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Burnett Mary NRM Region’s
State of the Estuarine
Environment report
David Scheltinga, Andrew Moss, Sue Sargent,
Jenna Hill, Derani Sullivan, EPA techs, Plus
many more
Stressor based approach
Stressors:
What are key
stressors
impacting on
estuaries?
Aquatic sediments
Bacteria/pathogens
Biota removal/disturbance
Freshwater flow regime
Habitat removal/disturbance
Hydrodynamics
Litter
Nutrients
Organic matter
Pest (plant, animal) species
pH
Toxicants
Habitat removal/disturbance
Biota removal/disturbance
Litter
Steve Posselt
Pests
Human activity
Direct pressure
Pressure mediating factors
– e.g. Farm BMP, zero till,
trash blanketing
Framework logic – Cause and Effect
% ground
e.g.cover
Stressor ‘sediments’
Sediment load
Phys-chem state
Biological impact
Estuary’s ‘intrinsic’
mediating factors –
e.g. its length and
tidal range
Turbidity
% cover seagrass
Conceptual models to
support indicators
Examples of indicators
Stressor
Human activity pressure
indicators
Aquatic
Catchment land-use
sediments % of catchment cleared
% length of river system with
no riparian vegetation
Presence of point sources
Boating activity
Bacteria/
Sewage treatment plant
pathogens discharge
Sewage overflow events
% catchment under intensive
animal production
Number of septics within
catchment
Biota
Commercial bait collection
removal/
Commercial trawler usage
disturbance Boats moorings
Boating activity
Recreational usage index
Estuary population size
Recreational fishers usage
Direct pressure
indicators
Monitored or
modelled sediment
loads entering the
estuary (total diffuse
and point sources)
Phys-chem state
indicators
Secchi depth
Turbidity
Biological impact
indicators
Change in seagrass
extent
% cover of seagrass
Change in mangrove
extent
Intestinal enterococci
counts
Number of mass
mortality events caused
by pathogens
Fish, crab and prawn
abundance
Assessment and Scoring
Overall estuary
health score
Overall estuary
risk score
Comparison against thresholds
Score adjusted
Stressor ranking
Stressor Risk
score
Stressor 1
Condition score
Stressor 2
Condition score
Comparison against thresholds
Score boost
Indicator weighting
Vulnerability
score
X
Pressure indicator
score
Condition indicator
1 score
Comparison against thresholds
Raw data
Raw data
Condition indicator
2 score
Benefits of the framework
• Numerous benefits for decision support
• Allows the identification of the key pressures
in the area
– which can help identify what the key condition
indicators to monitor are (i.e. only monitor relevant
indicators)
– which can then be the targets of management
actions
• Allows justification for why and where did
management work
Benefits of the framework
• Is relatively cheap and easy to perform ‘risk’
analysis
• Pressure indicators will respond to
management action much earlier than
condition indicators
• Identify the causes and effects, making it
easier to identify appropriate management
actions
• Can be used for various reporting needs
• Report on dependability and confidence
9 new estuaries
monitored by BMRG
Sites
10 additional sites
monitored by EPA
and funded by BMRG
What is being monitored
• 37 condition, 51 pressure and 7 vulnerability
indicators
• Started April 2007
• Currently have information on about 75%
• Finish May 2008 and report soon after
catchment land-use
pest species in adjoining areas
stormwater
commercial and recreational fisher usage
port/harbour/marina and boating activity
Unsealed road density
Photo NRW
Google Earth
Riparian vegetation
Tidal barrage; estuary loss
impoundment density
Photo SEQ
Catchments
Photo NRW
Clear runoff
Turbid runoff
Experiment at Mt Mort near Ipswich
Results from a 54mm storm
Treatment
87% cover
69% cover 6% cover
Total runoff from
storm (mm)
1.5
% rain that runoff
3
26
70
Soil loss (t/ha)
0.03
0.3
22
Depth soil lost
(mm)
0.002
0.02
1.7
Sediment
concentration (g/L)
1.5
1.9
63
N loss (kg/ha)
0.14
1.9
15.3
P loss (kg/ha)
0.02
0.26
4.3
Finlayson and Silburn, 1996
14
38
Matching
stocking rates
to pasture
availability is
the key to
effective
management
in grazing
lands
Photo ACTFR
mangrove extent
Google Earth
saltmarsh extent
seagrass extent, % cover
and
% epiphytic growth
bacteria counts
toxicants in sediments
toxicants in water
chlorophyll-a and nutrients
pH, DO, turbidity
Presence of litter
Accumulation rate of litter
Neuse River, USA http://switchstudio.com/waterkeeper
/issues/Spring%2007/neuse.html
mass mortality events
red-spot disease
Photo QASSIT, NRW
Example – vulnerability
• natural water clarity
• flushing rate
• presence of conservation areas
• tidal range
• resuspension rate
Mary River
Kauri Creek
DRAFT
DRAFT
DRAFT
DRAFT
Summary
• A way forward is being developed (slowly) for
integrating agency, local authority and community
monitoring data
• Advantages to all parties by working cooperatively –
sharing resources, knowledge, methods, QA, etc.
• Both able to make good use of the data (provided that
the quality is good)
– to compare with guidelines
– data used to establish a baseline for estuaries
• QA important if data is to be of real use – the direct
involvement of the EPA helps to ensure this
• Get outcomes that are useful to all (improved health)
• Provided that all parties do their bit properly and
comprehensively
Contact
David Scheltinga
EPA
[email protected]
(07) 3896 9242