Temporal variation in the ecology of Kuramo water, Lagos Nigeria

Abstract

Temporal variation in the ecology of Kuramo water was studied in the Lagos lagoon complex. Physicochemical parameters and heavy metals concentration were analyzed. Eight sites were marked using the geographical positioning system (GPS model-12). Water chemistry was determined for 8 months and sampling was done along designated transects. Water pH (9.51±0.74), Dissolved Oxygen (8.53±1.54

mg/L) and Temperature (29.31±1.030C) were the most stable of the measured variables. S04 -2 (69.17±17.66 mg/L), COD (13.67±1.46 mg/L), Fe (0.23±0.16 mg/L), Ca2+ (409.82±6.66 mg/L) and Cu (0.38±0.14 mg/L) were also relatively stable. In contrast, Salinity (1.66±2.08‰), Conductivity (1043.10±164.59ìS/cm), Cl-(111.76±21.35mg/L), TDS (521.45±82.36mg/L), TH (542.67±91.73mg/ L), BOD (6.22±1.02 mg/L), Alkalinity (46.54±16.77 mg/L), TSS (11.10±7.91 mg/L), and N-NO3-(1.77±1.67mg/L) temporally varied and values of all analyzed variables were significantly different over the period of eight months (p<0.05). There were no significant variations across sampling stations (Spatial). These fluctuating, unstable variables explained in a great deal the influence of: anthropogenic impacts, season, and its geomorphological proximity with the Atlantic Ocean (< 100m apart). Conductivity showed high significant correlation with TDS, TH, Ca2+, and S04 -2. During the rainy season, an immense volume of salt water enters the Kuramo water, therefore making it incorrect to refer to the Kuramo as fresh water body. Life in this water system is thus subject to temporal variation; from fresh in January - April (0.3 - 0.5 ‰) to brackish condition between May and July (5.1 - 5.3 ‰). Thus, only euryhaline species can survive such variabilities.

Key words: Temporal variation, ecology, Kuramo, anthropogenic impacts, correlation coefficient matrix, euryhaline.