Rapid population growth and expanding development impacts estuarine ecosystems. Urban and industrial development, tourism, and other uses have caused significant degradation of the coastal zone of New South Wales.
Threats from development
Over-harvesting of fish by commercial and recreational fishers and inappropriate aquaculture practices such as trawling, reduce fish stocks, limit fish reproduction and threaten estuarine food webs.
Acid sulfate soils
Acid sulfate soils are natural sediments that contain iron sulfides. They are common along the NSW coast. When disturbed or exposed to air these soils can release harmful acid, damaging waterways, built structures as well as harming animals and plants.
Tourist facilities, infrastructure and accommodation are usually located as close to coastal attractions as possible. These developments and related activities can cause loss of habitats, declines in fisheries, increased litter and reduce water quality.
Sewage and stormwater runoff are major sources of nutrients associated with urban areas. Untreated sewage can enter waterways through network overflow points, illegal connections to the stormwater network and leaking septic systems. This can effect the safety of swimming at impacted areas.
Scientists in DPE, in collaboration with the University of Technology Sydney and Central Coast Council, have developed indicators that track the source of sewage impacts on waterways at Terrigal Beach.
Draining of coastal wetlands
Significant losses of saltmarshes and mangroves have occurred near urban areas through drainage and reclamation. Perhaps more significant is the loss of coastal wetlands as a result of agricultural drainage works on coastal floodplains.
These losses affect fish and birds that use these habitats. Drainage may lead to issues associated with acid sulfate soils.