1. UNDERSTANDING THE WESTERNPORT ENVIRONMENT: identification, effects and management of toxicants
Jackie Myers1, Kathryn Hassell1, Simon Sharp1, Michael Keough1, Vincent Pettigrove1, Rhys Coleman2
1 Centre for Aquatic Pollution Identification & Management (CAPIM), School of Biosciences, University of Melbourne
2 Waterways and Wetlands Research Manager, Melbourne Water

2. Westernport: a unique feature on the Victorian coast
Mudflats
VICTORIA
Melbourne
Rocky reefs
Recreational fishing
Agriculture
Saltmarsh
Shorebird habitat
Seagrass
Open water
Industry
RAMSAR
Urban growth
Marine national parks

3. Lack of research since 1970s Lack of consolidated information about key values, threats and management priorities Need for Strategic Understanding of Western Port Environment (Better Bays & Waterways 2009)

4. Western Port Environment Science Review
Project led by Melbourne Water Funding and support from DSE (DELWP) and P&WP CMA 9 government agencies, 11 researchers (Prof. Michael Keough UoM) Broader stakeholder input e.g. WPCC Review released in March 2012 Research program commenced in 2011 and ongoing

5. Strategic Knowledge Gaps
Priority research needs in Chapter 15 of science review:
• 43 recommendations for research
• 13 high priority research projects

6. Toxicants and their threat to Western Port
What is a Toxicant? “Chemical pollutant that can have toxic effects on biota”1
Toxicant sources
Environments at Risk
toxicants
antifoulants
PAHs
metals
pesticides
hydrocarbons
nutrients
1ANZECC & ARMCANZ (2000) Australian and New Zealand guidelines for fresh and marine water quality.

7. An Initial Screening of Toxicants in Sediments 2011-12
What is the ecological risk from toxicants?
STUDY
• 45 sites within bay, estuaries and freshwater inputs
• Comparison with historical data
Heavy metals, pesticides, organotins, hydrocarbons
KEY FINDINGS
• Toxicant screening found most toxicants appear to be low
• Isolated areas, primarily northern estuaries, recorded elevated herbicides and fungicides
RECOMMENDATION
• investigate if current types and levels, of herbicides are likely to be impacting key habitats in Western Port (seagrass/mangroves)
Report available on Melbourne Water Website

8. Understanding the risks from herbicides 2014-15
What is the spatial and temporal variability in pesticide concentrations?
Does herbicide pollution pose a risk to seagrasses and mangroves?
STUDY
Field monitoring Program
2 sub-catchments – Watsons Creek & Western Contour Drain
Monthly water sampling at fresh, estuarine and marine sites for 1 year
Storm event sampling & a sediment survey
Laboratory Exposure Experiments
Seagrasses Zostera muelleri & Z. nigricaulis
Mangrove Avicennia marina
Herbicides: simazine, prometryn & diuron
Hydrodynamic Modelling
Assessed suspended solids & herbicide fate

9. Understanding the risks from herbicides 2014-15
KEY FINDINGS
• Pesticides were detected in complex mixtures often at elevated concentrations that may pose risk to fauna and flora
• Storm events transported ↑ pesticide concentrations, however concentrations ↓ travelling downstream
• Modelling indicates concentrations pose greatest risk during storms, otherwise movement is localised
• Laboratory exposures indicate herbicides pose:
low-medium risk to early mangrove establishment
medium risk to seagrass health
RECOMMENDATIONS
• Isolate and identify pesticide sources
• Survey and assess for biological impacts
Fresh
Concentration (µg/L)
Bay

10. Understanding the sources of pesticides 2015-16
Where are pesticides coming from?
Is biological impairment occurring in Western Port catchments?
STUDY
24 sites across Watsons Creek & Western Contour Drain
2 sampling rounds: Winter & Spring (2 x 3 week deployment)
113 pesticides and nutrients (NO3, NO4, NH3, PO4)
Land use mapping
Ecotoxicology:
In situ microalgae, shrimp, cotton and leaf bag assays
Field collected amphipods
Fish Health Assessment:
Demersal toadfish, Tetractenos glaber
2 sampling rounds: Winter and Spring (4 estuaries & a reference)
General health & condition plus targeted biomarkers
Looked at biomarkers in each – growth, GST activity, breakdown rates and functional stream health index.

11. Understanding the sources of pesticides 2015-16
KEY FINDINGS
Pesticide and nutrient pollution greatest in the mid to most downstream reaches
Western Contour Drain > pollution than Watsons Creek
Greatest biological impairment observed in mid to lower reaches
Herbicides & fungicides dominant groups detected & originate from agricultural rather than urban land uses
Fish: No one site consistently more affected, general health and cellular alterations warrant further investigation
RECOMMENDATIONS
Assess pesticide pollution in other agriculturally dominated catchments
Assess how pesticide properties & agricultural practices influence transport

12. This research was funded by Melbourne Water and supported by CAPIM
Acknowledgements
Co-authors on aspects: of project: Dave Sharley Hung Vu Sara Long Cathy Cinque Chris O’Neill Field and Laboratory Assistance: Mayumi Allinson Mike Williams Jaclyn Harris Andre Limsowtin Richard Emlet Kallie Townsend
Daniel MacMahon
Kylie Myers
Erin Cummings
Sherrie Chambers
Joel Bowater
Rhianna Boyle
Yaringa Boat Harbour (Robert Kelly)
Kooweerup Boat Club
Mornington Peninsula Youth Enterprises: Bob Couchman
Victorian Marine Science Consortium: Liz Mc Grath, Rod Watson
This research was funded by Melbourne Water and supported by CAPIM