Regression analyses of the variables SOC and FY, AMB and FY showed linear relationships as indicated below:

1. fish yield FY = 49146.34 - 22654.3 (SOC), R=0.60 (standard error of Y estimate = 11.25%)
2. fish yield FY = 32600.18 - 836.04 (AMB), R=0.39 (standard error of Y estimate = 31.02%).

Analysis of the correlation between FY and some of the limnological parameters, as referred to above, were also done through quadratic equations. This reveals significant relations of FY with the parameters WpH, TA, WC, SOC, SK and AMB (based on respective correlation coefficient values). These quadratic relationships between FY and parameters, based on their respective best equations, are given below:-

1. FY vs WpH:
   1. FY = 1/(0.11940 * (WpH + (-6.996)² + 0.02812), R = 0.486
   2. FY = 31.550 * e^ ((ln(pH) - 1.931)²/(-0.01754)), R = 0.470.
2. FY vs TA
   1. Y = 31.37 * e^ ((ln(TA) - 3.922)2/(-0.2397)), R = 0.469.

   This result, shows maximum FY at a TA value of 50 and gradual decreasing yield trend at TA values both <50 and >50, corroborates with the field condition in the studied Lake.

3. FY vs WC: This relationship is found to be power law and is given by
   Y = 40.90 * 0.9935^ WC, R = 0.668.
   indicates gradual decreasing trend in FY at high values of WC - a situation which reflects the field condition in the studied biotope.
4. FY vs SOC
   Y = 23.06 * SOC^ (-1.313*SOC), R = 0.713.
   reflected the actual condition in the field with a gradual fall of FY at higher SOC values because more SOC reveals more organic decomposition.
5. FY vs SK
   1. Y = [ 17.88 + 3.2 * SK + (-0.162) * SK * SK ], R = 0.459.
   2. Y = 32.69 * e^ ((SK-10.60)/2) , R = 0.5656.

   portrayed a gradual decreasing trend of FY from SK values > 10 mg/100g upto which there has been an increasing trend from an initial high value.

6. FY vs AMB
   Y = 30.56 * 0.9387^ AMB R = 0.578.
   Y = 1/(-0.0004475 + (AMB) + (-5.946))2 + (-0.4520) , R = 0.848.
   

   revealed a decreasing trend of FY with higher AMB in the Lake. This tallies with field situation because more AMB would make less space available as fish habitat besides hindering their free movement.

   The stepwise multiple regression of limnological parameters (Table 1) indicate that the variartions in fish yield are mostly caused by DO, WpH, t, TA and ST. while variation in fish production due to variables such as FCO₂, WC, SpH, SOC, SP, SK and AMB are less. These analyses clearly indicate that factors such as DO, WpH, t, TA, ST and to some extent WT determines the fish yield in Lake Sone eco system.