Initial estimate of sediment toxicants beyond estuary mouths in - - PowerPoint PPT Presentation

Initial estimate of sediment toxicants beyond estuary mouths in Western Port Toxicants in sediments: a screening study

Vincent Pettigrove, Simon Sharp & Jackie Myers Centre for Aquatic Pollution Identification and Management (CAPIM)

Key Recommendation from review

Previous Research

Toxicants in sediments

Toxicant “Chemical pollutant that can have toxic effects on biota”1 Heavy metals – above “natural” levels Petroleum Hydrocarbons – also occur naturally Pesticides – synthetic agriculture chemicals Antifoulant paints – tributyltin (historical) Toxicants

1- ANZECC & ARMCANZ (2000) Australian and New Zealand guidelines for fresh and marine water quality. National Water Quality Management Strategy. Australia and New Zealand Environmental and Conservation Council & Agriculture and Research and Management Council of Australia and New Zealand.

Previous reports

Trace metals in Western Port sediments : final report

P.J. Statham

December 1977

Marine Chemistry Unit, Ministry for Conservation

Western Port Bay Inflows – freshwaters and estuaries

1 2 4 3

1 - Rees et al (1998) Toxicants in Western Port sediments. Report to EPA Victoria 2 – Statham (1977) Trace metals in Western Port sediments: final report. Marine chemistry unit, Ministry for Conservation 3 – Hardwick (1998) Waterway assessment for the Western Port catchment: the environmental health of Western Port Peninsula Streams. 4 – Coleman & Pettigrove (2001) Waterway assessment in the Western Port catchment. The health of the Lang Lang River. Melbourne Water

Toxicants in Western Port sediments

Sampling based on previous reports: Heavy metals1,5 Organic pesticides2,5,6 Petroleum hydrocarbons1,5,7 Tributyltin from antifouling paint residues1,4

1 - Rees et al (1998) Toxicants in Western Port sediments. Report to EPA Victoria 2 – Hardwick (1998) Waterway assessment for the Western Port catchment: the environmental health of Western Port Peninsula Streams. 3 – Coleman & Pettigrove (2001) Waterway assessment in the Western Port catchment. The health of the Lang Lang River. Melbourne Water 4 – Daly & Fabris (1993) An environmental study of tributyltin in Victorian waters. EPA Victoria. 5 – CAPIM (2012) Unpublished data 6 – Melbourne Water (2008) Unpublished data 7 – Burns, K. & Smith, J. 1977. Distribution of Petroleum Hydrocarbons in Westernport Bay (Australia): Results of Chronic Low Level Inputs.

Current Toxicant Study

Toxicants in sediments

Study Objectives

1) Assess concentrations of toxicants with guidelines, 2) Determine patterns or possible sources of toxicants, 3) Compare concentrations of toxicants over time.

Study sites

42 Estuarine, freshwater and bay sites sampled during the study

Sampling Methodology

• Sediment grab samples collected by wader and boat
• Filtered (<0.063 mm) to reduce variability
• Analysis:
• Heavy metals,
• Total organic carbon (TOC),
• Total petroleum hydrocarbons (TPHs),
• Grain Size,
• Pesticides
• Tributyltin and organotins (TBT)

42 sites 22 sites 7 sites

Estimating ecological threats from toxicants

Concentrations in sediments were compared to the Interim Sediment Quality Guideline (ISQG) values (low) for1:

• Heavy metals
• Pesticides (Organochlorine only)
• Tributyltin

Proposed sediment quality guidelines for2: Total petroleum hydrocarbons (TPH)

1- ANZECC & ARMCANZ (2000) Australian and New Zealand guidelines for fresh and marine water quality. National Water Quality Management Strategy. Australia and New Zealand Environmental and Conservation Council & Agriculture and Research and Management Council of Australia and New Zealand. 2 – Simpson et al (2010) Revision of the ANZECC/ARMCANZ sediment quality guidelines. CSIRO Land and Water Science Report 08/07.

Research findings

Heavy Metals in Western Port

Low concentrations at all sites: Metalsa:

• Cadmium*
• Chromium*
• Copper*
• Lead*
• Zinc*

compared with ISQG-low values

Metalsa

Heavy Metals: Arsenic

Moderate concentrations at various sites: Arsenic compared with ISQG-low values Slightly higher concentrations than 1997

Heavy Metals: Mercury

Moderate concentrations at various sites: Mercury compared with ISQG-low values Slightly higher concentrations than 1997

Heavy Metals: Nickel

Moderate concentrations at various sites: Nickel compared with ISQG-low values

Heavy Metals: Nickel

Moderate concentrations at various sites: Nickel compared with ISQG-low values No apparent changes in concentrations

Petroleum Hydrocarbons (TPH) in Western Port

Maximum - 133 mg/ kg Proposed threshold concentration1 – 275 mg/ kg

1- Simpson et al (2010) Revision of the ANZECC/ARMCANZ sediment quality guidelines. CSIRO Land and Water Science Report 08/07.

Below threshold (275 mg/ kg)

Petroleum Hydrocarbons (TPH) in Western Port

1- Burns & Smith (1977) Distribution of Petroleum Hydrocarbons in Westernport Bay. In: Wolfe (Ed.) Fate and Effects of Petroleum Hydrocarbons in Marine Organisms and Ecosystems. 2 – Rees et al (1998) Toxicants in Western Port sediments. MAFRI, Report to EPA Victoria.

No substantial increase over time

1 2

Pesticide residues in Western Port

No pesticide residues detected in sediments in the bay Moderate concentrations of pesticides in estuaries and freshwaters

Pesticide residues: mode of action

Pesticide modes of action

Substantial concentrations of herbicides and fungicides Low concentrations of insecticides – primarily residues of organochlorines

Tributyltin in Western Port

Substantially lower concentrations than 1988 and 1997 Two concentrations still above ISQG low Hastings Warneet Concentrations in sediments near heavy boating areas

Sources of toxicants

Discussion of findings

Primary sources of heavy metals in marine environments1:

• urban run-off (stormwater and base flows)
• industrial effluents
• Historical activities (mining, landfill, development)
• atmospheric deposition (including dust)
• agricultural activity
• groundwater

Heavy Metals entering waterways

1 - Haynes and Johnson (2000) Marine Pollution Bulletin, 41, 267-278

Soil types across greater Melbourne and soil sampling sites ()1

1 - Pettigrove & Hoffmann (2003) Australasian Journal of Ecotoxicology, 9, 119-128

Mornington Peninsula Cainozoic sands had naturally high levels of arsenic

Organic toxicants entering waterways

Pathways that organic toxicants (TPHs, pesticides) can enter waterways:

• Surface run-off,
• Groundwater,
• Spray-drift,
• Soil erosion,
• Leaching from boat hulls,
• Atmospheric deposition,
• Spills.

Exposure pathways for organic toxicants1

1 – Keough & Bathgate (2011) Threats and exposure pathways. In: Understanding the Western Port environment: A summary of current knowledge and priorities for future research. Melbourne Water.

Organic toxicants entering waterways

Pesticides often used in intensive agriculture. Loosely bound soils and higher run-off rates

Estimating ecological threats from toxicants

No guidelines for many new and emerging pesticides

• Insecticides (pyrethroids, carbamates)
• Herbicides
• Fungicides

Need for ecotoxicology experiments

Why Manage Toxicants?

Potential decline in freshwater, estuarine and marine ecosystems

• Herbicides: impacts on marine plants1 and algae2
• Metals: impacts on marine flora3 and fauna4
• Organotins: imposex in shellfish5
• Petroleum Hydrocarbons: stress in biota6,7

1 – Haynes et al (2000) Marine Pollution Bulletin, 41, 288 - 293 2 – Jansen & Altenburger Estuarine, Coastal and Shelf Science 62 (2005) 539–545 3 – MacInnes & Ralph (2004) Journal of Experimental Marine Biology and Ecology, 302, 63-83 4 – Simpson et al (2012) Environmental Science & Technology, 46, 9038-9046 5 – Rees et al (2001) Marine Pollution Bulletin, 42, 873-878 6 – Brils et al (2002) Environmental Toxicology and Chemistry, 21, 2242 - 2251 7 – Pettigrove & Hofman (2005) Environmental Toxicology and Chemistry, 24, 2500-2508

Priority Recommendations:

• 1. Investigation of herbicides

and fungicides in estuaries and mudflats of western port to understand risk posed to resident biota.

• 2. Conduct ecotoxicity tests

with local flora to derive concentration thresholds for herbicides

Key Recommendations

Secondary Recommendations:

• 1. Continue with the existing

sediment quality monitoring program at key estuarine sites to monitor toxicants entering the bay,

• 2. Determine if sites where

elevated concentrations of metals (arsenic, nickel and mercury), organotins and TPHs were detected are having ecological effects,

• 3. Monitor concentrations of

metals in waters from waterways entering Western Port.

Key Recommendations

Further investigations

Pesticides im pacts on m arine organism s

Cattle grazing near Cape Flinders, Mornington Peninsula

Investigate Pesticide Concentrations in Western Port

New monitoring program in Western Port Objective:

• Determine if herbicides are likely to be impacting aquatic flora in

Western Port. Aims:

• Determine spatial and temporal variability of key herbicides in

sediments and waters within Western Port.

• Conduct ecotoxicology experiments to determine if key flora species

are likely to be impacted by herbicides

Investigate Herbicide Toxicity

Field – Monitoring

• Collect water and sediments samples over 2013 – 2014
• Baseflow and Stormwater events
• Determine concentrations and risk to marine flora and fauna
• Seagrasses, Grey Mangrove, Green algae, Flagellate

Lab - Ecotoxicity experiments

• Conduct experiments using marine plants and algae
• Seagrasses, Zostera capricorni, Z. nigricaulis
• Grey Mangrove, Avicennia marina
• Micro-algae (Isochrysis galbana, and Chaetoceros mulleri)

Investigate Herbicide Toxicity Mangrove ecotoxicity experiments

• Pilot study already underway (Grey Mangrove, Avicennia marina)
• Determine effects from exposure to 3 main herbicides found in

Western Port

Acknowledgements

Daniel MacMahon, Kath Hassell, Allyson O’Brien, Katy Jeppe (CAPIM) Gavin Rose, Pei Zhang (DPI) Rhys Coleman, Trish Grant, Sophie Bourgues (Melbourne Water)