WorldWideScience

Sample records for net fish farming

  1. Copper in the sediment and sea surface microlayer near a fallowed, open-net fish farm.

    Science.gov (United States)

    Loucks, Ronald H; Smith, Ruth E; Fisher, Clyde V; Fisher, E Brian

    2012-09-01

    Sediment and sea surface microlayer samples near an open-net salmon farm in Nova Scotia, were analysed for copper. Copper is a constituent of the feed and is an active ingredient of anti-foulants. The salmon farm was placed in fallow after 15 years of production. Sampling was pursued over 27 months. Elevated copper concentrations in the sediments indicated the farm site as a source. Bubble flotation due to gas-emitting sediments from eutrophication is a likely process for accumulating copper in the sea surface microlayer at enriched concentrations. Elevated and enriched concentrations in the sea surface microlayer over distance from the farm site led, as a result of wind-drift, to an enlarged farm footprint. The levels of copper in both sediments and sea surface microlayer exceeded guidelines for protection of marine life. Over the 27 months period, copper levels persisted in the sediments and decreased gradually in the sea surface microlayer. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. First testing of an AUV mission planning and guidance system for water quality monitoring and fish behavior observation in net cage fish farming

    Directory of Open Access Journals (Sweden)

    D. Karimanzira

    2014-12-01

    Full Text Available Recently, underwater vehicles have become low cost, reliable and affordable platforms for performing various underwater tasks. While many aquaculture systems are closed with no harmful output, open net cage fish farms and land-based fish farms can discharge significant amounts of wastewater containing nutrients, chemicals, and pharmaceuticals that impact on the surrounding environment. Although aquaculture development has often occurred outside a regulatory framework, government oversight is increasingly common at both the seafood quality control level, and at baseline initiatives addressing the basic problem of pollution generated by culture operations, e.g. the European marine and maritime directives. This requires regular, sustainable and cost-effective monitoring of the water quality. Such monitoring needs devices to detect the water quality in a large sea area at different depths in real time. This paper presents a concept for a guidance system for a carrier (an autonomous underwater vehicle of such devices for the automated detection and analysis of water quality parameters.

  3. Should You Attempt Fish Farming? Considerations for Prospective Fish Growers

    OpenAIRE

    Helfrich, Louis A. (Louis Anthony), 1942-; Libey, George S., 1942-

    2009-01-01

    Provides lists of the most important factors to consider in determining whether you should begin a fish farming business, fish farming publications, fish farming books, and fish farming organizations.

  4. Countermeasures against viral diseases of farmed fish.

    Science.gov (United States)

    Kibenge, Frederick S B; Godoy, Marcos G; Fast, Mark; Workenhe, Samuel; Kibenge, Molly J T

    2012-09-01

    Farmed fish provide an increasing fraction of the human food supply, and are of major economic importance in many countries. As in the case of terrestrial agriculture, bringing together large numbers of animals of a single species (i.e., monoculture) increases the risk of infectious disease outbreaks, including viral infections. Aquaculture, in which farmed fish are kept at high population densities in close proximity with wild fish reservoirs, is ideal for the emergence of wild-type pathogens that exist benignly in local wild fish and/or the spreading of aquatic pathogens to wild fish that enter into or come into close proximity with net cages and with fish escaping from them. This paper provides a general review for the nonspecialist of viral diseases of farmed fish and how they could be prevented or treated. It has five principal objectives: (1) to provide an update on the most important and emerging viral diseases of salmonid aquaculture; (2) to review general aspects of innate antiviral defense against virus infections in fish, including recent advances in antiviral signaling; (3) to discuss current principles and practices of vaccinating fish; (4) to review antiviral drugs that have activity against viruses of farmed fish, and current barriers to employing them in aquaculture; and (5) to discuss the growing use of "functional feeds" in salmonid aquaculture to mitigate viral diseases. In conclusion, despite the challenging aquatic environment, it is expected that well thought-out combinations of vaccination and immunostimulants and/or antiviral drugs could provide solid protection against viral diseases of farmed fish. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. 50 CFR 14.23 - Live farm-raised fish and farm-raised fish eggs.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Live farm-raised fish and farm-raised fish... Exportation at Designated Ports § 14.23 Live farm-raised fish and farm-raised fish eggs. Live farm-raised fish... for wildlife requiring a permit pursuant to parts 17 or 23 of this subchapter, live farm-raised fish...

  6. Consumer perceptions of farmed fish

    NARCIS (Netherlands)

    Reinders, Machiel J.; Banović, Marija; Guerrero, Lluis; Krystallis, Athanasios

    2016-01-01

    Purpose: The purpose of this paper is to investigate possible cross-cultural consumer segments in the EU aquaculture market and provide direction and focus for marketing strategies for farmed fish products. Design/methodology/approach: Selected psychographic constructs (i.e. category involvement,

  7. Effect of artificial light on marine invertebrate and fish abundance in an area of salmon farming

    National Research Council Canada - National Science Library

    A. McConnell; R. Routledge; B. M. Connors

    2010-01-01

    .... Open net-pen salmon farms in British Columbia, Canada, routinely illuminate their net-pens during the winter and spring, with unknown consequences on the abundance and distribution of marine fish and invertebrates...

  8. Biofilm responses to marine fish farm wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sanz-Lazaro, Carlos, E-mail: carsanz@um.es [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain); Navarrete-Mier, Francisco; Marin, Arnaldo [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain)

    2011-03-15

    The changes in the biofilm community due to organic matter enrichment, eutrophication and metal contamination derived from fish farming were studied. The biofilm biomass, polysaccharide content, trophic niche and element accumulation were quantified along an environmental gradient of fish farm wastes in two seasons. Biofilm structure and trophic diversity was influenced by seasonality as well as by the fish farm waste load. Fish farming enhanced the accumulation of organic carbon, nutrients, selenium and metals by the biofilm community. The accumulation pattern of these elements was similar regardless of the structure and trophic niche of the community. This suggests that the biofilm communities can be considered a reliable tool for assessing dissolved aquaculture wastes. Due to the ubiquity of biofilms and its wide range of consumers, its role as a sink of dissolved wastes may have important implications for the transfer of aquaculture wastes to higher trophic levels in coastal systems. - Research highlights: > Biofilms can act as a trophic pathway of fish farm dissolved wastes. > Biofilms are reliable tools for monitoring fish farm dissolved wastes. > The influence of the fish farm dissolved wastes can be detected 120-350 m from farm. - Under the influence of fish farming biofilm accumulates organic carbon, nutrients, selenium and metals, regardless of the structure and trophic niche of the community.

  9. Current situation of fish farming in Togo

    African Journals Online (AJOL)

    In Togo, fish farming is faced with several problems which oblige farmers to develop local production techniques that explain the low level of production. To assess the current situation, a survey was conducted to collect information on this activity in 91 Togolese fish farms located in the five regions of the country. The.

  10. Behavioural indicators of welfare in farmed fish

    NARCIS (Netherlands)

    Martins, C.I.; Galhardo, L.; Noble, C.; Damsgard, B.; Spedicato, M.T.; Zupa, W.; Beauchaud, M.; Kulczykowska, E.; Massabuau, J.C.; Carter, T.; Planellas, S.R.; Kristiansen, T.

    2012-01-01

    Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in

  11. Fish benefits from offshore wind farm development

    DEFF Research Database (Denmark)

    Leonhard, Simon B.; Stenberg, Claus; Støttrup, Josianne

    2013-01-01

    moderately attractive to fish. Also investigations into the effects on fish and fish behaviour from electromagnetic fields were made at Nysted. Data documented some effects from the cable route on fish behaviour, with some species avoiding the cable, while other species were attracted. However, only flounder......The studies up until 2006 showed few effects on the fish fauna that could be attributed to the establishment and operation of the wind farms. Fish abundance and diversity were not higher inside the wind farms than in the areas outside the wind farms. One obvious reason for this could...... be that the studies and investigations were made during the early stages of colonisation of the turbine foundations at Horns Rev that constitute artificial reefs. At Nysted, the effect was weak, presumably because the benthic community consisted of a monoculture of large common mussels (Mytilus edulis) that are only...

  12. Consumer beliefs regarding farmed versus wild fish.

    Science.gov (United States)

    Claret, Anna; Guerrero, Luis; Ginés, Rafael; Grau, Amàlia; Hernández, M Dolores; Aguirre, Enaitz; Peleteiro, José Benito; Fernández-Pato, Carlos; Rodríguez-Rodríguez, Carmen

    2014-08-01

    Aquaculture is a food-producing activity, alternative to traditional extractive fishing, which still acts as a reference for most consumers. The main objective of the present paper was to study which consumer beliefs, regarding farmed versus wild fish, hinder the potential development of the aquaculture sector. To achieve this purpose the study was organized into two complementary steps: a qualitative approach (focus groups) aimed at assessing consumer perception about wild and farmed fish and to identify the salient beliefs that differentiate them; and a quantitative approach (survey by means of a questionnaire) to validate the results obtained in the focus group discussions over a representative sample of participants (n = 919). Results showed that participants perceive clear differences between farmed and wild fish. Although no significant differences between both kinds of fish were detected on safety, in general farmed fish was perceived to be less affected by marine pollution, heavy metals and parasites. In the contrary, wild fish was considered to have healthier feeding, to contain fewer antibiotics and to be fresher, healthier, less handled and more natural. Beliefs related to quality were in favour of wild fish, while those related to availability and price were in favour of farmed fish. Significant differences were observed in the perception of both kinds of fish depending on the consumers' objective knowledge about fish, on the level of education, age and gender and on the three segments of consumers identified: "Traditional/Conservative", "Connoisseur", "Open to aquaculture". The results provided could play an important role when planning and designing efficient marketing strategies for promoting farmed fish by adapting the information provided to the perception of each segment of consumers identified by the present study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Economics of Fish Farming In Imo State, Nigeria | Obasi | Journal of ...

    African Journals Online (AJOL)

    The primary objective of the study was to identify an appropriate fish production system necessary to ensure efficient resource utilization in fish farming in Imo State. The sample size comprised 31 fish farmers who were randomly selected and interviewed. The results of the analysis show that the net returns were ...

  14. Nets, Boats and Fishing in the Roman World

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2002-01-01

    Ithas been claimed that in Roman times, net fishing was a shore-based technology, but a study of literary sources and pictorial evidence, mainly mosaics, show that net fishing from boats was widespread throughout the first four centuries AD.......Ithas been claimed that in Roman times, net fishing was a shore-based technology, but a study of literary sources and pictorial evidence, mainly mosaics, show that net fishing from boats was widespread throughout the first four centuries AD....

  15. Using NetLogo in the Data Farming Environment

    OpenAIRE

    Koehler, Matthew

    2006-01-01

    from Scythe : Proceedings and Bulletin of the International Data Farming Community, Issue 1 Workshop 13 NetLogo is a freely available agent-based modeling environment being developed by Northwestern University’s Center for Connected Learning (ccl.northwestern.edu/ netlogø). NetLogo is an excellent environment for creating simpler or smaller-scale agent-based models or prototyping more complex models. NetLogo’s strengths include using a very easy to learn and flexible ...

  16. Fish farm management practices in Nigeria | Omitoyin | African ...

    African Journals Online (AJOL)

    Abstract. Fish farming can contribute significantly to national food security; alleviate malnutrition and poverty. However, its potential is yet to be fully tapped. Higher productivity in fish farming can be achieved through proper farm management. No matter how well constructed a fish farm is, without adequate management the ...

  17. PHYTOPLANKTON COMPOSITION IN FISH FARMS ALONG THE EASTERN ADRIATIC COAST

    Directory of Open Access Journals (Sweden)

    Marija Tomec

    2006-10-01

    Full Text Available Investigations of net phytoplankton composition were performed at three fish farms situated at the northern, middle and southern part of the eastern Adriatic Sea coast, respectively. In the northern part investigations were conducted in the Limski kanal, in the middle part at the Ugljan island and in the southern part in the place Drače on the Pelješac peninsula (Figure 1. At all three localities fish culture included mostly two species: gilthead sea bream (Sparus aurata and sea bass (Dicentrarchus labrax. Beside some physico–chemical parameters (sea water temperature, salinity special attention was placed on the examination of qualitative net phytoplankton composition, which was conducted in the period of May and November 2004 and May and October 2005. Samples were collected at the depths of 0. 5 and 4 meters. According to the physico–chemical parameters, sea water temperature was influenced by the temperature of the environment. Qualitative net phytoplankton composition consisted of 153 microphytic species belonging to the systematic compartments of Cyanobacteria, Chrysophyta and Dinophyta (Table 1. The most numerous algal group were diatoms or Bacillarophyceae (84 species or 55% with relative frequencies of species from 1 to 7. Taxonomic composition of diatoms showed the community Chaetoceros–Rhizosolenia (Proboscia as the dominant one. The second numerically most dominant compartment were Dinophyta (62 species or 401% with dominant the species of the genera Ceratium and Protoperidinium. Relative frequencies of species was ranging from 1 to 7 (mass presence of specimens in the water column. From Cyanobacteria (4 species or 3%, only filamentous algae were determined, with individual presence in net phytoplankton composition. Qualitative net phytoplankton composition suggests the similarity of species composition in the water column at all investigated fish farms. From the obtained characteristics of net phytoplankton composition

  18. Behavioural indicators of welfare in farmed fish.

    Science.gov (United States)

    Martins, Catarina I M; Galhardo, Leonor; Noble, Chris; Damsgård, Børge; Spedicato, Maria T; Zupa, Walter; Beauchaud, Marilyn; Kulczykowska, Ewa; Massabuau, Jean-Charles; Carter, Toby; Planellas, Sònia Rey; Kristiansen, Tore

    2012-02-01

    Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e.g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e.g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near

  19. Recycled fishing nets as reinforcement of existing concrete structures

    DEFF Research Database (Denmark)

    Sigvardsen, Nina Marie; Bonnerup, Amanda Helena; Ottosen, Lisbeth M.

    2016-01-01

    Large amounts of fishing nets are discarded every year polluting the oceans with plastic fibers on a global scale. Due to the big fishing industry in Greenland, an alternative use for discarded fishing nets would have a decreasing effect on the amount of marine litter in the Arctic. A use...

  20. Net Farm Income Analysis of Maize Production in Gwagwalada Area ...

    African Journals Online (AJOL)

    This study examined net farm income of maize production in Gwagwalada Area Council of Federal Capital Territory. The specific objectives are to: identify the socio-economic characteristics of maize farmers in the study area, evaluate the costs and returns of maize production in the study area, and evaluate factors affecting ...

  1. Fishing with bed nets on Lake Tanganyika: a randomized survey.

    Science.gov (United States)

    McLean, Kate A; Byanaku, Aisha; Kubikonse, Augustine; Tshowe, Vincent; Katensi, Said; Lehman, Amy G

    2014-10-07

    Malaria is among the most common causes of death along Lake Tanganyika, a problem which many aid organizations have attempted to combat through the distribution of free mosquito bed nets to high-risk communities. The Lake Tanganyika Floating Health Clinic (LTFHC), a health-based non-governmental organization (NGO), has observed residents of the Lake Tanganyika basin using bed nets to fish small fry near the shoreline, despite a series of laws that prohibit bed net use and other fine-gauge nets for fishing, implemented to protect the near-shore fish ecology. The LTFHC sought to quantify the sources of bed nets and whether they were being used for fishing. The LTFHC conducted a survey of seven lakeside villages in Lagosa Ward, Tanzania. The government has divided each village into two to six pre-existing geographic sub-villages depending on population size. Seven households per sub-village were chosen at random for survey administration. The survey consisted of 23 questions regarding mosquito bed net practices, including the use of bed nets for fishing, as well as questions pertaining to any perceived changes to the fish supply. A total of 196 surveys were administered over a four-week period with a 100% response rate. Over 87% of households surveyed have used a mosquito bed net for fishing at some point. The majority of respondents reported receiving their bed net for free (96.4%), observing "many" residents of their village using bed nets for fishing (97.4%), and noticing a subjective decrease in the fish supply over time (64.9%). The findings of this study raise concerns that the use of free malaria bed nets for fishing is widespread along Lake Tanganyika, and that this dynamic will have an adverse effect on fish ecology. Further studies are indicated to fully define the scope of bed net misuse and the effects of alternative vector control strategies in water-based communities.

  2. Common fish diseases and parasites affecting wild and farmed

    African Journals Online (AJOL)

    ACSS

    leading to economic losses to commercial fish farms and associated natural aquatic ecosystems. This survey assessed health profiles of selected commercial fish farms and adjacent natural aquatic ecosystemsto identify fish diseases ... fish deficit (Dickson et al., 2012; Nunan,. 2014). Cases of aquatic diseases incidences.

  3. Health risks of workers fish farming center

    Directory of Open Access Journals (Sweden)

    Jorge L. Minchola Gallardo

    2013-12-01

    Full Text Available In this study we evaluated the ergonomic risks in workers' health Fish Farming Center. The sample universe consisted of the 15 workers of Motil Fish Farming Center, Department of La Libertad, Peru. Samples were taken every month. The methods used to assess ergonomic ergonomic risk were: Job Strain Index (JSI, Rapid Entire Body Assessment (REBA and Oako Working Analysis System (OWAS. The Results demonstrated by the methods of JSI and REBA that selection and maintenance activities are generating greater risks, and, according to the method OWAS, the activity that generates higher risks is that of selection, followed by selection activities of gravid females and maintenance. It was concluded that the activities that need immediate corrective measures are the selection and maintenance.

  4. Engineering properties of fibres from waste fishing nets

    DEFF Research Database (Denmark)

    Bertelsen, Ida Maria Gieysztor; Ottosen, Lisbeth M.

    2016-01-01

    This study is part of the international project Circular Ocean and focuses on reducing marine plastic waste within the Northern Periphery and Arctic (NPA) region by developing new sustainable solutions for the reuse of discarded waste fishing nets. Recycled plastic fibres from waste fishing nets...

  5. Effect of fish farming on household food security in western Kenya ...

    African Journals Online (AJOL)

    This study examined the impact of fish farming on household food security and livelihoods of fish farming and non-fish farming households in Siaya County. Fish farming involves raising fish commercially in tanks or enclosures, usually for food. Currently fish farming remains under developed in Western Kenya where pond ...

  6. Common fish diseases and parasites affecting wild and farmed ...

    African Journals Online (AJOL)

    Intensification of aquaculture production in Uganda is likely to result into disease out-breaks leading to economic losses to commercial fish farms and associated natural aquatic ecosystems. This survey assessed health profiles of selected commercial fish farms and adjacent natural aquatic ecosystemsto identify fish ...

  7. Adoption of Green River Project Fish Farming Technologies by ...

    African Journals Online (AJOL)

    The study assessed adoption of improved fish farming technologies by fish farmers as well as socioeconomic characteristics of respondents, level of adoption of GRP fish farming technologies and constraints to adoption of the technologies. The hypothesis of the study was that socioeconomic conditions of farmers do not ...

  8. RESEARCH OF SYSTEMS FOR WATER OXYGEN ENRICHMENT ON FISH FARM

    Directory of Open Access Journals (Sweden)

    Adnan Jažić

    2013-01-01

    Full Text Available Research of systems for oxygen enrichment of the water on the fish farms was carried out at the salmon farm, providing information on the practical application of the devices for oxygen enrichment of the water (sprinkler given the fact the salmon farm in question constantly faces the problem of reduced water inflow and consequent reduced concentration of oxygen (O2 in water. The aforementioned could result in lowered economic profitability of the production as well as serious health problems of fish on the farms. The role of the devices for efficient oxygen enrichment of water within the systems for intensive fish farming is to control and maintain optimal concentration of oxygen as a precondition for quality production, improvement of health and quality of fish, and to allow fish breeding in the fish farms during the drought season, lowered water levels in waterbeds and reduced inflow. Key words : Rainbow trout, oxygen, water sprinkler

  9. Species-specific patterns of aggregation of wild fish around fish farms

    Science.gov (United States)

    Dempster, T.; Sanchez-Jerez, P.; Uglem, I.; Bjørn, P.-A.

    2010-01-01

    Fish-farming structures are widespread in coastal waters and are highly attractive to wild fish. Several studies have estimated that tons to tens of tons of wild fish aggregate around fish farms. These estimates assumed that the majority of wild fish are concentrated immediately beneath farms, although this assumption has never been explicitly tested. We tested the hypothesis that abundances of wild fish would be greatest immediately beneath farms and progressively diminish with distance at 4 full-scale coastal salmon ( Salmo salar) farms in Norway. At each farm, fish were counted with a video-camera system at 5 different distances from the cages (farm = 0 m, 25, 50, 100 and 200 m) throughout the water column on three separate days. Combined across all locations and times, the total abundance of wild fish was 20 times greater at the farm than at the 200 m sampling distance. Saithe ( Pollachius virens) dominated assemblages at all 4 farms and were consistently significantly more abundant at the farm than at the 25-200 m distances. This 'tight aggregation' around farms corresponds to the reliance of saithe on waste feed when they school near farms. In contrast, patterns of distribution of both cod ( Gadus morhua) and poor cod ( Trisopterus minutus) varied among farms, with either highest abundances at the farm or a more even distribution of abundance across all 5 distances sampled. No specific pattern of aggregation was evident for the bottom-dwelling haddock ( Melanogrammus aeglefinus). Our results suggest that the present 100 m no-fishing zone around salmon farms protects the greatest proportion of farm-aggregated saithe and cod from fishing during the daytime. However, whether this reduces their overall susceptibility to fishing requires further research regarding nighttime distribution and movements.

  10. Current situation of fish farming in Togo | Adjanke | International ...

    African Journals Online (AJOL)

    In Togo, fish farming is faced with several problems which oblige farmers to develop local production techniques that explain the low level of production. To assess the current situation, a survey was conducted to collect information on this activity in 91 Togolese fish farms located in the five regions of the country. The survey ...

  11. Fish farms at sea: the ground truth from Google Earth.

    Directory of Open Access Journals (Sweden)

    Pablo Trujillo

    Full Text Available In the face of global overfishing of wild-caught seafood, ocean fish farming has augmented the supply of fresh fish to western markets and become one of the fastest growing global industries. Accurate reporting of quantities of wild-caught fish has been problematic and we questioned whether similar discrepancies in data exist in statistics for farmed fish production. In the Mediterranean Sea, ocean fish farming is prevalent and stationary cages can be seen off the coasts of 16 countries using satellite imagery available through Google Earth. Using this tool, we demonstrate here that a few trained scientists now have the capacity to ground truth farmed fish production data reported by the Mediterranean countries. With Google Earth, we could examine 91% of the Mediterranean coast and count 248 tuna cages (circular cages >40 m diameter and 20,976 other fish cages within 10 km offshore, the majority of which were off Greece (49% and Turkey (31%. Combining satellite imagery with assumptions about cage volume, fish density, harvest rates, and seasonal capacity, we make a conservative approximation of ocean-farmed finfish production for 16 Mediterranean countries. Our overall estimate of 225,736 t of farmed finfish (not including tuna in the Mediterranean Sea in 2006 is only slightly more than the United Nations Food and Agriculture Organization reports. The results demonstrate the reliability of recent FAO farmed fish production statistics for the Mediterranean as well as the promise of Google Earth to collect and ground truth data.

  12. Prevalence of fish diseases in fish farms in Katsina State, Nigeria ...

    African Journals Online (AJOL)

    Prevalence of fish disease in fish farms in Nigeria was investigated using data from structured questionnaire obtained during farm visits, and analysed using descriptive statistics and multiple linear regression. Findings from the study revealed that majority of the farm manager's (45.7) have less than 3 years of experience in ...

  13. Investigations on the porous resistance coefficients for fishing net structures

    DEFF Research Database (Denmark)

    Chen, Hao; Christensen, Erik Damgaard

    2016-01-01

    resistance coefficients were adjusted by fitting the available experimental data. In the present paper, a new approach was proposed to calculate the porous resistance coefficients based on the transformation of Morison type load model. The transformation follows the principle that the total forces acting...... validation cases were carried out to examine the performance of the numerical model. This includes steady current flow through plane net panels and circular fish cages, and wave interaction with plane net panels. A variety of fishing nets with different solidity ratios were used in the validation cases, from...

  14. Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area, China.

    Science.gov (United States)

    Zhang, L X; Ulgiati, S; Yang, Z F; Chen, B

    2011-03-01

    Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer's decisions, the accessibility of land for the required use and investment ability determine the farmer's choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making. Copyright © 2010

  15. Consumer perception versus scientific evidence of farmed and wild fish

    DEFF Research Database (Denmark)

    Verbeke, Wim; Sioen, Isabelle; Brunsø, Karen

    2007-01-01

    The increasing number of marketable fish being supplied from aquaculture is a response to the increasing demand for healthy food and is filling the gap left by depleting natural fish stocks. Little is known about the awareness and perception of the consumer in terms of farmed fish versus fish from...... capture fisheries. The consumer's subjective point of view is of overriding importance for the production system and product acceptance as well as for future market success. In this paper consumer perception in Belgium is explored and compared against scientific evidence of farmed versus wild fish....... Primary data were collected through a consumer survey (April 2003) and focus group discussions (May 2004) with Belgian consumers. The majority of the consumer sample reported no perceived differences between farmed versus wild fish. However, mean perception scores were slightly in favour of wild fish...

  16. Women's Involvement In Fish Farming: Access To Agricultural ...

    African Journals Online (AJOL)

    These showed that women involved in fish farming need wide ranged of information in fish processing, storage and preservation, loan and credit facilities and modern fishing equipment. The main information sources/channels used by the respondent were town criers, community meetings, personal experience; radio, ...

  17. Grassroots Women Empowerment and Participation in Fish Farming ...

    African Journals Online (AJOL)

    102 women fish farmers were drawn from the two communities with simple random sampling. Also, 14 women fish farmers were purposively selected for focus group discussion (FGD) in each of the communities. The result shows that a considerable majority of the women engaged in full-time fish farming; in addition to their ...

  18. Using stable isotope systematics and trace metals to constrain the dispersion of fish farm pollution

    Science.gov (United States)

    Torchinsky, A.; Shiel, A. E.; Price, M.; Weis, D. A.

    2010-12-01

    Fish farming is a growing industry of great economic importance to coastal communities. Unfortunately, open-net fish farming is associated with the release of organic and metal pollution, which has the potential to adversely affect the coastal marine environment. The dispersion of fish farm pollution and its environmental impact are not well understood/quantified. Pollutants released by fish farms include organic products such as uneaten feed pellets and fish feces, as well as chemicals and pharmaceuticals, all of which may enter marine ecosystems. In this study, we took advantage of bioaccumulation in passive suspension feeding Manila Clams collected at varying distances from an open-net salmon farm located in the Discovery Islands of British Columbia. Measurements of stable C and N isotopes, as well as trace metal concentrations, in the clams were used to investigate the spread of pollutants by detecting the presence of fish farm waste in the clams’ diet. Lead isotopic measurements were used to identify other significant anthropogenic pollution sources, which may impact the study area. Clams located within the areal extent of waste discharged by a fish farm are expected to exhibit anomalous light stable isotope ratios and metal concentrations, reflecting the presence of pollutants accumulated directly from seawater and from their diet. Clams were collected in the Discovery Islands from three sites in the Octopus Islands, located 850 m, 2100 m and 3000 m north of the Cyrus Rocks salmon farm (near Quadra Island) and from a reference site on Penn Island. Light stable isotope ratios (δN = ~10‰, with little variation between sites, and δC from -14.5 to -17.3‰) of the clams suggest that the most distal site (i.e., 3000 m away) is most impacted by organic fish farm waste (i.e., food pellets and feces) and that contributions of organic waste actually decrease closer to the farm. Not surprisingly, the smallest contribution of organic waste was detected in clams

  19. Health Categorisation of Fish Farms in Europe In 2011

    DEFF Research Database (Denmark)

    Olesen, Niels Jørgen; Nicolajsen, Nicole

    2012-01-01

    The Questionnaire on Surveillance and Diagnosis (S&D) included questions on how fish farms are health categorised according to Council Directive 2006/88/EC in the respective countries. More than half of the authorised farms in Europe are in category III for VHS and IHN and the remaining in category...... I or II. According to these official data almost no farms are infected with either of these diseases. This might be more due to a significant underreporting than of the de facto situation. For KHV most carp farms are in category III, unknown status. Many farms in Europe are not categorised yet...

  20. Impact of Fish Farming on Phosphorus in Reservoir Sediments.

    Science.gov (United States)

    Jia, Binyang; Tang, Ya; Tian, Liyan; Franz, Leander; Alewell, Christine; Huang, Jen-How

    2015-11-18

    Fish farming has seriously influenced the aquatic environment in Sancha reservoir in SW China since 1985 and has been strongly restricted since 2005. Thus, phosphorus speciation in a sediment core dated between 1945 and 2010 at cm-resolution and in surface sediments from Sancha reservoir may allow us track how fish farming impacts phosphorus dynamics in lake sediments. Fish farming shifts the major binding forms of phosphorus in sediments from organic to residual phosphorus, which mostly originated from fish feed. Sorption to metal oxides and association with organic matters are important mechanisms for phosphorus immobilisation with low fish farming activities, whereas calcium-bound phosphorous had an essential contribution to sediment phosphorus increases under intensive fish framing. Notwithstanding the shifting, the aforementioned phosphorus fractions are usually inert in the lake environment, therefore changing phosphorus mobility little. The use of fish feed and water-purification reagents, the most important additives for fish farming, introduce not only phosphorus but also large amounts of sand-sized minerals such as quartz into the lake, to which phosphorus weakly sorbs. The sand-sized minerals as additional sorbents increase the pool of easily mobilisable phosphorus in sediments, which will slow down the recovery of reservoir water due to its rapid re-mobilisation.

  1. Impact of Fish Farming on Phosphorus in Reservoir Sediments

    Science.gov (United States)

    Jia, Binyang; Tang, Ya; Tian, Liyan; Franz, Leander; Alewell, Christine; Huang, Jen-How

    2015-01-01

    Fish farming has seriously influenced the aquatic environment in Sancha reservoir in SW China since 1985 and has been strongly restricted since 2005. Thus, phosphorus speciation in a sediment core dated between 1945 and 2010 at cm-resolution and in surface sediments from Sancha reservoir may allow us track how fish farming impacts phosphorus dynamics in lake sediments. Fish farming shifts the major binding forms of phosphorus in sediments from organic to residual phosphorus, which mostly originated from fish feed. Sorption to metal oxides and association with organic matters are important mechanisms for phosphorus immobilisation with low fish farming activities, whereas calcium-bound phosphorous had an essential contribution to sediment phosphorus increases under intensive fish framing. Notwithstanding the shifting, the aforementioned phosphorus fractions are usually inert in the lake environment, therefore changing phosphorus mobility little. The use of fish feed and water-purification reagents, the most important additives for fish farming, introduce not only phosphorus but also large amounts of sand-sized minerals such as quartz into the lake, to which phosphorus weakly sorbs. The sand-sized minerals as additional sorbents increase the pool of easily mobilisable phosphorus in sediments, which will slow down the recovery of reservoir water due to its rapid re-mobilisation. PMID:26577441

  2. Status and prospects of fish farming in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.; Verlecar, X.N.

    -cum-prawn culture. Relevant information on the indigenous methods of cultivating common species, their annual yield and economics of aquaculture are discussed in the paper with reference to future prospects of fish farming in Goa...

  3. Coping styles in farmed fish: consequences for aquaculture

    OpenAIRE

    Castanheira, Maria Filipa; Conceicao, Luis E.C.; Millot, Sandie; Rey, Sonia; Begout, Marie-laure; Damsgard, Borge; Kristiansen, Tore; Hoglund, Erik; Overli, Oyvind; Martins, Catarina I.M.

    2017-01-01

    Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is present in all vertebrate taxa including fish. In farmed animals, the interest in consistent trait associations, that is coping styles, has increased dramatically over the last years because many studies h...

  4. Determinants of net return among fish marketers in Port Harcourt ...

    African Journals Online (AJOL)

    The ordinary least squares multiple regression technique was also used to estimate the determinants of net returns of the marketers. The result showed that fish marketing in the area is profitable and has a return on investment of N1.17. Educational level and marketing experience positively and significantly influenced the ...

  5. Economics of fish farming in Ibadan Metropolis | Yusuf | Nigerian ...

    African Journals Online (AJOL)

    The study assesses the economics of fish farming in Ibadan Metropolis. The data for the study were collected from 50 fish farmers with the aid of structured questionnaires. The data were analyses using descriptive, gross margin and regression techniques. The study revealed that most farmers had secondary education and ...

  6. Defining, assessing and promoting the welfare of farmed fish.

    Science.gov (United States)

    Huntingford, F A; Kadri, S

    2014-04-01

    As currently practised, the culture of fish for food potentially raises concerns about the welfare of farmed fish, and this is a topic that has received considerable attention. As vertebrates, fish share a number of features with the birds and mammals that are more commonly farmed, so many welfare principles derived from consideration of these groups may also be applied to fish. However, fish have a long, separate evolutionary history and are also adapted to a very different, aquatic environment. For these reasons, they have a number of special features that are relevant to how welfare is defined, assessed and promoted and these are discussed. The various methods that are available to researchers for identifying and assessing good and bad welfare in fish are considered, including assessment of physical health and physiological, behavioural and genomic status. The subset of practical welfare indicators that can be used on working farms is also reviewed. Various aspects of intensive aquaculture that can potentially compromise fish welfare are outlined, as are some strategies available for mitigating such adverse effects. Finally, the paper ends by looking briefly to the future, identifying likely changes in aquaculture practices and how these might affect the welfare of farmed fish.

  7. Unforeseen misuses of bed nets in fishing villages along Lake Victoria

    Directory of Open Access Journals (Sweden)

    Futami Kyoko

    2008-08-01

    Full Text Available Abstract Background To combat malaria, the Kenya Ministry of Health and nongovernmental organizations (NGOs have distributed insecticide-treated nets (ITNs for use over beds, with coverage for children under five years of age increasing rapidly. Nevertheless, residents of fishing villages have started to use these bed nets for drying fish and fishing in Lake Victoria. This study investigated the extent of bed net misuse in fishing villages. Methods Seven fishing villages along the lake were surveyed to estimate how widely bed nets were being used for fishing and drying fish. Villagers were asked why they used the bed nets for such purposes. Results In total, 283 bed nets were being used for drying fish. Of these, 239 were long-lasting insecticidal bed nets (LLIN and 44 were non-long-lasting insecticidal bed nets (NLLIN. Further, 72 of the 283 bed nets were also being used for fishing. The most popular reasons were because the bed nets were inexpensive or free and because fish dried faster on the nets. LLINs were preferred to NLLINs for fishing and drying fish. Conclusion There is considerable misuse of bed nets for drying fish and fishing. Many villagers are not yet fully convinced of the effectiveness of LLINs for malaria prevention. Such misuses may hamper the efforts of NGOs and governmental health organizations.

  8. FRESHWATER FISH FARMING CONDITIONS IN 1999 AND THE PRODUCTION PLAN FOR 2000

    Directory of Open Access Journals (Sweden)

    Zlatko Homen

    2000-09-01

    at 7.945,43 tons of the freshwater fish, of which 7.173,33 tons are warm-water fish species, and 772,10 tons are cold-water species. Carp farming is the most dominante and most significant production branch in both of the years mentioned. Distribution of the produced freshwater fish was conducted as follows. The largest quantity of the produced fish was placed on the market through wholesale (48,51 percent. This was fallowed by the distribution of produced fish for reproduction purposes (plantation which comprises 40,25 percent. Retail trade claimed 4,39 percent and personal use recorded (recreatinal fishing 2,04 percent. Production losses due to diseases or other factors made up 4,81 percent of the overall production. The overall areas of the fish farms in 1999 were 11.921.06 hectares. The actual production sites made up 9.782 hectares. Compared to 1998, the overall areas decreased for 5,84 percentt, while the production sites were increased by 0,94 percent. When taking into account the production areas and the arhieved production for 1999, the fish production average for carp farming ponds was 632,63 kilograms per hectare. Of course, as we already highlighted this is the average, and according to the data provided, some fish farms arhieved cost-effective production, i. e. a produstion of over 1.000 kilograms per hectare. In trout farming ponds, the fish production average amounded to 133,17 tons per hectare. During 1999. 13.501,93 tons of fish food were used. Of this quantity, 12.553,13 tons were used in carp ponds and 948,81 tons in trout ponds. Naturally, corn is still most predominant food for carp species fish. As to the use of various raw materials, the overall amound used was 2.690,21 tons. Among the fixed assets for 1999, there were 218 boats, 74 outboard engines, 121 landing nets, 57 scatter guns. Among the accessories there were mats (known in colloquial Croatian terms as sak and meredov, receptacle for fish transport (tubs, pumps, devices for fish sorting

  9. Demersal Fish Monitoring Princess Amalia Wind Farm

    NARCIS (Netherlands)

    Hal, van R.

    2014-01-01

    This report describes the results of field work in the Princess Amalia Wind Farm (in Dutch: Prinses Amaliawindpark, or PAWP). The field work meets the requirements of the Monitoring and Evaluation Programme, which is part of the Wbr-permit of the wind farm. The objective is to determine if the wind

  10. Market tntegration between farmed and wild fish

    DEFF Research Database (Denmark)

    Bronnmann, Julia; Ankamah-Yeboah, Isaac; Nielsen, Max

    2016-01-01

    Following decade-long growth in worldwide farming of pangasius and tilapia, imports to Germany, a main European market, have been reduced since 2010. One reason for this might be supply growth of wild species at the total German whitefish market, if market integration exists between farmed and wild...

  11. Checklists of Parasites of Farm Fishes of Babylon Province, Iraq

    Directory of Open Access Journals (Sweden)

    Furhan T. Mhaisen

    2016-01-01

    Full Text Available Literature reviews of all references concerning the parasitic fauna of fishes in fish farms of Babylon province, middle of Iraq, showed that a total of 92 valid parasite species are so far known from the common carp (Cyprinus carpio, the grass carp (Ctenopharyngodon idella, and the silver carp (Hypophthalmichthys molitrix as well as from three freshwater fish species (Carassius auratus, Liza abu, and Heteropneustes fossilis which were found in some fish farms of the same province. The parasitic fauna included one mastigophoran, three apicomplexans, 13 ciliophorans, five myxozoans, five trematodes, 45 monogeneans, five cestodes, three nematodes, two acanthocephalans, nine arthropods, and one mollusc. The common carp was found to harbour 81 species of parasites, the grass carp 30 species, the silver carp 28 species, L. abu 13 species, C. auratus one species, and H. fossilis one species. A host-parasite list for each fish species was also provided.

  12. Coping styles in farmed fish: consequences for aquaculture

    DEFF Research Database (Denmark)

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

    2017-01-01

    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......Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is present...... in all vertebrate taxa including fish. In farmed animals, the interest in consistent trait associations, that is coping styles, has increased dramatically over the last years because many studies have demonstrated links to performance traits, health and disease susceptibility and welfare. This study...

  13. FishNet: an online database of zebrafish anatomy

    Directory of Open Access Journals (Sweden)

    Gibson Abigail J

    2007-08-01

    Full Text Available Abstract Background Over the last two decades, zebrafish have been established as a genetically versatile model system for investigating many different aspects of vertebrate developmental biology. With the credentials of zebrafish as a developmental model now well recognized, the emerging new opportunity is the wider application of zebrafish biology to aspects of human disease modelling. This rapidly increasing use of zebrafish as a model for human disease has necessarily generated interest in the anatomy of later developmental phases such as the larval, juvenile, and adult stages, during which many of the key aspects of organ morphogenesis and maturation take place. Anatomical resources and references that encompass these stages are non-existent in zebrafish and there is therefore an urgent need to understand how different organ systems and anatomical structures develop throughout the life of the fish. Results To overcome this deficit we have utilized the technique of optical projection tomography to produce three-dimensional (3D models of larval fish. In order to view and display these models we have created FishNet http://www.fishnet.org.au, an interactive reference of zebrafish anatomy spanning the range of zebrafish development from 24 h until adulthood. Conclusion FishNet contains more than 36 000 images of larval zebrafish, with more than 1 500 of these being annotated. The 3D models can be manipulated on screen or virtually sectioned. This resource represents the first complete embryo to adult atlas for any species in 3D.

  14. Diversity Patterns of Benthic Macrofauna Caused by Marine Fish Farming

    Directory of Open Access Journals (Sweden)

    Arnaldo Marín

    2011-04-01

    Full Text Available This paper reviews the patterns observed in the diversity and structure of the macrofauna benthic community under the influence of fish farming. First, we explain the effects of organic enrichment on the sediment and the consequences for the inhabiting communities. We describe the diversity trends in spatial and temporal gradients affected by fish farming and compare them with those described by the Pearson and Rosenberg model. We found that in general terms, the trends of diversity and other community parameters followed the Pearson and Rosenberg model but they can vary to some extent due to sediment local characteristics or to secondary disturbances. We also show the different mechanisms by which wild fish can affect macrofauna diversity patterns under fish farming influence. In addition, we comment the importance of the macrofauna diversity in the ecosystem functions and propose some guidelines to measure functional diversity related to relevant processes at ecosystem level. We propose more research efforts in the main topics commented in this review to improve management strategies to guarantee a good status of the diversity and ecosystem functioning of sediments influenced by fish farming.

  15. Environmental impact assessment of fish farm hatcheries ...

    African Journals Online (AJOL)

    Environmental impact assessments were taken to determine the causes of environmental threats to farm lands and the environment in the selected areas. Of significance of impact assessment were activities like air, traffic, noise, had insignificant impact (p > 0.05), while water pollution, insecurity as a result of land exposure ...

  16. Incidence of Poverty among Fish Farming Households in Oyo and ...

    African Journals Online (AJOL)

    The objective of the study is to analyse poverty among fish farming households based on functioning and capabilities in the study area. The study covered both Oyo and Osun states of Nigeria. Primary data were collected via structured questionnaire. The study employed multistage sampling technique. In all, a total of 280 ...

  17. Fish on farms combat dietary deficits in Cambodia | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2014-04-11

    Apr 11, 2014 ... “We are trying to improve the whole family's nutrition,” says Helen Keller International country director Zaman Talukder, describing the program called Fish on Farms. “But we're particularly targeting vulnerable children under five and women of childbearing age.” Those women and children face significant ...

  18. Cage fish farming in the Volta lake and the lower Volta : Practices ...

    African Journals Online (AJOL)

    Concerns have been raised about the proliferation of cage fish farming in the Volta lake and the potential water quality impacts. The study was undertaken to determine current cage fish farming practices on the lake, and to assess their impacts on water quality of the lake. Forty cage fish farm operators were interviewed for ...

  19. The dual myths of the healthy wild fish and the unhealthy farmed fish

    OpenAIRE

    Bergh, Øivind

    2007-01-01

    Although diseases, suffering and death have always been recognized as intrinsic parts of life as far as humans are concerned, it seems that many people tend to disregard these factors when it comes to animals. In particular, wild fish are generally assumed to be ‘healthy’, although the public concept of that term is unclear. In contrast, farmed fish are often popularly viewed as ‘unhealthy’. Present knowledge of the importance of epizootics among wild fish is clearly limited, especially re...

  20. Leaching of feed nutrients, economic losses to fish farming | FALAYI ...

    African Journals Online (AJOL)

    Total proteins and total lipids retention at 10, 20, 30 and 60 minutes were observed in the laboratory. There were decreasing trends ... The economic evaluation was highest (P < 0.05) in CMC in net production value, value of fish, cost of feed, gross profit, incidence of cost and the least in profit index. However, CS binder was ...

  1. Family fish farming improves quality of life in the Bolivian Amazon ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    practice fish farming, previously among the most vulnerable, now consume more fish: nearly 42 kg per year. Fish sales generate additional income of. US$15,000 a year per rural family, compared to. US$3,000 per year generated on average. For this. “ ” reason, a growing number of families are now making fish farming ...

  2. Self-perceived vision in farming, forestry, and fishing occupations.

    Science.gov (United States)

    Siegel, Miriam

    2017-01-02

    Using data from the 2005-2006 and 2007-2008 NHANES questionnaires, we evaluated self-perceived vision difficulty in individuals with a history of farming, forestry, and fishing (FFF) occupations. A self-perceived vision difficulty indicator was derived from responses to 3 separate measures. Those indicating farming, forestry, or fishing as longest job worked were classified as having an FFF history and compared to those reporting any other occupation. Logistic regression analyses utilizing NHANES sampling weights were conducted. After controlling for age, gender, race/ethnicity, education, and income-to-poverty ratio, those with an FFF history were 76% more likely to report vision difficulty than those having an alternate occupational history. Personal protective equipment and routine optometric examination may be particularly prudent for this occupational group.

  3. Coping styles in farmed fish: consequences for aquaculture

    DEFF Research Database (Denmark)

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

    2017-01-01

    Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is prese...... as well as flexible behavioural patterns are pinpointed as central themes. In addition, the ontogeny of coping styles and the influence of age, social context and environmental change in coping styles will also be discussed...

  4. Advances of FishNet towards a fully automatic monitoring system for fish migration

    Science.gov (United States)

    Kratzert, Frederik; Mader, Helmut

    2017-04-01

    Restoring the continuum of river networks, affected by anthropogenic constructions, is one of the main objectives of the Water Framework Directive. Regarding fish migration, fish passes are a widely used measure. Often the functionality of these fish passes needs to be assessed by monitoring. Over the last years, we developed a new semi-automatic monitoring system (FishCam) which allows the contact free observation of fish migration in fish passes through videos. The system consists of a detection tunnel, equipped with a camera, a motion sensor and artificial light sources, as well as a software (FishNet), which helps to analyze the video data. In its latest version, the software is capable of detecting and tracking objects in the videos as well as classifying them into "fish" and "no-fish" objects. This allows filtering out the videos containing at least one fish (approx. 5 % of all grabbed videos) and reduces the manual labor to the analysis of these videos. In this state the entire system has already been used in over 20 different fish passes across Austria for a total of over 140 months of monitoring resulting in more than 1.4 million analyzed videos. As a next step towards a fully automatic monitoring system, a key feature is the automatized classification of the detected fish into their species, which is still an unsolved task in a fully automatic monitoring environment. Recent advances in the field of machine learning, especially image classification with deep convolutional neural networks, sound promising in order to solve this problem. In this study, different approaches for the fish species classification are tested. Besides an image-only based classification approach using deep convolutional neural networks, various methods that combine the power of convolutional neural networks as image descriptors with additional features, such as the fish length and the time of appearance, are explored. To facilitate the development and testing phase of this approach

  5. Viral haemorrhagic septicaemia virus in marine fish and its implications for fish farming - a review

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig

    2005-01-01

    origin of the isolates, with one group representing traditional European freshwater isolates and isolates of north European marine origin, a second group of marine isolates from the Baltic Sea, a third group of isolates from the North Sea, and a group representing North American isolates. Examples...... of possible transfer of virus from free-living marine fish to farmed fish are discussed, as are measures to prevent introduction of VHSV from the marine environment to aquaculture....

  6. Level of Aflatoxin in Some Fish Feeds from Fish Farming Processes, Feed Factories and Imported Feeds

    OpenAIRE

    Altuğ, Gülşen

    2003-01-01

    Aflatoxins that are toxic metabolites for human and animals were determined in some fish feed. Eighty-five unit samples taken from "fish farming processes", "feed factories" and "imported feeds" in 1998, 1999 and 2000 were analyzed. In the analysis, thin layer chromatography (TLC) and enzyme linked immunosorbent assay (ELISA) technique were used. Consequently, aflatoxin levels above 20 ppb were detected in 20 samples and from 21.2 to 42.4...

  7. Influence of net-cage fish farming on zooplankton biomass in the Itá reservoir, SC, Brazil Influência da piscicultura em tanque-rede sobre a biomassa do zooplâncton no reservatório de Itá, SC, Brasil

    Directory of Open Access Journals (Sweden)

    Bruna Roque Loureiro

    2011-12-01

    Full Text Available OBJECTIVES: This study aimed to verify the influence of net-cage fish farming on zooplankton biomass in the Itá reservoir (Uruguay River, Brazil. METHODS: Samples were collected monthly from October/2009 to May/2010 at the surface and at the bottom in two sampling stations, the net-cage area and in a control area using a Van Dorn bottle and a plankton net (68 µm. RESULTS: The Cladocera and Copepoda biomass was estimated by dry weight using a micro-analytical balance, and the Rotifera biomass by Biovolume. Total zooplankton biomass varied between 6.47 and 131.56 mgDW.m-3 Calanoida copepod presented the highest value of biomass (127.56 mgDW.m-3 and rotifers, despite having an important contribution to total density, showed a maximum biomass of 2.01 mgDW.m-3. Zooplankton biomass at the net-cage area surface was higher when compared with the control area during the months of October to January. However, the zooplankton biomass was similar at the bottom of the two areas throughout the studied period. From February until May, zooplankton biomass decreased in both sampling stations, a fact probably associated with the flushing of the reservoir, followed by an increase in water transparency and a decrease in chlorophyll-a concentration in the following months (February to May. CONCLUSIONS: The influence of fish farming on zooplankton biomass was detected at the surface of the net-cage area only from October to January. From February to May this influence was not found, probably by the influence of the flushing of the reservoir.OBJETIVO: Este estudo teve o objetivo de verificar a influencia da piscicultura em tanque-rede sobre a biomassa da comunidade zooplanctônica no reservatório de Itá (Rio Uruguai, Brasil. METODOLOGIA: Foram realizadas coletas mensais de outubro/2009 a maio/2010 na superfície e no fundo em dois pontos amostrais, ponto tanque-rede e em uma área controle, com o auxílio da garrafa Van Dorn e rede de plâncton (68 µm. RESULTADOS

  8. Potential retention effect at fish farms boosts zooplankton abundance

    Science.gov (United States)

    Fernandez-Jover, D.; Toledo-Guedes, K.; Valero-Rodríguez, J. M.; Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  9. THE NEED FOR DIVERSIFICATION IN FISH FARMING PRODUCTION

    Directory of Open Access Journals (Sweden)

    Krešimir Pažur

    1999-06-01

    Full Text Available One of the characteristics of developed economies in the world is a very rich and diversified offer of goods. There are many products of different assortment, of different quality and price on the market. In keeping with the marketing conception, the production is trying to satisfy all potential consumers. Croatian freshwater fish farming has not yet reached this stage. The assortment is very limited and includes mostly carp (up to 80%, Californian trout (up to 10%, grass carp (around 4%, wels, pike-perch and pike together up to 2.70%, while the rest are commercially insignificant and uninteresting fish species. In the last few years, an increasingly important type of consumers has emerged on the market sporting anglers whose importance is growing and bringing totally new, specific demands that the fish ponds at the moment cannot meet, except maybe in marginal quantities. There is a categorical imperative of a fast adjustment of the production assortment of our fishing farms to the tendencies in the nourishment of the population in developed countries that can also be observed in our country and to the demands and needs of sporting anglers.

  10. Ecological role of bluefin tuna (Thunnus thynnus) fish farms for associated wild fish assemblages in the Mediterranean Sea.

    Science.gov (United States)

    Stagličić, Nika; Šegvić-Bubić, Tanja; Ugarković, Pero; Talijančić, Igor; Žužul, Iva; Tičina, Vjekoslav; Grubišić, Leon

    2017-12-01

    The ecological effects of tuna fish farms are largely undocumented. This study confirmed their high capacity to attract surrounding wild fish. The aggregation effect persisted year round, without detectable seasonal differences. Farm impact was restricted to close proximity of the sea cages, and was more prominent over the bottom than in the water column strata. Tuna fish farms proved to be high energy trophic resources, as indicated by the enhanced fitness status of two focal species, bogue and seabream. Under abundant food supply, seabream appear to allocate the majority of energy reserves to gonad development. Farm associated bogue had greater parasite loads, with no detrimental effect on fitness status. Overall, tuna fish farms can be regarded as population sources for aggregated wild fish, and under the no fishing conditions within the leasehold areas, can serve as functional marine protected areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Differential response of fish assemblages to coral reef-based seaweed farming.

    Directory of Open Access Journals (Sweden)

    E James Hehre

    Full Text Available As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1 marine protected areas (MPAs were established, (2 neither MPAs nor blast fishing was present (hence "unprotected", and (3 blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs.

  12. Seafood research from fish to dish : quality, safety and processing of wild and farmed fish

    NARCIS (Netherlands)

    Luten, J.B.

    2006-01-01

    In this book, scientists from various disciplines address the advances in seafood research with respect to quality, safety, consumer’s demands and processing of wild and farmed fish. The nutritional properties of marine lipids and lipid oxidation from model systems to seafood are presented. Several

  13. Reuse of polyethylene fibres from discarded fishing nets as reinforcement in gypsym-based materials

    DEFF Research Database (Denmark)

    Bertelsen, Ida Maria Gieysztor; Ottosen, Lisbeth M.

    In this study, the potential of reusing plastic fibres from discarded waste fishing nets of polyethylene (PE) as fibre reinforcement in gypsum-based building materials is investigated. The fishing nets were not reprocessed, but simply washed and cut to monofilament fibres by an industrial operation...

  14. DNA vaccines against viral diseases of farmed fish.

    Science.gov (United States)

    Evensen, Øystein; Leong, Jo-Ann C

    2013-12-01

    Immunization by an antigen-encoding DNA was approved for commercial sale in Canada against a Novirhabdovirus infection in fish. DNA vaccines have been particularly successful against the Novirhabdoviruses while there are reports on the efficacy against viral pathogens like infectious pancreatic necrosis virus, infectious salmon anemia virus, and lymphocystis disease virus and these are inferior to what has been attained for the novirhabdoviruses. Most recently, DNA vaccination of Penaeus monodon against white spot syndrome virus was reported. Research efforts are now focused on the development of more effective vectors for DNA vaccines, improvement of vaccine efficacy against various viral diseases of fish for which there is currently no vaccines available and provision of co-expression of viral antigen and immunomodulatory compounds. Scientists are also in the process of developing new delivery methods. While a DNA vaccine has been approved for commercial use in farmed salmon in Canada, it is foreseen that it is still a long way to go before a DNA vaccine is approved for use in farmed fish in Europe. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. A COMPARATIVE DESCRIPTION OF THE ECOLOGICAL STATE OF NURSERY PONDS OF THE LVIV FISH FARM

    Directory of Open Access Journals (Sweden)

    A. Dobrjanska

    2014-06-01

    Full Text Available Purpose. Study of the ecological state of aquaculture ponds of the Lviv fish farms “Rudnyky” and “Derzhiv” for creation of optimum conditions for fish growing in ponds. Methodology. Growing of fish in the fish farm “Rudnyky” were conducted in the summer brood fish pond №12 of 4.2 ha area. The pond was stocked with yearlings of Lubin scaled and framed carps with an average weight of 83.3 g and stocking density of 1428 fish/ha. In the fish farm “Derzhiv”, growing of fish was conducted in the pond №1 of 4.2 ha area. The pond was stocked with fish larvae with stocking density of 18000 fish/ha. Determination of hydrochemical parameters was conducted using generally accepted analytical chemical methods. Quantitative determination of heavy metal content in water and bottom sediments was conducted by direct absorption in propane-butane flame with the aid of the absorption spectrophotometer C-115 M1. Findings. As a result of the conducted studies, we determined the pollution level of aquaculture ponds in the Lviv fish farms. Main hydrochemical indices, which characterize quality of water pond, meet norms for fish farming. All studied heavy metals in pond water of “Rudnyky” fish farm were at higher concentrations compared to those in the fish farm “Derzhiv”. Bottom sediments are characterized by a tendency of increasing nickel concentrations in both examined fish farms, values of which exceeded the maximum acceptable concentration. In the order of an increase of heavy metal content in bottom sediments, they can be ranged as Fe-Mn-Zn-Cd-Pb-Co-Cu-Ni. Originality. The ecological state of aquaculture ponds of the Lviv fish farms “Rudnyky” and “Derzhiv” has been investigated for the first time. Practical value. The obtained results of the ecological state of aquaculture ponds allow creating optimum conditions for growing of fish.

  16. Dynamic Analysis of Feed Pipes for Fish Farming in Open Sea

    OpenAIRE

    Gjuka, Asdren

    2017-01-01

    Master's thesis in Offshore technology: Marine and subsea technology The demand for seafood is continuously growing throughout the world, while the number of sheltered locations for fish farming is decreasing. Consequently, the industry is pushed to fin nd new and innovative solutions to this problem. One solution is to move the fish farms in non-sheltered locations, which requires extensive research on all structural parts of a fish farm, including components of the feeding system. The ma...

  17. First isolation of an aquatic birnavirus from farmed and wild fish species in Australia.

    Science.gov (United States)

    Crane, M S; Hardy-Smith, P; Williams, L M; Hyatt, A D; Eaton, L M; Gould, A; Handlinger, J; Kattenbelt, J; Gudkovs, N

    2000-10-25

    During routine sampling and testing, as part of a systematic surveillance program (the Tasmanian Salmonid Health Surveillance Program), an aquatic birnavirus was isolated from 'pin-head' (fish exhibiting deficient acclimatisation on transfer to saltwater) Atlantic salmon Salmo salar, approximately 18 mo old, farmed in net-pens located in Macquarie Harbour on the west coast of Tasmania, Australia. The isolate grows readily in a range of fish cell lines including CHSE-214, RTG-2 and BF-2 and is neutralised by a pan-specific rabbit antiserum raised against infectious pancreatic necrosis virus (IPNV) Ab strain and by a commercial pan-specific IPNV-neutralising monoclonal antibody. Presence of the virus was not associated with gross clinical signs. Histopathological examination revealed a range of lesions particularly in pancreatic tissue. The virus was localised in pancreas sections by immunoperoxidase staining using the polyclonal antiserum and by electron microscopy. Examination by electron microscopy demonstrated that the virus isolated in cell culture (1) belongs to the family Birnaviridae, genus Aquabirnaviridae; (2) was ultrastructurally and antigenically similar to virus identified in the index fish; (3) is related to IPNV. Western blot analysis using the polyclonal rabbit antiserum confirmed the cross-reactions between various aquatic birnavirus isolates. In addition, PCR analysis of isolated viral nucleic acid from the index case indicated that the virus is more closely related to IPNV fr21 and N1 isolates than to other birnavirus isolates available for comparison. Sampling of other fish species within Macquarie Harbour has demonstrated that the virus is present in several other species of fish including farmed rainbow trout Oncorhynchus mykiss, wild flounder Rhombosolea tapirina, cod Pseudophycis sp., spiked dogfish Squalus megalops and ling Genypterus blacodes.

  18. Fish fauna associated with floating objects sampled by experimental and commercial purse nets

    Directory of Open Access Journals (Sweden)

    Enric Massutí

    1999-12-01

    Full Text Available Based on the commercial surrounding nets traditionally used in the Coryphaena hippurus fishery, we designed an experimental purse seine (64 m long and 14 m high, with a purse line and a central codend of 2 mm mesh for sampling fish fauna associated with flotsam. Taxa, number, biomass and sizes of fishes caught with both types of gear around fish aggregation devices were compared. From 63 hauls with the experimental net, we caught 11370 fishes belonging to 17 families and 26 species. In contrast, 816 fishes belonging to 7 species and 5 families were collected from 39 commercial hauls. Despite differences in number of hauls for each net, the curves of cumulative species richness showed that additional hauls could not increase the number of species collected with the commercial net. The most abundant species from experimental net catches were Trachurus picturatus, which represented over 80% of the specimens caught in spring and summer, Naucrates ductor, which represented about 50% of autumn catches, both in terms of abundance and biomass, and Seriola dumerili, which represented 46% and 21% of the samples taken in summer and autumn respectively. Seriola dumerili was also frequent in commercial net catches, in which T. picturatus did not appear, while Coryphaena hippurus and N. ductor represented more than 85% of both abundance and biomass. Large differences between the two types of net were also obtained in the mean fish weight and length frequency distributions of the catches by season. Fish caught with the experimental net ranged from 6 to 570 mm length, while fish collected from commercial hauls had a size range of 35 to 700 mm. The effectiveness of the experimental net in catching small fishes showed that it can be an optimal sampling method not only in the study of fish fauna associated with flotsam, but also in studies to catch early life stages.

  19. Development and short-term dynamics of macrofouling assemblages on fish-cage nettings in a tropical estuary

    Science.gov (United States)

    Madin, John; Chong, V. C.; Basri, Badrulnizam

    2009-06-01

    A study was conducted at a fish culture farm in the Jaha River estuary, Malaysia, to examine the structure and development of macrofouling assemblages on floating net-cages. The study was conducted during the dry (August-October 2001) and wet (December-February 2002) seasons. Biofouling on 1.6 cm mesh net panels (size 0.2 m × 2 m) suspended inside (P, T) and outside (O) experimental net-cages was monitored every week until net openings were completely occluded by macrofouling organisms (8 wk and 12 wk for dry and wet seasons respectively). Seven species (6 phyla) of sessile organisms and 23 species (3 phyla) of non-sessile associates were recorded. Macro-colonization of net panels began with the hydroid Plumularia sp. irrespective of season and treatment (P, T, and O), while other species only appeared after 1 or 2 weeks of immersion. Inside net-cages where water flow was slow (mean colonization, and depth distribution of the macrofouling organisms.

  20. Contaminants in popular farmed fish consumed in The Netherlands and their levels in fish feedContaminants in popular farmed fish consumed in The Netherlands and their levels in fish feed

    NARCIS (Netherlands)

    Leeuwen, van S.; Velzen, van M.; Swart, K.; Veen, van der I.; Traag, W.A.; Spanjer, M.; Scholten, J.; Rijn, van H.

    2008-01-01

    Investigated is a wide range of pollutants in the top five consumed fish in the Netherlands (salmon, trout, tilapia, pangasius and shrimps). Farmed fish samples were collected from different sources (supermarkets, fish stores, markets and suppliers for restaurants) and analysed for PCDD/Fs, PCBs,

  1. The influence of pearl oyster farming on reef fish abundance and diversity in Ahe, French Polynesia.

    Science.gov (United States)

    Cartier, Laurent E; Carpenter, Kent E

    2014-01-15

    Many cultured pearl farms are located in areas of the Pacific that have thriving, highly diverse fish communities but the impacts of farming on these communities are poorly understood. We studied the effects of pearl oyster farming on shore fish abundance and diversity in the lagoon of Ahe, French Polynesia by adapting roving diver census methods to the coral reef bommies of the lagoon and compared 16 sites with high pearl farming impact to others with no direct impact. Pearl farming has a slightly positive effect on reef fish abundance (N) and no significant impact on fish diversity (H) or community composition. This is important when considering the ecological sustainability of pearl farming in French Polynesia and suggests that a potential synergy between pearl farms and marine conservation should be further explored. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Environmental impacts of coastal fish farming; Carbon and Nitrogen budgets for trout farming in Kaldbacksfjord, Faroe Islands

    DEFF Research Database (Denmark)

    Nordi, Gunnvor A; Glud, Ronnie N.; Gaard, Eilif

    2011-01-01

    Flow of organic carbon (OC) and nitrogen through a sea cage trout farm was calculated on the basis of detailed studies of the farming operation, water circulation, OC and nutrient transport and recycling processes in sediment. A third of the OC and nitrogen provided by fish food was incorporated...... into fish biomass, which is more than has been found in previous studies. Most OC input was respired by the fish (52 to 70%), and similar to 63% of the associated nitrogen was lost as dissolved inorganic nitrogen (DIN), potentially stimulating pelagic primary production. Approx. 6% of carbon and 5......% of nitrogen derived from fish food settled on the seabed, where it was either mineralized or accumulated in the sediment. Based on transect measurements of diagenetic activity, the farm footprint was found to cover an area similar to 10 times the farm area. OC mineralization in the sediment increased linearly...

  3. Parasites infestation on juvenile tiger grouper (Epinephelus fuscoguttatus nursed in net cage at Sea Farming Instalation Kepulauan Seribu, Jakarta

    Directory of Open Access Journals (Sweden)

    Yani Hadiroseyani

    2010-07-01

    Full Text Available This study was aimed to identify fauna parasite of juvenile tiger grouper (Epinephelus fuscoguttatus on the two locations of floating net at Floating Net Sea Farming Center, Pulau Seribu Jakarta. A total of five tiger grouper fry from each location, checked every two weeks during the nursery period in August-September 2008 and June-August 2009. Parasites of young tiger grouper found were protozoa (Trichodina and myxosporea, monogenea Diplectanum, metaserkaria digenea, and isopods Alitropus. Diplectanum infestation was dominant with prevalence reached 100% and the average intensity of 2,87-72,8. Fish nursed in the Perairan Pulau Semak Daun was more susceptible compared to the fish nursed in Pulau Karang Congkak. Keywords: tiger grouper, parasite, infestation, Seribu Island. ABSTRAKPenelitian ini bertujuan untuk mengidentifikasi penyakit yang menyerang benih kerapu macan pada masa pendederan dalam karamba jaring apung di dua lokasi Karamba Jaring Apung Balai Sea Farming, Kepulauan Seribu, yaitu di Perairan Pulau Semak Daun dan Perairan Pulau Karang Congkak. Sebanyak 5 ekor benih kerapu macan dari masing-masing lokasi, diperiksa setiap minggu selama dua periode pendederan pada bulan Agustus-September 2008 dan bulan Juni-Agustus 2009. Fauna parasit benih kerapu macan pada masa pendederan dalam jaring apung tersebut meliputi protozoa (Trichodina dan myxosporea, monogenea Diplectanum, metaserkaria digenea, dan isopoda Alitropus. Diplectanum merupakan parasit yang mendominasi dengan prevalensi mencapai 100% dan intensitas rerata 2.87–72,8. Pada Perairan Pulau Semak Daun lebih banyak ditemukan jenis parasit dengan prevalensi dan intensitas yang cukup tinggi dibandingkan dengan Perairan Pulau Karang Congkak.Kata kunci: ikan kerapu macan, parasit, infestasi, Pulau Seribu.

  4. Effect of fish farming on the water quality of rivers in northeast Spain.

    Science.gov (United States)

    Ruiz-Zarzuela, I; Halaihel, N; Balcázar, J L; Ortega, C; Vendrell, D; Pérez, T; Alonso, J L; de Blas, I

    2009-01-01

    The effects of fish farming activities on the aquatic environment were evaluated by studying the water quality of twelve rivers located in northeast Spain. Two sampling sites were used for each river: the first sampling point was located just upstream from the fish farming facilities and the second one was downstream from fish farm effluent discharge point. In order to avoid any misinterpretation due to watershed location and seasonality, a stratified statistical analysis was performed. The results show significant decreases in pH and dissolved oxygen, in contrast to chemical oxygen demand, ammonia, phosphates and microbiological parameters, which significantly increased downstream from the fish farm discharges. Other significant variations were also found for conductivity and temperature. According to the European and local regulations concerning to support fish populations, our results fell within the allowable limits for salmonid waters. Nevertheless, we suggest that further investigations should be carried out to study the ecological interactions between farmed and wild fish populations.

  5. Association of health involvement and attitudes towards eating fish on farmed and wild fish consumption in Belgium, Norway and Spain

    NARCIS (Netherlands)

    Altintzoglou, T.; Vanhonacker, F.; Verbeke, W.; Luten, J.B.

    2011-01-01

    Consumers in many European countries do not equally meet the recommended daily intake levels for fish consumption. Various factors that can influence fish consumption behaviour have been identified but limited research has been performed on fish consumption behaviour, discriminating between farmed

  6. Factors affecting farmers' adoption of integrated rice-fish farming systems in the Mekong delta, Vietnam

    NARCIS (Netherlands)

    Bosma, R.H.; Nhan, D.K.; Udo, H.M.J.; Kaymak, U.

    2012-01-01

    This study investigated the determinants of the adoption of improved rice–fish farming systems in the Mekong delta to support policy making, agricultural land-use planning and extension of integrated rice–fish farming. Recently these systems have been referred to as adaptations to climate change,

  7. Semi-continuously addition of peracetic acid to a flow-through fish farm

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Henriksen, Niels Henrik

    2017-01-01

    •Demonstration of a safe and reliable practical method to reduce ectoparasites related mortality of farmed fish.•Central peracetic acid application caused even distribution to all ponds and considered suitable for organic fish farming.•Low dose and easy degradable peracetic acid is an alternative...... aquaculture management approach to formalin flush treatment....

  8. Automatic fishing net detection and recognition based on optical gated viewing for underwater obstacle avoidance

    Science.gov (United States)

    Liu, Xiaoquan; Wang, Xinwei; Ren, Pengdao; Cao, Yinan; Zhou, Yan; Liu, Yuliang

    2017-08-01

    An automatic fishing net detection and recognition method for underwater obstacle avoidance is proposed. In the method, optical gated viewing technology is utilized to obtain high-resolution fishing net images and extend detection distance by suppressing water backscattering and background noise. The fishing net recognition is based on the proposed histograms of slope lines (HSLs) descriptors plus a support vector machine classifier. The extraction of HSL descriptors includes five steps of contrast-limited adaptive histogram equalization, the Gaussian low-pass filtering, the Canny detection, the Hough transform, and weighted vote. In the proof experiments, the detection distance of the fishing net reaches 5.7 attenuation length and the recognition accuracy reaches 93.79%.

  9. Influence of throat configuration and fish density on escapement of channel catfish from hoop nets

    Science.gov (United States)

    Porath, Mark T.; Pape, Larry D.; Richters, Lindsey K.

    2011-01-01

    In recent years, several state agencies have adopted the use of baited, tandemset hoop nets to assess lentic channel catfish Ictalurus punctatus populations. Some level of escapement from the net is expected because an opening exists in each throat of the net, although factors influencing rates of escapement from hoop nets have not been quantified. We conducted experiments to quantify rates of escapement and to determine the influence of throat configuration and fish density within the net on escapement rates. An initial experiment to determine the rate of escapement from each net compartment utilized individually tagged channel catfish placed within the entrance (between the two throats) and cod (within the second throat) compartments of a single hoop net for overnight sets. From this experiment, the mean rate (±SE) of channel catfish escaping was 4.2% (±1.5) from the cod (cod throat was additionally restricted from the traditionally manufactured product), and 74% (±4.2) from the entrance compartments. In a subsequent experiment, channel catfish were placed only in the cod compartment with different throat configurations (restricted or unrestricted) and at two densities (low [6 fish per net] and high [60 fish per net]) for overnight sets to determine the influence of fish density and throat configuration on escapement rates. Escapement rates between throat configurations were doubled at low fish density (13.3 ± 5.4% restricted versus 26.7 ± 5.6% unrestricted) and tripled at high fish density (14.3 ± 4.9% restricted versus 51.9 ± 5.0% unrestricted). These results suggest that retention efficiency is high from cod compartments with restricted throat entrances. However, managers and researchers need to be aware that modification to the cod throats (restrictions) is needed for hoop nets ordered from manufacturers. Managers need to be consistent in their use and reporting of cod end throat configurations when using this gear.

  10. Artisanal fishing net float loss and a proposal for a float design solution

    Directory of Open Access Journals (Sweden)

    Paulo de Tarso Chaves

    2016-03-01

    Full Text Available Abstract Plastic floats from fishing nets are commonly found washed up on beaches in southern Brazil. They are usually broken and show signs of having been repaired. Characteristics of floats and interviews with fishermen suggest two main causes of float loss. First, collisions between active gear, bottom trawl nets for shrimp, and passive gear, drift nets for fish, destroy nets and release fragments of them, including floats. Second, the difficulty with which floats are inserted on the float rope of the nets when they are used near the surface. Floats are inserted to replace damaged or lost floats, or they may be removed if it is desired that the nets be used in deeper waters. Floats may thus be poorly fixed to the cables and lost. Here a new float design that offers greater safety in use and for the replacement of floats is described and tested.

  11. Environmental health impacts of feeding crops to farmed fish.

    Science.gov (United States)

    Fry, Jillian P; Love, David C; MacDonald, Graham K; West, Paul C; Engstrom, Peder M; Nachman, Keeve E; Lawrence, Robert S

    2016-05-01

    Half of the seafood consumed globally now comes from aquaculture, or farmed seafood. Aquaculture therefore plays an increasingly important role in the global food system, the environment, and human health. Traditionally, aquaculture feed has contained high levels of wild fish, which is unsustainable for ocean ecosystems as demand grows. The aquaculture industry is shifting to crop-based feed ingredients, such as soy, to replace wild fish as a feed source and allow for continued industry growth. This shift fundamentally links seafood production to terrestrial agriculture, and multidisciplinary research is needed to understand the ecological and environmental health implications. We provide basic estimates of the agricultural resource use associated with producing the top five crops used in commercial aquaculture feed. Aquaculture's environmental footprint may now include nutrient and pesticide runoff from industrial crop production, and depending on where and how feed crops are produced, could be indirectly linked to associated negative health outcomes. We summarize key environmental health research on health effects associated with exposure to air, water, and soil contaminated by industrial crop production. Our review also finds that changes in the nutritional content of farmed seafood products due to altered feed composition could impact human nutrition. Based on our literature reviews and estimates of resource use, we present a conceptual framework describing the potential links between increasing use of crop-based ingredients in aquaculture and human health. Additional data and geographic sourcing information for crop-based ingredients are needed to fully assess the environmental health implications of this trend. This is especially critical in the context of a food system that is using both aquatic and terrestrial resources at unsustainable rates. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Effect of twine diameter on fishing power of experimental gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    The relative fishing powers of experimental gill nets were estimated for shorthorn sculpin (Myoxocephalus scorpius), Greenland cod (Gadus ogac), and Atlantic cod (Gadus morhua). The results suggested that fishing power was negatively correlated to the ratio between twine diameter and mesh size...

  13. Farm-level risk factors for fish-borne zoonotic trematode infection in integrated small-scale fish farms in northern Vietnam.

    Directory of Open Access Journals (Sweden)

    Van Thi Phan

    Full Text Available BACKGROUND: Northern Vietnam is an endemic region for fish-borne zoonotic trematodes (FZT, including liver and intestinal flukes. Humans acquire the FZT infection by eating raw or inadequately cooked fish. The production of FZT-free fish in aquaculture is a key component in establishing a sustainable program to prevent and control the FZT transmission to humans. Interventions in aquaculture should be based on knowledge of the main risk factors associated with FZT transmission. METHODOLOGY/PRINCIPAL FINDINGS: A longitudinal study was carried out from June 2006 to May 2007 in Nam Dinh province, Red River Delta to investigate the development and risk factors of FZT infections in freshwater cultured fish. A total of 3820 fish were sampled six times at two-month intervals from 96 fish farms. Logistic analysis with repeated measurements was used to evaluate potential risk factors based on information collected through questionnaire interviews with 61 fish farm owners. The results showed that the FZT infections significantly increased from first sampling in June to July 2006 (65% to sixth sampling in April to May, 2007 (76%. The liver fluke, Clonorchis sinensis and different zoonotic intestinal flukes including Haplochis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus and Procerovum varium were found in sampled fish. Duration of fish cultured (sampling times, mebendazole drug self-medication of household members, presence of snails in the pond, and feeding fish with green vegetation collected outside fish farms all had a significant effect on the development of FZT prevalence in the fish. CONCLUSIONS/SIGNIFICANCE: The FZT prevalence in fish increased by 11 percentage points during a one-year culture period and the risk factors for the development of infection were identified. Results also highlight that the young fish are already highly infected when stocked into the grow-out systems. This knowledge should be incorporated into control

  14. Human and veterinary pharmaceuticals in the marine environment including fish farms in Korea.

    Science.gov (United States)

    Kim, Hee-Young; Lee, In-Seok; Oh, Jeong-Eun

    2017-02-01

    The occurrence trends and effects of 30 human and veterinary pharmaceuticals, including antibiotics, anthelmintics, anti-inflammatory drugs, and β-blockers, in the marine environment, with a focus on seawater, sediment, cultured fish, and their feed collected from coastal and fish farm areas in the southern sea of Korea, were investigated. The concentrations of total pharmaceuticals in coastal area seawater (mean: 533ng/L) were higher than those in fish farm seawater (mean: 300ng/L), while the opposite trend (coastal area: 136ng/gdrywtpharmaceuticals in fish muscle (mean: 5.08ng/gwetwt) was lower than that in organs (mean: 14.1ng/gwetwt). However, not all compounds were present at higher concentrations in organs. Characteristic distribution patterns of pharmaceuticals were observed according to sample types and sampling sites based on the predominance of various antibiotics in fish farms (including cultured fish and feed) and the predominance of pharmaceuticals of terrestrial origin (human and livestock) in coastal areas. Pharmaceuticals used as fish drugs, such as sulfadiazine, erythromycin, and trimethoprim, were commonly detected in fish farm media (seawater, sediment, and cultured fish), which might contaminate fish farm media. Copyright © 2016. Published by Elsevier B.V.

  15. Sources and fate of antimicrobials in integrated fish-pig and non-integrated tilapia farms.

    Science.gov (United States)

    Li, Kang; Liu, Liping; Zhan, Jia; Scippo, Marie-Louise; Hvidtfeldt, Kristian; Liu, Yuan; Dalsgaard, Anders

    2017-10-01

    Antimicrobial contamination in aquaculture products constitutes a food safety hazard, but little is known about the introduction and accumulation of antimicrobials in integrated fish-pig aquaculture. This study, conducted in 2013, aimed to determine the residues of 11 types of antimicrobials by UPLC-MS/MS analysis in fish feed (n=37), pig feed (n=9), pig manure (n=9), pond sediment (n=20), fish skin (n=20) and muscle tissue (n=20) sampled from integrated tilapia-pig farms, non-integrated tilapia farms and fish feed supply shops. There was a higher occurrence of antimicrobial residues in fish skin from both integrated and non-integrated farms, and in pig manure. Enrofloxacin (3.9-129.3μg/kg) and sulfadiazine (0.7-7.8μg/kg) were commonly detected in fish skin and muscle, pig manure and pond sediment from integrated farms, with different types of antimicrobials found in pig manure and tilapia samples. In non-integrated farms, sulfadiazine (2.5-89.9μg/kg) was the predominant antimicrobial detected in fish skin and muscle, fish feed and pond sediment. In general, antimicrobials seemed not to be commonly transmitted from pig to fish in tilapia-pig integrated farms, and fish feed, pig feed and pond sediment did not seem as important sources of the antimicrobials found in fish from both systems. The frequent findings of antimicrobial residues in fish skin compared with fish muscle was probably due to different pharmacokinetics in different tissue types, which have practical food safety implications since antimicrobial residues monitoring is usually performed analyzing mixed skin and fish muscle samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Hydroacoustic registration of fish abundance of offshore wind farms. Horns Rev offshore wind farm. Annual report 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Hvidt, C.B.; Bruenner, L.; Reier Knudsen, F.

    2005-05-15

    Elsam Engineering AS has approved the implementation of a project concerning the registration of fish communities in Horns Rev Offshore Wind Farm with use of hydroacoustic methods. In a joint effort, Bio/consult as, Carl Bro as and SIMRAD AS have monitored the fish communities at Horns Rev Offshore Wind Farm using a new hydroacoustic methodology. The new hydroacoustic technique combines the use of scientific sonar acoustics with GPS to determine the density, diversity and location of fish. The objectives of this project were to test the possibility of using hydroacoustic techniques as alternative methods to traditional techniques to assess the fish assemblage inhabiting offshore wind farms and to investigate the possible effect from the wind farm and hard bottom substrates (turbine foundations) on fish abundance. The field study was carried out October 9-10, 2004 and consisted of four horizontal hydroacoustic survey transects each covering impact and reference areas. Transects were surveyed in order to achieve identical impact and reference transect pairs concerning environment, topography and time correspondence. The hydroacoustic equipment consisted of a SIMRAD EK60/EY60 echo sounder with a split-beam transducer (Simrad ES 120-4x10) mounted on a pan and tilt unit, a transceiver, a laptop extended with a GPS-receiver and additional large external hard discs. The raw data files from EK60 were converted to echogram files suitable for the post processing application, Sonar5-Pro. The Sonar5-Pro software makes it possible to filter out echo detections from the surface and the bottom, as well as perform cross filter detection. The validity of the results using the hydroacoustic method is high due to the cross filtering and single target tracking technique. From the hydroacoustic results, no or very little effect from the wind farm or from hard bottom substrates was found on the fish densities at Horns Rev Wind Farm at the time of the survey. The execution of the field

  17. Mercury in UK imported fish and shellfish and UK-farmed fish and their products.

    Science.gov (United States)

    Knowles, T G; Farrington, D; Kestin, S C

    2003-09-01

    Total mercury concentrations were measured in fish and shellfish and their products imported into the UK and also in UK-produced farmed salmon and trout. Three hundred and thirty-six samples were collected using a two-stage sampling plan. The sample plan was weighted to reflect consumption, but with some bias towards fish that might accumulate higher levels of mercury, such as large predatory fish at the top of the food chain. The highest levels of total mercury were found in billfish (swordfish and marlin) and shark. Mercury concentrations in the five samples of fresh/frozen shark ranged from 1.006 to 2.200 mg kg(-1), all above the European Commission limit for the species, and concentrations in 20 samples of fresh/frozen billfish ranged from 0.153 to 2.706 mg kg(-1) with 13 samples above the 1.0 mg kg(-1) limit for the species. One sample of Antarctic ice fish was collected and had a mercury concentration of 0.664 mg kg(-1). The limit for this species was 0.5 mg kg(-1). One sample of fresh/frozen tuna out of the 20 collected had a mercury concentration above the limit of 1.0 mg kg(-1) (1.5 mg kg(-1)), but all other fresh tuna samples were well within the regulatory limit (average 0.4 mg kg(-1)). Mercury concentrations in canned tuna were lower with concentrations on average half that measured in fresh/frozen tuna. Mercury concentrations in UK-farmed salmon and trout were relatively low. The maximum concentration found in 46 samples of fresh/frozen or smoked trout and salmon was 0.103 mg kg(-1).

  18. Phage Therapy and Photodynamic Therapy: Low Environmental Impact Approaches to Inactivate Microorganisms in Fish Farming Plants

    Directory of Open Access Journals (Sweden)

    Maria A.F. Faustino

    2009-06-01

    Full Text Available Owing to the increasing importance of aquaculture to compensate for the progressive worldwide reduction of natural fish and to the fact that several fish farming plants often suffer from heavy financial losses due to the development of infections caused by microbial pathogens, including multidrug resistant bacteria, more environmentally-friendly strategies to control fish infections are urgently needed to make the aquaculture industry more sustainable. The aim of this review is to briefly present the typical fish farming diseases and their threats and discuss the present state of chemotherapy to inactivate microorganisms in fish farming plants as well as to examine the new environmentally friendly approaches to control fish infection namely phage therapy and photodynamic antimicrobial therapy.

  19. Aggregation of European storm-petrel (Hydrobates pelagicus ssp. melitensis) around cage fish farms. Do they benefit from the farmś resources?

    Science.gov (United States)

    Aguado-Giménez, F; Sallent-Sánchez, A; Eguía-Martínez, S; Martínez-Ródenas, J; Hernández-Llorente, M D; Palanca-Maresca, C; Molina-Pardo, J L; López-Pastor, B; García-Castellanos, F A; Ballester-Moltó, M; Ballesteros-Pelegrín, G; García-García, B; Barberá, G G

    2016-12-01

    Cage aquaculture aggregates wild fauna due to food provision. Several seabirds frequent fish farms, including the European storm-petrel (Hydrobates pelagicus melitensis). This work investigates the presence of storm-petrels around two aquaculture areas interspersed between breeding colonies in western Mediterranean Sea. Contribution of aquaculture-derived resources to their diet was assessed. Storm-petrels were mist-netted at the colonies and marked by bleaching feathers. Density around aquaculture areas was estimated through visual counts. Marks recognition was conducted visually and by photo-capture. Storm-petrel regurgitates were used as target tissue to estimate diet sources contribution. Contribution of surface zooplankton, ichthyoplankton and aquaculture wastes was estimated through Bayesian mixing modelling combining carbon and nitrogen stable isotopes and fatty acids as biomarkers. Storm-petrel density was high in open-sea aquaculture area, but not observed around near shore farms. Temporal variability of storm-petrels density during the breeding season was linked to their reproductive phenology. Within the open-sea aquaculture area, bluefin tuna farm was more attractive for storm-petrels than seabream/seabass farms. Visual identification of bleaching marks was not useful. Photo-capture showed that 8.3% of the storm-petrels watched around farms were firstly trapped in some of the nearby colonies, and 91.7% were unmarked. Qualitative evidence of aquaculture-derived wastes utilization was obtained. However, its estimated contribution was low (4.3%) when compared to ichthyoplankton (61.1%) or zooplankton (34.6%). The studied open-sea farms significantly aggregated storm-petrels along their entire breeding season. Storm-petrels got a slight profit from aquaculture resources. Nevertheless, some concerns arise regarding the cost/benefit balance of the interaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. An opinion paper: emphasis on white muscle development and growth to improve farmed fish flesh quality

    OpenAIRE

    Videler, J.J.

    2011-01-01

    Due to rapid depletion of wild stocks, the necessity to cultivate fish is eminent. Current fish farming practices seek to improve flesh quality. The notion that white muscles are the main target of the fishing industry is emphasized. A novel approach is suggested based on the development of white muscles in wild fish from eggs to adults. A compilation of facts about white muscle structure, function and ontogeny is followed by an account of the changes in swimming behaviour and performance rel...

  1. Growth of Tetraselmis suecica in a tubular photobioreactor on wastewater from a fish farm

    NARCIS (Netherlands)

    Michels, M.H.A.; Vaskoska, R.S.; Vermuë, M.H.; Wijffels, R.H.

    2014-01-01

    This study shows the feasibility of an integrated multi-trophic aquaculture approach where wastewater from the fish farms is used to produce feed for juvenile shellfish at high productivity and constant quality.

  2. The ICLARM-CLSU integrated animal-fish farming project: final report

    National Research Council Canada - National Science Library

    Hopkins, K.D; Cruz, E.M

    1982-01-01

    The International Center for Living Aquatic Resources Management and Central Luzon State University Integrated Animal-Fish Farming Project spanned four years, 1978 to 1981 at Nueva Ecija, Philippines...

  3. A meta-analysis approach to the effects of fish farming on soft bottom polychaeta assemblages in temperate regions

    OpenAIRE

    Martinez-Garcia, Elena; Sanchez-Jerez, Pablo; Aguado Giménez, Felipe; Ávila, Pablo; Guerrero, Alejandro; Sánchez-Lizaso, José Luis; Fernandez-Gonzalez, Victoria; González, Nieves; Gairin Deulofeu, Joan Ignasi; Carballeira, Carlos; García García, Benjamín; Carreras, Jordi; Macías, José Carlos; Carballeira, Alejo; Collado, Cayetano

    2013-01-01

    Marine fish farms could cause environmental disturbances on the sediment due to uneaten food and fish faeces that impact the marine benthos. Polychaete assemblages are considered good indicators of environmental perturbations. The present study aimed to establish groups of polychaetes as potential indicators of fish farm pollution. This study was carried out in ten fish farms along the Spanish coast. Changes in polychaete assemblage were analyzed with meta-analysis and multivariate techniques...

  4. Proxy measures of fitness suggest coastal fish farms can act as population sources and not ecological traps for wild gadoid fish.

    Science.gov (United States)

    Dempster, Tim; Sanchez-Jerez, Pablo; Fernandez-Jover, Damian; Bayle-Sempere, Just; Nilsen, Rune; Bjørn, Pal-Arne; Uglem, Ingebrigt

    2011-01-17

    Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to wild fish. To investigate if coastal salmon farms act as ecological traps for wild Atlantic cod (Gadus morhua) and saithe (Pollachius virens), we compared proxy measures of fitness between farm-associated fish and control fish caught distant from farms in nine locations throughout coastal Norway, the largest coastal fish farming industry in the world. Farms modified wild fish diets in both quality and quantity, thereby providing farm-associated wild fish with a strong trophic subsidy. This translated to greater somatic (saithe: 1.06-1.12 times; cod: 1.06-1.11 times) and liver condition indices (saithe: 1.4-1.8 times; cod: 2.0-2.8 times) than control fish caught distant from farms. Parasite loads of farm-associated wild fish were modified from control fish, with increased external and decreased internal parasites, however the strong effect of the trophic subsidy overrode any effects of altered loads upon condition. Proxy measures of fitness provided no evidence that salmon farms function as ecological traps for wild fish. We suggest fish farms may act as population sources for wild fish, provided they are protected from fishing while resident at farms to allow their increased condition to manifest as greater reproductive output.

  5. Proxy measures of fitness suggest coastal fish farms can act as population sources and not ecological traps for wild gadoid fish.

    Directory of Open Access Journals (Sweden)

    Tim Dempster

    Full Text Available BACKGROUND: Ecological traps form when artificial structures are added to natural habitats and induce mismatches between habitat preferences and fitness consequences. Their existence in terrestrial systems has been documented, yet little evidence suggests they occur in marine environments. Coastal fish farms are widespread artificial structures in coastal ecosystems and are highly attractive to wild fish. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if coastal salmon farms act as ecological traps for wild Atlantic cod (Gadus morhua and saithe (Pollachius virens, we compared proxy measures of fitness between farm-associated fish and control fish caught distant from farms in nine locations throughout coastal Norway, the largest coastal fish farming industry in the world. Farms modified wild fish diets in both quality and quantity, thereby providing farm-associated wild fish with a strong trophic subsidy. This translated to greater somatic (saithe: 1.06-1.12 times; cod: 1.06-1.11 times and liver condition indices (saithe: 1.4-1.8 times; cod: 2.0-2.8 times than control fish caught distant from farms. Parasite loads of farm-associated wild fish were modified from control fish, with increased external and decreased internal parasites, however the strong effect of the trophic subsidy overrode any effects of altered loads upon condition. CONCLUSIONS AND SIGNIFICANCE: Proxy measures of fitness provided no evidence that salmon farms function as ecological traps for wild fish. We suggest fish farms may act as population sources for wild fish, provided they are protected from fishing while resident at farms to allow their increased condition to manifest as greater reproductive output.

  6. Fish Farm Pollution - A Study of Clean-up Options in Vietnam

    OpenAIRE

    Vo Thi Lang; Ky Quang Vinh; Ngo Thi Thanh Truc

    2009-01-01

    Aquaculture is a thriving industry in the Mekong Delta (MD) of Vietnam. Tra fish are the most popular catfish species bred in the region and they have become an important export item. As such they are an economically valuable product for many MD farmers. However, catfish farming is causing problems for the environment. Waste, especially wastewater, from fish farms is often not treated properly and is dumped into canals, creeks or rivers. This has a negative impact on local communities that re...

  7. 26 CFR 1.1301-1T - Averaging of farm and fishing income (temporary).

    Science.gov (United States)

    2010-04-01

    ... income (temporary). (a) Overview. An individual engaged in a farming or fishing business may make a farm... averaging, over the prior three-year period (base years), all or a portion of the individual's current year... guidance, see § 1.1301-1(d)(1) through (3)(i). (ii) Example. The rules of this paragraph (d)(3) are...

  8. A finite element method for netting application to fish cages and fishing gear

    CERN Document Server

    Priour, Daniel

    2014-01-01

    This book describes a finite element method for netting that describes the relation between forces and deformation of the netting and takes into account forces due to the twine elasticity, the hydrodynamic forces, the catch effect, the mesh opening stiffness.

  9. Fish farming as an innovative strategy for promoting food security in drought risk regions of Zimbabwe

    Directory of Open Access Journals (Sweden)

    Elvin Shava

    2017-01-01

    Full Text Available This article examines the implementation of fish farming as an innovative and economic strategy for promoting food security and dietary diversities among vulnerable households in drought risk areas of Zimbabwe. The declining climatic conditions and lack of economic opportunities in Mwenezi district of Zimbabwe attracted the attention of three nongovernmental organisations (NGOs to implement fish farming as an innovative mechanism to stimulate food security and generate employment in the district. The article used a qualitative research approach that includes semi-structured interviews and secondary data. The purposive sampling technique was adopted to interview participants in Mwenezi district who were involved in fish farming to assess and explore the experiences and benefits they derive from such development projects. Results for the article revealed that fish farming was well embraced by local communities as it led to improvements in food security, household income and employment regeneration. The local government including traditional leadership (Chiefs and Headmen’s supported the NGO activities as they benefited local communities. The article concludes that although fish farming was instrumental in regenerating employment, some participants still fail to participate because of laziness and desire to maintain dependency syndrome. The article recommends the NGOs to launch awareness campaigns in rural communities and increase networking with the donor community which is fundamental in attracting sustainable funding. The government can also promote fish farming in vulnerable rural communities by providing funding and capacity building programmes.

  10. A Global Analysis of the Relationship between Farmed Seaweed Production and Herbivorous Fish Catch.

    Directory of Open Access Journals (Sweden)

    E James Hehre

    Full Text Available Globally, farmed seaweed production is expanding rapidly in shallow marine habitats. While seaweed farming provides vital income to millions of artisanal farmers, it can negatively impact shallow coral reef and seagrass habitats. However, seaweed farming may also potentially provide food subsidies for herbivorous reef fish such as the Siganidae, a valuable target family, resulting in increased catch. Comparisons of reef fish landings across the central Philippines revealed that the catch of siganids was positively correlated to farmed seaweed production whilst negatively correlated to total reef fish catch over the same period of time. We tested the generality of this pattern by analysing seaweed production, siganid catch, and reef fish catch for six major seaweed-producing countries in the tropics. We hypothesized that increased seaweed production would correspond with increased catch of siganids but not other reef fish species. Analysis of the global data showed a positive correlation between farmed seaweeds and siganids in Southeast Asia (Indonesia, Malaysia, and the Philippines but not Africa (Tanzania and Zanzibar, or the Western Pacific (Fiji. In Southeast Asia, siganid catch increased disproportionately faster with seaweed production than did reef fish catch. Low continuity, sporadic production and smaller volumes of seaweed farming may explain the differences.

  11. The Implications of Ranaviruses to European farmed and wild freshwater fish

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    describing the risk of introduction and spread of exotic ranaviruses in European wild and farmed aquatic ecosystems Objectives 1 and 2 have been addressed by experimental trials involving bath challenges of both European farmed and wild fish species and ornamental fish species. The results showed that some...... and susceptibility trials in fish, and discussed in the context of taxonomy and legislation. Objective 3 was addressed by using the principles from the OIE risk assessment framework to develop a generic risk model for assessing the risk of introducing exotic ranaviruses into the EU via imports of infected ornamental...... in the introduction pathway. The pathway and the hazard identification were important outcomes of this model, together with the estimates of the risk of an exotic ranavirus being introduced into the EU by importation of ornamental fish from Asia. The risk for farmed fish is considered low, whereas the risk...

  12. Logistic Regression Analysis on Factors Affecting Adoption of Rice-Fish Farming in North Iran

    Directory of Open Access Journals (Sweden)

    Seyyed Ali NOORHOSSEINI-NIYAKI

    2012-06-01

    Full Text Available We evaluated the factors influencing the adoption of rice-fish farming in the Tavalesh region near the Caspian Sea in northern Iran. We conducted a survey with open-ended questions. Data were collected from 184 respondents (61 adopters and 123 non-adopters randomly sampled from selected villages and analyzed using logistic regression and multi-response analysis. Family size, number of contacts with an extension agent, participation in extension-education activities, membership in social institutions and the presence of farm workers were the most important socio-economic factors for the adoption of rice-fish farming system. In addition, economic problems were the most common issue reported by adopters. Other issues such as lack of access to appropriate fish food, losses of fish, lack of access to high quality fish fingerlings and dehydration and poor water quality were also important to a number of farmers.

  13. Size selectivity of sole gill nets fished in the North Sea

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Wileman, D.

    1999-01-01

    The size selectivity of sole nets was measured indirectly on a Danish commercial gill net vessel in the North Sea by using nets made in seven different mesh sizes fished simultaneously. Maximum likelihood procedure was used to fit different forms for the selection curve to the catch data for sole.......28 for sole, 2.60 for plaice and 4.56 for cod. Selection curves were also fitted to the catch data pooled over all sets. The model deviance for the sole and plaice data indicated lack of lit when pooling the catch data. (C) 1999 Elsevier Science B.V. All rights reserved....

  14. Increasing the Economical Efficiency and Sustainability of Indoor Fish Farming by Means of Aquaponics - Review

    Directory of Open Access Journals (Sweden)

    Flavius Blidariu

    2011-10-01

    Full Text Available This review focuses on increasing economical efficiency and sustainability of indoor fish farming. Aspects like sustainability and economical efficiency were reviewed. In order to improve man`s health we must reconsider the agricultural sciences, by this we understand that we must develop technologies friendly for the environment. Sustainable indoor fish farming is the farming of the new millennium. Combining aquaculture with hydroponics we obtain a new innovation named aquaponics which respects principles of sustainable agriculture (wastewater biofiltration by plants and gives us the possibility to increase economical efficiency with an additional production (organic vegetables.

  15. Impact of integrated fish farming on antimicrobial resistance in a pond environment

    DEFF Research Database (Denmark)

    Petersen, Andreas; Andersen, Jens Strodl; Kaewmak, T.

    2002-01-01

    investigated the impact of integrated fish farming on the levels of antimicrobial-resistant bacteria in a pond environment. One integrated broiler chicken-fish farm was studied for 2 months immediately after the start of a new fish production cycle. A significant increase over time in the resistance to six...... different antimicrobials was found for the indicator organism Acinetobacter spp. isolated from composite water-sediment samples. The initial resistance levels prior to the new production cycle were 1. to 5%. After 2 months the levels of resistance to oxytetracycline and sulfamethoxazole reached 100......%, and the levels of resistance to ciprofloxacin were more than 80%. The long-term effects of resistance on integrated farming were studied on seven additional farms. The resistance levels were particularly high among Enterococcus spp. and were also high among Acinetobacter spp. isolated from water-sediment samples...

  16. The Implications of Ranaviruses to European farmed and wild freshwater fish

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    -living fish. The following specific objectives are addressed: Objective 1: To determine the susceptibility of selected European freshwater fish to a panel of ranaviruses Objective 2: To determine whether ornamental fish are susceptible to or can be carriers of ranaviruses Objective 3: To develop a model...... describing the risk of introduction and spread of exotic ranaviruses in European wild and farmed aquatic ecosystems Objectives 1 and 2 have been addressed by experimental trials involving bath challenges of both European farmed and wild fish species and ornamental fish species. The results showed that some...... and susceptibility trials in fish, and discussed in the context of taxonomy and legislation. Objective 3 was addressed by using the principles from the OIE risk assessment framework to develop a generic risk model for assessing the risk of introducing exotic ranaviruses into the EU via imports of infected ornamental...

  17. Gill net selectivity and catch rates of pelagic fish in tropical coastal ...

    African Journals Online (AJOL)

    The fish species and size selectivity of gillnets design with monofilament nylon polyethylene netting materials were investigated in Lagos Lagoon, Nigeria between September and December 2005. The gillnets floats and sinkers were improvised from rubber slippers and lead metallic objects which were attached at intervals ...

  18. Energy self-reliance, net-energy production and GHG emissions in Danish organic cash crop farms

    DEFF Research Database (Denmark)

    Halberg, Niels; Dalgaard, Randi; Olesen, Jørgen E

    2008-01-01

    -energy production were modeled. Growing rapeseed on 10% of the land could produce bio-diesel to replace 50-60% of the tractor diesel used on the farm. Increasing grass-clover area to 20% of the land and using half of this yield for biogas production could change the cash crop farm to a net energy producer......Organic farming (OF) principles include the idea of reducing dependence of fossil fuels, but little has been achieved on this objective so far in Danish OF. Energy use and greenhouse gas (GHG) emissions from an average 39 ha cash crop farm were calculated and alternative crop rotations for bio......, and reduce GHG emissions while reducing the overall output of products only marginally. Increasing grass-clover area would improve the nutrient management on the farm and eliminate dependence on conventional pig slurry if the biogas residues were returned to cash crop fields...

  19. Intensive fish farming and the evolution of pathogen virulence: the case of columnaris disease in Finland.

    Science.gov (United States)

    Pulkkinen, K; Suomalainen, L-R; Read, A F; Ebert, D; Rintamäki, P; Valtonen, E T

    2010-02-22

    Ecological changes affect pathogen epidemiology and evolution and may trigger the emergence of novel diseases. Aquaculture radically alters the ecology of fish and their pathogens. Here we show an increase in the occurrence of the bacterial fish disease Flavobacterium columnare in salmon fingerlings at a fish farm in northern Finland over 23 years. We hypothesize that this emergence was owing to evolutionary changes in bacterial virulence. We base this argument on several observations. First, the emergence was associated with increased severity of symptoms. Second, F. columnare strains vary in virulence, with more lethal strains inducing more severe symptoms prior to death. Third, more virulent strains have greater infectivity, higher tissue-degrading capacity and higher growth rates. Fourth, pathogen strains co-occur, so that strains compete. Fifth, F. columnare can transmit efficiently from dead fish, and maintain infectivity in sterilized water for months, strongly reducing the fitness cost of host death likely experienced by the pathogen in nature. Moreover, this saprophytic infectiousness means that chemotherapy strongly select for strains that rapidly kill their hosts: dead fish remain infectious; treated fish do not. Finally, high stocking densities of homogeneous subsets of fish greatly enhance transmission opportunities. We suggest that fish farms provide an environment that promotes the circulation of more virulent strains of F. columnare. This effect is intensified by the recent increases in summer water temperature. More generally, we predict that intensive fish farming will lead to the evolution of more virulent pathogens.

  20. Improving women's lives in Cambodia through fish on farms

    International Development Research Centre (IDRC) Digital Library (Canada)

    improving food security and nutrition? To find out, HKI and UBC conducted a randomized control trial involving 900 women farmers, whose farming practice was one of three types: the original HFP model; HFP plus fishponds; and a group of normal, unassisted farming practice. (control). By Zaman Talukder, Hou Kroeun and ...

  1. IMPACT OF HEAVY METAL TO FISH AQUACULTURE IN FLOATING NET CAGE IN CIRATA RESERVOIR, INDONESIA

    Directory of Open Access Journals (Sweden)

    Tri Heru Prihadi

    2008-06-01

    Full Text Available Utilization of Cirata Reservoir for fisheries aquaculture with floating net cage system has been increasing rapidly. Industrial waste existed along watershed brings significant heavy metal pollutant that flows and difficult to control. Consequences of such activities were reflected in the degradation of reservoir environment indicated by sedimentation, water quality degradation and fish mass mortality because of up welling. The objectives of this research were: 1 to obtain data and information on heavy metal content in Cirata Reservoir waters, and 2 to observe and understand the effect of heavy metal to the fish cultured in floating net cage to support aquaculture in floating net cage system. Water quality and fish histology analyses were the methodologies used in this research. Descriptive and laboratory analysis were carry out to analysis the data. Based on observation and descriptive analyses, the content of heavy metal in Cirata Reservoir was classified as worse. Concentration of Pb, Cr, Hg, and Cd in the sample of water and tilapia digestive organ becomes fragile. Infiltration of hemoglobin cell, necrosis, degeneration and pigmentation occurred in body organs when up welling happened. Beside that, during up-welling digestive organ become easily breakable resulted in fish mass mortality in floating net cage. The affinity of hemoglobin to the toxic gas was higher than to oxygen, therefore aeration was not affective and mass mortality cannot be avoided. This was because of various events that occured to the fish and the other water biota that encompassed regular diffusion, bio-magnification, and bio-concentration to fish.

  2. Mercury exposure and source tracking in distinct marine-caged fish farm in southern China.

    Science.gov (United States)

    Xu, Xiaoyu; Wang, Wen-Xiong

    2017-01-01

    Coasts of South China have experienced an unprecedented growth in its marine-caged fish industry. We analyzed mercury concentrations and stable mercury isotope ratios in fourteen fish species from two cage-cultured farms in Southern China. Total mercury concentrations of all species were lower than the human health screening values, but the human exposures through consumption of several carnivorous fish exceeded the USEPA's reference dose. Isotopic compositions in the sediment (δ202Hg: -1.45‰ to -1.23‰; Δ199Hg: -0.04‰ to -0.01‰) suggested that mercury in these farms were from coal combustion and industrial inputs. Commercial food pellets and fresh fish viscera provided the major sources of methylmercury to the farmed fish and dominated their mercury isotopic signatures. Non-carnivorous fish presented lower δ202Hg and Δ199Hg values than the carnivorous fish. Using a mixing model, we demonstrated that the majority of mercury in non-carnivorous species came from pellets and in carnivorous fish came from combined diets of pellets and viscera. Meanwhile, methylmercury concentrations and % methylmercury in the fish were positively correlated with δ202Hg values but not with Δ199Hg values, mainly because fish eating similar feeds maintained similar Δ199Hg values. Environmental influences of cage farming such as fish feces and uneaten viscera that continuously provide organic mercury to the environments need to be considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil.

    Science.gov (United States)

    Oliveira, Karen Figueiredo; Lacerda, Luiz Drude; Peres, Tiago Farias; Bezerra, Moises Fernandes; Dias, Francisco José da Silva

    2015-11-01

    This paper estimated the mercury (Hg), emission factor, and mass balance from caged fish farming in the Castanhão Reservoir, NE Brazil, based on monitoring of a typical farm of Nile tilapia (Oreochromis niloticus). The total Hg input to the farm reached 1.45 gHg ha(-1) year(-1), from which 0.21 gHg ha(-1) year(-1) was exported out as fish biomass, ultimately resulting in an emission factor of 1.24 gHg ha(-1) year(-1) for the reservoir or approximately 8.27 mgHg ton fish(-1) year(-1) produced. Most of the input came from aquafeeds with concentrations varying from 1.4 to 31.1 ng g(-1), depending on the type of aquafeed. The Hg concentrations in fish were very low and varied from 1.0 to 2.9 ng g(-1). These values are two orders of magnitude lower than the legal limit for human consumption. The estimated total annual discharge of Hg from farming into the reservoir is 174 g for 18,000 tons of fish produced and may reach 387 g when the reservoir reaches its total capacity (40,000 tons), which is expected to occur in 2020. The mass balance, considering the deposition and accumulation rates, showed that approximately 40% of the total Hg input accumulate in farm sediments (0.72 g ha(-1) year(-1)), which is approximately 60% of the deposition rate estimated through the sediment traps and suggests that 0.54 gHg ha(-1) year(-1) could eventually be transported out of the farm to the reservoir. Notwithstanding these facts, the total annual input of Hg from fish farming to the Castanhão Reservoir is less than 1.0% of the total input from anthropogenic sources.

  4. Performance of Azolla caroliniana Willd. and Salvinia auriculata Aubl. on fish farming effluent

    Directory of Open Access Journals (Sweden)

    JJ. Toledo

    Full Text Available The increasing release of untreated fish farming effluents into water courses that flow to the Pantanal wetlands in Mato Grosso (Brazil may drive this ecosystem to eutrophication. Therefore, the growth of Azolla caroliniana Willd. and Salvinia auriculata Aubl. in fish farming effluent and their effect on its quality were evaluated for 48 days in a greenhouse. The results were compared to those obtained in a nutrient rich solution (Hoagland ½ medium. Azolla caroliniana showed lower relative growth rate in fish farming effluent (0.020 d-1 than in Hoagland ½ medium (0.029 d-1. However, S. auriculata grew slightly better in fish farming effluent (0.030 d-1 than in Hoagland ½ medium (0.025 d-1. The species apparently contributed to reduce nitrate and phosphate concentration in Hoagland ½ medium. However, in fish farming effluent, only electrical conductivity and pH were reduced by plants compared to the control without plants. Thus, A. caroliniana and S. auriculata show low potential for improving effluent quality.

  5. Performance of Azolla caroliniana Willd. and Salvinia auriculata Aubl. on fish farming effluent.

    Science.gov (United States)

    Toledo, J J; Penha, J

    2011-02-01

    The increasing release of untreated fish farming effluents into water courses that flow to the Pantanal wetlands in Mato Grosso (Brazil) may drive this ecosystem to eutrophication. Therefore, the growth of Azolla caroliniana Willd. and Salvinia auriculata Aubl. in fish farming effluent and their effect on its quality were evaluated for 48 days in a greenhouse. The results were compared to those obtained in a nutrient rich solution (Hoagland ½ medium). Azolla caroliniana showed lower relative growth rate in fish farming effluent (0.020 d-1) than in Hoagland ½ medium (0.029 d-1). However, S. auriculata grew slightly better in fish farming effluent (0.030 d-1) than in Hoagland ½ medium (0.025 d-1). The species apparently contributed to reduce nitrate and phosphate concentration in Hoagland ½ medium. However, in fish farming effluent, only electrical conductivity and pH were reduced by plants compared to the control without plants. Thus, A. caroliniana and S. auriculata show low potential for improving effluent quality.

  6. Farmed cod escapees and net-pen spawning left no clear genetic footprint in the local wild cod population

    Directory of Open Access Journals (Sweden)

    Rebekka Varne

    2015-11-01

    Full Text Available This study investigated a potential genetic introgression from farmed to wild cod Gadus morhua L. in the Trondheimsfjord, Norway. During the first 2 yr of operation of a cod farm in the inner part of the fjord, 2 large escape events and extensive pen spawning were reported. Analyses of 4 allozyme markers revealed no significant changes in allele frequencies between samples of wild cod before and after cod farming, although prominent allele frequency differences were demonstrated between wild and farmed samples. Analyses of 10 DNA markers showed a significant change between pre- and post-farming samples, due to contradictory allele frequency differences at Tch11, Pan I and Gmo132. Excluding those 3 markers due to null alleles (Tch11 and selection (Gmo132 and Pan I, the DNA markers paralleled the non-changed allele frequency signal from the allozymes. The topographies of the allozyme- and DNA-based dendrogram of the samples were congruent. Recaptures of tagged and released farmed cod indicated a seemingly random diffusion throughout the fjord and ended after approx. 6 mo. During an ongoing pen spawning, plankton net surveys sampling for cod eggs in the surroundings of the cod farm suggested the eggs originated from the farm. No larvae were present in the plankton samples. The apparent absence of introgression is explained relative to fitness and survival of pen-spawned larvae and adult escapees, and to a purging effect of the estuarine circulation of the Trondheimsfjord.

  7. Sources and fate of antimicrobials in integrated fish-pig and non-integrated tilapia farms

    DEFF Research Database (Denmark)

    Li, Kang; Liu, Liping; Zhan, Jia

    2017-01-01

    Antimicrobial contamination in aquaculture products constitutes a food safety hazard, but little is known about the introduction and accumulation of antimicrobials in integrated fish-pig aquaculture. This study, conducted in 2013, aimed to determine the residues of 11 types of antimicrobials...... by UPLC-MS/MS analysis in fish feed (n = 37), pig feed (n = 9), pig manure (n = 9), pond sediment (n = 20), fish skin (n = 20) and muscle tissue (n = 20) sampled from integrated tilapia-pig farms, non-integrated tilapia farms and fish feed supply shops. There was a higher occurrence of antimicrobial...... residues in fish skin from both integrated and non-integrated farms, and in pig manure. Enrofloxacin (3.9–129.3 μg/kg) and sulfadiazine (0.7–7.8 μg/kg) were commonly detected in fish skin and muscle, pig manure and pond sediment from integrated farms, with different types of antimicrobials found in pig...

  8. Derelict fishing nets in Puget Sound and the Northwest Straits: patterns and threats to marine fauna.

    Science.gov (United States)

    Good, Thomas P; June, Jeffrey A; Etnier, Michael A; Broadhurst, Ginny

    2010-01-01

    Derelict fishing gear remains in the marine environment for years, entangling, and killing marine organisms worldwide. Since 2002, hundreds of derelict nets containing over 32,000 marine animals have been recovered from Washington's inland waters. Analysis of 870 gillnets found many were derelict for years; most were recovered from northern Puget Sound and high-relief rocky habitats and were relatively small, of recent construction, in good condition, stretched open, and in relatively shallow water. Marine organisms documented in recovered gillnets included 31,278 invertebrates (76 species), 1036 fishes (22 species), 514 birds (16 species), and 23 mammals (4 species); 56% of invertebrates, 93% of fish, and 100% of birds and mammals were dead when recovered. For all taxa, mortality was generally associated with gillnet effectiveness (total area, age and condition, and suspension in the water). Mortality from derelict fishing gear is underestimated at recovery and may be important for species of economic and conservation concern. Published by Elsevier Ltd.

  9. PMCV and PRV occurrence in wild and farmed fish in Denmark

    DEFF Research Database (Denmark)

    Mikkelsen, Susie Sommer; Arnö, J.; Bruun, Morten Sichlau

    Muscle Inflammation (HSMI) and Cardiomyopathy Syndrome (CMS), respectively. In 2013, broodstock from four different rivers in Denmark were received for surveillance. These rivers are Ribe, Varde, Skjern and Store Å, which are all west-facing rivers. Of these fish 8 were Sea Trout and the rest Salmon. 184...... fish were tested by real-time RT-PCR for PRV and 30 fish from each river were tested by real-time RT-PCR for PMCV. This is the first time wild and farmed fish have been tested for either virus in Denmark....

  10. Economic and Environmental Impacts of Improving Growth Rate and Feed Efficiency in Fish Farming Depend on Nitrogen and Density Limitation

    NARCIS (Netherlands)

    Besson, M.; Komen, H.; Vandeputte, M.; Aubin, J.; Boer, de I.J.M.; Arendonk, van J.A.M.

    2014-01-01

    The aim of fish breeding is to increase profit by producing faster growing fish with lower feed intake. However, little is known about the economic and environmental impacts of selective breeding programs for fish. We modelled a fish farm producing African catfish in a Recirculating Aquaculture

  11. Fishing Farmers or Farming Fishers? Fishing Typology of Inland Small-Scale Fishing Households and Fisheries Management in Singkarak Lake, West Sumatra, Indonesia

    Science.gov (United States)

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P.

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  12. Fishing farmers or farming fishers? Fishing typology of inland small-scale fishing households and fisheries management in singkarak lake, west sumatra, indonesia.

    Science.gov (United States)

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  13. Numerical modelling of organic waste dispersion from fjord located fish farms

    Science.gov (United States)

    Ali, Alfatih; Thiem, Øyvind; Berntsen, Jarle

    2011-07-01

    In this study, a three-dimensional particle tracking model coupled to a terrain following ocean model is used to investigate the dispersion and the deposition of fish farm particulate matter (uneaten food and fish faeces) on the seabed due to tidal currents. The particle tracking model uses the computed local flow field for advection of the particles and random movement to simulate the turbulent diffusion. Each particle is given a settling velocity which may be drawn from a probability distribution according to settling velocity measurements of faecal and feed pellets. The results show that the maximum concentration of organic waste for fast sinking particles is found under the fish cage and continue monotonically decreasing away from the cage area. The maximum can split into two maximum peaks located at both sides of the centre of the fish cage area in the current direction. This process depends on the sinking time (time needed for a particle to settle at the bottom), the tidal velocity and the fish cage size. If the sinking time is close to a multiple of the tidal period, the maximum concentration point will be under the fish cage irrespective of the tide strength. This is due to the nature of the tidal current first propagating the particles away and then bringing them back when the tide reverses. Increasing the cage size increases the likelihood for a maximum waste accumulation beneath the fish farm, and larger farms usually means larger biomasses which can make the local pollution even more severe. The model is validated by using an analytical model which uses an exact harmonic representation of the tidal current, and the results show an excellent agreement. This study shows that the coupled ocean and particle model can be used in more realistic applications to help estimating the local environmental impact due to fish farms.

  14. Favored use of anti-predator netting (APN) applied for the farming of clams leads to little benefits to industry while increasing nearshore impacts and plastics pollution.

    Science.gov (United States)

    Bendell, L I

    2015-02-15

    An overview of the efficacy of anti-predator netting (APN) used by the shellfish industry is presented. There is little support that the currently favored APN effectively protects farmed clams from predators. Evidence does suggest that APN leads to impacts and pollution. APN is an attractant for predators, e.g., crabs, by providing a refuge within Ulva sp. which attaches onto the surface of APN. APN entrains silt and organic matter and increases sediment temperatures degrading habitat underneath the APN. APN present hazards to fish and wildlife and is a source of plastics to the marine environment. The continued use of ineffective APN does not serve either the environment or industry well, and many of these issues could be addressed through the alternate use of "ancient" technology used by aboriginal people to maintain clam gardens; building of rock walls optimizing the amount of clam habitat thereby increasing numbers without the use of APN. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Welfare of farmed fish - nutrition, breeding and diseases

    DEFF Research Database (Denmark)

    Buchmann, Kurt

    Proceeding on the workshop on Welfare of fish which was organised by the research school SCOFDA at KU-LIFE on April 11 and 12, 2007. Prooceedings comprise a total of 18 abstracts which were edited by Kurt Buchmann.......Proceeding on the workshop on Welfare of fish which was organised by the research school SCOFDA at KU-LIFE on April 11 and 12, 2007. Prooceedings comprise a total of 18 abstracts which were edited by Kurt Buchmann....

  16. Long-term effects of an offshore wind farm in the North Sea on fish communities

    DEFF Research Database (Denmark)

    Stenberg, Claus; Støttrup, Josianne; Deurs, Mikael van

    2015-01-01

    Long-term effects of the Horns Rev 1 offshore wind farm (OWF) on fish abundance, diversity and spatial distribution were studied. This OWF is situated on the Horns Reef sand bank in the North Sea. Surveys were conducted in September 2001, before the OWF was established in 2002, and again...... but declined in the control area 6 km away. None of the key fish species or functional fish groups showed signs of negative long-term effects due to the OWF. Whiting and the fish group associated with rocky habitats showed different distributions relative to the distance to the artificial reef structures...... introduced by the turbines. Rocky habitat fishes were most abundant close to the turbines while whiting was most abundant away from them. Species diversity was significantly higher close to the turbines. Overall, these results indicate that the artificial reef structures were large enough to attract fish...

  17. Regional differences in hypertensive cardiovascular remodeling between fishing and farming communities in Japan.

    Science.gov (United States)

    Yano, Yuichiro; Hoshide, Satoshi; Tamaki, Noboru; Inokuchi, Takashi; Nagata, Masahiko; Yokota, Naoto; Hidaka, Toshiaki; Kanemaru, Yoshimasa; Matsuda, Shuntaro; Kuwabara, Masachika; Shimada, Kazuyuki; Kario, Kazuomi

    2011-04-01

    Effects of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) intake on the cardiovascular system have been reported, and thus we hypothesized that the prevalence of hypertensive cardiovascular remodeling would be lower in a fishing than a farming community. We recruited 263 essential hypertensives from a fishing and 333 from a farming village; all subjects were ≥40 years (mean 73 years; 42% men). They were cross-sectionally examined for serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), asymmetric dimethylarginine (ADMA) levels, left ventricular mass index (LVMI), and common-carotid artery (CCA) and internal-carotid artery (ICA) intima-media thickness (IMT). Compared to the patients in the farming village, those in the fishing village had higher serum EPA and DHA levels (63.3 vs.70.9 µg/ml, 137.2 vs.157.8 µg/ml) and lower ADMA levels (0.49 vs.0.47 nmol/ml; all P farming village (113.2 vs.121.6 g/m(2), 0.88 vs.0.94 mm, 1.10 vs.1.17 mm: all P analysis showed that the difference in place of residence was independently associated with LVMI as well as with both CCA-IMT and ICA-IMT levels (all P farming community. Further investigations are required to explain the mechanisms underlying this association.

  18. Using copper sulfate to control egg fungus at Keo Fish Farm

    Science.gov (United States)

    Keo Fish Farm is the biggest producer of hybrid striped bass fry in the world. The hatchery manager asked about treatments to control fungus on eggs which occurred fairly often. Our lab has been working on gaining FDA-approval to use copper sulfate to control fungus on catfish eggs, so we were con...

  19. Physiological responses of the seagrass Posidonia oceanica as indicators of fish farm impact

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Marta [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain); Garcia, Tania [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain)], E-mail: irulagun@hotmail.com; Invers, Olga [Departament d' Ecologia, Universitat de Barcelona Avda. Diagonal 645, 08028 Barcelona (Spain); Ruiz, Juan Manuel [Instituto Espanol de Oceanografia C/Varadero 1, 30740 San Pedro del Pinatar, Murcia (Spain)

    2008-05-15

    The development of aquaculture along the Mediterranean coastline degrades the marine environment, in particular Posidonia oceanica meadows, which, in extreme cases, show high mortality. Here we studied the effects of organic matter and nutrient input from the effluents of three fish farms, located along the Mediterranean coast, on P. oceanica physiology. For this purpose, we measured physiological variables such as total nitrogen (N) content, free amino acid (FAA) concentration and composition, N stable isotope ratio ({delta}{sup 15}N), total phosphorus (P) content and total non-structural carbohydrate (TNC) content in plant tissues and epiphytes affected by organic discharges (highly impacted stations: HI, and less impacted stations: LI) and compared these results with those obtained in references sites (control stations: C). For all the descriptors analyzed in P. oceanica epiphytes, the values recorded in the vicinity of cages were, in general, much higher than those in C. Leaves did not respond consistently in any case. Total N content and {delta}{sup 15}N in epiphytes together with the total P content in rhizomes and epiphytes were the physiological descriptors that showed the most consistent responses to fish farm effluents. On the basis of these observations, we conclude that fish farm activities strongly affect the physiological parameters of nearby P. oceanica meadows. We propose that changes in these physiological parameters may be useful indicators of marine environmental degradation in studies that monitor the effects of fish farming.

  20. Yersiniosis outbreak in rainbow trout at fish farm in Oromia Regional ...

    African Journals Online (AJOL)

    This study presents the results of an investigation conducted on an outbreak of Yersiniosis (Enteric red mouth disease) caused by Yersinia ruckeri at a rainbow trout farm situated at Adaba, Oromia Regional State, Ethiopia. Seven diseased rainbow trout fish having average weight 80 - 100 grams and aged 9 months, were ...

  1. Effects on salmon (Salmo salar) from different operational procedures in fish farming

    OpenAIRE

    Bjordal, Åsmund; Fernö, Anders; Furevik, Dag M.; Huse, Ingvar

    1988-01-01

    The effects on farmed salmon caused by operational procedures as handling, de-lousing, removal of dead fish, grading and transfer were studied by underwater TV-observations, ultrasonic telemetry of heart rate and analyses of blood cortisol level. Handling and de-lousing were identified as important stressors.

  2. MOLECULAR GENETIC MARKERS AND METHODS OF THEIR IDENTIFICATION IN MODERN FISH-FARMING

    Directory of Open Access Journals (Sweden)

    I. Hrytsyniak

    2014-03-01

    Full Text Available Purpose. The application of molecular genetic markers has been widely used in modern experimental fish-farming in recent years. This methodology is currently presented by a differentiated approach with individual mechanisms and clearly defined possibilities. Numerous publications in the scientific literature that are dedicated to molecular genetic markers for the most part offer purely practical data. Thus, the synthesis and analysis of existing information on the general principles of action and the limits of the main methods of using molecular genetic markers is an actual problem. In particular, such a description will make it possible to plan more effectively the experiment and to obtain the desired results with high reliability. Findings. The main types of variable parts of DNA that can be used as molecular genetic markers in determining the level of stock hybridization, conducting genetic inventory of population and solving other problems in modern fish-farming are described in this paper. Also, the article provides an overview of principal modern methods that can be used to identify molecular genetic markers. Originality. This work is a generalization of modern ideas about the mechanisms of experiments with molecular genetic markers in fish-farming. Information is provided in the form of consistent presentation of the principles and purpose of each method, as well as significant advances during their practical application. Practical value. The proposed review of classic and modern literature data on molecular genetic markers can be used for planning, modernization and correction of research activity in modern fish-farming.

  3. Whole Farm Net Greenhouse Gas Abatement from Establishing Kikuyu-Based Perennial Pastures in South-Western Australia

    Directory of Open Access Journals (Sweden)

    David G. Masters

    2012-08-01

    Full Text Available On-farm activities that reduce GHG emissions or sequester carbon from the atmosphere to compensate for anthropogenic emissions are currently being evaluated by the Australian Government as carbon offset opportunities. The aim of this study was to examine the implications of establishing and grazing Kikuyu pastures, integrated as part of a mixed Merino sheep and cropping system, as a carbon offset mechanism. For the assessment of changes in net greenhouse gas emissions, results from a combination of whole farm economic and livestock models were used (MIDAS and GrassGro. Net GHG emissions were determined by deducting increased emissions from introducing this practice change (increased methane and nitrous oxide emissions due to higher stocking rates from the soil carbon sequestered from growing the Kikuyu pasture. Our results indicate that livestock systems using perennial pastures may have substantially lower net GHG emissions, and reduced GHG intensity of production, compared with annual plant-based production systems. Soil carbon accumulation by converting 45% of arable land within a farm enterprise to Kikuyu-based pasture was determined to be 0.80 t CO2-e farm ha−1 yr−1 and increased GHG emissions (leakage was 0.19 t CO2-e farm ha−1 yr−1. The net benefit of this practice change was 0.61 t CO2-e farm ha−1 yr−1 while the rate of soil carbon accumulation remains constant. The use of perennial pastures improved the efficiency of animal production almost eight fold when expressed as carbon dioxide equivalent emissions per unit of animal product. The strategy of using perennial pasture to improve production levels and store additional carbon in the soil demonstrates how livestock should be considered in farming systems as both sources and sinks for GHG abatement.

  4. Piscicultura. Productor Comercial de Peces. Guia Tecnica. Documento de trabajo, Programa de Educacion Agricola (Fish Farming. Commercial Fish Producer. Technical Guide. Curriculum Document, Agriculture Education Program).

    Science.gov (United States)

    Puerto Rico State Dept. of Education, Hato Rey. Area for Vocational and Technical Education.

    This curriculum guide begins with an introduction, course description, and description of the occupation of commercial fish farmer. A course outline covers five units: starting a business, establishing the fish farm, managing the enterprise, harvesting the fish, and administering the business. For each unit, the following are provided: terminal…

  5. Parasites of marine, freshwater and farmed fishes of Portugal: a review

    Directory of Open Access Journals (Sweden)

    Jorge da Costa Eiras

    Full Text Available Abstract An extensive literature review is made of the parasites in marine and freshwater fish in mainland Portugal, the Portuguese archipelagos of the Azores and Madeira, as well as in farmed fish. The host(s of each parasite species, its location in the host, site of capture of the host, whenever possible, and all the available bibliographic references are described. The economic importance of some parasites and the zoonotic relevance of some parasitic forms are discussed. A general overview of the data is provided, and some research lines are suggested in order to increase and complement the current body of knowledge about the parasites of fish from Portugal.

  6. Introduction, expansion and coexistence of epidemic Flavobacterium psychrophilum lineages in Chilean fish farms.

    Science.gov (United States)

    Avendaño-Herrera, Ruben; Houel, Armel; Irgang, Rute; Bernardet, Jean-François; Godoy, Marcos; Nicolas, Pierre; Duchaud, Eric

    2014-06-04

    Chile is one of the countries where the development of salmonid farming has been the most successful. The first importation of salmonids in Chile from the northern hemisphere dates back to the late 19th century and the country now ranks as the world second largest producer of farmed salmon. However, the fast increase of infections caused by the bacterium Flavobacterium psychrophilum is a growing concern for this local industry. This pathogen, also recognized as an important problem worldwide, has been first reported in Chile in 1993 and is currently affecting all three cultivated salmonid species: Atlantic salmon (Salmo salar), Coho salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss). Here we conducted a MLST (multi-locus sequence typing) analysis of the local genetic diversity of F. psychrophilum to better understand its origin and propagation in the country, and to suggest practices that could contribute to its control in the future. A total of 94 bacterial isolates, collected from the main production zones, were analyzed and compared to those of other origins already available. The data reveal the country-wide distribution of several genotypes closely related to those that are the most prevalent in European and North American fish farms, and overlapping host fish species of the different lineages. This population structure is probably the direct consequence of local fish farming practices that relied until recently on massive import of fish eggs (e.g., 78 million of eggs in 2012) and where mixed-species farms and fish transportation across the country are common. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. CH4 Emission Model from Bos Primigenius Waste in Fish-Water: Implications for Integrated Livestock-Fish Farming Systems

    Directory of Open Access Journals (Sweden)

    Joshua O. Okeniyi

    2013-07-01

    Full Text Available This paper studies a methane (CH4 emission model from the waste of cattle (B. primigenius based on trends in integrated livestock-fish farming adoption by farmers in Nigeria. Dung of B. primigenius was employed as substrate in fish-water, obtained from a fish-rearing farm, as a matrix medium for simulating a low-oxygen wastewater environment of an agriculture-aquaculture system. A substrate to fish-water mass ratio of 1:3 was used, developed in a laboratory-size digesting reactor system. Volumetric readings, at ambient temperature conditions and with a retention time of thirty-two days, were then subjected to the logistic probability density function, and tested against correlation coefficient and Nash-Sutcliffe coefficient of efficiency criteria. The readings show that a volume of CH4-containing gas as high as 65.3 x 10−3 dm3 was produced on the 13th day from the B. primigenius substrate. Also, production of 234.59 x 10−3 dm3/kg CH4-containing gas, totaling 703.76 x 10−3 dm3, was observed through the studied retention time. The 60% CH4 constituent model of the measured gas generation showed a potency of 2.0664 kg emission per animal, which is equivalent to 43.3944 CO2eq of global warming potential (GWP annually per animal. This bears environmental and climate change implications, and therefore alternative sustainable practices for integrated livestock-fish farming adoption are suggested.

  8. An opinion paper: emphasis on white muscle development and growth to improve farmed fish flesh quality.

    Science.gov (United States)

    Videler, J J

    2011-06-01

    Due to rapid depletion of wild stocks, the necessity to cultivate fish is eminent. Current fish farming practices seek to improve flesh quality. The notion that white muscles are the main target of the fishing industry is emphasized. A novel approach is suggested based on the development of white muscles in wild fish from eggs to adults. A compilation of facts about white muscle structure, function and ontogeny is followed by an account of the changes in swimming behaviour and performance related to the use of white muscle during growth from larva to adult. Ecological data narrate early swimming performance with white muscle development and growth, unveiling some of the important natural selection factors eliminating weak swimmers and poor growers from the breeding stock. A comparison between fish culture practise and natural conditions reveals fundamental differences. New approaches following wild breeding processes promise several important advantages regarding the quality of white muscle.

  9. Economic efficiency in fish farming: hope for agro-allied industries in Niagara

    Science.gov (United States)

    Kareem, R. O.; Dipeolu, A. O.; Aromolaran, A. B.; Williams, S. B.

    2008-02-01

    The challenge to increase the efficiency in food production level in Nigeria appears to be more urgent now than it has ever been in the history of the country. This is in view of the rapidly increasing population, the imminent decline in international economic and food aid and the need to conserve foreign exchange earnings through the production of raw materials to feed the growing industrial sector calls for urgent attention. The study was carried out in Ogun State. The descriptive statistics was used to determine the socio-economic characteristics of the respondents. The stochastic frontiers production analysis was applied to estimate the technical, allocative efficiency and economic efficiency among the fish farmers in the state. The results of economic efficiency revealed that fish farming is economically efficient with a range of between 55% and 84% efficiency level suggesting a favourable hope for the agro-allied industry such as poultry and cottage industries etc in the state. The result of hypothesis of inefficiency sources models showed that years of experience of fish farmers is significant at 1% probability level indicating the factor contributing to the fish farming experience in the state. Thus, the efficiency is due to the fact that farmers are experienced and fairly educated. On the basis of findings, policy is suggested to be directed towards the encouragement of entrepreneurs in fish farming in the state by providing enabling environment like credit facilities, public enlightenment programme and provision of social amenities like feeder roads, pipe-born water etc and given the fact that an increase in the level of formal education variable leads to less inefficiency, government policy should be focused on adopting the best technology (e.g. fast growing species and equipment) so as to improve the level of efficiency and investment which shall eventually lead to growth in output of fish farming and a lead to the establishment of agro

  10. Low Prevalence of netB and tpeL in Historical Clostridium perfringens Isolates from Broiler Farms in Alabama.

    Science.gov (United States)

    Bailey, M A; Macklin, K S; Krehling, J T

    2015-03-01

    The discovery of novel Clostridium perfringens toxins NetB and TpeL has initiated questions regarding their role in the pathogenesis of disease. However, data showing the prevalence of these genes in C. perfringens populations are limited to certain geographical areas. If netB and tpeL are important virulence factors for disease worldwide, one would expect to find these genes in isolates from other regions as well. To address this hypothesis, C. perfringens isolates collected from Alabama broiler farms over 15 yr ago were toxin genotyped using PCR. Each isolate was screened for netB and tpeL; the major lethal toxin genes cpa, cpb, etx, and ia; and the enterotoxin gene cpe. Results of the assay showed all isolates presumed to be C. perfringens were genotypically type A, cpe negative except for one broiler litter isolate, which was genotypically type C. Only two isolates were positive for netB. Similarly, only two isolates were positive for tpeL, one of which was also netB positive. The low incidence observed for netB and tpeL indicates that these genes are not significant virulence factors for the sampled population.

  11. Detrimental effect of cypermethrin treated nets on Culicoides populations (Diptera; Ceratopogonidae) and non-targeted fauna in livestock farms.

    Science.gov (United States)

    Del Río, R; Barceló, C; Lucientes, J; Miranda, M A

    2014-01-31

    Bluetongue (BT) is an important disease of ruminants which exhibits its most severe clinical signs on cattle and especially on certain breeds of sheep. The known vectors of BT are small insects of the genus Culicoides (Diptera; Ceratopogonidae). Two species from this genus - Culicoides imicola and Culicoides obsoletus - play the major role in the transmission of the disease in Europe. Several prophylactic methods are used to avoid transmission; however, an easy and cost-effective preventive technique would be very useful for the control of the Culicoides populations near the animals. In the present study, the insecticide effect of cypermethrin treated nets on a Culicoides population was evaluated. A polyethylene net sprayed with 1L cypermethrin solution (1%) surrounding a UV light suction trap was placed at a cattle farm in Majorca (Balearic Islands). Collections of Culicoides and other fauna from the trap and floor around the net were compared with a control. Results showed no significant differences in the collection of Culicoides midges between the insecticide-treated net and the control. However, significant differences were observed in the collection of the non-target fauna between the treated net and the control, indicating that the dose used in the present trial was enough to kill most of the arthropods that contacted the net. The reasons for these equivocal findings and means to improve this technique for the control of Culicoides midges are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Farmed and wild fish in the prevention of cardiovascular diseases: assessing possible differences in lipid nutritional values.

    Science.gov (United States)

    Cahu, C; Salen, P; de Lorgeril, M

    2004-02-01

    The consumption of fish and fish-derived products is recommended as a means of preventing cardiovascular and other diseases, and has considerably increased over recent decades. However, as the world's wild fish stocks are limited, consumers are now being proposed farmed fish as an alternative. The aim of this study was to compare the fat composition of farmed and wild fish in order to estimate whether the expected health effects of the former (especially in relation to cardiovascular diseases) are potentially the same as those of the latter. The data presented in this paper were collected from the recently published literature. The lipid composition of farmed fish is more constant and less affected by seasonal variations than that of wild fish because, as it is largely dependent on the fatty acid composition of their feed, it can be customised by adjusting dietary intakes. Vegetable food is increasingly replacing fishmeal in fish feeds, and may induce a relative decrease in n-3 polyunsaturated fatty acids (PUFAs), expressed as a percentage of total fatty acids. However, as farmed fish generally have higher total lipid levels than wild fish, 100 g of farmed fish fillet can provide a higher amount of n-3 PUFAs (especially EPA and DHA) than 100 g of wild fish. Furthermore, quite high levels of (alpha-tocopherol in farmed fish can theoretically provide better EPA and DHA protection against peroxidation. Sensory analyses by trained consumer panels have not revealed any significant differences between wild and farmed fish. Moreover, fresh fish storage conditions (including the time from slaughtering to consumer sales) are more easily verifiable in the case of farmed fish, in which the content of potentially toxic heavy metals (a major health concern in certain areas) is also theoretically more easily controlled. Provided that they are raised under appropriate conditions, the nutritional content of farmed fish is at least as beneficial as that of wild fish (particularly

  13. Effects of fish farm waste on Posidonia oceanica meadows: Synthesis and provision of monitoring and management tools

    Energy Technology Data Exchange (ETDEWEB)

    Holmer, Marianne [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)], E-mail: holmer@biology.sdu.dk; Argyrou, Marina [Marine Environment Division, Department of Fisheries and Marine Research, Ministry of Agriculture, Natural Resources and Environment, 101 Bethleem Street, 1416 Nicosia (Cyprus); Dalsgaard, Tage [Department of Marine Ecology, National Environmental Research Institute, Aarhus University, Vejlsovej 25, P.O. Box 314, DK-8600 Silkeborg (Denmark); Danovaro, Roberto [Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Diaz-Almela, Elena; Duarte, Carlos M. [IMEDEA (CSIC-UIB), Miquel Marques 21, 07190 Esporles (Illes Balears) (Spain); Frederiksen, Morten [Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Grau, Antoni [Direccio General de Pesca, Conselleria d' Agricultura i Pesca, Govern de les Illes Balears, Foners 10, 07006 Palma de Mallorca (Illes Balears) (Spain); Karakassis, Ioannis [Marine Ecology Laboratory, Biology Department, University of Crete, Heraklion, 71409 Crete (Greece); Marba, Nuria [IMEDEA (CSIC-UIB), Miquel Marques 21, 07190 Esporles (Illes Balears) (Spain); Mirto, Simone [Institute for the Marine Coastal Environment, National Council of Research, Spianata S. Raineri, 86, 98122 Messina (Italy); Perez, Marta [Departament d' Ecologia, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona (Spain); Pusceddu, Antonio [Department of Marine Science, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Tsapakis, Manolis [Institute of Oceanography, Hellenic Center for Marine Research, P.O. Box 2214, GR 71003 Heraklion, Crete (Greece)

    2008-09-15

    This paper provides a synthesis of the EU project MedVeg addressing the fate of nutrients released from fish farming in the Mediterranean with particular focus on the endemic seagrass Posidonia oceanica habitat. The objectives were to identify the main drivers of seagrass decline linked to fish farming and to provide sensitive indicators of environmental change, which can be used for monitoring purposes. The sedimentation of waste particles in the farm vicinities emerges as the main driver of benthic deterioration, such as accumulation of organic matter, sediment anoxia as well as seagrass decline. The effects of fish farming on P. oceanica meadows are diverse and complex and detected through various metrics and indicators. A safety distance of 400 m is suggested for management of P. oceanica near fish farms followed by establishment of permanent seagrass plots revisited annually for monitoring the health of the meadows.

  14. Tracing Asian seabass individuals to single fish farms using microsatellites.

    Directory of Open Access Journals (Sweden)

    Gen Hua Yue

    Full Text Available Traceability through physical labels is well established, but it is not highly reliable as physical labels can be easily changed or lost. Application of DNA markers to the traceability of food plays an increasingly important role for consumer protection and confidence building. In this study, we tested the efficiency of 16 polymorphic microsatellites and their combinations for tracing 368 fish to four populations where they originated. Using the maximum likelihood and Bayesian methods, three most efficient microsatellites were required to assign over 95% of fish to the correct populations. Selection of markers based on the assignment score estimated with the software WHICHLOCI was most effective in choosing markers for individual assignment, followed by the selection based on the allele number of individual markers. By combining rapid DNA extraction, and high-throughput genotyping of selected microsatellites, it is possible to conduct routine genetic traceability with high accuracy in Asian seabass.

  15. Response of phytoplankton to an experimental fish culture in net cages in a subtropical reservoir.

    Science.gov (United States)

    Bartozek, E C R; Bueno, N C; Feiden, A; Rodrigues, L C

    2016-01-01

    This study aimed to evaluate nutrients concentration and spatial-temporal changes in phytoplankton biovolume during an experimental fish culture in net cages in a lateral arm of Salto Caxias reservoir, Brazil. Two sampling stations were placed in the affected lateral arm and other two in a cageless lateral arm. Neither abiotic variables nor phytoplankton biovolume presented significant differences between the treatments. Only temporal changes were confirmed by the analysis performed. Both lateral arms were classified as oligotrophic, reflecting low influence of the net cages. Phytoplankton growth seems to be limited by nitrogen. Biovolume values were, in general, low and five major functional groups were recognized (E, F, G, K and P). In summer higher biovolume values were observed and representatives of Chlorophyceae and Cyanobacteria belonging to the functional groups F and K, respectively, were the most important. In winter phytoplankton was mainly composed by Bacillariophyceae taxa from P group. G group was also restricted to winter and E group occurred in winter and summer. The variations recorded in phytoplankton structure appear to have been mainly influenced by seasonal changes in temperature, precipitation and nutrients availability. The effects of net cages on the abiotic variables and phytoplankton biovolume appear to have been small, probably due to the small number of net cages employed and the system dilution capacity. However, a permanent monitoring of phytoplankton is recommended, since this environment has a carrying capacity, from which the trophic state may increase.

  16. Fish survey, fishing duration, and other data from gill nets, fyke nets, and other gear from NOAA Ship DISCOVERER and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 1982-07-25 to 1983-09-23 (NCEI Accession 8700139)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from gill nets, fyke nets, and other gear from NOAA Ship DISCOVERER and other platforms from 25 July...

  17. Farmed fish welfare-suffering assessment and impact on product quality

    Directory of Open Access Journals (Sweden)

    Bianca Maria Poli

    2010-01-01

    Full Text Available Fish welfare, suffering and the perception of pain were debated, together with several factors reducing infra vitam welfare of farmed fish (genetic, environment, density, malnutrition, starvation, cataracts, deformities, vaccination side effects, transport, handling, confinement, crowding, harvesting, killing method. Behavioural and physiological stress responses were considered as indicators of welfare reduction. The effects of pre-slaughter management practices, and the most commonly used stunning/slaughtering methods on welfare and quality reduction of farmed fish were discussed. A number of indicators can be used to assess fish welfare-suffering, both in a scientific and practical context, such as behavioural, haematic, cellular, tissue post mortem fish stress and quality indicators, but none of them are optimal. The best strategy for a reliable assessment of fish welfare/suffering and their impact on product quality is a multidisciplinary approach that takes into account animal behaviour and the different biochemical and physiological ante mortem and post mortem processes involved: several components, all influenced in a similar way by the same condition, suggest real welfare and quality reduction.

  18. THE ENVIRONMENTAL IMPACTS OF MARINE FISH CAGE FARMS IN THE EASTERN ADRIATIC

    Directory of Open Access Journals (Sweden)

    Ivan Katavić

    2003-12-01

    Full Text Available Mariculture in Croatia could play a more important role in development of rural communities along coastline. However, by increase of fish farming, public concern over environmental issues has been raised, and the need for more responsible mariculture development and management has been asked. There are opportunities and challenges for effectively integrating mariculture into coastal zone management with equal rights and obligations. This is primarily because of its social and economic mission consisting in preventing de-population of rural coastal areas and islands and meeting the growing needs of tourist market for seafood. Although intensive mariculture production is accused of producing negative environmental effects, many of these effects still need to be scientifically documented. The effect of nitrogen and phosphorous releases from farmed fish faeces or uneaten food is not of significant issues for marine ecosystem, and it is generally of little importance compared to the inflow of nutrients from other coastal sources. The impact on sediment and benthic communities is mainly local and short-term ones, and depends on the number and extent of the farms and their location. Recovery of some benthic communities after the cessation of farming activities may be delayed over several years (i. e. Posidonia beds due to the accumulated organic matter. Bluefin tuna farming if not properly located and managed might cause pollution problems, either from uneaten feed and metabolic waste or from harvesting and processing the fish. In most cases the problem comes from smell pollution during the summer time and the oily water surface that may be widespread much outside of the farm areas. It will be important for sustainable development of Croatian mariculture to offer a healthy and good quality product in the quantities required by the market, while not degrading the marine environment.

  19. Expanding the moral circle: farmed fish as objects of moral concern.

    Science.gov (United States)

    Lund, Vonne; Mejdell, Cecilie M; Röcklinsberg, Helena; Anthony, Ray; Håstein, Tore

    2007-05-04

    Until recently fish welfare attracted little attention, but international and national legislation and standards of fish welfare are now emerging and an overview of these developments is presented in this study. Whereas animal welfare legislation is based on public morality, animal ethics does not automatically accept public morality as normative and elaborates arguments regarding the way humans should treat animals (referred to as moral standards). In this study we present the most common animal ethics theories. For most of these, sentience is considered a demarcation line for moral concern: if an animal is sentient, then it should be included in the moral circle, i.e. receive moral consideration in its own right and some basic welfare should be ensured. As for fish, research has revealed that the sensory system of teleosts can detect noxious stimuli, and that some kind of phenomenal consciousness, allowing the fish to feel pain, seems to be present. This raises the ethical question as to how much evidence we need in order to act on such indications of fish sentience. A simple risk analysis shows that the probability that fishes can feel pain is not negligible and that if they do indeed experience pain the consequences in terms of the number of suffering individuals are great. We conclude that farmed fish should be given the benefit of the doubt and we should make efforts that their welfare needs are met as well as possible. Finally, the way forward is briefly discussed: efforts must be made to understand what fish welfare means in practical fish farming. This will involve the development of research and education, greater accountability and transparency, compliance with and control of policies, and quality assurance schemes.

  20. Diversity of farming systems integrating fish pond aquaculture in the province of Kinshasa in the Democratic Republic of the Congo

    Directory of Open Access Journals (Sweden)

    Patrick Mafwila Kinkela

    2017-06-01

    Full Text Available Agriculture and aquaculture systems are used by many farmers in various tropical countries of Asia, America and Africa. They have proven their relevancy to increase the productivity of farms by optimising nutrient fluxes and reducing requirements for external fertilisers. This article analysed the current state of fish farming and the way it is integrated with other farm subsystems in the urban/peri-urban and rural areas of Kinshasa, Democratic Republic of Congo. More precisely, it examined the allocation of resources at the farm level, the recovery of helophytes plants, and the fate of fish production choices and it explored the possibility of intensifying these existing integrated farming systems. After a census of ponds in the urban and rural areas of Kinshasa, an on-site survey was conducted on 150 fish pond farms to assess the different activities practiced on farms, the impact of integrating crops and livestock to fish pond aquaculture and the constraints of the system. A total of three thousand and twenty (3020 fish ponds were recorded in the urban and rural areas of Kinshasa. Among these farms integrated aquaculture-agriculture systems exist with a wide diversity of practices (about 79% of farms combined fish with livestock and/or vegetable production. No striking differences between fish farms according to the allocation of resources, fish production method such as monoculture or polyculture, the recovery of helophytes plants and the fate of fish production choice were found depending on the location. However, fish farms were differently managed when combined with agriculture and/or livestock. Regarding the integration of the different subsystems through nutrient fluxes, 11 different movements of material between subsystems were found in integrated farms. However, not all fluxes are equally used in all farms and therefore improvements cannot be generalised. Improvements to be explored are such as making better use of manure pond mud and

  1. Energy profiling of demersal fish: a case-study in wind farm artificial reefs.

    Science.gov (United States)

    De Troch, Marleen; Reubens, Jan T; Heirman, Elke; Degraer, Steven; Vincx, Magda

    2013-12-01

    The construction of wind farms introduces artificial hard substrates in sandy sediments. As Atlantic cod (Gadus morhua) and pouting (Trisopterus luscus) tend to aggregate in order to feed around these reefs, energy profiling and trophic markers were applied to study their feeding ecology in a wind farm in the Belgian part of the North Sea. The proximate composition (carbohydrates, proteins and lipids) differed significantly between liver and muscle tissue but not between fish species or between their potential prey species. Atlantic cod showed to consume more energy than pouting. The latter had a higher overall energy reserve and can theoretically survive twice as long on the available energy than cod. In autumn, both fish species could survive longer on their energy than in spring. Polyunsaturated fatty acids were found in high concentrations in fish liver. The prey species Jassa and Pisidia were both rich in EPA while Jassa had a higher DHA content than Pisidia. Energy profiling supported the statement that wind farm artificial reefs are suitable feeding ground for both fish species. Sufficient energy levels were recorded and there is no indication of competition.

  2. Perfluorinated compounds in fish and carryover from fishfeed to farmed rainbow trout

    DEFF Research Database (Denmark)

    Granby, Kit; Larsen, Bodil Katrine; Cederberg, Tommy Licht

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) bioaccumulate in humans and the half-life is around 4-6 years. As fish for many people is the largest source of PFOS exposure, the occurrence and the exposure of PFOS from fish was estimated. Today a significant proportion of the fish...... consumption is from aquaculture produce (~40% of the world’s fisheries (FAO 2012)). Hence the carryover of PFOS and PFOA from aquaculture feed to fish was studied. In 2011 and 2012 fish were collected from Danish catching areas in the Baltic Sea and the North Sea and from Danish aquaculture farms and analysed...... for PFOS and PFOA. The impact of chemical exposure on the cause in a feeding trial with rainbow trout (Oncorhynchus mykiss) accumulation and elimination of PFOS and PFOA was studied. PFOS was added to the fish feed at a level of 3 µg/g and PFOA at 0.5 µg/g. The fish were fed with the contaminated fish feed...

  3. Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier.

    Directory of Open Access Journals (Sweden)

    Izabel Cristina Dos Reis

    Full Text Available Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003-2013 was divided into two phases (epidemic and post-epidemic. Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011-2012 and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39. These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region.

  4. Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier.

    Science.gov (United States)

    Reis, Izabel Cristina Dos; Honório, Nildimar Alves; Barros, Fábio Saito Monteiro de; Barcellos, Christovam; Kitron, Uriel; Camara, Daniel Cardoso Portela; Pereira, Glaucio Rocha; Keppeler, Erlei Cassiano; da Silva-Nunes, Mônica; Codeço, Cláudia Torres

    2015-01-01

    Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county) to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003-2013) was divided into two phases (epidemic and post-epidemic). Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011-2012) and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39). These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region.

  5. Reduced carbon sequestration in a Mediterranean seagrass (Posidonia oceanica) ecosystem impacted by fish farming

    DEFF Research Database (Denmark)

    Apostolaki, E; Holmer, Marianne; Marbà, N

    2011-01-01

    We studied the relationship between sediment nutrient enrichment and carbon sequestration, using the ratio of gross primary production to respiration (P/R), in a fish-farming impacted and an unaffected Mediterranean seagrass (Posidonia oceanica) ecosystem in the Aegean Sea, Greece. Carbon (C...... enhanced in the impacted meadow throughout the year, even during winter when fish farming activity was low. In the impacted sediment, the increase in C and N was higher than P, reflecting a faster remineralization and uptake of P than C and N. The ecosystem P/R ratio decreased exponentially with sediment....... Such a regime shift indicates a loss of storage capacity of the seagrass ecosystem, jeopardizing the key role of P. oceanica as a carbon sink in the Mediterranean....

  6. Benthic recovery during open sea fish farming abatement in Western Mediterranean, Spain.

    Science.gov (United States)

    Sanz-Lázaro, Carlos; Marin, Arnaldo

    2006-12-01

    Fish farming is an important source of organic matter input in coastal waters, which contributes to eutrophication. In this study, the macrofaunal benthic community was studied after the cessation of fish farming with the aim of improving our understanding of benthic succession and sediment recovery in a marine ecosystem. The results showed that the best environmental variables for assessing organic pollution were acid-volatile sulfides (AVS) and redox potential. Succession and recovery was best explained by macrofaunal analysis based on community composition as well as on trophic groups. The patterns of recovery differed between each impacted station. For this reason, succession could not be accurately predicted due to the unique environmental parameters and the singular community functional structure of each location. The Azti Marine Benthic Index (AMBI) proved its validity for assessing pollution but did not distinguish between successional stages.

  7. Switching from monoculture to polyculture farming benefits birds in oil palm production landscapes: Evidence from mist netting data.

    Science.gov (United States)

    Yahya, Muhammad S; Syafiq, Muhamad; Ashton-Butt, Adham; Ghazali, Amal; Asmah, Siti; Azhar, Badrul

    2017-08-01

    Monoculture farming is pervasive in industrial oil palm agriculture, including those RSPO plantations certified as sustainably managed. This farming practice does not promote the maintenance of farmland biodiversity. However, little scientific attention has been given to polyculture farming in oil palm production landscapes. Polyculture farming is likely to increase the floristic diversity and stand structural complexity that underpins biodiversity. Mist nets were used to sample birds at 120 smallholdings in Peninsular Malaysia. At each site, 12 vegetation structure characteristics were measured. We compared bird species richness, abundance, and composition between monoculture and polyculture smallholdings and used predictive models to examine the effects of habitat quality on avian biodiversity. Bird species richness was significantly greater in polyculture than that of monoculture smallholdings. The number of fallen and standing, dead oil palms were also important positive predictors of species richness. Bird abundance was also strongly increased by standing and dead oil palms and decreased with oil palm stand height. Our results indicate that polyculture farming can improve bird species richness in oil palm production landscapes. In addition, key habitat variables that are closely associated with farming practices, such as the removal of dead trees, should and can be managed by oil palm growers in order to promote biodiversity. To increase the sustainability of oil palm agriculture, it is imperative that stakeholders modify the way oil palms are currently planted and managed. Our findings can guide policy makers and certification bodies to promote oil palm production landscapes that will function more sustainably and increase existing biodiversity of oil palm landscapes.

  8. Experimental infection of rainbow trout Oncorhynchus mykiss with viral haemorrhagic septicaemia virus isolates from European marine and farmed fishes

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Slierendrecht, W.J.; King, J.A.

    2004-01-01

    The susceptibility of rainbow trout Oncorhynchus mykiss to infection with various isolates of viral haemorrhagic septicaemia virus (VHSV) was examined. A total of 8 experiments with rainbow trout ranging from 0.6 to 6.2 g was conducted for 139 isolates originating from wild marine fishes...... in European waters (115 isolates), farmed turbot from Scotland and Ireland (2 isolates), and farmed rainbow trout (22 isolates). The isolates were tested by immersion and/or intraperitoneal injection either as pooled or single isolates. The isolates from wild marine fishes did not cause mortality by immersion...... while some of the isolates caused mortality when injected. All VHSV isolates from farmed rainbow trout caused significant mortality by immersion. Currently, pathogenicity trials are the only way to differentiate VHSV isolates from wild marine fishes and farmed rainbow trout. The 2 farmed turbot isolates...

  9. Design of water supply facilities for a tidal fish farm in the Niger Delta ...

    African Journals Online (AJOL)

    Design of water supply facilities for a tidal fish farm in the Niger Delta, Nigeria. ... Mean surface water temperature readings ranged from 23.50 to 29.00OC. Dissolved oxygen (DO) content ranged from 5.80 to 7.40 mg/L. The corresponding DO deficits ranged from 2.35 to 0.20 mg/L, indicating a moderate level of pollution.

  10. An industry-scale mass marking technique for tracing farmed fish escapees.

    Directory of Open Access Journals (Sweden)

    Fletcher Warren-Myers

    Full Text Available Farmed fish escape and enter the environment with subsequent effects on wild populations. Reducing escapes requires the ability to trace individuals back to the point of escape, so that escape causes can be identified and technical standards improved. Here, we tested if stable isotope otolith fingerprint marks delivered during routine vaccination could be an accurate, feasible and cost effective marking method, suitable for industrial-scale application. We tested seven stable isotopes, (134Ba, (135Ba, (136Ba, (137Ba, (86Sr, (87Sr and (26Mg, on farmed Atlantic salmon reared in freshwater, in experimental conditions designed to reflect commercial practice. Marking was 100% successful with individual Ba isotopes at concentrations as low as 0.001 µg. g-1 fish and for Sr isotopes at 1 µg. g-1 fish. Our results suggest that 63 unique fingerprint marks can be made at low cost using Ba (0.0002 - 0.02 $US per mark and Sr (0.46 - 0.82 $US per mark isotopes. Stable isotope fingerprinting during vaccination is feasible for commercial application if applied at a company level within the world's largest salmon producing nations. Introducing a mass marking scheme would enable tracing of escapees back to point of origin, which could drive greater compliance, better farm design and improved management practices to reduce escapes.

  11. BACTERIOLOGICAL PROPERTIES OF MARINE WATER IN ADRIATIC FISH FARMS: ENUMERATION OF HETEROTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    Emin Teskeredžić

    2012-12-01

    Full Text Available Aquaculture is currently one of the fastest growing food production sectors in the world. Increase in nutrients and organic wastes lead to general deterioration of water quality. The problem of water quality is associated with both physical and chemical factors, as well as microbiological water quality. Heterotrophic bacteria play an important role in the process of decomposition of organic matter in water environment and indicate eutrophication process. Here we present our experience and knowledge on bacterial properties of marine water in the Adriatic fish farms with European sea bass (Dicentrarchus labrax L., 1758, with an emphasis on enumeration of heterotrophic bacteria in marine water. We applied two temperatures of incubation, as well as two methods for enumeration of heterotrophic bacteria: substrate SimPlate® test and spread plate method on conventional artificial media (Marine agar and Tryptic Soy agar with added NaCl. The results of analysis of bacteriological properties of marine water in the Adriatic fish farms showed that enumeration of heterotrophic bacteria in marine water depends on the applied incubation temperature and media for enumeration. At the same time, the incubation temperature of 22C favours more intense growth of marine heterotrophic bacteria, whereas a SimPlate test gives higher values of heterotrophic bacteria. Volatile values of heterotrophic bacteria during this research indicate a possible deterioration of microbiological water quality in the Adriatic fish farms and a need for regular monitoring of marine water quality.

  12. An overall estimation of losses caused by diseases in the Brazilian fish farms.

    Science.gov (United States)

    Tavares-Dias, Marcos; Martins, Maurício Laterça

    2017-12-01

    Parasitic and infectious diseases are common in finfish, but are difficult to accurately estimate the economic impacts on the production in a country with large dimensions like Brazil. The aim of this study was to estimate the costs caused by economic losses of finfish due to mortality by diseases in Brazil. A model for estimating the costs related to parasitic and bacterial diseases in farmed fish and an estimative of these economic impacts are presented. We used official data of production and mortality of finfish for rough estimation of economic losses. The losses herein presented are related to direct and indirect economic costs for freshwater farmed fish, which were estimated in US$ 84 million per year. Finally, it was possible to establish by the first time an estimative of overall losses in finfish production in Brazil using data available from production. Therefore, this current estimative must help researchers and policy makers to approximate the economic costs of diseases for fish farming industry, as well as for developing of public policies on the control measures of diseases and priority research lines.

  13. Calcite Farming at Hollow Ridge Cave: Calibrating Net Rainfall and Cave Microclimate to Dripwater and Calcite Chemical Variability

    Science.gov (United States)

    Tremaine, D. M.; Kilgore, B. P.; Froelich, P. N.

    2012-04-01

    Stable isotope (δ18O and δ13C) and trace element records in cave speleothems are often interpreted as climate changes in rainfall amount or source, cave air temperature, overlying vegetation and atmospheric pCO2. However, these records are difficult to verify without in situ calibration of changes in cave microclimate (e.g., net rainfall, interior ventilation changes) to contemporaneous variations in dripwater and speleothem chemistry. In this study at Hollow Ridge Cave (HRC) in Marianna, Florida (USA), cave dripwater, bedrock, and modern calcite (farmed in situ) were collected in conjunction with continuous cave air pCO2, temperature, barometric pressure, relative humidity, radon-222 activity, airflow velocity and direction, rainfall amount, and drip rate data [1]. We analyzed rain and dripwater δD and δ18O, dripwater Ca2+, pH, δ13C and TCO2, cave air pCO2 and δ13C, and farmed calcite δ18O and δ13C to examine the relationships among rainwater isotopic composition, cave air ventilation, cave air temperature, calcite growth rate and seasonal timing, and calcite isotopic composition. Farmed calcite δ13C decreases linearly with distance from the front entrance to the interior of the cave during all seasons, with a maximum entrance-to-interior gradient of Δδ13C = -7‰ . A whole-cave "Hendy test" at distributed contemporaneous farming sites reveals that ventilation induces a +1.9 ± 0.96‰ δ13C offset between calcite precipitated in a ventilation flow path and out of flow paths. Farmed calcite δ18O exhibits a +0.82 ± 0.24‰ offset from values predicted by both theoretical calcite-water calculations and by laboratory-grown calcite [2]. Unlike calcite δ13C, oxygen isotopes show no ventilation effects and are a function only of temperature. Combining our data with other speleothem studies, we find a new empirical relationship for cave-specific water-calcite oxygen isotope fractionation across a range of temperatures and cave environments: 1000 ln α = 16

  14. SILVER CRUCIAN OR CHITON AND DAMAGES IT SAUSSES BY ITS PRESENCE ON FISH FARMS

    Directory of Open Access Journals (Sweden)

    Ljubomir Kajgana

    1996-06-01

    Full Text Available By its presence, silver crucian carp or chiton (Carassius auratus gibelio Bloch. makes lot of damage on fish-farms. By its nutrition way, the chiton competes with carp, thus reducing its growths and increasing the nutritive coefficient what is unjustified both economically and technologically. The diclinous and hermaphroditic way of procreation influences the spread of this species. After the dissection of an chiton exemplar of 10-12 dag in October 1995 in Našice “Ribnjak 1905” it was stated that it had 23% of male fish. Spawn was in the IV. stage of sex maturity according to Kiseljević. The ways of chiton coming and going to particular pounds as well as measures to control it are analyzed in the text. It is recommended to turn full attention to the filling and re-filling of pounds, prevent the coming of wild fish and fill canals and pounds thoroughly.

  15. LACTATE DEHYDROGENASE GENE GENOTYPIZATION FOR SPECIES IDENTIFICATION IN A FISH FARM ON THE RIVER NERETVA

    Directory of Open Access Journals (Sweden)

    Polonca Margeta

    2015-09-01

    Full Text Available There are severale Salmonid species, found in the river Neretva basin, among which S. trutta and S. obtusirostris. Also, natural hybrids such as S. obtusirostris x S. trutta have been observed. In one fish farm on the river Neretva, S. trutta and S. obtusirostris were decided to breed separately. Parental fishes were separated phenotypicaly on the basis of the morphological signs. PCR-RFLP analysis of the exon 3 to exon 4 part of the lactate dehydrogenase (LDH C1* gene with restriction endonuclease RsaI was employed to identify the presence of other species representatives or intercrosses in two groups of juvenille fishes. Using this method, we were able to identify two S. trutta representatives in the S. obtusirostris group.

  16. Environmental impacts of genetic improvement in growth rate and feed conversion in fish farming under density and nitrogen limitation

    NARCIS (Netherlands)

    Besson, M.; Aubin, J.; Arendonk, van J.A.M.; Komen, H.; Poelman, M.; Quillet, E.; Vandeputte, M.; Boer, de I.J.M.

    2014-01-01

    Many environmental impacts can be attributed to fish farming and there is a need to explore new ways of reducing environmental impacts, such as fish genetic improvement. The environmental consequences of genetic improvement in thermal growth coefficient (TGC) and in feed conversion ratio (FCR) were

  17. Environmental impacts of genetic improvement of growth rate and feed conversion ratio in fish farming under rearing density and nitrogen output limitations

    NARCIS (Netherlands)

    Besson, M.; Aubin, J.; Komen, H.; Poelman, M.; Quillet, E.; Vandeputte, M.; Arendonk, Van J.A.M.; Boer, De I.J.M.

    2016-01-01

    Today, fish farming faces an increasing demand in fish products, but also various environmental challenges. Genetic improvement in growth rate and feed conversion ratio is known to be an efficient way to increase production and increase efficiency in fish farming. The environmental consequences

  18. Life Cycle Assessment of Gilthead Seabream (Sparus aurata Production in Offshore Fish Farms

    Directory of Open Access Journals (Sweden)

    Benjamín García García

    2016-11-01

    Full Text Available Life cycle assessment is used in this study to evaluate the potential environmental impacts of producing gilthead seabream in an offshore sea farm exposed to storms in the Spanish Mediterranean Sea. The farming methods used can be considered as “basic” since no centralized or automatic food distribution system exists and there is no control system. This study aims to identify the main hotspots under these conditions and to propose and compare viable alternatives to them. Contribution analysis found that the component of the system with the greatest potential environmental impact (48% of the overall impact was fish feed, especially the raw material used. Other contributory factors were the fuel consumed by the vessels operating in the farm (35%, the dumping of N and P in the environment due to the metabolism of the fish (12%, the cages and their anchorage system (5%. A sensitivity analysis showed that a significant reduction in potential environmental impact can be achieved by increasing feeding efficiency. Feed formulation in raw materials is also an important factor and could serve to diminish overall adverse effects. A balance needs to be found between productive performance (growth, survival and feed conversion rate, feed price and its influence on production costs and the overall environmental consequences.

  19. Phytoremediation Capabilities of Spirodela polyrhiza and Salvinia molesta in Fish Farm Wastewater: A Preliminary Study

    Science.gov (United States)

    Ng, Y. S.; Samsudin, N. I. S.; Chan, D. J. C.

    2017-06-01

    Fish farm wastewater needs to be treated as it contains considerably high loading of suspended solids and dissolved nutrients from accumulation of by-products e.g. fish excretions and uneaten feed. In this study, macrophytes, namely Spirodela polyrhiza and Salvinia molesta were examined for their phytoremediation efficiency in treating fish farm wastewater in a raceway pond rig. It was carried out indoor for 14 days under controlled environment. Water samples was collected once every 2 days for analysis of NO3 -- N, PO4 3-, NH3-N, COD, turbidity, MLVSS and pH. The results showed that there was decrement of phosphate in fish farm wastewater using either S. polyrhiza or S. molesta. Interestingly, S. polyrhiza was found to be more efficient in phosphate uptake as it removed 72% phosphate at day 4 and up to 95% in the end of the experiment whereas 72% phosphate removal was only achieved by S. molesta at day 10. Similar ammonia decrement was observed for both plants and most of the ammonia were not detected in the wastewater by day 10 for S. polyrhiza, while by day 8 for S. molesta. Nitrate showed increment for both plants which could be due to nitrification. Both plants achieved highest COD removal on day 12, whereby 68% for S. polyrhiza and 63% for S. molesta. They were able to reduce turbidity and total suspended solids (TSS) to very low level and significantly increase clarity of wastewater. S. polyrhiza reduced up to 96% of initial turbidity value and 86% of TSS. 82% reduction of initial turbidity and 79% TSS decrement were observed for S. molesta. pH fluctuations were minimum for both plants, with a range between 7.62 to 7.77. Both plants demonstrated biomass increment for fresh weight in which 84% for S. polyrhiza while 85% for S. molesta. This study proved that the macrophytes were able to treat fish farm wastewater by significantly removing phosphate, ammonia, turbidity and TSS. It aids in minimizing pollutants released to receiving waters and producing biomass

  20. Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming.

    Science.gov (United States)

    Besson, M; de Boer, I J M; Vandeputte, M; van Arendonk, J A M; Quillet, E; Komen, H; Aubin, J

    2017-01-01

    In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA) to calculate the economic (EV) and environmental (ENV) values of thermal growth coefficient (TGC) and feed conversion ratio (FCR) of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod), annual feed distributed (Qannual_feed), standing stock (Qstock), and daily feed distributed (Qdaily_feed). ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish)) and per farm per year (ENV(farm)). Results show that irrespective of quota used, EV of FCR as well as ENV(fish) and ENV(farm) were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish) of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm) of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR.

  1. Fish farming of native species in Colombia: current situation and perspectives

    DEFF Research Database (Denmark)

    Cruz-Casallas, P. E.; Medina-Robles, V. M.; Velasco-Santamaria, Y. M.

    2011-01-01

    In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities. The Colom......In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities...... Prochilodus magdalenae (Steindachner), carp Cyprinus carpio (Linnaeus) and yamu Brycon amazonicus (Spix & Agassiz). From the three main fish species, cachama blanca is the only native species, which has shown excellent performance in pond farming due to its rusticity, omnivorous habits, docility, meat quality......, food conversion and disease resistance. The limited offer of Colombian fish farmed species determines its currently low competitiveness and restricted impact on the international markets; thus making necessary to explore the potential of new fish species in order to introduce them to the pisciculture...

  2. Risk formulation for the sonic effects of offshore wind farms on fish in the EU region.

    Science.gov (United States)

    Kikuchi, Ryunosuke

    2010-02-01

    In 2007, European leaders agreed to source 20% of their energy needs from renewable energy; since that time, offshore wind farms have been receiving attention in the European Union (EU). In 2008, the European Community submitted a proposal to the United Nations Environment Program (UNEP) in order to combat marine noise pollution. In consideration of these facts, the present paper aims to deduce a preliminary hypothesis and its formulation for the effect of offshore wind farm noise on fish. The following general picture is drawn: the short-term potential impact during pre-construction; the short-term intensive impact during construction; and the physiological and/or masking effects that may occur over a long period while the wind farm is in operation. The EU's proposal to UNEP includes noise databases that list the origins of man-made sounds; it is advisable that offshore wind farms should be listed in the noise databases in order to promote rational environment management. Copyright 2009 Elsevier Ltd. All rights reserved.

  3. Fish survey, fishing duration and other data from net trawls and other gear from the COMMANDO as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 31 March 1978 to 19 March 1979 (NODC Accession 8100690)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls and other gear from the COMMANDO from 31 March 1978 to 19 March 1979. Data were...

  4. Fish survey, fishing duration, and other data from net trawls from the NORTH PACIFIC as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 25 April 1975 to 07 August 1975 (NODC Accession 7601822)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from the NORTH PACIFIC from 25 April 1975 to 07 August 1975. Data were collected by the...

  5. Fish survey, fishing duration, and other data from net trawls in the Gulf of Alaska from the NORTH PACIFIC as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 03 May 1975 to 07 August 1975 (NODC Accession 7601886)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Gulf of Alaska from the NORTH PACIFIC from 03 May 1975 to 07 August 1975. Data...

  6. Fish survey, fishing duration, and other data from net trawls from the BARGE and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 16 June 1976 to 30 March 1977 (NODC Accession 7800030)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from the BARGE and other platforms from 16 June 1976 to 30 March 1977. Data were...

  7. Fish survey, fishing duration, and other data from net trawls in the Gulf of Alaska from the NORTH PACIFIC as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 03 May 1975 to 07 August 1975 (NODC Accession 7601885)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Gulf of Alaska from the NORTH PACIFIC from 03 May 1975 to 07 August 1975. Data...

  8. Fish survey, fishing duration, and other data from net and otter trawls from the BIG VALLEY as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 20 May 1976 to 30 June 1976 (NODC Accession 7601547)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net and otter trawls from the BIG VALLEY from 20 May 1976 to 30 June 1976. Data were collected by...

  9. Fish survey, fishing duration, and other data from net trawls from the BARGE as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 24 June 1976 to 10 September 1976 (NODC Accession 7800146)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from the BARGE from 24 June 1976 to 10 September 1976. Data were collected by the...

  10. Fish survey, fishing duration and other data from net trawls from the SEA STAR as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 29 April 1976 to 24 August 1976 (NODC Accession 7800273)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from the SEA STAR from 29 April 1976 to 24 August 1976. Data were collected by Dames and...

  11. Fish survey, fishing duration, and other data from net trawls from the BARGE and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 30 May 1977 to 13 October 1977 (NODC Accession 7800268)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from the BARGE and other platforms from 30 May 1977 to 13 October 1977. Data were...

  12. Fish welfare assurance system: initial steps to set up an effective tool to safeguard and monitor farmed fish welfare at a company level.

    Science.gov (United States)

    van de Vis, J W; Poelman, M; Lambooij, E; Bégout, M-L; Pilarczyk, M

    2012-02-01

    The objective was to take a first step in the development of a process-oriented quality assurance (QA) system for monitoring and safeguarding of fish welfare at a company level. A process-oriented approach is focused on preventing hazards and involves establishment of critical steps in a process that requires careful control. The seven principles of the Hazard Analysis Critical Control Points (HACCP) concept were used as a framework to establish the QA system. HACCP is an internationally agreed approach for management of food safety, which was adapted for the purpose of safeguarding and monitoring the welfare of farmed fish. As the main focus of this QA system is farmed fish welfare assurance at a company level, it was named Fish Welfare Assurance System (FWAS). In this paper we present the initial steps of setting up FWAS for on growing of sea bass (Dicentrarchus labrax), carp (Cyprinus carpio) and European eel (Anguilla anguilla). Four major hazards were selected, which were fish species dependent. Critical Control Points (CCPs) that need to be controlled to minimize or avoid the four hazards are presented. For FWAS, monitoring of CCPs at a farm level is essential. For monitoring purposes, Operational Welfare Indicators (OWIs) are needed to establish whether critical biotic, abiotic, managerial and environmental factors are controlled. For the OWIs we present critical limits/target values. A critical limit is the maximum or minimum value to which a factor must be controlled at a critical control point to prevent, eliminate or reduce a hazard to an acceptable level. For managerial factors target levels are more appropriate than critical limits. Regarding the international trade of farmed fish products, we propose that FWAS needs to be standardized in aquaculture chains. For this standardization a consensus on the concept of fish welfare, methods to assess welfare objectively and knowledge on the needs of farmed fish are required.

  13. Eating fish and farm life reduce allergic rhinitis at the age of twelve.

    Science.gov (United States)

    Vasileiadou, Styliana; Wennergren, Göran; Strömberg Celind, Frida; Åberg, Nils; Pettersson, Rolf; Alm, Bernt; Goksör, Emma

    2018-02-15

    The prevalence of allergic rhinitis has increased, but the cause of this rise is partly unknown. Our aim was to analyse the prevalence, risk factors and protective factors for allergic rhinitis in 12-year-old Swedish children. Data were collected from a prospective, longitudinal cohort study of children born in western Sweden in 2003. The parents answered questionnaires when the children were six months to 12 years. The response rate at 12 years was 76% (3,637/4,777) of the questionnaires distributed. The prevalence of allergic rhinitis at 12 years was 22% and 57% were boys. Mean age at onset was 7.8 years and 55% reported their first symptoms after eight years. The most common trigger factors were pollen (85%), furry animals (34%) and mites (17%). A multivariate analysis showed that the adjusted odds ratios and 95% confidence intervals for the independent risk factors for allergic rhinitis at 12 were: parental allergic rhinitis (2.32, 1.94-2.77), doctor-diagnosed food allergy in the first year (1.75, 1.21-2.52), eczema in the first year (1.61, 1.31-1.97) and male gender (1.25, 1.06-1.47). Eating fish once a month or more at age 12 months reduced the risk of allergic rhinitis at 12 years (0.70, 0.50-0.98) as did living on a farm with farm animals at four years (0.51, 0.32-0.84). Continuous farm living from age 4 to 12 seemed to drive the association. Allergic rhinitis affected more than 20% of 12-year-olds, but was lower in children who ate fish at 12 months or grew up with farm animals. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. Appearance traits in fish farming: progress from classical genetics to genomics, providing insight into current and potential genetic improvement

    Science.gov (United States)

    Colihueque, Nelson; Araneda, Cristian

    2014-01-01

    Appearance traits in fish, those external body characteristics that influence consumer acceptance at point of sale, have come to the forefront of commercial fish farming, as culture profitability is closely linked to management of these traits. Appearance traits comprise mainly body shape and skin pigmentation. Analysis of the genetic basis of these traits in different fish reveals significant genetic variation within populations, indicating potential for their genetic improvement. Work into ascertaining the minor or major genes underlying appearance traits for commercial fish is emerging, with substantial progress in model fish in terms of identifying genes that control body shape and skin colors. In this review, we describe research progress to date, especially with regard to commercial fish, and discuss genomic findings in model fish in order to better address the genetic basis of the traits. Given that appearance traits are important in commercial fish, the genomic information related to this issue promises to accelerate the selection process in coming years. PMID:25140172

  15. Appearance traits in fish farming: progress from classical genetics to genomics, providing insight into current and potential genetic improvement

    Directory of Open Access Journals (Sweden)

    Nelson eColihueque

    2014-08-01

    Full Text Available Appearance traits in fish, those external body characteristics that influence consumer acceptance at point of sale, have come to the forefront of commercial fish farming, as culture profitability is closely linked to management of these traits. Appearance traits comprise mainly body shape and skin pigmentation. Analysis of the genetic basis of these traits in different fish reveals significant genetic variation within populations, indicating potential for their genetic improvement. Work into ascertaining the minor or major genes underlying appearance traits for commercial fish is emerging, with substantial progress in model fish in terms of identifying genes that control body shape and skin colors. In this review, we describe research progress to date, especially with regard to commercial fish, and discuss genomic findings in model fish in order to better address the genetic basis of the traits. Given that appearance traits are important in commercial fish, the genomic information related to this issue promises to accelerate the selection process in coming years.

  16. Preliminary aspects concerning phytoplankton structure in the Balta Mare – Carja 1 fish farm

    Directory of Open Access Journals (Sweden)

    Maria FETECAU

    2010-08-01

    Full Text Available The present paper presents information on the structure and the dynamics of the water ecosystem’s phytoplankton of the Carja 1 fish farm - Vaslui County, carps and Asian cyprinids are grown ascommon fish. To establish the structure and the dynamics of the phytoplankton, two samples from 6 stations were taken in the spring and in the autumn, using of a Garmin GPS 7- type navigation system.When analysing the number of individuals and the algae species present in the phytoplankton’s structure, one can notice the low development level of the vegetable plankton. From the quantity point of view, one can notice the numerical abundance of the clorophyceae in all the analysed samples. The dominant species were: Scenedesmus acuminatus, Scenedesmus quadricauda, Tetrastrum staurogenieforme. The small number of species and algae specimens determined in the phytoplankton’s structure emphasizes the reduced level of trophicity and biodiversity of the analysed ecosystem.

  17. Spatiotemporal Dispersal and Deposition of Fish Farm Wastes: A Model Study from Central Norway

    Directory of Open Access Journals (Sweden)

    Ole J. Broch

    2017-06-01

    Full Text Available A spatially explicit coupled hydrodynamic-mass transport model system was used to simulate dispersal of particulate organic matter from Atlantic salmon (Salmo salar farming in central Norway. Model setups of 32 m horizontal resolution were run for periods of up to 650 days for 3 sites of different oceanographic characteristics: one fjord location, one medium-exposed location influenced by fjord water, and one coastal location. Records on feed used for each cage at each location were converted to feces released based on a published mass balance model. The results from the simulations were compared with scores from corresponding mandatory benthic surveys (MOM-B of the sediment layer beneath the farms. The correspondence between simulated and measured thickness of the sediment layer was good, and improved with the inclusion of resuspension processes. At all sites the distribution of organic matter in the bottom layer was non-homogeneous, with significant temporal variation and transport and settling of matter up to at least 0.5 km away from one of the farms. Our results indicate that the monitoring practice used in Norway until now, with a few sediment grab samples taken mainly within the fish farm, may not adequately determine the areal impacts of all salmon farming operations. The patchy distribution of organic matter and the correspondence between simulation and survey results is attributed to the use of full 3D current fields of a high spatiotemporal resolution and a good model for resuspension processes that some previous model studies have failed to properly account for.

  18. Waste feed from coastal fish farms: A trophic subsidy with compositional side-effects for wild gadoids

    Science.gov (United States)

    Fernandez-Jover, Damian; Martinez-Rubio, Laura; Sanchez-Jerez, Pablo; Bayle-Sempere, Just T.; Lopez Jimenez, Jose Angel; Martínez Lopez, Francisco Javier; Bjørn, Pål-Arne; Uglem, Ingebrigt; Dempster, Tim

    2011-03-01

    Aquaculture of carnivorous fish species in sea-cages typically uses artificial feeds, with a proportion of these feeds lost to the surrounding environment. This lost resource may provide a trophic subsidy to wild fish in the vicinity of fish farms, yet the physiological consequences of the consumption of waste feed by wild fish remain unclear. In two regions in Norway with intensive aquaculture, we tested whether wild saithe ( Pollachius virens) and Atlantic cod ( Gadus morhua) associated with fish farms (F assoc), where waste feed is readily available, had modified diets, condition and fatty acid (FA) compositions in their muscle and liver tissues compared to fish unassociated (UA) with farms. Stomach content analyses revealed that both cod and saithe consumed waste feed in the vicinity of farms (6-96% of their diet was composed of food pellets). This translated into elevated body and liver condition compared to fish caught distant from farms for cod at both locations and elevated body condition for saithe at one of the locations. As a consequence of a modified diet, we detected significantly increased concentrations of terrestrial-derived fatty acids (FAs) such as linoleic (18:2ω6) and oleic (18:1ω9) acids and decreased concentrations of DHA (22:6ω3) in the muscle and/or liver of F assoc cod and saithe when compared with UA fish. In addition, the ω3:ω6 ratio clearly differed between F assoc and UA fish. Linear discriminant analysis (LDA) correctly classified 97% of fish into F assoc or UA origin for both cod and saithe based on the FA composition of liver tissues, and 89% of cod and 86% of saithe into F assoc or UA origin based on the FA composition of muscle. Thus, LDA appears a useful tool for detecting the influence of fish farms on the FA composition of wild fish. Ready availability of waste feed with high protein and fat content provides a clear trophic subsidy to wild fish in coastal waters, yet whether the accompanying side-effect of altered fatty

  19. Metals concentrations in Nile tilapia Oreochromis niloticus () from illegal fish farm in Al-Minufiya Province, Egypt, and their effects on some tissues structures.

    Science.gov (United States)

    Authman, Mohammad M N; Abbas, Wafaa T; Gaafar, Alkhateib Y

    2012-10-01

    This study clarified the suitability of fishes caught from illegal fish farms to human consumption and their hazards to public health. For this purpose, the concentrations of some metals (Al, Cd, Pb, Hg and Ni) in water and Nile tilapia (Oreochromis niloticus) fish samples collected from an illegal fish farm, in addition to pathological conditions of the fish tissues, were examined. The illegal farm water was found to be heavily polluted with metals which far exceeded the permissible limits. It was found that metals accumulated in tissues of O. niloticus in concentrations higher than those of farm water. Kidney of O. niloticus contained the highest concentrations of the detected metals, while muscle and skin contained the lowest concentrations. The examination of fish tissues revealed various histopathological lesions which related directly to the pollution of the illegal farm water. Moreover, metals levels in O. niloticus muscle were higher than the maximum permissible levels for human consumption. Consequently, the flesh of fishes from the illegal farms could be considered hazardous to human health. Therefore, warning against eating fish caught from the illegal fish farms should be announced. Moreover, removal of such illegal fish farms is necessary for the public health protection. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Expert consultation on risk factors for introduction of infectious pathogens into fish farms.

    Science.gov (United States)

    Oidtmann, Birgit C; Peeler, Edmund J; Thrush, Mark A; Cameron, Angus R; Reese, R Allan; Pearce, Fiona M; Dunn, Peter; Lyngstad, Trude M; Tavornpanich, Saraya; Brun, Edgar; Stärk, Katharina D C

    2014-08-01

    An expert consultation was conducted to provide quantitative parameters required to inform risk-based surveillance of aquaculture holdings for selected infectious hazards. The hazards were four fish diseases endemic in some or several European countries: infectious salmon anaemia (ISA), viral haemorrhagic septicaemia (VHS), infectious haematopoietic necrosis (IHN), and koi herpes virus disease (KHD). Experts were asked to provide estimates for the relative importance of 5 risk themes for the hazard to be introduced into and infect susceptible fish at the destination. The 5 risk themes were: (1) live fish and egg movements; (2) exposure via water; (3) on-site processing; (4) short distance mechanical transmission and (5) distance independent mechanical transmission. The experts also provided parameter estimates for hazard transmission pathways within the themes. The expert consultation was undertaken in a 2 step approach: an online survey followed by an expert consultation meeting. The expert opinion indicated that live fish movements and exposure via water were the major relevant risk themes. Experts were recruited from several European countries and thus covered a range of farming systems. Therefore, the outputs from the expert consultation have relevance for the European context. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  1. Changes in fish communities on a small spatial scale, an effect of increased habitat complexity by an offshore wind farm.

    Science.gov (United States)

    van Hal, R; Griffioen, A B; van Keeken, O A

    2017-05-01

    The number of offshore wind farms (OWF) is increasing to meet the demands for renewable energy. The piles and hard substrate surrounding these piles creates new habitat for species with preference to hard substrates. We studied the impact of this hard substrate on the fish community in a Dutch OWF in the sandy southern North Sea, which had been in operation for five years. Multi-mesh gillnets were placed near the OWF structures on the hard substrate protection revetments and on the sandy bottom in the middle of the farm. The catches indicated attraction of cod, pouting, bullrout and edible and velvet crab, while attraction to the sandy habitat was shown for flatfish and whiting. Further, two species previously not caught in this area, goldsinny wrasse and grey trigger fish, were caught on the hard substrate. In addition a Dual-Frequency Identification Sonar (DIDSON) was used to record transects through the farm to observe individual fish in the water column throughout the farm and very near the OWF structures. High abundances of fish near the structure were observed during some days, while during other days equal distribution of fish in the area was observed. The area around the structures is thus only used temporarily for shelter or feeding. The DIDSON also allowed looking at the aggregation level of the fish. Seasonally the aggregation level differed most likely due to different species occurring in the area. In April, most fish were aggregated in schools, while in summer most observations were individual fish or loose aggregations. The wind farm structures had limited effect on the aggregation level compared to season or weather conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Impacts of fish farm pollution on ecosystem structure and function of tropical headwater streams.

    Science.gov (United States)

    Rosa, Rodrigo dos Santos; Aguiar, Anna Carolina Fornero; Boëchat, Iola Gonçalves; Gücker, Björn

    2013-03-01

    We investigated the impacts of effluent discharge from small flow-through fish farms on stream water characteristics, the benthic invertebrate community, whole-system nitrate uptake, and ecosystem metabolism of three tropical headwater streams in southeastern Brazil. Effluents were moderately, i.e. up to 20-fold enriched in particulate organic matter (POM) and inorganic nutrients in comparison to stream water at reference sites. Due to high dilution with stream water, effluent discharge resulted in up to 2.0-fold increases in stream water POM and up to 1.8-fold increases in inorganic nutrients only. Moderate impacts on the benthic invertebrate community were detected at one stream only. There was no consistent pattern of effluent impact on whole-stream nitrate uptake. Ecosystem metabolism, however, was clearly affected by effluent discharge. Stream reaches impacted by effluents exhibited significantly increased community respiration and primary productivity, stressing the importance of ecologically sound best management practices for small fish farms in the tropics. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Treatment of freshwater fish farm effluent using constructed wetlands: the role of plants and substrate.

    Science.gov (United States)

    Naylor, S; Brlsson, J; Labelle, M A; Drizo, A; Comeau, Y

    2003-01-01

    Freshwater fish farm effluents have low nutrient concentrations but high flow rates, resulting in pollutant load, especially phosphorus (P), causing eutrophication. The feasibility was tested of a treatment combining, within a single constructed wetland, the contribution of macrophytes for reducing organic matter and nitrogen (N), with the high efficiency of steel slag and limestone for P removal. Twenty subsurface flow (SSF) basins of 280 L with different combinations of plants (Phragmites communis or Typha latifolia) and substrates (steel slag, limestone, gravel, peat) were fed with a reconstituted fish farm effluent in a greenhouse experiment. Pollutant removal was generally very good under all treatments. N and organic matter removal were correlated with plant biomass while P removal was better in substrates with steel slag and limestone. However, the high pH of the P-adsorbing substrate was detrimental to plant growth so that no combination of plants and substrates could maximise in one step the simultaneous removal of all evaluated pollutants. Therefore, the use of two sequential units is recommended, a first one consisting of a macrophyte planted basin using a neutral substrate to remove organic matter and N, followed by a second unplanted basin containing only a P-adsorbing substrate.

  4. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Directory of Open Access Journals (Sweden)

    Monika Manthey-Karl

    2016-08-01

    Full Text Available To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus and barramundi (Lates calcarifer and of farmed pangasius (Pangasianodon hypophthalmus. The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1 were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable.

  5. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Science.gov (United States)

    Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

    2016-01-01

    To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable. PMID:28231154

  6. Molecular confirmation of infectious spleen and kidney necrosis virus (ISKNV) in farmed and imported ornamental fish in Australia.

    Science.gov (United States)

    Mohr, Peter G; Moody, Nicholas J G; Williams, Lynette M; Hoad, John; Cummins, David M; Davies, Kelly R; StJ Crane, Mark

    2015-10-16

    Viruses of the genus Megalocytivirus have not been detected in wild populations of fish in Australia but circulate in imported ornamental fish. In 2012, detection of a megalocytivirus in healthy platys Xiphophorus maculatus was reported from a farm in Australia during surveillance testing as part of a research project undertaken at the University of Sydney. Confirmatory testing of the original samples at the AAHL Fish Diseases Laboratory verified the presence of an infectious spleen and kidney necrosis virus (ISKNV)-like virus. Additional sampling at the positive farm confirmed the persistence of the virus in the platys, with 39 of 265 (14.7%) samples testing positive. Comparison of 3 separate gene regions of the virus with those of ISKNV confirmed the detection of a virus indistinguishable from ISKNV. Subsequently, ISKNV was also detected in a range of imported ornamental fish from several countries between 2013 and 2014, by screening with real-time PCR and confirmation by conventional PCR and sequence analysis. Accordingly, the current importation of live ornamental fish acts as a potential perpetual source for the establishment of ISKNV viruses within Australia. The testing of the farmed and imported ornamental fish verified the utility of the probe-based real-time PCR assay for screening of ornamental fish for Megalocytivirus.

  7. Population structure and recruitment of the ectoparasite Argulus coregoni Thorell (Crustacea: Branchiura) on a fish farm.

    Science.gov (United States)

    Hakalahti, T; Valtonen, E T

    2003-07-01

    The population structure and recruitment of Argulus coregoni was monitored at a Finnish fish farm during the open water periods of 1999 and 2001 by weekly sampling of attached argulids. In 2001 the numbers of rainbow trout examined increased in the autumn when the A. coregoni population was declining. When the water temperature exceeded 10 degrees C, at the end of May, A. coregoni egg hatching commenced. A mean number of 98 (S.D. +/- 5.4) juvenile A. coregoni was recorded on each fish, before the start of female egg laying in July 1999. The abundance of lice was lower in 2001. The main recruitment of A. coregoni juveniles occurred in early summer, but the hatching of eggs continued until September. However, no pulses of hatching were recorded later in the summer and the numbers of lice on fish substantially decreased after mid-July in both years. On average, only 0.6 (S.D. +/- 0.72) parasites/fish were found between August and late October 2001 and none in November. We suggest that there is 1 main A. coregoni generation annually in Central Finland. Environmental conditions, especially temperature, affects the population cycle of A. coregoni: we found a more synchronous and intense population cycle during the summer 1999, when the early summer was warmer than in 2001. The overall sex ratio (female:male) of A. coregoni was nearly 1:1 in June 1999, but was male biased (1:1.4) in June 2001. It was also shown that from July onwards, many females detached from the fish host in order to lay their eggs on the bottom of the pond. Large males were often bigger than the largest females between mid-July and early September 2001, when as many as 3.7 (s.r. +/- 1.48) times more males than females were present in the lice samples.

  8. Development of a new multiple sampling trawl with autonomous opening/closing net control system for sampling juvenile pelagic fish

    Science.gov (United States)

    Oozeki, Yoshioki; Hu, Fuxiang; Tomatsu, Chiaki; Kubota, Hiroshi

    2012-03-01

    A new multiple layer sampling trawl with an autonomous net opening/closing control system was developed to sample pelagic juvenile fish quantitatively. The new trawl system, based on the Matsuda-Oozeki-Hu Trawl (MOHT), has a rigid-frame 3.3 m high and 2.35 m wide and five nets of 11.0 m length with a rectangular mouth of 2.22 m×1.81 m (4 m2 mouth area; large-scale prototype). A cambered V-shape depressor is hung below the frame and two bridles are attached at the midpoint of the side frames. A net-release controller is used, which not only controls the net release mechanism but also records the net depth, temperature and flow rate during net towing. The controller sends stored command signals to the net release mechanism as depth settings and/or time settings and does not require any commands from the surface through a conducting cable or by acoustic signals. Two other models were constructed before the construction of the large-scale prototype, which are a small-scale prototype (2 m2 mouth area) for testing the net release mechanism and a 1/4-scale model of the large-scale prototype for flume tank tests. Flume tank tests with the 1/4-scale model showed that the frame leaned forward at a tilt angle from 5 to 15 degrees at towing speeds from 0.8 to 1.4 m s-1. Opened nets closed smoothly and sequentially nets were completely opened when the trigger was released by the command. Net depth rarely changed even during changes in towing speed. Sea trials both by the small-scale and the large-scale prototype demonstrated the same towing characteristics expected from the flume tank tests. The newly developed multiple layer opening/closing MOHT (MOC-MOHT) is considered to be suitable for quantitative layer sampling of juvenile fish.

  9. A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described...... by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing...

  10. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus)

    NARCIS (Netherlands)

    Besson, M.; Komen, H.; Aubin, J.; Boer, de I.J.M.; Poelman, M.; Quillet, E.; Vancoillie, C.; Vandeputte, M.; Arendonk, van J.A.M.

    2014-01-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal

  11. Relationship between sedimentation rates and benthic impact on Maërl beds derived from fish farming in the Mediterranean.

    Science.gov (United States)

    Sanz-Lázaro, Carlos; Belando, María Dolores; Marín-Guirao, Lázaro; Navarrete-Mier, Francisco; Marín, Arnaldo

    2011-02-01

    The aim of this work was to study the dispersion of particulate wastes derived from marine fish farming and correlate the data with the impact on the seabed. Carbon and nutrients were correlated with the physico-chemical parameters of the sediment and the benthic community structure. The sedimentation rates in the benthic system were 1.09, 0.09 and 0.13 g m⁻² day⁻¹ for particulate organic carbon (POC), particulate organic nitrogen (PON) and total phosphorus (TP), respectively. TP was a reliable parameter for establishing the spatial extent of the fish farm particulate wastes. Fish farming was seen to influence not only physico-chemical and biological parameters but also the functioning of the ecosystem from a trophic point of view, particularly affecting the grazers and the balance among the trophic groups. POC, PON and TP sedimentation dynamics reflected the physico-chemical status of the sediment along the distance gradient studied, while their impact on the benthic community extended further. Therefore, the level of fish farm impact on the benthic community might be underestimated if it is assessed by merely taking into account data obtained from waste dispersion rates. The benthic habitat beneath the fish farm, Maërl bed, was seen to be very sensitive to aquaculture impact compared with other unvegetated benthic habitats, with an estimated POC-carrying capacity to maintain current diversity of 0.087 g C m⁻² day⁻¹ (only 36% greater than the basal POC input). Environmental protection agencies should define different aquaculture waste load thresholds for different benthic communities affected by finfish farming, according to their particular degree of sensitivity, in order to maintain natural ecosystem functions. © 2010 Elsevier Ltd. All rights reserved.

  12. The effect of twine thickness on the size selectivity and fishing power of Baltic cod gill nets

    DEFF Research Database (Denmark)

    Holst, René; Wileman, D.; Madsen, Niels

    2002-01-01

    . Subsequently a model was fitted for the mean selectivity taking between-set variation into account. The selectivity Curve that fitted the data best was given by the sum of two normal distributions. It was found that twine thickness and trials period had relatively little effect upon the shape......Sea trials were carried out on a Danish commercial vessel measuring the size selectivity and fishing power of gill nets used to catch Baltic cod (Gadus morhua). A comparison was made of two different twine thicknesses at two different times of the year. Nominal mesh sizes of 70-130 mm were used....... Method of capture, condition factor and girths were measured for sub- samples of the cod caught. A model of the size selectivity of the gill nets was adapted to the experimental conditions where two gears were fished on the same population. This model was fitted to the catch data for each set...

  13. Modelling the fate of pesticides in paddy rice-fish pond farming system in Northern Vietnam

    Science.gov (United States)

    Lamers, M.; Nguyen, N.; Streck, T.

    2012-04-01

    During the last decade rice production in Vietnam has tremendously increased due to the introduction of new high yield, short duration rice varieties and an increased application of pesticides. Since pesticides are toxic by design, there is a natural concern on the possible impacts of their presence in the environment on human health and environment quality. In North Vietnam, lowland and upland rice fields were identified to be a major non-point source of agrochemical pollution to surface and ground water, which are often directly used for domestic purposes. Field measurements, however, are time consuming, costly and logistical demanding. Hence, quantification, forecast and risk assessment studies are hampered by a limited amount of field data. One potential way to cope with this shortcoming is the use of process-based models. In the present study we developed a model for simulating short-term pesticide dynamics in combined paddy rice field - fish pond farming systems under the specific environmental conditions of south-east Asia. Basic approaches and algorithms to describe the key underlying biogeochemical processes were mainly adopted from the literature to assure that the model reflects the current standard of scientific knowledge and commonly accepted theoretical background. The model was calibrated by means of the Gauss-Marquardt-Levenberg algorithm and validated against measured pesticide concentrations (dimethoate and fenitrothion) during spring and summer rice crop season 2008, respectively, of a paddy field - fish pond system typical for northern Vietnam. First simulation results indicate that our model is capable to simulate the fate of pesticides in such paddy - fish pond farming systems. The model efficiency for the period of calibration, for example, was 0.97 and 0.95 for dimethoate and fenitrothion, respectively. For the period of validation, however, the modeling efficiency slightly decreased to 0.96 and 0.81 for dimethoate and fenitrothion

  14. A comparison of methane emissions following rice paddies conversion to crab-fish farming wetlands in southeast China.

    Science.gov (United States)

    Hu, Zhiqiang; Wu, Shuang; Ji, Cheng; Zou, Jianwen; Zhou, Quansuo; Liu, Shuwei

    2016-01-01

    Rice paddies and aquaculture wetlands are typical agricultural wetlands that constitute one of the important sources of atmospheric methane (CH4). Traditional transplanted rice paddies have been experiencing conversion to pond aquaculture wetlands for pursuing higher economic benefits over the past decades in southeast China. A parallel field experiment was carried out to compare CH4 emissions from a transplanted rice paddy and its converted crab-fish farming wetland in southeast China. Over the rice-growing season, CH4 fluxes averaged 1.86 mg m(-2) h(-1) from rice paddies, and 1.14 and 0.50 mg m(-2) h(-1) for the treatments with or without aquatic vegetation present in the crab-fish farming wetlands, respectively. When averaged across the treatments, seasonal CH4 emissions from crab-fish framing wetlands were 52% lower than those from rice paddies. The CH4 fluxes were negatively related to water dissolved oxygen (DO) concentration but positively related to soil/sediment dissolved organic carbon (DOC) content in crab-fish farming wetlands. Dependence of CH4 fluxes on DO or DOC was intensified by the aquatic vegetation presence. By extrapolating the present CH4 emission rate with the current rice paddy-converted aquaculture cultivation area, the seasonal CH4 emissions from inland aquaculture wetlands during the critical farming stage (20 June to 18 October) were estimated to be 33.6 Gg ha(-1) in southeast China in 2012. Rice paddies conversion to crab-fish farming wetlands might have reduced CH4 emissions by 22-54% in mainland China. Results of this study suggest that the conversion of transplanted rice paddies to crab-fish aquaculture wetlands for higher economic benefits would also lead to a lower ecosystem CH4 release rate.

  15. The dinoflagellates Pfiesteria shumwayae and Luciella masanensis cause fish kills in recirculation fish farms in Denmark

    DEFF Research Database (Denmark)

    Moestrup, Øjvind; Hansen, Gert; Daugbjerg, Niels

    2014-01-01

    Pfiesteriaceae. There were no other harmful algae present in either of the aquaculture plants. Serious fish kills in the US have been attributed to Pfiesteria during the past 20 years, but this type of mortality has not been documented elsewhere. L. masanensis, described recently from Korea and USA, has not been...... species was therefore based on molecular sequencing of nuclear-encoded LSU rDNA, confirmed by scanning electron microscopy and, eventually, also by examination of the very thin amphiesmal plates of the flagellates by calcofluor-stained cells in a fluorescence microscope.Although the two fish farms......, Tyrannodinium edax. Algal cells were observed to attach to their prey by an attachment filament and subsequently used a peduncle to suck up the food. Fish farms utilizing water recirculation technology are gaining popularity due to their reduced effect on the environment. The two cases from Denmark...

  16. Evaluation of chitosan application on agronomic parameters of tomato farming in shade net house conditions

    Directory of Open Access Journals (Sweden)

    María Caridad Jiménez Arteaga

    2015-03-01

    Full Text Available This research was done in net houses at Empresa de Servicios (ESUNI del Grupo Empresarial Cuba Níquel, in Moa municipality, Holguín. The objective was to evaluate the agronomic response of tomato cultivars to the application of chitosan, as an alternative to increase yield. Five doses of chitosan (250, 275, 300, 325, 350 mg/ha and control treatment were evaluated after transplantation. They were applied during the bloom stage in two moments, and an average of the both moments were obtained and their results were presented in tables and graphs. The main production indicators were evaluated. The two-way analysis of variance (ANOVA and the Tukey’s range test were used with p d” 0.05 and Statistica 8.0 software was used to perform the statistical analysis. According to the response of plants to the application of the polymer in the different evaluated variables of both experiments, it was confirmed that chitosan have the capacity to stimulate the processes

  17. Description age-3 brood rainbow trout bred in the conditions of the industral fish farm "Sloboda Banyliv"

    Directory of Open Access Journals (Sweden)

    P. Mendryshora

    2017-06-01

    Full Text Available Purpose. To analyze the results of cultivation and give fish-breeding and biological characteristics of age-3 brood rainbow trout grown using industrial technology in the conditions of the trout farm "Sloboda Banyliv." Methodology. Fish cultivation was carried in tank conditions of the trout farm "Sloboda Banyliv". The material for the study were age-3 brood rainbow trout obtained from eggs of the fall-spawning form of rainbow trout. Cultivation was carried out in a 216 m2 tank, stocking density of 255 fish/m2, using standard trout culture methods. Statistical analysis of the material was performed in Microsoft Office Excel (2003. Analysis of the variables was performed in the system of absolute values. The analysis criteria were their mean values mean deviations (M±m, standard error (σ, variability coefficient (Cv. Fish were fed with specialized feed manufactured by “BioMar” (Denmark with a high protein content (more than 40%. Findings. Based on the performed selective-breeding works aimed at creating brood stocks of rainbow trout, it was found that brood fish reared in the industrial conditions of the fish farm “Sloboda Banyliv”, despite instable culture conditions, were characterized by a moderate growth rate and had high values of productive and reproductive features. Mean weight of age-3 rainbow trout females was 1282.5 g, fecundity — 3.48 thousand eggs. Mean weight of produced eggs was 239.17 g, while individual parameters were 70.4 mg for the weight and 4.58 mm for the diameter. Originality. For the first time a study aimed at the formation of brood stocks of rainbow trout with analysis of phenotypic and productive features in the conditions of a fish farm with instable temperature and water regimes has been conducted. Practical value. The results of the performed work will allow selecting and forming a brood stock with high values of productive and reproductive features.

  18. Can energy willow (Salix sp.) remediate cadmium- and nickel-contaminated fish farm sludge?

    DEFF Research Database (Denmark)

    Pedersen, Marianne Bruus

    it meets the criteria. Phytoremediation by willow may combine accumulation of cadmium and nickel from the sludge with the production of an energy crop. The ability of eight selected willow clones to take up and tolerate cadmium and nickel was studied in pots under outdoor conditions. Fish farm sludge...

  19. Comparison of sulphate-reducing bacterial communities in Japanese fish farm sediments with different levels of organic enrichment.

    Science.gov (United States)

    Kondo, Ryuji; Mori, Yumi; Sakami, Tomoko

    2012-01-01

    Fish farm sediments receive a large amount of organic matter from uneaten food and fecal material. This nutrient enrichment, or organic pollution, causes the accumulation of sulphide in the sediment from the action of sulphate-reducing bacteria (SRB). We investigated the effect of organic enrichment around coastal fish farms comparing the SRB community structure in these sediments. Sediment samples with different levels of organic pollution classified based upon the contents of acid-volatile sulphide and chemical oxygen demand were collected at three stations on the coast of western Japan. The SRB community composition was assessed using PCR amplification, cloning, sequencing and phylogenetic analysis of the dissimilatory sulphite reductase b-subunit gene (dsrB) fragments using directly extracted sediment DNA. Sequencing of the cloned PCR products of dsrB showed the existence of different SRB groups in the sediments. The majority of dsrB sequences were associated with the families Desulfobacteraceae and Desulfobulbaceae. Clones related to the phylum Firmicutes were also detected from all sediment samples. Statistical comparison of sequences revealed that community compositions of SRB from polluted sediments significantly differed from those of moderately polluted sediments and unpolluted sediments (LIBSHUFF, p<0.05), showing a different distribution of SRB in the fish farm sediments. There is evidence showing that the organic enrichment of sediments influences the composition of SRB communities in sediments at marine fish farms.

  20. Nitrogen cycling and community structure of proteobacterial ß-subgroup ammonia-oxidizing bacteria within polluted marine fish farm sediments

    NARCIS (Netherlands)

    McCaig, A.E.; Phillips, C.B.; Stephen, J.R.; Kowalchuk, G.A.; Harvey, S.M.; Herbert, R.A.; Embley, T.M.; Prosser, J.I.

    1999-01-01

    A multidisciplinary approach was used to study the effects of pollution from a marine fish farm on nitrification rates and on the community structure of ammonia-oxidizing bacteria in the underlying sediment. Organic content, ammonium concentrations, nitrification rates, and ammonia oxidizer

  1. Fishing Nets between Two Seas: Guilds and Ship-Owner Associations in the Atlantic and Mediterranean Fishing Grounds of Andalusia

    Directory of Open Access Journals (Sweden)

    ISIDRO MAYA JARIEGO

    2016-01-01

    Full Text Available This study examines the organizational network of the extractive sector in Andalusian fishing enclaves. For this, we have evaluated 6 types of informal and institutional relationships between a total of 30 guilds and ship-owner associations in 21 Andalusian fi shing ports. The analyzed networks were found to have a core-periphery structure with the guilds playing a central role. The QAP procedure was used to identify two distinct contexts of relationship formation: informal meetings and the government fishing network (corresponding to formal meetings, such as fishing tables, port assemblies and fishing quota negotiations. We verified the existence of significant homophily dynamics based on both fishing ground and organization type.

  2. Net energy payback and CO2 emissions from three midwestern wind farms: An update

    Science.gov (United States)

    White, S.W.

    2006-01-01

    This paper updates a life-cycle net energy analysis and carbon dioxide emissions analysis of three Midwestern utility-scale wind systems. Both the Energy Payback Ratio (EPR) and CO2 analysis results provide useful data for policy discussions regarding an efficient and low-carbon energy mix. The EPR is the amount of electrical energy produced for the lifetime of the power plant divided by the total amount of energy required to procure and transport the materials, build, operate, and decommission the power plants. The CO2 analysis for each power plant was calculated from the life-cycle energy input data. A previous study also analyzed coal and nuclear fission power plants. At the time of that study, two of the three wind systems had less than a full year of generation data to project the life-cycle energy production. This study updates the analysis of three wind systems with an additional four to eight years of operating data. The EPR for the utility-scale wind systems ranges from a low of 11 for a two-turbine system in Wisconsin to 28 for a 143-turbine system in southwestern Minnesota. The EPR is 11 for coal, 25 for fission with gas centrifuge enriched uranium and 7 for gaseous diffusion enriched uranium. The normalized CO2 emissions, in tonnes of CO2 per GW eh, ranges from 14 to 33 for the wind systems, 974 for coal, and 10 and 34 for nuclear fission using gas centrifuge and gaseous diffusion enriched uranium, respectively. ?? Springer Science+Business Media, LLC 2007.

  3. First occurrence of Caprella scaura Templeton, 1836 (Crustacea: Amphipoda) on off-coast fish farm cages in the Mediterranean Sea

    Science.gov (United States)

    Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2014-03-01

    The non-indigenous caprellid Caprella scaura Templeton, 1836, native to the western Indian Ocean, was firstly recorded in the Mediterranean Sea in 1994, and all Mediterranean populations discovered to date are related to shoreline areas. A total of ten fish farms were sampled off the coasts of Spain (4), Italy (1), Croatia (2), Greece (1) and Malta (2). This is the first time that C. scaura has been reported from off-coast areas. Reproducing populations have been detected in fouling communities of three tuna farms off the coast of Croatia and Malta, which also signifies the first confirmed record of this species in both countries. The occurrence of successfully established and thriving populations of C. scaura Templeton, 1836 at floating off-coast fish farms underlines the importance of these structures as stepping stones in the species.

  4. Synthetic Musk fragrances in Trout from Danish fish farms and human milk

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Cederberg, Tommy Licht; Pedersen, K. H.

    2005-01-01

    and 2004 with a median concentration of 1.2 mu g/kg fresh weight (n.d.-28.0 mu g/kg fresh weight). It was also found that the concentration of musk xylene in trout sampled at the same fish farms decreased considerably from a median concentration of 5.1 mu g/kg fresh weight in 1992 to a median of 0.5 mu g....../HRMS in Danish farmed trout and human milk from primiparous mothers are reported. The polycyclic musk, HHCB, dominated the synthetic musk compounds found in trout samples from 1999 with a median concentration of 5.0 mu g/kg fresh weight (n.d.-52.6 mu g/kg fresh weight) and in trout samples collected in 2003....../kg fresh weight in 1999 and to a median less than the detection limit (0.23 mu g/kg fresh weight) in 2003. HHCB also dominated in Danish human milk samples collected in 1999 with a median concentration of 147 mu g/kg fat (38.0-422 mu g/kg fat). Human dietary intake assessment and body burden calculations...

  5. Total lipids and fatty acid profile in the liver of wild and farmed Catla catla fish

    Directory of Open Access Journals (Sweden)

    Hussain, Bilal

    2010-03-01

    Full Text Available This experimental work was aimed to study the moisture content, total lipids and fatty acid profile in the liver of wild and farmed freshwater major carp Catla catla of three different weight categories designated as W1 (601-900g, W2 (901- 1200g and W3 (1201-1500g. Seven fish specimens of each of the three weight categories of wild and farmed Catla catla were obtained from Trimu Head, Jhang and Fish Hatchery, Satiana Road and Faisalabad, respectively. The fish were dissected to remove the liver and after weighing, liver samples were prepared and subjected to chemical analysis. Wild Catla catla liver had a significantly (p Catla catla deposited significantly (p Catla catla. Saturated fatty acids C12:0, C14:0, C16:0, C18:0, C20:0 and C22:0 were identified with considerable percentages in the liver of Catla catla from both habitats and monounsaturated fatty acid C18:1 was found in considerable amounts in the liver of both major carp. Polyunsaturated fatty acids such as C18:3 (n-6 and C20: 2 (n-6 were detected in the liver of the wild fish of W2 and W3 and was similar in the W3 weight category of the farmed species.Este trabajo experimental tiene como objetivo estudiar el contenido de humedad, lípidos totales y perfil de ácidos grasos de hígado de carpa de agua dulce Catla catla de tres categorías con peso diferentes designadas como W1 (601- 900g, W2 (901-1200g and W3 (1201-1500g. Siete muestras de pescados por cada una de las tres categorías de peso para Catla catla salvajes y criados fueron obtenidos de Trimu Head, Jhang and Fish Hatchery, Satiana Road y Faisalabad, respectivamente. Los pescados fueron diseccionados para obtener el hígado y las muestras de hígado fueron preparadas y sujetas a análisis químico. Catla catla salvaje tuvo un contenido de humedad significativamente mayor (p Catla catla criadas se depositaron mayores contenidos de lípidos en el hígado. La proporción de ácidos grasos saturados vario irregularmente en los l

  6. Environmental and human health risk assessment of organic micro-pollutants occurring in a Spanish marine fish farm

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Ivan, E-mail: ivanmuno@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Martinez Bueno, Maria J., E-mail: mjbueno@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Agueera, Ana, E-mail: aaguera@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Fernandez-Alba, Amadeo R., E-mail: amadeo@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain)

    2010-05-15

    In this work the risk posed to seawater organisms, predators and humans is assessed, as a consequence of exposure to 12 organic micro-pollutants, namely metronidazole, trimethoprim, erythromycin, simazine, flumequine, carbaryl, atrazine, diuron, terbutryn, irgarol, diphenyl sulphone (DPS) and 2-thiocyanomethylthiobenzothiazole (TCMTB). The risk assessment study is based on a 1-year monitoring study at a Spanish marine fish farm, involving passive sampling techniques. The results showed that the risk threshold for irgarol concerning seawater organisms is exceeded. On the other hand, the risk to predators and especially humans through consumption of fish is very low, due to the low bioconcentration potential of the substances assessed. - Exposure and effects of twelve organic micro-pollutants are evaluated at a Spanish fish farm.

  7. Bacterial diversity in the intestine of young farmed puffer fish Takifugu rubripes

    Science.gov (United States)

    Li, Yanyu; Zhang, Tao; Zhang, Congyao; Zhu, Ying; Ding, Jianfeng; Ma, Yuexin

    2015-07-01

    The aim of the study was to examine the bacterial community associated with the intestinal mucus of young farmed puffer fish Takifugu rubripes. Polymerase chain reaction and partial 16S rDNA sequencing was performed on DNA from bacteria cultivated on Zobell 2216E medium. All the isolates were classified into two phyla—Proteobacteria and Firmicutes. Proteobacteria were the dominant, culturable intestinal microbiota (68.3%). At the genus level, Vibrio, Enterobacter, Bacillus, Pseudomonas, Exiguobacterium, Staphylococcus, Acinetobacter, Pseudoalteromonas and Shewanella were isolated from the intestine, with representatives of the genera Vibrio, Enterobacter and Bacillus accounting for 70.7% of the total. This is the first report of Enterobacter, Bacillus, Exiguobacterium and Staphylococcus as part of the intestinal bacterial microflora in T. rubripes. The profile of the culturable bacterial community differed between samples collected from the same tank at 2-month intervals, as indicated by Bray-Curtis and Sorensen indices, and the impact on the intestinal physiology and health of puffer fish requires further investigation.

  8. The gross- and net-irrigation requirements of crops and model farms with different root zone capacities at ten locations in Denmark 1990-2015

    DEFF Research Database (Denmark)

    ten Damme, Loraine; Andersen, Mathias Neumann

    abstraction permits for irrigation. Here we present estimates of the gross and net irrigation water requirements for a range of agricultural crops and model farms in 10 locations across Denmark for the years 1990-2015. We generally found higher values for the irrigation requirement than previous studies...... conducted 40 years ago. The annual irrigation water requirement varied according to farm type (dairy, arable/pig and potatoes), location,soil type and especially year with more than 300%. Abstraction permits based on average values are deemed less suitable as they may restrict farmers’ production in one out...

  9. How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere.

    Science.gov (United States)

    Costello, Mark J

    2009-10-07

    Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry euro300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management.

  10. Net-energy analysis of integrated food and bioenergy systems exemplified by a model of a self-sufficinet system of dairy farms

    DEFF Research Database (Denmark)

    Markussen, Mads Ville; Pugesgaard, Siri; Oleskowicz-Popiel, Piotr

    2015-01-01

    rye grain and whey, and (4) a combination of (1) and (2). When assessing the energetic net-contribution to society from bioenergy systems, two types of problems arise: how to aggregate non-equivalent types of energy services and how to account for non-equivalent types of inputs and coproducts from...... the farming? To avoid the first type, the net output of liquid fuels, electricity, useful heat, and food were calculated separately. Furthermore, to avoid the second type, all scenarios were designed to provide self-sufficiency with fodder and fertilizer and to utilize coproducts within the system...

  11. PHYTOPLANKTON COMPOSITION AT THE FISH AND SHELLFISH FARM IN THE KALDONTA BAY (CRES ISLAND

    Directory of Open Access Journals (Sweden)

    Marija Tomec

    2004-12-01

    Full Text Available The Kaldonta Bay is situated at the south–western coast of the Cres island in the Lošinj channel, rather protected from larger influence of general sea water current. In the Bay there are installed 44 floating cages of 5 by 10 m dimensions. The cages are used for the culture of about 70 tons of sea water fish: gilthead sea bream (Sparus aurata, sea bass (Dicentrarchus labrax, sharp–snouted sparus (Diplodus puntazzo and dentex (Dentex dentex. Besides some physico–chemical parameters (sea water temperature, transparence and salinity, special attention has been paid to the qualitative composition of net phytoplankton. Investigations were performed in the period of May, September and December 2003 and February 2004 at five locations in the Kaldonta Bay (Figure 1 at the depths of 0.5 m, 5 m, 10 m and 1 m from the bottom. According to the physico–chemical parameters, sea water temperature was influenced by the temperature of the environment, and the transparence suggested to the oligotrophic situation in the investigated aquatorium. Qualitative composition of net phytoplankton comprised 161 microphytic species belonging to the systematic compartments of Cyanobacteria, Chrysophyta and Dinophyta (Table 1. The most numerous algal group were diatoms or Bacillarophyceae (98 species or 61%, with relative frequencies of species from 1 to 7. Taxonomic composition of diatoms showed Chaetoceros–Rhizosolenia (Proboscia to be the dominant community. Diatom species was the most abundant in late autumn period (beginning of December. The second most important comparatment were Dinophyta (55 species or 34.1%, with the dominant genera Ceratium and Protoperidinium. During the investigation, the representatives of Dinophyta did not show large variety of species in the water column. Relative frequency of the species was 1, rarely 2 and 3. Dinophyts were the most abundant in September. From Cyanobacteria (5 species or 3.1% only filamentous algae were determined

  12. Push net fishing seems to be responsible for injuries and post fishing mortality in glass eel in the Vilaine estuary (France in 2007

    Directory of Open Access Journals (Sweden)

    Briand C.

    2012-01-01

    Full Text Available Post fishing mortality of the glass eel was monitored in 2007 in the Vilaine estuary. The mortality of the glass eels varied from 2 to 82% (mean 42% in the two days following the fishing. The mortality of samples collected by hand nets or from the trapping ladder was null. Alterations of the skin mucus were analyzed by the use of Indigo carmine. The mortality was significantly correlated with body injuries, but not to other environmental factors. The presence of a large injury on the body systematically led to the death of the glass eels, and among these dead glass eels, only 3.5% had no external injury. These results are discussed, along with the results from other estuaries, with a view to transport glass eels across Europe, with the objective of restoring the eel stock.

  13. Remote influence of off-shore fish farm waste on Mediterranean seagrass (Posidonia oceanica) meadows.

    Science.gov (United States)

    Ruiz, J M; Marco-Méndez, C; Sánchez-Lizaso, J L

    2010-04-01

    The aim of this study was estimating the remote influence of waste dispersed from a large off-shore fish farm complex (6197 ton year(-1)) on the near-shore Posidonia oceanica meadow (26-27 m deep) located at a distance of 3 km. Measurements of isotopic nitrogen content in epiphytes and seagrass leaf tissues, epiphyte biomass, shoot size, herbivory pressure, shoot density and seagrass meadow cover, performed in this meadow (FA area) were compared with those obtained in an undisturbed control meadow (CA area) to evaluate: (1) the remote influence of waste and (2) the impact of such influence on seagrass condition. In addition, delta(15)N measurements in particulate organic matter of natural and anthropogenic origin were used in a single-isotope mixing model to elucidate the relative contributions of these sources to the isotopic N signal measured in epiphytes and leaf tissues. Total tissue N content was similar between meadow areas, but delta(15)N signatures were significantly higher in the FA area than in the CA area both in epiphytes and seagrass leaf tissues. Results from the mixing model, together with available information on local currents and previous studies, support the conclusion that the dispersion of farm wastes over large areas (spanning kilometres) are responsible for the elevated delta(15)N signatures found in the FA meadow area. Despite this, no changes in meadow structure were detected and only some changes at the level of seagrass community (epiphytes abundances and herbivores activity) could be interpreted at the light of nutrient-induced effects in the FA area. Results from this study indicate that concentrating aquaculture facilities in off-shore areas is a strategy not totally exempt of environmental risk on near-shore sensitive habitats such as seagrass meadows. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Gill net selectivity and catch rates of pelagic fish in tropical coastal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-05

    Nov 5, 2008 ... fish communities includes a decrease in their abundance, changes in age structure, size composition and species composition. ... used methods for sampling fish populations in reservoirs and lakes (Boy and Crivelli, ... The size frequency distribution of the population and the selectivity parameters are thus ...

  15. The influence of fish culture in floating net cages on microbial indicators of water quality

    National Research Council Canada - National Science Library

    Gorlach-Lira, K; Pacheco, C; Carvalho, L C T; Melo Júnior, H N; Crispim, M C

    2013-01-01

    ... (Oreochromis niloticus) in floating net cages. The physico-chemical parameters, counts of mesophilic total aerobic bacteria, total and thermotolerant coliforms and fecal streptococci, and the presence of Escherichia coli in samples of water...

  16. New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India

    Directory of Open Access Journals (Sweden)

    Dev Kumar Verma

    2015-12-01

    Full Text Available Abstract Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38 of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18% were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6 grouped with F. suncheonense, two strains (Fl6I2, Fl6I3 with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1 clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.

  17. Fish schooling as a basis for vertical axis wind turbine farm design.

    Science.gov (United States)

    Whittlesey, Robert W; Liska, Sebastian; Dabiri, John O

    2010-09-01

    Most wind farms consist of horizontal axis wind turbines (HAWTs) due to the high power coefficient (mechanical power output divided by the power of the free-stream air through the turbine cross-sectional area) of an isolated turbine. However when in close proximity to neighboring turbines, HAWTs suffer from a reduced power coefficient. In contrast, previous research on vertical axis wind turbines (VAWTs) suggests that closely spaced VAWTs may experience only small decreases (or even increases) in an individual turbine's power coefficient when placed in close proximity to neighbors, thus yielding much higher power outputs for a given area of land. A potential flow model of inter-VAWT interactions is developed to investigate the effect of changes in VAWT spatial arrangement on the array performance coefficient, which compares the expected average power coefficient of turbines in an array to a spatially isolated turbine. A geometric arrangement based on the configuration of shed vortices in the wake of schooling fish is shown to significantly increase the array performance coefficient based upon an array of 16 x 16 wind turbines. The results suggest increases in power output of over one order of magnitude for a given area of land as compared to HAWTs.

  18. Occurrence of Antimicrobial Resistance in Fish-Pathogenic and Environmental Bacteria Associated with Four Danish Rainbow Trout Farms

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2000-01-01

    Surveillance of bacterial susceptibility to five antimicrobial agents was performed during a 1-year period in and around four freshwater fish farms situated along a stream in western Denmark Besides assessing the levels of antibiotic resistance among the culturable fraction of microorganisms...... and outlet samples, the increase of the antibiotic-resistant proportions observed among the culturable microflora was more pronounced and statistically significant among the motile aeromonads. High levels of individual and multiple antimicrobial resistances were demonstrated within the collected...

  19. Shading and alterations of the sediment: in situ experiments to mimic impacts of fish farms on a Mediterranean coastal ecosystem

    OpenAIRE

    Pete, Dorothée; Velimirov, Branko; Lepoint, Gilles; Gobert, Sylvie

    2010-01-01

    In the Mediterranean coastal zone, the seagrass Posidonia oceanica forms underwater meadows which sustain a high biodiversity and has many important roles (production of oxygen, protection of coasts, ...). Unfortunately, they are more and more threaten, notably by the increasing development of aquaculture. Indeed, fish farms increase the biomass of phytoplankton organisms in the water column (leading to a shading effect) and modify the sediment, which entail the disappearance of the seagrass....

  20. Occurrence of antibiotic resistance and characterization of resistant genes and integrons in Enterobacteriaceae isolated from integrated fish farms south China

    Science.gov (United States)

    Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.

    2011-01-01

    Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

  1. The bottlenose dolphin Tursiops truncatus foraging around a fish farm: Effects of prey abundance on dolphins’ behavior

    Directory of Open Access Journals (Sweden)

    Bruno Díaz LÓPEZ

    2009-08-01

    Full Text Available The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied. The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond, individually and as groups, to the relative abundance of prey around a fish farm. Detailed views of dolphins’ behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data. A total of 2150 dive intervals were analyzed, corresponding to 342 focal samples, lasting over 34 hours. Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds. This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area. This study’s results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding, dolphins did not modify dive duration. Additionally, underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities. Thus, bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey. When top predators display behavioral responses to activities not directed at them, the task of studying all possible effects of human activities can become even more challenging [Current Zoology 55(4: 243–248, 2009].

  2. Effect of Fish Meal Level on Growth, Food Digestibility and Fur Properties of Farmed Mink (Mustela vison

    Directory of Open Access Journals (Sweden)

    HT Korhonen

    2012-01-01

    Full Text Available Abstract. Our study sought to determine the effects of normal vs high fish meal levels in the diet on the growing-furring process and apparent food digestibility of farmed male mink (Mustela vison. The subjects were two groups of juvenile dark mink born in May and weaned in August. The experiment started after weaning with two diet groups: (1 normal level of fish meal (NOR, i.e. 4.5% of diet, and (2 high level of fish meal (HIGH, i.e. 10.0% of diet. We found that the mink on the high fishmeal (HIGH diet consumed slightly more fresh food than the mink on the normal fishmeal diet (NOR (total consumption 30.6 kg vs 28.1 kg. The mink in the NOR group ingested almost the same amount of food as dry matter and energy as the mink in the HIGH group. On October 22, the body weights of the HIGH group animals were significantly higher than those of the NOR animals. At the final weighing on December 3 (at pelting, a tendency for the body weights of NOR mink was noted to be lower than those of HIGH mink. Skin length was significantly shorter in NOR than in HIGH mink. The number of white wool skins (i.e. fur defect was higher in NOR than in HIGH mink (4 vs 2 skins. Statistically significant differences in other fur variables were not found between the groups. The apparent digestibility of protein, fat and organic matter was significantly better in HIGH than in NOR mink. Our findings tempt us to conclude that the proportion of fish products, at least those of fishmeal, can be increased in the diet of farm-raised juvenile mink. Keywords: farm-raised mink, feeding, fish products, diet, growing-furring period Animal Production 14(1:63-69, January 2012

  3. Technical report on the environmental monitoring of the cage area at the Source of the Nile (SON) Fish Farm for quarter 1: January-March 2015

    OpenAIRE

    Ndawula, L.M.; Ocaya, H.; Pabire Ghandi, W.; Musubika, S.; Naluwairo, J.; Magezi, J.; Kiggundu, V.; Namulemo, G.; Nsega, M.

    2015-01-01

    Source of the Nile (SON) fish farm is located at Bugungu in Napoleon Gulf, northern Lake Victoria. The proprietors of the farm have a collaborative arrangement with NaFIRRI, a lead agency in fisheries research and innovations, to undertake quarterly environment monitoring surveys at the farm. The agreed areas for monitoring are: selected physico-chemical parameters (i.e. temperature, dissolved oxygen, pH, conductivity, secchi depth); total suspended solids (TSS); nutrient status; BOD5) and bi...

  4. Effects of gill-net fishing on marine birds in a biological hotspot in the northwest Atlantic.

    Science.gov (United States)

    Davoren, Gail K

    2007-08-01

    Marine biological hotspots, or areas where high abundances of species overlap in space and time, are ecologically important areas because energy flow through marine food webs, a key ecosystem process, is maximized in these areas. I investigated whether top predators aggregated at persistent spawning sites of a key forage fish species, capelin (Mallotus villosus), on the NE coast of Newfoundland during July and August 2000-2003. By examining the distributional patterns of top predators through ship-based surveys at multiple spatial and temporal scales, I found that the biomasses of birds-dominated by Common Murres (Uria aalge)-and mammals-dominated by whale species-were concentrated along the coast, with a biological hotspot forming near two persistent spawning sites of capelin in all years. The formation of this hotspot was well defined in space and time from middle of July to middle of August, likely coinciding with the spawning chronology of capelin. Within this hotspot, there was a high spatial and temporal overlap of Common Murres and gill nets set to capture Atlantic cod (Gadus morhua). This resulted in breeding murres becoming entangled in gill nets while feeding on spawning capelin. Despite an acknowledged uncertainty of bycatch mortality, estimates for the larger regional-scale area (1936-4973 murres/year; 0.2-0.6% of the breeding population) underestimated mortality relative to estimates within the hotspot (3053-14054 murres/year; 0.4-1.7%). Although fishing effort for Atlantic cod has declined substantially since the groundfish moratorium in 1992, chronic, unnatural, and additive mortality through bycatch continues in coastal Newfoundland. Restricted use of gill nets within this and other biological hotspots during the capelin spawning period appears to be a straightforward application of the "ecological and biologically significant area" management framework in Canada's Oceans Act. This protection would minimize murre bycatch and maintain ecosystem

  5. Can the Global Adoption of Genetically Improved Farmed Fish Increase Beyond 10%, and How?

    Directory of Open Access Journals (Sweden)

    Ingrid Olesen

    2015-05-01

    Full Text Available The annual production from global aquaculture has increased rapidly from 2.6 million tons or 3.9% of the total supply of fish, shellfish and mollusks in 1970, to 66.7 million tons or 42.2% in 2012, while capture fisheries have more or less leveled out at about 90 million tons per year since the turn of the century. Consequently, the future seafood supply is likely to depend on a further increase of aquaculture production. Unlike terrestrial animal farming, less than 10% of the aquaculture production comes from domesticated and selectively bred farm stocks. This situation has substantial consequences in terms of poorer resource efficiency, poorer product quality and poorer animal welfare. The history of biological and technical challenges when establishing selective breeding programs for aquaculture is discussed, and it is concluded that most aquaculture species may now be domesticated and improved by selection. However, the adoption of selective breeding in aquaculture is progressing slowly. This paper reports on a study carried out in 2012 to identify key issues to address in promoting the development of genetically improved aquaculture stocks. The study involved semi structured interviews of 34 respondents from different sectors of the aquaculture society in East and Southeast Asia, where 76% of the global aquaculture production is located. Based on the interviews and literature review, three key factors are identified: (i long-term public commitment is often needed for financial support of the breeding nucleus operation (at least during the first five to ten generations of selection; (ii training at all levels (from government officers and university staff to breeding nucleus and hatchery operators, as well as farmers; and (iii development of appropriate business models for benefit sharing between the breeding, multiplier and grow-out operators (whether being public, cooperative or private operations. The public support should be invested in

  6. Fish farm and water quality management - doi: 10.4025/actascibiolsci.v35i1.10086

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Sipaúba Tavares

    2012-12-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Fish farms’ water quality management is analyzed with regard to the management employed and the different trophic states are compared within the system during the dry and rainy seasons. Six sites were marked two in the water supply (P1 and P2, and four within the fish farm (P3 to P6 . Whereas sites P1 and P2 (water supply were characterized as oligotrophic, the others were mesotrophic and eutrotrophic sites. Environmental variables, mainly nutrients, conductivity, COD, BOD5 and TSS tended to increase as from P3 due to management and fertilization. Greater impact has been registered in the fish farm under analysis for variables COD, ammonia, total phosphorus and TSS during the discharge and pond emptying period. Frequent monitoring of water quality should be undertaken in fish breeding and plankton production ponds, especially in those close to P3 and P4. Removal of sediment in decantation lake or P5 is also recommended to decrease nutrient concentrations, especially phosphorus, accumulated on the bottom soil.

  7. IMPACTS OF FISH FARM DAMS ON TEMPORAL AND SPATIAL DISTRIBUTION OF Astyanax cf. bimaculatus IN MICROBASINS OF THE MACHADO RIVER (RONDÔNIA, BRAZIL

    Directory of Open Access Journals (Sweden)

    Marcos de Almeida Mereles

    2017-06-01

    Full Text Available The present study evaluated the effects of fish farm dams on spatial and temporal distribution of lambari Astyanax cf. bimaculatus in five headwater streams of the Machado River basin, Rondônia State, Brazil. The results show that fish farm dams are spatially separating wild lambari populations into upstream and downstream groups. Moreover, it was observed that the dry and rainy seasons influence the abundance and presence of A. cf. bimaculatus in these areas, while limnological parameters did not differ y in the streams. Additionally, it was shown that fish farm dams built in the headwater stream areas impede the migratory routes of A. bimaculatus, and also possibly the local movements of resident fish populations. Therefore, before the implementation of new farm dams using natural streams in the future, mitigation plans should include adequate access routes for fish to travel between upstream and downstream areas, in order to avoid adversely affecting their wild populations. Keywords: Fish farm dams; lambari fish; Madeira River; microbasins; population parameters.

  8. Correction of algocenosis by the preparation of komplezim in experimental ponds of fish-farm Nyvka

    Directory of Open Access Journals (Sweden)

    L. Dragan

    2016-01-01

    Full Text Available Purpose. To investigate the effect of the bacterial preparation "Komplezim", which is recommended for the prevention of mass reproduction of blue-green algae through algocoenosis correction, water cleaning and sanitary regime restoration, for the biological balance and self-purification of natural and farmed fish ponds of all sizes exposed to artificial or natural pollution. Methodology. The studies were carried out during 30 days in a 0.01 hectare pond with a depth of 1.0–1.5 m. The doses of the bacterial preparation "Komplezim" in the form of a solution were applied over the water surface of the experimental pond. The conventional techniques of hydrochemistry and hydrobiology were used to perform hydroecological studies. Findings. The study results showed that after the exposure of the bacterial preparation "Komplezim", pH level of water and oxidation rates were within the acceptable limits. Permanganate and dichromate oxidation decreased in the same manner in the middle and end of the experiment compared to initial values. Calcium, magnesium, and sulfate levels were lower compared to control values. This effect can be explained by the fact that bacteria from the “Komplezim” composition in aquatic medium started intensive metabolizing the products of organic decomposition enriched in calcium, magnesium and sulfates. The consequence of the application of "Komplezim" was an increase in the concentration of organic chlorides simultaneously with nitrites. The obtained results indicate that bacteria strains included in the “Komplezim” composition inhibit the processes of cyanobacteria reproduction by algocenosis correction and contributes to the optimization of hydrochemical conditions for pond fish rearing. Originality. The effect of the bacterial preparation "Komplezim" on the reproduction of blue-green algae and hydro-chemical composition of the water has been investigated for the first time. Practical value. Application of the

  9. U.S. Fish and Wildlife Service Moves toward Net-Zero Buildings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-03

    First they had a vision: welcome people into a building embracing environmental stewardship on land that is steeped in history. The designers of the U.S. Fish and Wildlife Service took this vision and designed a new energy-efficient and environmentally friendly visitor center for the Assabet River National Wildlife Refuge located in Sudbury, Massachusetts.

  10. NOVEL TSUNAMI BARRIERS AND THEIR APPLICATIONS FOR HYDROELECTRIC ENERGY STORAGE, FISH FARMING, AND FOR LAND RECLAMATION

    Directory of Open Access Journals (Sweden)

    Hans J. Scheel

    2014-10-01

    Full Text Available The tsunami hazard can be mitigated if the destructive waves generated from earthquakes and landslides can be reflected by a stable submerged vertical barrier before striking coastal communities or important structures. Building such deep walls by conventional submarine technology is difficult. The present study describes the principle and the erection of such submarine defensive walls by a relatively simple efficient and economic technology. This technology is based on lowering high- strength steel fences with horizontal anchors, or two parallel steel fences with distance holders, into the sea and fixing them with rocks deposited from top. Dredged material like gravel or sand can be used for additional filling. This Tsunami-Flooding Barrier (TFB extends a few meters above sea level and carries on top a concrete supply and service road protected on both sides against storm waves by concrete walls. Replaceable surge stoppers (parapets, wave return walls prevent overtopping and erosion of the seaward barrier face. The TFBs protect the coastline against tsunami and the highest storm waves from hurricanes, but also can provide protection from oil spills or other contaminations from the ocean and thus protect flora, fauna, coral reefs and beaches. Channels and gates allow navigation and can be closed quickly upon a tsunami or storm warning. The construction costs can be eventually compensated by using the reservoirs between coast and barriers for hydroelectric energy storage (using pump-turbines in the barriers or for fish-farming, or alternatively the reservoir can be filled with rocks, rubble, gravel, sand and covered with soil in order to reclaim new land. Tidal energy can be generated by installing turbines within these barriers. Also, this submarine architecture may be applied to protect pillars of bridges and offshore platforms, and for erecting “roads” into the sea to connect near-shore platforms and wind-parks with the coast and

  11. Influence of tubificid worms on nutrient fluxes across water-sediment interface in fish farm settling ponds

    Directory of Open Access Journals (Sweden)

    Puigagut J.

    2014-04-01

    Full Text Available The influence of tubificid worms on nutrient translocation from water to fish farm sediments accumulating in settling ponds was addressed under laboratory conditions. Small microcosms of 0.5 L were filled up with 35 g of sludge from a fish farm settling pond and 0.15 L of filtered settling pond water. The experimental set up consisted of one control line (no worms added, a second experimental line with 1 mg of tubificid worms·g-1 fresh sediment (550 individuals·m-2 and a third experimental line with 40 mg of tubificid worms·g-1 fresh sediment (22 000 individuals·m-2. Nutrients translocation was determined by monitoring overlaying water concentration of ammonia, nitrate and phosphate for ten days. Results showed that abundances of 550 individuals·m-2 had no significant influence on the fluxes of nutrients here considered. However, the influence of higher abundances of tubificids (22 000 individuals·m-2 was of significant extent on the translocation of nitrate and phosphate. Accordingly, bioturbation of tubificids caused 55% lower nitrate uptake by the sediment when compared to control conditions. Phosphorus released by the sediments of the control condition was ca. 90% higher than that recorded under abundances of tubificids (22 000 individuals·m-2. Results obtained allowed us to estimate that fish farm settling ponds highly colonized by tubificid worms (22 000 individuals·m-2 may contribute to decrease phosphorus discharge (in terms of soluble phosphorus in ca. 5 g of P·ton-1 of fish produced.

  12. Net-energy analysis of integrated food and bioenergy systems exemplified by a model of a self-sufficient system of dairy farms

    Directory of Open Access Journals (Sweden)

    Mads Ville Markussen

    2015-11-01

    Full Text Available Agriculture is expected to contribute in substituting of fossil fuels in the future. This constitutes a paradox as agriculture depends heavily on fossil energy for providing fuel, fodder, nutrients and machinery. The aim of this paper is to investigate whether organic agriculture is capable of providing both food and surplus energy to the society as evaluated from a model study. We evaluated bioenergy technologies in a Danish dairy farming context in four different scenarios: 1 vegetable oil based on oilseed rape, 2 biogas based on cattle manure and grass-clover lays, 3 bioethanol from rye grain and whey, and 4 a combination of 1 and 2. When assessing the energetic net-contribution to society from bioenergy systems, two types of problems arise: How to aggregate non-equivalent types of energy services, and how to account for non-equivalent types of inputs and co-products from the farming? To avoid the first type, the net output of liquid fuels, electricity, useful heat and food were calculated separately. Further, to avoid the second type, all scenarios were designed to provide self-sufficiency with fodder and fertilizer and to utilize co-products within the system. This approach resulted in a transparent assessment of the net-contribution to society, which is easy to interpret. We conclude that if 20% of land is used for energy crops, farm-gate energy self-sufficiency can be achieved at the cost of 17% reduction in amount of food produced. These results demonstrate the strong limitations for (organic agriculture in providing both food and surplus energy.

  13. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization.

    Science.gov (United States)

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11-4.28 and 4.78-7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52-3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48-4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26-9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield.

  14. Effects of Insect-Proof Net Cultivation, Rice-Duck Farming, and Organic Matter Return on Rice Dry Matter Accumulation and Nitrogen Utilization

    Science.gov (United States)

    Liu, Xin; Xu, Guochun; Wang, Qiangsheng; Hang, Yuhao

    2017-01-01

    Insect-proof net cultivation (IPN), rice-duck farming (RD), and organic matter return (OM) are important methods to realize sustainable development of rice production. A split-plot field experiment was performed to study the effects of IPN, RD, and OM on the rice yield, dry matter accumulation and N utilization. Results showed that compared to inorganic N fertilizer (IN), wheat straw return, and biogas residue return increased the rice yield by 2.11–4.28 and 4.78–7.67%, respectively, and also improved dry matter and N accumulation after the elongation stage (EG), dry matter and N translocation, and N recovery efficiency (NRE). These results attributed to an increase in leaf SPAD values and net photosynthetic rate (Pn) after the EG. Compared to conventional rice farming (CR), RD promoted the rice yield by 1.52–3.74%, and contributed to higher the leaf photosynthesis, dry matter and N accumulation, dry matter and N translocation, and NRE. IPN decreased the intensity of sun radiation in the nets due to the coverage of the insect-proof nets, which declined the leaf Pn, dry matter accumulation and translocation, N absorption and translocation, and NRE compared to open field cultivation (OFC). The rice yield of IPN were 2.48–4.98% lower than that of OFC. Compared to the interaction between CR and IN, the interaction between RD and OM improved the rice yield by 5.26–9.33%, and increased dry matter and N accumulation after the EG, dry matter and N translocation, and NRE. These results indicated that OM, RD and the interaction between RD and OM could promote dry matter accumulation and N utilization, which was beneficial to improve the rice yield. PMID:28174589

  15. Stable isotope evidence for the environmental impact of a land-based fish farm in the western Mediterranean

    Energy Technology Data Exchange (ETDEWEB)

    Vizzini, Salvatrice; Mazzola, Antonio

    2004-07-01

    Isotopic examination ({delta}{sup 13}C and {delta}{sup 15}N) of organic matter sources and consumers was used to assess the impact and trace the dispersal of wastewater from a land-based fish farm in western Mediterranean. The results provide evidence of the non-negligible effect of aquaculture facilities on the natural stable isotopic composition of organisms. Aquaculture waste entered the food web, altering the natural isotopic composition of organic matter sources at the base and the upper trophic levels. Nitrogen-rich fish waste mainly affected {delta}{sup 15}N values, while {delta}{sup 13}C showed less alteration. Waste seemed to disperse widely enough to affect the isotopic composition at the study site about 500 m from the outfall, while sites at 1 and 2 km from the outfall showed values that were similar to each other and different from those of the impacted site. The impact was detected at different ecosystem levels, although primary producers were more affected by fish farm waste taking up aquaculture-derived nutrients.

  16. The market performance and determinants of net returns to artisanal ...

    African Journals Online (AJOL)

    The result of the multiple regression analysis showed that age, household size, farming experience and access to credit were significant determinants of fishermen net returns while age, educational level, price of the product (fish) and transport cost were significant determinants of the marketers'(wholesalers and retailers) ...

  17. Susceptibility of juvenile sole Solea senegalensis to marine isolates of viral haemorrhagic septicaemia virus from wild and farmed fish.

    Science.gov (United States)

    López-Vázquez, C; Conde, M; Dopazo, C P; Barja, J L; Bandín, I

    2011-01-21

    The susceptibility of sole Solea senegalensis to infection with 3 viral haemorrhagic septicaemia virus (VHSV) strains obtained from wild Greenland halibut Reinhardtius hippoglossoides and farmed turbot Psetta maxima was demonstrated. Fish were infected by an intraperitoneal (i.p.), immersion or cohabitational route, and maintained at 16 degrees C. Infection trials showed that VHSV isolates were pathogenic for sole fingerlings by i.p. injection and waterborne exposure causing moderate levels of mortality (10 to 55%). In addition, the mortality observed in fish cohabitating with i.p.-infected sole confirms horizontal transmission of the virus. However, the low rates of mortality registered in this challenge suggest that there is a low dissemination of virus by the i.p.-infected sole, which results in lower secondary challenge of the cohabitating fish. External signs of disease included haemorrhaging of the ventral area and ascitic fluid in the body cavity. Dead fish were tested for VHSV by both cell culture and RT-PCR assay, using pools of kidney and spleen from 10 individuals. Virus was recovered from most of the pools composed of dead fish. The results obtained in this study not only demonstrate the susceptibility of sole to the VHSV strains employed but also indicate that wild VHSV marine isolates represent a potential risk for sole aquaculture.

  18. Application of micro bubble generator as low cost and high efficient aerator for sustainable fresh water fish farming

    Science.gov (United States)

    Budhijanto, Wiratni; Darlianto, Deen; Pradana, Yano Surya; Hartono, Muhamad

    2017-05-01

    This study aimed to apply a novel type of aerator called Micro Bubble Generator (MBG) for fresh water fish farming. The MBG was run based on the principle of venturi tube in which water was circulated through a narrowed channel so that air was sucked into the device and pushed by the flowing water to create micro-sized bubble. The MBG aerator was tested on the aquaculture of tilapia fish to be compared to conventional aerator (the bubbler currently used in aquaculture experiments) and control (container with no aeration). The population of 150 tilapia fish of the average initial length of 6.44 cm was tested in each container. The water quality parameters (COD, pH, and TAN) and fish growth parameters (length and weight) were observed for 68 days. The results highlighted the promising potential of MBG as affordable aerator to be applied in intensive aquaculture. Although the dissolved oxygen level did not differ significantly with the conventional aerator, MBG aerator indicated faster degradation of organic content in the water and induced faster growth of the fish as measured by their length and weight.

  19. CONDITIONS OF FISH FARMING IN NATURA 2000 AREAS, BASED ON THE EXAMPLE OF THE CATCHMENT OF BARYCZ

    Directory of Open Access Journals (Sweden)

    Katarzyna Tokarczyk-Dorociak

    2016-07-01

    Full Text Available One of the factors that contributed to the construction of approx.77 km2 offish ponds in the catchment of Barycz starting from the 13th century, which in turn transformed the woods into a mosaic of waters, forests and arable land, were the advantageous physiographic conditions. Fish farming operations conducted in this area led to the creation of a cultural landscape characterised by unique natural values, similar to the natural landscape.Approx.240 species of birds are observed here, of which 170 are nesting species. Due to its natural values, this area has been subject to natural reserve protection as part of the Landscape Park "Dolina Baryczy" (the Barycz Valley. It was entered in the "Living Lakes" list and it is protected under the Ramsar Convention as well as under the European nature protection network Natura 2000.The established forms of nature protection mean the introduction of a certain binding regime, pursuant to which the economic activity conducted in protected areas must take into account the prohibitions and orders introduced by documents that establish the said forms of protection. Additionally, there is a legal requirement to create a protection plan or conservation plan that constitutes a basis for the realisation of conservation-related objectives. A commercial company Stawy Milickie S.A. (public limited company operates in the area of this largest fish pond complex in Poland. The scope of its operations includes more than just the breeding and sale of freshwater fish (6500 ha of ponds but also environmental protection, environmental education and the development of tourism as well as stimulating the development and professional activation of local communities basing on the natural resources that exist in the catchment of Barycz. This study presents the conditions related to fish farming operations conducted in this area. Conducting an extensive management (i.e. often uneconomical from the economic point of view is a

  20. Looking through a dirty glass: how different can the characterization of a fish fauna be when distinct nets are used for sampling?

    Directory of Open Access Journals (Sweden)

    Gianfranco Ceni

    2013-10-01

    Full Text Available The present study compares fish species composition, dominance, and size-structure patterns at an open sand beach area (32°15'S, 52°46'W in Mirim Lake, RS, Brazil, estimated from samples collected with two distinct beach seine nets. The BS-9m net is 9 m long and 1.5 m high, and is made with a 5 mm multifilament mesh on its central portion and 12 mm on the side wings. The BS-30m net is 30 m long and 1.8 m high, with a 12 mm monofilament nylon mesh all over the net, except for a 30 cm strip made with a 12 mm multifilament mesh on the lower portion. Thirty hauls were performed with both nets resulting in a total of 849 fish captured, comprising 34 species. BS-9m was selective for individuals smaller than 60 mm TL and BS-30m for individuals larger than 60 mm TL. Low values of the faunal similarity (JI = 0.41, ANOSIM R = 0.2309, p < 0.0001 and numeric dominance (PSI = 0.46 indexes were revealed. We suggest that the concurrent use of both samplers provide a better description of the fish fauna of shallow areas. However, due to their robustness, rusticity, and ease of use and maintenance, small multifilament seines are indicated for regular work in environments without obstacles and with little open sand area available for sampling.

  1. Farmed Atlantic salmon Salmo salar L. parr may reduce early survival of wild fish.

    Science.gov (United States)

    Sundt-Hansen, L; Huisman, J; Skoglund, H; Hindar, K

    2015-06-01

    The study examined the density-mediated effects on growth, survival and dispersal of wild and farmed Atlantic salmon Salmo salar offspring in the period immediately following emergence, using a substitutive design. In small confined stream channels, wild parr coexisting with farmed parr had a significantly poorer survival, than wild parr alone. Density did not affect this relationship. In larger unconfined stream channels, wild parr coexisting with farmed parr entered a downstream trap in higher numbers than wild parr in allopatry. The results suggests that during the earliest life stages, farmed S. salar can outcompete wild S. salar, resulting in a reduced survival of wild S. salar. © 2015 The Fisheries Society of the British Isles.

  2. Pathogenicity and oxidative stress in Nile tilapia caused by Aphanomyces laevis and Phoma herbarum isolated from farmed fish.

    Science.gov (United States)

    Ali, Esam H; Hashem, Mohamed; Al-Salahy, M Bassam

    2011-03-16

    Identified (n = 17) and unidentified (n = 1) fish-pathogenic fungal species from 10 genera of Oomycetes and soil fungi were isolated from 40 infected freshwater fish samples of the species Oreochromis niloticus niloticus (Nile tilapia) and Clarias gariepinus (African catfish). Samples were collected from various fish farms in the Nile Delta, Egypt. Nile tilapia were tested in aquaria for their susceptibility to the commonest Oomycetes species, Aphanomyces laevis and Achlya klebsiana, and also against the 2 most prevalent pathogenic soil fungi, Paecilomyces lilacinus and Phoma herbarum. Two techniques were used: water bath exposure and intramuscular (subcutaneous) injection. Water bath exposure to the 2 species of Oomycetes caused greater mortalities of O. niloticus niloticus than intramuscular injection, but the reverse was true of the soil fungal species. Regardless of the infection method, the 2 Oomycetes species were more potent pathogens than the soil fungal species. In both gills and mytomal muscles of fish infected by A. laevis and P. herbarum, we measured and compared with controls the oxidative stress parameters total peroxide (TP), lipid peroxidation (LPO) and nitric oxide (NO), as well as levels of the antioxidants vitamin E and glutathione (GSH), and superoxide dismutase (SOD) and catalase (CAT) activities. Infection by these 2 fungal species through either spore suspension or spore injection significantly increased oxidative damage in gills and induced marked decrease in most studied antioxidants. In addition, both routes showed similar effects and A. laevis depressed the antioxidants CAT, vitamin E and GSH more than P. herbarum.

  3. Temporal and spatial dynamics of phytoplankton near farm fish in eutrophic reservoir in Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Ariadne do Nascimento Moura

    2012-06-01

    Full Text Available Spatial and temporal variations in phytoplankton communities in continental waters have received attention from limnologists, since they are differently influenced by many physico-chemical and biological factors. This study was undertaken with the aim to identify the environmental variables that influence the temporal and spatial dynamics of the phytoplankton near a fish farm in the Jucazinho reservoir, in a semi-arid region of Northeastern Brazil. Samples were taken from three sampling sites, at two depths during the rainy (Aug 2008, Feb and Mar 2009 and dry (Oct, Nov and Dec 2008 seasons. Phytoplankton was identified, density determined, and biomass values obtained. Concomitantly, abiotic analyses were performed for the characterization of the system. The reservoir was homogeneous with regard to the spatial-temporal variation in hydrological variables: water well oxygenated at the surface and anoxic at the bottom; pH ranging from neutral to alkaline; temperatures always above 25ºC; high turbidity; and high electrical conductivity at all sampling sites and both depths. For both seasons, there was limited nitrogen and high concentrations of phosphorus. Cyanophyta species were predominant, generally representing 80% of the phytoplankton biomass throughout practically the entire study, at all sampling sites and both depths. Co-dominance of cyanobacteria belonging to H1, MP, S1 and Sn associations was recorded in most of the months studied, except August 2008, when there was a substitution of the S1 association (Planktothrix agardhii by the P association (Aulacoseira granulata. Water temperature, precipitation and pH were the parameters with the greatest influence over the temporal variation in phytoplankton, whereas the vertical distribution of the phytoplankton biomass was directly related to the availability of light in the wáter column. There were no spatial or temporal differences in water quality, likely due to the fact that the sampling

  4. Fish farming in ponds and lakes to provide an important protein supplement to the food basket, and connected public health problems.

    Science.gov (United States)

    Shomrony, A

    1978-01-01

    Fish farming in ponds can be of great value in various ways: 1) By adding fat-free and relatively inexpensive animal protein to the food basket; 2) By removing waste water in a most hygienic as well as economic way; 3) By saving the cost of transport and storage of meat from warm-blooded animals by breeding fish near the consumer. Our task is to prevent the spread of disease in fish, to prevent transmission of health hazards to man, and to inspect the quality of fish all along the line from the ponds through marketing to the consumer.

  5. The effect of in situ shading on a Posidonia oceanica meadow situated within a fish farm induced moderately nutrient enriched environment.

    Science.gov (United States)

    Puhr, Kristian; Pikelj, Kristina

    2012-08-01

    The aim of this research was to explore the possibility of a successful and balanced integration of fish farming installations into an ecosystem dominated by Posidonia oceanica (L.) Delile species. We selected light, temperature, seabed topography, sediment characteristics, meadow density, bottom coverage, maximum leaf length and lower depth limit as principle components in assessing the influence of the fish farm. All P. oceanica descriptors showed significant correlation with light deprivation effect while sediment organic matter content revealed slightly higher values than normal, increasing with distance from the cages. The results point to a conclusion that in such lightly nutrient enriched ecosystems, the seagrass growth and distribution are principally controlled by the shadow that cages cast on the seabed below, and that when carefully planned, fish farms do not necessarily degrade the health status of the surrounding area, but in fact facilitate a transition into a secondary stable state. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The Sustainability of Aquaculture as a Farm Enterprise: Impacts and Consequences of Fish Culture in Rwanda.

    Science.gov (United States)

    Molnar, Joseph J.; And Others

    Rwanda, a small country in Africa, has experienced declines in per capita food production. Fish culture is one part of a many-stranded effort to increase food production and food security by intensifying the use of land resources to produce a much-needed protein crop. Beginning in 1983, the Rwanda National Fish Culture Project has assisted farmers…

  7. Stewardship and risk: An empirically grounded theory of organic fish farming in Scotland

    NARCIS (Netherlands)

    Georgakopoulos, G.; Ciancanelli, P.; Coulson, A.; Kaldis, P.E.

    2008-01-01

    It has long been assumed ownership gives farmers incentives to act as stewards of the land. On this basis, quasi-property rights are granted to fish farmers to encourage them to manage risks to the aquatic environment. This paper offers an empirically grounded theorisation of fish farmers’

  8. Updating the importance of lactic acid bacteria in fish farming: natural occurrence and probiotic treatments.

    Science.gov (United States)

    Gatesoupe, François-Joël

    2008-01-01

    Many recent papers have deepened the state of knowledge about lactic acid bacteria (LAB) in fish gut. In spite of high variability in fish microbiota, LAB are sometimes abundant in the intestine, notably in freshwater fish. Several strains of Streptococcus are pathogenic to fish. Streptococcus iniae and Lactococcus garvieae are major fish pathogens, against which commercial vaccines are available. Fortunately, most LAB are harmless, and some strains have been reported for beneficial effects on fish health. A major step forward in recent years was the converging evidence that LAB can stimulate the immune system in fish. An open question is whether viability can affect immunostimulation. The issue is crucial to commercialize live probiotics rather than inactivated preparations or extracts. There has been a regain of interest in allochthonous strains used as probiotics for terrestrial animals or humans, due to economical and regulatory constraints, but the short survival in sea water may limit application to marine fish. If viability is required, alternative treatments may include the incorporation of prebiotics in feed, and other dietary manipulations that could promote intestinal LAB. Antagonism to pathogens is the other main feature of candidate probiotics, and there are many reports concerning mainly carnobacteria and Enterococcus. Some bacteriocins were characterized which may be of interest not only for aquaculture, but also for food preservation.

  9. Effects of exotic fish farms on bird communities in lake and marine ecosystems.

    Science.gov (United States)

    Jiménez, Jaime E; Arriagada, Aldo M; Fontúrbel, Francisco E; Camus, Patricio A; Avila-Thieme, M Isidora

    2013-08-01

    Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

  10. Effects of exotic fish farms on bird communities in lake and marine ecosystems

    Science.gov (United States)

    Jiménez, Jaime E.; Arriagada, Aldo M.; Fontúrbel, Francisco E.; Camus, Patricio A.; Ávila-Thieme, M. Isidora

    2013-08-01

    Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

  11. The Relationship between the Harmful Algal Blooms (HABs Phenomenon with Nutrients at Shrimp Farms and Fish Cage Culture Sites in Pesawaran District Lampung Bay

    Directory of Open Access Journals (Sweden)

    Qadar Hasani

    2012-12-01

    Full Text Available The phenomenon of harmful algal blooms (HABs in the Lampung Bay has been reported by many researchers. The occurrence of HABs may be due to the increase of nutrient (N and P as results of waste water of aquaculture (shrimp farms, hatcheries and fish cage farms. This study aim to determine the relationship between N and P concentrations in some aquaculture sites with harmful algal blooms. The analysis revealed the differences concentration of N and P at each different shrimp farms and fish cage farms sites (Hurun, Sidodadi, Ringgung, and Cikunyinyi Bay. The result showed that the increase of N and P concentration were followed by the increase of harmful phytoplankton populations. High density HABs were found in this study, such as: Ceratium furca with the highest density at 5.314x106 cells l-1, Trichodesmium erithraeum 1.05x105 cells l-1 and Noctiluca scintilans 5.99x104 cells l-1. The Multiple regression and canonical corelation analysis (CCA also indicated a strong positive relationship between N and P with the HABs at the shrimp farms and fish cage farms sites in the Lampung Bay.

  12. Using hierarchical Bayesian multi-species mixture models to estimate tandem hoop-net based habitat associations and detection probabilities of fishes in reservoirs

    Science.gov (United States)

    Stewart, David R.; Long, James M.

    2015-01-01

    Species distribution models are useful tools to evaluate habitat relationships of fishes. We used hierarchical Bayesian multispecies mixture models to evaluate the relationships of both detection and abundance with habitat of reservoir fishes caught using tandem hoop nets. A total of 7,212 fish from 12 species were captured, and the majority of the catch was composed of Channel Catfish Ictalurus punctatus (46%), Bluegill Lepomis macrochirus(25%), and White Crappie Pomoxis annularis (14%). Detection estimates ranged from 8% to 69%, and modeling results suggested that fishes were primarily influenced by reservoir size and context, water clarity and temperature, and land-use types. Species were differentially abundant within and among habitat types, and some fishes were found to be more abundant in turbid, less impacted (e.g., by urbanization and agriculture) reservoirs with longer shoreline lengths; whereas, other species were found more often in clear, nutrient-rich impoundments that had generally shorter shoreline length and were surrounded by a higher percentage of agricultural land. Our results demonstrated that habitat and reservoir characteristics may differentially benefit species and assemblage structure. This study provides a useful framework for evaluating capture efficiency for not only hoop nets but other gear types used to sample fishes in reservoirs.

  13. Screening of ecotoxicological, qualitative and reproductive variables in male European sea bass Dicentrarchus labrax (L.) reared in three different fish farms: Facility location and typology.

    Science.gov (United States)

    Cangialosi, Maria Vittoria; Corsi, Ilaria; Bonacci, Stefano; Sensini, Cristiana; Cicero, Nicola; Focardi, Silvano; Mazzola, Antonio

    2013-04-01

    The aim of this study was to investigate the influence of both facility location and typology of fish farm on some ecotoxicological, qualitative and reproductive variables in European sea bass Dicentrarchus labrax L. Several variables were investigated: gonado-somatic index (GSI), liver-somatic index (LSI); 7-ethoxyresorufin-O-deethylase (EROD), benzo(a)pyrene monooxygenase and acetylcholinesterase activities; glutathione (GSH), testosterone, 17β-estradiol, total lipid, phospholipid (PL) and triglyceride contents. In addition, the histological sections of gonads were examined. Results suggest that LSI, EROD activity, GSI, GSH, PL, hormone levels and gonad morphology were influenced by different facility locations and typologies of fish farm.

  14. DETERMINATION OF PROTEIN FRACTIONS IN THE BLOOD OF THE HIGH ECONOMIC VALUE FISH FARMED SPECIES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    T. PATRICHE

    2008-10-01

    Full Text Available In aquaculture, as in any other sector where work is carried out on live bodies, to get a high production yield depends upon maintenance and monitoring of an unaltered health condition of the biological material. To monitor the health condition of the biological material in a fish farm allows us to establish the preventive measures required to stop the spread of disease and the treatment to be applied in case a mass disease occurs. For this reason to know the value of the total protein and the protein fractions in serum enables us to differentiate the normal physiological condition of the fish material under research, from the eventual pathological modifications having occurred due to the defence reaction of the body. The most part of diseases have but a little influence on the concentration of the total protein in the blood, but some influence on certain protein fractions, and they alter the ratio between albumins and globulins. The level of the total protein in serum is, first of all, a synthetic indicator of the nutritional condition of the body, presenting, at the same time, ample qualitative and quantitative variations depending on species, age, sex, stage of sexual maturity, water temperature and especially in correlation with the health condition of fish. Alterations of the ratio albumins/globulins or of the ratio between different protein fractions have important pathological implications, especially concerning the immunity capacity of fish, a decrease below 0.3 in value of the ratio albumins/globulins in serum being significant for the health condition of fish.

  15. Phytoplankton, fish pathology, and other data from net, bottle casts, and fish trawls in the Lower Cook Inlet and other locations from NOAA Ship DISCOVERER and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 1975-09-12 to 1976-06-01 (NODC Accession 7601874)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phytoplankton, fish pathology, and other data were collected from net, bottle casts, and fish trawls in the Lower Cook Inlet and other locations from NOAA Ship...

  16. Fish survey, fishing duration, and other data from net trawls in the Bering Sea from NOAA Ship MILLER FREEMAN and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 1975-08-07 to 1975-10-21 (NODC Accession 7601681)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Bering Sea from NOAA Ship MILLER FREEMAN and other platforms from 07 August 1975...

  17. Fish survey, fishing duration, and other data from net trawls in the Bering Sea from NOAA Ship MILLER FREEMAN and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 1976-04-01 to 1976-08-09 (NODC Accession 7700847)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Bering Sea from NOAA Ship MILLER FREEMAN and other platforms from 01 April 1976...

  18. Fish survey, fishing duration, and other data from net trawls from NOAA Ship MILLER FREEMAN and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 1975-05-03 to 1976-08-04 (NODC Accession 7800029)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls from NOAA Ship MILLER FREEMAN and other platforms from 03 May 1975 to 04 August 1976....

  19. Fish survey, fishing duration, and other data from net trawls in the Bering Sea and other locations from the G. B. REED and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 21 September 1948 to 19 February 1976 (NODC Accession 7601767)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Bering Sea and other locations from the G. B. REED and other platforms from 21...

  20. The importance of live-feed traps - farming marine fish species

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Nielsen, Max; Abate, Tenaw Gedefaw

    2017-01-01

    This article analyses the challenges of different live-feed regimes for the rearing of marine finfish larvae and discusses the potential alternative live feeds to avert a future live-feed trap. Live feeds are indispensable for the successful rearing of larvae of most marine fish species. Brine...... shrimps (Artemia) and rotifers comprise the live feeds of choice in marine aquaculture today. However, their nutritional composition is deficient in especially essential fatty acids, and enrichment with fish oil is needed. Fish oil is considered a limited resource owing to its origin in fully exploited...... wild fish stocks. Moreover, fluctuations of the natural population of Artemia will, most likely, influence future availability and prices. This emphasizes the need for optimal exploitation of available live-feed resources and development of new sustainable alternatives, such as copepods. An array...

  1. Base line studies North Sea wind farms: pelagic fish survey report 2

    NARCIS (Netherlands)

    Couperus, A.S.; Ybema, M.S.; Grift, R.E.

    2003-01-01

    The Dutch Government has decided to allow the construction of a Near Shore Wind Farm (NSW) demonstration project under the condition that a monitoring programme on - among other things - the ecological impacts is carried out. The Dutch government is responsible for providing a thorough description

  2. 76 FR 54072 - Emergency Assistance for Livestock, Honeybees, and Farm-Raised Fish Program, Livestock Indemnity...

    Science.gov (United States)

    2011-08-31

    ... to the Supplemental Agricultural Disaster Assistance Programs, authorized by the Food, Conservation... Agricultural Disaster Assistance Programs AGENCY: Farm Service Agency, USDA. ACTION: Final rule, technical... This rule makes a technical correction to 7 CFR 760, subpart C, ``Emergency Assistance for Livestock...

  3. Base line studies North Sea wind farms: Final report pelagic fish

    NARCIS (Netherlands)

    Grift, R.E.; Tulp, I.Y.M.; Ybema, M.S.; Couperus, A.S.

    2004-01-01

    The Dutch government has decided to allow the construction of a Near Shore Wind Farm (NSW) demonstration project under the condition that a monitoring programme on - among other things - the ecological impacts is carried out. The Dutch government is responsible for providing a thorough description

  4. Base line studies North Sea wind farms: strategy of approach for pelagic fish

    NARCIS (Netherlands)

    Grift, R.E.; Couperus, A.S.; Ybema, M.S.

    2003-01-01

    The Dutch Government has decided to allow the construction of a Near Shore Wind Farm (NSW) demonstration project under the condition that a monitoring programme on - among other things - the ecological impacts is carried out. The Dutch government is responsible for providing a thorough description

  5. Absence of viral hemorrhagic septicemia virus (VHSV) and infectious hemorrhagic necrosis virus (INHV) in a Tunisian fish farm: a case study.

    Science.gov (United States)

    Cherif, N; Hammami, S

    2012-01-01

    Beyond the obvious problems related to the sustainable management of wild stocks, current fish farming practices in the Mediterranean area entail important environmental risks and potential outbreaks of fish diseases linked to massive translocations across regional boundaries. Viral haemorrhagic septicaemia (VHS) and infectious hematopoietic necrosis (IHN) are well-known fish diseases caused by the VHSV and IHNV viruses, and positive cases are subject to obligatory reporting to the World Organisation for Animal Health (OIE). In August 2004, the OIE published the first record of a VHS outbreak in a sea bass (Dicentrarchus labrax) aquaculture facility on the coast of the Mediterranean Sea. However, D. labrax is not considered as a susceptible host species for viral hemorrhagic septicaemia according to OIE's International Aquatic Animal Health Code (2009) and VHSV was not previously reported in the Mediterranean. In this sense and given the high risk of disease translocation associated with farmed fish in marine aquaculture, the present study was aimed at investigating the presence of VHSV and IHNV in stocks of sea bass and sea bream (Sparus aurata) reared inside a Tunisian coastal fish farm. Cell culture, IFAT and RT-PCR were applied to screen for both VHSV and IHNV in 69 pooled samples of sea bass and 24 pooled samples of sea bream. All three techniques showed the absence of both viruses within fish at the selected site.

  6. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus).

    Science.gov (United States)

    Besson, M; Komen, H; Aubin, J; de Boer, I J M; Poelman, M; Quillet, E; Vancoillie, C; Vandeputte, M; van Arendonk, J A M

    2014-12-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+Δt) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+Δt, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+Δt, the

  7. ASSESSMENT OF THE DEVELOPMЕNT OF POND FORAGE BASE WHEN REARING CARP (CYPRINUS CARPIO CARPIO FISH SEEDS AT FISH FARM «MERKURIY»

    Directory of Open Access Journals (Sweden)

    B. Grishin

    2015-09-01

    comprehensive assessment of the natural forage base in nursery ponds when rearing carp fish seeds in the conditions of forest-steppe zone of Vinnitsa region at the fish farm “Merkuriy”. Practical value. The obtained data allow rearing high quality young-of-the-year Lubin few scale carp, Antoninsko-Zozulenets carp and their reciprocal crosses.

  8. Global Aquaculture Performance Index (GAPI: The First Global Environmental Assessment of Marine Fish Farming

    Directory of Open Access Journals (Sweden)

    Jenna M.S. Stoner

    2013-09-01

    Full Text Available “Sustainable” is among the most sought after of all seafood product adjectives. Ironically it is also one of the most poorly defined and understood. The Global Aquaculture Performance Index (GAPI is the first tool to assess environmental performance of global marine aquaculture production, permitting direct comparison of disparate species, production methods and jurisdictions. Clear patterns emerge from this analysis; significant variation of environmental performance is driven by the species being farmed, significant room for improvement exists across the entire sector, the worst performing players are also the fastest growing, particularly within Asia, and perhaps most importantly, this work highlights the potential trap awaiting policy makers who focus too narrowly on farm production efficiency alone as a solution to diminishing seafood availability.

  9. Environmental Adult Education for Mitigating the Impacts of Climate Change on Crop Production and Fish Farming in Rivers State of Nigeria

    Science.gov (United States)

    Eheazu, Caroline L.; Ezeala, Joy I.

    2017-01-01

    The threats of climate change to human society and natural ecosystems have become a devastating environmental problem for crop production and fish farming in Nigeria. This is partly because farmers and fisher folk are known to adopt age-old methods that do not counter current global warming and climate change effects. The purpose of this study was…

  10. Molecular genetic analysis of stomach contents reveals wild Atlantic cod feeding on piscine reovirus (PRV infected Atlantic salmon originating from a commercial fish farm.

    Directory of Open Access Journals (Sweden)

    Kevin Alan Glover

    Full Text Available In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish.

  11. Molecular genetic analysis of stomach contents reveals wild Atlantic cod feeding on piscine reovirus (PRV) infected Atlantic salmon originating from a commercial fish farm.

    Science.gov (United States)

    Glover, Kevin Alan; Sørvik, Anne Grete Eide; Karlsbakk, Egil; Zhang, Zhiwei; Skaala, Øystein

    2013-01-01

    In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish.

  12. Molecular Genetic Analysis of Stomach Contents Reveals Wild Atlantic Cod Feeding on Piscine Reovirus (PRV) Infected Atlantic Salmon Originating from a Commercial Fish Farm

    Science.gov (United States)

    Glover, Kevin Alan; Sørvik, Anne Grete Eide; Karlsbakk, Egil; Zhang, Zhiwei; Skaala, Øystein

    2013-01-01

    In March 2012, fishermen operating in a fjord in Northern Norway reported catching Atlantic cod, a native fish forming an economically important marine fishery in this region, with unusual prey in their stomachs. It was speculated that these could be Atlantic salmon, which is not typical prey for cod at this time of the year in the coastal zone. These observations were therefore reported to the Norwegian Directorate of Fisheries as a suspected interaction between a local fish farm and this commercial fishery. Statistical analyses of genetic data from 17 microsatellite markers genotyped on 36 partially-degraded prey, samples of salmon from a local fish farm, and samples from the nearest wild population permitted the following conclusions: 1. The prey were Atlantic salmon, 2. These salmon did not originate from the local wild population, and 3. The local farm was the most probable source of these prey. Additional tests demonstrated that 21 of the 36 prey were infected with piscine reovirus. While the potential link between piscine reovirus and the disease heart and skeletal muscle inflammation is still under scientific debate, this disease had caused mortality of large numbers of salmon in the farm in the month prior to the fishermen's observations. These analyses provide new insights into interactions between domesticated and wild fish. PMID:23620726

  13. Combination of Slag, Limestone and Sedimentary Apatite in Columns for Phosphorus Removal from Sludge Fish Farm Effluents

    Directory of Open Access Journals (Sweden)

    Florent Chazarenc

    2010-08-01

    Full Text Available Laboratory scale studies have repeatedly reported high P-retention in slag, a by-product of the steel manufacturing industry. Thus, it has emerged as a potential material to increase P-removal from constructed wetlands (CWs. However, several limitations were highlighted by field experiments, including the high pH of treated water and clogging. We hypothesized that the addition of sedimentary rocks to slag would preserve P-removal properties while reducing the pH of treated water. Four 2.5 L-columns were filled with 100% apatite (column A; a 50% weight each mixture of limestone with apatite (column B; 10% steel slag located at the inlet, plus 45% limestone mixed with 45% apatite (column C; and a mixture of steel slag (10%, limestone (45% apatite (45% (column D. A synthetic effluent (26 mg P/L and a reconstituted sludge fish farm effluent containing 97 mg/L total suspended solids (TSS, 220 mg/L chemical oxygen demand (COD and 23.5 mg P/L phosphorus (P were applied sequentially during 373 and 176 days, under saturated flow conditions and 12–24 hours hydraulic residence time (HRT, respectively. Treatment performance, P-removal, pH and calcium (Ca2+ were monitored. Results indicated that columns that contained 10% weight steel slag resulted in a higher P retention capacity than the columns without steel slag. The highest P removal was achieved in column C, containing a layer of slag in the inlet zone, 45% apatite and 45% limestone. Feeding the columns with a reconstituted fish farm effluent led to biofilm development, but this had little effect on the P-removal. A combination of slag and sedimentary rocks represents a promising filtration material that could be useful downstream of CWs to further increase P-removal.

  14. Contribution of fish farming ponds to the production of immature Anopheles spp. in a malaria-endemic Amazonian town.

    Science.gov (United States)

    dos Reis, Izabel Cristina; Codeço, Cláudia Torres; Degener, Carolin Marlen; Keppeler, Erlei Cassiano; Muniz, Mauro Menezes; de Oliveira, Francisco Geovane Silva; Cortês, José Joaquin Carvajal; de Freitas Monteiro, Antônio; de Souza, Carlos Antônio Albano; Rodrigues, Fernanda Christina Morone; Maia, Genilson Rodrigues; Honório, Nildimar Alves

    2015-11-14

    In the past decade fish farming has become an important economic activity in the Occidental Brazilian Amazon, where the number of new fish farms is rapidly increasing. One of the primary concerns with this phenomenon is the contribution of fishponds to the maintenance and increase of the anopheline mosquito population, and the subsequent increase in human malaria burden. This study reports the results of a 2-year anopheline abundance survey in fishponds and natural water bodies in a malaria-endemic area in northwest Brazil. The objective of this study was to investigate the contribution of natural water bodies (rivers, streams, creeks, ponds, and puddles) and artificial fishponds as breeding sites for Anopheles spp. in Mâncio Lima, Acre and to investigate the effect of limnological and environmental variables on Anopheles spp. larval abundance. Natural water bodies and fishponds were sampled at eight different times over 2 years (early, mid and late rainy season, dry season) in the Amazonian town of Mâncio Lima, Acre. Anopheline larvae were collected with an entomological dipper, and physical, chemical and ecological characteristics of each water body were measured. Management practices of fishpond owners were ascertained with a systematic questionnaire. Fishponds were four times more infested with anopheline larvae than natural water bodies. Electrical conductivity and the distance to the nearest house were both significant inverse predictors of larval abundance in natural water bodies. The density of larvae in fishponds raised with increasing border vegetation. Fishponds owned by different farmers varied in the extent of anopheline larval infestation but ponds owned by the same individual had similar infestation patterns over time. Commercial fishponds were 1.7-times more infested with anopheline larvae compared to fishponds for family use. These results suggest that fishponds are important breeding sites for anopheline larvae, and that adequate management

  15. Integrated assessment of runoff from livestock farming operations: analytical chemistry, in vitro bioassays, and in vivo fish exposures

    Science.gov (United States)

    Cavallin, Jenna E.; Durhan, Elizabeth J.; Evans, Nicola; Jensen, Kathleen M.; Kahl, Michael D.; Kolpin, Dana W.; Kolodziej, Edward P.; Foreman, William T.; LaLone, Carlie A.; Makynen, Elizabeth A.; Seidl, Sara M.; Thomas, Linnea M.; Villeneuve, Daniel L.; Weberg, Matthew A.; Wilson, Vickie S.; Ankley, Gerald T.

    2014-01-01

    Animal waste from livestock farming operations can contain varying levels of natural and synthetic androgens and/or estrogens, which can contaminate surrounding waterways. In the present study, surface stream water was collected from 6 basins containing livestock farming operations. Aqueous concentrations of 12 hormones were determined via chemical analyses. Relative androgenic and estrogenic activity was measured using in vitro cell assays (MDA-kb2 and T47D-Kbluc assays, respectively). In parallel, 48-h static-renewal in vivo exposures were conducted to examine potential endocrine-disrupting effects in fathead minnows. Mature fish were exposed to surface water dilutions (0%, 25%, 50%, and 100%) and 10-ng/L of 17α-ethynylestradiol or 50-ng/L of 17β-trenbolone as positive controls. Hepatic expression of vitellogenin and estrogen receptor α mRNA, gonadal ex vivo testosterone and 17β-estradiol production, and plasma vitellogenin concentrations were examined. Potentially estrogenic and androgenic steroids were detected at low nanogram per liter concentrations. In vitro estrogenic activity was detected in all samples, whereas androgenic activity was detected in only 1 sample. In vivo exposures to the surface water had no significant dose-dependent effect on any of the biological endpoints, with the exception of increased male testosterone production in 1 exposure. The present study, which combines analytical chemistry measurements, in vitro bioassays, and in vivo fish exposures, highlights the integrated value and future use of a combination of techniques to obtain a comprehensive characterization of an environmental chemical mixture. 

  16. Assessment of Types and Abundance of Live Food for Fish Farming ...

    African Journals Online (AJOL)

    Keywords: live food, rotifers, protozoa, phytoplankton, fertilisation, earthen ponds. Surveys of naturally-occurring live food for fish in Makoba earthen ponds, Zanzibar were conducted from November 2001 to August 2002. This involved identification of dominant plankton in the water column as well as the composition of algal ...

  17. Acid-base regulation in intensively farmed air-breathing fish

    DEFF Research Database (Denmark)

    Bayley, Mark; Damsgaard, Christian; Thomsen, Mikkel

    Hypercapnia in slow moving organically loaded tropical waters is a natural occurrence with several records of pCO2 at 60 mm Hg. Despite this, studies on South American air-breathing fish have revealed a low capacity for extracellular pH (pHe) regulation. The two underlying reasons proposed are; 1...

  18. Yersiniosis outbreak in rainbow trout at fish farm in Oromia Regional ...

    African Journals Online (AJOL)

    District, West Arsi Zone, Oromia Region of Ethiopia. The historical introduction and well survival of ... Meribo River in the district of Adaba located in West Arsi Administrative Zone of Oromia Region at 350 km from the ... At arrival, six of the fish were alive while one of them was dead. Ini- tial ante mortem examination was later ...

  19. Assessment of Types and Abundance of Live Food for Fish Farming ...

    African Journals Online (AJOL)

    Daisy Ouya

    Abstract—Surveys of naturally-occurring live food for fish in Makoba earthen ponds, Zanzibar were conducted from November 2001 to August 2002. This involved identification of dominant plankton in the water column as well as the composition of algal mats. The effect of nutrients on the composition and abundance of the ...

  20. A survey of wild marine fish identifies a potential origin of an outbreak of viral haemorrhagic septicaemia in wrasse, Labridae, used as cleaner fish on marine Atlantic salmon, Salmo salar L., farms.

    Science.gov (United States)

    Wallace, I S; Donald, K; Munro, L A; Murray, W; Pert, C C; Stagg, H; Hall, M; Bain, N

    2015-06-01

    Viral haemorrhagic septicaemia virus (VHSV) was isolated from five species of wrasse (Labridae) used as biological controls for parasitic sea lice predominantly, Lepeophtheirus salmonis (Krøyer, 1837), on marine Atlantic salmon, Salmo salar L., farms in Shetland. As part of the epidemiological investigation, 1400 wild marine fish were caught and screened in pools of 10 for VHSV using virus isolation. Eleven pools (8%) were confirmed VHSV positive from: grey gurnard, Eutrigla gurnardus L.; Atlantic herring, Clupea harengus L.; Norway pout, Trisopterus esmarkii (Nilsson); plaice, Pleuronectes platessa L.; sprat, Sprattus sprattus L. and whiting, Merlangius merlangus L. The isolation of VHSV from grey gurnard is the first documented report in this species. Nucleic acid sequencing of the partial nucleocapsid (N) and glycoprotein (G) genes was carried out for viral characterization. Sequence analysis confirmed that all wild isolates were genotype III the same as the wrasse and there was a close genetic similarity between the isolates from wild fish and wrasse on the farms. Infection from these local wild marine fish is the most likely source of VHSV isolated from wrasse on the fish farms. © 2014 Crown Copyright. Journal of Fish Diseases © 2014 John Wiley & Sons Ltd.

  1. Trichodina colisae (Ciliophora: Trichodinidae): new parasite records for two freshwater fish species farmed in Brazil.

    Science.gov (United States)

    Jerônimo, Gabriela Tomas; Marchiori, Natália da Costa; Pádua, Santiago Benites de; Dias Neto, José; Pilarski, Fabiana; Ishikawa, Márcia Mayumi; Martins, Maurício Laterça

    2012-01-01

    Family Trichodinidae comprises ciliate protozoa distributed worldwide; they are considered some of the main parasitological agents infecting cultivated fish. However, the trichodinidae parasitizing important fish species cultured in Brazil are unknown, and more taxonomic studies on this group of parasites are required. This research morphologically characterizes Trichodina colisae Asmat & Sultana, (2005) of pacu (Piaractus mesopotamicus) and patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in the central and southeast regions of the country. Fresh assemblies were made from mucus scraped from the skin, fins and gills, fixed with methanol and, subsequently, impregnated with silver nitrate and stained with Giemsa for assessment under light microscopy. This research reports not only the second occurrence of T. colisae in the world, but also its first occurrence in South America.

  2. BASIC PARAMETERS FOR DESIGNING PHYSICAL SEPARATION TREATMENTS FROM AN INTENSIVE ON-SHORE FISH FARM

    Directory of Open Access Journals (Sweden)

    Biagio Bianchi

    2012-06-01

    Full Text Available The pollutant load was monitored in an intensive on-shore plant; evaluation especially concerned one basin,during a period of time in which the water temperature (21-23°c, the stocking density (25 kg/m3, the loading and unloading flow (40 dm3/s remained steady at the highest values. The results show that the maximum pollution levels are characterized by high concentrations of suspended organic materials, as well as by high BOD5/COD rates; moreover, more than 60% of the suspended solid waste consists of particles with a maximum dimension ranging from 200 μm to more than 500 μm. Tests show that an effluent channel is not efficient in reducing the pollutant load of waste water. The laboratory sedimentation trials showed – for a period of about 3 hours – minimum and maximum solid particle sedimentation speeds of 2.56 mm/s and 46.8 mm/s respectively, which should be considered when deciding the turbid speed and the dimensions of basins for this type of effluent. In any case, the sedimentation process carried out in the laboratory was only just sufficient to bring the farm effluent within the legal limits. Therefore a mechanical filtration treatment may suit the specific requirements of the farm waste water used for the experimental trials. A 50 μm mesh would be considered sufficient for any critical situation.

  3. Mycoflora and mycotoxins in finished fish feed and feed ingredients from smallholder farms in East Africa

    Directory of Open Access Journals (Sweden)

    Esther Marijani

    2017-06-01

    Full Text Available A total of 52 samples of finished fish feeds and ingredients were collected from smallholder farmers in Kenya, Tanzania, Rwanda and Uganda, and analyzed. Culture and molecular techniques were used to identify fungal isolates from the feedstock, and mycotoxin profiles were determined using liquid chromatography–tandem mass spectrometry. The most prevalent fungal species recovered in the samples was Asperigillus flavus (54.5%. Other fungal species recovered from the samples were Aspergillus tamarii (9.1%, Mucor velutinosus (9%, Phoma sp. (6.1%, Aspergillus niger (6%, Eurotium rubrum (3% and Penicillium chrysogenum (3%. Fourteen mycotoxins were identified: aflatoxins B1, B2, G1 and G2, fumonisin B1 and B3, deoxynivalenol (DON and acetyldeoxynivalenol (sum of 3-ADONand 15-ADON, ochratoxin A, roquefortine C, alternariol, T-2 toxin, and nivalenol. DON (92.9%, aflatoxins (64.3% and fumonisins (57.1% were the most prevalent within locally manufactured feeds, while no contamination was found in imported feed. Samples from Kenya were the most contaminated with aflatoxin (maximum 806.9 μg·kg−1. The high levels of aflatoxin and trichothecene type A and B contamination found in this study point to potential risks to fish performance and to the health of consumers of the fish and derived products.

  4. MORPHOMETRIC CHARACTERISTICS OF THE REPLACEMENT-BROOD STOCK OF RAINBOW TROUT (ONCORHYNCHUS MYKISS (WALBAUM, 1792 REARED IN THE CONDITIONS OF THE INDUSTRIAL FISH FARM "SLOBODA-BANYLIV”

    Directory of Open Access Journals (Sweden)

    P. Mendrishora

    2017-09-01

    Full Text Available Purpose. To analyze the results of morphometric measurements and dates of aquaculture-biological characteristics of the young-of-the-year and age-1+ rainbow trout reared under industrial technology at instable conditions of the fish farm “Sloboda-Banyliv”. Methodology. The study has been performed at the industrial fish farm “Sloboda-Banyliv”, Chernivtsi region. The materials for the study were young-of-the-year and age-1+ rainbow trout obtained from the eggs of autumn-spawning form rainbow trout. The young-of-the-year were reared in a 216 m2 tank with stocking density of 255 ind./m2, age-1+ fish were reared in 108 m2 tank with a stocking density of 33 ind./m2 according to generally accepted methods in trout culture. Morphometric measurements of fish were performed according to I.F. Pravdin. Statistical processing of data was carried out in Microsoft Office Excel (2003. The analysis of values was done in the system of absolute values. The analyzed criteria of the measured parameters were their mean values and standard errors (M±m, deviation (σ, variability coefficient (Cv. Fish were fed with the artificial feed with high protein content manufactured by “Biomar” (Denmark. Findings. The studies on rainbow trout rearing under industrial conditions showed that fish body proportions did not change with age, however, the length of their fins decreased. The slenderness coefficient in age-1+ fish decreased insignificantly that is typical with increasing body depth. Despite instable rearing conditions, both young-of-the-year and age-1+ fish were characterized by moderate growth rate and high feed-conversion efficiency. Originality. For the first time, in conditions of Ukraine, a study on the formation of rainbow trout brood stocks in a fish farm with instable rearing conditions was performed with the use of the analysis of phenotypical and productive features. Practical value. The results of the performed work will provide an opportunity to

  5. Detecting the presence of fish farm-derived organic matter at the seafloor using stable isotope analysis of phospholipid fatty acids.

    Science.gov (United States)

    Mayor, Daniel J; Gray, Nia B; Hattich, Giannina S I; Thornton, Barry

    2017-07-11

    The expansion of global aquaculture activities is important for the wellbeing of future generations in terms of employment and food security. Rearing animals in open-exchange cages permits the release of organic wastes, some of which ultimately reaches the underlying sediments. The development of rapid, quantitative and objective monitoring techniques is therefore central to the environmentally sustainable growth of the aquaculture industry. Here, we demonstrate that fish farm-derived organic wastes can be readily detected at the seafloor by quantifying sediment phospholipid fatty acids (PLFAs) and their carbon stable isotope signatures. Observations across five farms reveal that farm size and/or distance away from it influence the spatial distribution of the generated organic wastes and their effect on benthic bacterial biomass. Comparison to the isotopic signatures of fish feed-derived PLFAs indicates that 16:0 and 18:1(n-9) are potential biomarkers for fish farm-derived organic wastes. Our results suggest that stable isotope analysis of sediment PLFAs has potential for monitoring the environmental performance of aquaculture activities, particularly given the increasing prevalence of terrigenous organic matter in aquaculture feed stocks because it is isotopically district to marine organic matter.

  6. Comparison of water, sediment, and plants for the monitoring of antibiotics: a case study on a river dedicated to fish farming.

    Science.gov (United States)

    Pouliquen, Hervé; Delépée, Raphaël; Thorin, Chantal; Haury, Jacques; Larhantec-Verdier, Michaëlle; Morvan, Marie-Line; Le Bris, Hervé

    2009-03-01

    Oxolinic acid, flumequine, oxytetracycline, and florfenicol are antibiotics commonly used in farming. Because an important percentage of these antibiotics given to fish and cattle ends up, directly or indirectly, in the freshwater environment, suitable tools for the monitoring of these antibiotics are needed. A French river was chosen because of the location of four fish farms and a sewage plant on its main course. First, a passive monitoring program involving water, sediment, and autochthonous bryophytes was performed at 25 sampling sites tested once every three months for one year. Second, an active monitoring method was performed using moss bags for a one-month exposure period, both upstream and downstream of each potential source of antibiotics. Sediment and bryophyte samples, but not water samples, were found to be useful for monitoring environmental contamination by oxolinic acid, flumequine, oxytetracycline, and florfenicol. Sediments and bryophytes also appeared to be complementary media for dating the river's contamination by antibiotics. Data collected by both active and passive monitoring methods confirmed contamination of the river, mainly by flumequine and oxytetracycline, attributable to fish farming but also to terrestrial animal farming and perhaps human pharmaceuticals.

  7. Application of nonparametric multivariate analyses to the authentication of wild and farmed European sea bass (Dicentrarchus labrax). Results of a survey on fish sampled in the retail trade.

    Science.gov (United States)

    Fasolato, Luca; Novelli, Enrico; Salmaso, Luigi; Corain, Livio; Camin, Federica; Perini, Matteo; Antonetti, Paolo; Balzan, Stefania

    2010-10-27

    The aim of this study was to apply biometric measurements and analyses of proximate composition, fatty acid composition, and ratios of stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) in muscle tissue to reliably differentiate between wild and farmed European sea bass (Dicentrarchus labrax). Farmed (n = 20) and wild (n = 19) European sea bass were purchased between March and May 2008 and used as standard samples. In the same months, a survey was conducted to evaluate the truthfulness of the statements on the labels of European sea bass sold in retail markets (declared farmed n = 34 and declared wild n = 33). In addition, data from the literature (reference) were employed to build the profile type of wild and farmed European sea bass. Primarily, an exploration and comparison of the analytical data of the standard data set based on principal component analysis and permutation test were performed. Afterward, an inferential statistical approach based on nonparametric combination test methodology (NPC) was applied on standard samples to check its suitability in discriminating the production method. This multivariate statistical analysis selected 30 variables on a total of 36 available. The validation of standard fish data set was accomplished by a novel nonparametric rank-based method according to profile type (just 1 misclassification over 39 samples). Both the NPC test and nonparametric rank-based method were then applied to survey fishes using the selected variables with the aim to classify the individual European sea bass as "true farmed" or "true wild". The former test segregated 10 fishes over 33 declared wild, whereas the results obtained by the nonparametric rank-based method showed that 11 of 33 declared wild European sea bass samples could be unquestionably attributed to the wild cluster. Moreover, considering the comparative contribution of profile type, a few surveyed farmed samples were ascribed to the wild cluster.

  8. How many fish in a tank? Constructing an automated fish counting system by using PTV analysis

    Science.gov (United States)

    Abe, S.; Takagi, T.; Takehara, K.; Kimura, N.; Hiraishi, T.; Komeyama, K.; Torisawa, S.; Asaumi, S.

    2017-02-01

    Because escape from a net cage and mortality are constant problems in fish farming, health control and management of facilities are important in aquaculture. In particular, the development of an accurate fish counting system has been strongly desired for the Pacific Bluefin tuna farming industry owing to the high market value of these fish. The current fish counting method, which involves human counting, results in poor accuracy; moreover, the method is cumbersome because the aquaculture net cage is so large that fish can only be counted when they move to another net cage. Therefore, we have developed an automated fish counting system by applying particle tracking velocimetry (PTV) analysis to a shoal of swimming fish inside a net cage. In essence, we treated the swimming fish as tracer particles and estimated the number of fish by analyzing the corresponding motion vectors. The proposed fish counting system comprises two main components: image processing and motion analysis, where the image-processing component abstracts the foreground and the motion analysis component traces the individual's motion. In this study, we developed a Region Extraction and Centroid Computation (RECC) method and a Kalman filter and Chi-square (KC) test for the two main components. To evaluate the efficiency of our method, we constructed a closed system, placed an underwater video camera with a spherical curved lens at the bottom of the tank, and recorded a 360° view of a swimming school of Japanese rice fish (Oryzias latipes). Our study showed that almost all fish could be abstracted by the RECC method and the motion vectors could be calculated by the KC test. The recognition rate was approximately 90% when more than 180 individuals were observed within the frame of the video camera. These results suggest that the presented method has potential application as a fish counting system for industrial aquaculture.

  9. Effects of changes in food supply at the time of sex differentiation on the gonadal transcriptome of juvenile fish. Implications for natural and farmed populations.

    Directory of Open Access Journals (Sweden)

    Noelia Díaz

    Full Text Available Food supply is a major factor influencing growth rates in animals. This has important implications for both natural and farmed fish populations, since food restriction may difficult reproduction. However, a study on the effects of food supply on the development of juvenile gonads has never been transcriptionally described in fish.This study investigated the consequences of growth on gonadal transcriptome of European sea bass in: 1 4-month-old sexually undifferentiated fish, comparing the gonads of fish with the highest vs. the lowest growth, to explore a possible link between transcriptome and future sex, and 2 testis from 11-month-old juveniles where growth had been manipulated through changes in food supply. The four groups used were: i sustained fast growth, ii sustained slow growth, iii accelerated growth, iv decelerated growth. The transcriptome of undifferentiated gonads was not drastically affected by initial natural differences in growth. Further, changes in the expression of genes associated with protein turnover were seen, favoring catabolism in slow-growing fish and anabolism in fast-growing fish. Moreover, while fast-growing fish took energy from glucose, as deduced from the pathways affected and the analysis of protein-protein interactions examined, in slow-growing fish lipid metabolism and gluconeogenesis was favored. Interestingly, the highest transcriptomic differences were found when forcing initially fast-growing fish to decelerate their growth, while accelerating growth of initially slow-growing fish resulted in full transcriptomic convergence with sustained fast-growing fish.Food availability during sex differentiation shapes the juvenile testis transcriptome, as evidenced by adaptations to different energy balances. Remarkably, this occurs in absence of major histological changes in the testis. Thus, fish are able to recover transcriptionally their testes if they are provided with enough food supply during sex

  10. A piscicultura e o ambiente: o uso de alimentos ambientalmente corretos em piscicultura Fish farming and the environment: the use of environmental friendly feeds in fish culture

    Directory of Open Access Journals (Sweden)

    José Eurico Possebon Cyrino

    2010-07-01

    Full Text Available Embora a ciência da nutrição de peixes esteja longe de estabelecer um padrão geral de exigências nutricionais, a necessidade de desenvolvimento de alimentos de baixo impacto poluente há muito faz parte da agenda das comunidades científica e empresarial internacional da aqüicultura. Não só é absolutamente possível formular alimentos ambientalmente corretos, como é necessário modelar a formulação destes alimentos. Porém, é necessária absoluta acurácia para atender formulações espécie-específicas, considerando-se as interações da biologia e fisiologia nutricional das espécies com os alimentos e com as variações abióticas do meio. O conhecimento disponível sobre as mais de 200 espécies de peixe produzidas comercialmente no mundo é ainda incipiente e os sistemas de produção de peixe, nos diferentes regimes de exploração, estão implantados em todas as condições ecológicas possíveis. Neste cenário, produzir rações ambientalmente corretas é, senão impossível, pelo menos muito difícil e depende da ação coordenada e positiva de produtores, indústria da alimentação, agências regulatórias, e instituições de ensino e pesquisa para definir os parâmetros necessários à consecução deste objetivo.Although fish nutrition science is far from establishing general standards of nutritional requirements, the need for developing low impact feeds has long been included in the agenda of aquaculture's international scientific and business communities of. Not only is absolutely possible to formulate environmental friendly feeds, as it is necessary modeling the formulation of these feeds. However, it is necessary higher accuracy to develop species-specific formulations, considering interactions of the biology and nutritional physiology of the species with the feedstuffs and variations of abiotic environment. The knowledge on more than 200 species of commercially farmed fish is still incipient and fish production

  11. Can multiple fish farms be integrated within a semi-enclosed bay without causing acute ecosystem degradation?

    Directory of Open Access Journals (Sweden)

    Kristian Puhr

    2017-07-01

    Full Text Available The current study explores the possibility that multiple fish farms (FFs containing sea bass (Dicentrarchus labrax and sea bream (Sparus aurata can be successfully integrated within a semi-enclosed bay in the Croatian Adriatic. The research focuses on determining principal environmental factors (EFs that control the integration and attempts to estimate their individual and synergic ability to influence deposition and removal of organic matter (OM and trace elements (TE from the system. The complexity of the designated tasks demanded a comprehensive number of various datasets and samples to be used in the analysis. The ADCP data revealed strong wind induced currents forming within the research domain resulting in high system flushing efficiency (3.5–6 days. The sediment samples from all stations contained relatively inert minerals which contributed to overall low OM and TE concentrations and very limited variability found across the entire bathymetric range. The thermal advection effect recorded at two stations was attributed to specific seabed topography and the hydrodynamic response formed during Maestral wind episodes. The results indicate that a successful integration of four FFs has taken place within the research site (semi enclosed bay, and that the key EFs responsible for its success are strong wind induced hydrodynamics, favorable seabed topography and sediment mineral composition. The synergy of the principal EFs that formed within the system was found to have an attenuating effect regarding FFs chemical influence (OM and TE and an amplifying one regarding spatial footprint which extended to ≈2000 m distance.

  12. Photobacterium toruni sp. nov., a bacterium isolated from diseased farmed fish.

    Science.gov (United States)

    Labella, Alejandro M; Arahal, David R; Lucena, Teresa; Manchado, Manuel; Castro, Dolores; Borrego, Juan J

    2017-11-01

    Three bacterial strains were isolated from liver and spleen of diseased farmed redbanded seabream (Pagrus auriga) in south-west Spain. Their partial 16S rRNA gene sequences clustered within those of the genus Photobacterium, showing high similarity (98.6-99.3 %) to the type strains of Photobacterium iliopiscarium, P. piscicola, P. kishitanii, P. aquimaris and P. phosphoreum. Multilocus sequence analysis using six housekeeping genes (gapA, topA, mreB, ftsZ, gyrB and 16S rRNA) confirmed the new strains as forming an independent branch with a bootstrap value of 100, likely to represent a novel species. To confirm this, we used whole genome sequencing and genomic analysis (ANIb, ANIm and in silico DNA-DNA hybridization) obtaining values well below the thresholds for species delineation. In addition, a phenotypic characterization was performed to support the description and differentiation of the novel strains from related taxa. Cells were Gram-stain-negative, motile bacilli, chemo-organotrophic and facultatively anaerobic. They fermented glucose, as well as galactose and d-mannose, without production of gas. Oxidase and catalase were positive. The predominant cellular fatty acids were C16 : 1ω7c/C16 : 1ω6c and C16  :  0. The predominant respiratory quinone (Q-8) and major polar lipids (phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol) were inferred from annotated genes in the genome of strain H01100410BT, which had a G+C content of 38.6 mol%. The results obtained demonstrate that the three strains represent a novel species, for which the name Photobacterium toruni sp. nov. is proposed. The type strain is H01100410BT (=CECT 9189T=LMG 29991T).

  13. PCR survey for Paramoeba perurans in fauna, environmental samples and fish associated with marine farming sites for Atlantic salmon (Salmo salar L.).

    Science.gov (United States)

    Hellebø, A; Stene, A; Aspehaug, V

    2017-05-01

    Amoebic gill disease (AGD) caused by the amoeba Paramoeba perurans is an increasing problem in Atlantic salmon aquaculture. In the present PCR survey, the focus was to identify reservoir species or environmental samples where P. perurans could be present throughout the year, regardless of the infection status in farmed Atlantic salmon. A total of 1200 samples were collected at or in the proximity to farming sites with AGD, or with history of AGD, and analysed for the presence of P. perurans. No results supported biofouling organisms, salmon lice, biofilm or sediment to maintain P. perurans. However, during clinical AGD in Atlantic salmon, the amoeba were detected in several samples, including water, biofilm, plankton, several filter feeders and wild fish. It is likely that some of these samples were positive as a result of the continuous exposure through water. Positive wild fish may contribute to the spread of P. perurans. Cleaner fish tested positive for P. perurans when salmon tested negative, indicating that they may withhold the amoeba longer than salmon. The results demonstrate the high infection pressure produced from an AGD-afflicted Atlantic salmon population and thus the importance of early intervention to reduce infection pressure and horizontal spread of P. perurans within farms. © 2016 John Wiley & Sons Ltd.

  14. Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru.

    Science.gov (United States)

    Langeland, Aubrey L; Hardin, Rebecca D; Neitzel, Richard L

    2017-03-14

    Artisanal and small-scale gold mining (ASGM) has been an important source of income for communities in the Madre de Dios River Basin in Peru for hundreds of years. However, in recent decades, the scale of ASGM activities in the region has increased dramatically, and exposures to a variety of occupational and environmental hazards related to ASGM, including mercury, are becoming more widespread. The aims of our study were to: (1) examine patterns in the total hair mercury level of human participants in several communities in the region and compare these results to the 2.2 µg/g total hair mercury level equivalent to the World Health Organization (WHO) Expert Committee of Food Additives (JECFA)'s Provisional Tolerable Weekly Intake (PTWI); and (2), to measure the mercury levels of paco ( Piaractus brachypomus ) fish raised in local aquaculture ponds, in order to compare these levels to the EPA Fish Tissue Residue Criterion of 0.3 µg Hg/g fish (wet weight). We collected hair samples from 80 participants in four communities (one control and three where ASGM activities occurred) in the region, and collected 111 samples from fish raised in 24 local aquaculture farms. We then analyzed the samples for total mercury. Total mercury levels in hair were statistically significantly higher in the mining communities than in the control community, and increased with increasing geodesic distance from the Madre de Dios headwaters, did not differ by sex, and frequently exceeded the reference level. Regression analyses indicated that higher hair mercury levels were associated with residence in ASGM communities. The analysis of paco fish samples found no samples that exceeded the EPA tissue residue criterion. Collectively, these results align with other recent studies showing that ASGM activities are associated with elevated human mercury exposure. The fish farmed through the relatively new process of aquaculture in ASGM areas appeared to have little potential to contribute to human

  15. Selection of candidate fish species for farming in the bay of Guaratuba, Brazil

    Directory of Open Access Journals (Sweden)

    Jean-Luc Bouchereau

    2000-01-01

    Full Text Available An inventory of the maximum length (ML reached by 57 species of fishes living in the mangrove of Guaratuba, Brazil, was undertaken with an aim to evaluate the relationship between the ecosystem and the size of individuals. For each of these species, the maximum length found in the region were compared with those available in existing literature. The majority of populations presented individuals whose length reached at least 40% than the known maximum length for the species, although only 19.3% were longer than 300mm in absolute value. Population of the other species were represented only by individuals either in their initial development phases, or reduced length as compared to the maximum length known elsewhere for the same species. In this mangrove, species having the largest relative size are generally those that had the smallest absolute length. Proposed is use of an index LR (maximum observed lengths/maximum available lengths as a tool for description and comparison of fish assemblages. Observations of the maximum size make possible the pre-selection of 12 species for breeding tests. In combining the biological, technical and commercial parameters, the pre-selection retains as primordial the following species: Centropomus parallelus, Centropomus undecimalis, Menticirrhus americanus and Micropogonias furnieri.Realizou-se um inventário do comprimento máximo alcançado por 57 espécies de peixes no manguezal de Guaratuba, Brasil, objetivando caracterizar este ecossistema quanto ao tamanho dos indivíduos que acolhe. Para cada espécie, o comprimento máximo no manguezal foi comparado com aquele disponível na literatura, referente a outras populações da mesma espécie. Constatou-se que, na maioria das populações de Guaratuba, os indivíduos atingem pelo menos 40% do tamanho máximo conhecido para a espécie, embora em apenas 19,3% das populações o comprimento ultrapasse 300mm em valor absoluto. As outras espécies estão representadas

  16. Fish parasites

    DEFF Research Database (Denmark)

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  17. Effect of replacement of fish oil with camelina (Camelina sativa) oil on growth, lipid class and fatty acid composition of farmed juvenile Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Hixson, Stefanie M; Parrish, Christopher C; Anderson, Derek M

    2013-12-01

    Camelina (Camelina sativa) oil was tested as a replacement for fish oil in diets for farmed Atlantic cod (Gadus morhua). Camelina differs from other plant oilseeds previously used in aquaculture with high lipid (40 %), α-linolenic acid (40 %), antioxidants and low proportions of saturated fats. Dietary treatments were fed to cod (19 g fish⁻¹ initial weight) for 9 weeks and included a fish oil control (FO), 40 % (CO40) and 80 % (CO80) replacement of fish oil with camelina oil. There was no effect of replacing fish oil with camelina oil included at levels up to 80 % on the growth performance. Cod fed CO80 stored more lipid in the liver (p CO40 > CO80; p Camelina oil can reduce the amount of fish oil needed to meet lipid requirements, although replacing 80 % of fish oil reduced LC PUFAs in both tissues. A comparison of BF₃ and H₂SO₄ as catalysts to transmethylate cod liver and muscle lipids revealed small but significant differences in some fatty acid proportions.

  18. Offshore wind farms as productive sites or ecological traps for gadoid fishes?--impact on growth, condition index and diet composition.

    Science.gov (United States)

    Reubens, Jan T; Vandendriessche, Sofie; Zenner, Annemie N; Degraer, Steven; Vincx, Magda

    2013-09-01

    With the construction of wind farms all across the North Sea, numerous artificial reefs are created. These windmill artificial reefs (WARs) harbour high abundances of fish species which can be attracted from elsewhere or can be the result of extra production induced by these wind farms. To resolve the attraction-production debate in suddenly altered ecosystems (cf. wind farms), the possible consequences of attraction should be assessed; thereby bearing in mind that ecological traps may arise. In this paper we investigated whether the wind farms in the Belgian part of the North Sea act as ecological traps for pouting and Atlantic cod. Length-at-age, condition and diet composition of fish present at the windmill artificial reefs was compared to local and regional sandy areas. Fish data from the period 2009-2012 were evaluated. Mainly I- and II-group Atlantic cod were present around the WARs; while the 0- and I-group dominated for pouting. For Atlantic cod, no differences in length were observed between sites, indicating that fitness was comparable at the WARs and in sandy areas. No significant differences in condition index were observed for pouting. At the WARs, they were slightly larger and stomach fullness was enhanced compared to the surrounding sandy areas. Also diet differed considerably among the sites. The outcome of the proxies indicate that fitness of pouting was slightly enhanced compared to the surrounding sandy areas. No evidence was obtained supporting the hypothesis that the WARs act as an ecological trap for Atlantic cod and pouting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Water and Soil Analyses of Balongis Fish Cage and Oster (Talaba Farms in Concepcion River, Kabasalan, Zamboanga Sibugay Province, Philippines

    Directory of Open Access Journals (Sweden)

    Victoria L. Lim

    2017-02-01

    Full Text Available The decline of the talaba (saccosrea malabonensis production in Barangay Concepcion, Kabasalan, Zamboanga Sibugay motivated the fisher folks to determine the cause of the phenomenon through the Social Action Ministry (SAM – Diocese of Ipil, Ipil, Zamboanga Sibugay,Philippines who arranged for the conduct of the study. The research was hypothesized to be caused by climate change. Data collection began on January 28 until February 8, 2012 on site. Twelve (12 sampling sites were installed in Concepcion River barangay Balongis, Buayan Zamboanga Sibugay where the barangay’s fish cage and oyster (Talaba farms are Global Positioning System (GPS gadget was used for the identification/markings of sampling stations (07⁰ 46.00 N and 122⁰47.116E to 07⁰45.778 N and 122⁰47.151 E Water and soil/sediment samples were taken and analyzed once a week for three consecutive weeks – January 28 to February 18, 2012. Physical water parameters were taken in situ (pH, Temperature, salinity and TSS. Water temperature raging 24⁰C-31.5⁰C, water pH 7.0-8.24, water salinity 18 -27.6 ppt. Total Suspended Solids (TSS ranged 0.104 g/L to 0.672 g/L – classified turbid water for all sampling sites. Sediment analysis: for mercury containment – qualitative analysis is negative, Soil Classification using the Textual triangle – soil classified as Loamy Sand (Sites 7-10 and Sandy Loam for all other sites. Meiofauna component using the Nematoma, turbellaria, Ciliophora, Ostracoda, Gastrotricha, Tardigrada, Sarcomastigaphora, Sincarida, Copepoda and some other unidentified fauna. Sedimentation rate averaged from 1410-6469 g/m2 per week. The high sediment rate could have caused the decline in oyster production but not by mercury contamination as suspected.

  20. Fish and Meat Are Often Withheld From the Diets of Infants 6 to 12 Months in Fish-Farming Households in Rural Bangladesh.

    Science.gov (United States)

    Thorne-Lyman, Andrew L; Valpiani, Natalie; Akter, Rumana; Baten, Md Abdul; Genschick, Sven; Karim, Manjurul; Thilsted, Shakuntala H

    2017-09-01

    Fish is a widely available animal-source food in Bangladesh and a rich source of nutrients, yet little is known about practices related to incorporating fish into the diets of infants and young children. Use dietary diversity data to explore consumption patterns of fish and high-quality food items within the household and examine factors associated with delayed introduction of fish to infants and young children. Cross-sectional survey of 496 households with children Meat and fish were not common in infant diets but increased with child age. Concerns about bones were a major barrier to incorporating fish into infant diets. Given its nutrient profile and widespread availability in certain contexts, fish could be an underutilized opportunity to improve nutrition and health outcomes of infants and young children. Further research, including utilizing food processing technologies, is needed to develop appropriate responses to overcome these barriers.

  1. MORTALITY OF YOUTH Arapaima gigas (PISCES: ARAPAIMIDAE FROM A FISH FARMING IN THE NORTH OF BRAZIL, CAUSED BY Hysterothylacium sp. AND Goezia spinulosa (NEMATODA: ANISAKIDAE

    Directory of Open Access Journals (Sweden)

    Patrizia Batista de Azevedo

    2017-03-01

    Full Text Available In youth A. gigas the risk of parasitic infections is very high, due to their feeding habit to prey on small invertebrates, which act as intermediate hosts of different endoparasite species, which can cause serious problems and high mortalities in fish farms. Thus, the aim of the present study was to identify the species that parasitize youth A. gigas raised in captivity in the Manacapuru municipality, Amazonas State and to evaluate their influence on the mortality of these fish. There were examined 66 youth A. gigas and non-parasite was recorded in the host gills. The intestine and stomach of the fish were parasitized by Hysterothylacium sp. larvae (L3 and Goezia spinulosa larvae (L4. The parasitic indexes were high for the two species, being recorded the highest rates of infection by Hysterothylacium sp. There was observed a weak positive correlation between the host standard length and the abundance of Hysterothylacium sp. The lesions observed in the stomach and intestine of the fish, together with the high parasite index values recorded for Hysterothylacium sp. and Goezia spinulosa, leads to the suspicion that the death of the fish was due to complications and damages caused by the presence of these parasites. Keywords: Amazonia; arapaima; death; nematodes.

  2. The role of a fish pond in optimizing nutrient flows in integrated agriculture-aquaculture farming systems

    NARCIS (Netherlands)

    Nhan, D.K.

    2007-01-01

      In the Mekong delta, the Vietnamese government promoted integrated agriculture-aquaculture (IAA) farming systems as an example of sustainable agriculture. An important advantage of IAA-farming is the nutrient linkage between the pond and terrestrial components within a

  3. The impact of a freshwater fish farm on the community of tetracycline-resistant bacteria and the structure of tetracycline resistance genes in river water.

    Science.gov (United States)

    Harnisz, Monika; Korzeniewska, Ewa; Gołaś, Iwona

    2015-06-01

    The aim of this study was to assess the impact of a fish farm on the structure of antibiotic resistant bacteria and antibiotic resistance genes in water of Drwęca River. Samples of upstream river waters; post-production waters and treated post-production waters from fish farm; as well as downstream river waters were monitored for tetracycline resistant bacteria, tetracycline resistant genes, basic physico-chemical parameters and tetracyclines concentration. The river waters was characterized by low levels of pollution, which was determined based on water temperature, pH and concentrations of dissolved oxygen and tetracycline antibiotics. Culture-dependent (heterotrophic plate counts, counts of bacteria resistant to oxytetracycline (OTC(R)) and doxycycline (DOX(R)), minimum inhibitory concentrations for oxytetracycline and doxycycline, multidrug resistance of OTC(R) and DOX(R), qualitative composition of OTC(R) and DOX(R), prevalence of tet genes in resistant isolates) and culture-independent surveys (quantity of tet gene copies) revealed no significant differences in the abundance of antibiotic-resistant bacteria and antibiotic resistance genes between the studied samples. The only way in which the fish farm influenced water quality in the Drwęca River was by increasing the diversity of tetracycline-resistance genes. However, it should also be noted that the bacteria of the genera Aeromonas sp. and Acinetobacter sp. were able to transfer 6 out of 13 tested tet genes into Escherichiacoli, which can promote the spread of antibiotic resistance in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Local Knowledge of Pond Fish-Farming Ecosystem Services: Management Implications of Stakeholders’ Perceptions in Three Different Contexts (Brazil, France and Indonesia

    Directory of Open Access Journals (Sweden)

    Syndhia Mathé

    2015-06-01

    Full Text Available This article addresses ecosystem service perceptions in the case of pond fish-farming systems in Brazil, France and Indonesia. The Millennium Ecosystem Assessment vision suggests a more integrated reflection on environmental policies with greater adaptability to local knowledge and the development of social learning processes, which tend to promote more sustainable changes in behavior and practice than do sanctions. This study considers a part of the identification of ecosystem services. It shows that perceptions differ with the context, and found few differences depending on the type of stakeholders (fish farmers and other stakeholders. From a methodological viewpoint, this paper opens up new prospects for valuing ecosystem services through a perception study.

  5. Effects of marine wind farms on the distribution of fish, shellfish and marine mammals in the Horns Rev area

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, E.; Astrup, J.; Larsen, Finn; Munch-Petersen, S.

    2000-05-15

    The purpose of the report is: 1) to give a quantitative description of the abundance of the fish and shellfish in the area surrounding the windmill area and to evaluate the effects of the physically presence of the windmills on the abundance of fish and shellfish in the area; 2) to evaluate the artificial reef effect in the windmill area; 3) to evaluate the effects of noise and electromagnetic fields on the abundance of fish and marine mammals. (au)

  6. Designing an integrated environmental monitoring plan for land-based marine fish farms located at exposed and hard bottom coastal areas.

    Science.gov (United States)

    Carballeira, C; Ramos-Gómez, J; Martín-Díaz, M L; DelValls, T A; Carballeira, A

    2012-05-01

    The increase in aquaculture activities in the last few decades has not been accompanied by a corresponding increase in environmental controls and regulations. In this context, the application of environmental monitoring plans (EMPs) has become necessary to assess the environmental impact associated with fish farming wastes. The objective of this review paper is to evaluate the suitability of experimental and analytical procedures as monitoring tools for inclusion in EMPs for intensive land-based marine fish farms (LBMFFs). The strong hydrodynamics and, in particular, the lack of sediment on the rocky coasts where LBMFFs are usually located, greatly limit the monitoring tools that can be used. We propose EMPs that employ a weight-of-evidence approach to evaluate: contamination, trophic and toxic effects, and ecological integrity. Laboratory tests, in situ bioassays and field surveys of local species are presented as key tools for assessing the impact of LBMFFs on ecosystems. The δ(15)N signal along a spatial gradient is proposed for evaluating exposure to contaminants. Trophic effects can be determined by growth of transplanted macro- and microalgae. Toxic effects can be evaluated by responses at different levels of biological organization, including biochemical and histological changes, physiological alterations and survival, in species from different trophic levels. Fouling tests and analysis of community structures are recommended for assessing ecological integrity. This review contributes to the development of environmental controls for intensive LBMFFs, and for other activities that discharge wastewater to rocky shores.

  7. EVALUATION OF FISH FAUNA STOCKS IN DAMS IN SOSSEGO MIME IN CANAÃ OF CARAJÁS (EASTERN AMAZON, CAPTURED WITH THE USE OF CAST NET BEFORE THE DEPOSIT OF TAILINGS

    Directory of Open Access Journals (Sweden)

    Ivan Furtado Junior

    2016-12-01

    Full Text Available This study aims to estimate the biomass of fish stocks in the area of the dam formed by tailings of Sossego mine in Canaã dos Carajás, captured with the use of cast nets for fish. The prospecting work was carried out during the period from 29 February to 6 March 2004, 6 months after closing the dam and immediately before the disposal of waste. The average values estimated for the capture per unit area covered by cast nets (CPUA and biomass were 8.4 g m-² and 16,922.7 kg, respectively. The most representative groups of fish were minnows, with 67.7% and discus with 24.8% of the total estimated biomass. The species caught were: Moenkhausia cf. sanctaefilomenae (redeye tetra fish, Tetragonopterus cf. argenteus (white tetra fish, Tetragonopterus chalceus (red tetra fish, Aequidens viridis (cichlasoma bimaculatum Crenicichla cincta (jacunda Hoplerythrinus unitaeniatus (jeju Curimata inornata (branquinha and Hoplias malabaricus (trahira. Keywords: fishing survey; yield per unit area; biomass; tailings dam.

  8. Caracterização da piscicultura na região do Vale do Ribeira - SP Characterization of fish farming in the Ribeira Valley region - SP

    Directory of Open Access Journals (Sweden)

    Daniela Castellani

    2005-02-01

    Full Text Available Este trabalho buscou caracterizar a piscicultura na Região do Vale do Ribeira quanto aos sistemas de manejo. Estudaram-se quarenta e duas pisciculturas sendo que, destas, 36 praticam o sistema semi-intensivo e seis o sistema intensivo, com os seguintes objetivos: engorda de peixes, produção de alevinos e pesque-pagues. Foram listadas 41 espécies de peixes cultivadas. Apenas 6 espécies são nativas da Bacia do Rio Ribeira de Iguape: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier e Valenciennes, 1928, jundiá (Rhamdia quelen Quoy e Gaimard, 1824, cascudo (Hypostomus sp Marschall, 1873 e cará (Geophagus brasiliensis Quoy e Gaimard, 1824. Em 95% das pisciculturas foram verificadas fugas de peixes exóticos e alóctones dos cultivos. A tilápia nilótica (Oreochromis niloticus Linneaus, 1758 foi a espécie mais freqüente em escapes, e também é a segunda mais cultivada pelos piscicultores, perdendo somente para o pacu (Piaractus mesopotamicus Halmberg, 1887. Foi possível verificar mediante o cálculo da conversão alimentar, que há um desperdício anual de cerca de 32% da ração utilizada nos cultivos pesquisados. A piscicultura encontra-se em plena expansão nesta região, e já representa a atividade agropecuária mais importante após a bananicultura.The aim of this work was to characterize the fish farming in the Ribeira de Iguape Basin, southern São Paulo State (Brazil, in relation to the management systems. Forty two farms were studied. A semi-intensive system is used by 36 farmers, while an intensive system is used only by 6 studied farmers. Their objectives were raising fish, juvenile fish production and sportive fishery. Forty one fish species were found to be cultivated, but only six were native species from Ribeira Valley: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier and Valenciennes, 1928, jundi

  9. Stable isotopes as a useful tool for revealing the environmental fate and trophic effect of open-sea-cage fish farm wastes on marine benthic organisms with different feeding guilds.

    Science.gov (United States)

    Wai, Tak-Cheung; Leung, Kenneth M Y; Wu, Rudolf S S; Shin, Paul K S; Cheung, S G; Li, X Y; Lee, Joseph H W

    2011-01-01

    Environmental fate of fish farm wastes (FFW) released from an open-sea-cage farm at Kat O, Hong Kong was examined by measuring carbon and nitrogen stable isotope (SI) ratios in selected benthic organisms collected along a 2000 m transect from the farm. Our results showed that FFW significantly influenced the energy utilization profile of consumers near the fish farm. Although nitrogen enrichment effect on δ15N was anticipated in biota near the farm, the predicted patterns did not consistently occur in all feeding guilds. Two species of suspension-feeders, which relied on naturally δ15N-depleted sources, were δ15N-enriched near the fish farm. In contrast, both species of benthic grazer and deposit-feeder, which relied on naturally δ15N-enriched algal sources, were δ15N-depleted under the influence of FFW. The SI signatures of biota can, therefore, serve as feasible biomarkers for FFW discharges only when the trophic structure of the receiving environment is fully elucidated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Analysis of Goat Farming on Integrated Farming System in Banyumas

    OpenAIRE

    NN Hidayat

    2007-01-01

    The objective of this research were : 1) to find out the income generated from goat farming and its contribution to farmer income in several farming combination, 2) to find out the economic efficiency in goat farming with paddy and fish production, 3) to determine factors affecting level of production and income in different farming system, partially and aggregately, and 4) to determine the best combination of farming which generated maximum income. Household farmer survey method was performe...

  11. Sound from wind farms in the ocean and its impact on fish; Ljud fraan vindkraftverk i havet och dess paaverkan paa fisk

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Mathias H.; Sigray, Peter (Stockholm univ. (Sweden); FOI Swedish Defence Research Agency, Stockholm (Sweden)); Persson, Leif K. G. (FOI Swedish Defence Research Agency, Stockholm (Sweden))

    2011-07-01

    For several years, commercial ship traffic has had the largest contribution of anthropogenic sound to the marine environment. Construction and operation of offshore wind farms adds new noise to the marine environment and so far, we know little about how this affects fish. This study aims to extend our knowledge of what kind of sound and the sound levels a wind farm generates during different wind speeds. Sound levels from an individual turbine and the whole wind farm are compared as well as other noise sources from the Oeresund area, such as commercial ships. Furthermore, the study describes the potential impact on fish from the sound generated by a wind farm during production. The study was conducted in the Oeresund at Lillgrund wind farm, built in 2007 and consists of 48 turbines (Siemens Mk II) with an individual power of 2,3 MW. The park is owned and operated by Vattenfall. Two hydrophone systems, one battery powered and one connected to the electricity grid in a turbine, was used during the measurement period. Measurements were carried out at different distances to individual turbines as well at some distance away from the whole park and in a control area (Sjollen) 10 km north of the park. To correctly estimate the entire park's contribution to the Oeresund soundscape, a numerical model of the park were developed where operational efficiency is varied. In addition, a numerical shipping model was developed to compare the ship-generated noise from the nearby shipping lane Flintraennan with wind park's sound. The results show that wind turbines produce a broadband noise below 1 kHz, and a pair of tones in which 127 Hz tone is the strongest. The maximum estimated noise levels that wind turbines generate were 136 and 138 dB re 1muPa{sub (RMS)} at one meter at full power (12 m/s) for the dominant 127 Hz (integrated over 123-132 Hz) tone and the full spectrum ( integrated over 52-343 Hz), respectively. This noise level is between 33-55 dB above ambient

  12. Fish welfare assurance system: initial steps to set up an effective tool to safeguard and monitor farmed fish welfare at a company level

    NARCIS (Netherlands)

    Vis, van de J.W.; Poelman, M.; Lambooij, E.; Bégout, M.L.; Pilarczyk, M.

    2012-01-01

    The objective was to take a first step in the development of a process-oriented quality assurance (QA) system for monitoring and safeguarding of fish welfare at a company level. A process-oriented approach is focused on preventing hazards and involves establishment of critical steps in a process

  13. Full substitution of fish oil with camelina (Camelina sativa) oil, with partial substitution of fish meal with camelina meal, in diets for farmed Atlantic salmon (Salmo salar) and its effect on tissue lipids and sensory quality.

    Science.gov (United States)

    Hixson, Stefanie M; Parrish, Christopher C; Anderson, Derek M

    2014-08-15

    Camelina oil (CO) and meal (CM) are potential replacements of fish meal (FM) and oil (FO) in aquaculture feeds. CO is high in α-linolenic acid (18:3ω3, ALA) (30%), with an ω3/ω6 ratio >1. This study tested diets with 100% CO, solvent extracted FM (SEFM) and partially substituted FM with 10% CM, in a 16 week feeding trial with Atlantic salmon (initial weight 240 g fish(-1)). Final weight (529-691 g fish(-1)) was not affected by using 100% CO; however it was lower in groups fed SEFM and 10% CM diets. Total lipid in salmon flesh fed a diet with CO, SEFM and CM (22% ww(-1)) was significantly higher than FO flesh (14% ww(-1)). There was no difference in the sensory quality of salmon fillets that were fed either FO or 100% CO diets. This was the first study to use CO as a complete FO replacement in diets for farmed Atlantic salmon. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. New species for the biomitigation of a super-intensive marine fish farm effluent: Combined use of polychaete-assisted sand filters and halophyte aquaponics.

    Science.gov (United States)

    Marques, Bruna; Calado, Ricardo; Lillebø, Ana I

    2017-12-01

    The main objective of this study was to test an innovative biomitigation approach, where polychaete-assisted (Hediste diversicolor) sand filters were combined with the production of Halimione portulacoides in aquaponics, to remediate an organic-rich effluent generated by a super intensive fish farm operating a land-based RAS (Recirculating aquaculture system). The set up included four different experimental combinations that were periodically monitored for 5months. After this period, polychaete-assisted sand filters reduced in 70% the percentage of OM and the average densities increased from ≈400ind.m(-2) to 7000ind.m(-2). H. portulacoides in aquaponics contributed to an average DIN (Dissolved inorganic Nitrogen) decrease of 65%, which increased to 67% when preceded by filter tanks stocked with polychaetes. From May until October (5months) halophytes biomass increased from 1.4kgm(-2)±0.7 (initial wet weight) to 18.6kgm(-2)±4.0. Bearing in mind that the uptake of carbon is mostly via photosynthesis and not though the uptake of dissolved inorganic carbon, this represents an approximate incorporation of ≈1.3kgm(-2) carbon (C), ≈15gm(-2) nitrogen (N) and ≈8gm(-2) phosphorus (P) in the aerial part (76% of total biomass), and an approximate incorporation of ≈0.5kgm(-2) carbon (C), ≈3gm(-2) nitrogen (N) and ≈2gm(-2) phosphorus (P) in the roots (24% of total biomass). In the present study, the potential of the two extractive species for biomitigation of a super-intensive marine fish farm effluent could be clearly demonstrated, contributing in this way to potentiate the implementation of more sustainable practices. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A Modelling Framework for Assessing the Risk of Emerging Diseases Associated with the Use of Cleaner Fish to Control Parasitic Sea Lice on Salmon Farms.

    Science.gov (United States)

    Murray, A G

    2016-04-01

    Sea lice are the most damaging parasite of marine salmonids, both economically and in terms of potential impacts on wild fish. An increasingly widely applied control is the use of cleaner fish (CF) such as wrasse that eat lice. However, such CF can carry pathogens that may cause disease in salmon, including the potential emergence of new diseases. This is not just a theoretical risk, as demonstrated by a recent outbreak of viral haemorrhagic septicaemia in wrasse held on salmon farms in Shetland. A modelling framework is developed to identify conditions in which emergence might occur, and, from this, means of reducing risk. Diseases that might emerge easily in farmed salmon would be likely to have already done so by other routes of exposure, and if risks are very low, they would need to be greatly enhanced to become significant relative to costs of lice control. CF may most enhance risks from disease with moderate probability of emerging. Risks of emergence can be reduced by replacing wild-caught with hatchery-reared CF, minimizing mixing of CF from different sources, surveillance for clinical disease in the CF and ensuring strategic biosecurity (area management with synchronized fallowing). Reuse of CF for a second salmon production cycle may reduce costs and even probability of infection (especially from wild-caught CF), but should only be considered as part of a rigorous area management programme because the practice presents opportunities for pathogens to adapt to salmon by weakening fallowing. © 2014 Crown copyright. This article is published with the permission of the Controller of HMSO/the Queen's Printer for Scotland and Marine Scotland Science.

  16. Genetic considerations on the introduction of farmed fish in marine protected areas: The case of study of white seabream restocking in the Gulf of Castellammare (Southern Tyrrhenian Sea)

    Science.gov (United States)

    González-Wangüemert, Mercedes; Fernández, Tomás Vega; Pérez-Ruzafa, Angel; Giacalone, Maximiliano; D'Anna, Giovanni; Badalamenti, Fabio

    2012-02-01

    Human exploitation has drastically reduced the abundance and distribution of several marine fish and invertebrate populations through overfishing and habitat destruction. Restocking can potentially mitigate these impacts and help to reconstitute depleted stocks but genetic repercussions must be considered. In the present study, the degree of genetic similarity between white seabream (Diplodus sargus Linnaeus 1758) individuals reared for restocking purposes and the receiving population in the Gulf of Castellammare fishery reserve (Sicily, Italy) was assessed using microsatellites. We also inferred the spatial pattern of the genetic structure of D. sargus and connectivity along Sicilian coasts. The farmed population showed significant heterozygosity deficiency in 6 loci and an important reduction in the number of alleles, which could indicate an incipient inbreeding. Both the farmed population and the target one for restocking (Castellammare fishery reserve), showed high and significant values of genetic differentiation due to different allele frequencies, number of privative alleles and total number of alleles. These findings indicate a low degree of genetic similarity between both populations, therefore this restocking initiative is not advisable. The genetic connectivity pattern, highly consistent with oceanographic currents, identified two distinct metapopulations of white seabream around Sicily. Thus it is recommended to utilize broods from the same metapopulation for restocking purposes to provide a better genetic match to the wild populations.

  17. Evaluation nutritional of acid silage of Nile tilapia (Oreochromis niloticus), whole fish discarded, farmed in Indaiatuba – SP

    OpenAIRE

    Sales, Ronaldo de Oliveira; Universidade Federal do Ceará; Oliveira, Admar Costa de; Universidade Estadual de Campinas - UNICAMP - S.P.

    2013-01-01

    The continental aquaculture with a production of  210,644,500  thousand tonnes produces a volume of solid waste causing a serious environmental problem, where 20% of the fish caught gets lost for lack of storage. The ideal would be to use raw materials and to recover byproducts as ingredients for animal feed. Aiming to increase the income and the capacity of production and, thus, to minimize environmental and health problems, deriving from fish waste, it was prepared the acid silage of the wh...

  18. Detection of dwarf gourami iridovirus (Infectious spleen and kidney necrosis virus) in populations of ornamental fish prior to and after importation into Australia, with the first evidence of infection in domestically farmed Platy (Xiphophorus maculatus).

    Science.gov (United States)

    Rimmer, Anneke E; Becker, Joy A; Tweedie, Alison; Lintermans, Mark; Landos, Matthew; Stephens, Fran; Whittington, Richard J

    2015-11-01

    The movement of ornamental fish through international trade is a major factor for the transboundary spread of pathogens. In Australia, ornamental fish which may carry dwarf gourami iridovirus (DGIV), a strain of Infectious spleen and kidney necrosis virus (ISKNV), have been identified as a biosecurity risk despite relatively stringent import quarantine measures being applied. In order to gain knowledge of the potential for DGIV to enter Australia, imported ornamental fish were sampled prior to entering quarantine, during quarantine, and post quarantine from wholesalers and aquatic retail outlets in Australia. Samples were tested by quantitative polymerase chain reaction (qPCR) for the presence of megalocytivirus. Farmed and wild ornamental fish were also tested. Megalocytivirus was detected in ten of fourteen species or varieties of ornamental fish. Out of the 2086 imported gourami tested prior to entering quarantine, megalocytivirus was detected in 18.7% of fish and out of the 51 moribund/dead ornamental fish tested during the quarantine period, 68.6% were positive for megalocytivirus. Of fish from Australian wholesalers and aquatic retail outlets 14.5% and 21.9%, respectively, were positive. Out of 365 farmed ornamental fish, ISKNV-like megalocytivirus was detected in 1.1%; these were Platy (Xiphophorus maculatus). Megalocytivirus was not detected in free-living breeding populations of Blue gourami (Trichopodus trichopterus) caught in Queensland. This study showed that imported ornamental fish are vectors for DGIV and it was used to support an import risk analysis completed by the Australian Department of Agriculture. Subsequently, the national biosecurity policy was revised and from 1 March 2016, a health certification is required for susceptible families of fish to be free of this virus prior to importation. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  19. The emerging farmed fish species meagre (Argyrosomus regius): how culinary treatment affects nutrients and contaminants concentration and associated benefit-risk balance.

    Science.gov (United States)

    Costa, Sara; Afonso, Cláudia; Bandarra, Narcisa Maria; Gueifão, Sandra; Castanheira, Isabel; Carvalho, Maria Luísa; Cardoso, Carlos; Nunes, Maria Leonor

    2013-10-01

    The effect of cooking methods (boiling, grilling, and roasting) on the proximate and mineral composition, contaminants concentration and fatty acids profile was evaluated aiming to understand the benefits and risks associated to the consumption of the emerging farmed fish meagre (Argyrosomus regius). All the treatments led to lower moisture content. After grilling and roasting, the SFA, MUFA and PUFA contents increased. There was no degradation of EPA and DHA during the culinary processes. Significant retention of minerals in grilled and roasted meagre samples was registered. For Pb and Cd there were no concentration differences between culinary treatments and regarding raw fish. Whereas As level was higher in grilled meagre, total Hg and Me-Hg values were augmented in grilled and roasted meagre. The consumption of meagre is advisable due to the low and healthy fat, high selenium and protein content. Grilling would be the best culinary treatment due to the retention of protein, EPA, DHA and minerals. But as the risk of ingestion of Me-Hg content also increases, based on the risk assessment, intake should not exceed two weekly meals, provided that no other important Me-Hg food source is present in the diet. Otherwise, even this maximum threshold should be lower. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Analysis of Goat Farming on Integrated Farming System in Banyumas

    Directory of Open Access Journals (Sweden)

    NN Hidayat

    2007-05-01

    Full Text Available The objective of this research were : 1 to find out the income generated from goat farming and its contribution to farmer income in several farming combination, 2 to find out the economic efficiency in goat farming with paddy and fish production, 3 to determine factors affecting level of production and income in different farming system, partially and aggregately, and 4 to determine the best combination of farming which generated maximum income. Household farmer survey method was performed to conduct this research. Farming model chosen in this research was partial and average aggregate. Cobb-Douglas function were chosen to predict functional relationship. Result stated from this research were : 1 goat farming has a significant contribution in integrated farming system, 2 integrated farming (goat and paddy, goat and fish, and goat, fish and paddy in Banyumas district was economically efficient. 3 partially, factor affecting production level in goat farming was number of goat owned (P<0.01, factor affecting paddy production were urea application and number of land owned (P<0.01, TSP application (P<0.05 and man power (P<0.10. Furthermore, factor affecting fish farming were feed, breed and number of land owned (P<0.01; 4 aggregately, factor affecting integrated farming I were urea application and number of land owned (P<0.01, feed and number of land owned (P<0.01, number of goat owned (P<0.10 integrated farming II, where as in integrated farming III were number of paddy land area and breed (P<0.01 also number of goat owned (P<0.10; 5 integrated farming III (goat, paddy and fish farming gave the highest profit, which gave Rp 6.219.283,81 with relatively high efficiency. Therefore, goat farming could be an alternative solution to be developed in integrated farming and could be combined with other farming activities such as paddy and fish farming. (Animal Production 9(2: 105-110 (2007 Key Words : Goat, income, economic efficiency, survey, contribution

  1. Farming behaviour of reef fishes increases the prevalence of coral disease associated microbes and black band disease.

    Science.gov (United States)

    Casey, Jordan M; Ainsworth, Tracy D; Choat, J Howard; Connolly, Sean R

    2014-08-07

    Microbial community structure on coral reefs is strongly influenced by coral-algae interactions; however, the extent to which this influence is mediated by fishes is unknown. By excluding fleshy macroalgae, cultivating palatable filamentous algae and engaging in frequent aggression to protect resources, territorial damselfish (f. Pomacentridae), such as Stegastes, mediate macro-benthic dynamics on coral reefs and may significantly influence microbial communities. To elucidate how Stegastes apicalis and Stegastes nigricans may alter benthic microbial assemblages and coral health, we determined the benthic community composition (epilithic algal matrix and prokaryotes) and coral disease prevalence inside and outside of damselfish territories in the Great Barrier Reef, Australia. 16S rDNA sequencing revealed distinct bacterial communities associated with turf algae and a two to three times greater relative abundance of phylotypes with high sequence similarity to potential coral pathogens inside Stegastes's territories. These potentially pathogenic phylotypes (totalling 30.04% of the community) were found to have high sequence similarity to those amplified from black band disease (BBD) and disease affected corals worldwide. Disease surveys further revealed a significantly higher occurrence of BBD inside S. nigricans's territories. These findings demonstrate the first link between fish behaviour, reservoirs of potential coral disease pathogens and the prevalence of coral disease. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  2. Unraveling the molecular signatures of oxidative phosphorylation to cope with the nutritionally changing metabolic capabilities of liver and muscle tissues in farmed fish.

    Science.gov (United States)

    Bermejo-Nogales, Azucena; Calduch-Giner, Josep Alvar; Pérez-Sánchez, Jaume

    2015-01-01

    Mitochondrial oxidative phosphorylation provides over 90% of the energy produced by aerobic organisms, therefore the regulation of mitochondrial activity is a major issue for coping with the changing environment and energy needs. In fish, there is a large body of evidence of adaptive changes in enzymatic activities of the OXPHOS pathway, but less is known at the transcriptional level and the first aim of the present study was to define the molecular identity of the actively transcribed subunits of the mitochondrial respiratory chain of a livestock animal, using gilthead sea bream as a model of farmed fish with a high added value for European aquaculture. Extensive BLAST searches in our transcriptomic database (www.nutrigroup-iats.org/seabreamdb) yielded 97 new sequences with a high coverage of catalytic, regulatory and assembly factors of Complex I to V. This was the basis for the development of a PCR array for the simultaneous profiling of 88 selected genes. This new genomic resource allowed the differential gene expression of liver and muscle tissues in a model of 10 fasting days. A consistent down-regulated response involving 72 genes was made by the liver, whereas an up-regulated response with 29 and 10 differentially expressed genes was found in white skeletal muscle and heart, respectively. This differential regulation was mostly mediated by nuclear-encoded genes (skeletal muscle) or both mitochondrial- and nuclear-encoded genes (liver, heart), which is indicative of a complex and differential regulation of mitochondrial and nuclear genomes, according to the changes in the lipogenic activity of liver and the oxidative capacity of glycolytic and highly oxidative muscle tissues. These insights contribute to the identification of the most responsive elements of OXPHOS in each tissue, which is of relevance for the appropriate gene targeting of nutritional and/or environmental metabolic disturbances in livestock animals.

  3. Farmed Atlantic salmon: potential invader in the Pacific Northwest?

    Science.gov (United States)

    Jonathan Thompson; Pete Bisson

    2008-01-01

    Commercial farming of Atlantic salmon in marine net-pens has become a booming industry. At present, approximately 130 salmon farms exist along the Pacific coast of North America. Most of these farms are in cold marine bays within British Columbia, where farmed salmon have become the province’s most valuable agricultural export. Each year, thousands of farmed Atlantic...

  4. Economic Indicators of the Farm Sector. Farm Sector Review, 1985.

    Science.gov (United States)

    Economic Research Service (USDA), Washington, DC.

    Farm production rose 6 percent in 1985 due to record high yields in corn, soybeans, cotton, and several other crops. While United States consumption increased slightly, exports of farm products fell 23 percent in value and 19 percent in volume. Net cash income increased 12 percent due to increased output, lower cash expenses, and unusually high…

  5. Establishing a benchmarking for fish farming - profitability, productivity and energy efficiency of German, Danish and Turkish rainbow trout grow-out systems

    DEFF Research Database (Denmark)

    Lasner, Tobias; Brinker, Alexander; Nielsen, Rasmus

    2017-01-01

    of freshwater trout farms in Germany, Denmark and Turkey, using a combination of existing data, group discussions and interviews with trout farmers, consultants and researchers. Nine 'typical' trout farming models are described, focusing on profitability, productivity and energy efficiency and allowing in......-depth comparative economic analyses of different production systems at farm level, across regions. Our results show that the majority of the farms investigated have been profitable. Turkish farms benefit from competitive advantages due to low wages, low capital investment and favourable climate conditions. Large....... Organic farms in both countries face challenges of high feed costs and comparatively low productivity with mixed success. Using edible protein energy return on investment (epEROI) as an indicator of ecological sustainability, all surveyed farms compared very favourably with the terrestrial systems...

  6. (Salmo trutta macrostigma) and Farmed Rainbow trout

    African Journals Online (AJOL)

    Userrr

    2013-04-06

    Apr 6, 2013 ... coronary artery diseases, neurodevelopment in infants, cancer, ... The difference in quality of meat between fish of wild and farmed origin has always been a matter of ..... Fish in cold water have high PUFA concentrations.

  7. Cowlitz Falls Fish Passage.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The upper Cowlitz was once home to native salmon and steelhead. But the combined impacts of overharvest, farming, logging and road building hammered fish runs. And in the 1960s, a pair of hydroelectric dams blocked the migration path of ocean-returning and ocean-going fish. The lower Cowlitz still supports hatchery runs of chinook, coho and steelhead. But some 200 river miles in the upper river basin--much of it prime spawning and rearing habitat--have been virtually cut off from the ocean for over 26 years. Now the idea is to trap-and-haul salmon and steelhead both ways and bypass previously impassable obstacles in the path of anadromous fish. The plan can be summarized, for the sake of explanation, in three steps: (1) trap and haul adult fish--collect ocean-returning adult fish at the lowermost Cowlitz dam, and truck them upstream; (2) reseed--release the ripe adults above the uppermost dam, and let them spawn naturally, at the same time, supplement these runs with hatchery born fry that are reared and imprinted in ponds and net pens in the watershed; (3) trap and haul smolts--collection the new generation of young fish as they arrive at the uppermost Cowlitz dam, truck them past the three dams, and release them to continue their downstream migration to the sea. The critical part of any fish-collection system is the method of fish attraction. Scientists have to find the best combination of attraction system and screens that will guide young fish to the right spot, away from the turbine intakes. In the spring of 1994 a test was made of a prototype system of baffles and slots on the upriver face of the Cowlitz Falls Dam. The prototype worked at 90% efficiency in early tests, and it worked without the kind of expensive screening devices that have been installed on other dams. Now that the success of the attraction system has been verified, Harza engineers and consultants will design and build the appropriate collection part of the system.

  8. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  9. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  10. OK-Net Arable online knowledge platform

    DEFF Research Database (Denmark)

    Rasmussen, Ilse Ankjær; Jensen, Allan Leck; Jørgensen, Margit Styrbæk

    2017-01-01

    The complexity of organic farming requires farmers to have a very high level of knowledge and skills, but exchange on organic farming techniques remains limited. In order to increase productivity and quality in organic arable cropping in Europe, the thematic network OK-Net Arable under Horizon 20...

  11. The Skin-Mucus Microbial Community of Farmed Atlantic Salmon (Salmo salar

    Directory of Open Access Journals (Sweden)

    Giusi Minniti

    2017-10-01

    Full Text Available The skin of the teleost is a flexible and scaled structure that protects the fish toward the external environment. The outermost surface of the skin is coated with mucus, which is believed to be colonized by a diverse bacterial community (commensal and/or opportunistic. Little is known about such communities and their role in fish welfare. In aquaculture, fish seem to be more susceptible to pathogens compared to wild fish. Indeed common fish farming practices may play important roles in promoting their vulnerability, possibly by causing changes to their microbiomes. In the present study, 16S rRNA gene amplicon sequencing was employed to analyze the composition of the farmed Salmo salar skin-mucus microbiome before and after netting and transfer. The composition of the bacterial community present in the rearing water was also investigated in order to evaluate its correlation with the community present on the fish skin. Our results reveal variability of the skin-mucus microbiome among the biological replicates before fish handling. On the contrary, after fish handling, the skin-mucus community exhibited structural similarity among the biological replicates and significant changes were observed in the bacterial composition compared to the fish analyzed prior to netting and transfer. Limited correlation was revealed between the skin-mucus microbiome and the bacterial community present in the rearing water. Finally, analysis of skin-mucus bacterial biomasses indicated low abundance for some samples, highlighting the need of caution when interpreting community data due to the possible contamination of water-residing bacteria.

  12. The Excavation of a Monastic Fishing Establishment at Oldstead Grange, North Yorkshire

    Directory of Open Access Journals (Sweden)

    Richard Kemp (with a pottery report by Wendy Sherlock

    1999-12-01

    Full Text Available Excavations directed by the writer in 1982-3 for the University of York Archaeological Society uncovered the foundations of a small structure on the shores of a fishpond that belonged to Byland Abbey in the 14th century. The site's location, combined with a number of associated lead net weights, suggest that it was connected with organised, large-scale, fish farming.

  13. EVALUACIÓN DEL KIT FISH FARMING FF1A ® PARA ANÁLISIS DE CALIDAD DE AGUAS EN ACUICULTURA

    Directory of Open Access Journals (Sweden)

    González J. F.

    2006-11-01

    Full Text Available Se evaluó a través de métodos analíticos alternos y mediciones de varios observadores la confiabilidad en la cuantificación de pH, nitrito (NO2, amoniaco (NH3 y oxígeno disuelto (O2 en aguas utilizando el kit Fish Farming FF1A ® (Hach. El análisis de NH3 tuvo el mayor coeficiente de variación (CV = 15,2 cuando diferentes observadores (n=11 analizaron una muestra problema. Dos muestras (0,5 y 3,0 ppm N-NO2 fueron usadas para medir NO2 comparando el método de diazotización y las lecturas obtenidas con el kit por diferentes observadores (n=10. Los resultados para la primera muestra fueron muy similares (diazotización = 0,54 ppm y Hach = 0,41 ppm N-NO2, CV = 10,5. En la segunda, se presentó una mayor diferencia (diazotización = 4,10 ppm y Hach = 2,97 ppm N-NO2, CV = 14,9. El promedio del pH (n=17 con el kit fue 7,29 ± 0,2 (CV = 2,77; mientras que con el potenciómetro fue de 7,06. La medición de O2 usando el kit arrojó un resultado promedio de 6,1 ± 0,57 ppm (CV = 9,3 mientras que con el oxímetro fue de 4,67 ± 0,15 ppm (CV = 3,2 para 10 mediciones seguidas, hechas sobre un mismo punto en un tanque de peces. El kit de Hach mostró una buena sensibilidad para la medición del pH. El NH3 indicó la mayor dispersión de resultados y los valores de O2 con el kit estuvieron siempre por encima del valor registrado por el oxímetro. Estos resultados sugieren que para algunas variables (amoniaco, nitrito, el kit tiene imprecisiones determinando los valores reales en las aguas analizadas. Para el nitrito, ésto sería de riesgo para especies muy susceptibles al mismo (ej. salmónidos, peces gato mientras que para el amoniaco, imprecisiones en la cuantificación serían de alto riesgo para todas las especies dada la alta susceptibilidad a este metabolito.

  14. EVALUACIÓn DEL KIT FISH FARMING FF1A ® PARA ANÁLI SIS DE CALIDAD DE AGUAS EN ACUICULTURA

    Directory of Open Access Journals (Sweden)

    HE. Higuera

    2006-01-01

    Full Text Available Se evaluó a través de métodos analíticos alternos y mediciones de varios observadores la contabilidad en la cuantificación de pH, nitrito (NO2, amoniaco (NH3 y oxígeno disuelto (O2 en aguas utilizando el kit Fish Farming FF1A ® (Hach. El análisis de NH3 tuvo el mayor coeficiente de variación (CV = 15,2 cuando diferentes observadores (n=11 analizaron una muestra problema. Dos muestras (0,5 y 3,0 ppm N-NO2 fueron usadas para medir NO2 comparando el método de diazotización y las lecturas obtenidas con el kit por diferentes observadores (n=10. Los resultados para la primera muestra fueron muy similares (diazotización = 0,54 ppm y Hach = 0,41 ppm N-NO2,CV = 10,5. En la segunda, se presentó una mayor diferencia (diazotización = 4,10 ppm y Hach = 2,97 ppm N-NO2, CV = 14,9. El promedio del pH (n=17 con el kit fue 7,29 ± 0,2 (CV = 2,77; mientras que con el potenciómetro fue de 7,06. La medición de O2 usando el kit arrojó un resultado promedio de 6,1 ± 0,57 ppm (CV = 9,3 mientras que con el oxímetro fue de 4,67 ± 0,15 ppm (CV = 3,2 para 10 mediciones seguidas, hechas sobre un mismo punto en un tanque de peces. El kit de Hach mostró una buena sensibilidad para la medición del pH. El NH3 indicó la mayor dispersión de resultados y los valores de O2 con el kit estuvieron siempre por encima del valor registrado por el oxímetro. Estos resultados sugieren que para algunas variables (amoniaco, nitrito, el kit tiene imprecisiones determinando los valores reales en las aguas analizadas. Para el nitrito, ésto sería de riesgo para especies muy susceptibles al mismo (ej. salmónidos, peces gato mientras que para el amoniaco, imprecisiones en la cuantificación serían de alto riesgo para todas las especies dada la alta susceptibilidad a este metabolito.

  15. Actions for the development of local productive arrangement of fish farming in the municipality of Sobradinho/BA | Ações para o desenvolvimento de arranjos produtivos locais de piscicultura no município de Sobradinho / BA

    Directory of Open Access Journals (Sweden)

    Eberson Pessoa Ribeiro

    2016-06-01

    Full Text Available Local productive arrangements (LPAs are important options for the implementation of job-creating public policies and income in a sustainable way. In Brazil, such policies to encourage organizations, although recent, has become consistent and the results of its implementation can already be perceived. This work consisted in analyzing the performance of the Development Company of the São Francisco and Parnaíba (Codevasf in the local productive arrangement of fish farming in the municipality of Sobradinho/BA. Through documentary research in the database of the 6th Regional Superintendency and interviews with engineers Unit of the Regional Revitalization Management - Territorial Development Unit of the institution, arrangement of characteristics and the benefits for the participants and the local population were raised. As results, it was found that after the company's participation in LPAs was a considerable increase in production, marketing and consumption of fish as well as the creation of new job opportunities in the region.

  16. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  17. Petri Nets

    Indian Academy of Sciences (India)

    Associate Professor of. Computer Science and. Automation at the Indian. Institute of Science,. Bangalore. His research interests are broadly in the areas of stochastic modeling and scheduling methodologies for future factories; and object oriented modeling. GENERAL I ARTICLE. Petri Nets. 1. Overview and Foundations.

  18. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Petri Nets - Overview and Foundations. Y Narahari. General Article Volume 4 Issue 8 August 1999 pp ... Author Affiliations. Y Narahari1. Department ot Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  19. Response of lake water quality to wastewater inputs from land-based fish farm located on Yuvarlakçay Creek in Köyceğiz-Dalyan Specially Protected Area, Turkey.

    Science.gov (United States)

    Taşeli, B K

    2009-10-01

    Köyceğiz Lake is located in the south-western part of Turkey. The area between the Köyceğiz Lake and the Mediterranean Sea is covered with four small lakes and several canals. The surroundings of the lake, canals and forests have a great potential as a reproduction areas for Mediterranean Sea turtles (Caretta caretta) and sheltering place for various animals. In the vicinity of this system there are agricultural areas and small settlements. In this region the most important economic activities are tourism and fisheries. However, the lake is currently threatened by pollution because of (1) non-point source pollution (agriculture); (2) point sources (land-based fish farms); (3) inefficient sewerage systems; (4) uncontrolled soil erosion in its drainage basin; (5) inappropriate flood control measures; and (6) channel traffic. This study evaluates the influence of its influent creeks namely Namnam and Yuvarlakçay Creek on the water quality of Köyceğiz Lake, mainly because the creeks are believed to be responsible for the major pollutant load reaching the lake. Accordingly, this study demonstrates (1) change in the water quality of Köyceğiz Lake from 2006 to 2007; (2) the water quality classification of the major influent creeks feeding Köyceğiz Lake; and (3) how land-based fish farm influences Yuvarlakçay Creek water quality in a Köyceğiz-Dalyan Specially Protected Area.

  20. A game theory based framework for assessing incentives for local area collaboration with an application to Scottish salmon farming.

    Science.gov (United States)

    Murray, Alexander G

    2014-08-01

    Movements of water that transport pathogens mean that in net-pen aquaculture diseases are often most effectively managed collaboratively among neighbours. Such area management is widely and explicitly applied for pathogen management in marine salmon farms. Effective area management requires the active support of farm managers and a simple game-theory based framework was developed to identify the conditions required under which collaboration is perceived to be in their own best interest. The model applied is based on area management as practiced for Scottish salmon farms, but its simplicity allows it to be generalised to other area-managed net-pen aquaculture systems. In this model managers choose between purchasing tested pathogen-free fish or cheaper, untested fish that might carry pathogens. Perceived pay-off depends on degree of confidence that neighbours will not buy untested fish, risking input of pathogens that spread between farms. For a given level of risk, confidence in neighbours is most important in control of moderate-impact moderate-probability diseases. Common low-impact diseases require high confidence since there is a high probability a neighbour will import, while testing for rare high-impact diseases may be cost-effective regardless of neighbours actions. In some cases testing may be beneficial at an area level, even if all individual farms are better off not testing. Higher confidence is required for areas with many farms and so focusing management on smaller, epidemiologically imperfect, areas may be more effective. The confidence required for collaboration can be enhanced by the development of formal agreements and the involvement of outside disinterested parties such as trade bodies or government. Copyright © 2014. Published by Elsevier B.V.

  1. 1993 farming and grazing program plans for Monte Vista NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Plans for farming and grazing at Monte Vista National Wildlife Refuge for 1993. This program will use rotations of small grain, field peas, and legumes as a farming...

  2. Fish species, Fish biomass, Fishery survey, invertebrate species, and other variables collected from midwater net tows, and bottom trawl observations using net, trawl, and other instruments from the Arctic Ocean, and Beaufort Sea from August 6, 2008 to August 21, 2008 (NODC Accession 0112823)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska Fisheries Science Center's Status of Stocks and Multispecies Assessment (SSMA) Programs Fishery Interaction Team (FIT) conducted a fish survey in the...

  3. Characterisation of aroma-active and off-odour compounds in German rainbow trout (Oncorhynchus mykiss). Part II: Case of fish meat and skin from earthen-ponds farming.

    Science.gov (United States)

    Mahmoud, Mohamed Ahmed Abbas; Buettner, Andrea

    2017-10-01

    Odorous molecules in earthen-ponds rainbow trout aquaculture farming in Germany were investigated with a special focus on musty-earthy off-odorants. To this aim, fish meat and skin were extracted using solvent-assisted flavour evaporation (SAFE) and were mildly concentrated; extracts were subsequently analysed by means of one- and two-dimensional high-resolution gas chromatography coupled with mass spectrometry and olfactometry (GC-MS/O and 2D-HRGC-MS/O). Aroma extract dilution analysis (AEDA) of the solvent extracts revealed the presence of 76 odorants of which 75 were successfully identified. Thereby, rotundone (black pepper) is described for the first time as an odour-active substance in fish. Moreover, a series of compounds is described for the first time in German aquaculture rainbow trout fish, including, amongst others, (E,Z,Z)-2,4,7-tridecatrienal, (E)-4,5-epoxy-(E)-2-decenal, 4-ethyloctanoic acid, 3-methylindole (skatole), d-limonene, and indole. The analytical findings were further compared to sensory evaluation of the samples, and previously obtained data on the respective aquacultural water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Efficacy of the treatments used for the control of Caligus rogercresseyi infecting Atlantic salmon, Salmo salar L., in a new fish-farming location in Region XI, Chile.

    Science.gov (United States)

    Bravo, S; Nuñez, M; Silva, M T

    2013-03-01

    Caligus rogercresseyi is the most important parasite affecting Atlantic salmon and rainbow trout farming in sea water in Chile. After the outbreaks of the infectious salmon anaemia recorded in Region X from 2007, the salmon industry has expanded southwards to Region XI, where 60% of Atlantic salmon in Chile is now produced. In parallel with the relocation of salmon production, sea lice infestation has also spread to Region XI, and today C. rogercresseyi is the most serious threat to the salmon-farming industry in this region. The results obtained through a year of monitoring between September 2007 and August 2008 on a farm located in the 'Las Guaitecas Archipelago' in Region XI (44°S; 74°W) showed that treatments with emamectin benzoate and deltamethrin did not give the expected control of Caligus. Failures of the treatments were associated with the loss of sensitivity recorded for C. rogercresseyi to emamectin benzoate in Region X. In addition, a major influence was the lack of delousing coordination measures with the neighbouring farms sharing the same area in that period. © 2013 Blackwell Publishing Ltd.

  5. Animal welfare in brown trout farming: hematological results

    Directory of Open Access Journals (Sweden)

    G. Forneris

    2010-01-01

    Full Text Available The effect of stress resulting from fish farming has received considerable attention in this last period and fish welfare in aquaculture is a relevant topic, very important for the future of aquaculture (Watson et al., 2004; Klinger et al., 1996; Peres et al., 2004; Ron et al., 1995;Wagner et al., 1995;Watson et al., 1998. Brown trout farming is less developed then rainbow trout farming, but this kind of fish farming is increasing, mainly for fish conservation and restocking aquaculture.

  6. Fish parasites, fish food, and the marine environment | Nnadi ...

    African Journals Online (AJOL)

    The most notorious among these are the lampreys, some of the acanthocephalans, and the copepods. The alarm is raised in the paper that this combined scourge of fish farming, fish production and fish availability must be brought under control as part of the general food security strategy. The paper posits that the adoption ...

  7. Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus reared in hapas nets and earth nurseries in the northern region of Parana State, Brazil

    Directory of Open Access Journals (Sweden)

    Salvador Rogério

    2005-01-01

    Full Text Available The objective of this study was to isolate and characterize Streptococcus spp. in Nile tilapias (Oreochromis niloticus reared in net-pens and earth nurseries. Eight intensive tilapia-rearing farms were investigated in north Paraná, Brazil from April 1st 2001 to April 30th 2002. The fish were reared in a system of hapas nets on four farms and in earth nurseries on other four farms. A total of 370 samples were analyzed of material collected from 120 fish (brain, liver, kidney, skin scrapes, ascites liquid and eye that were sown on BHI agar (Brain Heart Infusion supplemented with 1% yeast extract and sheep blood. Streptococcus spp. was isolated in 36 of the samples (18 brain, eight liver, eight kidney and two ascites liquid from 25 fish. Streptococci were isolated in both systems, almost in the same proportion. First the streptococci were characterized by the catalase and esculin test, growth in methylene blue and sodium chloride at 6.5%. They were classified in groups by the Slidex Strepto-Kit (BioMerieux, France. The phenotypic characteristics were determined by the Api 20 Strep microtest system (BioMerieux, France. The 36 Streptococcus spp. samples did not present hemolysis and were classified as Lancefield group B. Further 16 samples were identified as Streptococcus agalactiae and 20 were not identified by the Api 20 Strep, but presented the same biochemical profile described for the reference strain of Streptococcus difficile (ND-2-22.

  8. Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda).

    Science.gov (United States)

    Ogawa, K

    2015-01-01

    Mariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.

  9. Farm Women Blend Farm and Off-Farm Work.

    Science.gov (United States)

    Perry, Janet E.; Ahearn, Mary C.

    1994-01-01

    A study of farm operator households indicates that although women participate in farm management, men still manage the majority of farms; women farm operators spend fewer hours in farm and off-farm work than men; and when women work in off-farm employment, the household has a higher average income. (LP)

  10. Piggerywaste management and profitability of pig farming in Imo ...

    African Journals Online (AJOL)

    Data were analyzed using descriptive statistics, operating net returns and benefit cost ratio. Net profits of the different categories of pig farms based on their waste management systems were compared using ANOVA statistics. The result shows that 75% of the pig farms managed their waste by open dumping, produced an ...

  11. Economic Analysis of Eucheumoid Algae Farming in Kenya ...

    African Journals Online (AJOL)

    This was done to determine their net yield and economic viability and included sensitivity analysis to determine the effects of decreased farm gate prices and increased operating costs on the return of investment (ROI) and payment period in eucheumoid farming. The average net yield varied from 880 to 1209 kg dry wt for E.

  12. African Journals Online: Fish & Fisheries

    African Journals Online (AJOL)

    Today the membership of the society has expanded cutting across all the related disciplines including fisheries scientists, fishing companies and professional industrial fishing/fish farming enthusiasts and entrepreneurs. The Nigerian Journal of Fisheries is aimed at encouraging needed research into multivariate fisheries ...

  13. Gill net and trammel net selectivity in the northern Aegean Sea, Turkey

    Directory of Open Access Journals (Sweden)

    F. Saadet Karakulak

    2008-09-01

    Full Text Available Fishing trials were carried out with gill nets and trammel nets in the northern Aegean Sea from March 2004 to February 2005. Four different mesh sizes for the gill nets and the inner panel of trammel nets (16, 18, 20 and 22 mm bar length were used. Selectivity parameters for the five most economically important species, bogue (Boops boops, annular sea bream (Diplodus annularis, striped red mullet (Mullus surmuletus, axillary sea bream (Pagellus acarne and blotched picarel (Spicara maena, caught by the two gears were estimated. The SELECT method was used to estimate the selectivity parameters of a variety of models. Catch composition and catch proportion of several species were different in gill and trammel nets. The length frequency distributions of the species caught by the two gears were significantly different. The bi-modal model selectivity curve gave the best fit for gill net and trammel net data, and there was little difference between the modal lengths of these nets. However, a clear difference was found in catching efficiency. The highest catch rates were obtained with the trammel net. Given that many discard species and small fish are caught by gill nets and trammel nets with a mesh size of 16 mm, it is clear that these nets are not appropriate for fisheries. Consequently, the best mesh size for multispecies fisheries is 18 mm. This mesh size will considerably reduce the numbers of small sized individuals and discard species in the catch.

  14. Environmental impact of sea bass cage farming in the north Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Domenico Lanari

    2010-01-01

    Full Text Available The main objective of the research was to reduce the organic and nutrient load under the net pen fish farms. An exper- iment was conducted to study the effects of artificial barriers fixed under a set of sea cages in order to reduce the envi- ronmental impact. The artificial barriers were made of four submerged galvanized steel pipes coated with plastic and placed on the sea floor (10 m depth in the Trieste gulf. The experimental design was as follows: control (C, cages with barriers (B, cages without barriers (WB. Measurements were taken on the surface as well as at 4 and 8m of depth. The trial lasted from the end of June 2000 to December 2001. Water quality parameters were not significantly influenced by the fish cages. Surface samples were characterised by lower levels of salinity and higher levels of oxygen and nitrate compared to those taken at 4 and 8 m. The artificial barriers favoured the establishment of a rich epiphytic fauna that took advantage of the presence of organic matter derived from fish cages. The two species Nucula nucleusand Neanthes caudataand the total bacterial counts were identified as potential indicators of pollution under the fish cage farms.

  15. StreamNet; 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Columbia River Inter-Tribal Fish Commission

    2000-01-01

    This report was funded by the Bonneville Power Administration (BPA), US Department of Energy, as part of BPA's program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The views of this report are the author's and do not necessarily represent the views of BPA. This annual report covers progress made by: Columbia River Inter-Tribal Fish Commission Idaho; Department of Fish and Game; Montana Department of Fish, Wildlife and Parks; Oregon Department of Fish and Wildlife; Pacific States Marine Fisheries Commission; Shoshone-Bannock Tribes; US Fish and Wildlife Service; Washington Department of Fish and Wildlife; and FY1999 StreamNet Quickplan.

  16. DIEL AND VERTICAL DYNAMIC OF LIMNOLOGICAL CHARACTERISTICS IN FISH REARING NET-CAGES ENVIROMENT DINÂMICA NICTIMERAL E VERTICAL DAS CARACTERÍSTICAS LIMNOLÓGICAS EM AMBIENTE DE CRIAÇÃO DE PEIXES EM TANQUES-REDE

    Directory of Open Access Journals (Sweden)

    Odair Diemer

    2010-04-01

    Full Text Available

    This study aimed to verify the diel and vertical dynamic characteristics in limnological environment for rearing native fish in net-cage at the reservoir of Itaipu Binacional. The parameters evaluated were water temperature, dissolved oxygen, electrical conductivity, pH, phosphorus, nitrite and ammonia. It was found that there was diel variation for all parameters, except for ammonia and phosphorus. But the variables are in the recommended limits for aquaculture, with the exception of dissolved oxygen that showed critical rates at night. For the vertical distribution concentrations of physical and chemical parameters of water did not exceed the limit established by CONAMA Resolution 357/05 for fish rearing, however, there was vertical variation for nitrite and phosphorus.

    KEY WORDS: Aquaculture, intensive culture, limnology, water quality.

    O presente trabalho teve como objetivo verificar a dinâmica nictimeral e vertical das características limnológicas em ambiente de criação de peixes nativos em tanques-rede no reservatório da Itaipu Binacional. Os parâmetros avaliados foram temperatura da água, oxigênio dissolvido, condutividade elétrica, pH, fósforo total, nitrito e amônia. Verificou-se que ocorreu variação nictimeral para todos os parâmetros, exceto para amônia e fósforo total. Entretanto, as variáveis estão dentro dos limites recomendados para a aquicultura, com exceção do oxigênio dissolvido, que apresentou valores críticos à noite. Para a distribuição vertical, as concentrações dos parâmetros físicos e químicos da água não ultrapassaram o limite estabelecido pela resolução do CONAMA 357/05 para criação de peixes. No entanto, houve variação vertical para nitrito e fósforo.

    PALAVRAS-CHAVES: Aquicultura, cultivo intensivo, limnologia, qualidade de água.

  17. Operational welfare indicators (OWI) in rainbow trout farming

    DEFF Research Database (Denmark)

    Buchmann, Kurt

    2007-01-01

    A number of welfare parameters are defined in order to create tools for the future management of welfare in farmed fish......A number of welfare parameters are defined in order to create tools for the future management of welfare in farmed fish...

  18. Antioxidant property of wild and farmed sea bream ( Sparus aurata ...

    African Journals Online (AJOL)

    1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and hydroxyl radicalscavenging activity (RSA) as well as the reducing power activity of different extracts increased linearly with increasing concentration. DPPH scavenging activity was more effective with farmed fish extracts. Extracts of oven cooked wild and grilled farmed fish ...

  19. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2001-01-01

    A collection of 313 motile aeromonads isolated at Danish rainbow trout farms was analyzed to identify some of the genes involved in high levels of antimicrobial resistance found in a previous field trial (A. S. Schmidt, M. S. Bruun, I. Dalsgaard, K. Pedersen, and J. L. Larsen, Appl. Environ....... Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among...... the isolates containing integrons, four different combinations of integrated resistance gene cassettes occurred, in all cases including a dihydrofolate reductase gene and a downstream aminoglycoside resistance insert (87 isolates) and occasionally an additional chlor-amphenicol resistance gene cassette (31...

  20. 75 FR 61248 - Proposed Information Collection (Pension Claim Questionnaire for Farm Income) Activity: Comment...

    Science.gov (United States)

    2010-10-04

    ... solicits comments on information needed to determine net income derived from farming. DATES: Written... claimant's countable annual income and available assets due to farm operations. Farm income is not necessarily received on a weekly or monthly basis, and farm operating expenses must be considered in...

  1. 78 FR 34174 - Proposed Information Collection (Pension Claim Questionnaire for Farm Income) Activity: Comment...

    Science.gov (United States)

    2013-06-06

    ... solicits comments on information needed to determine net income derived from farming. DATES: Written... claimant's countable annual ] income and available assets due to farm operations. Farm income is not necessarily received on a weekly or monthly basis, and farm operating expenses must be considered in...

  2. Farm Tourism

    DEFF Research Database (Denmark)

    Blichfeldt, Bodil Stilling; Nielsen, Niels Christian; Nissen, Kathrine Aae

    2011-01-01

    This paper draws on a study of one specific type of small tourism enterprises (i.e. farm tourism enterprises) and argues that these enterprises differ from other enterprises in relation to a series of issues other than merely size. The analysis shows that enterprises such as these are characterized......, our study suggests that it is problematic to threat farm tourism enterprises as if they have much in common with both larger corporations and other types of SMTEs. Farm tourism enterprises seem to differ significantly from other enterprises as the hosts are not in the tourism business because...

  3. Survey of rainbow trout mortality in cage culture farms in Hasanloo Dam, west Azerbaijan province

    Directory of Open Access Journals (Sweden)

    amin Khodadadi

    2014-08-01

    Full Text Available In late June 2013, because of sudden and unjustified increase in mortality of apparent healthy fish in Hasanloo dam cage culture, random sampling was convicted from a live dying and dead fishes. Forty fishes (20 alive and 20 dead fishes from two cage with the weight of 200-300 gr were sampled. Samples were sent to private factor laboratory ice pieces for evolution. Some physicochemical parameters of Hasanloo dam water including nitrite, nitrate, ammonium, soluble solid materials, temperature, dissolved oxygen and pH was measured.  To investing the probability of bacterial, fungal and parasitic discover outbreaks sample were taken from the kidney, gills and skin of fish. The result of different investing revealed the presence of algal bloom, oxygen shortage, executive problems and fishing net fountain obstruction due to accumulation of planktons and suspended material. Because of increase in light intensity, nutritive substances level, warming of water temperature and static suability of water hydrological status, algal blooming had occurred in Hasanloo dam that not only destroyed the gills of fish but also created competition for soluble oxygen at night with some phytoplankton species causing hypoxia and death of salmon in the breeding farm. The result of general bacterial cutler was negative and mild secondary infection with S aprolegnia species was detected in PGYEA culture. The result of liver histopathology indicated the presence of hepatic ceroidosis because of non-standard diets with high levels of carbohydrates. Gill blade inflammation and hyperplasia was the observed. Due to high amounts of ionized ammonia among culture nets resolving from summer mortality syndrome.

  4. Broad-scale impacts of salmon farms on temperate macroalgal assemblages on rocky reefs.

    Science.gov (United States)

    Oh, E S; Edgar, G J; Kirkpatrick, J B; Stuart-Smith, R D; Barrett, N S

    2015-09-15

    Intensive fish culture in open sea pens delivers large amounts of nutrients to coastal environments. Relative to particulate waste impacts, the ecological impacts of dissolved wastes are poorly known despite their potential to substantially affect nutrient-assimilating components of surrounding ecosystems. Broad-scale enrichment effects of salmonid farms on Tasmanian reef communities were assessed by comparing macroalgal cover at four fixed distances from active fish farm leases across 44 sites. Macroalgal assemblages differed significantly between sites immediately adjacent (100m) to fish farms and reference sites at 5km distance, while sites at 400m and 1km exhibited intermediate characteristics. Epiphyte cover varied consistently with fish farm impacts in both sheltered and exposed locations. The green algae Chaetomorpha spp. predominated near fish farms at swell-exposed sites, whereas filamentous green algae showed elevated densities near sheltered farms. Cover of canopy-forming perennial algae appeared unaffected by fish farm impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Consumers’ attitude towards fish meat

    Directory of Open Access Journals (Sweden)

    Francesca Conte

    2014-09-01

    Full Text Available The overall aim of this paper is to show the factors that may affect consumers’ attitude towards farmed fish products. Consumers ask new products on the basis of different quality attributes: stability, safety, composition, better health effects, environment protection, etc. Different and controversial opinions on farmed and wild fish are also explored by literature review. The authors pay attention also to fish welfare as an emerging issue and effective information about fish products as a factor exerting a positive influence on consumers’ decision of purchase. Some relevant legislative notes on the paper’s topics are also cited. The qualitative aspects of aquaculture fish and the consumers’ demand and choice need further studies, according to some factors, such as the changing consumers’ attitudes towards fish products, the different fish quality perception and the development in the aquaculture systems.

  6. Farm Animals

    Science.gov (United States)

    ... Press Kit Connect With Us New & Noteworthy Farm Animals Recommend on Facebook Tweet Share Compartir Overview Diseases ... Tips for staying healthy at petting zoos and animal exhibits Do not eat food or drink beverages ...

  7. An approach to salmon farming in Norway : a future for land based salmon farming?

    OpenAIRE

    Tvete, Anders

    2016-01-01

    The aim of this thesis is to give an overview over the salmon farming industry in Norway. It presents some theory around production- and investment costs associated with land basedand sea based fish farming, as well as challenges around environmental issues, technology, fish feed etc. Several production concepts such as open cages in the sea, cages offshore, closed operations in the sea, both exposed and protected and land based production sites are available today, and the cha...

  8. Monitoring of trace metals, biochemical composition and growth of Axillary seabream (Pagellus acarne Risso, 1827 in offshore Copper alloy net cage

    Directory of Open Access Journals (Sweden)

    M. YIGIT

    2016-02-01

    Full Text Available The study was conducted to assess trace metal contents, biochemical composition and growth performance of axillary seabream (Pagellus acarne Risso, 1827 cultured in a copper alloy mesh cage. A total of 400 axillary seabream (initial mean weight: 176.0±14.0 g, a new candidate species for the Mediterranean aquaculture, were stocked into a high-density polyethylene frame gravity cage and fed a commercial seabream diet for a period of 6 months. At the end of the feeding trial, fish reached a final weight of 264.8±16.8 g with a weight increase of 88.8 g and a feed conversion rate of 2.51. Overall, relative growth rate, specific growth rate and feed conversion ratio were satisfactory and comparable to the pelagic fishes such as gilthead seabream or European seabass, which are presently the main fish species for the Mediterranean aquaculture industry. Trace elements in fish grown in copper alloy net cages over a 6-month period showed satisfactory results, as the metal concentrations in fish tissues such as liver, skin, muscle and gills were below the reported upper limits for human consumption, indicating that copper alloy net is an acceptable and safe material for finfish cage aquaculture. Furthermore, from the growth performance data obtained in the present study, it can be concluded that axillary seabream showed potential for cage farming, and thus is a promising new candidate for the Mediterranean aquaculture industry.

  9. Parasitism of Argulus japonicus in cultured and wild fish of Guangdong, China with new record of three hosts.

    Science.gov (United States)

    Alsarakibi, Muhamd; Wadeh, Hicham; Li, Guoqing

    2014-02-01

    This study aimed to demonstrate the ability of Argulus japonicus to infect a wide range of freshwater fishes, as well as to understand the effects of fish origin and host body size on the incidence of A. japonicus. Samples of cultured and wild fish were collected randomly from July 2010 to March 2013, using angling, long-lining, gill-netting, and trapping from rivers and fish farms in Guangdong province, South China. Eight fish species were found to be heavily infected including the common carp, the goldfish, the black carp, the silver carp, the brown trout, the rainbow trout, the mandarin fish, and the perch. Furthermore, the black carp, the brown trout, and the mandarin fish were recorded as new hosts for the first time. During the present study, a total of 2,271 fishes were examined, out of which 712 fishes were found to be infected by a total of 1,443 A. japonicus. Abundance and intensity of A. japonicus infection were significantly influenced by origin of fishes (cultured and wild) and total length (class I, 350 mm) of fish species, whereas varied impacts on prevalence of infection were observed. The correlation between total length of fishes and prevalence of A. japonicus infection was variable, where no significant correlation was observed in the black carp, the silver carp, the mandarin fish, and the perch. In spite of the weak negative correlation between body size of the silver carp and prevalence of infection, A. japonicus was the most abundant and intensive in the silver carp. Thus, aquaculturists should pay particular attention to the control of these fish lice due to its host biodiversity.

  10. Current bacterial diseases of fresh water fishes

    OpenAIRE

    Jeremić Svetlana; Radosavljević Vladimir; Jakić-Dimić Dobrila

    2005-01-01

    From the beginning of fish cultivation, diseases have appeared as a serious problem in this branch of agriculture. In recent years, by the intensifying of production, fish diseases have become even more significant and complex field. Bacterial diseases are constant threat for fish farming, and because of rapid course and severity of clinical manifestations the represent significant part of fish pathology, and also have great economical importance. Harmful effects of bacterial diseases on fish...

  11. Comparative study of the nutritional composition and toxic elements of farmed and wild Chanodichthys mongolicus

    Science.gov (United States)

    Jiang, Haifeng; Cheng, Xiaofei; Geng, Longwu; Tang, Shizhan; Tong, Guangxiang; Xu, Wei

    2017-07-01

    Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements. Proximate composition, amino acid and fatty acid profiles, and toxic elements contents of farmed and wild Chanodichthys mongolicus were established and compared. Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed ( Pamino acids (TAA), total essential amino acids (TEAA), total non-essential amino acids (TNEAA) and total delicious amino acids (TDAA) in farmed fish were all significantly higher than those in the wild equivalent ( Pacid profiles in both farmed and wild C. mongolicus were dominated by monounsaturated fatty acid (MUFA), with farmed fish contained much more MUFA content compared to wild counterpart ( Pfish exhibited significantly higher levels of total polyunsaturated fatty acid (PUFA) including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than farmed fish ( Pacid (C18:2n6) were the predominant PUFA in wild and farmed C. mongolicus, respectively. Moreover, farmed fish displayed an overall lower toxic element levels (As, Cd, Pb and Hg) in comparison with wild fish, and both were far lower than the established limit standard. In conclusion, our results suggest that the nutritional quality of farmed C. mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition, and therefore further studies should focus on the improving C. mongolicus diet in order to enhance the overall nutritional composition.

  12. Relação parasito-hospedeiro em peixes de pisciculturas da região de Assis, Estado de São Paulo, Brasil. 1. Oreochromis niloticus (Linnaeus, 1757 - DOI: 10.4025/actascibiolsci.v29i2.594 Host-parasite relationship in fish from fish farms in the Assis region, São Paulo State, Brazil. 1. Oreochromis niloticus (Linnaeus, 1757

    Directory of Open Access Journals (Sweden)

    Maria José Tavares Ranzani-Paiva

    2007-12-01

    Full Text Available Um total de 90 espécimes de Oreochromis niloticus foi coletado bimestralmente entre os meses de fevereiro a dezembro de 2004, em três pisciculturas do Estado de São Paulo. Do total, 82,2% estavam parasitados por pelo menos uma espécie de parasito. Os parâmetros físicos e químicos da água foram utilizados para caracterizar a qualidade da água em cada propriedade. Sete espécies de ectoparasitos foram registradas. Foi possível observar que as pisciculturas apresentam a mesma parasitofauna, porém cada propriedade apresenta uma estrutura da comunidade peculiar. Cichlidogyrus sclerosus e Cichlidogyrus sp. 1 apresentaram correlação negativa significativa da abundância com o comprimento padrão do hospedeiro somente em Palmital. A espécie Cichlidogyrus sp. 2 e o copépode Lamproglena sp. apresentaram correlação positiva significativa da abundância com o comprimento padrão nas pisciculturas de Tarumã e Cândido Mota, respectivamente. Em relação ao fator de condição relativo, somente a espécie Cichlidogyrus sp. 1 apresentou correlação significativa negativa com a abundância de parasitismo. Lamproglena sp. apresentou correlação positiva significativa com a relação hepatossomática (RHS das tilápias em Palmital, e o ergasilídeo apresentou correlação significativa negativa da abundância de parasitismo e a relação esplenossomática (RES dos hospedeiros em Cândido Mota.A total of ninety specimens of Oreochromis niloticus were collected every other month between February and December of 2004 at three fish farms in São Paulo State. 82.2% were parasitized by at least one species of parasite. Physical and chemical water parameters were used to characterize water quality in each fish farm. Seven species of ectoparasites were registered. It was possible to observe that all fish farms presented the same parasite fauna; however, each farm featured its own peculiar community structure. Cichlidogyrus sclerosus and Cichlidogyrus

  13. Heterosigma bloom and associated fish kill

    Science.gov (United States)

    Hershberger, P.K.; Rensel, J.E.; Postel, J.R.; Taub, F.B.

    1997-01-01

    A bloom of the harmful marine phytoplankton, Heterosigma carterae occurred in upper Case Inlet, south Puget Sound, Washington in late September, 1994, correlating with the presence of at least 35 dead salmon. This marks the first time that this alga has been closely correlated with a wild fish kill; in the past it was thought to be associated with kills of penned fish at fish farms only. We were informed of the presence of a possible harmful algal bloom and dead salinois Ilear the town of Allyn on 27 September and a team was formed to investigate. We arrived at the Allyn waterfront at 17:30 hours the same day. Prior to our arrival, state agency personnel walked approximatcly two miles of shoreline from the powerlines north of the dock, to the mouth of Sherwood Creek and conducted the only official count of dead fish present along the shore consisting of 12 coho salmon (Oncorhynchus kisutch), 11 chum salmon (Oncorhynchus keta), 12 chinook salmon (Oncorhynchus tschawytscha), one flat fish, and one sculpin on the morning of 9/27. Since previous harmful blooms of Heterosigma have resultedin the majority of net penreared salmon sinking to the bottom of pens, and only approximately two miles of shoreline were sampled, it is suspected that many more exposed fish may have succumbed than were counted. Witnesses who explored the east side of the bay reported seeing many dead salmon there as well, but no counts were made. State agency personnel who observed the fish kill reported seeing “dying fish coming to the beach, gulping at the surface, trying to get out of the water” Scavengers were seen consuming the salmon carcasses; these included two harbor seals, a house cat, and Hymenopteran insects. None suffered any noticeable acute ill effects. Although precise cause of death has not been ascertained, visual inspection of the reproductive organs from a deceased male chum salmon found on the shore at Allyn confirmed that the fish was not yet reproductively mature and

  14. Rhabdoviruss-Induced Fish-Specific Microribonucleic Acids in Rainbow Trout (Oncorhynchus Mykiss)

    DEFF Research Database (Denmark)

    Bela-Ong, Dennis; Schyth, Brian Dall; Lorenzen, Niels

    The fish rhabdovirus, Viral hemorrhagic septicemia virus (VHSV), causes significant mortality in farmed fish. The potential threat from wildlife marine reservoir of VHSV to sea-farmed rainbow trout (Oncorhynchus mykiss) demands disease protection measures. Identification of biomarkers during infe...

  15. Risk assessment of fish health and fish welfare in freshwater production systems

    OpenAIRE

    Norwegian Scientific Committee for Food Safety

    2014-01-01

    Physical conditions such as water quantity, water depths, receiver capacity for pollution, currents and renewal of water, is more limited in lakes than in the sea. The consequence is that fresh water farms must be smaller. Signs of pollution from fish farms will appear at an earlier stage than in the sea, and monitoring of water quality in and outside the farm is important to ensure good conditions for the fish.

  16. Copepoda parasites in economically important fish, Mugilidae ...

    African Journals Online (AJOL)

    FUNMILAYO

    of economically important fish, both from the wild and fish farms, thus making them difficult to market. In this study, copepod parasitic investigation was carried out in gills of 856 fish mugilidae (Mugil cephalus and Liza falcipinnis) in three stations (Ganvie, Djdje and Zogbo) of Lac Nokoue lagoon. In the three stations, three ...

  17. Amaranth farming

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Kjær, Tyge; Kjærgård, Bente

    2008-01-01

    natural resources that small-scale farmers have to combat the abovementioned problems. The study identified several local and regional barriers for increasing the level of farming, production, processing and consumption. A striking and paradoxical limitation is the monopolization practices developed...

  18. Molecular farming

    NARCIS (Netherlands)

    Merck, K.B.; Vereijken, J.M.

    2006-01-01

    Molecular Farming is a new and emerging technology that promises relatively cheap and flexible production of large quantities of pharmaceuticals in genetically modified plants. Many stakeholders are involved in the production of pharmaceuticals in plants, which complicates the discussion on the

  19. Organic farming

    NARCIS (Netherlands)

    Ma, Wanglin; Ma, Chunbo; Su, Ye; Nie, Zihan

    2017-01-01

    Purpose: The purpose of this paper is to explore the factors that influence Chinese apple farmers' willingness to adopt organic farming, paying a special attention to the role of information acquisition. Design/methodology/approach: Given that the selection bias may occur when farmers themselves

  20. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States); Rosener, B. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host ``na-net.ornl.gov`` at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message ``send index`` to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user`s perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  1. NA-NET numerical analysis net

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science Oak Ridge National Lab., TN (United States)); Rosener, B. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science)

    1991-12-01

    This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host na-net.ornl.gov'' at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message send index'' to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user's perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.

  2. Mortalidade por "septicemia dos peixes tropicais" em tilápias criadas em consorciação com suínos Edwardsiella septicemia mortality in tilapia-integrated with pig in fish farming

    Directory of Open Access Journals (Sweden)

    M.C.S. Muratori

    2001-12-01

    Full Text Available Com o objetivo de estudar a variação sazonal da septicemia dos peixes tropicais provocada por Edwardsiella tarda foram observadas 50 tilápias (Oreochromis sp. no verão, 45 no outono, 55 no inverno e 105 na primavera. Os peixes doentes apresentavam opacidade de córnea, dificuldade respiratória, nado desordenado, nódulos nas brânquias e lesões hemorrágicas na pele e nadadeiras. Após três dias de observação as tilápias morriam naturalmente. Nas necrópsias foi encontrado ascite com distensão da cavidade celomática e lesões hemorrágicas e necróticas no fígado, baço e rins. No interior do tubo digestivo observou-se enterite hemorrágica. Isolou-se Edwardsiella tarda a partir de provas positivas para H2S, lisina, indol, motilidade e glicose com gás. Os índices de mortalidade foram: na primavera 69,9%, no inverno 63,6%, no verão 48,0% e no outono 40,0%.A rural property was observed for one year to obtain seasonal observations of Edwardsiella septicemia in tilapias (Oreochromis sp. from an integrated fish farm (using pig excrements as food. Fifty tilapias on summer, forty-five on autumn, fifty-five on winter and one hundred and five on spring were collected and evaluated microbiologically for the presence of Edwardsiella tarda. Samples of the external surface (skin, gills and fin, intestines and muscle were analyzed. Fishes were transported alive to the laboratory, and maintained for five days for observation. The external signs observed were opacity of cornea, respiratory difficulty, disordered swimming, nodules on gills, hemorrhagic lesions under the skin and fins and incoordination of the posterior part of the body. In general, after three days of observation, the tilapias died. At necropsy, ascites with the distension of the celomatic cavity, hemorrhagic and necrotic lesions in the liver, spleen and kidneys were found. Hemorrhagic enteritis was observed in the gut tube. Edwardsiella tarda isolated presented the following

  3. Evaluation of single cell protein for nutrition of farm animals

    Energy Technology Data Exchange (ETDEWEB)

    Oslage, H.J.; Schulz, E.

    1981-08-01

    For the production of microorganisms with high content of protein technologies on the basis of carbon rich substrates have been developed during the past years. Thus, signification of Single Cell Protein (SCP) for nutrition of farm animals has changed. While, in former times, yeasts were added only in small portions (1-2%) as vitamin supplementation today it is the aim to use microbial biomass as a protein component. The use of SCP as a feedstuff requires a careful physiological and toxicological evaluation as well as extensive investigations of possible use and frontiers of those products for farm animals. Topic of this work were bacteria, bred on methanol as well as yeasts, grown on alcanes and on whey/lactic acid respectively. SCP is preferently used as a feedstuff for poultry, pigs, calves and fishes. Digestibility and utilisation of protein is good till very good, for the a.m. animals, digestibility being between 75-93% and net protein utilisation (NPU) being between 60-76%. In rations of young animals (chicken, piglets and calves) contents of 5-10% SCP have been proved to be without any negative effect on acceptance, body gain, feed utilisation and mortality. For older animals SCP can be used as the only protein source beside the basic feedstuffs.

  4. Income Analysis in South American Domestic Camelid Farms

    Directory of Open Access Journals (Sweden)

    Francesco Ansaloni

    2013-09-01

    Full Text Available This paper analyses the production costs and income of eight groups of farms: five private farms and three belonging to the Andean rural community. These farms are located in Peru and Bolivia and breed alpacas and llama for both meat and fibre. The research is based on case studies. Each case study includes several farms, grouped according to similar characteristics: available resources; breeding techniques and geographical location. A farm economic data analysis was undertaken by determining economic budget income. Statistics and data from 2003 were analysed to determine farm resources and farm production costs, per animal head and net farm income per labour unit and livestock head. This paper is relevant as regards economic data for production systems which are more often analysed for sociological and cultural aspects and less often for economic data and identification of real productive economic data which are not generally market driven.

  5. Rapid automated method for on-site determination of sulfadiazine in fish farming: a stainless steel veterinary syringe coated with a selective membrane of PVC serving as a potentiometric detector in a flow-injection-analysis system.

    Science.gov (United States)

    Almeida, S A A; Amorim, L R; Heitor, A H; Montenegro, M C B S M; Barbosa, J; Sá, L C; Sales, M G F

    2011-12-01

    Sulfadiazine is an antibiotic of the sulfonamide group and is used as a veterinary drug in fish farming. Monitoring it in the tanks is fundamental to control the applied doses and avoid environmental dissemination. Pursuing this goal, we included a novel potentiometric design in a flow-injection assembly. The electrode body was a stainless steel needle veterinary syringe of 0.8-mm inner diameter. A selective membrane of PVC acted as a sensory surface. Its composition, the length of the electrode, and other flow variables were optimized. The best performance was obtained for sensors of 1.5-cm length and a membrane composition of 33% PVC, 66% o-nitrophenyloctyl ether, 1% ion exchanger, and a small amount of a cationic additive. It exhibited Nernstian slopes of 61.0 mV decade(-1) down to 1.0 × 10(-5) mol L(-1), with a limit of detection of 3.1 × 10(-6) mol L(-1) in flowing media. All necessary pH/ionic strength adjustments were performed online by merging the sample plug with a buffer carrier of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, pH 4.9. The sensor exhibited the advantages of a fast response time (less than 15 s), long operational lifetime (60 days), and good selectivity for chloride, nitrite, acetate, tartrate, citrate, and ascorbate. The flow setup was successfully applied to the analysis of aquaculture waters. The analytical results were validated against those obtained with liquid chromatography-tandem mass spectrometry procedures. The sampling rate was about 84 samples per hour and recoveries ranged from 95.9 to 106.9%.

  6. OK-Net Arable online knowledge platform

    DEFF Research Database (Denmark)

    Rasmussen, Ilse Ankjær; Jensen, Allan Leck; Jørgensen, Margit Styrbæk

    2017-01-01

    The complexity of organic farming requires farmers to have a very high level of knowledge and skills, but exchange on organic farming management techniques remains limited. The thematic network OK-Net Arable under Horizon 2020 has the aim to improve the exchange of innovative and traditional...... knowledge among farmers, farm advisers and scientists to increase productivity and quality in organic arable cropping in Europe. An online platform for knowledge exchange has been created, offering innovative education and end-user material as well as communication opportunities between actors. A number...... of specific tools – providing information about how to put existing knowledge from research and practice into use – have been chosen. They are presented on the platform with the possibility to find solutions, evaluate them, comment and discuss them or ask questions about them and to suggest new tools...

  7. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  8. Wind Farm Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Richard Curry; Erik Foley; DOE Project Officer - Keith Bennett

    2007-07-11

    Saint Francis University has assessed the Swallow Farm property located in Shade Township, Somerset County, Pennsylvania as a potential wind power development site. Saint Francis worked with McLean Energy Partners to have a 50-meter meteorological tower installed on the property in April 2004 and continues to conduct a meteorological assessment of the site. Results suggest a mean average wind speed at 80 meters of 17 mph with a net capacity factor of 31 - 33%. Approximate electricity generation capacity of the project is 10 megawatts. Also, the University used matching funds provided by the federal government to contract with ABR, Inc. to conduct radar studies of nocturnal migration of birds and bats during the migrations seasons in the Spring and Fall of 2005 with a mean nocturnal flight altitude of 402 meters with less than 5% of targets at altitudes of less than 125 meters. The mean nocturnal passage rate was 166 targets/km/h in the fall and 145 targets/km/h in the spring. Lastly, University faculty and students conducted a nesting bird study May - July 2006. Seventy-three (73) species of birds were observed with 65 determined to be breeding or potentially breeding species; this figure represents approximately 30% of the 214 breeding bird species in Pennsylvania. No officially protected avian species were determined to be nesting at Swallow Farm.

  9. Professional Enterprise NET

    CERN Document Server

    Arking, Jon

    2010-01-01

    Comprehensive coverage to help experienced .NET developers create flexible, extensible enterprise application code If you're an experienced Microsoft .NET developer, you'll find in this book a road map to the latest enterprise development methodologies. It covers the tools you will use in addition to Visual Studio, including Spring.NET and nUnit, and applies to development with ASP.NET, C#, VB, Office (VBA), and database. You will find comprehensive coverage of the tools and practices that professional .NET developers need to master in order to build enterprise more flexible, testable, and ext

  10. Fauna parasitária de peixes oriundos de “pesque-pague” do município de Guariba, São Paulo, Brasil = Parasitic fauna of cultivated fishes in fee fishing farm of Guariba, São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Sergio Henrique Canello Schalch

    2006-07-01

    Full Text Available Este trabalho descreve a ocorrência e a sazonalidade de parasitos em peixes de “pesque-pague” do município de Guariba, Estado de São Paulo, Brasil (21o15`22``S, 48o18`58``W e 595 m de altitude, durante o período de agosto de 2001 a julho de 2002. A presença de parasitos foi pesquisada em pacu Piaractus mesopotamicus (Characidae, carpacomum Cyprinus carpio (Cyprinidae, tilápia-do-Nilo Oreochromis niloticus (Cichlidae, híbrido tambacu (macho de P. mesopotamicus x fêmea de tambaqui-Colossoma macropomum e piraputanga Brycon hillari (Characidae. Os resultados demonstram que dos 100 peixes examinados, 15% estavam parasitados por pelo menos um dos seguintes parasitos: Trichodina sp.; helmintos monogenóides; copepoditos de Lernaea cyprinacea; L. cyprinacea adulta ou Dolops carvalhoi. Por ordem decrescente, o grau de suscetibilidade dos hospedeiros foi C. carpio, P. mesopotamicus, B. hillari, híbrido tambacu e O. niloticus. Por ordem decrescente, os parasitos encontrados foram helmintos monogenóides, Dolops carvalhoi, Trichodina sp., Lernaea cyprinacea adultas e suas formas jovens.This study describes the occurrence and the seasonality of parasites of cultivated fish from a fee fishing farm located in Guariba, São Paulo State, Brazil (21º15`22`` S, 48º18`58`` W and 595 m of altitude, from August, 2001 to July, 2002. The presence of parasiteswas researched in pacu Piaractus mesopotamicus (Characidae, common carp Cyprinus carpio (Cyprinidae, nile-tilapia Oreochromis niloticus (Cichlidae, tambacu hybrid (male of P. mesopotamicus x female of tambaqui-Colossoma macropomum and piraputanga Brycon hillari (Characidae. Results demonstrate that out of 100 fish examined, 15% were sponged for at least one of the following parasites: Trichodina sp.; monogenean helminths; copepodits of Lernaea cyprinacea; adults of L. cyprinacea; or Dolops carvalhoi. In decreasing order, the susceptibility degree of the hosts was C. carpio, P. mesopotamicus, B

  11. [Compatibility determination for farming on Clarence Cannon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a compliance document which pertains to allowing farming to be used as a habitat management tool to assist in meeting Refuge purposes at Clarence Cannon...

  12. Development of net cage acoustic alarm system

    Science.gov (United States)

    Hong, Shih-Wei; Wei, Ruey-Chang

    2004-05-01

    In recent years, the fishery production has been drastically decreased in Taiwan, mainly due to overfishing and coast pollution; therefore, fishermen and corporations are encouraged by government to invest in ocean net cage aquaculture. However, the high-price fishes in the net cage are often coveted, so incidences of fish stealing and net cage breaking were found occasionally, which cause great economical loss. Security guards or a visual monitoring system has limited effect, especially in the night when these intrusions occur. This study is based on acoustic measure to build a net cage alarm system, which includes the sonobuoy and monitor station on land. The sonobuoy is a passive sonar that collects the sounds near the net cage and transmits the suspected signal to the monitor station. The signals are analyzed by the control program on the personal computer in the monitor station, and the alarms at different stages could be activated by the sound levels and durations of the analyzed data. To insure long hours of surveillance, a solar panel is applied to charge the battery, and a photodetector is used to activate the system.

  13. First report of a swordfish (Xiphias gladius Linnaeus, 1758) beneath open-sea farming cages in the Western Mediterranean Sea.

    OpenAIRE

    ARECHAVALA-LOPEZ, P.; IZQUIERDO-GOMEZ, D.; SANCHEZ-JEREZ, P.

    2013-01-01

    An adult individual of swordfish (Xiphias gladius L.) was reported for the first time aggregated at coastal Mediterranean fish-farm facilities. This record highlights the necessity to assess the potential ecological changes on wild fish assemblages by coastal farming activity, especially on this type of endangered large migratory fish predators, which might be taken into account for further management strategies.

  14. First report of a swordfish (Xiphias gladius Linnaeus, 1758 beneath open-sea farming cages in the Western Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    P. ARECHAVALA-LOPEZ

    2013-09-01

    Full Text Available An adult individual of swordfish (Xiphias gladius L. was reported for the first time aggregated at coastal Mediterranean fish-farm facilities. This record highlights the necessity to assess the potential ecological changes on wild fish assemblages by coastal farming activity, especially on this type of endangered large migratory fish predators, which might be taken into account for further management strategies.

  15. Who cares about fish welfare?

    DEFF Research Database (Denmark)

    Ellingsen, Kristian; Grimsrud, Kristine; Nielsen, Hanne Marie

    2015-01-01

    Purpose – The purpose of this paper is threefold: first, to assess how concerned Norwegians are about fish welfare; second, to investigate Norwegians’ willingness to pay for salmon filet made from welfare-assured farmed fish with high levels of welfare; and third, to examine Norwegian opinions...... about the appropriate way to pay for better welfare standards in fish production. Design/methodology/approach – On the basis of two focus group sessions, a survey questionnaire was developed and distributed to a representative sample of 2,147 Norwegian households via e-mail. Findings – Results showed...... that the Norwegian public is concerned about fish welfare and is willing to pay a price premium for products made from welfare-assured fish. Norwegian consumers do not, however, want to be the only ones paying for fish welfare, as the main responsibility for fish welfare lies with producers and the Government...

  16. Farm Women and Work.

    Science.gov (United States)

    Sander, William

    1986-01-01

    The participation by farm women in on-farm and off-farm work is estimated and the effects of female earnings on farm family income are measured. It is shown that farm women make significant contributions to income and help manage income instability. (Author/CH)

  17. Fishing activities

    Science.gov (United States)

    Oberle, Ferdinand; Puig, Pere; Martin, Jacobo; Micallef, Aaron; Krastel, Sebastian; Savini, Alessandra

    2018-01-01

    Unlike the major anthropogenic changes that terrestrial and coastal habitats underwent during the last centuries such as deforestation, river engineering, agricultural practices or urbanism, those occurring underwater are veiled from our eyes and have continued nearly unnoticed. Only recent advances in remote sensing and deep marine sampling technologies have revealed the extent and magnitude of the anthropogenic impacts to the seafloor. In particular, bottom trawling, a fishing technique consisting of dragging a net and fishing gear over the seafloor to capture bottom-dwelling living resources has gained attention among the scientific community, policy makers and the general public due to its destructive effects on the seabed. Trawling gear produces acute impacts on biota and the physical substratum of the seafloor by disrupting the sediment column structure, overturning boulders, resuspending sediments and imprinting deep scars on muddy bottoms. Also, the repetitive passage of trawling gear over the same areas creates long-lasting, cumulative impacts that modify the cohesiveness and texture of sediments. It can be asserted nowadays that due to its recurrence, mobility and wide geographical extent, industrial trawling has become a major force driving seafloor change and affecting not only its physical integrity on short spatial scales but also imprinting measurable modifications to the geomorphology of entire continental margins.

  18. Dehydrofreezing of Fish I

    Science.gov (United States)

    Kozima, Tsuneo

    Recently, new method of removing water from perishable food were developed using dehydration sheet with material having high osmotic pressure and absorbent polymer. Dehydration sheet consist of mixture of sugar dehydrolysate and absorbent polymer covered with sem-permeable membrane, and can remove water in liquid state by contact with perishable food. Dehydration rate of fish using with dehydration sheet varied depending on species, their shape, and ambient temperature etc. Fish were dehydrated with dehydration sheet at low temperature as 0 - 5 C and frozen in cold storage room. Dehydrofrozen fish were kept it's high quality and freshness after thawing, ATPase activity of fish muscle was kept at high level after dehydrofreezing in the case of cod and alaska pollack, and flesh color of farming salmon was kept after thawing.

  19. Vaccination in Fish

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar

    significant losses in aquacultural enterprises but vaccination methods implemented since the 1990s have demonstrated their role as one of the most efficient disease control strategies. These have been particularly successful with regard to bacterial diseases in Norwegian salmon farming where multivalent...... vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...

  20. Mycobacterial infection in farmed turbot Scophthalmus maximus.

    Science.gov (United States)

    dos Santos, N M S; do Vale, A; Sousa, M J; Silva, M T

    2002-11-07

    Mycobacteriosis (piscine tuberculosis) has been reported to affect a wide range of freshwater and marine fish species; however, this is the first report describing mycobacterial infections in turbot Scophthalmus maximus. High numbers of granulomas were initially observed in the organs of moribund farmed turbot. Bacteriological analysis of organs with granulomas led to the isolation of Mycobacterium marinum. Further analysis, to determine the prevalence of the infection in the farm and to identify its source, showed the occurrence of a dual infection by M. marinum and M. chelonae. The presence of Nocardia sp. in some of the fish infected with mycobacteria was also detected. The presence of granulomas in internal organs of apparently healthy fish indicated a high prevalence of the disease, a conclusion that was supported by isolating mycobacteria from all fish with or without granulomas. The infection was probably responsible for the mortality observed (approximately 2% mo(-1)), as most of the recently dead fish presented high numbers of granulomas and isolation of mycobacteria was possible from all of the fish. The isolation of M. marinum from the inlet water suggested this as the most plausible source for the infection occurring in the farm.

  1. women ensuring nutrition security through fish farming

    African Journals Online (AJOL)

    These women face several constraints while participating in fisheries activities. Therefore agricultural extension agents should provide information and technology that will sensitize the women to increase their production capabilities for sustainable protein nutrition security in the country. African Journal of Livestock ...

  2. Selectivity of penaeid trap nets used in south eastern Australia

    Directory of Open Access Journals (Sweden)

    Matt K. Broadhurst

    2004-09-01

    Full Text Available Two experiments were done to estimate the selectivity of commercial and modified trap-net configurations in New South Wales (NSW, southeastern Australia. In the first experiment, a commercial trap net made entirely from 25 mm mesh and designed for use in shallow water was alternatively fished with a fine-meshed (9.5 mm netting trap net (used as a control. In the second experiment, two trap-net configurations designed for use in deeper water and comprising the same anterior section (made from 25 mm mesh, but with different bunts made from (i the conventional 25 mm mesh and (ii 31 mm mesh were alternately fished against the control. Both of the conventional trap nets (comprising 25 mm mesh throughout had low amounts of bycatch and similarly selected eastern king Penaeus plebejus, greasyback Metapenaeus bennettae and school prawns Metapenaeus macleayi across narrow selection ranges (< 3.4 mm and at 50% retention lengths (between 18.53 and 21.50 mm that were larger than the average commercially-accepted sizes (15-17 mm CL. Analyses of the selectivities and relative efficiencies of the trap-net configurations comprising the 25 and 31 mm bunts showed no benefit, in terms of maintaining prawn catches and reducing unwanted bycatch, associated with increasing mesh size in these gears. The utility of trap nets for selectively harvesting penaeids is discussed. We conclude that this type of fishing gear appears to have few deleterious impacts.

  3. Integration of Rural Aquaculture into Small Scale Farming Systems ...

    African Journals Online (AJOL)

    This article reviewed the necessity and the importance of integration of aquaculture into small hold farming systems, based on seasonality, availability of labour and inputs. As fish production in small holdings is generally limited by the quantity and quality of inputs to the pond. The timing of labour availability and other farm ...

  4. Fish Allergy

    Science.gov (United States)

    ... Teens a Voice in Health Care Decisions Fish Allergy KidsHealth > For Parents > Fish Allergy Print A A ... Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the same ...

  5. Horizontal and vertical distribution of sea lice larvae (Lepeophtheirus salmonis) in and around salmon farms in the Bay of Fundy, Canada.

    Science.gov (United States)

    Nelson, E J; Robinson, S M C; Feindel, N; Sterling, A; Byrne, A; Pee Ang, K

    2017-11-21

    The sea louse, Lepeophtheirus salmonis, is parasitic to salmonid species in the Northern Hemisphere and has become a widespread biological and economic problem for the salmon farming industry. A better understanding is needed of their spatial distribution and early life history to disrupt the life cycle of the sea louse. In this study, sea lice larval densities within salmon farms, between salmon farms and reference sites, and at various depths were quantified using both plankton pumps and plankton nets. Farm sites exhibited significantly higher densities than reference sites; however, these densities dropped an order of magnitude at a distance of 100 m from the cages. The majority of the larvae captured in the study were nauplii (93%), and densities ranged from 0 to 10 larvae/m3 . Free-swimming sea lice larvae were found to exhibit a diel cycle where nauplii larvae were in deeper waters (10-17 m) during the day and in surface waters (1-6 m) during the night. The results of this study suggest that the early life-history stages of sea lice originate from and may remain close to active salmon farms, creating a self-sustaining population. © 2017 Her Majesty the Queen in Right of Canada. Journal of Fish Diseases © 2017 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Fisheries and Oceans of Canada.

  6. Strategic Data Farming

    National Research Council Canada - National Science Library

    Duong, Deborah

    2008-01-01

    Strategic Data Farming: *Strategic Data Farming may be employed in the first phase of the iterative model-game-model process -Strategic Data Farming is a way to explore how a player or an agent may succeed in a wargame...

  7. WaveNet

    Science.gov (United States)

    2015-10-30

    Coastal Inlets Research Program WaveNet WaveNet is a web-based, Graphical-User-Interface ( GUI ) data management tool developed for Corps coastal...generates tabular and graphical information for project planning and design documents. The WaveNet is a web-based GUI designed to provide users with a...data from different sources, and employs a combination of Fortran, Python and Matlab codes to process and analyze data for USACE applications

  8. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...... use of CP-nets — because it means that the function representation and the translations (which are a bit mathematically complex) no longer are parts of the basic definition of CP-nets. Instead they are parts of the invariant method (which anyway demands considerable mathematical skills...

  9. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  10. Programming NET Web Services

    CERN Document Server

    Ferrara, Alex

    2007-01-01

    Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

  11. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    -net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... a method which makes it possible to associate auxiliary information, called annotations, with tokens without modifying the colour sets of the CP-net. Annotations are pieces of information that are not essential for determining the behaviour of the system being modelled, but are rather added to support...

  12. Design tool for offshore wind farm cluster planning

    OpenAIRE

    HASAGER, Charlotte Bay; Madsen, Peter Hauge; Giebel, Gregor; Réthoré, Pierre-Elouan; Hansen, Kurt Schaldemose; Badger, Jake; Pena Diaz, Alfredo; Volker, Patrick; Badger, Merete; Karagali, Ioanna; Nicolaos Antonio CUTULULIS; Maule, Petr; Schepers, Gerard; Wiggelinkhuizen, J; Cantero, Elena

    2015-01-01

    In the framework of the FP7 project EERA DTOC: Design Tool for Offshore wind farm Cluster, a new software supporting the planning of offshore wind farms was developed, based on state-of-the-art approaches from large scale wind potential to economic benchmarking. The model portfolio includes WAsP, FUGA, WRF, Net-Op, LCoE model, CorWind, FarmFlow, EeFarm and grid code compliance calculations. The development is done by members from European Energy Research Alliance (EERA) and guided by several ...

  13. Design tool for offshore wind farm cluster planning

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Madsen, Peter Hauge; Giebel, Gregor

    2015-01-01

    In the framework of the FP7 project EERA DTOC: Design Tool for Offshore wind farm Cluster, a new software supporting the planning of offshore wind farms was developed, based on state-of-the-art approaches from large scale wind potential to economic benchmarking. The model portfolio includes WAs......P, FUGA, WRF, Net-Op, LCoE model, CorWind, FarmFlow, EeFarm and grid code compliance calculations. The development is done by members from European Energy Research Alliance (EERA) and guided by several industrial partners. A commercial spin-off from the project is the tool ‘Wind & Economy’. The software...

  14. extent of use of ict by fish farmers in isoko agricultural zone of delta ...

    African Journals Online (AJOL)

    Mr. TONY A

    of ICT facilities? What activities of fish farming do fish famers use ICT facilities? What demographic variables influence the use of ICT facilities? The broad objective of .... Marital Status. Single. Married. Education. No formal education. Primary. Secondary. Tertiary. Adult education. Fish farming experience. Less than 5 years.

  15. Organic waste reclamation, recycling and re-use in integrated fish ...

    African Journals Online (AJOL)

    The purpose of this paper is to create awareness on the significance of integrated fish farming in organic waste reclamation, recycling and re-use. Example of integrated fish farming practiced at a micro-level in the Niger Delta of Nigeria is crop-snailry-poultry (Chicken) – livestock (pig) – cum-fish production. In this system ...

  16. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available Is it possible to develop a building that uses a net zero amount of water? In recent years it has become evident that it is possible to have buildings that use a net zero amount of electricity. This is possible when the building is taken off...

  17. SolNet

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Vajen, Klaus; Bales, Chris

    2014-01-01

    SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...

  18. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  19. Economische gevolgen van de omschakeling naar een biologische bedrijfsvoering voor Aver Heino = Switching to organic farming: the economic repercussions for Aver Heino

    NARCIS (Netherlands)

    Hutschemaekers, B.J.H.; Haan, de M.H.A.; Pinxterhuis, J.B.

    2004-01-01

    Switching to organic farming: the economic repercussions for Aver Heino The economic repercussions of a switch to organic farming on Aver Heino were investigated by modelling, using technical data for 1997 (conventional farming) and 2000 (organic).Compared with 1997, in 2000 the net farm profit was

  20. Mobilizing local safety nets for enhanced adaptive capacity to ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    22 avr. 2016 ... In Zimbabwe, the increased frequency of drought, flash floods, and unpredictable rainfall has added to recurrent food deficits for poor households who depend on rainfed farming on nutrient poor soils. This brief explores how the erosion of Zunde raMambo — a traditional community safety net mechanism ...

  1. Influence of cage farming on feeding and reproductive aspects of Pimelodus maculatus Lacépède, 1803 (Siluriformes: Pimelodidae in the Chavantes reservoir, Brazil - doi: 10.4025/actascibiolsci.v36i1.

    Directory of Open Access Journals (Sweden)

    Heleno Brandão

    2013-09-01

    Full Text Available This study evaluated the diet and reproductive aspects of the population of Pimelodus maculatus around net cage fish farming in order to assess the possible impacts of this activity. Monthly collections were performed from March 2008 to February 2009 on two populations: one close to the net cages (NC and one from an area not influenced by these cages denominated the “reference site” (RS. Results of the Alimentary Index (AI, Gonadosomatic Index (GSI, reproductive potential and histological analysis were obtained for both NC and RS populations. The population from NC used leftover food (ration that escapes from net cages as the main food item (99.3%. For the RS population, the detritus item was the more important food source (51.7%. The Detrended Correspondence Analysis (DCA showed that the use of food resources was different between the two sites. The reproductive period of the species (indicated by the GSI revealed that the population of the NC showed an extended reproductive period compared to RS. The histology of the ovaries indicated that the specimens in the NC were spawning capable. This study indicates that fish farming activities influence the species P. maculatus in the Chavantes reservoir by adding a new resource to the food web.

  2. Business plan Tilapia cage farming in Tete Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Meer, van der Magnus; Brouwer, Herman

    2015-01-01

    Tete province offers great opportunities for cage farming of tilapia in Lake Cahora Bassa. The climate and water quality are favourable for fish production, and the fast economic developments in the region will facilitate fish sales. In Tete tilapia (pende) is highly valued food. Major markets for

  3. The Technical Efficiency of Specialised Milk Farms: A Regional View

    Directory of Open Access Journals (Sweden)

    Jindřich Špička

    2014-01-01

    Full Text Available The aim of the article is to evaluate production efficiency and its determinants of specialised dairy farming among the EU regions. In the most of European regions, there is a relatively high significance of small specialised farms including dairy farms. The DEAVRS method (data envelopment analysis with variable returns to scale reveals efficient and inefficient regions including the scale efficiency. In the next step, the two-sample t-test determines differences of economic and structural indicators between efficient and inefficient regions. The research reveals that substitution of labour by capital/contract work explains the variability of the farm net value added per AWU (annual work unit income indicator by more than 30%. The significant economic determinants of production efficiency in specialised dairy farming are farm size, herd size, crop output per hectare, productivity of energy, and capital (at α=0.01. Specialised dairy farms in efficient regions have significantly higher farm net value added per AWU than inefficient regions. Agricultural enterprises in inefficient regions have a more extensive structure and produce more noncommodity output (public goods. Specialised dairy farms in efficient regions have a slightly higher milk yield, specific livestock costs of feed, bedding, and veterinary services per livestock unit.

  4. The technical efficiency of specialised milk farms: a regional view.

    Science.gov (United States)

    Spička, Jindřich; Smutka, Luboš

    2014-01-01

    The aim of the article is to evaluate production efficiency and its determinants of specialised dairy farming among the EU regions. In the most of European regions, there is a relatively high significance of small specialised farms including dairy farms. The DEAVRS method (data envelopment analysis with variable returns to scale) reveals efficient and inefficient regions including the scale efficiency. In the next step, the two-sample t-test determines differences of economic and structural indicators between efficient and inefficient regions. The research reveals that substitution of labour by capital/contract work explains the variability of the farm net value added per AWU (annual work unit) income indicator by more than 30%. The significant economic determinants of production efficiency in specialised dairy farming are farm size, herd size, crop output per hectare, productivity of energy, and capital (at α = 0.01). Specialised dairy farms in efficient regions have significantly higher farm net value added per AWU than inefficient regions. Agricultural enterprises in inefficient regions have a more extensive structure and produce more noncommodity output (public goods). Specialised dairy farms in efficient regions have a slightly higher milk yield, specific livestock costs of feed, bedding, and veterinary services per livestock unit.

  5. The Adipose Tissue in Farm Animals

    DEFF Research Database (Denmark)

    Sauerwein, Helga; Bendixen, Emoke; Restelli, Laura

    2014-01-01

    and immune cells. The scientific interest in adipose tissue is largely based on the worldwide increasing prevalence of obesity in humans; in contrast, obesity is hardly an issue for farmed animals that are fed according to their well-defined needs. Adipose tissue is nevertheless of major importance...... in these animals, as the adipose percentage of the bodyweight is a major determinant for the efficiency of transferring nutrients from feed into food products and thus for the economic value from meat producing animals. In dairy animals, the importance of adipose tissue is based on its function as stromal...... and metabolic disorders. We herein provide a general overview of adipose tissue functions and its importance in farm animals. This review will summarize recent achievements in farm animal adipose tissue proteomics, mainly in cattle and pigs, but also in poultry, i.e. chicken and in farmed fish. Proteomics...

  6. The effect of netting solidity ratio and inclined angle on the hydrodynamic characteristics of knotless polyethylene netting

    Science.gov (United States)

    Tang, Hao; Hu, Fuxiang; Xu, Liuxiong; Dong, Shuchuang; Zhou, Cheng; Wang, Xuefang

    2017-10-01

    Knotless polyethylene (PE) netting has been widely used in aquaculture cages and fishing gears, especially in Japan. In this study, the hydrodynamic coefficient of six knotless PE netting panels with different solidity ratios were assessed in a flume tank under various attack angles of netting from 0° (parallel to flow) to 90° (perpendicular to flow) and current speeds from 40 cm s-1 to 130 cm s-1. It was found that the drag coefficient was related to Reynolds number, solidity ratio and attack angle of netting. The solidity ratio was positively related with drag coefficient for netting panel perpendicular to flow, whereas when setting the netting panel parallel to the flow the opposite result was obtained. For netting panels placed at an angle to the flow, the lift coefficient reached the maximum at an attack angle of 50° and then decreased as the attack angle further increased. The solidity ratio had a dual influence on drag coefficient of inclined netting panels. Compared to result in the literature, the normal drag coefficient of knotless PE netting measured in this study is larger than that of nylon netting or Dyneema netting.

  7. Backyard Fish Farmers Information needs in Osun State, Nigeria

    OpenAIRE

    Ogunlade, I.

    2008-01-01

    The need for increase in fish production in order to improve protein intake by Nigerians led to this study. The study analyzed information needs of backyard fish farmers in Osun State, Nigeria. Specifically, the study investigated the socio-economic characteristics of backyard fish farmers, frequency of performance, importance and difficulties of management practices as well as the constraints facing backyard fish farming. Questionnaire was used to elicit information from 70 backyard fish far...

  8. Fish farmers' perceptions of constraints affecting aquaculture ...

    African Journals Online (AJOL)

    The study focused on fish farmers' perceptions of constraints affecting aquaculture development in Akwa-Ibom State of Nigeria. Random sampling procedure was used to select 120 respondents from whom primary data was collected. Data analysis was with the aid of descriptive statistics. Results show that fish farming ...

  9. Fish Farmers' Perception of Climate change impact on fish ...

    African Journals Online (AJOL)

    ... be a consequence of the negative impact of climate change. This study concluded that there's a need for the active involvement of stakeholders in developing policies relating to climate change mitigation and beneficial response strategies to global warming. Keywords: Climate change, fish farming, impact and perception.

  10. Fish Farmers' Perception of Climate change impact on fish ...

    African Journals Online (AJOL)

    Michael Madukwe

    This study concluded that there's a need for the active involvement of stakeholders in developing policies relating to climate change mitigation and beneficial response strategies to global warming. Keywords: Climate change, fish farming, impact and perception. Introduction. The Intergovernmental Panel on Climate Change ...

  11. Fish Farmers' Perception of Climate change impact on fish ...

    African Journals Online (AJOL)

    Michael Madukwe

    Keywords: Climate change, fish farming, impact and perception. Introduction ... to global warming. According to Raymond and Victoria (2008), climate change has the potential to affect all natural systems thereby becoming a threat to human ... decline and deal with emerging issues such as demand for renewable energy.

  12. Optimization of fishing for stock enhancement of Rutilis rutilus and Scardinius erythropththalmus in forage fish-deficient Tunisian reservoirs.

    Science.gov (United States)

    Mili, Sami; Ennouri, Rym; Laouar, Houcine; Aleya, Lotfi

    2017-11-04

    Twenty specially designed fishing nets were used to catch broodstock of the forage fish roach and rudd (Rutilus rutilus and Scardinius erythrophthalmus). The monofilament gill nets were of different mesh sizes (18, 22, 24, and 26 mm) but of identical dimensions (4 × 50 m). The fish, caught in Sidi Salem reservoir in 2014, amounted to a total of 8901 roach and rudd caught at 41 different times; 3335 broodstock forage fish were transferred to 11 forage fish-deficient Tunisian reservoirs. The best yields (0.464 fish/m2) were obtained with fishing gear fitted with 18-mm mesh size; however, fish mortality with this net was very high, exceeding 83.36%. The greatest efficiency was obtained using nets of 22- and 24-mm mesh with a number of fish per unit effort (NPUE) of 0.181 and 0.173 fish/m2, and a mortality of 54.34 and 53.85%, respectively. Gill nets of 26-mm mesh size were inappropriate (lowest yield 0.129 fish/m2). Length of rudd and roach at first maturity and Gonadosomatic index (GSI) were measured, indicating that all transferred fish were mature. Transfer techniques were improved by holding the captured fish for 5 days before release into the host reservoir.

  13. Pro NET Best Practices

    CERN Document Server

    Ritchie, Stephen D

    2011-01-01

    Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

  14. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  15. Instant Lucene.NET

    CERN Document Server

    Heydt, Michael

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A step-by-step guide that helps you to index, search, and retrieve unstructured data with the help of Lucene.NET.Instant Lucene.NET How-to is essential for developers new to Lucene and Lucene.NET who are looking to get an immediate foundational understanding of how to use the library in their application. It's assumed you have programming experience in C# already, but not that you have experience with search techniques such as information retrieval theory (although there will be a l

  16. Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Musall, Eike

    2010-01-01

    and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...... parameters used in the calculations are discussed and the various renewable supply options considered in the methodologies are summarised graphically. Thus, the paper helps to understand different existing approaches to calculate energy balance in Net ZEBs, highlights the importance of variables selection...

  17. PhysioNet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

  18. NetSig

    DEFF Research Database (Denmark)

    Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

    2018-01-01

    Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

  19. Water quality and fish diversity of Federal University of Agriculture ...

    African Journals Online (AJOL)

    Water quality and fish diversity of Federal University of Agriculture Abeokuta reservoir. ... At the river channel and the floodplain sites, traps, cast nets (2.55cm mesh), seine nets (2.55 x 2 cm mesh), monofilament nylon gillnets (15.55 cm mesh), and hook ... The water quality parameters were favourable for fish production.

  20. Changes in productivity and profitability of wool-growing farms that follow recommendations from agricultural and veterinary studies.

    Science.gov (United States)

    Lean, G R; Vizard, A L; Ware, J K

    1997-10-01

    To estimate the changes in productivity and profitability in a group of wool-growing farms as they adopted major recommendations from agricultural and veterinary studies. FARMS: Four wool-growing farms in south western Victoria were selected from the clients of the Mackinnon Project, a farm consultancy service run from the University of Melbourne. Each farm had closely followed recommended procedures, kept comprehensive financial and physical records and had been clients for at least 5 years. The comparison group was the South Western Victoria Monitor Farm Project (SWVMFP), about 45 farms in the same region as the study farms that were monitored annually by Agriculture Victoria. For a 7-year period, the financial and physical performance of both groups of farms was estimated. Stocking rate, wool production, gross farm income, farm operating costs, net farm income and return on assets were compared. Mean gross farm income of the four study farms steadily rose from 86% of the average SWVMFP farm before the adoption of recommendations to an average of 155%. During the same period, net farm income rose from 70% to 207% of the average of the SWVMFP. Return on asset of the four farms rose irregularly from 26% to 145% of the average of the SWVMFP. Farm operating costs on the four farms were higher than for the SWVMFP group, but the ratio of costs remained relatively constant. The adoption of proven research results was associated with large increases in net farm income. An increase in gross income, rather than a reduction in costs was the main reason for this. Research results offer a way to increase the financial viability of wool-growing farmers, many of whom are currently unable to maintain their lifestyle, resources and infrastructure.

  1. TideNet

    Science.gov (United States)

    2015-10-30

    query tide data sources in a desired geographic region of USA and its territories (Figure 1). Users can select a tide data source through the Google Map ...select data sources according to the desired geographic region. It uses the Google Map interface to display data from different sources. Recent...Coastal Inlets Research Program TideNet The TideNet is a web-based Graphical User Interface (GUI) that provides users with GIS mapping tools to

  2. Building Neural Net Software

    OpenAIRE

    Neto, João Pedro; Costa, José Félix

    1999-01-01

    In a recent paper [Neto et al. 97] we showed that programming languages can be translated on recurrent (analog, rational weighted) neural nets. The goal was not efficiency but simplicity. Indeed we used a number-theoretic approach to machine programming, where (integer) numbers were coded in a unary fashion, introducing a exponential slow down in the computations, with respect to a two-symbol tape Turing machine. Implementation of programming languages in neural nets turns to be not only theo...

  3. Interaction Nets in Russian

    OpenAIRE

    Salikhmetov, Anton

    2013-01-01

    Draft translation to Russian of Chapter 7, Interaction-Based Models of Computation, from Models of Computation: An Introduction to Computability Theory by Maribel Fernandez. "In this chapter, we study interaction nets, a model of computation that can be seen as a representative of a class of models based on the notion of 'computation as interaction'. Interaction nets are a graphical model of computation devised by Yves Lafont in 1990 as a generalisation of the proof structures of linear logic...

  4. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  5. The Skin-Mucus Microbial Community of Farmed Atlantic Salmon (Salmo salar)

    OpenAIRE

    Giusi Minniti; Live Heldal Hagen; Davide Porcellato; Sven Martin Jørgensen; Pope, Phillip B.; Gustav Vaaje-Kolstad

    2017-01-01

    The skin of the teleost is a flexible and scaled structure that protects the fish toward the external environment. The outermost surface of the skin is coated with mucus, which is believed to be colonized by a diverse bacterial community (commensal and/or opportunistic). Little is known about such communities and their role in fish welfare. In aquaculture, fish seem to be more susceptible to pathogens compared to wild fish. Indeed common fish farming practices may play important roles in prom...

  6. Conventional, Partially Converted and Environmentally Friendly Farming in South Korea: Profitability and Factors Affecting Farmers’ Choice

    Directory of Open Access Journals (Sweden)

    Saem Lee

    2016-07-01

    Full Text Available While organic farming is well established in Europe a nd USA, it is still catching up in Asian countries. The government of South Korea has implemented environmentally friendly farming that encompasses organic farming. Despite the promotion of environmentally friendly farming, it still has a low share in South Korea and partially converted farming has emerged in some districts of South Korea. However, the partially converted farming has not yet been investigated by the government. Thus, our study implemented a financial analysis to compare the annual costs and net returns of conventional, partially converted and environmentally friendly farming in Gangwon Province. The result showed that environmentally friendly farming was more profitable with respect to farm net returns. To find out the factors affecting the adoption of environmentally friendly farming, multinomial logistic regression was implemented. The findings revealed that education and subsidy positively and significantly influenced the probability of farmers’ choice on partially converted and environmentally friendly farming. Farm size had a negative and significant relationship with only environmentally friendly farming. This study will contribute to future policy establishment for sustainable agriculture as recommended by improving the quality of fertilizers, suggesting the additional investigation associated with partially converted farmers.

  7. Production and economic results of intensive carp (Cyprinus Carpio farming in Serbia

    Directory of Open Access Journals (Sweden)

    Rajić Zoran

    2016-01-01

    Full Text Available Carp production in Serbia is traditionally conducted in large area fish farms under a semi-intensive farming system. Total area under fish farms in Serbia amounts to approximately 11 thousand hectares, with 8.5 thousand hectares being under exploitation each year. In 2004, a significant intensification of production began at fish farms in Serbia which have traditionally organized their production under a classic semi-intensive farming system. Intensification of production was undertaken with partial or complete feeding with pelleted complete feeds. That way carp production per area unit (kg/ha was increased by over 50%. Apart from intensification by means of using the complete extruded feeds, construction of specialized fish farms for intensive carp production started in 2003. At this moment (2016 their area amounts to several hundred hectares. Data from intensive carp fish farms indicate that production of one- and two-year fish has been approximately 3t/ha in the period from 2003 until today, with a mild increase during the last couple of years. With the purpose of determining the cost effectiveness of investments in fish ponds for intensive carp production two organization-economic models have been analyzed in the study. The models have been formed based on in line with the specific features of the Serbian carp farming, which has been analyzed both on the basis of data obtained from the scientific and specialist literature but also from the production practice. Models of intensive carp production in technical and production sense have been defined in the study and production plans have been prepared. Therefore, based on such defined models, dynamic methods have been prepared for assessment of economic effects of the investments. The results of the analysis have demonstrated that investment in intensive carp production on 10ha fish farm is not, and on 50ha fish farm is barely economically justifiable, as well as methods for improvement of

  8. Fish Kill in the Philippines—Déjà Vu

    Directory of Open Access Journals (Sweden)

    Gil Jacinto

    2011-12-01

    Full Text Available Almost ten years ago today, the country woke up toscreaming headlines— “Massive Fish Kill inPangasinan” or something akin to that. The fish killphenomenon, familiar to fishers in freshwater andcoastal bodies of water where fish farming was beingpursued, was suddenly manifested at a scale that hadheretofore not been experienced.

  9. Homestead fish farmers' production profile in Osun state, Nigeria ...

    African Journals Online (AJOL)

    Homestead fish farming in the Nigeria is carried out by small scale operators in small fresh water ponds.It is increasingly becoming a popular way for people to raise their own source of edible fish right in their backyard. Despite the efforts towards Agricultural development in Osun State, the fishing industry is still in a poor ...

  10. Prebiotic (Mannanoligosaccharide- MOS in fish nutrition: effects on nile-tilapia Oreochromis niloticus performance

    Directory of Open Access Journals (Sweden)

    Flávio Endrigo Cechim

    2012-12-01

    Full Text Available World fish production are growing about 10% a year and Brazil presents potential to be the first one in fish production until 2030. However, intensification of aquaculture production systems expose fish to numerous stressors such as poor water quality, crowding, handling and transport which may negatively affect their growth and and limit profitability of aquaculture systems. This current setup favors the use of dietary prebiotics for management of farmed fish as environmentally friendly practice. This study was set out to determine de effects of increasing levels of mannanoligosccharides (MOS on growth of juvenile Nile tilapia (Oreochromis niloticus. Fish (12.62 ± 0.38 were randomly distributed into 16 cages (0.25m3 polyvinyl chloride; 20 fish per cage, inside four 5m3 net-cage at Salto Caxias Hydroeletric water reservoir (Boa Vista da Aparecida, PR. Fish were fed during 60 days with a commercial diet (32%CP supplemented with 0.0 (control; 0.2; 0.4 and 0.8% dietary MOS (n=4. Water quality parameters (temperature, pH and dissolved oxygen were monitored during trial. After 60 days feeding trial, fish were fasted for 24 hours and sedated for biometrical parameters to evaluate growth parameters. It was observed no influence (p>0.05 of MOS supplementation on Nile tilapia growth parameters (weight gain, feed conversion rate, specific growth rate as well as for hepatosomatic index. Fish fed 0.4% dietary MOS showed increased (p<0.05 feed consumption (76.74 ± 3.98 when compared to fish fed control (unsupplemented diet (69.31 ± 1.11. MOS are indigestible glucomannoproteins, which provide mannose substrate upon which pathogenic gut bacteria selectively attach and prevents formation of mixed colonies leading to better gut health by increasing regularity, height and integrity of the gut villi and consequent better utilization and absorption of nutrients. Several authors found positive effects of MOS supplementation on fish growth and at same time, others

  11. Diversity of selective and non-selective fishing gear and their impact ...

    African Journals Online (AJOL)

    user

    This survey was conducted in Al-Kalakla Fishery (KF) and Jabel Awlia Dam Fishery (JADF) in the White. Nile River, Khartoum state to identify the selective and non-selective fishing gear. The results showed the selective fishing gear represented by gill-nets and seine nets (beach nets) in both fisheries with clear variation in ...

  12. Diversity of selective and non-selective fishing gear and their impact ...

    African Journals Online (AJOL)

    This survey was conducted in Al-Kalakla Fishery (KF) and Jabel Awlia Dam Fishery (JADF) in the White Nile River, Khartoum state to identify the selective and non-selective fishing gear. The results showed the selective fishing gear represented by gill-nets and seine nets (beach nets) in both fisheries with clear variation in ...

  13. Applicability of Perinereis aibuhitensis Grube for fish waste removal from fish cages in Sanggou Bay, P. R. China

    NARCIS (Netherlands)

    Fang, Jinghui; Jiang, Zengjie; Jansen, Henrice M.; Hu, Fawen; Fang, Jianguang; Liu, Yi; Gao, Yaping; Du, Meirong

    2017-01-01

    The present study investigated the applicability of integrated polychaete-fish culture for fish waste removal to offset negative impact induced by organic benthic enrichment. A field study demonstrated that deposition rate was significantly higher underneath the fish farm than that in control

  14. Contaminación producida por piscicultura intensiva en lagunas andinas de Junín, Perú/Pollution produced by intensive fish farming in Andean lagoons, Junín, Peru

    National Research Council Canada - National Science Library

    Mauro Mariano; Pedro Huaman; Egma Mayta; Haydee Montoya; Magda Chanco

    2010-01-01

    ...%). Palabras clave: contaminación, lagunas andinas, cultivo de truchas, especies introducidas. Abstract We report the changes produced by intensive farming of rainbow trout Oncorhynchus mykiss in seven Andean lagoons. The observations were made in 1996 and between 2002-2007 and allowed to observe the deterioration of the lakes, characteri...

  15. A survey of fish species diversity and abundance in the White Volta ...

    African Journals Online (AJOL)

    The study was conducted in the White Volta River at Nawuni to identify the fishing gears used by the fishermen, assess fish species composition and their relative abundance. The results indicated that fishing gears such as gill nets, traps and hook-and-line were used. Most of the net mesh sizes used by the fishermen did ...

  16. 76 FR 77490 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-12-13

    ... are ineffective. Fyke nets with wing walls and fish traps will be deployed for effective sampling... management practices and follow NMFS electrofishing guidelines to minimize sampling effects on fish. All... by trammel net. No indirect mortality is anticipated during fish capture, sampling and release...

  17. A comparison of oxolinic acid concentrations in farmed and laboratory held rainbow trout ( Oncorhynchus mykiss ) following oral therapy

    DEFF Research Database (Denmark)

    Coyne, R.; Samuelsen, O.; Kongshaug, H.

    2004-01-01

    Plasma oxolinic acid (OXA) concentrations were measured in fish from a cage of farmed rainbow trout (Oncorhynchus mykiss) 1 day after the termination of medication. The fish were experiencing significant mortalities and following a diagnosis of vibriosis, OXA had been orally administered at 50 mg...... laboratory held rainbow trout (O. mykiss) following the administration of OXA under similar conditions of salinity, temperature and dosing regimen. In these laboratory held fish, the mean plasma OXA concentration was 0.133±0.068 mg/l. The major difference between the distributions of OXA concentrations...... in the farm and laboratory populations was in the extent of fish to fish variation observed. In the healthy farmed fish, the percentage coefficient of variation (%CV) was 97% compared to a %CV of 51% in the laboratory held fish. The patterns of the daily mortality in the farmed population were analysed from...

  18. Fish Farmers' Perception of Climate change impact on fish ...

    African Journals Online (AJOL)

    Michael Madukwe

    climate change problems through deforestation thereby causing desertification, soil erosion ... change adaptation. In view of prevailing evidence, adaptation to climate change is subject to modification of solar net drier to meet fish smoking needs. In alternative is ... natural climate variability observed over comparable time ...

  19. Highly commercial farms in family farming in Poland

    OpenAIRE

    Karwat-Woźniak, Bożena; Chmieliński, Paweł

    2007-01-01

    Highly commercial farms – overview. The distribution of highly commercial farms. Distribution of highly commercial farms according to social and demographic characteristics of farm managers. The distribution of highly commercial farms in size groups. Highly commercial farms in agricultural structures. Regional differences in the formation of the group of highly commercial Farms. Prospects of speeding up the development of highly commercial farms and strengthening their position in agriculture...

  20. Fish losses due to bacterial flora and infections of fishes in Kainji ...

    African Journals Online (AJOL)

    Economically, spoilage in either capture or culture fisheries do result into reduction in the market price of fish leading to an economic loss in the fish industry venture. Proper recommendations were made to alleviate this and promote economically sustainable fisheries in Nigeria as government thinks of privatising her farms.

  1. Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries

    DEFF Research Database (Denmark)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, Kenneth Darwin

    2012-01-01

    Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm...... to juvenile fish raised in carp nurseries....

  2. National Farm Medicine Center

    Science.gov (United States)

    ... WI Infant Study Cohort Prevention Agricultural Safety Consulting Agritourism Farm MAPPER Lyme Disease ROPS Rebate Skin Cancer ... populations. Current safety and health priorities include children, agritourism, beginning farmers and ranchers, and injury surveillance. Farm ...

  3. Organic farming at the farm level

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Madsen, Niels; Ørum, Jens Erik

    The purpose of this report is to present possible impacts of new technology and changes in legislation on the profitability of different types of organic farms. The aim is also to look at both the current and future trends in the organic area in Denmark. The farm level analyses are carried out...... as part of a larger project entitled “Economic analyses of the future development of organic farming – effects at the field, farm, sector and macroeconomic level”. The project links effects at the field-level with analyses at the farm level. These effects are then used in sector and macroeconomic analyses......, which are described in other reports from Food and Resource Economic Institute (Jacobsen, 2005 and Andersen et al., 2005). This gives coherent results from the field to the macroeconomic level regarding changes in technology and legislation....

  4. La plataforma .NET

    OpenAIRE

    Fornas Estrada, Miquel

    2008-01-01

    L'aparició de la plataforma .NET Framework ha suposat un canvi molt important en la forma de crear i distribuir aplicacions, degut a que incorpora una sèrie d'innovacions tècniques i productives que simplifiquen molt les tasques necessàries per desenvolupar un projecte. La aparición de la plataforma. NET Framework ha supuesto un cambio muy importante en la forma de crear y distribuir aplicaciones, debido a que incorpora una serie de innovaciones técnicas y productivas que simplifican mucho...

  5. Biological Petri Nets

    CERN Document Server

    Wingender, E

    2011-01-01

    It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

  6. Forest farming practices

    Science.gov (United States)

    J.L. Chamberlain; D. Mitchell; T. Brigham; T. Hobby; L. Zabek; J. Davis

    2009-01-01

    Forest farming in North America is becoming popular as a way for landowners to diversify income opportunities, improve management of forest resources, and increase biological diversity. People have been informally "farming the forests" for generations. However, in recent years, attention has been directed at formalizing forest farming and improving it...

  7. Values in Organic Farming

    DEFF Research Database (Denmark)

    Kjærgård, Bente; Pedersen, Kirsten Bransholm; Land, Birgit

    The study focuses on the recent debate about what is, or what constitutes, organic farming and what is the right path for organic farming in the future. The study is based on a critical discourse analysis of the controversy about suspending the private standard for organic farming adopted by the ...

  8. StreamNet, 1999-2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Bruce; Roger, Phil; Butterfield, Bart (Pacific States Marine Fisheries Commission, Gladstone, OR)

    2001-09-01

    The StreamNet Project is a cooperative project that provides basic fishery management data in a consistent format across the Columbia Basin region, with some data from outside the region. Specific categories of data are acquired from the multiple data generating agencies in the Columbia Basin, converted into a standardized data exchange format (DEF) and distributed to fish researchers, managers and decision makers directly or through an on-line data retrieval system (www.streamnet.org). The project is funded by the Bonneville Power Administration (BPA) as part of the Northwest Power Planning Council's (NWPPC) Fish and Wildlife Program. This cooperative effort is composed of a region-wide project administered by the Pacific States Marine Fisheries Commission (PSMFC) that is responsible for project management, regional data management and data delivery (Region), plus seven contributing projects within the data generating entities: Columbia River Intertribal Fish Commission (CRITFC); Idaho Department of Fish and Game (IDFG); Montana Fish, Wildlife and Parks (MFWP); Oregon Department of Fish and Wildlife (ODFW); Shoshone-Bannock Tribes; U. S. Fish and Wildlife Service (FWS); and Washington Department of Fish and Wildlife (WDFW). The contributing projects are funded through the StreamNet contract but work within their respective agencies and are referred to here as the agency's StreamNet project (for example, ''IDFG StreamNet'' for Idaho's project). The StreamNet Project provides an important link in the chain of data flow in the Columbia Basin, with specific emphasis on data collected routinely over time by management agencies. Basic fish related data are collected in the field by the various state, tribal and federal agencies in the basin for purposes related to each agency's individual mission and responsibility. As a result, there often is a lack of standardization among agencies in field methodology or data management. To be

  9. Applicability of Perinereis aibuhitensis Grube for fish waste removal from fish cages in Sanggou Bay, P. R. China

    Science.gov (United States)

    Fang, Jinghui; Jiang, Zengjie; Jansen, Henrice M.; Hu, Fawen; Fang, Jianguang; Liu, Yi; Gao, Yaping; Du, Meirong

    2017-04-01

    The present study investigated the applicability of integrated polychaete-fish culture for fish waste removal to offset negative impact induced by organic benthic enrichment. A field study demonstrated that deposition rate was significantly higher underneath the fish farm than that in control area. The material settling under the farm was characterized by a high amount of fish feces (45%) and uneaten feed (27%). Both feeding rate (FR) and apparent digestibility rate (ADR) increased with decreasing body weight, as was indicated by significantly a higher rate observed for the groups containing smaller individuals in a lab study. The nutrient in fresh deposited material (De) was higher than that in sediments collected under the farm (Se), resulting in lower feces production but higher apparent digestibility rate for the De group as feeding rate was similar. Consequently, higher nutrient removal efficiency was observed in the De group. A mass balance approach indicated that approximately 400-500 individuals m-2 is required for removing all waste materials deposited underneath the fish farm, whereas abundance can be lower (about 300-350 individuals m-2) when only the fish waste needs to be removed. The results showed that a significant amount of waste had been accumulated in the fish cages in Sanggou Bay. The integration of fish with P. aibuhitensis seems promising for preventing organic pollution in the sediment and therefore is an effective strategy for mitigating negative effect of fish farms. Thus such integration can become a new IMTA (integrated multi-trophic aquaculture) model in Sanggou Bay.

  10. Fish allergy and fish allergens

    DEFF Research Database (Denmark)

    Kuehn, A; Hilger, Christiane; Ollert, Markus

    2016-01-01

    but patients with this phenotype constitute an important sub-group among fish-allergic individuals. 2. Newly identified fish allergens, enolases, aldolases, and fish gelatin, are of high relevance as the majority of the fish-allergic individuals seem to develop specific IgE against these proteins. The present......Fish is one of the main elicitors for food allergies. For a long time, the clinical picture of fish allergy was reduced to the following features. First, fish-allergic patients suffer from a high IgE cross-reactivity among fishes so that they have to avoid all species. Second, clinically relevant...... symptoms are linked to the presence of IgE-antibodies recognizing parvalbumin, the fish panallergen. This view was challenged by results from recent studies as follows. 1. Allergic reactions which are limited to single or several fish species (mono-or oligosensitisations) apply not only to single cases...

  11. Efficiency comparisons of fish sampling gears for a lentic ecosystem health assessments in Korea

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Han

    2016-12-01

    Full Text Available The key objective of this study was to analyze the sampling efficiency of various fish sampling gears for a lentic ecosystem health assessment. A fish survey for the lentic ecosystem health assessment model was sampled twice from 30 reservoirs during 2008–2012. During the study, fishes of 81 species comprising 53,792 individuals were sampled from 30 reservoirs. A comparison of sampling gears showed that casting nets were the best sampling gear with high species richness (69 species, whereas minnow traps were the worst gear with low richness (16 species. Fish sampling efficiency, based on the number of individual catch per unit effort, was best in fyke nets (28,028 individuals and worst in minnow traps (352 individuals. When we compared trammel nets and kick nets versus fyke nets and casting nets, the former were useful in terms of the number of fish individuals but not in terms of the number of fish species.

  12. Environmental impacts of coastal farming: carbon and nitrogen budgets for trout farming activity in Kaldbaksfjørđur (Faroe Islands)

    DEFF Research Database (Denmark)

    Nordi, Gunnvør a; Glud, Ronnie N.; Gaard, Eilif

    2011-01-01

    Flow of organic carbon (OC) and nitrogen through a sea cage trout farm was calculated on the basis of detailed studies of the farming operation, water circulation, OC and nutrient transport and recycling processes in sediment. A third of the OC and nitrogen provided by fish food was incorporated...... into fish biomass, which is more than has been found in previous studies. Most OC input was respired by the fish (52 to 70%), and ~63% of the associated nitrogen was lost as dissolved inorganic nitrogen (DIN), potentially stimulating pelagic primary production. Approx. 6% of carbon and 5% of nitrogen...... derived from fish food settled on the seabed, where it was either mineralized or accumulated in the sediment. Based on transect measurements of diagenetic activity, the farm footprint was found to cover an area ~10 times the farm area. OC mineralization in the sediment increased linearly with increasing...

  13. Quantitative trait loci for resistance to fish pasteurellosis in gilthead sea bream (Sparus aurata)

    NARCIS (Netherlands)

    Massault, C.; Franch, R.; Haley, C.; Koning, de D.J.; Bovenhuis, H.; Pellizzari, C.; Patarnello, T.; Bargelloni, L.

    2011-01-01

    Fish pasteurellosis is a bacterial disease causing important losses in farmed fish, including gilthead sea bream, a teleost fish of great relevance in marine aquaculture. We report in this study a QTL analysis for resistance to fish pasteurellosis in this species. An experimental population of 500

  14. Petri Nets-Applications

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/004/09/0044-0052. Author Affiliations. Y Narahari ...

  15. Safety nets or straitjackets?

    DEFF Research Database (Denmark)

    Ilsøe, Anna

    2012-01-01

    Does regulation of working hours at national and sector level impose straitjackets, or offer safety nets to employees seeking working time flexibility? This article compares legislation and collective agreements in the metal industries of Denmark, Germany and the USA. The industry has historically...

  16. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  17. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  18. Game Theory .net.

    Science.gov (United States)

    Shor, Mikhael

    2003-01-01

    States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…

  19. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism...

  20. Combined ship routing and inventory management in the salmon farming industry

    OpenAIRE

    Agra, Agostinho; Christiansen, Marielle; Ivarsoy, Kristine S.; Solhaug, Ida Elise; Tomasgard, Asgeir

    2017-01-01

    We consider a maritime inventory routing problem for Norway's largest salmon farmer both producing the feed at a production factory and being responsible for fish farms located along the Norwegian coast. The company has bought two new ships to transport the feed from the factory to the fish farms and is responsible for the routing and scheduling of the ships. In addition, the company has to ensure that the feed at the production factory as well as at the fish farms is within the inventory lim...