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13. Existing DMP (2006)
Noosaville Dredge Management Plan
Prepared by Noosa Council Environmental
Services and Works
May 2006
Amended November 2006
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1.0 Site Based Management Plan (SBMP)
1.1 Issue
Currents, tides and boat wash are eroding sections of the Noosaville foreshore. These
areas are State Land under trusteeship of Noosa Council and provide valuable
recreational opportunities for tourists and the general public. While erosion is a
natural event, several sections of the foreshore are now eroding, threatening Council
infrastructure and diminishing recreational values. The Noosaville foreshore under the
Noosa Plan is designated Coastal Protection , Open Space Conservation and Open
Space Recreation . Unstable embankments present a risk for people using these public
open space areas. Some sections of Coastal Protection Zone are quite narrow with
insufficient buffer to allow natural processes of erosion and reclamation to proceed. It
is Noosa Council s intention to protect sections of the foreshore with sand
nourishment works. (See site areas table 1. p. 5)
Under the State Coastal Management Plan 2001 dredging activities within coastal
waters will be undertaken so as to maintain the ability of the site or adjoining land to
function as a barrier protecting from coastal waters, maintain beach or foreshore
stability, but also maintain water quality and coastal habitats.
Noosa Council has an approved Development Application IPDC00067404A3 for
Noosaville Beach Nourishment by dredging, but requires an ERA-dredging license to
undertake dredging works.
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1.2 Environmental Values
Noosa is located on the northern end of the Sunshine Coast and in proximity to World
Heritage Fraser Island and the Great Sandy National Park. The Noosa community and
visitors enjoy clean air in a semi-natural environment.
The Noosa River lakes and adjacent wetlands are one of few such wetland complexes
on the Australian east coast (DEH 2006). The State Coastal Management Plan
describes areas the Noosa River as an area of state significance having significant
coastal wetlands. The Noosa River lakes and adjacent wetlands are one of few such
wetland complexes on the Australian east coast.
The Noosa River Plan 2004 states the river is a relatively un-modified river system
with particularly high environmental and scenic values, and a much sought after
recreation, tourist, and fisheries resources that makes a substantial contribution to the
local economy . The Vegetation of Noosa Shire (NSC 2003) describes mangrove and
saline communities as having immense value to the productivity of these estuaries
and the long term stability of the coastal systems where they are found . Seagrass
stabilises benthic substrate and provides nursery grounds for juvenile seafood species.
Seagrass and mangroves also act as a water purifiers filtering, storing and releasing
nutrients, and slowing water currents to trap suspended sediment. Littoral sandy
foreshore areas provide food and habitat for a number of animals including fish,
crustaceans and molluscs. Fringing vegetation provides leaf detritus, falling logs and
tree roots for benthic invertebrates and larger fish species. Macroalgae, bacteria and
molluscs attach to firm substrate in the littoral zone such as logs, tree roots and stone.
Wetland areas provide valuable roosting and feeding areas for migratory birds and
although the Noosa River is not declared under the Ramsar Wetland Treaty, still
provide important migratory habitat for these species. The Noosa Community and
visitors enjoy a relatively quiet and relaxed atmosphere along the shores of
Noosaville, providing opportunity for recreation, dining and accommodation. The
Noosa River is one of the best rated rivers in SE Qld and the lower estuary has an A-
minus water quality rating.
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1.3 Environmental Objectives
The Noosa River Plan 2004 has identified a number of environmental outcomes for
bed and bank habitat and ecosystem health.
a. Aquatic and terrestrial flora and fauna and their habitats, and riparian
ecosystems are protected from any potential adverse impacts resulting from
development and activities in the river system or on tidal lands.
b. Bank erosion and sediment loadings are not increased or accelerated as a result
of development or activities in the river system or on tidal lands.
c. Dredging of sand from within the river system, only occurs where
i. there is a clear demonstrated public benefit; and
ii. no feasible and prudent alternatives are available; and
iii. it can be demonstrated that the intrinsic values and resources of the river
system can be sustainably managed and protected, including water quality,
fisheries resources and bed and bank habitats.
d. The area of riverfront land held in conservation tenure is preserved, and
increased where possible, to afford protection to riparian ecosystems and to
maintain or enhance water quality.
The EPA has Environmental Policies for Water, Air, Noise and Waste. For example
Environmental Protection (Water) Policy 1997 identifies the Lower Noosa River
Estuary as having high ecological value (level 1) and the importance of maintaining
habitat, biota, flow and riparian areas. The Noosa River Plan aims to reduce noise
levels through boating speed limits and constraints on jet-ski operations. This Plan
also has key strategies to limit waste contamination of the waterway from stormwater
and vessels.
Objectives, parameters and controls for water, air, noise and waste management are
addressed in section 3, 4, 5 & 6 of this report.
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1.4 Environmental Commitment
Environmental excellence and sustainability is a key principle of Noosa Council s
commitment to the environment. Council is committed to its excellent record in
environmental sustainability through its Integrated Environmental Management
System (IEMS). This includes management of its vehicle and vessel fleet to meet
sustainability goals, regular water quality monitoring to ensure that the Noosa River
maintains it s A-minus rating, monitoring of noise emissions and complaints by
Councils Health Department and wise environmental management of waste.
Environmental values, objectives, monitoring and controls for air, water, noise and
waste are identified in sections 3 to 6 of this report.
1.5 Management Plan
1.51 Site details
The worst sections of embankment erosion along the Noosaville foreshore were
identified as needing sand nourishment. There are six areas considered to be a high
priority for beach nourishment because of public risk and threats to Council
infrastructure. Design plans for the six areas originally identified are attached. The
areas are tabled below:
Table 1. Proposed beach Nourishment Area 1-6
Area Location Issue Photo
1 Munna Timber stairs
Point leading from the
caravan park to
the beach are
now exposed
ands are at risk of
collapse.
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2 T-Boats Retaining wall is
being
undermined and
at risk of
collapse.
3 Boat ramp Retaining wall is
to O-Boats being
undermined and
at risk of
collapse.
4 Lions Park Concrete No photo
pathway exposed
on rivers edge.
5 Yacht Club Severe erosion of
bank near yacht
club jetty.
6 Hilton Erosion of
Esplanade riverbank
reducing buffer
and undermining
access to jetties.
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The EPA has approved a Development Application for these works. Under the
approval Area 4 is not critical and is no longer included in this application and Area 6
is now reduced.
1.52 Measures to limit environmental harm
Air, noise and water quality will be monitored as stated in section 3, 4, 5 and 6 of this
report. If parameters exceed objectives, dredge operations will cease until the issue is
rectified and operations can comply with standards. Details of waste management are
provided in section 5 of this report. No waste will be created at either of the
Noosaville dredge sites recommended in this document.
Dredging will not occur in areas of sensitive habitat such as seagrass. Dynamic tidal
water currents coupled with the boat wash effects, coming from adjacent boating
channel, can effect the stability of the substrate, minimizing recruitment of seagrass
meadows (Nybakken 1997, Waycott et.al. 2004). Historical EPA, EHMP and
Seagrass-Watch records since 2002 show no seagrass recruitment in this area at any
time.
Samples of substrate indicated no meio or microfauna present at the dredge sites.
Changes in sediments community structure occur through either physical or biological
factors, or a combination of the two (Nybakken 1997). As stated there are no visible
biological factors evident in this area. Reasons for this could be due to bottom
sediment being regularly disturbed preventing the establishment of polychetes and
mobile crustaceans, which prefer deeper zones of stable sediment. Harsh subtidal
habitats minimize the holding capacity of primary producers that reduce complex food
web structures. Limiting availability for grazers, filter feeders, scavengers or
predators to inhabit the area (Nybakken 1997).
At this site physical factors seem to be controlling community structure of the
benthos. A passage of strong (tidal) current runs along each sand bank. This has been
determined as the primary physical factor, causing large surging motion throughout
the water strata, greatly affecting stability of the substrate. This reduction in stability
is likely to reduce the amount of faunal animals, creating an area that is generally
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without topographic feature diversity (Nybakken 1997). At this site this denuded area
extends for another 100 meters. Interruptions in topographic structure has created an
exposed sand bank at lower tides (<0.50m) which is used as a roosting sites for birds
East of site two (see Figure 1).
The closest predatory inhabitance is represented by nesting site in the river that is
more than 600mts away to the east (represented on the Island in Figure 1). Avian
experts documented on the 5th Nov. 06 that two nests where evident, one of which
was a Pied Oystercatcher (Haematopus fuliginosus)(Simpson & Day 1999).
Figure 1. Site One and Two, with distances shown to all environmentally
significant aspects.
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1.53 Release limits for water quality
Release limits will be monitored through water quality testing and controls initiated if
parameters are exceeded as stated in section 6.
1.54 Monitoring Program
Table 2 below shows Council s monitoring program.
Monitoring Action
Complaints regarding sediment plumes Complete customer request/action form
(example attached), investigate & report
Water quality Turbidity, Suspended Solids, pH
See section 6.2 & 6.3 for details
Noise complaints Complete customer request/action form
(example attached), investigate & report
Emergency and incidents Complete customer request/action form
(example attached), investigate & report
In 1998 Dr. Greg Skilleter (Department of Zoology-Queensland University)
undertook a habitat monitoring program for dredging of the Noosa River estuary for
the beach nourishment of Noosa Main Beach. The results of this work are available on
request.
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1.55 Emergency response and contingency plans
A risk management matrix is shown in table 3 below.
Risk Trigger Action
Acid sulphate PH monitoring Assess area prior to dredging and exclude from
exposure and dredging if ASS soils occurs within the site.
observation Proceed in areas with adjusted dredge depth.
Excess Turbidity Cease dredging, modify dredge operations to
turbidity monitoring reduce turbidity
Excess S.S. Cease dredging, modify dredge operations to
suspended monitoring reduce S.S
solids
Fuel spill Fuel spill As per Oil Spill Contingency Response Plan.
report
Seagrass Observation by Inspect area prior to dredging and exclude from
damage Council officer dredging if seagrass occurs within site.
and Seagrass
monitoring
Rep.
1.56 Education & training
Dredge operators and relevant Council Staff are to be provided with education and
training on environmental issues of air, noise, water and waste as indicated in this
document.
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1.57 Environmental management reports
Notification to EPA will be provided 40 days prior to dredge works. The notification
will include:
Location and quantities
Timetable of works
Depth of water and bottom topography
Current velocities, tidal movements and dispersal of sediments
Sampling program
Acid sulphate investigations
Particle type & size
Contingency plans
Contact details
Potential impacts
Information permits and conditions from other authorities
Management techniques to environmental harm
Weekly reports on the dredge operations will be kept by Council Works Department
at Pelican Street, Tewantin and be made available to EPA if required. The reports will
be kept for five years and annual summaries provided to EPA. The report will address
sand dredging volumes, results of water, noise, air and waste monitoring. A sample
weekly report form is shown attached.
2.0 Activity specific information
2.1 Description of processes
2.11 Plant and machinery
The dredge operator will be contracted as per Local Government procurement
guidelines. Broadwater Dredging have expressed an interest in the dredging works
and attached are details of the plant and machinery specifications.
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2.12 Quantity of materials
Beach nourishment for the Noosaville foreshore project will require < 5000 tonnes per
year to complete the four approved areas. Approximately <2000 tonnes of sand, in
total, is required to be dredged from sites 1 and 2. There will be no waste released,
stored, transferred or disposed of into the environment. Sand materials will be
deposited on beach riverbed areas as per NRM Soil Management Guidelines. Due to
the lack of pyritic fines in the substrate of the selected dredge areas, no redeposition
or movement of any waste products will be performed (refer to 7.1 of this document).
2.2 Scale location plan
See location plans attached in Figure 1.
2.3 Dredge and borrow areas
The eight areas identified contain both the beach nourishment area and associated
sand resource areas. The purpose of dredging is only to replenish sand on river
beaches and protect Council infrastructure. No dredged sand will be removed off site.
There will be no contamination to stormwater drains or runoff from cleaning of
equipment, and no release of contaminant to any land areas. Dredge areas have been
selected adjacent to one another within the main tidal flow area of the river. Dredging
of the left side of the riverbank may cause currents to erode or deposit sediment on the
adjacent bank this is due to high dynamic characteristics with intense tidal factors
playing a commanding role on the river meandering process. Selection of banks
adjacent to one another is considered as effective way of confining effects that could
impact other areas of the river system (Hey, 1997).
River equilibrium is generally determined by the controlling factors that cause a
displacement of the equilibrium in a direction that will tend to absorb the effect of the
change. The controlling factors in this system are width, depth, velocity of the tidal
flow, slope, discharge, size of sediment, concentration of sediment and roughness of
the channel (Hey, 1997). None of these factors will be affected as a result through the
extraction of sediment at these sites. This area of the river has a steady state in which
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there is a continuous inflow and output of materials, in which the form or character of
the system remains unchanged.
Processes of stream channel scour and or deposition will occur in a natural stable
channel, but over time, if this leads to degradation or aggradation, respectively, then
the stream would not be stable (Hey, 1997). Understanding of this has been taken into
consideration, when selecting the site on a sand bank in the river rather than along the
sides of the riverbank. This will allow the preservation of the sand along the riverbank
in this area.
2.4 Operational & maintenance plans
Noosa Council operates an Asset Management and Risk Management Program for
monitoring and maintaining the Noosaville foreshore. Responsible parties are
identified below table 4. First contact officers for this project are highlighted in bold.
Name Area of Responsibility Contact Number
Operating Authority Noosa Council 5449 5200
Alan Sheridan Director-Works 5449 5222
Doug Reynolds Manager-Works Operations 5449 5255
Fred Spinks Works Superintendent 0410512501
David Shing Coastal Maint. Foreman 0410512503
Greg Kentwell Dredge Contractor 0417762553
David Baker Noise Control 54495332
David Heerey Water Quality Testing 54473333
Boating & Fisheries 54497555
Kris Boody Project Officer 0437425901
2.5 Site rehabilitation
No site rehabilitation is necessary because sand will be deposited for beach
nourishment purposes in the tidal zone.
2.6 Erosion protection and revegetation practices
The purpose of the beach nourishment by dredging is to protect erosion buffers and no
revegetation will be required.
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3.0 Air
3.1 Environmental values of air to be protected
The Noosa Community and visitors enjoy are semi-natural environment surrounded
by National Park, beaches, and waterways. Noosa's natural features enable a high
standard of air quality.
3.2 Air quality objectives
The EPA s Environmental Protection (Air) Policy 1997 is designed to protect
Queensland Air. There will be no wind blown dust from the dredge activities, and wet
sand will be used for beach nourishment. Emissions from dredge combustion engines
will comply with State emission control standards.
3.3 Emission sources and control measures
The only emission source will be exhaust fumes from dredge machinery, which will
comply with air quality monitoring standards defined under State emission standards
for combustion motors.
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4.0 Noise
4.1 Environmental values of acoustic environment
Noosaville is an idyllic township located alongside the Noosa River. Its scenic
backdrop provides a peaceful and relaxing are for residents and recreational goers
along the parks and foreshores. Noise is generated from vehicles and boats, but the
area is not considered a high traffic area.
4.2 Acoustic objectives
Noosa Council has an environmental objective of limiting noise emissions to EPA
Environmental Protection (Noise) Policy 1997 standards as in table 4 below.
Noise Limits at a Noise Sensitive Place
Time Periods Noise level at a Noise Sensitive Place
Measured as the Adjusted Maximum
Sound Pressure level
Monday to Friday 7 am 6 pm Background noise level plus 5 dB(A)
Saturday 7 am-12 noon
Monday to Saturday 6 am 7 am Background noise level plus 5 dB(A)
Monday to Friday 6 pm-10 pm
Saturday 12 noon-6 pm
All other times and public holidays Background noise level plus 3
Noise Limits at a Commercial Place
Time Period Noise levels at a Commercial Place
measured as the adjusted Maximum
Sound Pressure level
Monday to Friday 7 am-6 pm Background noise level plus 10 dB(A)
Saturday 7am-12 noon
Monday to Friday 6 am-7 am Background noise level plus 10 dB(A)
Monday to Friday 6 pm-10 pm
Saturday 12 noon-6 pm
All other times and public holidays Background noise level plus 8 dB(A)
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4.3 Noise sources and control measures
The dredge combustion motor that drives the main pump will be the main source of
noise emission. Noise complaints will be monitored and if noise acoustics exceed the
EPA s Environmental Protection (Noise) Policy dredge operations will be stopped
and exhaust baffle systems modified to control noise. Businesses and residents likely
to be affected by the noise of the dredge operations will be notified beforehand of
dredge operations.
4.4 Sensitive areas
Restaurants, public parks and beach areas are identified as the most sensitive areas,
but given the small and localised scale of the operations, this is not considered a
concern .
4.5 Operating times
Dredge will operate 5 days per week from 7am-6pm, which falls well within the
parameters of the EPP (Noise) Guidelines.
5.0 Waste
5.1 Management and disposal of waste
There will be no waste released, stored, transferred or disposed into the environment.
Sand materials will be deposited on beach riverbed areas as per NRM Soil
Management Guidelines. Due to the lack of pyritic fines in the substrate, at the
selected dredge areas, no redeposition or movement of any waste products will be
performed (refer to 7.1 of this document).
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6.0 Water
6.1 Environmental values
The Lower Noosa River has several identified Environmental Values (EVs) under the
EPA s Environmental Protection (Water) Policy 1997. These are aquatic ecosystems,
human consumption value, primary and secondary recreation, visual recreation
cultural and spiritual values and seagrass meadows.
6.2 Water quality objectives
EPA in its Environmental Protection (Water) Policy 1997 defines Water Quality
Objectives (WQO) to 20th, 50th and 80th percentiles for the Noosa River and these are
listed below:
Turbidity: 1-2-4 NTU
Suspended solids: 15-15-15 mg/L
Chlorophyll a: 0.8-1.2-1.8 g/L
Total Nitrogen: 150-180-240 /L
Oxidised N: 2-3-6 /L
Ammonium N: 4-8-15 g/L
Organic N: 140-160-220 g/L
Total phosphorus: 9-12-15 /L
Filterable reactive phosphorus (FRP): 2-2-2 /L
Dissolved oxygen: 90-95-105% saturation
PH: 8.0-8.2-8.4
Secchi depth: 1.8-2.2-2.8
Specific water quality objectives as related to dredging are in table 5 below:
Quality Characteristics Limit
Suspended solids Not more than 10 mg/L, or 10 percent
above background, whichever is the
greater.
Turbidity (NTU) Not more than 2 NTU, or 10 % above
background, whichever is the greater.
pH Within the range of 7.0 to 8.5 pH units
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There will be no release of petroleum products from any vessel involved with the
operations. There will be no release of contaminants that could cause environmental
harm such as organisms, oil, grease, scum and litter. There will be no discoloration to
the receiving waters outside the 100m zones.
6.3 Environmental measures and monitoring
Water quality testing will be undertaken for Suspended Solids, Turbidity and pH at
the frequencies specified below Table 6.
Monitoring Activity Frequency
Suspended Solids Weekly
Turbidity Daily
pH Daily
The Noosa Council chemist will undertake water quality testing with instruments and
devices appropriately operated and maintained. Background water will be tested
between 130-150 metres up current from release point and 100-120 metres down
current.
6.4 Sediment, erosion control and spoil management
No release of contaminants into the water will result when sediments are disturbed
during extraction and placement of dredged beach sand from these particular sites.
This will eliminate the need for fines to be deposited through Strategic Reburial as
per NRM conditions and no dredge material will be released into any other location.
All practical measures will be employed to reduce levels of turbidity. Four months
after cessation of the dredging, Council will provide a report on suspended solids and
turbidity and any environmental issues that may have occurred from the activity.
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7.0 Acid Sulphate Soils
Noosa Council will follow the best practice environmental management, as outlined
in NRM s Soil Management Guidelines, to avoid environmental harm. Noosa Council
will manage the dredge operations based on the following Soil Management
Guideline principles:
1. ASS will be avoided by shallow dredging to a maximum depth of -2.5 metres
AHD.
2. If ASS is present hydraulic separation of sulphides and strategic reburial will
be undertaken to ensure that any pyrites are kept in anaerobic conditions.
3. There will be no stockpiling of untreated ASS above the permanent
groundwater table.
4. Selection of a dredge site will be considered only after laboratory analysis of
ASS has been completed.
7.1 PASS Testing and Operations
Soil Surveys Engineering P/L tested areas located upstream from Munna Point along
Gympie road, Noosaville (Figure 1) for acid sulphate soils (ASS) in November 2006.
Four boreholes were drilled 50+ metres from the riverbank and to a depth of 4 metres
finishing, at times, 2 metres below the proposed dredge depth (Soil Surveys 2006).
Vibracore drilling method provided a continuous sample of the subsurface soil, which
is retained within a plastic sleeve. Samples were tested at 250mm depth intervals in
each of the boreholes (a total of 56 samples) for potential acid sulphate soils (PASS)
analysis. Each test sample was assessed for both the field pH (pHF) and oxidised pH
(pHFOX) of the material. A pHFOX value of less than 3 indicates a strong likelihood of
the soils being PASS. The three (3) samples representing the depth interval 3.25m to
4.00m (borehole termination depth) in borehole BH2 returned pHFOX values of 2.4,
suggesting the presence of PASS material. The pHFOX values of all remaining
samples were between 3.2 and 6.8. (Soil Survey 2006).
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Representative samples, at 500mm depth intervals in each of the boreholes (a total of
28 samples), were assessed by Chromium Reducible Sulfur (CRS) and Total Actual
Acidity (TAA) tests. The CRS test provides data on sulfidic acids, without influence
from organic acids and quantifies the oxidisable sulphur present in the soil. The TAA
measures the existing acidity of the soil prior to the oxidation of any sulfidic material
(Soil Survey 2006).
The CRS test results ranged from 0.02 to 0.13 %S. Of the 28 samples tested, 17
samples returned CRS results equal to or in excess of the QASSIT Action Level of
Oxidisable Sulfur of 0.03%S (Queensland Acid Sulfate Soils Investigation Team
(QASSIT) Guidelines for Sampling and Analysis of Lowland Acid Sulphate Soils
(ASS) in Queensland (October, 1998)). Most of these samples containing elevated
levels of oxidisable sulphur occurred in boreholes BH1 (four (4) samples) and BH2
(seven (7) samples), with three (3) samples present in each of boreholes BH3 and
BH4. According to the QASSIT Guidelines, soils containing oxidisable sulphur, at
0.03%, require treatment with lime in order to neutralise the acid that could
potentially be produced by the soil. These 17 samples were subjected to further
analysis (Acid Neutralising Capacity testing) to determine the amount of carbonate
material available in the sample to act as a self-buffering agent (Soil Survey 2006).
The TAA test results show that there was no actual acid present in the treated
samples with zero value reported in all cases i.e.28 No. test, as shown on the
laboratory test certificate (Soil Survey 2006).
Acid neutralizing Capacity (ANC) is a measure of the soil s inherent ability to buffer
acidity and thereby resist the lowering of the soil pH. Acid neutralizing Capacity
(ANC) was carried out on the seventeen (17) samples described above. These
samples returned calcium carbonate equivalent (CaCO3 Eq.) values between 0.55%
and 1.51% (Soil Survey 2006).
These results indicate that there is ample self-buffering capacity present in the
soils to effectively neutralise any acid that could potentially be produced. Therefore
we recommend that no lime treatment would be required on the samples tested
during this investigation (Soil Survey 2006).
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7.2 Risk Assessment & Soil management Guidelines
It is unlikely that acid sulphate soils will be an issue with this project because:
There will be only shallow dredging of recent sand banks (<2.5 metres AHD)
Only small volumes of sand are to be dredged per year (<5000 tons)
Although re-suspension of deposited fines may occur, absence of pyritic fines
at this site, reduce the likelihood of contamination of the water column (Soil
Survey 2006).
The areas concerned have a high tidal exchange and any acidity will be
quickly neutralised by seawater and/or the self-buffering capacity present
within the substrate that is high in calcium carbonate (CaCO3) mater (Soil
Survey 2006).
Dredge operations will be water quality monitored daily and if pH levels
exceed WQO s then operations will cease.
Risks of ASS are identified in table 6 below.
Soil Method Issues ASS Risk
Dredged Sand from Hydraulic None Low
site separation of fines
Imported sand Truck Cost, access and low Low
sand quality
Imported sand from Sand barged from Navigation, public Low
lower estuary areas with no Acid concerns, expense
Sulphates e.g. use
existing ERA at
river entrance or
sand banks off
Munna Point
7.3 Specific Quantities
Of the <5000 tonnes of dredged material that has been stipulated on the ERA, it is
estimated that <2000 tonnes (approximately) will need to be dredged for
replenishment purposes of stated areas that have been defined in 1.51 of this
document.
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References:
A guide to Tropical Seagrasses of the Indo-West Pacific. 2004.
Michelle Waycott, Kathryn McMahon, Jane Mellors, Ainsley Calladine and Diana
Kleine. James Cook University, Townsville. 72 pages.
Hey, R.D., 1997. Stable River Morphology. Applied Fluvial Geomorphology for
River Engineering and Management. Ed., C.T.Thorne, R.D. Hey and M.D. Newson.
P223-236, John Wiley and Sons.
Nybakken J.W. 1997, Marine Biology: An Ecological Approach. 4th ed. Addison-
Wesley Educational Publishers Inc. USA.
Simpson & Day 1999, The Birds of Australia: A Book of Identification. 6th ed.
Penguin Books Aust.
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