Autumn Waterbug Watch 2016

Waterbug Watch is a citizen science initiative of the Australian Museum

Information derived from macroinvertebrate sampling can provide valuable insight into ecosystem health and is a powerful complement to water quality monitoring. The training day for the start of our 2016 Autumn/Winter sampling, was held at Duck Holes picnic area on beautiful McCarrs Creek, within Ku-ring-gai Chase national park

This location is a monitoring site for the Pittwater Coastal Environment Centre Streamwatch group. It is considered to be in good condition, supporting good macroinvertebrate diversity and the pools here are known to host Euastacus spinifer the Giant Spiny Crayfish.

The site has a variety of habitats within a short stretch of creek. This provided physical examples of riffles, runs, pools, leaf packs, aquatic macrophytes (vegetation), woody debris and edge habitats. Cecil provided both a site safety overview as well as a typically energetic sampling demonstration, interspersed with opportunistic observations of in-situ animals including a very large black spider, too fast to ID or photograph. This was followed up with a sampling effort by several volunteers keen to get some hands on guidance. Several buckets of collected material were readily obtained for the next stage of ‘tray gazing’.

The picnic area provided convenient space to establish the second stage of the training, easily accommodating three separate tables loaded with sorting trays and ID resources. Sub-samples taken from the collecting buckets were distributed between the tables and volunteers were asked to ‘separate and aggregate’ animals found in their trays. This stage simply requires volunteers finding as many different waterbug types as they can and placing representative specimens into ice cube trays. The emphasis being upon gathering a diverse suite of animals rather than getting many individuals from a few types.

It was great to see a number of Streamwatchers new to the discipline of Waterbug Watch, as well as the regulars. It was also great to see inter-group efforts at the same table. This is especially helpful because it brings learned knowledge and fresh eyes together, which benefits everyone. It was also heartening to see plenty of discussion among volunteers when the field sheets were being filled out. Thoughtful consideration was not limited to Waterbug ID but also to site description details. As usual, our volunteers were supported with a range of ID resources, including the Waterbug App, Streamwatch ID sheets, The Waterbug Book and of course expert opinion.

One of the interesting aspects of the day was a misidentification. Armed with the knowledge that this was a healthy creek supporting a range of sensitive fauna, one table tentatively identified a specimen as a Stonefly (Plecoptera) when in fact it was a Damselfly lacking a central gill structure, giving it the appearance of having two ‘tails’ typical of stoneflies. A great example of relying too heavily on a single couplet within a key. A Stonefly was correctly identified from another tray. Because Waterbug Watch is performed a few times per year, it is easy for everyone to lose confidence in ID ability and that is why we believe these training days are so important.

Hopefully we will have a very big skill honing, turnout, for our Spring/Summer training session in the Megalong Valley later this year.

Waterbug Watch continues to use a modified EPT Index, a richness score and a snail score and these values for the training day will be revealed in the Spring/Summer report. Needless to say, Stoneflies, Mayflies and Caddisflies were correctly identified as being present.