The Opanuku stream at the Pipeline camp site provides an excellent
habitat for freshwater animals. The native bush is tall and varied in
composition, which ensures that the water is shaded for most of the day.
The trees also provide large amounts of organic matter for the animals
in the stream. Many of the invertebrates eat decomposing leaves and the
fish eat insects that live in (or fall into) the water. The fact that
the river is in the bush-covered hills at this point, means that there
is little artificial nutrient (or other pollution) added to the stream
in the runoff, the stony bed is clean, the river flows well and there is
very little sediment in the water.
Many of the animals found here can only survive in good quality water.
Mayfly and stonefly nymphs are the most sensitive to water quality, so
we have put them at the top of the list.
