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Data 


Where We Test

The Bellingen Riverwatch program sees volunteers take monthly water quality data at 15 core sites and 7 additional sites across the Bellinger and Kalang Rivers.


 

What We Test For

Bellingen Riverwatch Volunteers conduct site assessments, take site photos and test water samples for the following indicators of river health:

  • Temperature;
  • pH;
  • Electrical Conductivity (Salinity);
  • Turbidity;
  • Available Phosphate; and
  • Dissolved Oxygen.

This is complemented by Faecal Coliform testing by OzGREEN and bi-annual water quality testing by Scientists from the Office of Environment and Heritage.


 

Data Across all Sites

The graphs below show the dissolved oxygen, phosphates and temperature data across the Bellinger River, Never Never River, Rosewood site and Kalang River from June 2017 to June 2018. 

When interpreting data, we have used the ANZECC Water Quality Guidelines for a healthy lowlands river system. This information will soon be available in a downloadable PDF.

A full data spreadsheet up until December 2018 is available here


Dissolved Oxygen

The ANZECC Water Quality Trigger Values for Dissolved Oxygen for moderately disturbed ecosystems for Lowland Rivers (less than 150m elevation) is 85 to 110 % saturation.

Results outside these values could be harmful to ecosystems. Anything below 85% is a threat to aquatic life and the macroinvertebrates that our turtles love to eat. Potential impacts outside ANZECC trigger values include lack of oxygen to support aquatic plant and animal life and fish kills.

Monitoring Dissolved Oxygen levels is very important as the Bellingen River Snapping Turtle (BRST) is able to supplement its oxygen uptake through cloacal (bum) breathing, reducing its need to come to the water surface to breathe.

The tables below shows the dissolved oxygen across the Bellinger River, Never Never River, Rosewood site and Kalang River. There are some results outside the ANZECC trigger values (outside of the green band).

Possible causes of results outside these values include stagnant water, organic waste such as sewage, fertiliser run-off and plant material in the waterway. Micro-organisms use the oxygen as they break down the organic matter.

 

Dissolved Oxygen across the Bellinger River

 

Dissolved Oxygen across the Never Never River and Rosewood site

 

Dissolved Oxygen across the Kalang River


Available Phosphates

Phosphates are the essential plant and animal nutrient that occurs naturally in very low levels in Australian soils.

The ANZECC Water Quality Trigger Values for Available Phosphates for moderately disturbed ecosystems for Lowland Rivers is 0.06mg/L. Results above 0.06mg/L could be harmful to ecosystems and may have the following impacts on waterways:

  • Abundance of algae and aquatic weeds which out-compete native plants
  • Waterways choked with vegetation
  • Increased Biochemical Oxygen Demand
  • Reduced Dissolved Oxygen
  • Reduced plant and animal diversity
  • Blue-green algal blooms
  • Eutrophication

The tables below shows the Available Phosphate levels across the Bellinger River, Never Never River, Rosewood site and Kalang River. There are some results outside the ANZECC trigger values (outside of the green band) in the Bellinger and Kalang rivers, but none in Never Never River and at the Rosewood site.

Possible causes of results outside these values include sewage, sediments from erosion, faeces from feedlots, dairies and pets, phosphate-based detergents, decaying plant material, fertilisers and industrial waste.

Scientists from the Office of Environment and Heritage are carrying out a comprehensive bi-annual water quality and macroinvertebrate surveys in December 2018 which will help identify the causes of elevated phosphate and nitrate levels.

Available Phosphates across the Bellinger River

 

Available Phosphates across the Never Never River and Rosewood site

Available Phosphates across the Kalang River


Temperature

The ANZECC Water Quality Trigger Values for temperature for moderately disturbed ecosystems for Lowland Rivers (less than 150m elevation) is site dependant.

The Bellinger River Virus (BRV) virus, the agent most likely to be responsible for the mortality event of the Bellinger River Snapping Turtle in 2015, has been found to reproduce in vivo temperatures above 28°C.

The tables below show the temperature data across across all sites. We have highlighted temperatures above 25°C in the red band.

We are seeing higher temperatures in our rivers due to climate change and loss of riparian vegetation. However, where and if we have refugial zones along the river is an important element we need to consider with climate change. When there’s no refuges, we see a drop in macroinvertebrates, and this poses a threat to our turtles.

Highly concerning are the temperature results above 30°C that have been recorded at Gordonville Crossing, where there is little to no riparian zone for our turtles.

As long as refugial cool spots remain in the river, elevated temperatures due to climate change is not a great threat to our turtles.

Bellingen Riverwatch scientists have noted that these results are taken from edge samples and have requested test extensions to the program in 2019 to ascertain temperature flux with depth. Bellingen Riverwatch is now seeking funding to add cross-sectional water temperature testing equipment,, including Mister Chains, to our kits.

Temperature across the Bellinger River, Never Never River, Rosewood site and Kalang River

 


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