Shrimp farming systems in Hai Phong, Vietnam.

Abstract Hai Phong province is one of the main shrimp culture areas in north Vietnam. Its climate is influenced by two monsoon regimes. The April-September southwest monsoon is wet and hot, and the temperature is suitable for shrimp culture. The October-March northeast monsoon is dry and cold, and the temperature is not suitable for shrimp culture. Different shrimp farming systems take place along the entire coast depending on socio-economic and climatic conditions, seed availability, and farming methods to minimize the operating risk. The main cultured species in Hai Phong is black tiger shrimp, Penaeus monodon. The shrimp are either cultured in monoculture or integrated or cultured alternatively with mud crab (Scylla serrata), greasyback shrimp (Metapenaeus ensis)and seaweeds (Gracilaria gracilis and G. blodgettii). The main crop of black tiger shrimp is from April to September, when about 15% of farms practice integrated shrimp-seaweed culture and 85% of farms practice shrimp monoculture. Additional crops of shrimp or mud crabs are cultured during other months from September to March, while seaweed production is integrated with shrimp or crabs all year. Thus, four main shrimp farming systems can be found in Hai Phong: Single-crop shrimp farming, double-crop shrimp farming, shrimp-crab rotation farming, and integrated shrimp-seaweed-crab farming.