Intensive prawn monoculture has repeatedly seen epidemics wiping out entire crops, or drastically reducing production. In Taiwan, aquaculture has boomed since 1984 and production reached 100,000 tonnes by 1987 -- 21 per cent of Asia's cultured shrimps. The yield nosedived to 20,000 tonnes in 1988, 10,000 tonnes the following year and, later, to less than 5,000 tonnes.

A study compiled by Ian Bird of the Earth Island Institute said: "The environment was hardly considered... and soon diseases typical of large scale monoculture struck at epidemic proportions."

Indonesia saw the same phenomenon, despite lower production targets. In 1991, Indonesia produced 140,00T of prawn from 20,000 ha. In Thailand, the industry boomed in the '80s, touching a production rate of 110,00 t by 1991. It is the only country that weathered the recent virus.