Gairdner River

Five sites were sampled on the Gairdner River; they are shown on the map above. Photographs are available for each site:



The Gairdner River was sampled on the 16th to the 18th of October 2006.


Three different types of fish were found, the Gobi, Hardyhead and Spotted Minnow. Shrimps were also found along with Koonacs. Pictures of these species can be viewed in the gallery.

River foreshore vegetation condition

The condition of the vegetation bordering the river at the sites sampled varied from pristine to degraded. The lowest site on the river and one on Calyerup Creek had vegetation near the sites in the best condition. The remaining sites were more degraded with more weeds.

Water Quality

Water samples were taken once from each site so while they help describe the water quality at the time of sampling they can not be used to explain the overall condition of the river for the rest of the time.

The temperature of the water at the sites ranged from 14.79 to 19.61°C.

Salinity decreased down the river from above seawater at 50.2ppt at the most upstream site (GAI04) down to 17.3ppt at the lowest site GAI01. Nyerilup Creek site was 30.45ppt which is just below seawater at about 35ppt. The site on Calyerup Creek was much fresher with a salinity of 7.83ppt.

The acidity ranged from just below neutral at pH 6.6 in the main channel to pH 8.98 which is more basic at the site of Nyerilup Creek.

For total phosphorus, sites GAI02 and GAI05 had the highest levels with 210 µg/L and 98 µg/L respectively. The remaining three sites had lower levels between 20 and 34 µg/L. Total nitrogen concentrations reduced as the sites went downstream. The highest level was recorded at site GAI05 with 2500 µg/L. The lowest concentration was recorded at the lowest site GAI01 at 990 µg/L.