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Crustacean Farming

De
464 pages
Crustacean Farming: Ranching and Culture, Second edition.

John F. Wickins and Daniel O'C Lee.

The second edition of an extremely well-received book, Crustacean Farming, deals with all cultivated crustaceans of commercial significance, shrimp, prawns, crayfish, lobsters, crabs, and spiny lobsters, and examines the criteria by which both the feasibility and desirability of farming proposals are assessed. The characteristics and production methods of farmed and candidate crustacean species are described in sufficient detail to enable areas of profitable involvement to be distinguished form other opportunities presenting only very high risks and possibilities for serious loss. Coverage extends right from broodstock acquisition and management through to the operation of hatcheries, nurseries and on-growing units to key aspects of processing and marketing. New to this second edition are ranching and re-stocking operations together with the culture of ornamental shrimp and small crustaceans used as live food in fish and shellfish hatcheries. The sections on crustacean diseases, genetics and nutrition have been extended in the light of recent research advances.

Examples of investment and operating costs of the different culture options are compared and an analysis of current trends in world crustacean markets is presented to assist in economic and financial appraisal.

Special consideration is given to the place of crustacean farming within the economics of developing nations in relation to social and environmental impact in order to promote awareness of the wider implications of global developments.

The consequences of recent research and technical developments are considered, together with concerns over genetic and animal welfare issues. Specific areas where further advances in technology are needed to improve the reliability or productivity of farming systems are highlighted. This important book is a vital tool and reference work for all those involved with crustacean farming worldwide.

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Chapter 3 Markets
3.1 Overview Crustaceans are among the most highly valued of luxury foods and the high prices they obtain serve to stimulate interest in crustacean farming and to underpin its eco-nomic viability. The potential for aquaculture is all the more apparent because wild fisheries have been unable to react to market demand and their yields have been sta-ble or have increased only gradually. However, although aquaculture production has responded to generally fa-vourable market conditions, many farmers have discov-ered that they cannot take for granted the ability to sell their output at profitable prices. The usual patterns link-ing supply and demand apply in crustacean markets too, and high prices are simply a reflection of limited sup-plies. Some crustacean markets, most notably for frozen shrimp, have undergone structural change and prices fell in the late 1980s as farm output of small and medium sizes increased sharply. In addition, the status of crusta-ceans as luxury foods is a mixed blessing – when econo-mies grow it is reflected in buoyant demand and high prices, but in times of recession, demand and prices can slump disproportionately. Consumers in shrinking econ-omies are more cautious with their disposable income and consumption of luxury foods falls sharply, either directlywhencheaperalternativesareselectedinthesupermarketorindirectlywhenoutingstorestaurantsare minimised. Seafood consumption in Japan, for ex-ample, suffered in the 1990s due to economic setbacks and shrimp consumption dropped to such an extent that in 1997 the USA overtook Japan as the world’s largest importer. ∙ ∙ Shrimp farming now produces around 800 000 mt per year, representing 27% of world shrimp supplies, and an increase of 23% from levels a decade ago (section 1.3). Improved supplies from aquaculture have enabled
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shrimp to compete more effectively in the mass market for everyday foods. For example, in the USA, shrimp is becoming a favourite in casual as well as white-tablecloth restaurants and it has displaced staples such as steak on some menus (Lang 2000). However this trend will slow if shrimp farms continue to suffer production problems related to environmental degradation and dis-ease. Large tonnages ofMacrobrachiumare also being pro-∙ ∙ duced, particularly in China (62 000 mt) and Bangladesh ∙ ∙ (48 000 mt), but while Chinese prawns are consumed on national markets live or fresh on ice, most of the output from Bangladeshi farms enters international trade in the form of frozen tails or frozen whole prawns. Part of the production from other Asian sources such as Thailand and Vietnam is also entering international trade but most prawn sales, as in China, are dependent on local or na-tional markets or on individually targeted export mar-kets where demand has been identified.Macrobrachiumfarmers that do not operate in Bangladesh, China or Vietnam or in similar low-cost production environments have encountered major difficulties in selling their prod-uct at cost-effective prices, particularly in the face of stiff competition with marine shrimp (section 3.3.2). This has restricted the expansion of freshwater prawn farming in many areas of the world despite the fact that this species is widely cultivated. Small producers can often obtain premium prices by supplying nearby restaurants and ho-tels. Success on a larger scale has been limited to coun-tries where freshwater prawns are well established as a desirable food item, for example in Thailand. However, even in this country initial success has been tempered by falling prices resulting from increased farm output. The majority of crayfish farmed in the USA are con-sumed within the same southern states that produce them, with some exports directed at the high price,
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Swedish market. Increasing quantities of crayfish are produced in China and exported to Europe and the USA, although in the latter market trade has been held back by the imposition of penalty duties on Chinese crayfish. Spain is the leading supplier within Europe with much production sold to consumers in France and Sweden as well as home markets. Australian crayfish farmers sell nearly all of their product at home but continue to ex-plore export markets in Europe, the USAand Japan (sec-tion 3.3.3.4). Demand for clawed and spiny lobsters on world mar-kets continues to be very strong. However, any future success with the marketing of farmed lobsters may rely on the successful development of new markets for small animals which, for clawed lobsters at least, are proba-bly the only economically viable size for production by land-based culture systems (sections 3.3.4 and 7.8.9). Farmed crabs are sold live in traditional local markets primarily in Asia. International trade does occur in fro-zen crab products and processed crab meat though this relies almost exclusively on crabs from capture fisheries (section 3.3.5). Although the majority of farmed crustaceans are con-sumed in the USA, Japan and Western Europe, the econ-omies of several developing and newly industrialised countries are strengthening, particularly in Asia, and consumption of luxury crustacean foods in these coun-tries is increasing. South-east Asia, for example, now takes 5% of Indian exports that would traditionally have gone to Europe or Japan (Rao & Prakash 1999). Al-though this trend suffered a reverse during the Asian fi-nancial crisis of 1997–98 it has been notable in countries like Taiwan and Thailand where high-value aquaculture products are increasingly destined for home consump-tion as well as export. The relatively wealthy areas of China such as Beijing and the southern states are also consuming greater quantities of national farm output. Currently shrimp consumption in major shrimp farming nations such as Indonesia and the Philippines is based on small, low-value wild species that are often converted into products such as shrimp paste and shrimp crackers. But as wealthy city dwellers consume more crustaceans, farmed product sells increasingly well within producer countries. Increasing tourism in many developing coun-tries is also serving to boost demand in the hotel and res-taurant trade. Eating habits are among the most deeply rooted ele-ments of a culture and people tend to eat mostly what they have been raised on as children. As a reflection of this, preferences for different types of crustaceans and
different product forms remain very strong within coun-tries or regions (Hottlet 1992). In fact, observers note that there has been an overall trend towards increasing segmentation within crustacean markets and that one of the best strategies for farmers and processors is to make customised products that target individual market segments. Through product diversification and develop-ment an increasing variety of value-added crustacean foods are already being produced, with many finding ready acceptance with consumers (Traesupapet al. 1999). Some products are able to offer greater conven-ience and ease of preparation to the supermarket shop-per, while others such as soft-shell crustaceans begin to open up novel markets (sections 3.3.3.2 and 3.3.5). In all, they hold out considerable hope for generating in-creased overall sales volumes and enhanced revenues. In their analysis of aquaculture markets and market re-search, Kinnucan and Wessels (1997) see the industry following the pattern currently under way in American agriculture with tighter linkages between farm produc-tion and consumer demand, and increased control of the vertical food system by large agribusiness entities. Such entities are well equipped to undertake the necessary market development (section 3.2.5). Another important trend has been the shift of value-added processing activity away from importing coun-tries and towards developing countries where the raw materials originate. Countries like India have started moving into value-added processing rather than remain-ing as suppliers of raw product for overseas processors (Rao & Prakash 1999). This makes good economic sense and is a welcome development. It has been held back by worries about poor quality control and hygiene stand-ards and by a lack of market knowledge. In addition, the EU has obstructed progress by imposing high tariffs on value-added products to protect its labour-intensive fish processing industry (Josupeit & de Franssu 1992). International trade in fresh and frozen shrimp is val-ued at $8.5–9bn per year (Ferdouse 1999) and frozen shrimp is now a commodity like coffee and orange juice with futures contracts and options (see Glossary) traded on the Minneapolis Grain Exchange (section 3.3.1). Aquaculture has been instrumental in this development because farm output has helped to provide the year-round supply of an homogeneous product that provides the basis for a viable futures contract. Aquaculture pro-duction has also reduced the need for large cold-storage holdings. In the USA over the period 1979–86, a more consistent supply of shrimp due to farming enabled aver-age cold-storage holdings to be reduced from two to one
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month’s supply. Nowadays when cold-storage holdings of shrimp build up to high levels, this is a sign of over-supply rather than insecurity about the availability of the product. In the late 1980s inventories climbed to record levels in Japan as buyers stockpiled shrimp awaiting im-provements in prices. Despite an overall improved price stability for shrimp, up-to-date marketing information can be very useful to producers and buyers alike. Regu-lar publications with market analyses and forecasts in-clude: InfofishInternational, Kuala Lumpur SeafoodInternational, Quantum Publishing, Croy-don, UK ShrimpMarketReport, LMR Fisheries Research, Del Mar, California Some specialised Internet sources provide further mar-ket information and analysis: AquacultureOutlook http://jan.mannlib.cornell.edu/reports/erssor/ livestock/ldp-aqs/ InfofishTradeNews  http://www.jaring.my/infofish MarketPriceandIndex  http://www.shrimpcom.com MarketReport, Online Seafood Business  http://www.seafoodbusiness.com/market.html ShrimpNotes  http://www.shrimpcom.com Urner Barry Publications Inc  http://www.seafoodnet.com ShrimpMarketReports  http://www.fis.com
Avault (2000a) provides a useful guide to the terminol-ogy of international seafood trade. If the crustacean farming industry is to market its out-put successfully in the future, not only must it produce competitively priced products, it must also satisfy con-sumer concerns about product safety and product qual-ity. In addition it must acknowledge that many con-sumers are seeking more detailed information about the origins and production methods of their food. Most safe-ty and quality concerns can be effectively addressed through implementation of the management tool known as Hazard Analysis, Critical Control Points (HACCP) and through established measures of quality control and sanitation (sections 3.2.2 and 9.6). But if the label ‘farm-raised’ is to fulfil its true potential as a marketing asset, crustacean farmers will also need to address wider is-
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sues. These include the need to minimise negative en-vironmental impacts and the importance of adherence to industry codes of practice governing the use of anti-biotics (Sze 2000). There are also concerns regarding growth hormones, probiotics, immunostimulants and other additives. At the moment there is little market in-terest in genetically manipulated products because of negative consumer perceptions and the need to demon-strate benefits to the consumer fairly and convincingly. But many consumers respond favourably to products bearing such labels as ‘organic’, so if confusion over the definition of eco-labelling terms can be cleared up (Ducherne 2000; Anon. 2000a) this trend will present further opportunities for responsive producers to satisfy consumer concerns and benefit the environment (Clay 1997). Small steps are already being taken in the right direction: one large shrimp processing operation in Hon-duras, conscious of the need to limit environmental dam-age, chose ammonia as its refrigeration medium rather than freon-based products that have been implicated in the depletion of the ozone layer (Hansen 2000).
3.2 Marketing crustaceans
3.2.1 Importance of correct handling and quality control
In general, crustacean flesh is rich in lipids, protein and free amino acids and has a tendency to perish very quick-ly. The attractive colours of shell and flesh are due to dietary pigments (carotenoids and carotenoproteins) but can be marred by blackening during freezing and thaw-ing (Konosu & Yamaguchi 2000). Thus, in order to en-sure that products reach the consumer in good condition, attention to quality control and careful handling is essen-tial right through all stages of harvesting, processing and marketing. Quality control measures can be begin at the farm even before harvesting commences – for ex-ample, by taking a sample of animals and checking for soft shells and any abnormalities. Soft-shelled shrimp and prawns are liable to break up during harvesting and processing. For all farmed crustaceans the aim is to har-vest when the majority are at mid intermoult stage be-cause at this point the water content and quality of the flesh are optimal. The use of ice is vital when dealing with fresh prod-uct. Ice serves to prevent desiccation, retard bacterial growth, and slow the rate at which flesh will spoil. In spite of this many small-scale traders in developing countries lack knowledge in its proper use. Common
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mistakes are the use of chunks rather than crushed or flaked ice (these forms are softer and have a much better contact area), the addition of ice only to the top of bas-kets of fish and shellfish, and the use of dirty ice which has been in contact with the market floor. Advances in ice-making technology now enable the production of forms of ice with characteristics superior even to those of flaked ice. Flaked ice is thin (1–2 mm), has a low temper-ature (–5°C) and tends to freeze together unless stored in a cooled bunker. Chip ice, in comparison, is thicker (7–8 mm) and has a higher temperature (–0.5°C). It has the advantage of easier storage, in insulated rather than chilled bunkers, and being closer to melting point it steadily moistens the product and has better cooling characteristics (von Rohr 1995). The latest ice technol-ogy, currently being tested with fish, uses a pumpable mixture of ice crystals and water known as slurry or bi-nary ice (Wanget al. 2000). Ice application should begin as soon as possible after harvest to swiftly lower temperatures and maintain them during sorting, grading, weighing and any other process-ing steps prior to cooking or freezing. Figure 3.1 shows a time and temperature profile for shrimp from one inte-grated farm and processing plant in Indonesia. All tem-perature control before freezing is accomplished with chip ice or with a mixture of chip ice and water. As a rough guide, 5 kg of ice are needed for each kg of prod-uct, half to be used at the farm and the remainder during processing. When dealing with live animals careful handling is also critical and can greatly affect market value. Ship-ping and storage facilities provided for exports of live Canadian lobster must result in survival rates above 95% if premium prices are to be obtained. Improvements to acclimation and packing techniques have reduced mor-tality rates among airfreighted spiny lobsters to as low
as 1% (Stevens & Sykes 2000; Sugita & Deguchi 2000). High survival rates for shipments of liveMarsupenaeus japonicusto Japan are also used as an indicator that the whole consignment is likely to be of premium quality (Ovenden 1994). The impact of quality can be readily observed in in-ternational crustacean markets when products fetch dif-ferent prices depending on their country of origin. These differences are based on established reputations for qual-ity rather than the condition of each batch being handled. Thus although China is now building a strong reputa-tion as a supplier of high-quality seafood (Traesupapet al.1999), the average price paid for white shrimp from China has traditionally been lower than that for equiva-lent Ecuadorian product. In Bangladesh the prices paid for shrimp and prawns have been 7–16% lower than the Asian average because of the poor record of some pro-cessors (Cato & Lima dos Santos 1998). In 1997 the EU temporarily banned seafood imports from Bangladesh, India and Madagascar when inspectors found serious deficiencies in hygiene standards (Anon. 1997). Unfor-tunately reputations for quality are rapidly damaged and only slowly repaired. The seizure of a single batch of home-produced shrimp by Australian fisheries inspec-tors in 1990, and subsequent declaration as unfit for human consumption, was potentially damaging to the whole of Australia’s shrimp farming business (Ruello 1990). In Malaysia, problems with maintaining a high-quality image for shrimp exports were at one point at-tributed to a lack of confidence of investors in purchas-ing state-of-the-art processing machinery (Low 1988). Even with the concerted effort of a majority of farmers to raise standards, it is difficult to improve a country’s repu-tation for quality, and action at a national level becomes essential. The Ocean Garden Products Corporation co-ordinates the sale of Mexican seafood on the US market
Fig. 3.1 Profile of shrimp core temperature over time following harvest and individual quick freezing (IQF) in brine at an integrated farm and processing plant. Between harvest and brine freezing, temperature is reduced with chip ice (D. Lee 1999, unpublished data).
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and by enforcing quality control standards it has been able to keep the prices of Mexican shrimp above those of many other exporting countries. There is some scope for the efforts of individual operations to have a posi-tive impact on the marketing of their own products. For example, shrimp sold on Sydney Fish Market from one farm in New South Wales fetched 25% more than shrimp sold the same day from a Queensland farm, the distinc-tion being based on the perceived difference in quality from the two sources (Ruello 1990). Great care is needed to maintain the high-quality, health-food image of crustaceans (Nettleton 1992) and to assure they are safe to eat. Unfortunately shellfish (mainly molluscs) are responsible for serious outbreaks of food poisoning and their reputation is also vulnerable to fears about water pollution. Fourteen deaths due to Shigellain the Netherlands in 1984 were attributed to in-fected shrimp imported from Asia. Food safety concerns prompted precautionary measures in the USA in 1999 when the FDA banned interstate marketing of vacuum-packed fresh seafood including crayfish tails. Vacuum packing prolongs shelf life by removing air and by slow-ing the growth of spoilage bacteria, but the bacterium Clostridium botulinumcan grow in anaerobic conditions ° at temperatures above 2 C and produces deadly toxins (Anon. 1999a). Such fears about the safety of crusta-cean products should however be kept in perspective. Shrimp, for example, continues to represent one of the safest forms of muscle protein consumed in the world and it is much safer than fish or chicken. Problems usu-ally involve mishandling or cross contamination in retail
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Plate 3.1 Thai women processing farmed shrimp. Note that in this picture the face masks are not always covering the nose properly.
or food service settings or in the home rather than defec-tive productper se(Otwell & Flick 1995). Further food safety concerns are prompted by the pos-sible misuse of antibiotics on farms and the use of adul-terated feed. The uncontrolled use of oxytetracycline and oxolinic acid in some shrimp ponds in Thailand has led to the detention of exports to the USA and Japan (Sri-somboon & Poomchatra 1995). Penicillin residues in farmed shrimp triggered allergic reactions in consumers in Germany and prompted importers to seek guarantees that their shrimp supplies originated from farms that do not employ antibiotics. Delaying the harvest for an ap-propriate period following most drug treatments allows residues to be purged from the flesh (Mishra & Singh 1999). However, pesticides and heavy metal residues may also accidentally accumulate in farmed crustaceans from the water or from food. For example the contamina-tion of animal feedstuffs by dioxins in Belgium in 1999 raised concerns about possible contamination of aqua-culture products and highlighted the need for traceability in feeds and feed ingredients. In most countries strict microbiological and quality specifications are laid down for imported foods by health or food authorities and shipments may be detained for inspection and destroyed if they are substandard. How-ever, random sampling and detention of defective lots is an ineffective method of assuring food safety and it is being replaced by the improved approach known as HACCP. This can be characterised as a shift in empha-sis away from quality control and towards quality assur-ance.