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Theme 1: Water & Catchments
Topic: Coast and Marine Issues
Different marine and coastal ecosystems
Marine ecosystems are a part of the largest aquatic system on the planet, covering more than 70% of the Earth's surface. There are many different marine and coastal ecosystems, including oceans, lagoons, beaches and dunes, reefs, mangroves, tidal wetlands, seagrass beds, estuaries and swamps. Coastal and estuarine habitats are closely linked with upstream catchments and the associated land uses, all of which have an effect on the condition of these habitats.
Why are coastal ecosystems important?
Coastal ecosystems provide many different goods and services and are important for storing nutrients, filtering pollutants from inland freshwater systems and for protecting shorelines from erosion and storms.
What are the threats to our coasts and marine areas?
The main threats to coastal and marine ecosystems are population growth, pollution, over harvesting and climate change. Pollution is the most serious problem facing our oceams. The vast majority of marine pollution is caused by land based activities; soil erosion, fertiliser use, intensive animal production and sewage and stormwater run-off. Other urban industrial discharges including detergents, rubbish (especially plastics), oils, greases, and insecticides are pollutants that affect our coastal and marine environments. The impact of over-fishing in the oceans is another serious concern, as many of the world's fisheries are already over-exploited.
South Australia's coasts and marine environments
South Australia has 4,250 kilometres of coastline, ranging from cliffs, rocky shores and sandy beaches in the south east and west coast to mud flats, seagrass, samphire and mangrove habitats in the upper St Vincent and Spencer Gulf regions. Our marine environment is an extremely valuable resource. Coastal and marine waters support large commercial and recreational fisheries, as well as aquaculture worth approximately $500 million a year to the State's economy. South Australia's marine and estuarine waters are amongst the most biologically diverse in the world.
In South Australia, some of the major threats to our coast and marine areas are:
- Loss of seagrasses and mangroves along the Adelaide coastline
- Increased development
- Pollutant loads from wastewater and stormwater
What are estuaries and why are they important?
Estuaries and the land surrounding them are places where water from the land meets and mixes with the open sea. The warm, generally shallow waters of estuaries receive nutrients from the land and sea, making them very productive.
Estuaries are 'the nurseries of the sea' because they contain large amounts of food and shelter for fish and other animals. In South Australia, several crustacean and fish species like Yellow-eye Mullet, Black Bream and Blue Swimmer Crabs spend their early life stages in these protected nutrient-rich habitats, before moving offshore into deeper water or upstream into rivers. Migratory birds, such as the snipes and the Red-necked Stint, also visit estuarine mud and sand-flats to rest and feed throughout their international journeys.
Estuaries are also used for a number of human activities and they are often cultural centres - the focal point for trade, tourism and recreation. Estuaries are generally found at the end of rivers and may be large systems, like the Murray Mouth and Coorong or small like Breakneck River estuary on Kangaroo Island. Tidal waters enter estuaries from the ocean, while river or groundwater flows from the land.
Coastal and marine facts
Did you know - Australia has 783 major estuaries.
Did you know - The total length of the world's coastlines is about 504,000 km, enough to circle the Equator 12 times. 362,000,000 km or 71% of the surface of the globe is water. Oceans influence all life on earth, and about 80% of all life is found in the oceans.
Did you know - Australia's ocean territory is the world's third largest, spanning three oceans and covering around 12 million square kilometres. More than 80% of Australians live within 100 kilometres of the coast.
Did you know - The marine and estuarine waters of South Australia support more than 6,000 invetebrates, 1,200 algae types, 350 fish species, 16 breeding seabird species, 33 mammal species and 12 seagrass species. Eight species of seals and sea lions are found in our waters, including the rare Australian Sea-lion and the New Zealand Fur-seal, both of which breed here. 95% of the seagrasses, 75% of red algae and 85% of fish species are found nowhere else in the world. Over 85% of the marine plants and animals in Southern Australian waters are found nowhere else on earth.
Enquiry Learning
- What are the different coastal and marine ecosystems?
- How are these environments connected to the rest of the catchment environment?
- Why are estuaries unique and important?
- What important ecosystem services, such as nurseries for native biodiversity, do these environments provide?
Internet Resources
Type Description Resources Covering the Topic Easy
- Coast and Marine Education Framework
- Comprehensive collection of teacher resources and activities linked to SACSA curriculum.
Department of Environment and Heritage
www.deh.sa.gov.au/coasts/
cmeducation.html
- Marine biodiversity.
- Interesting facts and information.
Oceans Alive
www.abc.net.au/oceans/alive.htm
- Water backgrounder.
- Marine waters, intertidal zones, continental shelf, seamounts, and other habitats.
NSW EPA
www.epa.nsw.gov.au/soe/
soe2000/bw/bw_1.htm#bw_1_h010
- Catchments to Coast.
- Information, activities, links and teacher resource pack.
KESAB Patawalonga and Torrens Waterwatch
www.cwmb.sa.gov.au/kwc/
programs/catchment_to_coast/
index.htmMore Comprehensive
- Summaries of Australian habitats and species in coasts and oceans.
- Thorough and important.
Environment Australia – State of the Environment Report 2001
www.ea.gov.au/soe/2001/coasts/
coasts01-1.html
- Coast and Marine Education Framework
- Comprehensive collection of teacher resources and activities linked to SACSA curriculum.
Department of Environment and Heritage
www.deh.sa.gov.au/coasts/
cmeducation.html
- 50 ways to care for the Coast.
Victorian Dept of Sustainability and Environment
www.dse.vic.gov.au/dse/nrencm.nsf/
FID/-93F1AEF92BEBDEDE4A2568310
0206630?OpenDocumentFact Sheets:
- Where's the beach?
- Protecting South Australia'’s beaches.
- Seagrasses of South Australia.
Department of Environment and Heritage-SA
www.environment.sa.gov.au/coasts/
pub.html#educational
- Biodiversity in the sea.
- Information for teachers.
MESA
www.mesa.edu.au/seaweek99/
tr_05.htm
- Ecosystem biodiversity in Australia.
MESA
www.mesa.edu.au/seaweek99/
tr_04.htm
- South Australia's marine biodiversity.
SA Department of Environment and Heritage
www.deh.sa.gov.au/coasts/
marine_biodiversity.html
- Marine ecosystems of the world.
MBGNET
mbgnet.mobot.org/
- Explains the importance of mangroves, how they function and how they are managed.
NSW Fisheries
mbgnet.mobot.org/salt/sandy/
indexfr.htm
- What is an estuary, why are they important, and why should they be protected?
EPA USA
www.epa.gov/owow/estuaries/
about1.htm
- Coastal and wetland forest.
- Fact sheet.
Qld Government
http://www.nrm.qld.gov.au/
factsheets/pdf/forest/F08.pdfWho Can Help?
Organisation Who Can Help? Coastcare Coastcare Marine Education Society of Australia (MESA) Marine Education Society of Australia (MESA) Port River Marine Watch Waterwatch: KESAB Patawalonga & Torrens Star of the Sea School Marine Discovery Centre Marine Discovery Centre Waterwatch SA Waterwatch: Broughton Wakefield
Waterwatch: KESAB Patawalonga & Torrens
Waterwatch: North Adelaide & Barossa
Waterwatch: River Murray (Upper)
