Aquaculture is the fastest growing food-production industry (Fig. 1). It all started in Asia, especially in China, but it was only in the last 3 to 4 decades that spectacular growth took place. Following the FAO global aquaculture production statistics for the year 2011, finfish make up about half of all seafood production, totaling 62.7 million mt with an estimated value of US$ 130 billion. Farmed aquatic algae or seaweed production was 21 million mt in 2011, worth US$ 5.5 billion (FAO 2013, Fig. 2) By quantity, Asia and the Pacific are responsible for nearly 90 percent of the production but, when expressed by value, Europe and Latin America make up 20 percent because their aquaculture products fetch higher market prices

Food Aquaculture and Business Aquaculture

Aquaculture practices can be classified under two categories: "food aquaculture," as practiced for millennia in Asia, and "business aquaculture," the more recent developments that have resulted in new practices with different systems and species (Fig. 4). Food aquaculture is exemplified by the traditional farming of freshwater fish in ponds in Asia. This food security approach is mainly to meet the farmer’s personal needs or for catering to very local markets. Until today this pond production practice is very important because it provides close to 15 million mt annually in China alone. Typical for this traditional food aquaculture is the integrated approach: farming of aquatic species in combination with other food production practices. Examples include fish and prawns in the ditches of rice paddies, feeding on periphyton, decaying plant material and insects, or fish integrated with the farming of terrestrial animals, such as chicken, ducks and pigs, using wastes and by-products as direct and indirect food sources.

Business aquaculture is a much more recent phenomenon. It was pioneered by the Japanese in the 1960s, and taken up later and further developed in Europe, USA, and Australia, in fact everywhere today, even in Asia. The main principle is to engage in the farming of species with high market value following capital-intensive business models. These modern aquaculture industries became feasible from new insights into the biology and life cycle of target organisms, for example, how parental stock could be induced to mature, or how the development of hatchery techniques allow the production of mass quantities of fry in hatcheries, fingerlings that can be stocked in high-density grow-out systems. Similar to the analogous plant and animal farming practices on land, business aquaculture is always practiced as a monoculture. Some typical examples include:

• more or less sophisticated cage structures, in fjords and bays, eventually moving out to more open sea areas;

• land-based systems operated in ponds, concrete raceways or tanks;
• recirculation systems that allow, maybe at a higher cost, production close to large urban markets, often in temperate and cold climates.

Success stories are numerous although most have or are continuing to experience rough times, including Atlantic salmon farming (Fig. 5), the classic example that has set the scene for many other types of business aquaculture. A first example is overproduction in the early 1990s in Norway, resulting in a severe financial crisis that was finally remedied by better marketing efforts, i.e. developing new outlets allowed for further expansion of the industry. Another example with Atlantic salmon has to do with diseases. Although much progress was made in disease control, a lack of basic biosecurity measures has been at the origin of recent devastating problems in Chile, such that it will take years to recover from the present economic setback.

In terms of scale of automation and production size, salmon farming is again leading the way. The farm in Figure 6 is situated offshore of the Trondheim fjord in Norway in a water depth of more than 50 m. The cages have a capacity of 1000 tons each and are operated by a crew of less than 10 people. High automation and thorough specialization are keys to success in this case.

Another success story is penaeid shrimp (Fig. 7). Following very profitable decades in the 1970s and 1980s, shrimp aquaculture experienced a very rough decade in the 1990s with severe disease problems caused by poor management practices and uncontrolled transfers of contaminated broodstock or postlarvae. The introduction of domesticated and SPF white shrimp Litopenaeus vannamei enabled more predictable growth of the industry.

Pangasius farming in the Mekong delta in Vietnam will enter history books as a typical example of business aquaculture adopted by a developing country (Fig. 8). Once maturation and hatchery practices were mastered, farming in floating cages and later in ponds expanded at a phenomenal rate. New markets, especially in Europe, were eager to introduce pangasius fillets as a cheap substitute for the more expensive generic whitefish from classic fisheries. It is a success story indeed, but one under serious threat because of biosecurity issues and limited attention to sustainability matters.

Another example of business aquaculture, albeit at a very local level, is the Chinese mitten crab industry (Fig. 9). Following the catastrophe with the white spot syndrome virus disease in the coastal shrimp farming sector in the early 1990s in China, a reconversion to mitten crab seed production really paid off. Annual production output, currently at 700,000 mt, continues to increase as local markets are further expanded and new farming practices, such as the polyculture of mitten crab in rice paddies, are successfully explored, even far inland in western China.

Outside Asia we often forget the success of mollusk farming, with more than 14 million mt annually, and seaweed production, delivering 16 million mt annually. These two latter forms of aquaculture deserve much more attention in the future.

Expectations for Future Aquaculture

What are the expectations for future aquaculture? What are the challenges and threats we face? Are there any opportunities? As world population continues to grow and consumers become increasingly convinced of the health benefits of eating seafood, market demands for aquatic products will further expand in the years to come. Fisheries are stagnating and might even level off, so aquaculture will have to grow even faster. Fresh water will become increasingly scarce in the decades ahead and we should turn more towards the oceans for a sustainable source of our seafood.

Read the rest of this article in the September 2013 issue of World Aquaculture Magazine here