No abstract

Experts, government officials, and industry leaders concerned about the sustainability of shrimp aquaculture believe they know what farmers need to know and should be doing. They have framed sustainability as a technical problem that, at the farm level, is to be solved by better shrimp and management of ponds and businesses. Codes of conduct, standards, and regulations are expected to bring deviant practices into line. Shrimp farmers are often cornered in a challenging game of knowledge in which their livelihoods are at stake. In the commodity chain there are multiple relations with both suppliers and buyers, not all of which are trustworthy. The social networks shrimp farmers belong to are crucial for sifting out misinformation and multiplying insights from personal experience in learning by doing. Successful farmers become part of a learning culture through seminars, workshops, and clubs in which knowledge and practices are continually re-evaluated. The combination of vertical and horizontal relationships creates a set of alternative arenas that together are critical to bridging knowledge and action gaps for shrimp farmers. Government and industry initiatives for improving links between knowledge and practice for sustainability have largely succeeded when incentives are aligned: shrimp grow better in healthy environments, and using fewer resources means higher profits.

The shrimp production-consumption system is governed by a diverse and dynamic array of actors each drawing on institutions at various levels, from local through national to international. But, for the most part, the politics of consumption (plates), chains, and places are disconnected. Instead, shrimp producers face a myriad of institutional and consumer demands and the sustainability of the shrimp aquaculture production-consumption system is not merely a technical problem to be solved by better site selection and management of ponds. Instead, campaigns for, and against, consuming certain kinds of shrimp are launched in remote corners of the globe and standards, codes, and quality assurance schemes are developed and promoted by equally diverse set of actors, to guide and regulate practices of shrimp farmers and food processors. Furthermore, most initiatives take place with little or no consultation with shrimp farmers or the communities living in shrimp growing areas. Efforts to improve sustainability will require much greater attention to ways different stakeholders, in particular, shrimp farmers and affected communities in growing areas, are brought together with other actors, to deliberate and assess impacts, and to negotiate fairer distribution of risks and benefits in a sustainable production-consumption system. Associations based in producer locales and emerging platforms that bridge these arenas would be a good place to start.El sistema de producción-consumo del camarón se rige bajo un orden variado y dinámico de actores con base en instituciones de varios niveles, que van desde el local hasta el nacional y el internacional. Pero en su mayoría, las políticas de consumo (platos), cadenas y lugares están desconectadas. En cambio, los productores de camarón, se enfrentan a un sinnúmero de exigencias institucionales y del consumidor y la sostenibilidad del sistema de producción-consumo de la acuicultura del camarón no es sólo un problema técnico que se pueda solucionar con la selección de un mejor lugar y el manejo de los estanques. En cambio, se han lanzado campañas publicitarias en pro y en contra del consumo de ciertos tipos de camarón en áreas remotas del globo y las normas, códigos y los esquemas de controles de calidad se han desarrollado y promovido por un número igualmente diverso de actores, para dirigir y regular las prácticas de los cultivadores de camarón y procesadores de alimento. Además, la mayoría de las iniciativas se establecen con muy poca o sin consulta a los cultivadores de camarón o a las comunidades que residen en áreas de crecimiento de camarón. Los esfuerzos para mejorar la sostenibilidad requerirán mucha más atención a la manera como se reúnen a los diferentes participantes y en particular a los cultivadores de camarón, y comunidades afectadas dentro de las áreas de cultivos con otros actores para deliberar y evaluar los impactos y para negociar una distribución más justa de riesgos y beneficios en un sistema sostenible de producción-consumo. Un buen punto para empezar serían las asoc...

An experiment was conducted in rice ¢eld plots each of 30 m 2 to determine the appropriate combination of feeding and fertilization regimes for the giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879) cultured along with rice in rice ¢elds. There were four treatments: rice culture only with regular fertilization (A, control); rice^prawn integrated culture with regular fertilization (B); rice^prawn integrated culture with basal fertilization and commercial feed (C) and rice^prawn integrated culture with regular fertilization and commercial feed (D). Juvenile prawns of 1.5-g size were stocked on the third day after rice transplantation at a density of 2 prawns m À 2 and fed twice daily at 5% reducing to 2% of body weight during the experiment. The rice yield in treatment D (0.42 kg m À 2 ) was signi¢cantly higher than that in other treatments (0.34, 0.36, 0.34 kg m À 2 in treatments A, B, C respectively). Prawns grew signi¢cantly faster (Po0.05) in treatments C and D (23.8 AE 0.9 and 22.0 AE 1.7 g prawn À1 respectively) than in treatment B (14.7 AE 1.6 g prawn À1 ). Prawn production in treatment C (347 AE 13 kg ha À1 crop À1 ) was sig-ni¢cantly (Po0.05) higher than that (234 AE 30 kg ha À1 crop À1 ) in treatment B, while in treatment D (296 AE 53 kg ha À1 crop À1 ) it was not signi¢cantly di¡erent from that in treatments B and C (P40.05). Treatment C gave the highest economic returns among all treatments, followed by treatments D and B, indicating that the combination of basal fertilization and commercial feed is the most appropriate nutrient input regime for the rice^prawn integrated culture system.