Media
Release
Increased
sediment causes concern
for reef
February 13, 2003
A new study has found evidence that land
based activities in North Queensland may be affecting the water quality
of the Great Barrier Reef (GBR).
The ANU Research School of Earth Sciences
group, led by Professor Malcolm McCulloch in collaboration with the
Australian Institute of Marine Science, has shown that sediment supply
from the Burdekin River to the GBR has increased by a factor of 5 to 10
shortly after European settlement of the catchment in the 1860's.
"The impact on water quality and the
marine environment of increased sediment supply is highly uncertain, but
experience in other parts of the world suggest it should be a cause for
concern," Professor McCulloch said.
The study, published in today's issue of
the international journal Nature, used the chemical composition of
corals that have been growing for more than 250 years to determine
sediment fluxes from the Burdekin River since 1750.
This coral record shows that before the
1860's, suspended sediment from river floods reached the inner reef area
only occasionally. Since then, there has been a frequent influx of
sediment with each significant flood event.
These results show that past and present
land use practices have led to soil loss, which has increased the amount
of sediment entering the river and ultimately the ocean. An increase in
sediment flux is thought to impact the marine environment by increasing
the supply of nutrients, which has been linked with changes in coral
growth and a shift from coral to algae dominated reefs.
"An interesting feature of our
research is that we can also see the influence of drought. After a
prolonged period with limited rainfall, the amount of sediment carried
in the following flood increases significantly," Prof McCulloch
said.
Prof McCulloch is keen to see similar
studies pursued to improve the understanding of the influences of land
based activities on the GBR. "Our study provides a baseline for
pre-European sediment fluxes and a way of monitoring land runoff in the
future. It would be exciting to see other researchers use this result to
investigate further the links between sediment runoff, water quality and
the marine environment."
For media interviews
contact:
Dr. Janice
Lough, AIMS
Telephone: 61 7 47534248
Email: j.lough@aims.gov.au
Dr. David Barnes, AIMS
Telephone: 61 7 47534248
Email: d.barnes@aims.gov.au
Theresa Millard, AIMS Science Communications
Telephone: 61 7 47534250
Mobile 0409 596 271
Fax: 61 7 47716138
Email: t.millard@aims.gov.au
 AIMS home page
web@aims.gov.au
Last updated - February 13, 2003
Copyright ©1996-2003 Australian Institute of Marine Science
URL http://www.aims.gov.au
[ About AIMS ]
[ AIMS research ] [ AIMS facilities
] [ AIMS news ] [ AIMS search ]
[ AIMS publications ] [ Doing business with AIMS ] [ What's new ]
[ Site index ] [ Navigating this
site ] [ Privacy
policy ]
|
