EstuaryWatch Data Portal

Turbidity measured with turbidity tube <10 at top and <15 at bottom

I have had another look at the dissolved oxygen DO results for 27/6 as we were concerned about the very high readings. I went back to Augusta Street bridge the next day and took another reading which was considerably lower. Unfortunately I didn’t retest the other sites. I now believe that the meter was incorrectly calibrated so I think we should include a note to that effect on the data sheets. On re-reading the calibration data I didn’t allow enough time for the DO reading to stabilise.
I will allow more time for future calibrations. Jan Jones

H2S smell at bottom

Very low dissolved oxygen.

High turbidity in bottom sample.

Hydrogen sulfide smell in bottom sample.

No stratification (sea water). Lack of stratification possibly due to the creek being very low (not flowing) for 2 months due to lack of rain. High tides and very strong westerlies (sometimes gale force) have probably pushed the seawater back up the estuary. The estuary flowing in reverse with resultant seawater.

All samples of nearly pure sea water.

Lower than usual pH samples. pH meter checked against standard afterwards.

Met with Peter O'Brien on Monday 19th at Augusta bridge site tot discuss last months data. He as going to investigate storm water drains, including current citation oval damage to explain high B.O.D. and EColi count.

In the bottom 1 m of seawater at august St bridge hydrogen sulfide gas clearly detected. Indication of rotting vegetation, supported by very low and zero DO levels. This could indicate aftermath of high level nutrients (eg sewage spill), which needs to be investigated.

John Inchley rang Shire Health Officer, Peter O'Brien to inform him of data and he said they would investigate further (reported Mon, 29 Jan).

Jan Jones to investigate the use of drone to photograph estuary (and creek) with Balcombe Grammar.