As world population continues to expand, with a projected increase from 6 billion people in the year 2000 to 9-10 billion by 2050, a great challenge for the agricultural sectors is to produce enough food to satisfy global demand. Beef and Poultry production have been affected by mad cow disease and avian flu. As the world population increases at a rapid pace, fish and fishery products are going to be one among the many food groups that will come under increasing pressure. Just about all the world’s natural fisheries resources are fully exploited, and the challenge for aquaculture is to expand, to meet the future shortfall in fish supplies. Compared to other food sectors, seafood consumption is ranked number four behind chicken, beef and pork.
World demand and supply
In 2003, the total global production from capture fisheries and aquaculture reached about 146.3 million tonnes (Mmt). Capture fisheries are stagnating with an increase of only about 1.6% since 1980, but aquaculture production has doubled over the past decade. China has been responsible for approximately 80% of this increase. In 2001, aquaculture produced about 28.92% and 31.69% of the total fisheries production. Three quarters of this global production were used for human consumption, the rest mainly for animal feed.Figure 2. Global fisheries production and aquaculture (Mmt) (Source: Tacon, 2005)
Fish constitute a significant part of world food supplies, accounting for around 16% of all animal protein consumed. Global demand for fish and fisheries products is projected to increase by almost 50 Mmt in the next fifteen years (from 133 Mmt in 2001 to 183 Mmt in 2015). Aquaculture holds much promise for meeting this increasing demand.
Aquaculture has been the fastest growing food production sector for over three decades and has shown a rapid expansion in the recent years with growth rate of close to 8.9% since the late 1980’s. In comparison, livestock meat production has been growing at around 3% per year over the same period and the output from capture fisheries has increased only 1.2%.
The major share of world aquaculture production in 2001 came from finfish (52%), and significant proportions from mollusk (23%), aquatic plants (21%) and Crustaceans (4%). The aquaculture production in 2003 was around 54.8 Mmt from 247 species with the value of 67.3 billion USD. The most distinctive character of aquaculture that differentiates itself from other food production sectors is that more than 92% of total production came from developing countries and around 91.2% come from Asia. Interestingly, the global organization, Infofish has observed that of the top 10 aquaculture producers in the world, eight are from Asia.MAJOR PRODUCTION AREAS
Aquaculture activities and production are scattered in every part of the world but the main production areas are located in Asia and Europe. Although production in North, Latin and South America has shown an increasing production, the number of species as well as tonnages is smaller than the former two areas (except for salmon and fishmeal production in Chile and Peru).Europe
The culture species used are as diverse as the European continent, with representation from more than 100 species. The single most important species is the Atlantic salmon with a production of about 730,323 metric tons per year. According to the United Nations’ Food and Agriculture Organization (FAO), Europe in 2003 produced 2,203,851 metric tons of fish and fishery products worth US$ 5.14 billion. Although, Europe contributes to less than 5% of the world production, the continent is the world leader in several aquaculture species, particularly Atlantic salmon, sea bream, sea bass and many shellfishes.
The European Union (EU) is now the second largest seafood market in the world after Japan. Seafood imported to the EU is about 40% of the total international fish trade. Currently, the EU imports US$ 25 billion of seafood and exports US$ 15 billion. All EU nations except Latvia and Estonia have seafood trade deficits. There is considerable room for aquaculture growth in Europe.Asia
The major share of global aquaculture production comes from Asia with China being the biggest producer. Statistics released by the FAO indicated that the top ten aquaculture producing countries are in Asia except for Chile and Peru. China remains by far the largest producer, with a fish production of 44.3 Mmt in 2002 (16.6 and 27.7 Mmt from capture fisheries and aquaculture, respectively), providing an estimated domestic food supply of 27.7 kg per capita as well as production for export and non-food purposes. The country contributed to 70.2% of global aquaculture production in quantity and 50% in value. India is ranked second, followed by Indonesia. Therefore, Asian fishery exports will continue to expand.MAJOR CULTURED SPECIES AND PRODUCTIONSalmon:
About 57.4% of salmon production is in northern Europe, 35.9% in America and 5.5% in Asia. The single largest producer is Norway with almost 45% of total production followed by Chile, an emerging salmon producer with about 26% of total production. In 2003, farmed salmon production was 1.83 Mmt estimated to be worth US$ 5.6 billion. Markets for salmon are mainly concentrated in northern America, Europe and Japan. Carp: Production of carps and other cyprinids far exceeded that for other species, accounting for nearly 42% (16.7 Mmt) of total fish production. Major producer are China, India and the eastern European nations.Tilapia and Catfish:
Tilapia production reports impressive growth, making it (after salmon and shrimp) one of the most successful aquaculture products entering the international trade. During the past decade, Tilapia capture fisheries has stabilized at around 600 000 MT, while its aquaculture production has grown from 0.55 to 1.67 Mmt. Catfish production shows a similar picture as Tilapia, but is still at a lower level. The total production of catfish is around 700, 000 MT, while total tilapia production reached 2.3 Mmt in 2003. Unit values for tilapia and catfish were surprisingly strong and even showed an increasing trend in recent years. The problems experienced by Vietnamese catfish in the US market do not seem to have had any impact on the overall performance of this trade.Marine shrimp:
Global shrimp production in 2003 was around 1.80 Mmt with a total value of US$ 9.32 billion. The major culture species was L. vannamei. The advantage of this species in the culture sector is due to the ability to control the whole production cycle, availability of genetic improvement strain, and its trophic status (eat low in the food chain therefore require low dietary protein and fish meal). Major production is from Asia (83.5%) and South America (15.8%). Shrimp products were sold in the Northern American, EU and Japanese markets.Freshwater shrimp:
Macrobrachium rosenbergii is the major freshwater shrimp cultured in China, India and Thailand. It is one of the best shrimp for grill and Tom-yum. In 2001, China led the global production of Macrobrachium rosenbergii with over 128, 300 mt followed by India (24 200 mt) and Thailand (12 000 mt). The global production of this species in 2002 exceeded 200,000 mt and projection for 2010 is around 400,000 mt. However, the drawback of this species is that female’s mature very early and so growth is slow as it uses its energy for reproduction. Therefore, research for producing all male and genetic improvement of this species might be needed. The species is becoming popular in the international trade and is showing signs of expansion.Outlook for aquaculture
The present status of research on genetic improvement in aquatic animals is far behind those being undertaken with terrestrial animals. In contrast with livestock and plant crops, which are industries have a long history in selective breeding and genetic improvements leading to advanced breeding approaches, very little work has been carried out with fish and shellfish. Only a few examples of such breeding programmes exist for fish e.g. Atlantic salmon in Norway, Nile tilapia in Asia, white shrimp and channel catfish in the USA. Breeding programs and genetic improvement is also being applied to the black tiger shrimp in Asia.
EU is probably the world leader in research and know-how in genetic improvement in aquaculture in areas such as population genetics, polyploidy and mono-sexing, quantitative genetics, genomics and transgenesis. The most successful work was carried out in salmonids resulting in an improvement in growth and flesh quality. However, USA, Canada and Asian countries are carrying out research with species such as channel catfish, shrimp and various kinds of shellfish.
The characteristics needed for genetic improvement in aquatic animal production include big size, fast growth, disease & stress resistance, monosexing, high quality carcass, and specific pathogen free (SPF) stocks while retaining a high genetic diversity.
Due to an increasing demand for protein from aquatic animal production, more research on genetic improvement in aquaculture is needed. Biological markers are the most important genetic tools for selecting the best strain. GMO’s may play a key role in future genetic improvement and they may become more acceptable solution for an environment friendly and sustainable aquaculture industry.TRENDS OF CULTURE SPECIES
Production of high value species such as Shrimp, Abalone, Seabass, Seabream and Salmon will continue to increase and dominate the trade to meet the demand in developed countries. Additionally, new and emerging species such as Cobia, Cod, Croaker, Halibut and Tuna will become the focus for research and development with regard to mass production and farming technologies.
Low value species such as Tilapia, Catfish and Carp will continue its role in the global aquaculture industry by contributing to both the international trade and supplying the local sectors. High diversity in the species used for aquaculture can be found among Asian countries. These include Grouper, Asian Seabass (barramundi), Pompano, Swimming crab, variety of omnivorous fishes, Sea cucumber etc. This is in addition to genetically improved strains of existing species.FEED
Feed is one of the most important factor affecting growth and survival of aquatic animals and also the most expensive component (contributing 30-50%) in the production process. In addition, feeds also have direct and indirect impact to the sustainability of the environment. The use of fishmeal for production of aquaculture feed has led to depletion of natural fisheries of many pelagic species. Loading of nitrogen and phosphorus into the environment through uneaten feeds and faeces has also led to growing concerns.
The level of inclusion of fishmeal in aquafeed varies among species. Carnivorous fishes (salmonids and other marine species) use 30-50%, while shrimps use between 25-30% of fishmeal in their diets. Lower amount of
fishmeal used in omnivorous fishes like channel catfish (3-6%) and herbivorous, carp and milk fish (6-10%).
The global aquafeed production was around 12.3 Mmt in 1998 and 15 Mmt in 2000. It is predicted that around 27 and 37 Mmt of aquafeed would be produced in 2010 and 2020. However, global fishmeal production has been relatively stable at 6-7 Mmt/year during 1985-2000, and the outlook for the next decade is predicted to be similar.Why is fishmeal (FM) the most common used ingredient in aquafeed?
FM has a high protein and energy content. In addition, an excellent amino acid profile, good source of n3-HUFA and minerals in a high digestible and palatable form has made FM the most preferred ingredient. The increasing demand for FM has led to limited supplies, increasing cost and public pressure. This will no doubt limit the future expansion of aquaculture. Several suggestions are in place to reduce the use of fishmeal. The replacement of FM by alternate protein sources that are more abundant, readily available, less expensive and sustainable is the major focus of research attention. Others solution include research and development on new protein sources, n3-HUFA sources and promoting the culture of omnivorous and herbivorous species.
Intensification of aquaculture has led to growing concern on the potential impacts to the surrounding environment. The two main output from aquaculture operations are solid waste (uneaten and excess feed, undigested feed and faeces), and dissolved waste (mineral leaching and by product of mineral metabolism). Poor quality of water induces fish stress, increase possibilities of diseases outbreak and lead to off-flavor, thus affecting both production and product quality.
Since major share of aquaculture waste is derive from feed, efforts to mitigate environmental impacts should focus on feed and feeding. Improve feed formulations; feed processing technique, handling and storage and onfarm management are important strategies for waste reduction from aquaculture.The challenges for aquaculture
ENVIRONMENTAL ISSUES AND SUSTAINABLE AQUACULTURE
The challenge for aquaculture in the new millennium is for sustainable development and expansion for achieving enhanced food security and economic development for the world’s population. The future of the
aquaculture industry largely depends on easy access to natural resources, such as land, water and fish meal for use in aquafeed. For some types of aquaculture activity, including shrimp and salmon farming, potential damage to ocean and coastal resources through habitat destruction, waste disposal, exotic species and pathogen invasions have raised concerns from critics.
Large amount of fish meal and fish oil requirements may further deplete wild fisheries stocks. Serious impact to the environment through disease contamination of wild and farm stocks, escape of exotic species from farms with a potential effect on wild populations and transfer of new diseases through imported alien species are also areas that need to be addressed.
Therefore, strict quarantine and control need to be imposed. Sustainability of aquaculture without any doubt depends on the maintenance of a good environment. The interactions between aquaculture and the environment are subject to increasingly strict controls and regulations. Environmental issues have become more involved in the global trade and consumers are becoming more and more aware of problems including limits on using fishmeal and fish oil to produce aquaculture species, organic aquaculture and eco-labeling. These would unavoidably affect the cost of production of fish and other aquatic animals.DISEASES AND THEIR CONTROL
The scare of avian flu and mad cow disease seriously affects poultry and meat production sectors. In intensive aquaculture systems, new diseases have emerged almost every 3-5 years. To combat the new diseases, efficient health management strategies such as rapid diagnosis, prophylactic treatment and biosecurity systems are required. Antibiotics will no longer be allowed to be used in aquaculture production in the future, therefore, other or existing strategies have to be improved for use in health/diseases control system such as vaccine, biological active compounds, probiotics, herbs or others natural products. Vaccines and genetic improvement techniques for developing disease resistant strain need also to be developed.TRACEABILITY AND FOOD SAFETY
Similar to other food production sectors, aquaculture has adapted to the new trends of consumers with the issue of food safety and traceability. Traceability enables the consumers or buyers, information on origin of the product, i.e. where it is produced, how it is produced and when it is produced. Thus, the consumers have a chance to select or support ecologically responsible product(s) or producer(s) which leads to minimized global environmental impacts and maintains sustainable production and trading.
The reason for initiation of traceability is due to the presence of chemicals and/or antibiotic residues in the products during the last few years. The traceability system requires every producer to know and record production information one step forward and one step backward. Therefore, if any problem occurs, it can be traced back for where and why the problem occurred and find solutions to the problem.
With traceability systems, the product can be recalled more rapidly so that the adverse affect can be minimized and problems can be solved faster and the non responsible producer will be out of business.
Traceability will definitely become a trade requirement in the future.OIL PRICE
Fuel is the major production cost in capture fisheries. In aquaculture, increase in oil prices makes oil the second most expensive component of the operational costs next to feed. Increasing oil prices since 2002 were largely attributed to different factors such as increasing global consumption (as a result of rapid economic growth in China and India) and reduced oil production (due to various natural disasters).
However, crude oil price may come down in 2007-2010, as predicted which may help to reduce the production cost in aquaculture.Conclusion
Globally, Aquaculture has developed at a rapid pace during the last few decades and has now become one of the fastest growing food production sectors. Latest reports from the FAO indicate that production from aquaculture has greatly outpaced population growth, with the world average per capita supply from aquaculture increasing from 0.7 kg in 1970 to 6.4 kg in 2002, representing an average annual growth rate of 9 percent. Unlike other food production systems, aquaculture use a number of species (over 247 species of aquatic animals and plants in 2003) and production systems varying from small household ponds to coastal shrimp ponds and new generation offshore sea cages.
Concomitant with this development have emerged concerns regarding the long term sustainability of the sector. Overdependence on marine resources such as fishmeal and fish oil, large scale disease outbreaks, pollution from the production systems via uneaten feeds and faeces, issues of food safety and increasing fuel prices have led to mounting criticism from various quarters regarding the actual benefits of aquaculture as a promising food production sector.
The key therefore is to devise means of improving current practices of aquaculture so as to make them environmentally sustainable including use of environment friendly and fish meal free diets, techniques to reduce waste loading into the surrounding environment and devising innovative strategies for maintaining bio security and food safety.Author: KIDCHAKAN SUPAMATTAYA
Aquatic Animal Health Research Center, Faculty of Natural Resources, Prince of Songkla University, Had Yai, Songkhla 90112 Thailand