The Problem of Water Seepage in Aquaculture: A Preliminary Study of the Soils of Arac Fish Farm, Omuihuechi-Aluu, Rivers State, Nigeria

摘要

Preliminary study on the problem of water seepage in some ponds was carried out at the experimental fish farm of Nigerian Institute for Oceanography and Marine Research (NIOMR) /African Regional Aquaculture Centre (ARAC), Aluu, Rivers State of Nigeria. Soil profile holes of 4.50 cm diameter were drilled in the bottom of two ponds (6 and 9) to a depth of 2 m. Undisturbed soil samples were collected and subjected to visual inspection and particle size analysis. Visual inspection of top soil samples of pond bottoms across the fish farm was also carried out. Results of study so far carried out revealed that ARAC fish farm at Aluu, is sitting on a thin bed of a mixture of clay and lateritic soils. Immediately underlying this is a bed of sandstone of unknown thickness. The top cohesive bed for pond 6 analyzed 50.25% (clay); 43.87% (laterite); 3.84% (silt) and 2.01% (sand) while pond 9 analyzed 85.15% (sand); 13.73% (silt) and 1.10% (clay). The conclusions from the results are that the contamination of the clay soils by laterite soils conferred a condition of non-uniformity, increased effective porosity and permeability to the clay soil; and that the problem of inadequate water supply for the pond merely exacerbates the situation. The solution lies in sealing the pond bottoms by either importation of clay soils with appropriate compaction or bentonite treatment or both. Deepening the ponds will worsen the problem.