A brief pictorial history of Noosa Main Beach and Estuary reviewing coastal management from first nations through first settlement to current day - with a brief overview of coastal management theory.
Sources include Nancy Cato's Noosa Story and other publications featured in slides.
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The Shifting Sands of Noosa
1. The Shifting Sands of
Noosa
Estuaries & Coasts
Did we manage in the past?
Are we managing now?
Can we manage in the future? 1
2. OUTLINE
Geologic and historic timeline of Noosa
coasts and estuaries
Geo 100 – Understanding coastal and
estuary processes
The past and present of coastal
‘management’ interventions
The future challenges for Noosa coasts
and estuaries
2
5. 20 000 years Over the Sea
5
The oldest dated evidence of occupation in South East
Queensland comes from Stradbroke Island 20,560 +/-250
BP – Pleistocene, when this area was part of the mainland;
7. Aboriginal Use of Coast
7
There is evidence of aboriginal
occupation in the Great Sandy Region
for at least the past 5,500 years.
Transformed around 3000 BP with
climate induced changes in rainforest
resources
Demographic and technological
changes occurring approximately 1500
BP may have been triggered by key
areas such as SEQ
Semi-sedentary aboriginal villages and
huge gatherings of several thousand of
people being supported by migratory
fish runs
15. 15
1940s ORIGINAL NOOSA SPIT
Large sand bars shifted up
and down the coast with the
channel.
Main Beach, Noosa Woods
and Noosa Spit in the
1940s show a very different
landscape to that of today.
The promontory of the Spit
was less than half its
current size.
32. Estuaries
Include deltas, tidal marshes and mangrove swamps
Partially enclosed
Mixing of fresh and salt water
Highly productive
Strongly affected by tides and flows from catchments
MacroalgaeGroundwater
Mangroves
Seagrass
Meadow
Phytoplankton
Terrestrial
Vegetation
Salt marsh
Estuary conceptual model - http://www.ozcoasts.gov.au
36. Coastal Dune Systems
Dunes are part of the active beach system that helps
protect against storm events
Cross-section of a
sandy beach showing
the significant
difference in the
volume of sediment
eroded in high-
magnitude storms
(1:100 year)
compared to seasonal
erosional events.
http://www.ozcoasts.gov.au
45. Dunes and Beach Erosion
Clearing and development
on coastal dunes
Coastal engineering –
groynes, retaining walls
interrupt natural sediment
transport
Loss dune vegetation
results in beach erosion
and loss of property
45
49. The First Rock Wall
Following cyclones in 1967–68, panicked
beachfront property owners began dumping
rock in front of their properties to hold back the
sea. With approval from the state
government’s Department of Harbours and
Marine, Noosa Council constructed a boulder
wall that permanently fixed the shape of the
bay. The wall broke up during subsequent
storms, thus requiring further work. 49
52. 3. Hays Island becomes Noosa Sound.
52
In 1972, Noosa Council
approved an application to
develop Hays Island as a
canal estate. It was habitat for
inestimable numbers of crabs,
birds and reptiles, and its
mangroves provided essential
shelter for fish fingerlings.
The 144-acre development, called Noosa
Sound, stretched from the bridge behind what
is now the Sheraton Resort all the way to
Munna Point.
53. The Sound
Sand was pumped from
the river to raise the
land by one metre and
natural channels were
widened to create
artificial waterways.
53
Following the cyclones of 1974 and 1976,
there was panic about the possible
consequences of a cyclonic event combined
with high tide and river surge. At the time some
of Noosa Sound was in direct line of sight to
the open ocean.
59. The Spit Extended
In 1977 a scheme for the
“protection” of Hays Island
and “restoration” of Noosa
Beach surfaced, jointly
funded by state and local
governments plus Noosa
Sound’s developers. The
design provided for a
relocation of the river
mouth further northwards
59
The Spit Scheme was
completed in December
1978. Significant erosion
appeared at the southern
end of Noosa Main Beach
only a few months later.
70. Sand Pumping
Trials with a submerged sand-pump began in
December 2004 while plans were developed for
a permanent installation.
70
71. Pumping Statistics
Approx 1000 cubic metres per day ( 100
truckloads)
Cost $3.50per cu m ( alternate $15-20 cu
m) (Hastings Street Business levey)
Aims to achieve a 1:7 gradient to dissipate
wave energy
On average only need to pump a couple of
times a year , if profile is OK no need to
pump
71
76. Doggy Beach Reclaimed
Even though the hydrologists had not modelled their
proposal beyond the Noosa Spit area, council chose to
proceed with the project at an estimated total cost of
$3.6 million. Due to concerns about stream power
some of the planned submerged geotextile bags were
substituted with rocks.
76
82. Ocean acidification
Tracking an Ocean of Carbon FEB 2012 4:02min
Acid Test: The Global Challenge of Ocean Acidification 21:35min
82
83. OCEAN ACIDIFICATION
the name given to the ongoing decrease in the pH and
increase in acidity of the Earth's oceans, caused by the
uptake of anthropogenic carbon dioxide (CO2) from
the atmosphere.
About a quarter of the carbon dioxide in the atmosphere
goes into the oceans, where it forms carbonic acid.
As the amount of carbon has risen in the atmosphere there
has been a corresponding rise of carbon going into the
ocean
Between 1751 and 1994 surface ocean pH is estimated to
have decreased from approximately 8.25 to
8.14, representing an increase of almost 30% in "acidity"
(H+ ion concentration) in the world's oceans.
This ongoing acidification of the oceans poses a threat to the
food chains connected with the oceans. 83
84. Coral Reefs
A rock like accumulation of
carbonates secreted by corals and
algae along marine shorelines
Largest variety of species of marine
life in a very tiny area
Produce more living biomass than
any other marine ecosystem
Remove CO2
Protect against wave action
Very important to fisheries
and tourism industries
Problems: very slow growing
and easily damaged
Great Barrier Reef
GBRMPA
87. 1990 - Baseline Summer
Maximum Temperature
2100 – Summer
Maximum Temperature A2
88. CHANGES TO CONDITIONS IN
SEQ
Most Likely Scenario
More frequent and severe droughts.
Increased intensity of storm events
3-5% decrease in rainfall
Increased flooding and erosion