Table 3 Correlation matrix among the physicochemical and biological characteristics of Perumal Lake at station 3

Temperature

1

Turbidity

0.51*

1

Total suspended solids

0.41

0.93*

1

Conductivity

0.10

0.65*

0.74*

1

pH

− 0.24

0.49*

0.60*

0.63*

1

Total hardness

0.19

0.74*

0.76*

0.88*

0.66*

1

Dissolved oxygen

0.04

− 0.71*

− 0.79*

− 0.83*

− 0.82*

− 0.84*

1

Dissolved carbon dioxide

0.30

0.83*

0.80*

0.52*

0.65*

0.65*

− 0.75*

1

Chloride

0.01

0.69*

0.72*

0.93*

0.77*

0.91*

− 0.88*

0.62*

1

Nitrate

− 0.44

− 0.96*

− 0.96*

− 0.70*

− 0.50*

− 0.71*

0.70*

− 0.78*

− 0.69*

1

Sulphate

− 0.29

− 0.91*

− 0.87*

− 0.79*

− 0.62*

− 0.87*

0.89*

− 0.81*

− 0.86*

0.87*

1

Phosphate

− 0.26

− 0.88*

− 0.82*

− 0.83*

− 0.50*

− 0.82*

0.84*

− 0.70*

− 0.82*

0.84*

0.94*

1

Phytoplankton

0.72*

0.87*

0.88*

0.53*

0.35

0.64*

− 0.59*

0.74*

0.52*

− 0.82*

− 0.78*

− 0.70*

1

Zooplankton

− 0.25

0.60*

0.60*

0.70*

0.84*

0.67*

− 0.83*

0.65*

0.83*

− 0.62*

− 0.74*

− 0.68*

0.29

1