel; Camacho, María; Ginés, Rafael; Boada, Luis D; Ramírez Bordón, Besay; Valerón, Pilar F; Almeida-González, Maira; Zumbado, Manuel; Haroun, Ricardo; Luzardo, Octavio P

    2017-03-01

    The marine environment acts as a sink for diverse anthropogenic pollutants, although the environmental contamination may be non-uniformly distributed. In recent decades, the aquaculture sector has experienced a steady growth postulating as a good alternative for seafood production. However, a social debate exits about the differential level of pollutants in wild and farmed species. This study was designed to evaluate the level of pollutants in a sentinel species: Bogue (Boops boops) associated and non-associated to fish-farm cages. A total of 82 chemical substances were determined by gas chromatography-mass spectrometry, including persistent (polychlorobiphenyls (PCBs) and organochlorine pesticides (OCPs)), semi-persistent (bromodiphenyl ethers (BDEs) and polycyclic aromatic hydrocarbons (PAHs)), and emerging pollutants (such as organophosphate flame retardants (OPFRs) and UV-filters). In general, aquaculture-associated bogues showed lower levels of semi-persistent and emerging pollutants than wild-caught fish, especially when sums were considered. Thus, sum of BDEs was significantly lower in the aquaculture group (p=0.01). A similar trend was also observed for benzo(a)anthracene, the UV-filter 2-ethylhexyl-p-methoxycinnamate and some OPFRs. In the case of persistent pollutants, the sum of dioxin-like PCBs and sum of DDTs were lower in the group of wild-caught bogues (p=0.034 and p=0.003, respectively) than in aquaculture-associated bogues, as previously described for some aquaculture species. Fish feed appear as an important factor in the uptake of such substances suggesting a diet intervention to reduce their levels in the aquaculture products. Another interesting result is that for almost all chemical substances analyzed, bogues captured near sewage outfalls showed the highest levels of pollutants, pointing out the need of stringent measures for wastewater treatment units discharging in coastal areas. On the light of these results, further research in specific

  3. A Study of the Aquaculture Industry in Texas to Assist in Establishing Aquaculture as a Course Offering in Agricultural Science and Technology. Final Report.

    Science.gov (United States)

    Dillingham, John; And Others

    A 1989-90 project determined the knowledge and skills necessary for employment in the aquaculture industry. The study identified technical materials and other resources available in private industry and higher education institutions. Two surveys determined the status of aquaculture in Texas school districts and identified tasks performed by…

  4. 46 CFR 111.83-5 - Bottom entrance and protected enclosures.

    Science.gov (United States)

    2010-10-01

    ... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Shore Connection Boxes § 111.83-5 Bottom entrance and protected enclosures. Each shore connection box must have a bottom entrance for the shore connection cable. The box must provide protection to the shore connection when the connection is in use....

  5. Experimental study of humidity distribution inside electronic enclosure and effect of internal heating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2016-01-01

    tested by measuring the leakage current on inter-digitated test comb patterns which are pre-contaminated with sodium chloride and placed inside the enclosure.Results showed that exposure to cycling temperature leads to a significant change of internal water vapour concentration, where the maximum value...

  6. 9 CFR 3.61 - Primary enclosures used to transport live rabbits.

    Science.gov (United States)

    2010-01-01

    ... live rabbits. 3.61 Section 3.61 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... and Transportation of Rabbits Transportation Standards § 3.61 Primary enclosures used to transport live rabbits. No person subject to the Animal Welfare regulations shall offer for transportation...

  7. In-situ localized carbon nanotube growth inside partially sealed enclosures

    NARCIS (Netherlands)

    Burgt, Y. van de; Champion, A.; Bellouard, Y.

    2013-01-01

    Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition te

  8. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Science.gov (United States)

    2010-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal...

  9. Numerical Study of Natural Convection within a Wavy Enclosure Using Meshfree Approach: Effect of Corner Heating

    Directory of Open Access Journals (Sweden)

    Sonam Singh

    2014-01-01

    Full Text Available This paper presents a numerical study of natural convection within a wavy enclosure heated via corner heating. The considered enclosure is a square enclosure with left wavy side wall. The vertical wavy wall of the enclosure and both of the corner heaters are maintained at constant temperature, Tc and Th, respectively, with Th>Tc while the remaining horizontal, bottom, top and side walls are insulated. A penalty element-free Galerkin approach with reduced gauss integration scheme for penalty terms is used to solve momentum and energy equations over the complex domain with wide range of parameters, namely, Rayleigh number (Ra, Prandtl number (Pr, and range of heaters in the x- and y-direction. Numerical results are represented in terms of isotherms, streamlines, and Nusselt number. It is observed that the rate of heat transfer depends to a great extent on the Rayleigh number, Prandtl number, length of the corner heaters and the shape of the heat transfer surface. The consistent performance of the adopted numerical procedure is verified by comparison of the results obtained through the present meshless technique with those existing in the literature.

  10. 9 CFR 3.14 - Primary enclosures used to transport live dogs and cats.

    Science.gov (United States)

    2010-01-01

    ... live dogs and cats. 3.14 Section 3.14 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION..., Treatment, and Transportation of Dogs and Cats 1 Transportation Standards § 3.14 Primary enclosures used to transport live dogs and cats. Any person subject to the Animal Welfare regulations (9 CFR parts 1, 2, and...

  11. 32 CFR Enclosure 2 - Requirements for Environmental Considerations-Foreign Nations and Protected Global Resources

    Science.gov (United States)

    2010-07-01

    ... States, or resources of global importance that have been designated for protection. C. Environmental... this enclosure. a. An environmental review is a survey of the important environmental issues involved... survey of the important environmental issues associated with the proposed action that is to be...

  12. Investigations into the dynamics of aerosols in enclosures as used for air pollution studies

    NARCIS (Netherlands)

    Vate, van de J.F.

    1980-01-01

    This thesis treats aerosol behaviour under various conditions in enclosed spaces. Knowledge of this behaviour is of importance for the use of aerosol-filled enclosures as a supply of aerosol, as a means for aerosol characterization and for so-called smog chambers for air pollution research (mainly f

  13. ZFS on RBODs - Leveraging RAID Controllers for Metrics and Enclosure Management

    Energy Technology Data Exchange (ETDEWEB)

    Stearman, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-30

    Traditionally, the Lustre file system has relied on the ldiskfs file system with reliable RAID (Redundant Array of Independent Disks) storage underneath. As of Lustre 2.4, ZFS was added as a backend file system, with built-in software RAID, thereby removing the need of expensive RAID controllers. ZFS was designed to work with JBOD (Just a Bunch Of Disks) storage enclosures under the Solaris Operating System, which provided a rich device management system. Long time users of the Lustre file system have relied on the RAID controllers to provide metrics and enclosure monitoring and management services, with rich APIs and command line interfaces. This paper will study a hybrid approach using an advanced full featured RAID enclosure which is presented to the host as a JBOD, This RBOD (RAIDed Bunch Of Disks) allows ZFS to do the RAID protection and error correction, while the RAID controller handles management of the disks and monitors the enclosure. It was hoped that the value of the RAID controller features would offset the additional cost, and that performance would not suffer in this mode. The test results revealed that the hybrid RBOD approach did suffer reduced performance.

  14. Effect of enclosure and nutrient enrichment on Microcystis blooms in Donghu Lake

    Institute of Scientific and Technical Information of China (English)

    TANG Huijuan; XIE Ping; XIE Liqiang; CHEN Feizhou

    2006-01-01

    A nutrient enrichment experiment was conducted in situ in Donghu Lake (30°33′N,114°23′E), a shallow hypereutrophic lake in Hubei, China through an enclosure(each 2.5×2.5m by 2 m depth) method from July 15 to September 21, 2000. Three duplicated groups, including two treatments and one control, were designed as unfertilized control (C), nitrogen enrichment (N) and phosphorus enrichment (P), and were also compared with neighboring lake water. Dense Microcystis bloom exclusively dominated in all the enclosures, while no bloom was observed in the lake. All the enclosures had much higher phytoplankton biomass, higher pH values, and higher transparency than the surrounding lake water. Neither nitrogen nor phosphorus addition had significant effect on phytoplankton composition and biomass due to very high nutrient concentration in the lake water. Suitable biological (absence of filter-feeding silver carp and bighead carp) and physical environment (high transparency, high stability and high pH) associate with saturated nutrient concentration contribute to the nuisance Microcystis bloom in the enclosures.

  15. 16 CFR 1201.40 - Interpretation concerning bathtub and shower doors and enclosures.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Interpretation concerning bathtub and shower... Policy and Interpretation § 1201.40 Interpretation concerning bathtub and shower doors and enclosures. (a) Purpose and background. The purpose of this section is to clarify the scope of the terms “bathtub...

  16. A Mathematical Images Group Model to Estimate the Sound Level in a Close-Fitting Enclosure

    Directory of Open Access Journals (Sweden)

    Michael J. Panza

    2014-01-01

    Full Text Available This paper describes a special mathematical images model to determine the sound level inside a close-fitting sound enclosure. Such an enclosure is defined as the internal air volume defined by a machine vibration noise source at one wall and a parallel reflecting wall located very close to it and acts as the outside radiating wall of the enclosure. Four smaller surfaces define a parallelepiped for the volume. The main reverberation group is between the two large parallel planes. Viewed as a discrete line-type source, the main group is extended as additional discrete line-type source image groups due to reflections from the four smaller surfaces. The images group approach provides a convergent solution for the case where hard reflective surfaces are modeled with absorption coefficients equal to zero. Numerical examples are used to calculate the sound pressure level incident on the outside wall and the effect of adding high absorption to the front wall. This is compared to the result from the general large room diffuse reverberant field enclosure formula for several hard wall absorption coefficients and distances between machine and front wall. The images group method is shown to have low sensitivity to hard wall absorption coefficient value and presents a method where zero sound absorption for hard surfaces can be used rather than an initial hard surface sound absorption estimate or measurement to predict the internal sound levels the effect of adding absorption.

  17. 30 CFR 18.14 - Identification of tested noncertified explosion-proof enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of tested noncertified explosion-proof enclosures. 18.14 Section 18.14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... AND ACCESSORIES General Provisions § 18.14 Identification of tested noncertified...

  18. The Relationship between the Area of Aquaculture Pond and Purification Pond in Water Circulation Aquaculture System%池塘循环水养殖模式下养殖面积与净化面积的配比关系研究

    Institute of Scientific and Technical Information of China (English)

    宋超; 陈家长; 戈贤平; 孟顺龙; 范立民; 胡庚东

    2013-01-01

    The establishment of water circulation aquaculture system realized the hierarchical use of nitrogen,phosphorus and other eutrophic substances in aquaculture wastewater and the recirculation use of water resource.However,no research has been reported on the detailed calculation of the relationship between the area of aquaculture pond and purification pond.In this study,referring to the absorption ability of aquatic plants to pollutants in aquaculture wastewater and pollutant generation and discharge coefficient in aquaculture pond,based on the general rules of water quality management in freshwater aquaculture system,a calculation mode was established to investigate the relationship between the area of aquaculture pond and purification pond in freshwater recirculation aquaculture system,which was feasible to explain related cases and would provide theoretical basis to reduce the economic costs in the construction of water circulation aquaculture system and realize the balance between the ecological benefits and the economic benefits.%池塘循环水养殖模式的构建实现了养殖废水中氮、磷等富营养化物质的分级利用和水资源的循环使用,但此前的研究并没有详细计算养殖面积和净化面积合理的配比关系.通过参照水生植物对养殖尾水中污染物的吸收能力和养殖鱼类的产排污系数,再结合淡水池塘养殖过程中的水质管理的一般规律,给出了淡水池塘循环水养殖模式中养殖池塘面积和净化池塘面积之间配比关系的计算方法.利用该计算方法来解释此前相关的研究实例,也证明是可行的.该计算模型的构建为今后在池塘循环水养殖模式构建中降低经济成本,为最终实现生态效益对经济效益的补偿提供了理论基础.

  19. Major viral diseases affecting fish aquaculture in Spain.

    Science.gov (United States)

    Pérez, S I; Rodríguez, S

    1997-06-01

    The number of viruses isolated from fish has grown in the last few years as a reflection of the increasing interest in fish diseases, particularly those occurring in aquaculture facilities. Of all the described viruses, only a few are considered to be of serious concern and economic importance; they are described in this review, drawing special attention to the four families of viruses (Birnaviridae, Rhabdoviridae, Iridoviridae and Reoviridae) that have been reported in Spanish aquaculture. Infectious pancreatic necrosis virus, a member of the first family, is the most spread virus with a prevalence of 39%. Viral diseases are untreatable and because effective and safe vaccines for fish are not yet commercially available, a great care needs to be exercised when moving fish or eggs from one site or country to another. Some fish health control regulations have been legislated in Europe and USA.

  20. Economic Analysis on Key Challenges for Sustainable Aquaculture Development

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw

    developmental stage. The key challenge in this regard is that the conventional used live feed items, Artemia and rotifers, are nutritionally deficient. Thus, the first main purpose of the thesis is carrying out an economic analysis of the feasibility of commercial production and the use of an alternative live...... challenges that could obstruct its sustainable development, such as a lack of suitable feed, which includes fishmeal, fish oil and live feed, and negative environmental externalities. If the aquaculture industry is to reach its full potential, it must be both environmentally and economically sustainable....... To this end, key challenges should be thoroughly examined to identify sustainable and efficient solutions. Thus, the thesis focuses on two important bottlenecks in the growth of the aquaculture sector—namely, lack of nutritionally suitable live feed items for marine finfish production and negative...

  1. Overview of the application of nucleotide in aquaculture

    Directory of Open Access Journals (Sweden)

    Hoang Do Huu

    2016-10-01

    Full Text Available Although long history application in infant formula, dietary nucleotide supplementation has been used only recently in the evaluation of growth performance, stress and pathogen resistance in aquaculture species. This paper addresses the present knowledge of the use of nucleotide supplemented in the diet for culture species. Research reveals that dietary nucleotide may have significant impact and is recommended to add to the feed of aquatic species to get better performance. However, more studies should also be conducted to have better understandings on dose requirement, duration of application, impact on different life stage and under different environmental stress and pathogens. Further study should also examine the effects of dietary nucleotide supplementation of intestinal microbiota and gut morphology, and immune response of aquaculture species.

  2. Overview of the application of nucleotide in aquaculture

    Institute of Scientific and Technical Information of China (English)

    Hoang Do Huu

    2016-01-01

    Although long history application in infant formula, dietary nucleotide supplementation has been used only recently in the evaluation of growth performance, stress and pathogen resistance in aquaculture species. This paper addresses the present knowledge of the use of nucleotide supplemented in the diet for culture species. Research reveals that dietary nucleotide may have significant impact and is recommended to add to the feed of aquatic species to get better performance. However, more studies should also be conducted to have better understandings on dose requirement, duration of application, impact on different life stage and under different environmental stress and pathogens. Further study should also examine the effects of dietary nucleotide supplementation of intestinal microbiota and gut morphology, and immune response of aquaculture species.

  3. Effects of probiotic Bacillus species in aquaculture – An overview

    Directory of Open Access Journals (Sweden)

    Cristian-Teodor BURUIANĂ

    2014-12-01

    Full Text Available The ingestion of a large amount of certain types of beneficial bacteria can reduce the multiplication and development of pathogenic bacteria in the gut. A “probiotic” is a product that contains live microorganisms which positively influence the host intestinal microbiota by preventing the proliferation of pathogenic bacteria and promoting the growth and development of beneficial bacteria. Bacillus spp. are Gram-positive endospore-forming bacteria with beneficial effects in aquaculture industry. The dietary supplementation of Bacillus spp. in fish culture improved especially growth performance, immune response and the disease resistance of fish against pathogenic bacterial infections. The objective of the current paper is to review the recent published investigations reported in the scientific literature on the use of probiotic Bacillus spp. in aquaculture, focusing on their beneficial effects on the host. This review includes the main effects of Bacillus spp. administration in shrimp culture, carp culture, tilapia culture, and other fish culture.

  4. Liposarcoma in clownfish, Amphiprion ocellaris Cuvier, produced in indoor aquaculture.

    Science.gov (United States)

    Sharon, G; Benharroch, D; Kachko, L; Reis-Hevlin, N; Zilberg, D

    2015-06-01

    Clownfish, Amphiprion ocellaris Cuvier, produced and grown in an experimental indoor aquaculture facility, presented with lipomatous tumours. A total of 14 affected fish were examined. Based on the total number of fish at the aquaculture facility at the time of outbreak of this pathology, the scope of the incident is estimated to be 1 of 300 fish. The tumours were characterized by the presence of mature adipocytes of variable sizes, lipoblasts and by an invasive behaviour, which affected internal organs, muscle, central nervous system and, in one case, an eye. Detailed macroscopic and histopathological features are presented. The suggested diagnosis is that of a well-differentiated liposarcoma, a diagnosis so far never applied to fish. The limited outbreak of the neoplasm lasted a few months in 2011 and did not recur. Possible factors leading to this phenomenon, notably the metastasis, are discussed.

  5. Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

    OpenAIRE

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

    While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lem...

  6. Aquaculture in tropical Mexican lakes and dams: achievements and perspectives

    OpenAIRE

    Carranza, Jorge; Lopez, Martin

    2000-01-01

    Mexico, with highly diverse physiography, geology, soils and climate, is a country with a broad mosaic of aquatic ecosystems within 320 watersheds. This paper presents a brief picture of Mexican fresh waters, the distribution of rainfall and the potential for aquaculture. The main fish species and water bodies, dams and lakes, are highlighted. The country faces problems of surface water shortage which requires better management.

  7. Strategic Review and the Feasibility of Seaweed Aquaculture in Ireland

    OpenAIRE

    Werner, A; Clarke, D.; Kraan, S.

    2004-01-01

    The National Seaweed Forum, commissioned by the Minister for the Marine and Natural Resources in 1999, evaluated the current status of the Irish Seaweed Industry, investigated the potential uses of seaweeds and identified measures to be undertaken for developing the different industrial sectors. Seaweed aquaculture was identified as a key area for the development of the Irish Seaweed Industry to meet growing market demands and to create attractive and high–skilled jobs in peripheral communiti...

  8. Investigation of a novel approach for aquaculture site selection.

    Science.gov (United States)

    Falconer, Lynne; Telfer, Trevor C; Ross, Lindsay G

    2016-10-01

    This study investigated the potential use of two "species distribution models" (SDMs), Mahalanobis Typicality and Maxent, for aquaculture site selection. SDMs are used in ecological studies to predict the spatial distribution of species based on analysis of conditions at locations of known presence or absence. Here the input points are aquaculture sites, rather than species occurrence, thus the models evaluate the parameters at the sites and identify similar areas across the rest of the study area. This is a novel approach that avoids the need for data reclassification and weighting which can be a source of conflict and uncertainty within the commonly used multi-criteria evaluation (MCE) technique. Using pangasius culture in the Mekong Delta, Vietnam, as a case study, Mahalanobis Typicality and Maxent SDMs were evaluated against two models developed using the MCE approach. Mahalanobis Typicality and Maxent assess suitability based on similarity to existing farms, while the MCE approach assesses suitability using optimal values for culture. Mahalanobis Typicality considers the variables to have equal importance whereas Maxent analyses the variables to determine those which influence the distribution of the input data. All of the models indicate there are suitable areas for culture along the two main channels of the Mekong River which are currently used to farm pangasius and also inland in the north and east of the study area. The results show the Mahalanobis Typicality model had more high scoring areas and greater overall similarity than Maxent to the MCE outputs, suggesting, for this case study, it was the most appropriate SDM for aquaculture site selection. With suitable input data, a combined SDM and MCE model would overcome limitations of the individual approaches, allowing more robust planning and management decisions for aquaculture, other stakeholders and the environment.

  9. The role of probiotics in aquaculture in Nigeria - a review

    OpenAIRE

    Kolndadacha, O.D.; Adikwu, I.A.; Okaeme, A.N.; Atiribom, R.Y.; Mohammed, A.; Musa, Y.M.

    2011-01-01

    Aquaculture is beset by many problems especially diseases caused by bacteria as the major deteriorating factors. The use of vaccines and antimicrobial agents have been centered on disease control, but are associated with problems The development of antibiotic resistance among the microorganisms have become a global concern as a result of indiscriminate use of antibiotics. Several alternative suggestions for disease prevention have been on probiotics for its efficacy, low cost, less side effec...

  10. Differential identification of aims and results of formation plans: an application to the Spanish aquaculture

    Directory of Open Access Journals (Sweden)

    María Monserrat Cruz González

    2011-06-01

    Full Text Available The main aims of the formation, related theoretically to the performance of human resources, self-training, information and effectiveness, have been identified as the amount in which the company goes further from knowledge to learning. In this paper three hypotheses applied to the Spanish aquaculture are proposed to model the differential aim follow-up and the achievements of the formation plans. The empirical analysis has been carried out with the data of 99 representative companies of the aquaculture sector. The SPSS 19 statistical program was used for the data analysis. A factor analysis was made by the method of principal components. Eighteen nonparametric tests of Kruskal-Wallis type were applied, as well as 36 chi-squared tests. As a result, three principal components were identified that explain 80% of the variance of the aims: the first one refers to policies of implication of human resources, the second one is relatedto objective circumstances and the third one is associated to dynamism. It was confirmed that the relevance of aims is proportional to the percentage of expense in formation and, specifically, it is greater in suppliers. Finally, significantdifferences in the results of the formation with respect to the reduction of errors were observed, this reduction being greater in fish distribution and production. Significant differences were also observed in the effect of the formation on the motivation of the employee, this being greater in fish suppliers and producers

  11. Comparison of Asian Aquaculture Products by Use of Statistically Supported Life Cycle Assessment.

    Science.gov (United States)

    Henriksson, Patrik J G; Rico, Andreu; Zhang, Wenbo; Ahmad-Al-Nahid, Sk; Newton, Richard; Phan, Lam T; Zhang, Zongfeng; Jaithiang, Jintana; Dao, Hai M; Phu, Tran M; Little, David C; Murray, Francis J; Satapornvanit, Kriengkrai; Liu, Liping; Liu, Qigen; Haque, M Mahfujul; Kruijssen, Froukje; de Snoo, Geert R; Heijungs, Reinout; van Bodegom, Peter M; Guinée, Jeroen B

    2015-12-15

    We investigated aquaculture production of Asian tiger shrimp, whiteleg shrimp, giant river prawn, tilapia, and pangasius catfish in Bangladesh, China, Thailand, and Vietnam by using life cycle assessments (LCAs), with the purpose of evaluating the comparative eco-efficiency of producing different aquatic food products. Our starting hypothesis was that different production systems are associated with significantly different environmental impacts, as the production of these aquatic species differs in intensity and management practices. In order to test this hypothesis, we estimated each system's global warming, eutrophication, and freshwater ecotoxicity impacts. The contribution to these impacts and the overall dispersions relative to results were propagated by Monte Carlo simulations and dependent sampling. Paired testing showed significant (p production systems in the intraspecies comparisons, even after a Bonferroni correction. For the full distributions instead of only the median, only for Asian tiger shrimp did more than 95% of the propagated Monte Carlo results favor certain farming systems. The major environmental hot-spots driving the differences in environmental performance among systems were fishmeal from mixed fisheries for global warming, pond runoff and sediment discards for eutrophication, and agricultural pesticides, metals, benzalkonium chloride, and other chlorine-releasing compounds for freshwater ecotoxicity. The Asian aquaculture industry should therefore strive toward farming systems relying upon pelleted species-specific feeds, where the fishmeal inclusion is limited and sourced sustainably. Also, excessive nutrients should be recycled in integrated organic agriculture together with efficient aeration solutions powered by renewable energy sources.

  12. Computational fluid dynamics modeling of mixed convection flows in buildings enclosures

    Directory of Open Access Journals (Sweden)

    Alexander Kayne, Ramesh K. Agarwal

    2013-01-01

    Full Text Available In recent years Computational Fluid Dynamics (CFD simulations are increasingly used to model the air circulation and temperature environment inside the rooms of residential and office buildings to gain insight into the relative energy consumptions of various HVAC systems for cooling/heating for climate control and thermal comfort. This requires accurate simulation of turbulent flow and heat transfer for various types of ventilation systems using the Reynolds-Averaged Navier-Stokes (RANS equations of fluid dynamics. Large Eddy Simulation (LES or Direct Numerical Simulation (DNS of Navier-Stokes equations is computationally intensive and expensive for simulations of this kind. As a result, vast majority of CFD simulations employ RANS equations in conjunction with a turbulence model. In order to assess the modeling requirements (mesh, numerical algorithm, turbulence model etc. for accurate simulations, it is critical to validate the calculations against the experimental data. For this purpose, we use three well known benchmark validation cases, one for natural convection in 2D closed vertical cavity, second for forced convection in a 2D rectangular cavity and the third for mixed convection in a 2D square cavity. The simulations are performed on a number of meshes of different density using a number of turbulence models. It is found that k-epsilon two-equation turbulence model with a second-order algorithm on a reasonable mesh gives the best results. This information is then used to determine the modeling requirements (mesh, numerical algorithm, turbulence model etc. for flows in 3D enclosures with different ventilation systems. In particular two cases are considered for which the experimental data is available. These cases are (1 air flow and heat transfer in a naturally ventilated room and (2 airflow and temperature distribution in an atrium. Good agreement with the experimental data and computations of other investigators is obtained.

  13. Computational fluid dynamics modeling of mixed convection flows in buildings enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Kayne, Alexander; Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

    2013-07-01

    In recent years Computational Fluid Dynamics (CFD) simulations are increasingly used to model the air circulation and temperature environment inside the rooms of residential and office buildings to gain insight into the relative energy consumptions of various HVAC systems for cooling/heating for climate control and thermal comfort. This requires accurate simulation of turbulent flow and heat transfer for various types of ventilation systems using the Reynolds-Averaged Navier-Stokes (RANS) equations of fluid dynamics. Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) of Navier-Stokes equations is computationally intensive and expensive for simulations of this kind. As a result, vast majority of CFD simulations employ RANS equations in conjunction with a turbulence model. In order to assess the modeling requirements (mesh, numerical algorithm, turbulence model etc.) for accurate simulations, it is critical to validate the calculations against the experimental data. For this purpose, we use three well known benchmark validation cases, one for natural convection in 2D closed vertical cavity, second for forced convection in a 2D rectangular cavity and the third for mixed convection in a 2D square cavity. The simulations are performed on a number of meshes of different density using a number of turbulence models. It is found that k-epsilon two-equation turbulence model with a second-order algorithm on a reasonable mesh gives the best results. This information is then used to determine the modeling requirements (mesh, numerical algorithm, turbulence model etc.) for flows in 3D enclosures with different ventilation systems. In particular two cases are considered for which the experimental data is available. These cases are (1) air flow and heat transfer in a naturally ventilated room and (2) airflow and temperature distribution in an atrium. Good agreement with the experimental data and computations of other investigators is obtained.

  14. Chryseobacterium chengduensis sp. nov. isolated from the air of captive giant panda enclosures in Chengdu, China.

    Science.gov (United States)

    Wen, Cai-Fang; Xi, Li-Xin; Zhao, Shan; Hao, Zhong-Xiang; Luo, Lu; Liao, Hong; Chen, Zhen-Rong; She, Rong; Han, Guo-Quan; Cao, San-Jie; Wu, Rui; Yan, Qi-Gui; Hou, Rong

    2016-08-01

    A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated 25-1(T), was isolated from the air inside giant panda enclosures at the Chengdu Research Base of Giant Panda Breeding, China. Strain 25-1(T) grew optimally at pH 7.0-8.0, at 28-30 °C and in the presence of NaCl concentrations from 0.0% to 0.5 %. 16S rRNA gene sequence analysis indicated that strain 25-1(T) belongs to the genus Chryseobacterium within the family Flavobacteriaceae and is related most closely to C. carnis G81(T) (96.4% similarity), C. lathyri RBA2-6(T) (95.8% similarity), and C. zeae JM1085(T) (95.8% similarity). Its genomic DNA G+C molar composition was 36.2%. The major cellular fatty acids were iso-C15:0 (44.0%), iso-C17:0 3OH (19.8%) and C16:1 ω7c/16:1 ω6c (12.7%). The only isoprenoid quinone was menaquinone 6 (MK-6). The major polar lipids were phosphatidylethanolamine, two unidentified amino lipids and two unidentified lipids. The DNA-DNA relatedness between strain 25-1(T) and C. lathyri RBA2-6(T) was 38%. Phenotypic, genotypic, and phylogenetic characteristics indicated that strain 25-1(T) is a novel member of the genus Chryseobacterium, for which the name C. chengduensis sp. nov. is proposed. The type strain is 25-1(T) (CCTCC AB2015133(T)=DSM 100396(T)).

  15. Numerical investigation of natural convection in two enclosures separated by anisotropic solid wall

    KAUST Repository

    Salama, Amgad

    2014-10-28

    Purpose: The problem of natural convection in two cavities separated by an anisotropic central solid wall is considered numerically. When the thermal conductivity of the central wall is anisotropic, heat flux and temperature gradient vectors are no longer coincidence. This apparently has interesting influences on the heat and fluid flow patterns in this system. The paper aims to discuss these issues.Design/methodology/approach: In this work, several flow patterns have been investigated covering a wide range of Rayleigh number up to 108. Several thermal conductivity anisotropy scenarios of the central wall have been investigated including 0, 30, 60, 120 and 1501 principal anisotropy directions. The governing equations have been solved using control volume approach.Findings: Probably the most intriguing is that, for some anisotropy scenarios it is found that the temperature at the same elevation at the side of the central wall which is closer to the colder wall is higher than that at the side closer to the hot wall. Apparently this defies intuition which suggests the reverse to have happened. However, this behavior may be explained in light of the effect of anisotropy. Furthermore, the patterns of streamlines and temperature fields in the two enclosures also changes as a consequence of the change of the central wall temperatures for the different anisotropy scenarios.Originality/value: This work discusses a very interesting topic related to heat energy exchange among two compartments when the separating wall is anisotropic. In some anisotropy scenarios, this leads to more uniform distribution of Nusselt number than the case when the wall is isotropic. Interesting patterns of natural convection is investigated.

  16. Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures.

    Science.gov (United States)

    Gress, J; da Silva, E B; de Oliveira, L M; Zhao, Di; Anderson, G; Heard, D; Stuchal, L D; Ma, L Q

    2016-05-01

    Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0-110mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6-111μg/100cm(2), typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22-7.8μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals.

  17. Effects of repeated exposure to 4-nonylphenol on the zooplankton community in littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    O`Halloran, S.L.; Liber, K.; Gangl, J.A. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Knuth, M.L. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1999-03-01

    The effects of 4-nonylphenol (NP) on freshwater zooplankton were evaluated in 18 littoral enclosure mesocosms in northeastern Minnesota. The 18 enclosures were allocated to three blocks of six units with each block including two untreated control enclosures and one enclosure for each of four NP treatments. Treated enclosures received 11 applications of NP over a 20-d period between July 8 and 28, 1993. Maximum NP concentrations measured in the water column 2 h after each application averaged ({+-} SD) 5 {+-} 4, 23 {+-} 11, 76 {+-} 21, and 243 {+-} 41 {micro}g/L over the 11 applications. Nonylphenol dissipated rapidly from the water column but was more persistent in sediments and in/on macrophytes. All cladoceran and copepod taxa were significantly reduced in abundance at 243 {+-} 41 {micro}g/L; some sensitive taxa were also affected by 76 {+-} 21 and 23 {+-} 11 {micro}g/L. While many rotifer taxa were unaffected at any of the test concentrations, several were affected at {ge} 76 {+-} 21 {micro}g/L. Ostracods were only affected at 2,243 {+-} 41 {micro}g/L. No zooplankton taxon was affected at 5 {+-} 4 {micro}g/L. The period of maximum impact usually occurred within 1 to 7 d of the last NP application, and recovery to control abundance levels generally occurred within 7 to 28 d of the last NP application. Two sensitive taxa, Acroperus and Calanoida, did not recover at {ge} 76 {+-} 21 {micro}g/L by the end of the study. The maximum acceptable toxicant concentration for protection of all zooplankton taxa was estimated at {approximately} 10 {micro}g/L, although overall community diversity was unaffected at 23 {+-} 11. The water was the most probable route of NP exposure, but the greater persistence of NP residues in/on macrophytes may have contributed to the lack of recovery of some macrophyte-associated taxa.

  18. Taurine and fish development: insights for the aquaculture industry.

    Science.gov (United States)

    Pinto, Wilson; Rønnestad, Ivar; Dinis, Maria Teresa; Aragão, Cláudia

    2013-01-01

    Expansion of the aquaculture industry is limited by incomplete knowledge on fish larval nutritional requirements. Nevertheless, it is believed that dietary taurine deficiencies may be particularly critical for fish larvae. The reasons include the high taurine levels found during egg and yolk-sac stages of fish, suggesting that taurine may be of pivotal importance for larval development. Moreover, unlike aquaculture feeds, natural preys of fish larvae contain high taurine levels, and dietary taurine supplementation has been shown to increase larval growth in several fish species. This study aimed to further explore the physiological role of taurine during fish development. Firstly, the effect of dietary taurine supplementation was assessed on growth of gilthead sea bream (Sparus aurata) larvae and growth, metamorphosis success and amino acid metabolism of Senegalese sole (Solea senegalensis) larvae. Secondly, the expression of taurine transporter (TauT) was characterised by qPCR in sole larvae and juveniles. Results showed that dietary taurine supplementation did not increase sea bream growth. However, dietary taurine supplementation significantly increased sole larval growth, metamorphosis success and amino acid retention. Metamorphosis was also shown to be an important developmental trigger to promote taurine transport in sole tissues, while evidence for an enterohepatic recycling pathway for taurine was found in sole at least from juvenile stage. Taken together, our studies showed that the dependence of dietary taurine supplementation differs among fish species and that taurine has a vital role during the ontogenetic development of flatfish, an extremely valuable group targeted for aquaculture production.

  19. Coastal Aquaculture Development in Bangladesh: Unsustainable and Sustainable Experiences

    Science.gov (United States)

    Azad, A. Kalam; Jensen, Kathe R.; Lin, C. Kwei

    2009-10-01

    Coastal aquaculture in Bangladesh consists mainly of two shrimp species ( Penaeus monodon and Macrobrachium rosenbergii). Currently, there are about 16,237 marine shrimp ( P. monodon) farms covering 148,093 ha and 36,109 fresh water shrimp ( M. rosenbergii) farms covering 17,638 ha coastal area. More than 0.7 million people are employed in the farmed shrimp sector and in 2005-2006 the export value of shrimp was 403.5 million USD. Thus, coastal aquaculture contributes significantly to rural employment and economy but this is overshadowed by negative social and ecological impacts. This article reviews the key issues, constraints and opportunities of sustainable shrimp farming. In addition we present the results of two case studies from southwestern coastal areas where shrimp farming originated and central coastal areas where shrimp farming, especially M. rosenbergii, began in recent years. Lessons learned from the review and case studies are considered in the context of recommendations to encompass a socially equitable and ecologically sound coastal aquaculture.

  20. Research on China's Aquaculture Efficiency Evaluation and Influencing Factors with Undesirable Outputs

    Institute of Scientific and Technical Information of China (English)

    JI Jianyue; WANG Pingping

    2015-01-01

    Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology ex-tension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that tech-nology extension factor and technical level factor have significant positive influence.

  1. Towards sustainable coexistence of aquaculture and fisheries in the coastal zone

    DEFF Research Database (Denmark)

    Bergh, Øjvind; Gomez, Emma Bello; Børsheim, Knut Yngve;

    2012-01-01

    Globally, coastal areas are subject to an increase in competing activities. Coastal fisheries and aquaculture are highly dependent on availability and accessibility of appropriate sites. Aquaculture production is increasing, whereas fisheries are at best stagnant. Coastal activities also include ......, both industries represent human activities strongly influencing, and influenced by, the environment. Management of aquaculture and fisheries, as well as other uses of the coastal zone, should be considered integral parts with local variations in their respective importance.......Globally, coastal areas are subject to an increase in competing activities. Coastal fisheries and aquaculture are highly dependent on availability and accessibility of appropriate sites. Aquaculture production is increasing, whereas fisheries are at best stagnant. Coastal activities also include...... ecosystem‐based management as demanded by the Marine Strategy Directive. The biological interconnectedness of fisheries and aquaculture is strong, with factors such as competition for space, disease transmission, genetic impact from escapees, availability of food for cultured finfish, and organic...

  2. Denitrification and anammox in tropical aquaculture settlement ponds: an isotope tracer approach for evaluating N2 production.

    Directory of Open Access Journals (Sweden)

    Sarah A Castine

    Full Text Available Settlement ponds are used to treat aquaculture discharge water by removing nutrients through physical (settling and biological (microbial transformation processes. Nutrient removal through settling has been quantified, however, the occurrence of, and potential for microbial nitrogen (N removal is largely unknown in these systems. Therefore, isotope tracer techniques were used to measure potential rates of denitrification and anaerobic ammonium oxidation (anammox in the sediment of settlement ponds in tropical aquaculture systems. Dinitrogen gas (N(2 was produced in all ponds, although potential rates were low (0-7.07 nmol N cm(-3 h(-1 relative to other aquatic systems. Denitrification was the main driver of N(2 production, with anammox only detected in two of the four ponds. No correlations were detected between the measured sediment variables (total organic carbon, total nitrogen, iron, manganese, sulphur and phosphorous and denitrification or anammox. Furthermore, denitrification was not carbon limited as the addition of particulate organic matter (paired t-Test; P = 0.350, n = 3 or methanol (paired t-Test; P = 0.744, n = 3 did not stimulate production of N(2. A simple mass balance model showed that only 2.5% of added fixed N was removed in the studied settlement ponds through the denitrification and anammox processes. It is recommended that settlement ponds be used in conjunction with additional technologies (i.e. constructed wetlands or biological reactors to enhance N(2 production and N removal from aquaculture wastewater.

  3. Monte Carlo simulation of radiation heat transfer in a three-dimensional enclosure containing a circular cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.H.; Welty, J.R.

    1999-09-01

    In any process involving high temperatures such as heat treatment, power generation, and other engineering applications, radiation heat transfer is an important mechanism. This paper presents the distribution of radiation heat flux within an enclosure containing a horizontal circular cylinder. Cases were examined both with and without an absorbing, emitting, and scattering medium present. The bottom surface of the square enclosure was considered a uniform heat flux surface, and the other surfaces were considered perfectly absorbing. A circular cylinder was located at various positions along the vertical centerline of the enclosure; its length was that of the enclosure depth. In the first part of this study (cases 1 and 2), different configurations were used with an optically thin ({tau} {much{underscore}lt} 1) medium in the enclosure, and in the second, different optical thicknesses were used with a fixed enclosure size. The amount of radiant energy transferred to the cylinder depends on its location, the optical thickness of the participating medium, and the enclosure depth. For the optically thin cases ({tau} {much{underscore}lt} 1) the Monte Carlo solution calculates geometric view factors.

  4. Analysis of the development of global capture fishery and aquaculture production

    OpenAIRE

    Algayd, Abdelhamid Alhadi

    2011-01-01

    Global production from capture fisheries and aquaculture and the food fish supply is currently the highest on record and remains very significant for global food security. This study is focused on the contribution of the aquaculture to the global production of fish, crustaceans, molluscs, and other aquatic animals in the short-time observation from 2000- 2008. The aim of the presented PhD. Thesis title "Analysis of The Development of Global Capture Fish and Aquaculture Production (200-2008)" ...

  5. Tracing dissolved organic matter (DOM) from land-based aquaculture systems in North Patagonian streams.

    Science.gov (United States)

    Nimptsch, Jorge; Woelfl, Stefan; Osorio, Sebastian; Valenzuela, Jose; Ebersbach, Paul; von Tuempling, Wolf; Palma, Rodrigo; Encina, Francisco; Figueroa, David; Kamjunke, Norbert; Graeber, Daniel

    2015-12-15

    Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradability are unknown. The aim of this study was thus to investigate the inputs of anthropogenic DOM from land-based aquaculture to the predominantly pristine river systems of North Patagonia. We hypothesized, that i) DOM exported from land-based aquaculture mainly consists of protein-like fluorescence (tyrosine and tryptophan) released from fish feces and food remains, and that ii) this DOM is highly degradable and therefore rapidly turned-over within the receiving streams. In the North Patagonian region we conducted a screening of ten land-based aquacultures and an intensive sampling campaign for one aquaculture. This was combined with longitudinal transects and a degradation experiment in order to couple the composition of DOM exported from land-based aquacultures to its degradability in streams. We measured dissolved organic carbon (DOC) concentration by high-temperature catalytic oxidation and DOM composition by fluorescence spectroscopy and parallel factor analysis. In the effluent of the ten screened aquacultures and in the repeated sampling of one aquaculture, we consistently found an increase of DOC concentrations and a dominance of protein-like fluorescence. The protein-like fluorescence rapidly disappeared downstream of the aquacultures, and in the degradation experiment. 21% of the DOC export from the repeatedly sampled aquaculture resulted from food addition and 76% from fish production. We conclude that large amounts of degradable DOM are exported from land-based aquacultures. This probably has strong effects on the ecological structure and function of North Patagonian streams, and similarly affected streams worldwide.

  6. Feeding ecology of penaeid shrimp in Kenyan mangrove ecosystems: implications for biological shrimp aquaculture

    OpenAIRE

    Gatune, W.C.

    2013-01-01

    Ecological shrimp aquaculture derives its feed input from the naturally occurring food sources. This practice has an environmental advantage of reducing the use of fish meal as the main food input. Use of fish meal in aquaculture has a negative effect on the coastal fisheries in the sense of depleting fish stocks. It also has a tendency to discharge wastes that pollutes the receiving coastal ecosystems. Ecological shrimp aquaculture therefore impacts low burden to the coastal ecosystems since...

  7. Life Cycle Assessment for environmentally sustainable aquaculture management : a case study of combined aquaculture systems for carp and tilapia

    OpenAIRE

    2013-01-01

    Life Cycle Assessment (LCA) was applied to evaluate the potential environmental impacts associated with two-net cage aquaculture systems of common carp (Cyprinus carpio carpio) and tilapia (Oreochromis niloticus) in the Cirata reservoir, Indonesia. The studied system included fingerling production in hatcheries, fish rearing in cages, and transport of fry and feed as well as that of harvested fish to markets. The environmental impact indicators were calculated based on the annual production i...

  8. Land-based salmon aquacultures change the quality and bacterial degradation of riverine dissolved organic matter

    Science.gov (United States)

    Kamjunke, Norbert; Nimptsch, Jorge; Harir, Mourad; Herzsprung, Peter; Schmitt-Kopplin, Philippe; Neu, Thomas R.; Graeber, Daniel; Osorio, Sebastian; Valenzuela, Jose; Carlos Reyes, Juan; Woelfl, Stefan; Hertkorn, Norbert

    2017-03-01

    Aquacultures are of great economic importance worldwide but pollute pristine headwater streams, lakes, and estuaries. However, there are no in-depth studies of the consequences of aquacultures on dissolved organic matter (DOM) composition and structure. We performed a detailed molecular level characterization of aquaculture DOM quality and its bacterial degradation using four salmon aquacultures in Chile. Fluorescence measurements, ultrahigh-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy of the DOM revealed specific and extensive molecular alterations caused by aquacultures. Aquacultures released large quantities of readily bioavailable metabolites (primarily carbohydrates and peptides/proteins, and lipids), causing the organic matter downstream of all the investigated aquacultures to deviate strongly from the highly processed, polydisperse and molecularly heterogeneous DOM found in pristine rivers. However, the upstream individual catchment DOM signatures remained distinguishable at the downstream sites. The benthic algal biovolume decreased and the bacterial biovolume and production increased downstream of the aquacultures, shifting stream ecosystems to a more heterotrophic state and thus impairing the ecosystem health. The bacterial DOM degradation rates explain the attenuation of aquaculture DOM within the subsequent stream reaches. This knowledge may aid the development of improved waste processing facilities and may help to define emission thresholds to protect sensitive stream ecosystems.

  9. Environmental impact of non-certified versus certified (ASC) intensive Pangasius aquaculture in Vietnam, a comparison based on a statistically supported LCA.

    Science.gov (United States)

    Nhu, Trang T; Schaubroeck, Thomas; Henriksson, Patrik J G; Bosma, Roel; Sorgeloos, Patrick; Dewulf, Jo

    2016-12-01

    Pangasius production in Vietnam is widely known as a success story in aquaculture, the fastest growing global food system because of its tremendous expansion by volume, value and the number of international markets to which Pangasius has been exported in recent years. While certification schemes are becoming significant features of international fish trade and marketing, an increasing number of Pangasius producers have followed at least one of the certification schemes recognised by international markets to incorporate environmental and social sustainability practices in aquaculture, typically the Pangasius Aquaculture Dialogue (PAD) scheme certified by the Aquaculture Stewardship Council (ASC). An assessment of the environmental benefit of applying certification schemes on Pangasius production, however, is still needed. This article compared the environmental impact of ASC-certified versus non-ASC certified intensive Pangasius aquaculture, using a statistically supported LCA. We focused on both resource-related (water, land and total resources) and emissions-related (global warming, acidification, freshwater and marine eutrophication) categories. The ASC certification scheme was shown to be a good approach for determining adequate environmental sustainability, especially concerning emissions-related categories, in Pangasius production. However, the non-ASC certified farms, due to the large spread, the impact (e.g., water resources and freshwater eutrophication) was possibly lower for a certain farm. However, this result was not generally prominent. Further improvements in intensive Pangasius production to inspire certification schemes are proposed, e.g., making the implementation of certification schemes more affordable, well-oriented and facilitated; reducing consumed feed amounts and of the incorporated share in fishmeal, especially domestic fishmeal, etc. However, their implementation should be vetted with key stakeholders to assess their feasibility.

  10. Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

    Directory of Open Access Journals (Sweden)

    Xingguo Liu

    Full Text Available Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis and silver carp (Hypophthalmichthys molitrix culture ponds using the SMWM resulted in decreased NH3(+-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These

  11. Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture.

    Science.gov (United States)

    Liu, Xingguo; Xu, Hao; Ma, Zhuojun; Zhang, Yongjun; Tian, Changfeng; Cheng, Guofeng; Zou, Haisheng; Lu, Shimin; Liu, Shijing; Tang, Rong

    2016-01-01

    Bream pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM) was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water's surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine's motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine's mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02-0.03 m/s. For an illumination of 13,000-52,500 Lx, the sediment lifting device runs at 0.13-0.35 m/s, and its water delivery capacity is 110-208 m(3)/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10-15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis) and silver carp (Hypophthalmichthys molitrix) culture ponds using the SMWM resulted in decreased NH3(+)-N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These results

  12. Potential arsenic exposures in 25 species of zoo animals living in CCA-wood enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Gress, J. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Silva, E.B. da; Oliveira, L.M. de [Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States); Zhao, Di [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Anderson, G. [Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Heard, D. [Department of Small Animal Clinical Sciences, University of Florida, Gainesville, FL 32610 (United States); Stuchal, L.D. [Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32611 (United States); Ma, L.Q., E-mail: lqma@ufl.edu [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States)

    2016-05-01

    Animal enclosures are often constructed from wood treated with the pesticide chromated copper arsenate (CCA), which leaches arsenic (As) into adjacent soil during normal weathering. This study evaluated potential pathways of As exposure in 25 species of zoo animals living in CCA-wood enclosures. We analyzed As speciation in complete animal foods, dislodgeable As from CCA-wood, and As levels in enclosure soils, as well as As levels in biomarkers of 9 species of crocodilians (eggs), 4 species of birds (feathers), 1 primate species (hair), and 1 porcupine species (quills). Elevated soil As in samples from 17 enclosures was observed at 1.0–110 mg/kg, and enclosures housing threatened and endangered species had As levels higher than USEPA's risk-based Eco-SSL for birds and mammals of 43 and 46 mg/kg. Wipe samples of CCA-wood on which primates sit had dislodgeable As residues of 4.6–111 μg/100 cm{sup 2}, typical of unsealed CCA-wood. Inorganic As doses from animal foods were estimated at 0.22–7.8 μg/kg bw/d. Some As levels in bird feathers and crocodilian eggs were higher than prior studies on wild species. However, hair from marmosets had 6.37 mg/kg As, 30-fold greater than the reference value, possibly due to their inability to methylate inorganic As. Our data suggested that elevated As in soils and dislodgeable As from CCA-wood could be important sources of As exposure for zoo animals. - Highlights: • Daily inorganic As dose from zoo animal foods was 0.22–7.8 μg/kg bw/day. • Total As concentrations in soils of zoo animal enclosures were 1.0–110 mg/kg. • Endangered zoo animals live in soils with As above USEPA Eco-SSLs for avian and mammal species. • Dislodgeable As on CCA-wood beams where primates sit was 4.6–111 μg/100 cm{sup 2}. • Marmoset hair had 6.37 mg/kg As compared to a reference value of 0.21 mg/kg.

  13. 连阴雨天气对凡纳滨对虾-吉丽罗非鱼混养围隔中浮游植物和对虾生长、存活的影响%Effects of Continuous Rainy Weather on Phytoplankton and the Growth and Survival of Shrimp in Litopenaeus vannamei-Gili Tilapia Polyculture Enclosures

    Institute of Scientific and Technical Information of China (English)

    林丽华; 粟丽; 朱长波; 张汉华

    2012-01-01

    [Objective] The research aimed to provide some theoretical basis for Litopenaeus vannamei-Gili tilapia polyculture. [ Method] The effects of continuous rainy weather on the growth and survival of phytoplankton and shrimp in the culture enclosure of L. vannamei were studied. [ Result] The continuous rainy weather had the effects on the number and dominant species of phytoplankton in the enclosures. The number of phytoplankton in all enclosures declined and reached the lowest value on July 20th , and the dominant species changed from Cyanobacte-ria to Chlorophyta. Because of continuous rainy weather, dead shrimps appeared in half of Enclosures on about July 10th. From July 10th to July 23rd , pH and dissolved oxygen in the enclosures decreased, and the content of ammonia nitrogen and nitrite increased. The changes of these environmental factors were harmful to the growth of shrimp. [Conclusion] Continuous rainy weather influenced the temperature, pH, ammonia nitrogen, nitrite nitrogen and other physical and chemical factors of phytoplankton and water, which caused the environmental fluctuations of aquaculture water and resulted in the occurrence of shrimp diseases.%[目的]为凡纳滨对虾-吉丽罗非鱼混养提供一定的理论依据.[方法]探讨连续阴雨天气对凡纳滨对虾养殖围隔中浮游植物和对虾生长、存活的影响.[结果]连阴雨天气对围隔中浮游植物的数量和优势种都有影响,使各围隔浮游植物数量下降,在7月20日降至最低,优势种从蓝藻转变为绿藻.连续阴雨天气使半数围隔在7月10日左右出现了死虾情况;7月10日至7月23日各围隔pH、溶解氧均有所降低,氨氮和亚硝酸盐含量有所上升,这些环境因子的突变不利于对虾的生长.[结论]连阴雨天气通过影响浮游植物和水体温度、pH、氨氮、亚硝氮等理化因子,引起的养殖水体环境波动,从而导致对虾病害的发生.

  14. Probabilistic risk assessment of veterinary medicines applied to four major aquaculture species produced in Asia.

    Science.gov (United States)

    Rico, Andreu; Van den Brink, Paul J

    2014-01-15

    Aquaculture production constitutes one of the main sources of pollution with veterinary medicines into the environment. About 90% of the global aquaculture production is produced in Asia and the potential environmental risks associated with the use of veterinary medicines in Asian aquaculture have not yet been properly evaluated. In this study we performed a probabilistic risk assessment for eight different aquaculture production scenarios in Asia by combining up-to-date information on the use of veterinary medicines and aquaculture production characteristics. The ERA-AQUA model was used to perform mass balances of veterinary medicinal treatments applied to aquaculture ponds and to characterize risks for primary producers, invertebrates, and fish potentially exposed to chemical residues through aquaculture effluents. The mass balance calculations showed that, on average, about 25% of the applied drug mass to aquaculture ponds is released into the environment, although this percentage varies with the chemical's properties, the mode of application, the cultured species density, and the water exchange rates in the aquaculture pond scenario. In general, the highest potential environmental risks were calculated for parasitic treatments, followed by disinfection and antibiotic treatments. Pangasius catfish production in Vietnam, followed by shrimp production in China, constitute possible hot-spots for environmental pollution due to the intensity of the aquaculture production and considerable discharge of toxic chemical residues into surrounding aquatic ecosystems. A risk-based ranking of compounds is provided for each of the evaluated scenarios, which offers crucial information for conducting further chemical and biological field and laboratory monitoring research. In addition, we discuss general knowledge gaps and research priorities for performing refined risk assessments of aquaculture medicines in the near future.

  15. Modeling and Eigenfrequency Analysis of Sound-Structure Interaction in a Rectangular Enclosure with Finite Element Method

    Directory of Open Access Journals (Sweden)

    Samira Mohamady

    2009-01-01

    Full Text Available Vibration of structures due to external sound is one of the main causes of interior noise in cavities like automobile, aircraft, and rotorcraft, which disturb the comfort of passengers. Accurate modelling of such phenomena is required in eigenfrequency analysis and in designing an active noise control system to reduce the interior noise. In this paper, the effect of periodic noise travelling into a rectangular enclosure is investigated with finite element method (FEM using COMSOL Multiphysics software. The periodic acoustic wave is generated by a point source outside the enclosure and propagated through the enclosure wall and excites an aluminium flexible panel clamped onto the enclosure. The behaviour of the transmission of sound into the cavity is investigated by computing the modal characteristics and the natural frequencies of the cavity. The simulation results are compared with previous analytical and experimental works for validation and an acceptable match between them were obtained.

  16. On the Use of Computer Algebra Systems and Enclosure Methods in the Modelling and Optimization of Biotechnological Processes

    Directory of Open Access Journals (Sweden)

    Svetoslav Markov

    2005-12-01

    Full Text Available This survey paper aims to promote certain novel mathematical tools, such as computer algebra systems, enclosure methods and interval analysis, to the mathematical modelling and optimization of biotechnological processes.

  17. RELAP5-3D multidimensional heat conduction enclosure model for RBMK reactor application

    Energy Technology Data Exchange (ETDEWEB)

    Paik, S.

    1999-10-01

    A heat conduction enclosure model is conceived and implemented by RELAP5-3D between heat structures. The suggested model uses a lumped parameter model that is generally applicable to multidimensional calculational domain. This new model is applied to calculation of RBMK reactor core graphite blocks and is compared to the commercially available Fluid Dynamics Analysis Package (FIDAP) finite element code. Reasonably good agreement between the results of RELAP5-3D and FIDAP is obtained. The new heat conduction enclosure model gives RELAP5-3D a general multidimensional heat conduction capability. It also provides new routes for temperature cooloff of the RBMK graphite blocks from the ruptured channel to the surrounding ones. This ability to predict graphite temperature cooloff is very important during accidents or for transient simulation, especially concerning long-term coolability of the RBMK reactor core.

  18. Influence of a strong magnetic field on paramagnetic fluid's flow in cubical enclosure

    Science.gov (United States)

    Kraszewska, A.; Pyrda, L.; Donizak, J.

    2016-10-01

    The fluid behaviour in thermo-magnetic convection of paramagnetic fluid in a strong magnetic field was studied. The fluid was 50% volume aqueous solution of glycerol with an addition of gadolinium nitrate hexahydrate (Gd(NO3)3-6H2O). Experimental enclosure - a vessel with aspect ratio (AR=height/width) equal to 1.0 - was heated from the bottom, and cooled from the top. Temperature difference between top and bottom walls was kept constant at ΔT = 5 and 11 [°C]. The magnetic induction was increased stepwise from 1 to 10 [T] and thermocouples placed inside the enclosures measured temperature changes of the fluid. On the basis of temperature measurements, analysis of the fluid flow was performed.

  19. GMT site, enclosure, and facilities design and development overview and update

    Science.gov (United States)

    Teran, Jose; Burgett, William S.; Grigel, Eric; Bigelow, Bruce C.; Donoso, Eduardo; Figueroa, Francisco

    2016-07-01

    The Giant Magellan Telescope (GMT) will have a 25.4-meter diameter effective aperture, and is one the three currently planned next generation extremely large telescopes (ELTs). The GMT will be located at the summit of Cerro Campanas at the Las Campanas Observatory (LCO) in Chile, one the world's best observing sites. This paper provides an overview of the site master plan comprising site infrastructure, enclosure, and facilities, and outlines the analysis of alternative trade studies that will lead to the final design. Also presented is an update of the site infrastructure development and preconstruction activities currently underway that will be completed prior to the beginning of enclosure construction near the end of 2016.

  20. A Bayesian Approach to the Orientations of Central Alentejo Megalithic Enclosures

    Science.gov (United States)

    Pimenta, Fernando; Tirapicos, Luís; Smith, Andrew

    2009-12-01

    In this work we have conducted a study on the orientations in the landscape of twelve megalithic enclosures in the Alentejo region of southern Portugal. Some of these sites date back to the sixth or fifth millennium B.C. and are among the oldest stone enclosures in Europe. The results of the survey show a pattern toward eastern rising orientations. We used dedicated GIS software from one of the authors to produce horizon profiles and applied a statistical Bayesian approach in an attempt to check how the data would fit to different models. In particular, we tested our results for a possible ritual interest in the Autumn or Harvest Full Moon and discuss previous studies by Michael Hoskin and colleges on the orientations of seven stone dolmens of this area that have shown the existence of a possible custom for an orientation toward the sunrise.

  1. Canonical Statistical Model for Maximum Expected Immission of Wire Conductor in an Aperture Enclosure

    Science.gov (United States)

    Bremner, Paul G.; Vazquez, Gabriel; Christiano, Daniel J.; Trout, Dawn H.

    2016-01-01

    Prediction of the maximum expected electromagnetic pick-up of conductors inside a realistic shielding enclosure is an important canonical problem for system-level EMC design of space craft, launch vehicles, aircraft and automobiles. This paper introduces a simple statistical power balance model for prediction of the maximum expected current in a wire conductor inside an aperture enclosure. It calculates both the statistical mean and variance of the immission from the physical design parameters of the problem. Familiar probability density functions can then be used to predict the maximum expected immission for deign purposes. The statistical power balance model requires minimal EMC design information and solves orders of magnitude faster than existing numerical models, making it ultimately viable for scaled-up, full system-level modeling. Both experimental test results and full wave simulation results are used to validate the foundational model.

  2. Generalization of a 3-D Acoustic Resonator Model for the Simulation of Spherical Enclosures

    Directory of Open Access Journals (Sweden)

    Dutilleux Pierre

    2001-01-01

    Full Text Available A rectangular enclosure has such an even distribution of resonances that it can be accurately and efficiently modelled using a feedback delay network. Conversely, a nonrectangular shape such as a sphere has a distribution of resonances that challenges the construction of an efficient model. This work proposes an extension of the already known feedback delay network structure to model the resonant properties of a sphere. A specific frequency distribution of resonances can be approximated, up to a certain frequency, by inserting an allpass filter of moderate order after each delay line of a feedback delay network. The structure used for rectangular boxes is therefore augmented with a set of allpass filters allowing parametric control over the enclosure size and the boundary properties. This work was motivated by informal listening tests which have shown that it is possible to identify a basic shape just from the distribution of its audible resonances.

  3. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture

    Directory of Open Access Journals (Sweden)

    S. Sumoharjo

    2013-06-01

    Full Text Available Integrated multi-trophic aquaculture pays more attention as a bio-integrated food production system that serves as a model of sustainable aquaculture, minimizes waste discharge, increases diversity and yields multiple products. The objectives of this research were to analyze the efficiency of total ammonia nitrogen biofiltration and its effect on carrying capacity of fish rearing units. Pilot-scale bioreactor was designed with eight run-raceways (two meters of each that assembled in series. Race 1-3 were used to stock silky worm (Tubifex sp as detrivorous converter, then race 4-8 were used to plant three species of leaf-vegetable as photoautotrophic converters, i.e; spinach (Ipomoea reptana, green mustard (Brassica juncea and basil (Ocimum basilicum. The three plants were placed in randomized block design based on water flow direction. Mass balance of nutrient analysis, was applied to figure out the efficiency of bio-filtration and its effect on carrying capacity of rearing units. The result of the experiment showed that 86.5 % of total ammonia nitrogen removal was achieved in 32 days of culturing period. This efficiency able to support the carrying capacity of the fish tank up to 25.95 kg/lpm with maximum density was 62.69 kg/m3 of fish biomass productionDoi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85 [How to cite this article: Sumoharjo, S.  and Maidie, A. (2013. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture.  International Journal of  Science and Engineering, 4(2,80-85. Doi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85

  4. Active control of interior noise within an irregular enclosure under the cooperation of point force and incident wave

    Institute of Scientific and Technical Information of China (English)

    GENG Houcai; RAO Zhushi; HAN Zushun; ZHANG Hualiang

    2002-01-01

    A new modeling method is developed for the active control of interior noise within an irregular three-dimensional cavity under the cooperation of point force and incident wave. The validity of this method is verified by a regular cuboid enclosure. With global and local per-formance functions, good results are obtained in the active control of noise within the irregular enclosure according to numerical investigations.

  5. Measure Guideline: Deep Energy Enclosure Retrofit for Interior Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Musunuru, S. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-04-01

    This Measure Guideline describes a deep energy enclosure retrofit (DEER) solution for insulating mass masonry buildings from the interior. It describes the retrofit assembly, technical details, and installation sequence for retrofitting masonry walls. Interior insulation of masonry retrofits has the potential to adversely affect the durability of the wall; this document includes a review of decision criteria pertinent to retrofitting masonry walls from the interior and the possible risk of freeze-thaw damage.

  6. Measure Guideline. Deep Energy Enclosure Retrofit for Interior Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Musunuru, S. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-04-30

    This Measure Guideline describes a deep energy enclosure retrofit solution for insulating mass masonry buildings from the interior. It describes the retrofit assembly, technical details, and installation sequence for retrofitting masonry walls. Interior insulation of masonry retrofits might adversely affect the durability of the wall. This guideline includes a review of decision criteria pertinent to retrofitting masonry walls from the interior and the possible risk of freeze-thaw damage.

  7. Possible astronomical references in the project of the megalithic enclosures of Gobekli Tepe

    CERN Document Server

    Magli, Giulio

    2013-01-01

    The megalithic enclosures of Gobekli Tepe (Urfa, Turkey) are the most ancient sacred structures of stone known so far, dating back to the 10 millennium BC. The possible presence of astronomical targets for these structures is analysed, and it turns out that they may have been oriented, or even originally constructed, to celebrate and successively follow the appearance of a new, extremely brilliant star in the southern skies: Sirius.

  8. Seed trait and rodent species determine seed dispersal and predation: evidences from semi-natural enclosures

    OpenAIRE

    Yi X; Wang Z.; Liu C; Liu G.

    2015-01-01

    Seed traits affect seed dispersal by animals. However, the combined role of seeds and dispersers in determining seed dispersal is not well explored. We attempted to test how seed traits and predators determine seed dispersal and predation interaction in a rodent-mediated seed dispersal system. Semi-natural enclosure experiments were conducted to investigate seed dispersal and predation of five sympatric tree species with different seed traits, Juglans mandshurica, Quercus mongolica, Pinus kor...

  9. Blooms of the dinoflagellate Glenodinium sanguineum obtained during enclosure experiments in Lake Tovel (N. Italy

    Directory of Open Access Journals (Sweden)

    Monica TOLOTTI

    2003-02-01

    Full Text Available Freshwater red tides due to dinoflagellates are less common than their marine analogues, which are usually a serious problem and can even be toxic. This was not the case for Lake Tovel in the Adamello-Brenta Natural Park (Southern Alps, Italy, where the dinoflagellate Glenodinium sanguineum Marchesoni accumulated carotenoids (astaxanthin-like compound and caused a spectacular and regular "summer reddening", which suddenly ceased in 1964. Today Lake Tovel is a temperate, meromictic (with dimictic mixolimnion, oligotrophic mountain lake, characterised by marked water level fluctuations. G. sanguineum is still present in the lake, although with markedly lower densities in comparison to the pre-1965 period. Enclosure studies were carried out to identify the main factors regulating the blooms. In 1998, by means of phosphorus enrichments, it was possible to obtain a marked increase in numbers of G. sanguineum. Phosphorus additions in similar enclosures in 1999, when weather conditions during the summer were not optimal (mostly cloudy with frequent rainfalls, did not have the same effect, since species known to thrive in spring or under icecover developed. In summer 2000, by attenuating light in one of the enclosures, it was shown that irradiance conditions strongly interacted with phosphorus availability in determining the species that dominated the phytoplankton. In summer 2001, G. sanguineum increased again in the enclosure enriched with phosphorus. Nitrogen was observed to become a limiting factor only in conditions forced by phosphorus additions. From the first four years of in situ experiments, we concluded that phosphorus and light conditions were among the key factors controlling the proliferation and the dominance of G. sanguineum.

  10. Construction and Validation of a Systematic Ethogram of Macaca fascicularis in a Free Enclosure

    OpenAIRE

    Fan Xu; Liang Xie; Xin Li; Qi Li; Tao Wang; Yongjia Ji; Fei Kong; Qunlin Zhan; Ke Cheng; Liang Fang; Peng Xie

    2012-01-01

    Behavioral studies in non-human primates have become ideal models for further investigations into advanced cognitive function in humans. To date, there is no systematic ethogram of the cynomolgus monkey (Macaca fascicularis) in a free enclosure. In a field observation of 6012 subjects, 107 distinct behaviors of M. fascicularis were preliminarily described. 83 of these behaviors were then independently validated through a randomized cohort and classified into 12 behavioral categories. 53 of th...

  11. Double-diffusive natural convection in an enclosure filled with nanofluid using ISPH method

    OpenAIRE

    Abdelraheem M Aly; Zehba A.S. Raizah

    2016-01-01

    The double-diffusive natural convection in an enclosure filled with nanofluid is studied using ISPH method. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. In addition the thermal energy equations include regular diffusion and cross-diffusion terms. In ISPH algorithm, a semi implicit velocity correction procedure is utilized and the pressure is implicitly evaluated by solving pressure Poisson equation. The results are presented with flow config...

  12. Measure Guideline: Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-05-01

    This Measure Guideline provides design and construction information for a deep energy enclosure retrofit (DEER) solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat, wood-framed roof with brick masonry exterior walls, using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat, wood-framed roofs with wood-framed exterior walls.

  13. Measure Guideline. Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-05-29

    This Measure Guideline provides design and construction information for a deep energy enclosure retrofit solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat wood-framed roof with brick masonry exterior walls using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat wood-framed roofs with wood-framed exterior walls.

  14. Thermosolutal bifurcation phenomena in porous enclosures subject to vertical temperature and concentration gradients

    Science.gov (United States)

    Mamou, M.; Vasseur, P.

    1999-09-01

    The Darcy model with the Boussinesq approximations is used to study double-diffusive instability in a horizontal rectangular porous enclosure subject to two sources of buoyancy. The two vertical walls of the cavity are impermeable and adiabatic while Dirichlet or Neumann boundary conditions on temperature and solute are imposed on the horizontal walls. The onset and development of convection are first investigated using the linear and nonlinear perturbation theories. Depending on the governing parameters of the problem, four different regimes are found to exist, namely the stable diffusive, the subcritical convective, the oscillatory and the augmenting direct regimes. The governing parameters are the thermal Rayleigh number, RT, buoyancy ratio, N, Lewis number, Le, normalized porosity of the porous medium, [epsilon], aspect ratio of the enclosure, A, and the thermal and solutal boundary condition type, [kappa], applied on the horizontal walls. On the basis of the nonlinear perturbation theory and the parallel flow approximation (for slender or shallow enclosures), analytical solutions are derived to predict the flow behaviour. A finite element numerical method is introduced to solve the full governing equations. The results indicate that steady convection can arise at Rayleigh numbers below the supercritical value, indicating the development of subcritical flows. At the vicinity of the threshold of supercritical convection the nonlinear perturbation theory and the parallel flow approximation results are found to agree well with the numerical solution. In the overstable regime, the existence of multiple solutions, for a given set of the governing parameters, is demonstrated. Also, numerical results indicate the possible occurrence of travelling waves in an infinite horizontal enclosure.

  15. Sexual development in fish, practical applications for aquaculture.

    Science.gov (United States)

    Cnaani, A; Levavi-Sivan, B

    2009-01-01

    Aquaculture is one of the fastest rising sectors of world food production. Hundreds of fish species are cultured, providing an affordable, high quality food source. Two aspects of sexual development are critically important for the continued improvement of cultured fish stocks: sexual dimorphism and control of reproduction. In this paper, we review the main methods used to control sex determination in fish and their application in some of the most widely cultured species. Specifically, we review the techniques available for the production of all-male, all-female, and sterile populations. Techniques for endocrinological control of reproduction are also discussed.

  16. Predicting salt advection in groundwater from saline aquaculture ponds

    Science.gov (United States)

    Verrall, D. P.; Read, W. W.; Narayan, K. A.

    2009-01-01

    SummaryThis paper predicts saltwater advection in groundwater from leaky aquaculture ponds. A closed form solution for the potential function, stream function and velocity field is derived via the series solutions method. Numerically integrating along different streamlines gives the location (or advection front) of saltwater throughout the domain for any predefined upper time limit. Extending this process produces a function which predicts advection front location against time. The models considered in this paper are easily modified given knowledge of the required physical parameters.

  17. Food intake rate and delivery strategy in aquaculture

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In aquaculture, it is important to estimate in advance how much food cultured animals would take. The rate of food consumption by cultured animals to available food amount is defined as the food intake rate (FIR) in this paper. To some extents, FIR reflects the quality of food, the health of cultured animals and the delivery efficiency. In practice, it is difficult to estimate in advance the accurate quantity of food that cultured animal needs. Usually, food is provided more than the need by animals, causing excess food that may pollute water and environment. Our experiments in past years show that FIR at 80% is recommended.

  18. Future challanges for the maturing Norwegian salmon aquaculture industry

    DEFF Research Database (Denmark)

    Asche, Frank; Guttormsen, Atle G.; Nielsen, Rasmus

    2013-01-01

    In this paper, we analyze total factor productivity change in the Norwegian salmon aquaculture sector from 1996 to 2008. During this period, the production has on average been growing with 8% per year. At the same time, the price of salmon has stabilized indicating that an increase in demand...... is driving the production growth rather than increasing productivity in the sector. A Malmquist index approach is used to calculate total factor productivity change applying data envelopment analysis to construct the underlying production frontier. Furthermore, the bootstrap approach has been applied...

  19. Effect of Rotation on Natural Convection in Differentially Heated Rotating Enclosure by Numerical Simulation

    Directory of Open Access Journals (Sweden)

    M. Narendra Kumar

    2016-01-01

    Full Text Available Natural convection heat transfer in a two dimensional unsteady rotating differentially heated enclosure is studied numerically in this paper. The enclosure is filled with air and executes a steady counterclockwise rotation about the centre of the enclosure. A finite volume code on a staggered grid arrangement with TDMA algorithm is developed and employed to solve the governing equations subject to Boussinesq approximation. The numerical investigation is carried out for fixed Prandtl number equal to 0.71, Rayleigh number equal to1.1×〖10〗^5 while Taylors number vary from5.2×〖10〗^4 to 3.3×〖10〗^5and Rotational Rayleigh number from 4.9×〖10〗^2 to 3.1×〖10〗^3.Results reveal that there are considerable change in heat transfer rates beyond 15 rpm. The effect of rotation on the Nusselt number for a given Rayleigh number is shown in the present work which is not normally indicated and discussed in the available literature

  20. Initial computational fluid dynamics modeling of the Giant Magellan Telescope site and enclosure

    Science.gov (United States)

    Danks, Ryan; Smeaton, William; Bigelow, Bruce; Burgett, William

    2016-08-01

    In the era of extremely large telescopes (ELTs), with telescope apertures growing in size and tighter image quality requirements, maintaining a controlled observation environment is critical. Image quality is directly influenced by thermal gradients, the level of turbulence in the incoming air flow and the wind forces acting on the telescope. Thus any ELT enclosure must be able to modulate the speed and direction of the incoming air and limit the inflow of disturbed ground-layer air. However, gaining an a priori understanding of the wind environment's impacts on a proposed telescope is complicated by the fact that telescopes are usually located in remote, mountainous areas, which often do not have high quality historic records of the wind conditions, and can be subjected to highly complex flow patterns that may not be well represented by the traditional analytic approaches used in typical building design. As part of the design process for the Giant Magellan Telescope at Cerro Las Campanas, Chile; the authors conducted a parametric design study using computational fluid dynamics which assessed how the telescope's position on the mesa, its ventilation configuration and the design of the enclosure and windscreens could be optimized to minimize the infiltration of ground-layer air. These simulations yielded an understanding of how the enclosure and the natural wind flows at the site could best work together to provide a consistent, well controlled observation environment. Future work will seek to quantify the aerothermal environment in terms of image quality.

  1. Active Noise Control in a Three Dimensional Enclosure Using Multichannel Fuzzy LMS Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Do [Dankook University (Korea, Republic of); Kim, Kyun Tae [Haitai Electronics R and D Cemter (Korea, Republic of)

    1998-05-01

    In this paper, active noise control(ANC) in an enclosure using multi-channel fuzzy LMS(MCFLMS) algorithm is considered. A new model for a secondary path transfer function, which has common acoustical poles that correspond to resonance properties of an enclosure, is used. Since this model requires far fewer variable parameters to represent secondary path transfer functions than those of conventional all-zero or pole and zero models, it reduces the computational complexity for an active noise control system. A MCFLMS algorithm, where the convergence coefficients of a multi-channel LMS(MCLMS) algorithm is derived by a fuzzy inference engine, is proposed. This algorithm shows better convergence than the existing MCLMS algorithms and it does not require pre-adjustment of convergence parameters, so it could be easily applied to practical ANC systems. Computer simulations and experiments were performed to show the effectiveness of the proposed algorithm in experimental enclosure. The proposed method shows better results in both computer simulations and experiments. (author). 14 refs., 10 figs., 2 tabs.

  2. Acoustic Pressure Waves in Vibrating 3-D Laminated Beam-Plate Enclosures

    Directory of Open Access Journals (Sweden)

    Charles A. Osheku

    2009-01-01

    Full Text Available The effect of structural vibration on the propagation of acoustic pressure waves through a cantilevered 3-D laminated beam-plate enclosure is investigated analytically. For this problem, a set of well-posed partial differential equations governing the vibroacoustic wave interaction phenomenon are formulated and matched for the various vibrating boundary surfaces. By employing integral transforms, a closed form analytical expression is computed suitable for vibroacoustic modeling, design analysis, and general aerospace defensive applications. The closed-form expression takes the form of a kernel of polynomials for acoustic pressure waves showing the influence of linear interface pressure variation across the axes of vibrating boundary surfaces. Simulated results demonstrate how the mode shapes and the associated natural frequencies can be easily computed. It is shown in this paper that acoustic pressure waves propagation are dynamically stable through laminated enclosures with progressive decrement in interfacial pressure distribution under the influence of high excitation frequencies irrespective of whether the induced flow is subsonic, sonic , supersonic, or hypersonic. Hence, in practice, dynamic stability of hypersonic aircrafts or jet airplanes can be further enhanced by replacing their noise transmission systems with laminated enclosures.

  3. Mixed convection flow of nanofluid in a square enclosure with an intruded rectangular fin

    Science.gov (United States)

    Cong, Ran; Zhou, Xuanyu; De Souza Machado, Bruno; Das, Prodip K.

    2016-07-01

    Mixed convection flow in enclosures has been a subject of interest for many years due to their ever increasing applications in solar collectors, electronic cooling, lubrication technologies, food processing, and nuclear reactors. In comparison, little effort has been given to the problem of mixed convection in enclosures filled with nanofluids, while the addition of nanoparticles in a fluid base to alter specific material properties is considered a feasible solution for many heat transfer problems. Mixed convection of nanofluids is a challenging problem as the addition of nanoparticles changes the fluid's thermo-physical properties as well as due to the complex interactions among inertia, viscous, and buoyancy forces. In this study, a two-dimensional steady-state numerical model has been developed to investigate mixed convection flow of nanofluids in a square enclosure with an intruded rectangular fin and to optimize the fin geometry for maximizing the heat transfer using the Constructal design. The model has been developed using ANSYS-FLUENT for various fin geometries. Flow fields, temperature fields, and heat transfer rates are examined for different values of Rayleigh and Reynolds numbers for several geometries of the fin with the aim of maximizing the heat transfer from the fin to the surrounding flow. Outcome of this study provides important insight into the heat transfer behavior of nanofluids, which will help in developing novel geometries with enhanced and controlled heat transfer for solar collectors and electronic devices.

  4. Non—Darcian and Anisotropic Effects on Natural Convection in Horizontal Porous Media Enclosure

    Institute of Scientific and Technical Information of China (English)

    ZhangJingzhou; SunRenqia

    1996-01-01

    Natural convection heat transfer in a horizontal enclosure filled with anisotropic porous media,being isothermally heated at bettom and cooled at top while the vertical walls being adiabatic,is numerically studied by applying the Brinkman model-a modified form of Darcy model giving consideratioin to the viscous effect.The results show that:(1)a larger permeability ratio(K*) causes a lower flow intensity in the enclosure and a smaller Nusselt number,all Nusselt numbers approach unity in the limit of K*→∞;a larger thermal conductivity ratio(λ*) causes a stranger distortion of isotherms in the enclosure and a higher flow velocity near the walls,all the Nusselt numbers approach unity in the limit of λ*-→0,the permeability and thermal conductivity ratios generally have opposing effects on the Nusselt number.(2) an increasing Darcy number decreases the flow intensity and heat tansfer rates,which is more significant at a lower permeability ratio.In particular,with K*≤0.25,the Nusselt number for Da=10-3 would differ from that of Darcy flow up to an amount of 30%,an analysis neglecting the non-Darican effect will inevitably be of considerable error.

  5. Extraction of enclosure culture area from SPOT-5 image based on texture feature

    Science.gov (United States)

    Tang, Wei; Zhao, Shuhe; Ma, Ronghua; Wang, Chunhong; Zhang, Shouxuan; Li, Xinliang

    2007-06-01

    The east Taihu lake region is characterized by high-density and large areas of enclosure culture area which tend to cause eutrophication of the lake and worsen the quality of its water. This paper takes an area (380×380) of the east Taihu Lake from image as an example and discusses the extraction method of combing texture feature of high resolution image with spectrum information. Firstly, we choose the best combination bands of 1, 3, 4 according to the principles of the maximal entropy combination and OIF index. After applying algorithm of different bands and principal component analysis (PCA) transformation, we realize dimensional reduction and data compression. Subsequently, textures of the first principal component image are analyzed using Gray Level Co-occurrence Matrices (GLCM) getting statistic Eigen values of contrast, entropy and mean. The mean Eigen value is fixed as an optimal index and a appropriate conditional thresholds of extraction are determined. Finally, decision trees are established realizing the extraction of enclosure culture area. Combining the spectrum information with the spatial texture feature, we obtain a satisfied extracted result and provide a technical reference for a wide-spread survey of the enclosure culture area.

  6. Adoption of Aquaculture Technology by Fish Farmers in Imo State of Nigeria

    Science.gov (United States)

    Ike, Nwachukwu; Roseline, Onuegbu

    2007-01-01

    This paper evaluated the level of adoption of aquaculture technology extended to farmers in Imo State, Nigeria. To improve aquaculture practice in Nigeria, a technology package was developed and disseminated to farmers in the state. This package included ten practices that the farmers were supposed to adopt. Eighty-two respondents were randomly…

  7. Draft genome sequences of four virulent aeromonas hydrophila strains from catfish aquaculture

    Science.gov (United States)

    Since 2009, a clonal group of virulent Aeromonas hydrophila (VAh) strains has been causing severe disease in the catfish aquaculture industry in the Southeastern United States. Here, we report draft genomes of four A. hydrophila isolates from catfish aquaculture that represent this clonal group....

  8. 78 FR 5403 - Fisheries of the Caribbean, Gulf, and South Atlantic; Aquaculture

    Science.gov (United States)

    2013-01-25

    ..., Gulf, and South Atlantic; Aquaculture AGENCY: National Marine Fisheries Service (NMFS), National... the Fishery Management Plan for Regulating Offshore Marine Aquaculture in the ] Gulf of Mexico (FMP; formerly the Draft Generic Amendment to Gulf of Mexico Fishery Management Plans for Offshore...

  9. Peracetic acid is an optimal disinfectant for fish-microalgae integrated multi-trophic aquaculture systems

    Science.gov (United States)

    Integrated multi-trophic aquaculture is a promising direction for the sustainable development of aquaculture. Instead of releasing nutrition-rich waste to the environment or decomposition of nutrients via the biofilter, the ‘waste’ from fish can be recycled to produce byproducts (e.g., algae, plants...

  10. Life cycle assessment of food production in integrated agriculture–aquaculture systems of the Mekong Delta

    NARCIS (Netherlands)

    Phong, L.T.; Boer, de I.J.M.; Udo, H.M.J.

    2011-01-01

    This study evaluated the environmental impact of integrated agriculture–aquaculture (IAA) farming systems in the Mekong Delta that differ in types of aquaculture intensification. Daily inputs and outputs for rice, fruits, vegetables, pigs, poultry, and fish were collected on 11 farms over a period o

  11. Tracing dissolved organic matter (DOM) from land-based aquaculture systems in North Patagonian streams

    DEFF Research Database (Denmark)

    Nimptsch, Jorge; Woelfl, Stefan; Osorio, Sebastian

    2015-01-01

    Chile is the second largest producer of salmonids worldwide. The first step in the production of salmonids takes place in land-based aquacultures. However, the effects of the discharge from these aquacultures on stream dissolved organic matter (DOM) content, molecular composition and degradabilit...

  12. Application and analytical verification of peracetic acid use in different types of freshwater aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    2011-01-01

    by the aquaculture industry as it is difficult to apply in correct dosages. This study describes the degradation kinetics of PAA when used as an aquaculture disinfectant. Effects of temperature, organic matter content and initial PAA dosage on the chemical fate of PAA is reported. Furthermore, investigations...

  13. Why are prices in wild catch and aquaculture industries so different?

    Science.gov (United States)

    Villasante, Sebastián; Rodríguez-González, David; Antelo, Manel; Rivero-Rodríguez, Susana; Lebrancón-Nieto, Joseba

    2013-12-01

    Through a comparative analysis of prices in capture fisheries and aquaculture sectors, the objectives of this paper are a) to investigate three the trends in prices of forage catches to feed the aquaculture species, b) to analyze the amount of fish species need to feed aquaculture species in order to assess the level of efficiency in resource use, and c) to examine the degree of economic concentration either in wild-catch industry and aquaculture sectors. The results show that prices of cultivated species are higher than prices of the same species when harvested from the sea. We explain this fact by the interplay of three forces. First, the amount of wild fish to feed aquaculture species continues to improve over time. Second, the pressure of fishing activities has not been reduced since catches of most forage fishes are declining, which induce higher prices of capture species that feed aquaculture production. Third, the level of seafood market concentration is significantly higher in aquaculture than in wild catches, which generates higher prices in aquaculture.

  14. ‘Halophyte filters’: the potential of constructed wetlands for application in saline aquaculture

    NARCIS (Netherlands)

    Lange, de H.J.; Paulissen, M.P.C.P.; Slim, P.A.

    2013-01-01

    World consumption of seafood continues to rise, but the seas and oceans are already overexploited. Land-based (saline) aquaculture may offer a sustainable way to meet the growing demand for fish and shellfish. A major problem of aquaculture is nutrient waste, as most of the nutrients added through f

  15. Aquaculture, Fresh Water, DATCP licensed aquaculture producers, Published in 2009, 1:24000 (1in=2000ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aquaculture, Fresh Water dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as...

  16. A comprehensive survey on selective breeding programs and seed market in the European aquaculture fish industry

    DEFF Research Database (Denmark)

    Chavanne, Hervé; Janssen, Kasper; Hofherr, Johann;

    2016-01-01

    reared fish species were targeted. A total of 31 respondents contributed to the survey, representing 75 % of European breeding organizations. Family-based breeding schemes were predominant, but individual selection was more frequently applied in marine species. Artificial fertilization is the preferred...... of molecular tools is now common in all programs, mainly for pedigree traceability. An increasing number of programs use either genomic or marker-assisted selection. Results related to the seed production market confirmed that for Atlantic salmon there are a few dominant players at the European level, with 30......–50 % market share. Only part of the European fish aquaculture industry today fully exploits selective breeding to the best advantage. A larger impact assessment still needs to be made by the remainder, particularly on the market share of fish seed (eggs, larvae or juveniles) and its consequences for hatchery...

  17. Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Yao; Liu, Baoliang; Lei, Jilin; Guan, Changtao; Huang, Bin

    2016-07-01

    A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-ɛ turbulence model was applied to describe the flow, the discrete phase model (DPM) was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that: (1) the realizable k-ɛ model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; (2) the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; (3) a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of ≤ 5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering.

  18. Authentication of fishery and aquaculture products by multi-element and stable isotope analysis.

    Science.gov (United States)

    Li, Li; Boyd, Claude E; Sun, Zhenlong

    2016-03-01

    The market of fishery and aquaculture products is globalized with increasing numbers of mislabeled products. This highlights the need for approaches to indentify the origin of these products. Among the measures used to identify the origin of other agro-products, multi-element and stable isotope analysis are promising approaches to identify the authenticity and traceability of fishery and aquaculture products. The present paper reviews the use of multi-element and stable isotope analysis to determine the origin of fishery and aquaculture products. Principles and limitations of each method will be illustrated and perspectives for traceability of fishery and aquaculture products will be discussed. The aim of this review is to mediate fundamental knowledge for the interpretation of experimental data on authentication of aquaculture products.

  19. Effect of Wind-solar Complementary Increasing Oxygen System in Aquaculture

    Directory of Open Access Journals (Sweden)

    Guodong You

    2013-12-01

    Full Text Available In order to explore a sustainable aquaculture methodology, water was increased oxygen by a wind-solar power which was tested in a production period of the Penaeus vannamei in paper. The result shows that, compareing with the conventional aerating comparison, the system could improve water environment in ponds and dissolved oxygen, temperature, pH value and the content of nitrite stably and uniformly change; make full use of wind energy and solar energy clean energy, save 100% on power consumption, 15.9% on bait, 46.0% on drug; save aquaculture costs, increase income 282%. Using "Wind-solar" complementary increasing oxygen can improve water environment, save power, reduce aquaculture costs, increase aquaculture production and income, provide a new thought and method for green and ecological aquaculture, so it has high value of practical application.

  20. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    Recent discharge restrictions on antibiotics and chemotherapeutant residuals used in aquaculture have several implications to the aquaculture industry. Better management practices have to be adopted, and documentation and further knowledge of the chemical fate is required for proper administration...... and to support the ongoing development of a sustainable aquaculture industry. A focal point of this thesis concerns formaldehyde (FA), a commonly used chemical additive with versatile aquaculture applications. FA is safe for use with fish and has a high treatment efficiency against fungal and parasite infections...... of these agents on biofilter nitrification performance. All experiments were conducted through addition of chemical additives to closed pilot scale recirculating aquaculture systems (RAS) with fixed media submerged biofilters under controlled operating conditions with rainbow trout (Oncorhynchus mykiss...

  1. Characterization of integrons and tetracycline resistance determinants in Aeromonas spp. isolated from South African aquaculture systems.

    Science.gov (United States)

    Jacobs, Liezl; Chenia, Hafizah Y

    2007-03-20

    An increasing incidence of multidrug resistance amongst Aeromonas spp. isolates, which are both fish pathogens and emerging opportunistic human pathogens, has been observed worldwide. This can be attributed to the horizontal transfer of mobile genetic elements, viz.: plasmids and class 1 integrons. The antimicrobial susceptibilities of 37 Aeromonas spp. isolates, from tilapia, trout and koi aquaculture systems, were determined by disc-diffusion testing. The plasmid content of each isolate was examined using the alkaline lysis protocol. Tet determinant type was determined by amplification using two degenerate primer sets and subsequent HaeIII restriction. The presence of integrons was determined by PCR amplification of three integrase genes, as well as gene cassettes, and the qacEDelta1-sulI region. Thirty-seven Aeromonas spp. isolates were differentiated into six species by aroA PCR-RFLP, i.e., A. veronii biovar sobria, A. hydrophila, A. encheleia, A. ichtiosoma, A. salmonicida, and A. media. High levels of resistance to tetracycline (78.3%), amoxicillin (89.2%), and augmentin (86.5%) were observed. Decreased susceptibility to erythromycin was observed for 67.6% of isolates. Although 45.9% of isolates displayed nalidixic acid resistance, majority of isolates were susceptible to the fluoroquinolones. The MAR index ranged from 0.12 to 0.59, with majority of isolates indicating high-risk contamination originating from humans or animals where antibiotics are often used. Plasmids were detected in 21 isolates, with 14 of the isolates displaying multiple plasmid profiles. Single and multiple class A family Tet determinants were observed in 27% and 48.7% of isolates, respectively, with Tet A being the most prevalent Tet determinant type. Class 1 integron and related structures were amplified and carried different combinations of the antibiotic resistance gene cassettes ant(3'')Ia, aac(6')Ia, dhfr1, oxa2a and/or pse1. Class 2 integrons were also amplified, but the

  2. 40 CFR 122.25 - Aquaculture projects (applicable to State NPDES programs, see § 123.25).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Aquaculture projects (applicable to... DISCHARGE ELIMINATION SYSTEM Permit Application and Special NPDES Program Requirements § 122.25 Aquaculture... aquaculture projects, as defined in this section, are subject to the NPDES permit program through section...

  3. Transient Sound Intensity Measurements for Evaluating the Spatial Information of Sound Fields in Reverberant Enclosures.

    Science.gov (United States)

    Abdov, Adel Abdel-Moneim

    Over the last twenty years, new subjectively relevant objective room-acoustic indicators for evaluating the acoustical quality of an enclosure have been introduced. While these indicators give new insight into the acoustical "Goodness" of a listener position, in order to design halls, assess or to correct an acoustical defect in an existing enclosure, there is a need to understand to what extent they are influenced by the physical design features of the enclosure. To meet such a need, information about the directional characteristics of sound is required. The spatial distribution of sound energy is usually not considered due to lack of an efficient, accurate and easy to perform measurement method. The main objectives of the present study are, first; to review known and speculative room-acoustic indicators for use in assessing reverberant spaces such as concert halls, opera houses, multi-purpose halls and churches. Second, to introduce an easy to perform measurement method for directional sensing in sound fields. Third, to develop a simple and inexpensive PC-based instrument primarily for the measurement of sound fields directional characteristics as well as contemporary room-acoustic indicators. Fourth, to propose new room-acoustic indicators which have relevance to directional information. This study introduces a three-dimensional sound intensity measurement technique for obtaining spatial information of sound fields in an enclosure. The technique has been validated and its accuracy investigated. The method gives results that provide valuable information regarding the directional behaviour of sound in enclosures. Subsequently both the system and the measurement method were applied to known spaces as example applications in order to assess sound quality, to detect the effect of the surrounding interior features of the space, and to assess potential diagnostic capability with respect to interior physical changes. The study has validated the measurement procedure as

  4. Numerical modeling of mixing in large stably stratified enclosures using TRACMIX++

    Science.gov (United States)

    Christensen, Jakob

    This PhD dissertation focuses on the numerical modeling of stably stratified large enclosures. In stably stratified volumes, the distribution of temperature, species concentration etc become essentially 1-D throughout most of the enclosure. When the fluid in an enclosure is stratified, wall boundary buoyant jets, forced buoyant jets (injection of fluid) and natural convection plumes become the primary sources of mixing. The time constants for the buoyant jets may be considered as much smaller than the time constant for the mixing of the stratified ambient fluid, provided the combined volume occupied by the buoyant jets is small compared to the volume of the enclosure. Therefore, fluid transport by the buoyant jets may be considered as occurring instantaneously. For this reason this work focuses on deriving a numerical method which is able to solve the 1-D vertical fluid conservation equations, as given in Peterson (1994). Starting with the Eulerian fluid conservation equations given in Peterson (1994), a set of Lagrangian fluid conservation equations were derived. Combining the Lagrangian approach with operator splitting such that the convective step and the diffusive step is separated renders a very efficient, accurate, and stable numerical method as it is shown in this text. Since the stratified flow field frequently exhibits very strong gradients or so-called fronts, the generation of these fronts has to be accurately detected and tracked by the numerical method. Flow in stably stratified large enclosure has typically been modeled in the past using 1- or 2-zone models. The present model is new in that it belongs to the K-zone models where the number of zones is arbitrarily large and depends on the complexity of the solution and the accuracy requirement set by the user. Because fronts are present in the flow field, a Lagrangian type numerical method is used. A Lagrangian method facilitates front tracking and prevents numerical diffusion from altering the shape of

  5. Coastal pollution due to increasing nutrient flux in aquaculture sites

    Science.gov (United States)

    David, C. P. C.; Sta. Maria, Y. Y.; Siringan, F. P.; Reotita, J. M.; Zamora, P. B.; Villanoy, C. L.; Sombrito, E. Z.; Azanza, R. V.

    2009-07-01

    The supply of nitrogen and phosphorus in coastal zones through time is reflected in the nutrients’ concentration in the sediment record. Five aquaculture sites in the Philippines were investigated in an effort to establish how long-term changes in land and coastal water use could have led to biogeochemical modifications affecting the coastal ecosystem. Samples from study sites show a narrow concentration range for nitrogen and did not reveal any significant trend through time. In contrast, phosphorus concentrations in most sites start at less than 20 ppm in sediments 30 years and older. The phosphorus value continuously increase in younger sediments, with each site having a different magnitude change as well as timing of when the major increase happened. The uppermost 10 cm, representing the last 15 years in sites with age control, typically show a 2- to 3-fold increase in P load values. Historical increase in nutrient load also coincides with harmful algal bloom events in each area; when effective P input exceeded 130 kg/km2 per year. Lastly, the observed increase may be attributed to several factors including physical attributes of the area, urbanization of coastal zones, but most importantly in the proliferation of aquaculture activities.

  6. Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

    Science.gov (United States)

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

    While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lemaneiformis significantly more than either G. conferta or G. cornea. The crab, however, consumed equivalent amounts of G. lemaneiformis and G. conferta, but did not consume G. cornea. Organic content of these algae, an important feeding cue for some mesograzers, could not account for these differences. We further assessed the susceptibility of a candidate species for aquaculture, G. lemaneiformis, against local algae, including common epiphytes. When given a choice of four algae, amphipods preferred the green alga Ulva lactuca over Jania rubens. However, consumption of U. lactuca was equivalent to those of G. lemaneiformis and Padina pavonica. In contrast, the crab showed a marked and significant preference for G. lemaneiformis above any of the other three algae offered. Our results suggest that G. cornea is more resistant to herbivory from common mesograzers and that, contrary to expectations, mixed cultures or epiphyte growth on G. lemaneiformis cannot reduce damage to this commercially appealing alga if small herbivores are capable of recruiting into culture ponds. Mixed cultures may be beneficial when culturing other Gracilaria species. PMID:22711945

  7. NALYSIS OF ROMANIAN FISHERIES AND AQUACULTURE IN REGIONAL CONTEXT

    Directory of Open Access Journals (Sweden)

    Mihaela\tNECULITA

    2015-06-01

    Full Text Available Integration in European Union assumes obtaining certain benefits. Fisheries and aquaculture can provide a key contribution to food security and poverty alleviation. Employment in the sector has grown faster than the world’s population, providing jobs and supports the livelihoods of hundreds of millions. Fish continues to be one of the most- traded food commodities worldwide being very important for developing countries. However, productivity gains in fisheries do not always imply long-term increases in supply. Developing countries are continuing their efforts to clarify the linkage between development activities and sustainable resource use. Both population and economic growth are putting enormous additional pressures on inland and marine fisheries resources as contributors to food security and providers of a social safety net. At the same time, the use of domestic fisheries to generate foreign exchange is exacerbating allocation issues between artisan and industrial fleets. The actual fisheries legislation was influence by social, economic and environmental considerations. The paper proposes an integrated analysis of Romanian situation by means of data and statistics provided by European and national statistics institutions. Fisheries in general and aquaculture sector in particular could be regarded as an advantage for Romania in the European competition. The main problem of the Romanian fisheries is its unsatisfactory competitiveness both regarding the domestic and European market.

  8. From eco-sustainability to risk assessment of aquaculture products.

    Science.gov (United States)

    Gandini, G; Ababouch, L; Anichini, L

    2009-09-01

    The increasing demand for fishery products and the technical and commercial opportunities now available make the development of aquaculture an important subject for the policy of the fishery sector, in particular concerning aspects of its environmental and ecological sustainability. The latest studies show that it is possible to apply an ecological approach to the aquaculture sector and hence increase the interactions between fisheries and other activities such as fish/molluscs, fish/seaweed, rice-growing/fish. In this way we take part in the improvement of the environment thanks to the recycling of organic food, the reduction of pesticide use and the control of environmental euthrophication. In order to support and facilitate trade, but at the same time ensure the safety and quality of products, a harmonization of the policies for food safety protecting the products throughout the whole food chain is required (from the sea to the table). The above mentioned policy, based on scientific knowledge, relies on the analysis of risks from the competent Authorities and on the proper application of HACCP from the industries of the sector.

  9. Detecting and monitoring aquacultural patterns through multitemporal SAR imagery analysis

    Science.gov (United States)

    Profeti, Giuliana; Travaglia, Carlo; Carla, Roberto

    2003-03-01

    The inventory and monitoring of aquaculture areas are essential tools for decision-making at a governmental level in developing countries. With the use of satellite imagery, these tasks can be performed in an accurate, rapid and objective way. This approach is also economically viable, as the worth of aquaculture far outweighs its cost. This paper describes a methodology for identifying and monitoring shrimp farms by means of multi-temporal satellite SAR data. SAR offer all-weather capabilities, an important characteristic since shrimp farms exist in tropical and sub-tropical areas. Moreover, the backscatter effect created by the dykes surrounding the ponds produces a typical pattern which allows the interpreter to distinguish them from other types of water-covered surfaces. However, the presence of speckle noise limits the interpretability of SAR imagery. To increase it, a multi-temporal set of four scenes covering the study area was processed by using a method that enhances time-invariant spatial features and reduces speckle without compromising the geometrical resolution of the images. The enhanced SAR imagery has proved to be valuable in identifying shrimp farm patterns with a field-tested accuracy of more than 90 percent. The methodology reported in this study has been tested with the ground truth obtained under operative conditions in Sri Lanka, thanks to the support of the FAO TCP/SRL/6712 project.

  10. PROBLEMS OF BIOFOULING ON FISH–CAGE NETS IN AQUACULTURE

    Directory of Open Access Journals (Sweden)

    Merica Slišković

    2002-09-01

    Full Text Available Biofouling on fish–cage netting is a serious technical and economical problem to aquaculture worldwide. Compensation for the effects of biofouling must be included in cage system design and planning, as fouling can dramatically increase both weight and drag. Settlements of sessile plants and animals, with accumulation of the detritus diminish the size of mesh and can rapidly occlude mesh. Negative effect of smaller mesh size is changing in water flow trough the cages. Biofouling problems necessitating purchase of a second sets of nets or more, and frequent cleaning and changing of biofouling. Changing and cleaning frequency depend on many factors such as: location of cages (near the coast or off shore, productivity of that location, time of the year, time period in which the cages are placed on that location (cause of loading of phosphorus and nitrogen from the unconsumed food in the sediment. Net changing and cleaning procedures are labor and capital intensive. Process of the cleaning of the nets is inadequate, especially when there isnžt adequate equipment available as it is case in smaller aquaculture industry. Chemical control of biofouling e. g. use of antifoulants is questioningly cause of their possible negative effects on breeding species and environment.

  11. Application of Aquaculture Monitoring System Based on CC2530

    Science.gov (United States)

    Chen, H. L.; Liu, X. Q.

    In order to improve the intelligent level of aquaculture technology, this paper puts forward a remote wireless monitoring system based on ZigBee technology, GPRS technology and Android mobile phone platform. The system is composed of wireless sensor network (WSN), GPRS module, PC server, and Android client. The WSN was set up by CC2530 chips based on ZigBee protocol, to realize the collection of water quality parameters such as the water level, temperature, PH and dissolved oxygen. The GPRS module realizes remote communication between WSN and PC server. Android client communicates with server to monitor the level of water quality. The PID (proportion, integration, differentiation) control is adopted in the control part, the control commands from the android mobile phone is sent to the server, the server again send it to the lower machine to control the water level regulating valve and increasing oxygen pump. After practical testing to the system in Liyang, Jiangsu province, China, temperature measurement accuracy reaches 0.5°C, PH measurement accuracy reaches 0.3, water level control precision can be controlled within ± 3cm, dissolved oxygen control precision can be controlled within ±0.3 mg/L, all the indexes can meet the requirements, this system is very suitable for aquaculture.

  12. Potential of palm oil utilisation in aquaculture feeds.

    Science.gov (United States)

    Ng, Wing-Keong

    2002-01-01

    One key ingredient used in the formulation of aquafeed is fish oil, which is produced from small marine pelagic fish and represents a finite fishery resource. At the present time, global fish oil production has reached a plateau and is not expected to increase beyond current levels. Recent estimates suggest that fish oils may be unable to meet demands from the rapidly growing aquaculture industry by as early as 2005. Therefore, there is currently great interest within the aquafeed industry in evaluating alternatives to fish oils. The ever-expanding oil palm cultivation in Malaysia and other tropical countries offers the possibility of an increased and constant availability of palm oil products for aquafeed formulation. Research into the use of palm oil in aquafeed begun around the mid-1990s and this review examines some of the findings from these studies. The use of palm oil in fish diets has generally shown encouraging results. Improved growth, feed efficiency, protein utilisation, reproductive performance and higher concentrations of alpha-tocopherol in fish fillets have been reported. Recent evidence for the ability of palm oil to substitute for fish oil in catfish diets is reviewed. The potential of palm oil use in aquafeed and future experimental directions are suggested. The aquaculture feed industry offers a great avenue to increase and diversify the use of palm oil-based products.

  13. Antibiotics, Antibiotic Resistance Genes, and Bacterial Community Composition in Fresh Water Aquaculture Environment in China.

    Science.gov (United States)

    Xiong, Wenguang; Sun, Yongxue; Zhang, Tong; Ding, Xueyao; Li, Yafei; Wang, Mianzhi; Zeng, Zhenling

    2015-08-01

    Environmental antibiotic resistance has drawn increasing attention due to its great threat to human health. In this study, we investigated concentrations of antibiotics (tetracyclines, sulfonamides and (fluoro)quinolones) and abundances of antibiotic resistance genes (ARGs), including tetracycline resistance genes, sulfonamide resistance genes, and plasmid-mediated quinolone resistance genes, and analyzed bacterial community composition in aquaculture environment in Guangdong, China. The concentrations of sulfametoxydiazine, sulfamethazine, sulfamethoxazole, oxytetracycline, chlorotetracycline, doxycycline, ciprofloxacin, norfloxacin, and enrofloxacin were as high as 446 μg kg(-1) and 98.6 ng L(-1) in sediment and water samples, respectively. The relative abundances (ARG copies/16S ribosomal RNA (rRNA) gene copies) of ARGs (sul1, sul2, sul3, tetM, tetO, tetW, tetS, tetQ, tetX, tetB/P, qepA, oqxA, oqxB, aac(6')-Ib, and qnrS) were as high as 2.8 × 10(-2). The dominant phyla were Proteobacteria, Bacteroidetes, and Firmicutes in sediment samples and Proteobacteria, Actinobacteria and Bacteroidetes in water samples. The genera associated with pathogens were also observed, such as Acinetobacter, Arcobacter, and Clostridium. This study comprehensively investigated antibiotics, ARGs, and bacterial community composition in aquaculture environment in China. The results indicated that fish ponds are reservoirs of ARGs and the presence of potential resistant and pathogen-associated taxonomic groups in fish ponds might imply the potential risk to human health.

  14. Nutritional analysis of freshwater and marine amphipods from the Strait of Gibraltar and potential aquaculture applications

    Science.gov (United States)

    Baeza-Rojano, Elena; Hachero-Cruzado, Ismael; Guerra-García, José M.

    2014-01-01

    Four gammarid and four caprellid amphipod species from the Strait of Gibraltar were analyzed to study their nutritional contents: Caprella dilatata, Caprella equilibra, Caprella grandimana, Caprella penantis, Elasmopus rapax, Hyale perieri and Jassa sp. from marine water habitats and Echinogammarus sp. from freshwater habitats. Lipids, proteins, carbohydrates, ash and water contents were measured. Proteins and ash were the most abundant components in all the species, ranging between 37.9 and 44.6% and 29.3 and 39.7% dry weight, respectively. The lipid and carbohydrate contents showed lower levels (5.1-9.6% and 3.1-9.1% dry weight, respectively). No significant differences in general biochemical composition were found between gammarid and caprellid species. The most abundant fatty acids were the polyunsaturated ones (38.3%) with high levels of EPA (20:5(n-3)) with 8.5 to 17.7%, DHA (22:6(n-3)) with 0.9 to 13.6% and ARA (20:4(n-6)) with 1.7 to 5.8%. Caprellid species were characterized by a higher percentage of polyunsaturated fatty acids, while the freshwater gammarid species showed the lowest levels. According to lipid classes, caprellids had higher phospholipids levels and lower triacylglycerol levels, as well as a higher content of polar lipids than the gammarids, being more suitable for their use in aquaculture. Differences in the general biochemical composition between species can be related to habitat characteristics, diets and environmental conditions. Advantages and disadvantages of the use of these organisms in aquaculture are discussed.

  15. Prescription of antimicrobial drugs in Norwegian aquaculture with an emphasis on "new" fish species.

    Science.gov (United States)

    Grave, Kari; Hansen, Magne Kjerulf; Kruse, Hilde; Bangen, Marit; Kristoffersen, Anja Bråthen

    2008-02-01

    The usage of antimicrobial (AM) drugs in farmed fish in Norwegian aquaculture for the period 2000-2005 was investigated by using prescription data. These data were validated against national sales data of AM drugs sold for use in farmed fish and were found to be highly valid. The defined course dose (DCD) was applied as the unit of measurement to correct for the variations in the dosages between different AM drugs. The DCD(kg) was the amount of an AM drug recommended for the treatment of a 1-kg fish. The calculated number of prescribed DCD(kg)s is an estimate of the biomass of farmed fish that can be treated with a certain amount AM drug. In the present study, the number of prescriptions issued (i.e., numbers of initiated treatments), weight of active substance prescribed and biomass treated were applied to describe the usage. An increase, although modest, in the AM drug usage in Norwegian aquaculture was observed from 2002 to 2005. This increase was accounted for by new-farmed fish species (other than Atlantic salmon and rainbow trout), especially Atlantic cod. The increased usage of AM drugs in cod in the study period was significantly positively correlated to the biomass produced; even so from 2001 to 2005 the number of prescriptions for cod relative to the produced biomass declined. The AM drug usage in Atlantic halibut as well as the production varied during the study period. For other species such as turbot, coalfish and wolffish the usage of AM drugs was found to be negligible. "Mono-therapy" with quinolones may present a selective pressure in regard to development of quinolone resistance.

  16. Field Trial of an Aerosol-Based Enclosure Sealing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Curtis [Univ. of California, Davis, CA (United States); Springer, David [Univ. of California, Davis, CA (United States)

    2015-09-01

    This report presents the results from several demonstrations of a new method for sealing building envelope air leaks using an aerosol sealing process developed by the Western Cooling Efficiency Center at UC Davis. The process involves pressurizing a building while applying an aerosol sealant to the interior. As air escapes through leaks in the building envelope, the aerosol particles are transported to the leaks where they collect and form a seal that blocks the leak. Standard blower door technology is used to facilitate the building pressurization, which allows the installer to track the sealing progress during the installation and automatically verify the final building tightness. Each aerosol envelope sealing installation was performed after drywall was installed and taped, and the process did not appear to interrupt the construction schedule or interfere with other trades working in the homes. The labor needed to physically seal bulk air leaks in typical construction will not be replaced by this technology. However, this technology is capable of bringing the air leakage of a building that was built with standard construction techniques and HERS-verified sealing down to levels that would meet DOE Zero Energy Ready Homes program requirements. When a developer is striving to meet a tighter envelope leakage specification, this technology could greatly reduce the cost to achieve that goal by providing a simple and relatively low cost method for reducing the air leakage of a building envelope with little to no change in their common building practices.

  17. Radiation of complex and noisy sources within enclosures

    Science.gov (United States)

    Gradoni, Gabriele; Creagh, Stephen; Tanner, Gregor

    Predicting the radiation of complex electromagnetic sources inside semi-open cavities and resonators with arbitrary geometry is a challenging topic both for physics and for engineering. We have exploited a Perron-Frobenius operator to propagate field-field correlation functions of complex and extended sources in free-space. The formula is based on a phase-space picture of the electromagnetic field, using the Wigner distribution function, and naturally captures evanescent as well as diffracted waves. This approach can be extended to study the propagation of correlation functions within cavities, with the ray-dynamical map given by the geometry of the cord connecting a point of the boundary to another. While ray methods provide an efficient way to predict average values of the correlation matrix elements, the use of random matrix theory approaches allows efficient characterisation of statistical fluctuations around these averages. Universal relations are derived and tested in the presence of dissipation for quantum maps and billiard systems. The use of this formalism is discussed in the contexts of open systems with surface roughness. The theory and achieved results are of interest in the simulation of next-generation of wireless communications. Work supported by the UK Engineering and Physical Sciences Research Council.

  18. Nutrient discharge from China’s aquaculture industry and associated environmental impacts

    Science.gov (United States)

    Zhang, Ying; Bleeker, Albert; Liu, Junguo

    2015-04-01

    China’s aquaculture industry accounts for the largest share of the world’s fishery production, and provides a principal source of protein for the nation’s booming population. However, the environmental effects of the nutrient loadings produced by this industry have not been systematically studied or reviewed. Few quantitative estimates exist for nutrient discharge from aquaculture and the resultant nutrient enrichment in waters and sediments. In this paper, we evaluate nutrient discharge from aquacultural systems into aquatic ecosystems and the resulting nutrient enrichment of water and sediments, based on data from 330 cases in 51 peer-reviewed publications. Nitrogen use efficiency ranged from 11.7% to 27.7%, whereas phosphorus use efficiency ranged from 8.7% to 21.2%. In 2010, aquacultural nutrient discharges into Chinese aquatic ecosystems included 1044 Gg total nitrogen (184 Gg N from mariculture; 860 Gg N freshwater culture) and 173 Gg total phosphorus (22 Gg P from mariculture; 151 Gg P from freshwater culture). Water bodies and sediments showed high levels of nutrient enrichment, especially in closed pond systems. However, this does not mean that open aquacultural systems have smaller nutrient losses. Improvement of feed efficiency in cage systems and retention of nutrients in closed systems will therefore be necessary. Strategies to increase nutrient recycling, such as integrated multi-trophic aquaculture, and social measures, such as subsidies, should be increased in the future. We recommend the recycling of nutrients in water and sediments by hybrid agricultural-aquacultural systems and the adoption of nutrient use efficiency as an indicator at farm or regional level for the sustainable development of aquaculture; such indicators; together with water quality indicators, can be used to guide evaluations of technological, policy, and economic approaches to improve the sustainability of Chinese aquaculture.

  19. Genetic considerations for mollusc production in aquaculture: current state of knowledge.

    Directory of Open Access Journals (Sweden)

    Marcela eAstorga

    2014-12-01

    Full Text Available IIn 2012, world mollusk production in aquaculture reached a volume of 15,171,000 tons, representing 23% of total aquaculture production and positioning mollusks as the second most important category of aquaculture products (fishes are the first. Clams and oysters are the mollusk species with the highest production levels, followed in descending order by mussels, scallops and abalones. In view of the increasing importance attached to genetic information on aquaculture, which can help with good maintenance and thus the sustainability of production, the present work offers a review of the state of knowledge on genetic and genomic information about mollusks produced in aquaculture. The analysis was applied to mollusks which are of importance for aquaculture, with emphasis on the 5 species with the highest production levels. According to FAO, these are: Japanese clam Ruditapes philippinarum; Pacific oyster Crassostrea gigas; Chilean mussel Mytilus chilensis; Blood clam Anadara granosa and Chinese clam Sinonovacula constricta. To date, the genomes of 5 species of mollusks have been sequenced, only one of which, Crassostrea gigas, coincides with the species with the greatest production in aquaculture. Another important species whose genome has been sequenced is Mytilus galloprovincialis, which is the second most important mussel in aquaculture production, after M. chilensis. Few genetic improvement programs have been reported in comparison with the number reported in fish species. The most commonly investigated species are oysters, with at least 5 genetic improvement programs reported, followed by abalones with 2 programs and mussels with one. The results of this work will establish the current situation with respect to the genetics of mollusks which are of importance for aquaculture production, in order to assist future decisions to ensure the sustainability of these resources.

  20. Eutrophication and algal blooms in channel type reservoirs: A novel enclosure experiment by changing light intensity

    Institute of Scientific and Technical Information of China (English)

    Chengjin Cao; Binghui Zheng; Zhenlou Chen; Minsheng Huang; Jialei Zhang

    2011-01-01

    To explore eutrophication and algal bloom mechanisms in channel type reservoirs,a novel enclosure experiment was conducted by changing light intensity (LI) in the Daning River of the Three Gorges Reservoir (TGR).Square enclosures (side 5.0 m) were covered on the surface with shading materials of different thickness,and with their bases open to the river.Changes and characteristics of the main eutrophication factors under the same water quality and hydrodynamic conditions but different LI were evaluated.All experimental water samples were neutral and alkalescent,with high nitrogen and phosphate concentrations,low potassium permanganate index,stable water quality,and different LI.At the same water depth,LI decreased with increasing shade material,while dissolved oxygen and water temperature were both stable.The growth peak of phytoplankton was with light of 345-4390 lux underwater or 558-7450lux above the water surface,and water temperature of 25.6-26.5℃.Algae were observed in all water samples,accounting for 6 phylum and 57 species,with algal density changing frequently.The results showed that significantly strong or weak light was unfavorable for phytoplankton growth and the function together with suitable temperature and LI and ample sunshine encouraged algal blooms under the same water quality and hydrodynamic conditions.Correlation analysis indicated that algae reduced gradually lengthwise along water depth in the same enclosure while pH became high.The power exponent relationship between chlorophyll a (Chl-a) and LI was found by curve fitting,that is Chi-a =K(LI)n.

  1. Analytical techniques for sesquiterpene emission rate studies in vegetation enclosure experiments

    Science.gov (United States)

    Helmig, Detlev; Bocquet, Florence; Pollmann, Jan; Revermann, Tobias

    Sesquiterpene (SQT) compounds (C 15H 24) and their oxygenated alcohol and ketone derivatives are biogenic volatile organic compounds that have been identified in emissions from vegetation. SQT emission rates and landscape flux estimates are highly uncertain. Reliable ambient flux measurements have not been possible because of low-ambient concentrations, rapid atmospheric reactions (prohibiting ambient tower flux measurements), and analytical challenges and uncertainties that stem from the low volatility of SQT. Standards from an in situ capillary diffusion system with 18 SQT compounds and four other organic compounds (geranylacetone, 1,3,5-tri-isopropylbenzene, diphenylmethane, nonylbenzene) were used to thoroughly investigate experimental procedures for SQT emission rate studies by vegetation enclosure techniques. Recovery rates in tubing materials, sampling bags, leaf cuvettes, on six solid adsorbent materials (Tenax TA, Tenax GR, Carbotrap, Carbotrap C, Unibeads, Glass Beads) for gas chromatography analysis, and gas chromatography retention indices and mass spectral fragmentation patterns were determined. SQT compounds were found to exhibit a high degree of stickiness to all materials tested. However, the non-oxygenated SQT can be recovered in enclosure experiments for quantitative emission rate determination after careful consideration of the analytical conditions. It is utmost important to allow sufficient purging and equilibration times for all materials in contact with the sample air. In contrast oxygenated SQT were irreversibly lost in enclosure experiments which made their quantitative measurement prohibitive. Results for the other organic compounds were similar and indicate that these data mostly stem from the volatility of these compounds. Consequently, the findings of this study provide guidelines for the analysis of a wide range of volatile organic compounds in the ˜C13-C17 volatility range.

  2. Restructuring European freshwater aquaculture from family-owned to large-scale firms

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Asche, Frank; Nielsen, Max

    2016-01-01

    Aquaculture is the world's fastest growing animal food producing sector. Although its overall performance is very good, it is unevenly spread geographically. In particular, the growth in most EU countries has been stagnating over the past 20 years despite repeated policy initiatives to launch new...... growth in the industry. The lack of production growth in EU aquaculture is often explained by strict environmental regulation and bureaucracy. In this article, we argue that an additional important element is an industry structure that limits the innovation and use of new technologies. Historically...... per kilo of fish produced has been reduced, improving future prospects for aquaculture in Denmark and Europe....

  3. Feasibility of direct utilization of selected geothermal water for aquaculture of macrobrachium rosenbergii. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Spinosa, C.

    1984-05-01

    The feasibility was tested of direct utilization of geothermal water for the aquaculture of Malaysian freshwater prawns (Macrobrachium rosenbergii). A problem with using geothermal water for aquaculture is the chemical composition of the water with high flouride levels being a particular problem. Results show that (1) some geothermal water in Idaho can be used directly for the aquaculture of Macrobrachium rosenbergii, (2) high flouride levels cannot be directly correlated with high mortality rates and (3) low flouride levels do not correlate with high growth rates.

  4. Methods for Estimating Water Withdrawals for Aquaculture in the United States, 2005

    Science.gov (United States)

    Lovelace, John K.

    2009-01-01

    Aquaculture water use is associated with raising organisms that live in water - such as finfish and shellfish - for food, restoration, conservation, or sport. Aquaculture production occurs under controlled feeding, sanitation, and harvesting procedures primarily in ponds, flow-through raceways, and, to a lesser extent, cages, net pens, and tanks. Aquaculture ponds, raceways, and tanks usually require the withdrawal or diversion of water from a ground or surface source. Most water withdrawn or diverted for aquaculture production is used to maintain pond levels and/or water quality. Water typically is added for maintenance of levels, oxygenation, temperature control, and flushing of wastes. This report documents methods used to estimate withdrawals of fresh ground water and surface water for aqua-culture in 2005 for each county and county-equivalent in the United States, Puerto Rico, and the U.S. Virgin Islands by using aquaculture statistics and estimated water-use coefficients and water-replacement rates. County-level data for commercial and noncommercial operations compiled for the 2005 Census of Aquaculture were obtained from the National Agricultural Statistics Service. Withdrawals of water used at commercial and noncommercial operations for aquaculture ponds, raceways, tanks, egg incubators, and pens and cages for alligators were estimated and totaled by ground-water or surface-water source for each county and county equivalent. Use of the methods described in this report, when measured or reported data are unavailable, could result in more consistent water-withdrawal estimates for aquaculture that can be used by water managers and planners to determine water needs and trends across the United States. The results of this study were distributed to U.S. Geological Survey water-use personnel in each State during 2007. Water-use personnel are required to submit estimated withdrawals for all categories of use in their State to the U.S. Geological Survey National

  5. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was ...... rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds. © 2012 John Wiley & Sons Ltd....

  6. Fish transposons and their potential use in aquaculture.

    Science.gov (United States)

    Tafalla, C; Estepa, A; Coll, J M

    2006-06-10

    A large part of repetitive DNA of vertebrate genomes have been identified as transposon elements (TEs) or mobile sequences. Although TEs detected to date in most vertebrates are inactivated, active TEs have been found in fish and a salmonid TE has been successfully reactivated by molecular genetic manipulation from inactive genomic copies (Sleeping Beauty, SB). Progress in the understanding of the dynamics, control and evolution of fish TEs will allow the insertion of selected sequences into the fish genomes of germ cells to obtain transgenics or to identify genes important for growth and/or of somatic cells to improve DNA vaccination. Expectations are high for new possible applications to fish of this well developed technology for mammals. Here, we review the present state of knowledge of inactive and active fish TEs and briefly discuss how their possible future applications might be used to improve fish production in aquaculture.

  7. Herbs/spices as feed additive in aquaculture

    Directory of Open Access Journals (Sweden)

    O. A. Asimi

    2013-08-01

    Full Text Available Nutrition of fish is an important consideration in fish health management of farmed finfish and shellfish. The shift in some countries from extensive to semi-intensive and intensive farming of fish demands that nutritionally complete feeds be provided by the farmer. The use of nutritionally inadequate feeds can result in reduced growth and production due to stress, but more seriously, the use of such feeds can result in loss of fish from nutritional deficiency syndromes and/or from mortality brought on by increased susceptibility of nutritionally compromised fish to infectious diseases. Medicinal plants are the main sources of natural antioxidants and antimicrobial compounds. A large number of plants have been used in traditional medicine for the treatment and control of several diseases. The present article gives an idea about the use of medicinal plants in aquaculture.

  8. Role and functions of beneficial microorganisms in sustainable aquaculture.

    Science.gov (United States)

    Zhou, Qunlan; Li, Kangmin; Jun, Xie; Bo, Liu

    2009-08-01

    This paper aims to review the development of scientific concepts of microecology and ecology of microbes and the role and functions of beneficial microorganisms in aquaculture and mariculture. Beneficial microorganisms play a great role in natural and man-made aquatic ecosystems based on the co-evolution theory in living biosphere on earth. Their functions are to adjust algal population in water bodies so as to avoid unwanted algal bloom; to speed up decomposition of organic matter and to reduce CODmn, NH3-N and NO2-N in water and sediments so as to improve water quality; to suppress fish/shrimp diseases and water-borne pathogens; to enhance immune system of cultured aquatic animals and to produce bioactive compounds such as vitamins, hormones and enzymes that stimulate growth, thus to decrease the FCR of feed.

  9. Shrimp aquaculture in low salinity water feeded with worm flavor

    Directory of Open Access Journals (Sweden)

    Wenceslao Valenzuela Quiñónez

    2012-09-01

    Full Text Available Shrimp aquaculture in Sinaloa is one of the top economic enterprises, generating many jobs and earns significant incomes every year. Shrimp feed is an essential part of maintaining healthy production. In this initial approach of shrimp growth in low salinity water, were tested two formulas of animal protein composed of 40% (APL1 and 20% (APL2 worm protein, a commercial diet, and no supplementary feed. Physicochemical parameters did not have a direct influence in shrimpbehavior. After six weeks of experimentation, shrimp fed with commercial diet had a weight gain 20% higher than those feed with worm protein. There were no significantly differences between sizes with respect to 40% animal protein and 20% animal protein with the commercial diet (P  0.05. However, shrimp fed worm protein had lower mortality. The use of worm protein could be an option to maintain a high quantity of shrimp reared in low salinity waters.

  10. Heterotrophic Bacterial Flora in Aquaculture Area around Xuejiadao

    Institute of Scientific and Technical Information of China (English)

    DU Zongjun; LI Yun; YU Dehua; WANG Xianghong; CHEN Jixiang; Robertson P.A.W.; Austin B.; XU Huaishu

    2002-01-01

    From Oct., 1999 to Oct., 2000, the heterotrophic bacterial flora in the aquaculture area around Xuejiadao wasinvestigated. The result shows that the populations of the heterotrophic bacteria are heavier in summer and autumn thanthose in winter and spring. The average populations in seawater, sediment, the surface of seaweed and the surface of fish are1.4 × 104cfu mL -1, 5.4 × 106cfu g 1, 1.5 × 106cfu g-1 and 1.8 × 103cfu cm 2, respectively. A total of 30l strains were isolated,among them 259 were Gram-negative. All the Gram-negative bacteria belong to 13 genera and some genera of Enterobacteri-aceae. The communities of bacteria are slightly different among the samples. In the body surface of fish, Genus vibrio isdominant. In the remaining samples, dominant genus is Aeromonas.

  11. Infectious diseases in oyster aquaculture require a new integrated approach

    Science.gov (United States)

    Lupo, Coralie; Whittington, Richard J.

    2016-01-01

    Emerging diseases pose a recurrent threat to bivalve aquaculture. Recently, massive mortality events in the Pacific oyster Crassostrea gigas associated with the detection of a microvariant of the ostreid herpesvirus 1 (OsHV-1µVar) have been reported in Europe, Australia and New Zealand. Although the spread of disease is often viewed as a governance failure, we suggest that the development of protective measures for bivalve farming is presently held back by the lack of key scientific knowledge. In this paper, we explore the case for an integrated approach to study the management of bivalve disease, using OsHV-1 as a case study. Reconsidering the key issues by incorporating multidisciplinary science could provide a holistic understanding of OsHV-1 and increase the benefit of research to policymakers. PMID:26880845

  12. Exergetic performance analysis of a recirculating aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Haydar [Mechanical Engineering Department, Guemueshane University, 29000 Guemueshane (Turkey); Midilli, Adnan [Energy Division, Mechanical Engineering Department. Nigde University, 51000 Nigde (Turkey); Oezdemir, Atilla; Cakmak, Eyuep [Central Fisheries Research Institute, Ministry of Agricultural and Rural Affairs, Trabzon (Turkey); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ont. (Canada)

    2010-05-15

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period. (author)

  13. Physicochemical Process, Crustacean, and Microcystis Biomass Changes In Situ Enclosure after Introduction of Silver Carp at Meiliang Bay, Lake Taihu

    Directory of Open Access Journals (Sweden)

    Chengjie Yin

    2017-01-01

    Full Text Available In order to control cyanobacteria blooms with silver carp in Lake Taihu, an in situ experiment was carried out by stocking silver carp at a biomass of 35, 70, and 150 g m-3 and no carp control in waterproof enclosures. Physicochemical water parameters and biomass of plankton were measured in enclosures to evaluate the suitable stocking density of silver carp for relieving internal nutrients and constraining cyanobacteria growth in Lake Taihu. It is found that the 35 g m-3 silver carp group and 70 g m-3 silver carp group presented lower total phosphorus, lower chlorophyll-a, and higher water transparency. Increased nitrogen to phosphorus ratio, which indicated the result of algae decline in fish presence enclosures, was attributed to decline of phosphorus. Phosphorus decline also exerted limitation on reestablish of cyanobacteria bloom. Crustacean zooplankton biomass and Microcystis biomass decreased significantly in fish presence enclosures. Silver carp could be more effective to regulate algae bloom in enclosures with dense cyanobacteria. Therefore, nonclassic manipulation is supposed to be appropriate method to get rid of cyanobacteria blooms in Lake Taihu by stocking 35 to 70 g m-3 silver carp in application.

  14. High rabbit abundance proves detrimental to the population growth rate in European rabbit (Oryctolagus cuniculus L. extensive breeding enclosures

    Directory of Open Access Journals (Sweden)

    L. Ruiz-Aizpurua

    2014-09-01

    Full Text Available The European rabbit (Oryctolagus cuniculus L. is a key prey species in Mediterranean ecosystems that has declined in its natural ranges as a result of diseases and loss of habitat. This situation has led to the production of wild rabbits in enclosures in which they can acclimate and breed. The efficiency of these enclosures as extensive breeding systems is defined by their population growth rate (PGR. The aim of this study is to analyse the effect of rabbit abundance on the PGR. This has been done by creating general linear models to explain autumn and spring PGR with the use of rabbit abundance estimates, enclosure size, aerial predation and previous PGR as possible explanatory variables. Rabbit abundance and enclosure size negatively affected the autumn PGR, while only rabbit abundance affected the spring PGR in the best-fit models. It is suggested that maintaining rabbit densities at fewer than 30 rabbits per hectare might help to optimise the efficiency inside enclosures.

  15. 退化梭梭林禁牧封育周期的研究%Timing The Recovery High - Point of Degenerted Haloxalon Ammodendron Woods by enclosure and Grazing Prohinbition

    Institute of Scientific and Technical Information of China (English)

    陶格日勒; 达来; 布日古德; 哈斯乌拉

    2014-01-01

    Aims Natural restoration by enclosure and grazing prohibition is an effective way to recover the degenerative vegetation of Haloxylon ammodendron. It,however,remains unknown of the speed and time of restoration to the best status of Haloxylon ammodendron vegetation. The enclosure of Haloxylon ammodendron vegetation in Lamajing,Alax of Inner Mongolia,was singled out to investigate the time for best restoration of Haloxylon ammodendron vegetation by an analysis of ecological features of Haloxylon ammodendron vegetation in differ-ent duration of enclosure. This study can provide scientific bases for the project of restoration of Haloxylon ammodendron vegetation and re-turn grazing to grasses. Methods According to duration of enclosure time,sample plots were divided into four sample plots,viz. 1980,1999, 2002,and 2005 sample plots. Four sample - squares are designed in the four sample plots under relatively consistent conditions of soil and topographic shape,area for each sample - square is 40m × 40m. Biomass,density,height,and coverage of Haloxylon ammodendron vegeta-tion of the four sample plots were measured. The duration for best restoration of degenerated Haloxylon ammodendron vegetation was calculat-ed using regression analysis based on data collected. Important Findings A numerical analysis indicates that the Haloxylon ammodendron veg-etation recovered best by 7 years of enclosure and grazing prohibition,the coverage of Haloxylon ammodendron is up to 22. 6% ,the density is up to 594 individuals per hectare,the biomass is up to 12. 01 kg. The density,coverage,and biomass of Haloxylon ammodendron vegeta-tion by 25 years of enclosure and grazing prohibition are inferior to those by 7 years. An analysis on age structure indicates that the Haloxylon ammodendron vegetation shows a developing tendency within 1,or 4,or 7 years of enclosure and grazing prohibition while the vegetation shew a degenerating tendency in 25 years of enclosure and grazing prohibition. A

  16. Halophyte filter beds for treatment of saline wastewater from aquaculture.

    Science.gov (United States)

    Webb, J M; Quintã, R; Papadimitriou, S; Norman, L; Rigby, M; Thomas, D N; Le Vay, L

    2012-10-15

    The expansion of aquaculture and the recent development of more intensive land-based marine farms require efficient and cost-effective systems for treatment of highly nutrient-rich saline wastewater. Constructed wetlands with halophytic plants offer the potential for waste-stream treatment combined with production of valuable secondary plant crops. Pilot wetland filter beds, constructed in triplicate and planted with the saltmarsh plant Salicornia europaea, were evaluated over 88 days under commercial operating conditions on a marine fish and shrimp farm. Nitrogen waste was primarily in the form of dissolved inorganic nitrogen (TDIN) and was removed by 98.2 ± 2.2% under ambient loadings of 109-383 μmol l(-1). There was a linear relationship between TDIN uptake and loading over the range of inputs tested. At peak loadings of up to 8185 ± 590 μmol l(-1) (equivalent to 600 mmol N m(-2) d(-1)), the filter beds removed between 30 and 58% (250 mmol N m(-2) d(-1)) of influent TDIN. Influent dissolved inorganic phosphorus levels ranged from 34 to 90 μmol l(-1), with 36-89% reduction under routine operations. Dissolved organic nitrogen (DON) loadings were lower (11-144 μmol l(-1)), and between 23 and 69% of influent DON was removed during routine operation, with no significant removal of DON under high TDIN loading. Over the 88-day study, cumulative nitrogen removal was 1.28 mol m(-2), of which 1.09 mol m(-2) was retained in plant tissue, with plant uptake ranging from 2.4 to 27.0 mmol N g(-1) dry weight d(-1). The results demonstrate the effectiveness of N and P removal from wastewater from land-based intensive marine aquaculture farms by constructed wetlands planted with S. europaea.

  17. Transition to chaos in a square enclosure containing internal heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Baytas, A.C. [Institute For Nuclear Energy, Istanbul (Turkey)

    1995-09-01

    A numerical investigation is performed to study the transition from steady to chaotic flow of a fluid confined in a two-dimensional square cavity. The cavity has rigid walls of constant temperature containing uniformly distributed internal heat source. Effects of the Rayleigh number of flow and heat transfer rates are studied. In addition to, same problem is solved for sinusoidally changing internal heat source to show its effect on the flow model and heat transfer of the enclosures. Details of oscillatory solutions and flow bifurcations are presented.

  18. Melting of nanoparticles-enhanced phase change material (NEPCM) in vertical semicircle enclosure: numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Jourabian, Mahmoud [University of Trieste, Piazzale (Italy); Farhadi, Mousa [Babol Noshirvani University of Technology, Shariati Avenue (Iran, Islamic Republic of)

    2015-09-15

    Convection melting of ice as a Phase change material (PCM) dispersed with Cu nanoparticles, which is encapsulated in a semicircle enclosure is studied numerically. The enthalpy-based Lattice Boltzmann method (LBM) combined with a Double distribution function (DDF) model is used to solve the convection-diffusion equation. The increase in solid concentration of nanoparticles results in the enhancement of thermal conductivity of PCM and the decrease in the latent heat of fusion. By enhancing solid concentration of nanoparticles, the viscosity of nanofluid increases and convective heat transfer dwindles. For all Rayleigh numbers investigated in this study, the insertion of nanoparticles in PCM has no effect on the average Nusselt number.

  19. Numerical Computation of Net Radiative Heat Transfer within a Non Absorbing Furnace Enclosure

    Directory of Open Access Journals (Sweden)

    Shuaibu Ndache MOHAMMED

    2006-07-01

    Full Text Available The numerical evaluation of the net radiative heat transfer rate in a single zone, non absorbing furnace enclosure is reported. In this analysis, simplified mathematical furnace model namely, the long furnace model is used to determine furnace performance. The formulation assumes some known temperature values. Thus, heat transfer equations were set up and solved numerically. A FORTRAN computer program was developed and debugged. Results obtained from this study compare favourably well with the results from the traditional graphical method. Also, the computer program developed can handle variations in furnace operating conditions, temperatures, thermal properties and dimensions.

  20. Toxicity induced by three antibiotics commonly used in aquaculture on the marine microalga Tetraselmis suecica (Kylin) Butch.

    Science.gov (United States)

    Seoane, Marta; Rioboo, Carmen; Herrero, Concepción; Cid, Angeles

    2014-10-01

    Aquaculture facilities are a potential source of antibiotics to the aquatic ecosystems. The presence of these compounds in the environment may have deleterious effects on non-target aquatic organisms such as microalgae, which are often used as biological indicators of pollution. Therefore, the toxicity induced by chloramphenicol (CHL), florphenicol (FLO) and oxytetracycline (OTC), three antibiotics widely used in aquaculture, on the marine microalga Tetraselmis suecica was evaluated. Growth inhibition and physiological and biochemical parameters were analysed. All three antibiotics inhibited growth of T. suecica with 96 h IC50 values of 11.16, 9.03 and 17.25 mg L(-1) for CHL, FLO and OTC, respectively. After 24 h of exposure no effects on growth were observed and cell viability was also unaffected, whereas a decrease in esterase activity, related with cell vitality, was observed at the higher concentrations assayed. Photosynthesis related parameters such as chlorophyll a cellular content and autofluorescence were also altered after 24 h of antibiotics addition. It can be concluded that T. suecica was sensitive to the three antibiotics tested.