Naturalists' club goes on day trip
CATCHMENT officer for MRCCC Dale Watson led the Gympie and District Field Naturalists’ Club’s August field trip to Chris Mangold’s Calico Creek property.
Members were also fortunate to be joined by botany experts Marc Russell and Ernie Rider who led a group through the interesting creekside vegetation.
Those most interested in bird watching had good sightings of 39 species.
Mr Watson explained the importance of monitoring and improving the habitat for aquatic life and demonstrated the electronic testing carried out regularly by a number of landholders throughout the catchment.
He said there is trust and respect for the data collected by waterwatchers since 2000.
While stirring rocks in the creek to release bugs for identification, Mr Watson showed samples of native aquatic plants including hydrilla, curly pondweed and ribbonweed.
He said Lungfish lay their eggs in ribbonweed beds in the Mary River.
Specimens collected and sorted for identification included mayfly, damsel fly, caddis fly and shrimp, also some gudgeons.
Rainbow fish and mullet are seen in the creek as are also juvenile Mary River cod.
Mr Watson was also guest speaker at the meeting the following Tuesday night and the subject of his presentation was Aquatic Macroinvertebrates.
He said they are little animals without backbones that live in most fresh water systems throughout the world. Though they don’t have a backbone, they are the ‘backbone’ of the ecosystem, breaking down organic material and bio indicators of water quality.
Mr Watson’s presentation of the secret life of macroinvertebrates showed that caddis flies weave sand and weed together to form portable cases, whirligig beetles have four eyes and an organ that can sense movement in the water, dagonfly and damselfly larvae have a mask used for catching prey and mayfly larvae have abdominal gills that flutter like feathers.
There are about 50 mayfly species in Australia.
Yabbies, shrimps and crabs are other macroinvertebrates. Crustaceans have a statolith in their head with sand grains for balance.
After the animal moults the grains of sand have to be replaced and this is done by rubbing the head in sand or placing grains into the hole in the head with pincers. As the shell grows the hole covers over.
With his new digital USB microscope Mr Watson was able to project enlarged images of some of the specimens collected on the outing.
The wildflower outing to Harry Spring’s Hut on September 19 will be led by Ian Smith.
Guest speaker at September 21 meeting will be Rachel Lyons, Biodiversity Conservation regional coordinator for BMRG talking about the region’s threatened species.
Inquiries Peter and Bevly Hughes on 5484 0198 or Bruce and Joy Drummond on 5482 1171.