Southeast Australian Shelf large marine ecosystem

Published: March 30, 2008, 8:39 pm

Source: NOAA

Topics:

Fisheries (main) Marine Ecology (main) Oceans and seas (main) Geography (main)

Introduction

Location of the Southeast Australian Shelf Large Marine Ecosystem. (Source: NOAA)

The Southeast Australia Large Marine Ecosystem (LME) extends from Cape Howe, at the southern end of the state of New South Wales, to the estuary of the Murray-Darling river system in the State of South Australia. It borders the Southern Ocean and the western boundary currents flowing into the West Wind Drift, which circulates around the continent of Antarctica. It contains the island of Tasmania and the Bass Strait, which separates the island from the Victoria State mainland in the Tasmanian Sea. The LME has a diversity of habitats such as seagrass beds, mud flats, intertidal and sub-tidal rocky reefs, mangrove kelp forests and pelagic systems. The Murray-Darling river system has a large catchment area, and it transports nutrients and sediments from the land into the coastal waters. The climate is temperate.

Productivity

The Southeast Australian Shelf LME is considered a Class I, highly productive (>300 grams of carbon per square meter per year) ecosystem based on SeaWiFS global primary productivity estimates. It is a temperate marine environment inhabited by communities rich in species. Many species are endemic to Australia. Investigations in Bass Strait and the south-eastern slope have revealed soft-bottom benthic communities more diverse than anywhere else in the world. Near the island of Tasmania, seasonal storm (Tropical weather and hurricanes) events accelerate the mixing of nutrients onto the shelf. Runoff from the Murray-Darling river system is a regional contributor to shelf nutrient processes and fluxes. For a general understanding of oceanographic processes affecting the nutrient dynamics and productivity of Australian marine ecosystems, see the State of the Environment Report. For more information on productivity, nutrient dynamics and land-sea interactions, see Furnas.

Fish and Fisheries

Some of the species harvested are scallops (in the Bass Strait), the rock lobster (Tasmania), and abalone (Tasmania and Victoria). Victoria has a small but valuable eel fishery with an annual catch of about 300 tons of eel meat. Most of the catch is exported to Europe and to Asia. Eel nets are set in swamps, lakes and coastal streams. Over the years, substantial changes have been made to the configuration of these nets to reduce any adverse impact on wildlife and non-targeted fish species. Until recently, fisheries resources were usually managed in separate fishery units. Under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act), the Commonwealth Government has a framework that helps it to respond effectively to current and emerging environmental problems, and to ensure that any harvesting of marine species is managed for ecological sustainability. For detailed fish catch statistics for this LME, see data collected by the University of British Columbia Fisheries Center. The FAO provides information on the characteristics of Australia’s fishing industry.

Pollution and Ecosystem Health

One major problem in this LME is the introduction of exotic marine organisms to the coast from the hulls of ships or as a consequence of ships discharging ballast water. These introduced marine species threaten native marine flora and fauna and local marine diversity as well as human uses of marine resources such as fishing and aquaculture. Introduced species for this LME include the North Pacific sea star (Asterias amurensis) and the Japanese kelp. The North Pacific seastar is native to northern China, Korea, Russia and Japan. It was first found in Tasmania in 1986, but was misidentified as a native species until 1992. The sea star has since spread to Victoria. At this stage its distribution in Australia appears to be limited to these two states. However, suitable conditions exist for its survival and reproduction in the West-Central Australia LME (LME #44). The sea star is a voracious predator of shellfish. This poses a serious threat to mariculture and wild shellfish fisheries. While significant research is being undertaken on the potential impacts the sea star may have in Australia, there is still not enough data available to indicate conclusively that it is having an impact on Australian fisheries. Japanese Kelp has appeared in near-shore habitats along the East Coast of Tasmania. It is spreading at a fast rate and has the potential to invade the entire southern coastline. For more information on coastal and marine pollution issues in this LME, see Environment Australia's reports on marine disturbance, other pollution reports, and the State of the Environment Report.

Socioeconomics

Thousands are involved in the fisheries, aquaculture and processing sectors of the economy. The Food and Agriculture Organization (FAO) provides information on the characteristics and socioeconomic benefits of Australia’s fishing industry. There is salmon aquaculture in Tasmania. The LME contains a number of cities and ports, including Melbourne. Industry, shipping and tourism are major economic activities. There is offshore oil and gas off the Victoria coast. Marine and coastal-based tourism is important in this LME both in terms of domestic and international tourism. The state of Victoria has a spectacular coastline, with sandy beaches and internationally known sites (Twelve Apostles, Great Ocean Road). Its marine waters contain important representations of species endemic to the Southern Ocean. A significant proportion of the Australian population is involved in recreational fishing, diving, snorkeling, and boating. Tourists from overseas prize the natural and unspoiled marine environment. There are, however, social, cultural, economic and environmental impacts caused by tourism. Tourism may affect the lifestyle of residents in ways they perceive as intrusive. Negative social impacts may include real or perceived increases in crowding, prices, or crime, as well as increase conflict between commercial, recreational and indigenous interests.

Governance

The Southeast Australia LME lies off the coast of 4 states: New South Wales, Victoria, Tasmania and South Australia. The main governance issues of this LME pertain to fisheries management and to the establishment of marine reserves. Australian fisheries resources are managed under both Commonwealth and State/Territory legislation. The demarcation of jurisdiction and responsibilities among these various governments has been agreed to under the Offshore Constitutional Settlement (OCS). Under OCS, the states and territories have jurisdiction over localized, inshore fisheries. The Commonwealth has jurisdiction over offshore fisheries or fisheries extending to waters adjacent to more than one state or territory. Each government has separate fisheries legislation and differing objectives. Transboundary fisheries and foreign fisheries are managed by the Commonwealth fishery agencies. An important goal is to ensure that the exploitation of fisheries resources is conducted in a manner consistent with the principles of [[ecological]ly] sustainable development. This includes the need to assess the impact of fishing activities on non-target species and the long-term sustainability of the marine environment. For more information on the governance of Australia’s fisheries, see the FAO (Food and Agriculture Organization (FAO)) website. National Resources and Environment is responsible for overseeing the management of the resources of Victoria's coastal public land and marine waters for their environmental, conservation and recreational value. Ninety six per cent of the coast is public land and state marine waters extend to 5.5 kilometers (km) offshore. The marine tourism industry has produced a code of conduct that covers issues such as anchoring, removal of rubbish, fish feeding and preservation of world heritage values. Australia declared a 200 nautical-mile Exclusive Economic Zone in 1978. Australia is party to the following international agreements: Antarctic-Environmental Protocol, Antarctic Treaty, Biodiversity, Climate Change, Endangered Species, Environmental Modification, Hazardous Wastes, Law of the Sea, Marine Dumping, Marine Life Conservation, Nuclear Test Ban, Ozone Layer Protection, Ship Pollution, Tropical Timber 83, Wetlands, and Whaling.

References

Articles and LME Volumes Morgan, J., 1989. Large Marine Ecosystems in the Pacific Ocean. In: Biomass Yields and Geography of Large Marine Ecosystems, K. Sherman and L.M. Alexander, eds. AAAS Selected Symposium, 377-394. ISBN: 0813378443 (Southeast Australian Shelf large marine ecosystem) .

Other References

• Edwards, RJ, and WJ Emery, 1982. Australasian Southern Ocean frontal structure during summer 1976-77. Aust J Mar Freshwat Res 1982;33:3-22.
• Emery, WJ, 1977.Antarctic Polar frontal zone from Australia to Drake Passage. J Phys Oceanogr 7:811-822.
• Furnas, Miles J., Land-sea interactions and oceanographic processes affecting the nutrient dynamics and productivity of Australian marine ecosystem.
• Pogonoski, J.J., D.A.Pollard and J.R.Paxton, 2002. Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Environment Australia.
• State of the Environment Report.

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Citation

(2008). Southeast Australian Shelf large marine ecosystem. Retrieved from http://editors.eol.org/eoearth/wiki/Southeast_Australian_Shelf_large_marine_ecosystem