Abstract

Iron Cove, Hen and Chicken Bay, Homebush Bay, and Rozelle/Blackwattle Bay are offchannel embayments on the southern shoreline of Port Jackson. These shallow (<8 m water depth) embayments are mantled by bioturbated surficial sediments of easily resuspended oxic material (>90% mud), termed the hydrous layer. Sediment in these offchannel embayments is highly enriched in metallic and organic contaminants and each embayment is characterised by a distinct ratio of heavy-metal concentrations. Heavy-metal concentrations and total-organic and sulphur contents of sediments decrease rapidly seaward from storm water canals and other point sources. Sediment traps deployed at six locations in Iron Cove, each week for two periods of 16 and 26 weeks, provide time-integrated samples and settling rates of particulate matter from the overlying water column. Settling rates recorded during summer deployments were four times higher than during winter. Comparable heavy-metal concentrations between settling particulate matter and the ambient hydrous layer at each trap location imply that the majority of the trapped material is derived by resuspension. The relative contribution of the many processes which may resuspend surficial estuarine sediment, e.g. physical (wind-generated waves, tidal action , stormwater runoff), biogeochemical (bioturbation, flocculation and dispersion), and anthropogenic (trawling, boating, engineering construction) are discussed. The implications of these findings are that toxicants bound in sulphidic sediments are continuously remobilised into the water column. Resuspension and secondary sourcing of highly contaminated sediments probably occurs in many of the extensive shallow water environments of Port Jackson and other affected estuarine systems, thereby providing a pathway for contaminants to enter the foodchain.
Google map showing geographic bounding box with values North bound -33.76 East bound 151.33 West bound 150.99 South bound -33.94
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Product Type/Sub Type

nonGeographicDataset

Constraints

Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2000-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

81566 Product http://www.ga.gov.au/metadata-gateway/metadata/record/81566/

Keywords

GA Publication
Journal
NSW
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-33.76
East bound
151.33
West bound
150.99
South bound
-33.94

Digital Transfer Options

onLine

Distributor

Role
distributor
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

fae9173a-71fb-71e4-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
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