The Adelaide Coastal Waters Study (ACWS) has been completed and
the Final Report Vol. 1 Summary
of Study Findings (2.3MB PDF) was released by Minister Gail
Gago. For an outline of the study, outcomes and recommendations
refer to the Adelaide Coastal
Waters Study Overview (963KB PDF).
The study has been concerned with understanding the coastal ecosystem
of the Adelaide near-shore coastal environment in order to better
manage this area. The focus was on seagrass,
seafloor changes and water quality.
The ACWS was initiated by the EPA in 2001, in response to concerns
about the decline in coastal water quality, as well as the loss
of more than 5000 hectares of seagrass along the metropolitan
coastline.
The study has focused on the area of Gulf St Vincent from Port
Gawler in the north to Sellicks Beach in the south and extended
approximately 20km offshore. Although important, the Port
River and associated estuary and wetlands were not a primary
focus for the ACWS. However, the input of nutrients and other
contaminants from these sources to the coastal strip have been
investigated. The Port Waterways Water Quality Improvement Plan
has developed nutrient reduction targets for discharges to the
Port River and Barker Inlet.
Implementation of some recommendations from the ACWS will come
under the Adelaide Coastal Water Quality Improvement Plan (ACWQIP)
- an initiative of the Australian Government Coastal Catchment
Initiative being developed in 2008.
The ACWS has involved the development of a model to determine
how different components of water quality may be impacting on
the health of the marine environment and seagrasses in particular.
The findings from the ACWS indicate that nutrient-rich inputs
to Adelaide's coastal waters are the main cause for loss of seagrasses
along the Adelaide coastline. High levels of suspended solids
in the near-shore waters mainly due to stormwater flows are also
a major cause of Adelaide's poor recreational water quality.
For further information on the study findings refer to the Adelaide
Coastal Waters Study Overview (963KB PDF),
Adelaide Coastal Waters Study,
Final Report Volume 1 (2.3MB PDF) and
the 20 technical reports
on the findings of the research.
The ACWS has identified management actions to reduce inputs of
nutrients, turbidity and colour in stormwater and wastewater to
metropolitan coastal waters. The study found that present nutrient
enrichment levels are sufficient to cause seagrass loss. This
is compounded by increased inflows of turbid and coloured stormwater
and catchment runoff. The ACWS Final report identifies that management
actions need to work towards improved environmental outcomes by
reducing inputs to Adelaide's coastal waters.
