Fish Farming Production Research Articles

Evidence of multiple species of Chilodonella (Protozoa, Ciliophora) infecting Australian farmed freshwater fishes

Parasitic Chilodonella species, Chilodonella piscicola and Chilodonella hexasticha, cause considerable economic losses globally to freshwater farmed fish production. Some genetic studies of Chilodonella spp. have indicated that many species within the genus may form cryptic species complexes. To understand the diversity of Chilodonella spp. infecting Australian freshwater farmed fish, specimens were isolated from infected barramundi (Lates calcarifer) and Murray cod (Maccullochella peelii) from fish farms in tropical north Queensland (QLD), temperate Victoria (Vic) and New South Wales (NSW) for genetic and morphological analysis. Parasites were stained and measured for morphological description and comparative phylogenetic analyses were performed using the mitochondrial small subunit (mtSSU) rDNA marker. Morphological analyses revealed four distinct morphotypes of Chilodonella infecting farmed barramundi and Murray Cod. Three putative species were isolated from barramundi (Chilodonella hexasticha, C. acuta and C. uncinata) and one from Murray cod (C. piscicola). However, phylogenetic analyses detected only three distinct genotypes, with the putative C. hexasticha and C. piscicola sharing 100% sequence identity. This suggests that Australian isolates of C. hexasticha and C. piscicola could represent the same species and may exhibit phenotypic plasticity. Further molecular analysis, including isolates from the type localities, should be performed to support or refute the synonymy of these species.

The flagellar master operon flhDC is a pleiotropic regulator involved in motility and virulence of the fish pathogen Yersinia ruckeri.

To investigate the function of the master flagellar operon flhDC in the fish pathogen Yersinia ruckeri and compare the effect of a constructed flhD mutation to a naturally occurring fliR mutation causing loss-of-motility in emergent biotype 2 (BT2) strains. Yersinia ruckeri flhD and fliR mutants were constructed in a motile strain. Both mutations caused loss-of-motility, ablation of flagellin synthesis and phospholipase secretion, similar to naturally occurring BT2 strains. Transcriptome analysis confirmed flhDC regulation of flagellar, chemotaxis and phospholipase loci as well as other genes of diverse function. The flhD mutation confers a competitive advantage within the fish host when compared with its parent strain, while this advantage was not seen with the naturally occurring fliR mutation. An intact flhD is necessary for expression of the flagellar secretion system as well as other diverse loci, consistent with a role for flhD as a pleiotropic regulator. The maintenance of the flhD locus in Y. ruckeri strains suggests its importance for aspects of Y. ruckeri biology other than virulence, since the flhD mutation conferred a competitive advantage during experimental challenge of rainbow trout. Yersinia ruckeri is the causative agent of enteric red mouth disease, an invasive septicaemia that affects farmed salmonid fish species. Disease outbreaks can cause severe economic losses in aquaculture. BT2 variants, which have independently emerged worldwide, are an increasing threat to farmed fish production. Knowledge of mechanisms involved in virulence, conserved functions and gene regulation among strains may be exploited for the development of novel disease control strategies to prevent pathogen growth or virulence phenotypes within aquaculture.

Boom and bust in Andhra Pradesh: Development and transformation in India's domestic aquaculture value chain

India is the world's second largest producer of farmed fish, and the state of Andhra Pradesh (AP) is by far the most important producer of farmed fish in India. Freshwater aquaculture has boomed in AP since the late 1970s, first with carps, then pangasius catfish. Over this period fish pond area and farmed fish production grew from nothing to reach 142,000 ha and 1.5 million tons, respectively. Despite its scale and dramatic consequences, the boom has received little attention in the international literature. The present paper addresses this gap by analyzing changes in the structure and conduct of each segment of AP's freshwater aquaculture value chain during four distinct phases of development (incubation, take-off, maturation and modernization). This analysis reveals that aquaculture development in AP shares many characteristics with agricultural commodity booms elsewhere in Asia. The paper contributes to the literature on crop booms by: 1) characterizing Southern domestic demand for agricultural products as an important but overlooked driver of agrarian development, and; 2) identifying interlinked processes of innovation and transformation in off-farm segments of the supply chain as a central feature of crop booms.

Consumer perceptions of farmed fish

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, domain-specific innovativeness, subjective knowledge, suspicion of novelties and optimistic bias) are tested as segmentation basis with the objective of defining a number of cross-border consumer segments with distinctive and clear-cut profiles in terms of consumer perceptions towards farmed fish. Findings Based on the consumer psychographic profiles, three distinct segments are found: involved traditional, involved innovators and ambiguous indifferent, of which the first two constitute especially interesting targets for market positioning strategies for aquaculture products. Practical implications The results of the segmentation analysis opens new horizons in terms of positioning and differentiation of fish products from the aquaculture industry according to the most important potential market segments. Originality/value The current research brings insights into different pan-European consumer segments and their characteristics that allow for a corresponding differentiation strategy within the aquaculture industry. The fact that the segments tend to be uniform across all countries suggests a relatively homogeneous or converging European fish-related culture.

Increasing fish farm profitability through aquaculture best management practice training in Egypt

Egyptian aquaculture production has grown rapidly to over one million tons per year so that it now provides most of the country's fish supply. However, Egyptian fish farmers have received little extension advice or training. An intervention starting in 2012 aimed to address this gap by providing best management practice (BMP) training for pondbased tilapia monoculture and tilapia-mullet polyculture fish farmers. A series of field-based training modules were developed and designed with the participation of leading fish farmers and delivered through private sector farmer-trainers to over 2400 fish farm owners and managers. This paper reports on the results of an impact assessment survey carried out in 2015 comparing fish farm performance, production and profitability in randomly selected farms where the manager had received and was applying the principles of BMP training (BMP) and farms where the manager had not received IEIDEAS project training (control). The results show that although the two groups were very similar in terms of general farm characteristics, BMP farms were more likely to practice tilapia-mullet polyculture than monoculture of tilapia. The main BMP training messages apparent in the results were improved feed and fertilizer management. This resulted in more efficient food conversion ratios in BMP farms compared to control farms. Average fish yields and values were similar between the two groups, although BMP farms produced less small-sized tilapia and more mullet than the control farms. Lower feed costs resulted in significantly lower operating costs in BMP farms compared to control farms, whereas fixed costs were similar for the two groups. Average net profits were significantly higher in BMP farms compared to control farms equivalent to additional profits of over $15,000 for an average farm size of 7.5 hectares. Taking into account the number of farmers trained and BMP adoption rates suggests that $18.9 million additional profits were generated through the intervention in 2014. The results demonstrate that fish farms in mature aquaculture systems can benefit significantly from the adoption of improved farm management practices suggesting that similar approaches, including field-based BMP training and the use of private sector farmer-trainers should be used to accelerate the development of nascent aquaculture sectors in other parts of Africa. Statement of relevanceWhile it is often assumed that training will benefit fish farmers the true economic benefits have rarely been documented. This research demonstrates clear improvements in the profitability of Egyptian fish farmers following best management practice training.

Health and ecological implications of fish consumption: A deeper insight

Many studies suggest that fish consumption could be protective for health, but epidemiological studies on different dietary patterns show that fish-eaters have a higher cardiometabolic risk when compared to people relying on a plant-based diet not including fish. The benefit of fish consumption was related to its content of omega-3 long chain polyunsaturated fatty acids (LC-PUFAs), but toxic chemicals released into environment like heavy metals and several industrial by-products, because of their lipophilic properties, concentrate in fish fatty tissues, the same containing LC-PUFAs. Furthermore, the continuous increase in demand for fish is progressively damaging the marine biodiversity, and the volume of the fishing catch, the latter lower than the demand, made it necessary to resort to fish farming. Although meat, dairy and fish products represent dietary sources of PCBs, the latter represent the main source in human diet (respectively 9%, 19% and 67%). Methyl-mercury's main source also seems to be fish products. Fish farming products are safer for methyl-mercury residue but other substances could be found in higher concentrations than fish caught. Moreover, ecological impact could be detrimental. From this point of view, a reassessment of the health risk-benefit ratio and sustainability of fish consumption is warranted.

Aquaculture in Egypt: status, constraints and potentials

Aquaculture is a globally important industry that provides essential food to a growing world population, with a major role in the supply of cheap animal protein. Very rapid developments have been occurred in aquaculture sector of Egypt in recent years and exhibited the strongest growth of any fisheries-related activity in the country. As a result, aquaculture is considered as the only viable option for reducing the current gap between production and consumption of fish in Egypt. The rapid expansion in support activities such as local feed mills and hatcheries made the sector more sophisticated and diverse. Globally, Egypt ranks 9th in fish farming production and 1st among African countries. The aquaculture is practiced in different production systems including semi-intensive, intensive culture in ponds, tanks, intensive production in cages and traditional extensive production systems, but has yet to be adequately documented. Despite the fact that the aquaculture sector in Egypt has witnessed a spectacular development, it has also created challenges with respect to environmental issues and sustainability. This review provides an overview of the status and the perspectives of Egyptian aquaculture sector.

Comparative life cycle assessment (LCA) of Tilapia in two production systems: semi-intensive and intensive

In order to meet the upscaling demand of food products worldwide, the aquaculture industry has been expanding within the last few years in developed countries. Major expansions of aquaculture farming occurred in many developed countries such as Bangladesh, Indonesia, and Egypt. Egypt ranks ninth in fish farming production worldwide and first on Africa. Egypt has the largest aquaculture industry in Africa which represents two-thirds of African aquaculture production. Tilapia production accounts for 75.5 % of aquaculture production in Egypt. Tilapia aquaculture production has grown exponentially in recent decades until it reached 4.5 million tonnes in 2012 placing Egypt as the second worldwide producer of tilapia after China. The production of tilapia is practiced in different production systems including intensive and semi-intensive systems. These production systems require different resources and impact differently on the environment. The aim of the current study was to model the environmental performance of tilapia production and compare semi-intensive and intensive production systems. The main questions were the following: What are the different impacts of tilapia production on the environment? Which production system is more environmentally friendly? What are the preferable practices for better environmental performance and sustainable ecofriendly industry of Tilapia production? Life cycle assessment (LCA) was employed to determine the environmental impacts of tilapia production and compare semi-intensive and intensive production systems. Data for life cycle inventory were collected from two case study farms for tilapia production in Egypt. Four impact categories were taken into consideration: Global Warming Potential (GWP), Acidification Potential (AP), Eutrophication Potential (EP), and Cumulative Energy Demand (CED). LCA revealed that production of tilapia in intensive farming has less impact on GWP, AP, and CED, while its impact on EP is higher than in semi-intensive farming. The identified impacts from 1-tonne live weight production of tilapia were the following: GWP 960.7 and 6126.1 kg CO2 eq; AP 9.8 and 24.4 kg SO2 eq; EP 14.1 and 6.3 kg PO2 eq; and CED 52.8 GJ and 238.3 GJ eq in intensive and semi-intensive systems, respectively. Fish meal production and energy consumption were the major contributors to different impact indicators in both systems. An overall improvement in environmental performance for tilapia production can be achieved by novel feed formulations that have better environmental performance. Energy consumption is a major area for improvement as well, as proper energy management practices will reduce the overall impact on the environment.

TE INTEGRATION OF WATER HYDRODYNAMICS MODELLING AND REMOTE SENSING DATA TO IMPROVE THE WATER CIRCULATION OF LAKE MANZALA, EGYPT

This paper presents the preliminary results of the application of the ocean model (FVCOM) to replicate the hydrodynamic flows experienced within Lake El-Manzala, Egypt. The construction of this model is used to characterize the ecosystem of this shallow brackish lake and assess a range of sustainable water management strategies. Lake El-Manzala is the largest of the Egyptian shallow coastal lakes on the fringe of the Mediterranean Sea. The lake currently supports 30% of the fresh water fish farm production of Egypt. In recent years the aquatic health of the lake has significantly deteriorated due to an increase in the contamination of the lake by polluted inflows and over intensive aquaculture. The focus of this study is to develop a model that may be employed to investigate the causes, effects and potential solutions to the pollutant loads imposed on the lake. The model has been used to study the hydrodynamic effect that a 40% reduction in the polluted drain water inflows to the lake due to a diversion of this water towards the Sinai for land development. This study concluded that in the western zone of the lake this action slightly changed the magnitude and direction of the water flows and an increase in the salinity levels. Several other lake management scenarios were proposed and the environmental effects on the lake water quality are under investigation. It is concluded that the hydrodynamic models developed may be used to study the cause and effects of other aquatic pollution problems and permit the investigation of potential engineering solutions to improve water quality management.

Iodine enrichment of rainbow trout flesh by dietary supplementation with the red seaweed Gracilaria vermiculophylla

Abstract The effects of different dietary inclusion levels (0, 5 and 10%) of IMTA-cultivated Gracilaria vermiculophylla on rainbow trout growth performance and flesh quality traits were evaluated. Flesh chemical composition (moisture, protein, lipid, vitamin E and iodine contents), sensory attributes and instrumental color were determined after a feeding period of 91 days with the experimental diets. The antioxidant activity of muscle carotenoids and hydrolysates was also determined by the 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. By the end of the experiment, fish fed CTRL or G5 diet reached similar body weight (215–220 g), but fish fed G10 weighed significantly less (167 g). Seaweed inclusion increased flesh moisture and decreased lipid content, with significant differences between the G5 and CTRL groups. Vitamin E content varied among treatments with CTRL fed fish presenting the highest levels of α-tocopherol. Iodine levels in the flesh increased with the seaweed inclusion, with fish fed G5 doubling its iodine content (214.5 μg/kg) in relation to the CTRL (111.7 μg/kg). Instrumental color showed that cooked fillets from fish fed seaweed-rich diets were more luminous (L*), less yellowish (b*) and more reddish (a*) than the CTRL. The sensory evaluation showed that fish fed with seaweed had juicier fillets than the CTRL with G5 presenting the most intense (pinkish) color. The instrumental differences are balanced in such a way that the sensory panel perceived G5 as the sample with higher color intensity. Muscle carotenoid extracts presented no significant antioxidant activity through the ABTS and DPPH assays, whereas muscle hydrolysates showed similar antioxidant activity in all dietary treatments (ca. 33% through DPPH assay). The inclusion of Gracilaria sp. meal in diets for rainbow trout seems to be possible for up to 5%, as higher inclusion levels resulted in significantly smaller fish. The sensory panel perceived G5 as the sample with higher color intensity and juicier than the CTRL. Moreover, flesh iodine content doubled in fish fed G5, confirming seaweed as a natural and effective tool to increase the nutritional value of rainbow trout. Statement of relevance/impact of your paper to the general field of commercial aquaculture This paper is relevant for the aquafeed industry and fish consumers. Fish meal has traditionally been the major dietary protein source for fish, but its reduction in aquafeeds is now a priority goal for the further expansion and sustainability of farmed fish production. Seaweeds may act as nutrient supply in fish, which in turn could ultimately function as vehicle of valuable compounds in human nutrition. This paper shows that 5% Gracilaria sp. meal can be a natural and effective tool to increase the nutritional value of rainbow trout flesh without impacting growth.

English

Bathymetric survey and mapping are important procedures for monitoring temporal changes in hydrogeomorphic characteristics of lakes. This study is the first ever carried out on the lakes, and as such provides relevant baseline information for current use and future studies. The studied lakes (Gwakra, Geriyo, Pariya-Ribadu and Pariya) were purposively selected for the study on the basis of size and relevance. The bathymetric survey was conducted by sounding rod method. Preparation of the Bathymetric Maps involved the application of GIS procedures. Morphometric parameters of the lakes were determined from prepared maps by direct measurements and mathematical computations using appropriate formulae. Information derived from the prepared maps revealed that the lakes are characterized by gentle Basin Slope and almost uniform bottom morphologies with slight ruggedness. Maximum Lengths of the lakes ranged from 0.89 (Pariya) to 3.14 m (Geriyo), while Maximum Widths ranged from 0.34 (Pariya) to 1.52 m (Gwakra). The lakes were also found to be generally shallow with mean dry season depths ranging from 0.40 to 1.33 m and volumes ranging from 0.17 to 1.12 mcm. The lakes were characterized by low Indices of Basin Permanence (0.04 to 0.27), indicating senescence and dominance by littoral plants. Relative depths were also very low (0.07 to 0.42), indicating high propensity of water mixing and circulation of dissolved Oxygen adequate enough to support biological productivity. Thus, the lakes are recommended for substantial fish farming and livestock production in the area.  Proper management involving temporal morphological assessment of the lakes based on this study is also recommended for sustainable use.   Key words: Fluviatile lakes, hydrographic survey, bathymetric mapping, lake morphometric characteristics.

Dinamiche di consumo ed evoluzione degli stili alimentari attraverso l'indagine istat sui consumi delle famiglie

The paper uses the 1973-2009 historical series on domestic food consumption, and analyzes the main changes in the structure of food consumption both at national and regional level. In the first part of the work, it is shown the main changes undergone by domestic food consumption basket relative to the eight main product categories consist of: bread and cereals, dairy products and eggs, meat, fishery and fish farming products, fruit vegetables and potatoes, drinks, coffee sugar and groceries, oils and fats. The evolution of the basket is discussed taking into account the main social and economic factors such as the territorial area, the number of members of the family, type of employment. In the second part of the paper the analysis is developed taking into account the regional data. In this case the objective was to compare the differences in the composition of the basket at the beginning and at the end of the observation period to assess how the specific consumption of the 20 Italian regions have developed. By means of a hierarchical cluster analysis, data from three-year periods 1973-75 and 2007-’09 were compared in an attempt to identify the existence of common evolutionary paths in the composition of spending and lifestyles in food. The analysis at regional level suggests the existence of an evolutionary path generating a a process of convergence of the shares of spending on an unique assortment for all regions. This evidence allows to hypothesize the gradual disappearance of the specific regional life style in foods and the birth of a common and strongly homologated style. Although the type of data used does not allow further consideration to analyze the reasons for this convergence, it seems reasonable to identify the pervasive presence of modern retail and widespread role of the media as the most responsible for this process. Finally it is possible to conclude that the disappearance of regional and specific food habits represent a net loss to the country, at least in terms of culture and.

Adaptation of fish farming production to the environmental characteristics of the receiving marine ecosystems: A proxy to carrying capacity

In order to produce a new regulatory scheme for the fish farming industry in Greece, a Delphi exercise, asking a large number of experts to provide multiplication factors for the production for farms exposing at deeper, offshore and more exposed sites, was used. A simple formula was developed, taking into account the responses of the 31 experts, and three scenarios were derived by using different percentiles for each one of the factors. The system was discussed with a very broad spectrum of stakeholders and was evaluated by an international panel of experts. The results presented here were used as a basis for a ministerial decision which has been the regulatory framework for fish farming in Greece since 2009.

English

A major agricultural sub-sector where achieving food security has become elusive in Nigeria is the fish production subsector. Demand for fish in Nigeria stands at about 1.5 million metric tonnes per annum while domestic production is just 511,700 metric tonnes. The wide gap between demand and supply is attributed to increasing population, improved nutrition, underdeveloped local fish farming potentials and depletion of artisanal sources resulting from unsustainable fishing. The nation spends about N150 billion (US$1billion) annually to bridge the gap between supply and demand. This huge amount spent annually constitutes enormous strain and drain on the nation’s foreign reserves especially when the potentials for local production to meet the domestic market and for export exist in abundance. Consequently, several policy measures have been put in place to stimulate local fish farming. Till date, the results from the colossal investment and policy have not yielded the desired results. Hence, this study attempted to examine the factors determining the sustainability of fish farming in Nigeria with a view to stimulating private investment in the sector, meet national market demand through domestic production and export the excess to enhance the income of farmers. Regression and budgetary analyses were used to analyze data obtained from 100 fish farmers in ten local government areas of Osun State. The result showed that the average net income in the study area was N318,640.75 while the gross margin was N457,327.95. The benefit-cost ratio was 1.5 indicating that for every N100 invested, the enterprise yields additional N50. The regression analysis showed that experience of farmers in fish farming, quantity of feed used, access to credit and size of pond were significant determinants of fish farm production in Nigeria. Major challenges confronting fish farming in the study area are lack of access to credit, high cost of inputs and poor extension services.   Key words: Fish farming, inland waters, nutrition, employment, poverty, sustainable, pond.

Assessment of Environmental Quality of Coastal Fishpond Areas Using Macrobenthic Structure: Multivariate and Graphical Approaches

Environmental degradation that results in decreased quantity of farmed fish production is an issue that often arises in rapid aquaculture industry. This study aims to develop the method of environmental quality assessment of aquaculture using macrobenthic structure to ensure the sustainability of its activity. The research was conducted at three fish farming sites along coastal of Sayung, Demak Regency, Central Java, i.e. milkfish ponds, shrimp ponds, and mixture pond. Determination of the environmental quality of the farms was done by analyzing data and environmental parameters and macrobenthic abundance and biomass using multivariate and the graphical methods. The results of Principle Component Analysis (PCA) projected from an aquatic environment parameters showed no signs of grouping based on three types of ponds, but there are signs of grouping by time sampling, indicating fluctuations in physico-chemical conditions of waters over time. Based on the macrobenthic abundance, study sites were dominated by gastropods (97%), the rest of bivalves (2%) and polychaetes (1%). Results from ordination analysis, ABC curves and k-dominance showed no signs of clustering by types of pond, but between sampling times. This implies that multivariate and graphical methods can sensitively detect any environmental change, particularly changes in macrobenthic community, water quality and sediment over time.

DESIGN AND EVALUATION OF A PNEUMATIC FISH FEED DISTRIBUTOR FOR EGYPTIAN FISH FARMS

A pneumatic fish feed distributor was designed and locally fabricated for Egyptian fish farms to ensure all the fish have equal access to the feed and avoid the manual feeding problems. The performance of the designed pneumatic fish feed distributor was evaluated based on fish pellet degradation, uniformity of fish feed distribution pattern and performance of feeding method. The evaluation was calculated at different operation conditions including different blower air speeds from 10 to 20 m/s, forward speed from 2.62 to 6.39 km/h (from 0.73 to 1.78 m/s, respectively) and feed rates from 10 to 25 kg/min. The obtained results lead to the conclusion that: Using of pneumatic fish feed distributor gave the best results of feed distribution pattern uniformity, eliminated feed breakage wasted as dust and saved about 35%, in fish feeding cost under the optimum operating conditions of air blower speed of 15 m/s, forward speed ranging from 2.53 to 3.42 km/h and feed rate ranging from 20 to 25 kg/min. Using mechanical feeding method (pneumatic fish feed distributor) gained 208.18 ± 24.25 g as an average fish mass with coefficient of variation (C.V) about 11.47% and better feed conversion ratio (FCR) of 1.63 comparing with 183.46 ± 42.73g fish mass with C.V about 23.29% and poor FCR of 1.94 gained by using the hand feeding method at the end of production cycle. Using of pneumatic fish feed distributor is more suitable and acceptable mechanical feeding method to ensure that all the fish have equal access and similar opportunity to the feed which achieving higher uniformity in growth rate and good feed conversion ratio. In addition, it helps avoiding the manual feeding problems of water pollution due to eliminating waste of pellets dissolved in the water and reduces the feeding labor and cost. Consequently, it increases the benefit margins of fish farm production. Therefore, it is recommended to use pneumatic fish feed distributor under the previous optimum operating conditions.

Transferring technology from university to rural industry within a developing economy context: The case for nurturing communities of practice

The primary aim of this paper is to demonstrate how technology transfer between universities and rural industries in developing countries can be achieved effectively, using independent research and advisory centres as intermediaries. It draws on a longitudinal action research study, which experiments with the process of nurturing and bridging communities of practice amongst recipients of technology and stakeholders concerned with technology diffusion, productivity and economic development. Its empirical evidence is from an academic-related, non-government intervention initiative targeting two small-scale industries, namely fish farming and coffee production, in the Cauca region of Colombia. Results demonstrate how barriers to transfer can be overcome. The intervention is considered as instrumental; its key components and outcomes are discussed in detail.

A comparative evaluation of women's perceptions and importance of sustainability in fish consumption

PurposeThe purpose of this paper is to explore women's perceptions about the benefits and risks of fish consumption, while exploring differences on their views about wild and farmed fish, considering light fish consumers.Design/methodology/approachThe methodology adopted is exploratory, using focus group technique, segregating women by education level (higher education versus lower education). A focus group guide was designed, taking into account the following dimensions: attitudes towards fish consumption and perceptions towards farmed fish relative to wild fish, also considering risk perceptions related to farmed versus wild fish.FindingsThis study has shown that fish consumers enjoy the taste of fish and they are strongly convinced that eating fish is healthy. The main reason for their low fish consumption is related to perceive lacking of convenience. Women with higher education levels expressed additional knowledge considering different aquaculture systems and women with lower education levels were convinced that both wild and farmed fish offer benefits and present disadvantages.Originality/valueThe paper shows that attitudes of light fish users are partially similar to heavy fish users considering farmed fish production, with the search for convenience being driven by either perceived lack of time or perceived lack of cookery skills to prepare fish‐based meals.

Analysis of farmed fish movements between catchments identifies a simple compartmentalised management strategy for bacterial kidney disease in Scottish aquaculture

The movement of live fish between fish farms has been identified as a critical risk factor in the spread of disease yet these movements are an essential part of fish farm production cycles. Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a disease which affects farmed salmon and trout production, although the impact on trout is considered less serious than on salmon. It is therefore desirable to minimise the exposure of salmon to R. salmoninarum. The approach presented here shows the potential for the salmon and trout industries to be split into two separately managed compartments in terms of control of spread of BKD by live fish movements. This compartmentalisation system is supported by the low number of cross compartment movements with only six out of 207 active farms in compartment S (mainly salmon) receiving fish from a farm located in compartment T (mainly trout).

Fish Farms at Sea: The Ground Truth from Google Earth

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.