Quantitative Analysis of the Relationship between Different Physico-Chemical Parameters and Fish Yield in Some Selected Fish Ponds in South- East, Nigeria

Abstract

Study was conducted to determine the relationship between the different physico-chemical parameters and fish yield in some selected fish ponds in south- east, Nigeria. Water samples were collected from different fish farms for 6 months for analysis. The physico-chemical parameters analyzed were transparency, temperature, pH, dissolved oxygen (DO), carbon dioxide (CO₂), chloride (Cl^-), alkalinity, and hardness. Simple scatter plots were used to determine the quantitative values of each parameter and their effects on the yield of fish. The result showed that Temperature (r=0.025), pH (r=0.000) and DO (0.017) correlated negatively with fish yield in concrete fish farms but transparency (r=0.002), CO₂ (0.006), alkalinity (r=0.543), and hardness (r=0.451) showed positive correlation with fish yield in the same concrete fish farms. Chloride (r=0.006) indicates a near nil effect on fish yield in concrete fish farms. A different scenarios (opposite) were observed in earthen fish farms in the cases of temperature (r = 0.044) and DO (r =0.711) which showed positive correlation with fish yield while the effects of transparency (r = 0.17), pH (r = 0.008), alkalinity (r = 0.022) and hardness (r = 0.188) on fish yield in earthen fish farms were negative. pH (r =0.008) had a mild positive correlation with fish yield in earthen fish farms.  Although the mean values of DO in concrete and earthen fish farms were almost equal in concentration but its effects were more felt in concrete fish farms than earthen fish farms which are more or less like open system. The effect of chloride (r = 0.000) on fish yield was nil in earthen fish farms but negligibly mild (r = 0.006) in the concrete fish farms. Also, CO₂ (r = 0.017) in earthen fish farms has similar negligible effects on fish yield as in concrete fish farms (r=0.006). The study therefore recommends strategic management of water quality especially in concrete ponds to ameliorate the negative effects of those parameters such as temperature, pH and DO that have direct bearing on fish yield.