Waterwatch Australia national technical manual

Module 3 - biological parameters
Waterwatch Australia Steering Committee
Australian Government Department of the Environment and Heritage, 2004
ISBN 0 6425 4856 0

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Waterbug awareness

The procedures described in this section are a general guide for finding and identifying waterbugs by their body shape. The bugs may tell an interesting story about the waterway. Waterbug Awareness is not designed for groups wishing to undertake regular monitoring, but is useful for one-off events, such as catchment surveys, community field days, school projects or Waterwatch Snapshots events.

The result sheet required for Waterbug Awareness Monitoring is available in Appendix 1 of this module.

Choosing your sites

Your choice of site will be determined more by convenience and ease of access than by any other factors, for example, close to school. You can choose to sample from a riffle (shallow broken water with rocks of about tennis ball to soccer ball size), edgewater (close to banks), or amongst water plants in pools. At your site, there are likely to be many small animals which are not easily seen. Waterbugs can be found attached to rocks and plants, and hiding in leaf packs.

Equipment

When preparing to go to the site you will need to assemble general and specific equipment for the test method to be used (see Table 3).

Table 3: Field trip check list
Tick off the equipment that you need to take on your visit to the test site. Put another line (making a cross) when you are packing up to return.
Date              
General equipment              
Waterwatch Manuals              
Data result sheets              
Pens, pencils, note paper              
Marker pen (waterproof) / pencil              
Clean water              
Paper towel              
Rubbish bag              
First aid kit              
Sun cream and hat              
Camera and film              
Drinking water and food              
Gum boots / walking boots / raincoat              
Specific waterbug awareness equipment              
Kitchen sieve or net.              
White bucket or flat tray for holding samples during sorting.              
Four white containers, e.g. ice cream containers.              
Sorting implements to pick bugs from plants and rocks:              
tweezers (forceps);              
plastic spoon for large bugs (with 2-3 very small holes);              
plastic squeeze pipette for small bugs (about 5mm diameter);              
fine paint brush for lifting small bugs (small artist type).              
Emergency phone number              

Sampling method

Step 1
Choose your site(s). If you have a choice of sampling areas a riffle is best, otherwise sampling an edgewater, pool, or aquatic plant habitat is quite satisfactory.

Step 2
Sample one of the following areas at your site with the method described.

Riffles Rock
Rock rubbing method. At your riffle site, randomly choose several rocks of about hand size. Place the rocks in your bucket or tray, add stream water and with your hands gently brush off anything which could be living.
Kick method. Wearing gum boots, stand in the stream and kick the rocks to dislodge animals. Hold the net downstream to catch them.

Leaf packs in edgewaters or pools
Remove several handfuls of submerged leaves that have collected on the bottom and place them in the tray. Remove leaves one at a time and look closely for the presence of animals. Use tweezers, spoon or small paint brush to carefully remove anything that looks like an animal into the bucket or tray.

Aquatic plants in edgewaters or pools
Using a sieve or net, sweep backwards and forwards through any aquatic plants near the water’s edge to trap animals attached to the plants or swimming in the water. Do not collect too much material in your net. Empty the contents of the sieve or net into your bucket or tray.

Step 3
Label each white ice cream container with a name, that is, ‘worm-like’, ‘animals with shells’, ‘crayfish-like’ and ‘insect-like’. Add stream water to the containers (about 1 centimetre deep).

Step 4
Sort through your sample. Use a pipette, spoon or brush to transfer your waterbugs to the labelled containers for a closer look. Often the waterbugs are moving, so they are easy to find. Sort the bugs so similar looking bugs are all placed in the same container.

Note: There are four easily recognised types of waterbug (see Table 4). Identify each type of waterbug by their general features and from the drawings in Figure 6 - Waterbug identification guide. Or for more detailed identification keys see the section Identifying macro-invertebrates – further resources in this module.

Table 4: Types of waterbugs and tolerance to pollution
Animal body shape Tolerance to pollution
Worm-like animals, e.g. worms and leeches. They stick to rocks or sticks, or crawl slowly. They are generally tolerant of pollution.
Shelled animals, e.g. snails and mussels. They vary from tolerant to intolerant of pollution.
Crayfish like animals. These are generally intolerant of pollution.
Insect-like animals. They include a wide range of animals that have distinct heads, legs, bodies and tails. They come in many sizes and shapes and often move quickly. They are generally intolerant of pollution.

Figure 6: Waterbug identification guide and tolerance to pollution
Figure 6: Waterbug identification guide and tolerance to pollution

Step 5
On the Waterbug Awareness Result Sheet (Appendix 1), indicate which method of sampling (Step 2) you used and tick the box that best shows the number of waterbugs in each container (none, occasional or plentiful).

Step 6
Return all the waterbugs, leaf matter and rocks to your waterway. Wash your hands to remove parasites. Before you leave the site, make sure you have:

Step 7 (optional)
You may choose to pass your result sheet onto your Waterwatch Coordinator. If so, please complete the first part
– Background information. Your coordinator can help you to fill in this information.

What do the waterbugs in your sample mean?

The variety and number of waterbugs in your sample give you a sense of the health of the stream (see Table 5). Some waterbugs cope well with pollution or changes in their habitat, whilst others are very sensitive and die.

Table 5: Interpreting your results
If you find: It suggests:
Only one or two kinds of animals, e.g. worm-like animals, but many of them. Severe organic pollution.
A variety of animals, but only a few of each kind and the stream appears clean. Stream has undergone flooding (scouring) or the sample was taken during high flows from an area that dry a few days before.
No animals. Toxic pollution.

To more accurately measure the condition of the waterway, you will need to use the SIGNAL 2 score described later in the Module.

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