6 Marine environment | Key findings
State of the Environment 2011 Committee. Australia state of the environment 2011.
Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities.
Canberra: DSEWPaC, 2011.
The overall condition of the Australian marine environment is good.
Compared with the marine waters of other nations, Australia's oceans are considered as being in good condition. This is a testament to the limited pressures of the past century, combined with relatively good management of high-priority and emerging issues in recent years.
Areas near the coast are suffering.
Despite the overall good condition, there is substantial degradation in the east, south-east and south-west. Ecosystems near the coast, bays and estuaries in these regions are in poor to very poor condition. Much of the impact occurred in the mid-19th and 20th centuries, and the recent impacts principally arise from unregulated human activities in river catchments, urban and coastal developments, and fishing. Aquaculture in coastal waters has resulted in major disease outbreaks that have affected the ecology of native species. Oyster reefs, which formerly occurred in many estuaries across the south-east region, were mined for lime in the 1800s and are now functionally extinct. There are also major new pressures developing for these coastal waters, including the impacts of the changing climate.
There are significant existing impacts on the oceans caused by human activities.
Fishing and offshore developments, particularly oil and gas extraction, all have local impacts on marine biodiversity. The pattern of impact is different between the north and the south, and between the east and the west—aligned with the distribution and intensity of the pressures.
An extended continental shelf has been granted.
Under the provisions of the United Nations Convention on the Law of the Sea, in 2008 Australia was granted a large (23%) increase in the seabed territory it controls. This is now 13.86 million square kilometres—the third largest national marine territory in the world's oceans.
The ocean climate is changing and we need to prepare to adapt.
Changes in the world's climate are affecting Australia's oceans. There are likely to be major impacts in the coming decades from increasing sea level, increased severity and incidence of extreme weather events, altered ocean currents and associated changes in productivity, increasing acidity of the oceans (resulting from higher carbon dioxide levels), and changing patterns of biodiversity and productivity in nearshore waters. Although there are currently only limited signs of changes in ecosystems, these will develop further and have important consequences for our coastal communities, wildlife and fishing. Planning to cope with these incremental impacts will require considerable strategic investment and leadership from governments working with communities and the private sector.
Our understanding of major aspects of our unique biodiversity is limited.
Our knowledge of seabed geology and topography, oceanographic systems and physical processes has increased, but our knowledge of biodiversity and ecological processes remains limited. Ongoing research programs in marine biodiversity and ecological function are a high priority and, because our existing knowledge base is dominated by information about fished species, it is particularly important to increase our understanding of non-exploited species and their roles in maintaining healthy and resilient ocean ecosystems.
The lack of a nationally integrated approach inhibits effective marine management.
The cumulative pressures on our marine ecosystems are rapidly growing. Impacts from climate change are beginning to escalate, population pressures and coastal development continue to grow, globalisation of marine industries continues, the risks to tropical waters from oil and gas developments are increasing—but our understanding of how ocean ecosystems operate is still very limited. In addition, present-day management systems lack integration among the various federal, state and local government systems that provide for planning, regulation and management of the marine and estuarine waters. These weaknesses significantly impede the design and delivery of efficient and effective policies and programs to maintain healthy and productive marine ecosystems and oceans. Foremost among the many issues is the lack of an integrated national system for assessment and reporting of marine condition. Without an integrated and genuinely national system of multilevel governance for conservation and management, it will be difficult to properly maintain the natural wealth of our oceans in the face of the challenges ahead.