The development of intensive grow-out-farms has been accompanied by an explosive growth in hatcheries, nurseries, feed-mills, input providers, factories producing frozen fillets, export companies and certification bodies in Vietnam and repacking facilities in the importing countries. At present, so-called vertical market-chain integration is occurring. A large share of the increased production has been achieved thanks to non-farmers investing in very large ponds (see Table 1 for the trend in farm size). Most farms have several ponds, and some companies own several farms. The density of striped catfish in ponds of 2 to 4 m deep is 30 to 90 kg/m2 prior to harvest, which is roughly equivalent to 15 to 25 fish/m3 (Lam et al. 2009).