Burnett Mary NRM Region’s Burnett Mary NRM Region’s State of the Estuarine State of the Estuarine Environment reportEnvironment report

David Scheltinga, Andrew Moss, Sue Sargent, Jenna Hill, Derani Sullivan, EPA techs, Plus

many more

Stressor based approachStressors:

Aquatic sedimentsBacteria/pathogens Biota removal/disturbanceFreshwater flow regimeHabitat removal/disturbanceHydrodynamicsLitterNutrientsOrganic matterPest (plant, animal) speciespHToxicants

What are key stressors impacting on estuaries?

Habitat removal/disturbanceHabitat removal/disturbance

Biota removal/disturbanceBiota removal/disturbance

LitterLitter

PestsPestsSteve Posselt

Human activityHuman activity

% ground cover% ground cover

Direct pressureDirect pressure

Sediment loadSediment load

Phys-chem statePhys-chem state

TurbidityTurbidity

Biological impactBiological impact

% cover seagrass% cover seagrass

Pressure mediating factors – e.g. Farm BMP, zero till, trash blanketing

Estuary’s ‘intrinsic’ mediating factors – e.g. its length and

tidal range

Framework logic – Cause and EffectFramework logic – Cause and Effecte.g. Stressor ‘sediments’e.g. Stressor ‘sediments’

Conceptual models to support indicators

Examples of indicators Stressor Human activity pressure

indicatorsDirect pressure indicators

Phys-chem state indicators

Biological impact indicators

Aquatic sediments

Catchment land-use% of catchment cleared% length of river system with no riparian vegetationPresence of point sourcesBoating activity

Monitored or modelled sediment loads entering the estuary (total diffuse and point sources)

Secchi depthTurbidity

Change in seagrass extent% cover of seagrassChange in mangrove extent

Bacteria/ pathogens

Sewage treatment plant dischargeSewage overflow events% catchment under intensive animal productionNumber of septics within catchment

Intestinal enterococci counts

Number of mass mortality events caused by pathogens

Biota removal/ disturbance

Commercial bait collectionCommercial trawler usageBoats mooringsBoating activityRecreational usage indexEstuary population sizeRecreational fishers usage

Fish, crab and prawn abundance

Assessment and Scoring

Condition indicator 2 score

Condition indicator 1 score

Comparison against thresholds

Raw data

Score boost

Indicator weighting

Comparison against thresholds

Overall estuary health score

Stressor 1 Condition score

Stressor 2Condition score

Score adjustedStressor ranking

Comparison against thresholds

Raw data

Overall estuary risk score

Stressor Risk score

Pressure indicator score

Vulnerability score X

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

Sites

9 new estuaries monitored by BMRG10 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

stormwater

pest species in adjoining areas

commercial and recreational fisher usage

port/harbour/marina and boating activity

Unsealed road density Photo NRW

impoundment density

Tidal barrage; estuary loss

Riparian vegetation

Photo SEQ Catchments

Google Earth

Clear runoff Turbid runoffPhoto NRW

Experiment at Mt Mort near IpswichResults from a 54mm storm

Treatment 87% cover 69% cover 6% coverTotal runoff from storm (mm)

1.5 14 38

% 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

Matching stocking rates to pasture availability is the key to effective management in grazing lands

Finlayson and Silburn, 1996

Photo ACTFR

saltmarsh extent

mangrove extent

seagrass extent, % cover and

% epiphytic growth

Google Earth

toxicants in sediments toxicants in water

bacteria counts

pH, DO, turbiditychlorophyll-a and nutrients

Accumulation rate of litter

Presence of litter

red-spot diseasemass mortality events

Photo QASSIT, NRW

Neuse River, USA - http://switchstudio.com/waterkeeper/issues/Spring%2007/neuse.html

Example – vulnerability• natural water clarity• flushing rate• presence of conservation areas• tidal range• resuspension rate

Kauri CreekMary River

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

ContactDavid ScheltingaEPAdavid.scheltinga@epa.qld.gov.au(07) 3896 9242