General

Aquatic ecosystems are of critical ecological, economic and social importance. Their health is essential for the maintenance of water quality, aquatic and terrestrial biodiversity, aquaculture and fishing industries. The National Land and Water Resources Audit assessed overall riverine ecosystem health based on macro-invertebrate data, catchment and riverine habitat condition, hydrological disturbance and water quality. They found that NSW has the poorest aquatic biota condition of any Australian state or territory – the environmental condition of 97% of the assessed river length in NSW had been modified in various ways, including catchment disturbance from land use changes and clearing (90%), elevated levels of nutrients (especially phosphorous) and suspended solids (97%), altered hydrological regimes (87%) and modified aquatic habitat (70%). Intensity of land use appears to be the main determinant of condition – rivers in highly urbanised catchments and areas where cropping is the main land use show the most signs of ecosystem stress. Many estuarine and coastal systems are also in poor condition due to the adverse impacts of coastal development, sewage and stormwater pollution, disturbance of acid sulphate soils, reduction in floodplain and wetland areas, and extraction of sand and gravel. Despite many recent efforts to reduce the impacts of different land uses by addressing sewage and stormwater, improving management of river flow and extraction, implementing water-sharing plans, developing fish habitat plans, and establishing protected areas, amongst other actions, degradation and loss of ecosystems continues across NSW.

Key Issues

Water quality issues for aquatic ecosystem health include: salinity levels (which affects composition and species abundance and distribution); nutrients (encouraging excessive growth of algae and algal blooms that may be toxic); turbidity/suspended sediments (reduces light available for plant growth, can smother in-stream habitats, and damage fish gills and respiratory structures of other species); and the presence of pesticides, other chemicals and heavy metals in the water column or in fine sediments (with potential to accumulate within tissues and have long-term toxic effects), and acidity (run-off from acid sulphate soils kill fish and crustaceans, cause fish red-spot disease, damage or cause death of oysters and interact with sediments to release heavy metals). Other major issues involve flow regimes (impacts of high volumes of stormwater and high rates of flow; and constant flows from sewage discharges) and their variability, changes to natural tidal movements and barriers to fish movement for breeding purposes, and cold water pollution (cold waters reduce ecosystem productivity, eliminate temperature-sensitive biota and decrease survival of eggs, larvae of fish and aquatic insects).

Protocols

For methods for the analysis of water pollutants consult the EPA (1998) reference: Approved methods for the sampling and analysis of water pollutants in New South Wales. The methods are based on the American Public Health Association, USEPA standard methods and the Standards Association of Australia.

Core protocols are those for the following indicators:

Algal blooms
Aquatic ecosystem health
Diatom monitoring
Macroinvertebrate monitoring
Physical and Chemical

Supplementary protocols / information relates to:

Acid sulphate soils
Algal species density and diversity
Amphibian monitoring
Bacteria monitoring
Benthic infauna
Bioaccumulation
Chlorophyll a
Constructed wetland monitoring
Desktop monitoring using satellite data
Ecotoxicology
Endocrine disruptors
Environmental flows
Fish kills
Fish monitoring for water quality
Gross pollutant trap monitoring
Groundwater
Industrial areas
Intertidal monitoring
Landfill
Load monitoring
Mangroves
Metals in sediments
Metals in water
Oil and other spills
On-site sewage monitoring
Pesticides and herbicides
Primary Productivity
Profiling
Real time Chlorophyll monitoring
Riparian vegetation monitoring
Salinity
Saltmarsh
Seawalls
Seagrass
Streamwatch
Urban stormwater

Contacts - Core Agencies and Organisations

The main organisations with formal responsibilities include the following:

• NSW Fisheries are responsible under the Fisheries Management Act 1994 and Fisheries Management Amendment Act 1997 for the management of natural fisheries resources, conservation of fish habitats, aquatic reserves and intertidal protected areas, protection of estuarine and marine vegetation (mangroves, seagrasses, etc.) and aquaculture. They undertake environmental assessments of fisheries, review developments and works proposals that may impact on aquatic habitats and ensure habitat protection requirements are incorporated in other natural resource management planning processes (water management, land use, estuary and floodplain management planning). Together with the EPA (DEC) investigate fish kills.
• Department of Infrastructure, Planning and Natural Resources (DIPNR) manages water extraction licences from surface and groundwater, manages weirs, regulates riverbank and estuarine foreshore works through the Rivers and Foreshores Improvement Act 1948, assesses river health and investigates environmental flows and monitors water quality at key sites.

Other organisations involved

• Councils are responsible for planning and control of development within their local government areas under the EP&A Act 1979
• National Parks arm of the Department of Environment and Conservation is responsible for waters within national parks and nature reserves.
• Sydney Water Corporation, Hunter Water Corporation and Sydney Catchment Authority (SCA) are all involved in monitoring water quality for aquatic ecosystem health; the SCA also regulates flow discharges from dams within its jurisdiction.

Case Studies

Hornsby Shire Council

Moreton Bay Waterways and Catchment Partnership (South East Queensland)