Sediment Quality of Extensive and Modified Extensive Shrimp Culture Systems in Southwest Coast of Kerala

Abstract

The physicochemical features of the sediments of extensive and modified extensive Penaeus monodon Fabricius culture systems on the southwest coast of Kerala was studied during shrimp culture season (June 2006 - May 2007). Mean sediment temperature in extensive and modified extensive system was at its lowest during monsoon and the highest during pre-monsoon. Sediment pH was below neutrality in both the systems all through the culture period. Sand was the main constituent (60.6 to 78.1%) of the sediment followed by silt (11.4 to 28.6%) and clay (10.6 to 13.7%) in extensive and modified extensive systems. There was significant seasonal difference in organic carbon, sand, silt and clay in both the culture systems (P<0.01). However, between the two culture systems, there was no significant difference in any of the parameters. The study showed that the two culture systems did not differ significantly with regard to their sedimentological features, which in turn suggests that the additional inputs in the modified extensive system did not enhance the sedimentological properties of the system.