Water fluxes, suspended solids distribution and water properties in the mouth of Menggatal estuary, Kota Kinabalu, Malaysia

A study on water fluxes, suspended solids distribution and water properties was conducted at the mouth of Menggatal estuary, Kota Kinabalu, Sabah in October 2009 and February 2010. Measurements were taken to study the inflow volume flux from the South China Sea into the mouth of the estuary as well as the outflow volume flux. Measurements were also taken to study total suspended solids distribution and water properties at the study area for a continuous 24-hour period. Current speed and direction were measured to determine volume flux for both inflow and outflow calculations. Water samples were also collected at four hour intervals for one tidal cycle for total suspended solids analysis. Temperature, salinity, pH and dissolved oxygen were measured in situ during the study. Results show that the inflow and outflow volume flux at the mouth ofMenggatal estuary is balanced, with negligible imbalance percentage (%) of 4.9% and 0.35%, respectively. Level of total suspended solids at the mouth of the estuary is high and the values are greater than 0.15 gil. The water is turbid and of poor quality regardless of tidal regimes. Water temperature at the mouth of the estuary ranges between 27°C and 31.2°C and is within the optimum range for estuarine and river mouth water. Salinity ranges from 22.8 pss to 30.6 pss and fluctuates according to tidal regimes. The value of pH ranges between 7.5 and 8.3 and dissolved oxygen level ranges from 2.3 mg/l to 5.3 mg/l. Level of dissolved oxygenreached 2.3 mg/l at its lowest level, which can be harmful to aquatic life found in the study area if the condition persists.