Price cointegration in spatial markets: An application to milkfish markets in Taiwan

Abstract

The objectives of this study are to analyze the interdependent behavior of lead‐lag milkfish price adjustments between vertically‐related markets (from production to consumption) as well as between five major horizontally‐related wholesale markets. Empirical results show that there is a two‐way lead‐lag cointegrating price relationship between milkfish wholesale and retail markets. Since the fish wholesale market cannot completely and quickly assimilate the retail market information, the speed of response of wholesale prices to retail price changes is relatively slow, inducing low pricing efficiency. The Taipei wholesale market appears to cause the greatest leadership impact on the milkfish price formation compared to other wholesale markets in both the long‐run and short‐run. The results also reveal that there is a high degree of integration relationship between the horizontally integrated wholesale markets (Chiayi, Changhwa and Taichung) for milkfish in the southwestern region within a short distance.     

Optimal harvesting of farmed Atlantic salmon at two cohort management strategies and different harvest operation restrictions

Abstract

The main harvest planning problem in commercial fish farms is to determine the best time‐sequence of harvesting different fish cohorts in order to maximize the overall farm profit. Due to both annual and fish‐size variations in market prices, future forecasts of fish growth and size distribution are required to optimize harvest plans. Two management strategies for harvesting size‐structured fish cohorts are considered. The first strategy allows the fish farmer, at any time, to size‐grade, harvest and sell the most profitable fish sizes from the standing stock. The second strategy allows the fish farmer to harvest and sell a fish batch with similar size distribution as that of the standing stock. In this paper, two size‐structured fish growth models have been built to fit the two management strategies. The growth models are integrated in a multiperiod linear programming model that optimizes the harvest outputs for each of the two management strategies. Model outputs demonstrate clearly that it is more profitable to size‐grade fish prior to harvest compared to harvesting a batch of fish with similar size distribution to that of the standing stock. Five different harvest operations constraints have been identified for commercial salmon farming. The decrease in profitability of fish farming is shown for a variety of harvest operation constraints.     

Testing for market power in the UK salmon retail sector

Abstract

This paper presents an investigation into the structure of the salmon retail market in the UK. Evidence of the potential for market power is analysed using non‐linear three‐stage least squares to estimate a dynamic error correction model (ECM) following Bresnahan (1982) and Lau (1982) theoretical approaches. Results indicate that the system is well represented by the model and that the market is competitive in both the short and long run. This is the first study using this approach for the UK fish market and our conclusions support findings from previous empirical analyses of the food retail market, albeit using a different methodology.     

Behaviour of price transmissions in vertically coordinated markets: The case of frozen black tiger shrimp (Penaeus monodon)*

Abstract

This study analyses the behaviour of the price transmission process for the leading cultured shrimp species, black tiger shrimp (Penaeus monodon), in both forward and backward directions between Thai and Indonesian shrimp packer markets and the Japan Tokyo wholesale market. The bivariate cointegration approach using the Engle‐Granger two‐stage estimation procedure is applied in this study. The results show that Tokyo wholesale prices appear to have stronger backward influences on the formation of overseas contract prices used by Japanese shrimp importers in the Thai and Indonesian shrimp packer markets. In addition, there is a tendency for the speed of price transmissions in the long term to increase with increasing size class (from 26 to 30–21–25 and 16–20 counts per pound) of black tiger shrimp, regardless of estimation specification in the direction of price transmissions and the shrimp country of origin.     

Aquaculture's potential impacts on conservation of wild stocks and biodiversity

Abstract

Anderson theorizes that development of the aquaculture of a fish species (also captured in an open‐access fishery) favours the conservation of its wild stocks, if competitive market conditions prevail. However, his theory is subject to significant limitations. While this is less so within his model, it is particularly so in an extended one outlined here. These other models allow for the possibility that aquaculture development can impact negatively on wild stocks thereby shifting the supply curve of the capture fishery, or raise the demand for the fish species subject both to aquaculture and capture. Such development can threaten wild fish stocks and their biodiversity. While aquaculture development could in principle have no impact on the biodiversity of wild stocks or even raise aquatic biodiversity overall, its impact in the long‐term probably will be one of reducing aquatic diversity both in the wild and overall. The development of aquaculture does not automatically ensure long‐term sustainability of fish and other aquatic supplies.     

Developing a new tool based on a quantile regression mixed‐TGC model for optimizing gilthead sea bream (Sparus aurata L) farm management

In this work, a seasonal quantile regression growth model for the gilthead sea bream (Sparus aurata L) based on an aggregation of the quantile TGC models with exponent 1/3 and 2/3, named the “Quantile TGC‐Mixed Model”, is presented. This model generalizes the proposal of Mayer, Estruch and Jover (Aquaculture, 358‐359, 2012, 6) in the sense that the new model is able to describe the evolution of weight distribution throughout an entire production cycle, which could be a powerful tool for fish farm management. The information provided by the model simulations enables us to estimate total fish production and final fish size distribution and helps to design and simulate production and sales plan strategies considering the market price of different fish sizes, in order to increase economic profits. The most interesting alternative in the studied case results in sending all production when 0.25 quantile fish reach 600 g, although on each fish farm it would be necessary to evaluate optimum strategy depending on its own quantile regression model, the production cost and the market price.     

Modelling the oceanic habitats of two pelagic species using recreational fisheries data

Defining the oceanic habitats of migratory marine species is important for both single species and ecosystem‐based fisheries management, particularly when the distribution of these habitats vary temporally. This can be achieved using species distribution models that include physical environmental predictors. In the present study, species distribution models that describe the seasonal habitats of two pelagic fish (dolphinfish, Coryphaena hippurus and yellowtail kingfish, Seriola lalandi), are developed using 19 yr of presence‐only data from a recreational angler‐based catch‐and‐release fishing programme. A Poisson point process model within a generalized additive modelling framework was used to determine the species distributions off the east coast of Australia as a function of several oceanographic covariates. This modelling framework uses presence‐only data to determine the intensity of fish (fish km^?2), rather than a probability of fish presence. Sea surface temperature (SST), sea level anomaly, SST frontal index and eddy kinetic energy were significant environmental predictors for both dolphinfish and kingfish distributions. Models for both species indicate a greater fish intensity off the east Australian coast during summer and autumn in response to the regional oceanography, namely shelf incursions by the East Australian Current. This study provides a framework for using presence‐only recreational fisheries data to create species distribution models that can contribute to the future dynamic spatial management of pelagic fisheries.     

New organizational forms within the aquaculture industry: The fish‐farming enterprise as a ‘virtual’ organization

Abstract

The international aquaculture industry is characterized by a global integration process with increasing competition across borders and continents. The rapid development of technology, the extended market rivalry due to new firm entries, and the elevation of quality standards in the international seafood market place a heavy strain on the strategy development process of aquaculture enterprises. In this article, we focus on the ties between strategic positioning in the market and the organizational configuration of the firm. The virtual organization is introduced as an organizational form for a dynamic fish‐farming enterprise. A virtual organization is characterized by flexible borders, emphasis on external cooperative relations and networks instead of ownership integration, and norm‐based relational contracts as focal governance mechanism. The results from an in‐depth, longitudinal study of a Norwegian fish farming enterprise are presented.     

Adoption of management and technological practices by fishpond operators in Nepal

Abstract

This study examines adoption of major management and technological practices by fishpond operators in Nepal. A socio‐economic survey was conducted in 1994 covering 358 fishpond operators in eight of the 21 aquaculture production districts of Nepal. Factor and multiple regression models were employed in data analysis. The results indicate that 30 adoption practices can be summarized by six indices. The study suggests that the education level of fishpond operators plays an important role in increased adoption of management and technological practices. Ethnicity, geographical location, smaller fish farm size, access to inputs and cash reserves and proximity to market infrastructure also increase the probability of adoption of desirable management and technological practices.     

Production and application of on‐grown Artemia in freshwater ornamental fish farm

Abstract

This paper describes a pilot culture system for the production of on‐grown Artemia in freshwater ornamental fish farms. The system had 21 culture units, each consisting essentially of three components: an oval‐shaped raceway, an air‐water lift system and two waste collectors. Using artificial seawater at 20 ppt for culture and at a mean production rate of 3 kg/m³ of water in a 12‐day cycle, the system had a production capacity of 8 metric tons of on‐grown Artemia a year. Biochemical analyses were preformed to evaluate the nutritional value of the on‐grown Artemia against three conventional live feeds, viz. live Artemia nauplii, live Moina and frozen bloodworms. Cost‐benefit analysis showed that with a capital investment of US$ 82,000 and an annual cost of production of US$ 81,000, the system achieved a high internal rate of return of 88% over a 10‐year period and a short payback period of 1.23 years. The availability of on‐grown Artemia would not only offer farmers and exporters a better alternative live food organism for feeding to their fish, but more importantly the possibility of enhancing the fish performance and quality through bioencapsulation.     

Price interactions between salmon and wild caught fish species on the Spanish market

Abstract

The introduction and rapid expansion of farmed salmon production in the mid 1980s has transformed the international market for salmon. Spain is one of the most important markets for fish within Europe and the world, and has seen a substantial increase in its demand for salmon. As in other European countries, this has raised concerns that the increased supply of salmon to Spain may have detrimental effects on the market prices of traditional (wild‐caught) species.

In this paper, the extent to which salmon competes with the main traditional fish species in the Spanish market is examined using market delineation methodologies. In particular, the potential interactions between species is examined in a multivariate cointegration framework. The results suggest that salmon is at best only a weak substitute for tuna, hake and whiting, but no significant interaction could be found.     

Economic analysis of overwinter feeding regimens for channel catfish (Ictalurus punctatus)

Abstract

Overwintering is a major source of uncertainty for US catfish farmers, particularly decisions on feeding. To address this issue, economic analysis was undertaken using results from pond experiments. Three overwintering strategies (full‐feed, partial‐feed, and no‐feed) for two year classes of catfish were compared. Year 1 fin‐gerlings were 22 g and year 2 fish were 420 g at stocking. Winter feeding was based on temperature and body weight percentages; (1) full‐feeding followed the regime during the November to April period; (2) partial‐fed treatments followed the temperature/body weight regimen only during the months of November, March and April, with no feeding during the coldest months of December to February; and (3) no‐feeding treatments received no feed during the overwinter period. Cost and returns were estimated for each alternative and each alternative was assessed using: (1) overwinter period experimental results, (2) overwinter period experimental results extended through the grow‐out period, (3) overwinter period experimental results extended to minimally acceptable fish sizes, and (4) adjusted estimates to reflect commercial‐scale practices. Sensitivity analyses on feed conversion ratios, stocking rates and fish selling prices were also conducted on commercial‐scale enterprises. Results consistently showed partial‐fed overwinter practices to be most profitable. Secondly, year 1 fish always had higher returns than year 2 fish due largely to the additional overwintering period and associated variable and fixed costs incurred by the year 2 fish production practices. The data upon which this analysis was based do not include the possibility of having a harvest‐sized fish going into the winter period.     

Justification for genetic improvement in growth rates of black bream (Acanthopagrus butcheri): A partial budgeting analysis

Abstract

Black bream (Acanthopagrus butcheri) appear an ideal candidate for the developing saline aquaculture industry of inland Western Australia. However, current maximum growth rates of 150g/annum are too slow for profitable production. This study investigated whether enhanced growth rates of black bream would improve profitability and justify a genetic improvement program. A partial budget analysis was conducted for two different fish production systems; a commercial operation that incurred more operating expenses due to costs associated with farm initiation (stand‐alone farm model), and an existing farm that diversified into aquaculture using the saline water resources of established farm dams (integrated farm model). Sensitivity analyses indicated that a 33 per cent increase in growth rate to at least 200g/annum would allow either production system to return a profit at a farm‐gate price of AUS$6/kg whole fish, with fish survival rates of 98 per cent for the stand‐alone farm, and 65 per cent for the integrated farm model. These results are discussed in the context of the genetic and economic consequences of selection for improved growth rates, and for developing breeding objectives and a genetic improvement program for black bream.     

Optimal harvesting strategies: Practice versus theory

Abstract

Over the last decade or so, a number of bioeconomic models have been developed with the expressed objective of identifying the optimal time to harvest farmed fish. The models explicitly incorporate growth rates, prices and costs, but have generally excluded risk except implicitly through the discount rate. Implicit in this is the assumption that risk is continuous, such that the probability of significant changes in key parameters (e.g. prices, mortality rates etc) is independent of time. In reality, these factors can vary over time. In this paper, the optimal harvesting strategies for two farmed species were analysed using a bioeconomic model. The model was based on previous models applied in the literature, with a new feed‐use component applied. The theoretical ‘optimal’ harvest strategy was compared with actual behaviour, and the factors that may affect divergences in the results examined.     

Alternative routes to piscivory: Contrasting growth trajectories in brown trout (Salmo trutta) ecotypes exhibiting contrasting life history strategies

Large and long‐lived piscivorous brown trout, Salmo trutta, colloquially known as ferox trout, have been described from a number of oligotrophic lakes in Britain and Ireland. The “ferox” life history strategy is associated with accelerated growth following an ontogenetic switch to piscivory and extended longevity (up to 23 years in the UK). Thus, ferox trout often reach much larger sizes and older ages than sympatric lacustrine invertebrate‐feeding trout. Conventional models suggest that S. trutta adopting this life history strategy grow slowly before a size threshold is reached, after which, this gape‐limited predator undergoes a diet switch to a highly nutritional prey source (fish) resulting in a measurable growth acceleration. This conventional model of ferox trout growth was tested by comparing growth trajectories and age structures of ferox trout and sympatric invertebrate‐feeding trout in multiple lake systems in Scotland. In two of the three lakes examined, fish displaying alternative life history strategies, but living in sympatry, exhibited distinctly different growth trajectories. In the third lake, a similar pattern of growth was observed between trophic groups. Piscivorous trout were significantly older than sympatric invertebrate‐feeding trout at all sites, but ultimate body size was greater in only two of three sites. This study demonstrates that there are multiple ontogenetic growth pathways to achieving piscivory in S. trutta and that the adoption of a piscivorous diet may be a factor contributing to the extension of lifespan.     

Evaluation of zebrafish (Danio rerio) as an animal model for the viral infections of fish

Zebrafish (Danio rerio) is a laboratory model organism used in different areas of biological research including studies of immune response and host–pathogen interactions. Thanks to many biological tools available, zebrafish becomes also an important model in aquaculture research since several fish viral infection models have been developed for zebrafish. Here, we have evaluated the possible use of zebrafish to study infections with fish viruses that have not yet been tested on this model organism. In vitro studies demonstrated that chum salmon reovirus (CSV; aquareovirus A) and two alloherpesviruses cyprinid herpesvirus 1 (CyHV‐1) and cyprinid herpesvirus 3 (CyHV‐3) are able to replicate in zebrafish cell lines ZF4 and SJD.1. Moreover, CSV induced a clear cytopathic effect and up‐regulated the expression of antiviral genes vig‐1 and mxa in both cell lines. In vivo studies demonstrated that both CSV and CyHV‐3 induce up‐regulation of vig‐1 and mxa expression in kidney and spleen of adult zebrafish after infection by i.p. injection but not in larvae after infection by immersion. CyHV‐3 is eliminated quickly from fish; therefore, virus clearing process could be evaluated, and in CSV‐infected fish, a prolonged confrontation of the host with the pathogen could be studied.     

DISAGGREGATED ANALYSIS OF FISH SUPPLY,DEMAND, AND TRADE IN ASIA: BASELINE MODEL AND ESTIMATION STRATEGY

ABSTRACT

Quantitative modeling of fish supply, demand and trade is a useful tool for analyzing recent structural changes, such as the rapid development of aquaculture. Existing models are, however, limited by their use of highly aggregated fish categories and assumed (rather than estimated) elasticities. This paper outlines an estimation strategy and a multiproduct equilibrium model for disaggregated analysis of fish supply, demand, and trade. The model is composed of a producer, consumer and trade core, and is specified to accommodate special features of the fish sector. The estimation and modeling strategy also address common data problems, such as heterogeneity of fish types, diversity of production categories, and so forth. The model has been applied to nine major fish producers in developing Asia.     

Using PET/CT imaging to characterize 18 F‐fluorodeoxyglucose utilization in fish

Fish are becoming an increasingly important research species as investigators seek alternatives to mammalian models. Combined positron emission tomography/computed tomography with ¹⁸ F‐fluorodeoxyglucose (FDG‐PET/CT) is a powerful new technology that has been extensively applied for high‐resolution imaging in mammals but not fish. CT scanning provides detailed anatomical three‐dimensional imaging. PET scanning detects areas of cellular activity using radio‐labelled molecular probes with specific uptake rates appropriate to the tissue involved. FDG‐PET is used in oncology because tissues with high glucose uptake, such as neoplasms, are intensely radio‐labelled. PET/CT combines the two technologies, so that images acquired from both devices are merged into one superimposed image, thus more precisely correlating metabolic activity with anatomical three‐dimensional imaging. Our objective was to determine if fish can be viable replacement animals in cancer studies using this technique by analysing the similarities between fish and humans in glucose uptake in select organs across multiple fish species. Rapid, quantifiable glucose uptake was demonstrated, particularly in brain, kidneys and liver in all imaged fish species. Standard uptake values for glucose uptake in the major organ systems of fish were more similar to those of humans than mice or dogs, indicating that fish may serve as effective alternative animal models using this technology. Applications for this technique in fish may include oncogenesis and metabolism studies as well as screening for environmental carcinogenesis.     

A comparison of one‐slope straight broken‐line,two‐slope straight broken‐line,quadratic broken‐line and quadratic models to estimate an accurate optimum feeding rate for juvenile olive flounder (Paralichthys olivaceus)

Two feeding trials using different commercial feeds and different fish sizes were conducted to compare model performance of various regression models on the estimation of optimum feeding rates (OFR; % BW/day) for juvenile olive flounder. Six feeding rates ranging from 1% to 11% in trial I and another six feeding rates ranging from 1% to 6% in trial II were tested. Final body weight, weight gain, feed conversion ratio, condition factor, nutrient gains, and whole‐body lipid and energy contents were significantly influenced by the feeding rates in both trials. The overall responses shown in trial I were generally comparable to those observed in trial II. In trial I, the OFR was estimated to be 7.3%, 5.7%, 9.8% and 10.2% by the one‐slope straight broken‐line, two‐slope straight broken‐line, quadratic broken‐line and quadratic models, respectively. In trial II, the OFR was estimated to be 4.8%, 4.6%, 8% and 8% by the one‐slope broken‐line, two‐slope broken‐line, quadratic broken‐line and quadratic models, respectively. Based on the model selection criteria (R²_adj and AICc), the quadratic broken‐line model was selected as the best‐fit model in both trials. This model that describes the dose–response relationship best among the tested models can be recommended when determining an OFR.     

Mortality in juvenile salmonids passed through an agricultural Hidrostal pump

Abstract Hidrostal pumps have been successfully employed in live fish transport, yet their effectiveness in fish passage is incompletely understood. This study investigates juvenile salmonid mortality in experimental passage trials through Hidrostal pumps at an agricultural pump facility in Washington State, USA. The effects of impeller pitch, rotational speed and fish body size on passage survival were examined. Hatchery‐reared salmonids [Oncorhynchus mykiss (Walbaum) and Oncorhynchus kisutch (Walbaum)] were introduced to low‐ and high‐pitch impeller assemblies operating at two speeds. Instantaneous mortality rates ranged from 0 to 4% for high‐pitch trials and from 3 to 10% for low‐pitch trials. Larger fish experienced sublethal injury at higher rates (approximately 60% injured) than smaller fish (approximately 23% injured) and exhibited greater susceptibility to injury at higher pump speed. Injury between trials was compared by ranking according to severity and summed for each treatment; greater injury severity was found for the low‐pitch impeller and from higher rotational speeds. Although injury and mortality rates to fish passing through Hidrostal pumps may be reduced through the use of higher‐pitch impellers and lower operational speeds, the use of pump‐bypass facilities may be warranted where acceptable impact thresholds are low.