Waterbug Training

Waterbug Training

Many aquatic ecologists use waterbugs to tell them how polluted the water is in the streams that the waterbugs live in.  What are waterbugs?  The official term is macroinvertebrates.  Marcro meaning “large”, and invertebrate meaning “has no backbone”; or in other words, insects, insect larvae, spiders, mites, worms, yabbies and prawns.

Freshwater yabbie – a very big waterbug

On Sunday 25th August, experienced aquatic ecologist Cecil Ellis came from Sydney to train an enthusiastic group of volunteers from SLNC, neighbouring environmental groups and Scouts and Girl Guide leaders in waterbug sampling and identification. 

Cecil discussing the fine art of correct sampling techniques and safety

The main aim of the Waterbug Blitz program is to train people to become citizen scientists to captured data about the water quality of creeks and rivers across Australia.  The workshop was made possible through funding from Ipswich City Council.

Each of the different waterbug species can tolerate living in water of different quality.  Some species can only live in water that is near pristine, whist others can survive in water that is of poor quality.  The data provided the group with an insight into the total biodiversity of what is living in the water.  The abundance of waterbugs, total waterbug diversity, and type (taxa) of animals are combined to give a SIGNAL score (from 0 to 10) for the waterway.  SIGNAL stands for “’Stream Invertebrate Grade Number – Average Level”. If one finds a wide variety of taxa and species including those that can only tolerate clean water, then the habitat will get a high score, 8 – 10.  However, if only a few species are found, or only those species that can tolerate living in poor water quality, then the score will much lower, 1 – 3.

After collecting our samples – in this case from a reach of Opossum Creek above Discovery Lake – we sat down to identify what we had.  Whenever we saw something moving, we caught it and put it in our sample tray for closer identification.  We were assisted in this through the use of the Waterbug App on our smart phones.  The app took us through a series of taxonomy questions based on physical characteristics that allowed us to identify the taxa of the organism down to Order, and sometimes Family level (but not species).  The data was entered into our smart phones, summarised into a SIGNAL score and then sent off (including photos) to the national database.

When the sampling site was first scouted there was flowing water.  However, by the time of the training we were lucky that there was still some water left ponded in the creek.  The expert said that in this semi-urbanised environment, and without flowing water, that the water quality would be poor – especially with regard to the dissolved oxygen that all aquatic organisms need to breathe.  Nevertheless, we found 22 different taxa, including caddis fly larvae, dragonfly larvae, damsel fly larvae, mites, a blood worm, freshwater prawns and two types of yabbies.  However, the SIGNAL score came out as 3.4, which is regarded as poor, although the expert said that it was better than he expected. 

His parting words were – after it rains, we should go out again and practice our new skills.  We’re still waiting for some decent rain to get the creek flowing again!

Trainees relax after a long day of identification
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