Improving the environmental sustainability of semi-intensive shrimp farming in Colombia

The shrimp industry in Asia and America recently experienced several disease outbreaks that caused huge economic losses. Authors argued that poor management practices and deterioration of coastal water quality probably caused this situation, and shrimp farming is commonly considered unsustainable. The environmental sustainability of shrimp culture is suspected to be poor because of the high use of fish meal in feed and other natural resources, and the contamination of surrounding coastal waters by farm effluents.; This work investigates ways to improve the environmental sustainability of semi-intensive shrimp farming in the Caribbean coast of Colombia. It considers social and economic issues that are closely linked to environmental sustainability. Economic and social impacts of shrimp farming along the Caribbean coast of Colombia appeared to be positive, so it is a good development tool there. Economic sustainability was improved recently by the development of a local strain of shrimp free of some diseases and resistant to others. Nevertheless, shrimp production and economic returns appeared to depend on cyclical environmental factors. Returns during the dry season are close to zero. Lower harvests during the dry season result from low shrimp growth. This problem was not due to temperature fluctuations, but a correlation with salinity conditions was found. Since technical solutions to this problem are not available, new management strategies should be developed to obtain a better economic return during the critical period.; Under current management practices, shrimp feed almost exclusively on pelleted feed. This suggests that research should focus on improving feed quality, in particular digestibility, and feeding techniques. However, findings showed that benthic diatoms could be a significant source of nutrients. Research should be conducted on how to favor the development of this flora. Natural foods in the pond could be used to reduce the need for fish meal and essential nutrients.; Waste generation is inherent to semi-intensive shrimp farming. Mangrove wetlands could be used as a sink for suspended solids and nutrients discharged by shrimp ponds. A study of an experimental system showed it is efficient for removing suspended solids from effluents, but the nutrient assimilation capacity of mangrove wetlands can be overcome. These results pointed out the difficulty of using natural ecosystems for water treatment.