SS1.01 Assessing Potential Environmental Impacts of Aquaculture
Date: Thursday, June 13, 2002
Time: 10:30:00 AM
Location: Lecture Theatre
 
MassautL, Fundación CENAIM-ESPOL, Guayaquil, Ecuador, lmassaut@espol.edu.ec
Sonnenholzner, S, G, Fundación CENAIM-ESPOL, Guayaquil, Ecuador, ssonnen@cenaim.espol.edu.ec
 
SHRIMP POND WATER QUALITY COMPARED WITH ESTUARINE AND SEAWATER COMPOSITION IN ECUADOR
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Ecuador has a large shrimp farming industry that has developed since the mid-1980’s. Actual estimates of the area of ponds used for production range from 150,000 to 180,000 ha. In order to increase the yields of aquaculture ponds over natural productivity, feed and fertilizer are added. However, these inputs can greatly affect water quality inside and outside the production area. Comparisons between water quality analyses in estuaries, the sea, and commercial shrimp ponds show that in general pond water contains higher concentrations of nitrate, ammonia, soluble reactive phosphorus, total phosphorus, total suspended solids, and chlorophyll a. Exploratory study on the ability of aquaculture ponds to retain nutrients showed that 5-13% of the nitrogen and 5-23% of phosphorus added to the system are recuperated in shrimp flesh. In addition, ponds assimilate 0-35% of the nitrogen and 52-61% of the phosphorus; all the rest is generally discharged to the environment. A number of techniques are implemented and evaluated in an attempt to reduce the concentrations of nutrients, organic matter, and suspended solids from aquaculture effluents.