(Any fauna that lives in a groundwater system)
Blind Syncarids, Isopods, Amphipods, Gastropods & Beetles
Near Narrabri NSW is Maules Creek, it is a semi arid region in the area from the base of the Nandewar Range (Mt Kaputar) to the Namoi River and I was out there to survey the creeks draining this area for freshwater crayfish. Whilst there I met up with Peter Serov. Peter is into all things aquatic with a particular passion for Groundwater Dependent Ecosystems (GDEs). This was all new to me so I teamed up with Peter and I helped him with his groundwater surveying in the area and he helped me with my creek surveys.
Wow, was this an eye-opener. I had no idea as to the density and diversity of the fauna living in the groundwater under our feet. When Peter told me his forte was Syncarids I immediately thought that he was referring to the critters found in Tasmania. I’ve read books like “The Waterbug Book” and they are referred to as occurring in Tasmania and I’ve got them on my list to collect when I’m down that way. Imagine my surprise when Peter tells me they are in the area and we are going to collect some.
We met a local resident and had a chat to her and she had a bore on her property so we headed over there to sample the bore.
This was all new to me so I was rapt and eager to learn. All they did was take the cap off the bore and Peter dropped in a stainless steel tube with a large marble in the bottom (as it goes down the marble lifts and water flows through the tube but when he lifts up, the marble blocks the base of the tube trapping water so he can get a water sample from the base of the bore). He drops it in and lets it drop to the bottom of the bore, he then jigs it around a bit and drags it back up and out and then empties the tube of water into a 150 micro sieve to see what he has caught in his water sample.
First bore, first try and he caught Syncarids (a small freshwater crustacean – a blind shrimp type creature). Well I was amazed, his water sample was tiny, yet even so he caught critters. Well, before you know it we had the neighbours turn up and other locals and we had a crowd and for the rest of the day we went from property to property checking everyone’s wells and bores stopping along the way to check the creeks. The creeks had a bit of everything in them;
Yabbies Cherax destructor,
Shrimp Macrobrachium australiensis,
Goldfish Carassius auratus,
Spangled Perch Leiopotherapon unicolor,
Australian Smelts Retropinna semoni,
Galaxiids and macroinvertebrates, etc.
Almost without fail everywhere we sampled, whether a bore or a well we found Syncarids or Amphipods,etc. It was absolutely amazing the biodiversity and density of these subterranean creatures.
The area has, Syncarids, amphipods, worms, isopods, copepods, snails, and water beetles. These are all blind, colourless animals that are completely groundwater dependent. They exist independent of sunlight, living in the spaces underground through which groundwater flows. They have adapted their bodies, physiologies and life cycles to flourish in groundwater environments. This includes losing their eyes and pigment, being small enough or having attenuated body shapes to squeeze through the pores and crevices between the sand grains and cobbles. These groundwater environments are very stable compared with surface lakes and rivers so many of the organisms still retain primitive features and belong to groups that have long fossils records dating back to well before the dinosaurs so we are looking at animals that have been around relatively unchanged for an incredibly long time unaffected by the surface changes.
However, these unique ecosystems could be significantly altered by a change in the chemistry or volume of groundwater supply so I expect that in the future they may be included in future environmental studies and considered when developments are proposed that may dramatically alter the groundwater or threaten their existence. All groundwater has life of some sort and this can be used to monitor change to the groundwater environment in the same way that water bugs or fish are used to determine the health of aquatic ecosystems or birds, mammals and vegetation communities are used in terrestrial ecosystems.
The other fascinating aspect of groundwater ecosystems is that because most aquifers have been isolated for so long and the animals that live in them have also been isolated (as they cannot actively migrate out of them), just about every aquifer has its own endemic species that does not occur anywhere else. This truly represents a ‘Pandora’s Box’ of hidden biodiversity treasures for Australia.
It was a fantastic day and I’m grateful to Peter for opening my eyes and showing me the wonders of the subterranean aquatic world.
For further information on NSW stygofauna contact Peter Serov (firstname.lastname@example.org).