2. Background

In 2002, global aquaculture production reached 39.8 million metric tonnes with a value of US$ 53.8 thousand million. This represented an increase in production of 5.3 percent by weight and 0.7 percent by value over the previous year. Although cultured crustaceans represented only 5.4 percent of total production by weight, they comprised 20.1 percent of total global aquaculture by value in 2002. Despite being affected by serious disease outbreaks in both Latin America and Asia, the annual rate of growth of the cultured shrimp sector grew by 6.8 percent (by weight) between 1999 and 2000. Although this had dropped to 0.9 percent during 2002, these growth rates are still high relative to other food producing sectors. The global shrimp production has decreased to more modest levels over the last decade (averaging 5 percent) relative to the double-digit growth rates which were observed during the 1970's (23 percent) and 1980's (25 percent) (FAO Fishstat database^[8], 2003).

Modern shrimp farming began in the late 1960s and early 1970s, when French researchers in Tahiti developed techniques for intensive breeding and rearing of various Penaeid shrimp species including Penaeus japonicus, P. monodon and later P. vannamei and P. stylirostris. At the same time, in China, P. chinensis were produced in semi-intensive ponds, while P. monodon were produced in small intensive ponds in Taiwan Province of China. Also, in North America, the Department of Commerce's National Marine Fishery Service (NMFS) began funding research into shrimp farming.

Early Penaeid culture efforts in the Americas during this period concentrated on indigenous species including P. setiferus in Panama, P. aztecus and P. occidentalis in Honduras and P. aztecus and P. duorarum in southern USA, P. schmitti and P. brasiliensis in Brazil, and then P. stylirostris in Panama. However, initial work with P. vannamei in 1972 gave much better production than the other species. When Brazilian authorities initially banned the import of P. vannamei, culture was started in Panama in 1974. Although P. stylirostris was producing well in Panama, and eyestalk ablation led to easy spawning, year round production was impossible. The better results obtained with P. vannamei encouraged work on maturation and spawning of wild broodstock. Once nutritional requirements of the broodstock were met, eyestalk ablation techniques led to successful all year reproduction of P. vannamei, and it replaced P. stylirostris in Panamanian commercial production in 1978 (Rosenberry, 2001).

By the mid-1970s, fisherfolk and hatcheries were supplying large numbers of postlarvae (PL) shrimp and global cultured shrimp production started to increase rapidly reaching 22 600 metric tonnes in 1975. At this time, Ecuadorian farms were starting to produce large numbers of P. vannamei through extensive culture. Mainland China and Taiwan Province of China were producing P. chinensis semi-intensively and Thailand's P. monodon industry was just starting. Over the next decade, production grew to 200 000 metric tonnes, 75 percent of which was from Southeast and Eastern Asia. By 1988, production increased rapidly exceeding 560 000 metric tonnes principally as a result of increased production from Mainland China, Taiwan Province of China, Ecuador, Indonesia, Thailand and the Philippines (Rosenberry, 2001).

The first major production crash occurred in Taiwan Province of China during 1987-89, when P. monodon production suddenly declined from 78 500 metric tonnes to 16 600 metric tonnes, widely considered to be due to pollution, stress and increased susceptibility to pathogens, especially viruses. Following this crash, Chinese technicians and culture techniques spread around the world, particularly to Thailand, which saw the rapid development of many small intensive farms for P. monodon and which became the world's leading shrimp producer starting in 1993, a position it held until the year 2000.

In 1989, the first major crash in price for farm-raised shrimp occurred, when the farm gate prices for Asian shrimp fell from US$ 8.50 to US$ 4.50/kg. This was largely due to the extended illness and subsequent death of Japan's emperor Hirohito, which stopped shrimp consumption in Japan, which was the world's largest market at the time. This price decrease may also have been due to the oversupply of shrimp on the world's markets, which had grown by 25 percent over the fairly static 2 million metric tonnes level sustained for years from fishery, due to the increasing production from shrimp farms.

Source: FAO Fishstat (2003)

Figure 1: World production of cultured shrimp species (1994-2001)

Further crashes in production have subsequently characterized the world's shrimp farming industry, largely viral disease-related. These occurred first in Mainland China, when production fell from 207 000 metric tonnes in 1992 to 64 000 metric tonnes in 1993-1994 due to White Spot Syndrome Virus (WSSV) outbreak. Similar continuing problems in Thailand, the Philippines and Indonesia, first with Yellow Head Virus (YHV) and then WSSV, have occurred since the early 1990s. A similar scenario has also been seen in Ecuador and the rest of Central America owing to bacterial and then viral disease problems, first with Taura Syndrome Virus (TSV) in the mid-1990s and then WSSV from 1999 onwards.

In Asia, during the early 1990s, Viet Nam, India and Bangladesh also developed sizeable industries with P. monodon. In Latin America, Honduras, Mexico and Colombia developed large semi-intensive industries based on P. vannamei and P. stylirostris. Through the early to mid-1990s, production hovered around 700 000-900 000 metric tonnes as some countries experienced severe production downturns, due largely to YHV and WSSV in Asia and TSV in Latin America, whilst others developed their industries (Table 1). Subsequently, production has risen again, largely due to increased competence in the management of viral problems with P. monodon in Asia, and the closing of the life cycle and development of domesticated and genetically selected lines of P. vannamei in Latin America, and particularly now, with the increasing culture of P. vannamei in Asia.

Table 1: World production and value of cultured shrimp species (1994-2001)

Source: FAO Fishstat (2003)

Globally, marine shrimp continue to dominate crustacean aquaculture, with three major species accounting for over 75 percent of total shrimp aquaculture production in 2002 (the giant tiger prawn, P. monodon; the fleshy prawn, P. chinensis; and the whiteleg shrimp, P. vannamei) (Figure 1). The giant tiger prawn only ranked 16^th in terms of global aquaculture production by weight in 2002, but it ranked second in terms of value at US$ 3 371 thousand million (second only to the massive production of freshwater silver carp).

World cultured shrimp production levels reached 1.48 million metric tonnes by 2002 (accounting for more than 49 percent of global capture and cultured shrimp production) (FAO, 2002; Chamberlain, 2003) (Table 1 and Figure 1). The contribution of P. monodon has remained stable at around 600 000 metric tonnes from 1994 through 2002, whilst its contribution to world shrimp production has declined from over 63 percent to 40 percent in 2002, as P. chinensis and now particularly P. vannamei productions have increased to more than 500 000 metric tonnes between them (FAO, 2002). Current estimates compiled for this report suggest that the rapid growth of P. vannamei culture in Asia, particularly in Mainland China and Thailand, may result in a production of nearly 500 000 metric tonnes of Asian P. vannamei in 2003 (Table 3).

Projections estimate that the world's shrimp culture industry will continue to grow at 12-15 percent/year, although prices in the US market have been steadily decreasing by 4 percent/year from US$ 10 to US$ 8/kg since 1997 (National Marine Fisheries Service website^[9]) (Figure 1). In 2003, first quarter figures showed record imports into the US market, with fairly stable prices, although consumer confidence and the US and Japanese national economies remain low. Additionally, the increasing oversupply of P. vannamei from first Mainland China and soon other Asian countries, as well as Brazil and other South and Central American countries, will probably lead to a continuation in declining prices. This is compounded by the slow growth rate (9 percent/year since 1996) of the world's largest shrimp market, the USA (importing 430 000 metric tonnes in 2002), the slow European market (300 000 metric tonnes in 2002) and the declining Japanese market (250 000 metric tonnes in 2002) (Chamberlain, 2003; Globefish website^[10]; NMFS website) (Tables 8 & 9 and Figure 3). Costs have also increased as the industry adjusts to increasing international standards on product quality and the environment, putting huge pressures on the majority of the world's shrimp producers. In Thailand, declining prices and uncertainty over market access have led a signficant number of farms to shift back to the culture of the indigenous Penaeid, P. monodon in 2004.