Coast & Estuaries
Page 225
Gulf St Vincent & the Coast - Condition & Pressures
Water Quality
The EPA monitors water quality at metropolitan beaches (twice monthly in
summer and monthly in winter) providing an indication of water quality for
swimmer health and safety by measuring faecal bacteria (Enterococci) and
water clarity (turbidity). Faecal waste pollution in coastal waters comes mainly
from treated sewage discharges, boats and stormwater runoff. Poor water
clarity reduces visibility which can limit the penetration of light to the lower water
levels, resulting in reduced seagrass growth. Water clarity problems are caused
by particulate matter and sediment in stormwater runoff (soil erosion), and
industry and sewage discharges.
The EPA's Water Quality Monitoring Program also takes monthly water samples
from Semaphore and Largs Bay beaches. The samples are taken from the end
of a jetty, or where there is no jetty, from approximately 50 metres from shore,
and are used to monitor the health of the marine ecosystem.
Condition Indicator:
EPA Water Quality Monitoring Results
The EPA currently has 10 water quality monitoring sites within the Port Adelaide
River, Estuaries and Coast associated with the City of Port Adelaide Enfield.
The EPA develops coastal ecosystem condition reports similar to the aquatic
ecosystem reports, for its State of Environment reports. .
The coastal water quality site information is available on the EPA website:
oring_data
Impacts on Marine Ecologies
The Adelaide Coastal Waters Study was initially established by the EPA ( with
the CSIRO) in 2001 to address concerns about declining water quality and the
dramatic loss of around 5,000 hectares of seagrass along the metropolitan
coast since the 1940s. The research aims to quantify the input of nutrients and
other pollutants due to a variety of factors.
The Adelaide Coastal Water Study (ACWS)
Final Report Vol. 1 Summary of
Findings
was released in 2008. The ACWS involved the production of 20
technical reports that presented the research findings
of modelling exercises
that sought to determine how different components of water quality impact on
the health of the marine environment and seagrass in particular (EPA 2011).
The key findings from the ACWS indicate:
•
Nutrient-rich inputs to Adelaide's coastal waters have caused loss of
seagrass along the Adelaide coastline
•
High levels of suspended solids in the near-shore waters from stormwater
flows and beach dredging impair recreational water quality
