Introduction
The state's estuaries and coastal waters support important ecosystems,
including seagrass, macroalgal reef habitats, fish, invertebrates
and many species of marine mammals such as dolphins and seals.
These waters provide habitat, nursery and harvest areas for commercially
significant fish and crustaceans. Marine aquaculture continues
to increase around the Eyre Peninsula and in the South East of
the state. Coastal beaches provide swimming, recreational fishing
and surfing opportunities across much of the state and are very
important for tourism.
What are the problems confronting estuaries
and coastal waters?
Water quality in coastal and estuarine areas is greatly affected
by how the surrounding area is used. Major land uses in coastal
catchments that affect estuaries and coastal waters include pastoralism,
cropping, horticulture, aquaculture, forestry and urban areas.
Additionally, waste water treatment plants and sewage treatment
and effluent disposal systems discharge significant quantities
of nutrients and organic matter into estuaries and coastal waters.
Stormwater and wastewater from coastal towns have increased the
amount of nutrients, heavy metals, organic matter and microbiological
loads discharged into estuaries and coastal waters.
These pressures have significantly influenced several of the
state's estuaries and coastal waters. The breakdown of organic
matter in the Inman River Estuary
sediments and nutrient processing cause high levels of ammonia
in the estuary (over 40 mg/L), which is toxic to numerous species,
particularly fish, and can cause algal blooms. The Onkaparinga
and Cygnet Estuaries also have excessive amounts of nutrients
and organic matter.
Seagrass losses in Nepean
Bay and Boston Bay are probably
due to elevated nutrient levels. Seagrass and mangrove losses
in the Spencer Gulf coastal waters have been attributed to a combination
of nutrient enrichment, industrial pollution and climatic conditions.
It is also likely that at least some of the seagrass loss in Rivoli
Bay (in the South East) is attributable to discharges of agricultural
drainage water from Lake George.
What is being done to reduce the impacts in
estuaries and coastal waters?
Efforts to reduce the effects of land-based activities on estuarine
and coastal waters have been through management of coastal catchments
and industries. Coastal water quality management is a multi-agency
approach that involves the EPA, NRM
Boards, Primary
Industries and Resources SA, Local
Government and Department
of Water, Land and Biodiversity Conservation.
The EPA's strategies include:
- development of Codes of Practice and Guidelines linked to
the Environment Protection (Water Quality) Policy
- audits of industries including dairy and landfills
- input into changes of development policy
- licence management of licensed industries
- risk assessment of endocrine disruption chemicals
Initiatives by other government agencies including partnerships
with the EPA:
Water quality monitoring
The EPA monitors the following coastal and estuarine waters:
Reports
Ambient Water Quality of Nepean
Bay, Kangaroo Island: Report No. 1: 1999-2004 (2.8MB)
Links
Natural Resource
Management Boards
This page was last modified 18-12-2007
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