Creek Life
Aquatic ecosystems comprise the animals, plants and micro-organisms
that live in water, and the physical and chemical environment
and climatic conditions with which they interact. Biological
indicators such as algae, macrophytes (aquatic plants), macroinvertebrates
(animals without backbones which are visible to the naked
eye) and fish are therefore excellent continuous monitors
of water quality, integrating the effects of past and present
exposure to contaminants or pressures.
Biological assessment provides information on biological
or ecological changes that may result from changes in water
quality but may also result from changes in physical habitat
(eg. increased temperature due to the removal of creek bank
vegetation) or biological interactions (eg. introduction of
exotic species or diseases). Biological assessment is a vital
part of assessing changes in aquatic ecosystems. It provides
a key tool to assist in assessing achievement of management
goals and water quality objectives.
Oxley Creek Waterwatch has developed a biological assessment
program which involves the collection in the field of fish
and macroinvertebrates and the visual assessment of creek
habitat. With the assistance of Dr Ngaire Phillips, Oxley
Creek Waterwatch has assessed creek life over a number of
wet and dry seasons. Prior to this work, knowledge of the
creek life of Oxley Creek was poor.
Dr Phillips’ statistical analysis of the data collected
by Oxley Creek Waterwatch revealed the link between creek
bank (riparian) vegetation and the abundance of creek life.
Degraded riparian vegetation coincides with low levels of
creek life.
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