Karen Richards, Chris Spencer & Clare Hawkins
(First published in TasRegions, 28 August 2014)
It only took the work of an afternoon and the following morning, but three of us may have just saved an entire species.
This may turn out to be the greatest achievement of our lives. But will you agree, when we tell you that the species involved was a 3 mm long snail?
It’s not easy being small and threatened. The plain fact of the matter is that when a species is beautiful, cute, or in some other way makes us stop in our tracks, it has a much better chance of getting our sympathy. Almost worse – small species are so commonly missed! It’s difficult to conserve a species on your land when you can’t see it.
Many of our smallest threatened species, however, have one great thing going for them – it can be surprisingly simple to save them.
Here’s what we did for the Viking Creek freshwater snail. Until mid-July, in the whole world, this species was only known from a 20 m stretch of creek south of Devonport. Previously, as part of work funded by NRM North, Karen and Chris had identified suitable, threat-free translocation sites in the surrounding catchment. They then added extra rocks in the 20 m stretch of creek, on which the snails, over time, laid some of their eggs. In July, we picked up 20 rocks covered in eggs, and placed them in two new sites. If we’ve picked sites that they like, we have now tripled the number of places in which the species lives!
Egg-covered rock | Eggs & hatchings in close-up | Chris Spencer re-locating rocks
We often hear that this or that species is ‘the most endangered in the world’. It tends to be a rather artificial comparison, but the Viking Creek freshwater snail was right up there. When a species is only known from a tiny area, it is so vulnerable. A single catastrophe, be it a severe drought, a landslide or a chemical spillage, could wipe out the entire species.
Further, a new threat had recently arrived in the area: an invasive snail known to outcompete relatives of the Viking Creek freshwater snail. Before we moved the rocks to the new site, we removed all adult snails from them, placing them back in the original stream, to remove any risk of moving the invasive snail to the new sites. The invasive snail does not lay eggs, but bears its young live – so we knew that if we just moved eggs there would be no risk.
So what have we saved, exactly? The Viking Creek freshwater snail is one of a large number of beddomeid snails in Tasmania, 41 of which are listed as threatened. Threats include reduction in water quality from fertiliser, cattle manure and sediment running off nearby land, trampling in streams by stock, and blocking of streams by weeds. You might think that, if there are so many different species, the loss of a few might not matter – but would you feel the same way if the snails were bigger? It turns out that the differences between each species are quite substantial, but very difficult to see due both to the size of the animal, and the shell hiding so much of the body. However, perhaps one day we’ll have the technology to appreciate this diversity better, and the snails will develop a rather larger fan club.
Karen Richards relocating snail eggs
There are lots of reasons to save species, and they can all be applied to the Viking Creek freshwater snail. They contribute to the stability of ecosystems they inhabit, providing food for many species. Anyone who’s kept an aquarium is aware of the abilities of aquatic snails to keep a place clean.
In every species there are a suite of genes found in no other, which may have specific values to us to be discovered centuries hence.
It can be argued that they have their own right to exist, and that future generations have the right to appreciate them.
And… OK, yes, some of us reckon, with their little black beady eyes and their long antennae, that they’re actually very cute in their own right. It’s just a matter of taking a closer look.
Everyone will have their own feelings about which species need help first. If we can’t get you on the wonders of snails, the brilliance of this one’s name, the delicacy of the hatchling snails in the photos, the species’ intense vulnerability – perhaps we can persuade you with our original, most coldly logical point – the cost benefit. This species was extremely threatened, and the required action to save it was very low cost and very feasible.
All that’s needed now is for us to briefly visit the new sites over the next few years to see whether the snails have established. Please cross your fingers for them!