April 2024: Chemical, Water Quality and Macroinvertebrate analysis

Alison Loxton
May 27, 2024
2 min read

Hi everyone

Please find attached the results of sampling for the month of April, 2024.

The weather experienced whilst sampling was not the best with some of the handwritten paper sampling records showing definite signs of being rained upon.

The significant flow of freshwater in the Coomera River caused sampling to undertaken twice, as the readings from the first trip (particularly turbidity and also salinity) were so abnormal as to be impractical to use.

In respect of the results, please find the following notes:

The water temperature readings indicate that mild conditions are being maintained; one wonders when the cooler weather will kick in
Salinity levels in the Coomera River lessened as we headed upstream, as usual, however there is a marked difference between the Koala Town Road site and the weir – 16.3 parts per thousand of salt as opposed to 7.7 parts per thousand of salt in what is only a couple of kilometres. Of the day of the latest survey the only fish I saw caught was at the Koala Town Road site, a bream of reasonable size.
The results of chemical analyses in Waterhen Lake showed continued good news for the Ammonia Nitrogen levels; the Reactive Phosphorous readings were a little higher than normal. One explanation for the lesser levels of Ammonium Nitrogen could also lie in the fact there are few breeding birds there at the moment, with egret species largely notable by their absence.
Salinity levels in Regatta Waters are lower than the main river; not too sure why this is so. Salinity levels normally mirror those of the Koala Town Road site.
Reactive Phosphorous levels in Regatta Waters are fine except for Site 4 where the S.E winds have pushed pollutants into the north western corner; and Ammonia Nitrogen levels are highest at Site I which is where a drain joins the main lake.