Managing water pollution to revitalise the shrimp supply chain in Tam Giang Cau Hai Lagoon, Vietnam

The area of shrimps farmed in the Tam Giang Cau Hai Lagoon expanded dramatically from 1995 to 2004, but then declined steadily. An exploratory investigation of the shrimp supply chain conducted in 2009 revealed that well- established relational contracts between shrimp farmers and wholesalers had succumbed to environmental risk following persistent and widespread outbreaks of disease in the Lagoon. These outbreaks have been attributed to water pollution, which - in turn - has been linked to the rapid expansion and intensification of shrimp production. While privatisation of the lagoon bed encouraged farmers to adopt more intensive production methods, over- intensification can be attributed to the open access nature of lagoon water, which allows farmers to externalise the cost of their water pollution. This study evaluates a range of pollution abatement instruments against well-known criteria and concludes that transferable quotas for shrimp seed would be the most effective policy instrument given prevailing social, institutional, organisational and political conditions. Even so, the introduction and administration of seed quotas pose major challenges that would require co-management with local user groups