The habitat1 conditions2 at a monitoring site can influence stream life. A visual habitat assessment involves close observation of some of these conditions.
The SOSMART visual health check uses the following observations:
Smells – smell the water, note what you smell.
Obstructions – is there anything restricting water flow?
Stream bed – is there anything covering or smothering the stream?
Margin or bank – what do you see?
Appearance of the water – note what it looks like.
Rate of flow – note if it is fast or slow.
Top surface of the water – note your observations.
The visual habitat assessment also includes an observational drawing of the stream. Protocols recommend a habitat assessment length of about 50 m if the stream width is greater than 3 m or 20 m if the stream width is 1 m. This depends on access, safety and time.
The observational drawing identifies the photopoint3, various sampling points, water flow riffles4 and runs, stream bed composition and direction of water flow.
In addition to observational drawings, take photos of the area so changes can be viewed over time.
These Rivers and Us resources are in a downloadable PDF format. Use them as a guide to the scientific methodology for habitat assessment. They also contain discussion and reflection5 questions.
Transcript
VOICEOVER
The visual habitat assessment is one of the most important tools for monitoring stream health. It:
- provides data6 on possible impacts,
- identifies habitat features that could be affecting stream health, and it provides a visual health check that can be used to provide data for comparison over time.
ALEX DANIEL
What we’re doing is having a look at this space here as a habitat. So we’re going to have a look at the ecosystem7 here in the stream and see whether it’s a really healthy place for things to live. So other life – insects, animals, birds, fish – that sort of thing.
VOICEOVER
Start by recording what the weather8 is like at the time of your assessment and also the rainfall for the previous 48 hours.
Observe closely and record the aspects that make up the SOSMART visual health check for your stream. Smells – what does the water smell like?
Obstructions – is there anything restricting water flow?
Stream bed – is there anything covering or smothering the stream?
Margin or bank – what do you see?
Take note of the vegetation9 along the stream banks. Vegetation is very important to stream health. It provides shade, reducing the water temperature10. It filters nutrients11 and catches sediment12 in run-off13. Vegetation also stabilises the streambanks.
Appearance of the water – what does it look like?
Rate of flow – is it fast or slow?
ALEX DANIEL
The next one we would look at is the flowing water. We’re going to look at riffles, pools and bends. So do you guys know what I mean when I say riffles? It’s when the water is really moving up and down, and what do you think it’s good for? It’s when the water is really moving up and down, so it’s putting – it’s aerating the water. It’s getting lots of oxygen14 in, and the animals that live in the stream need that oxygen to survive. So we want a bit of variety with bends, pools and riffles.
VOICEOVER
Top surface of the water – what do you observe?
Finally, make an observational drawing that identifies the key features of your stream.
If you have done riparian planting15, note the size of the plants. That way, you can see their progress over time.
And add in the places you carried out the monitoring. This is an essential piece of your monitoring data that will enable you to monitor at the same place next time.
Acknowledgements
Alex Daniel
Waikato Regional Council
The Fairfield Project
Hannah, Jess and Sam, Waikato Diocesan School for Girls
Footage of algae16 mats in river, Cawthron Institute
Footage of stream riffles with leaf litter, NIWA
Acknowledgement
This video has been developed in partnership with the Waikato Regional Council as part of the Rivers and Us resource.
