Status and environmental impact of shrimp aquaculture in East Godavari District, Andhra Pradesh

Abstract

ln India area under shrimp culture and production increased by 234% and 325%, respectively from 1990-91 to 2002-03. A comparison on status of shrimp farming between 1999 and 2004 was made and studies wore conducted on water and soil quality from different sources, their effect on soil salinisation to assess the impact of shrimp culture on the environment in East Godavari District, Andhra Pradesh. During 2004 the shrimp culture was in 18 mandals compared to 13 mandels in 1999. The number of farmers and area under shrimp culture has increased from 4814 and 6207.2 ha, respectively in 1999 to 10479 and 9252.82 ha, respectively during 2004. About 92.6 percent of farmers are having less than 2 ha area under shrimp farming during 2004 compared to 82.2 percent in 1999, reflecting the increase in number of marginal farmers. Shrimp farmers were practising improved/modified extensive farming of tiger shrimp with stocking density of 4-10 nos. of post-larvae per sq m. No adverse social or economic impacts have boon reported by the local population excepting conversion of rice fields into shrimp farms ln a few cases. The pollution indicators like ammonia N and chemical oxygen demand were well within the pormissible limlts indicating no adverse impact in the external source water. The electrical conductivity values of soil ranged between 1.0 and 1.89 ds m-1 in various agricultural fields adjacent to shrimp farms indicating that the soil salinity was not affected by the shrimp farming activities in the areas surveyed