Science Education News (SEN) Journal 2017 Volume 66 Number 4 December 2017 | Page 40

GENERAL ARTICLES
Swimming in Sand – Frogs and Sand-Mining at Smiths Lake (continued)
process involved the removal of the vegetation, the stockpiling
of the surface soil layers, the excavation of a dredge pit and
the construction of haul roads. Sand was sucked up through
a floating vacuum dredge, and a preliminary separation of the
sands was carried out on-site. The crude ore was then trucked
off-site to Tomago where the final separation of the rutile, zircon
and other minerals was achieved.
Figure 5: Dune Pond at Base of dune. Image: A. White.
I started off surveying the sites three times a year. In 1978 I began
my first surveys. The miners were still kilometres to the east, but
were ploughing through the dune at a fast rate. They eventually
reached my sites in 1981 and began clearing the vegetation from
the dune.
Figure 4: Sand mining at the eastern end of Bridge Hill Dune in
1976. Image: Barry Fox.
As mining was starting at the eastern end of the dune, I knew
that I had a few years to collect frog data prior to the arrival of
the miners, and then, if I was still around, maybe I could do some
follow-up frog surveys to determine what impact there had been
on the frogs (if any). Little did I know that I would still be doing the
follow up surveys forty years later!
In those early years I was able to record not only the frog species
that occurred there but also got some information about frog
numbers (Fig. 6). Over the duration of the study I recorded 13
frog species at the dune pond and 12 frog species at the swamp
site. The frog species present changed as the mine advanced,
the dune was stripped and dredged and the reshaping and
replanting of the dune commenced.
Frog Surveys and Frog Sites
I decided to set up two survey areas, one in a small pond that
sat at the base of the dune, the second in the dune swamp close
to this pond (Fig. 5). I chose these two sites because they were
close to the dune, had good frog populations, and were close
enough to the mine path to possibly be affected by the mine. I
carried out plant censuses in each of the areas, as well as doing
some basic water-quality measurements.
Figure 6: Searching for frogs in the swamp site. Image: A.
White.
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SCIENCE EDUCATIONAL NEWS VOL 66 NO 4