Australia Marine Conservation Society - KI Branch

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Reefs

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MARINE >> A temperate paradise, the reefs that have been forgotten



Reefs All Round!

Cool and rocky : warm and limey,

Australia has "Reefs All Round."

Reefs are some of the world's most diverse ecosystems. They are geological features that support a diversity of marine life. In the past, much attention has been paid to our tropical coral reefs. However there is a wealth of unique marine life along all our coasts.

Coral reefs are a dominant feature of Australia's warm tropical seascapes. Coral organisms produce calcium carbonates, building their own reefs. In our cooler southern waters, long sandy beaches with rocky reefs and coastal cliffs prevail. The range of organisms found on a reef is affected by water temperature, wave action, currents and rock or bottom type.

Temperate reefs are usually formed on existing rocky outcrops, but some seaweeds such as coralline algae produce encrusting calcium that helps build up reefs. Many of the rocks that form of our reefs are made from the limestone remains of ancient marine organisms and sediments.

South Australia's unique marine environment supports a rich diversity of habitats, plants and animals.
In the calm waters of our gulfs there are large seagrass, saltmarsh and mangrove areas. These are some of the largest, sheltered coastal ecosystems to be found anywhere in Australia.

One of the ways we can manage and conserve our marine environments is through the creation of marine protected areas.

South Australia was one of the first states in Australia to make laws to create marine protected areas. However since the 1970's there have been few areas set aside. In the last ten years only three reserves have been declared.

Researchers feel there is a need to have large areas managed and protected throughout all of the major types of marine regions in the state.

In planning marine protected areas for South Australia it is important to make sure that the great diversity of habitats is represented.

Some of the areas not well represented in South Australia's reserve system include cool water kelp forests, soft-bottomed areas, estuaries, beach habitats and wave-exposed cliffs.

As well as protecting habitats, there may also be a need to improve the conservation of some species such as reef fish, seadragons, seahorses and pipefish, Great White Shark and some shellfish and other invertebrates.

There is a growing public awareness of the need to ensure our marine environments are adequately protected and conserved.

Historically, the rapid development of agriculture and industries has lead to many of our unique landscapes being altered or lost. We have a great opportunity not to repeat the process in our seas.

With the rapid development of marine industries such as aquaculture, we need to ensure that our unique "seascapes" are conserved, and that developments that may impact on them are managed in an environmentally sound way .


Australia, a special place on land and sea.

We always knew our terrestrial flora and fauna were special, but our coast and oceans are proving to be even more diverse, with many of the species unique to Australia. Millions of years of isolation from other continents has resulted in Australia's plants and animals evolving in ways very different from anywhere else. Australia's 37,000 kilometres coastline and nine million square kilometres of seas supports some of the greatest number of marine species (biodiversity) in the world.

We have the largest and oldest living marine organisms in the world in the Great Barrier Reef and the stromatolites of Shark Bay, Western Australia. Australia's fish fauna is the richest in the world with over 4000 species. This is due to the range of climatic conditions, ocean currents and the presence of the world's largest coral reef, and our long south facing coastline.

The northern tropics have the largest diversity of many species, but the southern temperate area has a higher per cent of species unique to Australia (endemic). The Great Barrier Reef alone supports 400 coral species, 1500 fish, over 4000 molluscs, 23 marine mammals and 215 bird species. All of these areas are part of our outstanding natural and cultural heritage which we have a responsibility to conserve and protect.


The Unique South

Southern Australian rocky reefs and marine environments are unique because of their long period of isolation and the length of east-west coastline facing the southern oceans. The rocky reefs of Southern Australia are dominated by marine algae or seaweeds and invertebrate animals live on the rocks or attached to plants and other animals. While coral reefs tend to have a greater diversity of fish, the cooler temperate reefs have an incredible variety of marine plants and invertebrates such as sponges, sea quirts (ascidians), lace corals and sea moss (bryozoans).

The number of species that are found only along our Southern coasts (endemic to) is very high. Some 85% of fish species, 95% of molluscs and 90 % of echinoderms are restricted to these southern temperate seas. This contrasts with 13% of fish, 10% of molluscs and 13% of echinoderms which are endemic to our tropical regions. Our southern coastline also supports one of the largest numbers of marine flora, with over 1100 species of red algae alone, 25% of the world total, 75% of which are endemic.


Our Coral Coasted North


Coral reefs are actively built by plants and animals. The architects of coral reefs are tiny animals called coral polyps. Polyps build skeletons of limestone and divide to form new polyps to create coral colonies.

A coral colony is not a group of individuals living together for the common good, but rather the result of growth and division of an original founder polyp.

Coral colonies provide the framework around and within which live all sorts of reef animals, such as fish, sponges, worms, starfish and molluscs. Dead corals, bound together by their own limestone and that of the skeletons of plants known as coralline algae, make up a reef. Over thousands of year, coral growth, death and cementing build a reef many metres thick, with a veneer of living corals and a myriad of associated plants and animals.

Even in coral reefs marine plants play a key role. Most corals contain tiny algae called zooxanthellae (which means "living in animals" and "yellowish brown" algae). The coral polyps take in oxygen from the water and expel carbon dioxide, and the zooxanthellae use their green chlorophyll, sunlight and the carbon dioxide to produce food.

On all reefs, "algal turfs" form fuzzy carpets over rocks and dead coral. These provide an important food source for grazing shells, crabs and fish. However, if these grazers are removed, or if too many nutrients enter the water, these and other algae can bloom, smothering the reef.

The Great Barrier Reef, north-eastern Australia, is the largest group of coral reefs in the world stretching for over 2000 kilometres. The Ningaloo coral reefs, off north-western Australia, stretch for some 230 kilometres. Coral reefs are also found in other tropical northern waters of Australia such as in Darwin Harbour, in parts of the Gulf of Carpentaria, and around our island territories such as Cocos Keeling and Christmas Island. Where tropical and temperate waters meet along the NSW and Western Australian coasts, a mixture of reef fish and other organisms is found.


All Day Suckers or Snarers?


Many of the animals, such as sponges and seasquirts or ascidians, that make up temperate reefs are "filter feeders". They depend on the myriad of tiny plankton in the surrounding water for food, pumping water within their 'bodies' and filtering out their food. Coral polyps however use tentacles with stinging cells to capture and ensnare their planktonic prey, as well as the tiny plants or zooxanthellae living within to produce food.

Loving Our Reefs to Death?


Some Australian states have taken the initiative to protect intertidal reef areas from the impacts of bait and shellfish collecting. Recent studies on inshore reefs show that even constant walking on reefs causes impacts, reducing the types of plants and animals that occur. In coral reef areas inexperienced and clumsy divers damage reefs by bumping into corals. As sites are damaged there is pressure from operators and tourists to move to other "pristine" sites, increasing the area of disturbance. Researchers have been experimenting with ways to 'glue back' or fasten damaged coral to repair reefs. However we need to think about how to manage human activities on reefs to minimise damage and impacts.


Reef Fish Residents


Reefs provide a source of food and shelter for many fish species, while other fish visit to feed or spawn, spending their time in open waters or other habitats. Temperate rocky reefs support a variety of fish, many of which are unique or endemic to Australia. Of the 600 inshore fish species known from temperate coastal waters, 85% are found nowhere else. Typical cool water reef fish include wrasses (family Labridae), leatherjackets (family Monacanthidae) scalyfins (family Pomacentridae, genus Parma) Old Wives (family Enoplosidae), Boarfish (family Pentacerotidae) Morwongs (family Cheilodacylidae).

A larger number of fish species occur in the tropics, the Great Barrier Reef alone supports some, 1500 fish species. In the tropics different fish dominate the seascape. We still find many wrasses and some leatherjackets here. Large Coral Trout (family Serranidae), sweetlips (family Pomadasyidae), goatfish (family Mullidae) many parrotfish (family Scaridae), surgeon fish (family Acanthuridae) butterfly fishes (family Chaetodontidae) are but a few of the diverse families found on coral reefs. Many species found in our tropical waters are widespread throughout surrounding tropical seas of the Indian and West pacific oceans.


From Wrecks to Reefs

Many diving and fishing groups have sought to establish artificial reefs. Some use old car tires, others sink old ships and barges. Some researchers argue that these reefs merely act to congregate fish, making them easily caught by recreational fishermen. Others feel that they may increase local populations of some fish species by providing more habitat. Whatever the outcomes it is important to ensure we do all we can to conserve and manage our existing reefs. To avoid conflict between divers and fishers it is important that some artificial reefs that are established be managed as no-take marine reserves.

Fishing for the Future

Fishing is one of our most valuable marine industries. However there are a number of concerns relating to fisheries management that affect our reefs:

  • The increased capacity to exploit fish stocks due to increased effort, new technology and days spent at sea
  • Declines in fish stocks globally and in Australia
  • The alteration of spawning and nursery grounds through fishing practices or coastal development
  • The lack of field monitoring for some fisheries and lack of information on the status of many species fished.
  • The impacts of aquaculture on marine habitats and the exclusion of fishers and other users from areas where aquaculture is developed.
  • The death of many non-commercial species or 'by-catch' in some fishing fleets, and the impacts on threatened species such as turtles and dugongs, some sharks and sea lions
  • Spearfishing and recreational fishing can remove long lived, slow growing species such as Coral trout and Blue Groper
  • Changes in the structure of fish populations if grazing fish or predator species are changed may adversely affect marine habitats.


Coral Crunchers

Many people imagine underwater seascapes to be a silent place, but a dive on a reef can be quite a noisy experience. Many fish, shrimp and other marine life make an array of sounds, cracklings, pops and squeaks. On coral reefs the sound of parrotfish nibbling coral produces a distinct crackling sound. Many of these parrot fish species nibble on dead coral, feeding on the algal that grow on their surfaces, one species the Bumphead Parrotfish, bites off chunks of living plate coral. These fish appear to be important in keeping algal growths in check that may otherwise smother the reefs. Overfishing of these fish may lead to loss of coral reef areas.

Source: Article by David Bellwood 'Coral Reef Crunchers' in Nature Australia, Autumn 1996, Australian Museum.

Trawling is regarded as one of the most environmentally dubious fishing methods. It is estimated that 70% of the Great Barrier Reef lagoon is trawled at least once a year, impacting on the bottom living (benthic) communities. Compared to other fishing nations, Australia appears to be lagging in the development of selective fishing gear.

The impacts of recreational fishing have been largely un-monitored, but studies suggest that the recreational catch for some species is substantially greater than the commercial catch, with up to 90% of some estuarine fish and more than 50% of all fish caught in the Great Barrier Reef.

On the east and south coast of Australia, it is estimated that the recreational catch for some species is as much, or more than the commercial catch. Existing fisheries management measures for recreational fishing appear to be quite inadequate for current levels of fishing activity. Some researchers and managers feel that states should begin registering amateurs and their licence fees, like those of commercial fishers, go towards the high cost of fisheries management and research. In other words, it would be an environmental use fee.


Project Aware: Helping to Conserve Sydney's Rock Platforms


In the past forty years, the immense variety of marine species has declined alarmingly, causing great community concern. The reasons for this decline include natural and human impacts. While rock platforms are tough, withstanding the heat of the searing sun as well as the tremendous forces of wave impact, they are unable to protect themselves from human interference. One of these impacts is the collection of rock platform organisms for bait, food, curiosity, education and beach curios.

Project Aware, was a free training project set up by Pittwater Council, in New South Wales, to educate "reef carers" in the community. These reef carers can then help educate and change community attitudes and promote sensible use and conservation of local reef platforms.


You, Poo, and a Boat or Two: Threats To Reefs

Pressure on coastal areas and reefs comes mainly from rapid population growth along the coastal strip. In the past two decades, townships have sprouted in areas previously uninhabited. Between 1971 and 1991, the population of non-metropolitan coastal areas rose by 95%, from 2.1 million to 4.1 million. Counting the major coastal cities, close to nine out of ten Australians now life in the coastal zone. With these increases in population come an increase in human impacts including:

  • Coastal urban and industrial development has resulted in sewage discharges, contaminated stormwater and soil run-off and, industrial waste discharges. Nutrients can cause algal growth on corals and rocky reef organisms which smother them.
  • Tourism developments such as the construction of resorts and marinas, siting pontoons and providing transport infrastructure, as well as increased fishing and diving. The impacts of anchor damage on corals are well documented in the Whitsunday region.
  • Impacts of nutrient loading from rural activities (fertiliser use), and poor catchment management, shipping and dredging which may create sediments which smother and kill reefs.
  • Environmental impacts from shipping and port activities such as the operational and accidental discharges of oil from vessels.
  • Boat anti-fouling paints containing tri-butyltin are known to affect shellfish populations. The impacts of mooring numbers of boats with toxic anti-foulings moored near reefs is unknown.
  • Impacts of fishing. Overfishing can remove the top order predators and some important grazing fish that are essential for healthy reef systems. Some fishing practices can physically damage reefs.
  • Declining visitor experience is becoming an issue in some areas of the Great Barrier Reef Marine Park. This is not surprising considering the issues listed above.
  • There have been a number of outbreaks of predators, such as Crown of Thorn starfish which have damaged coral reefs. Whether these are prompted by changes caused by human activities and whether reefs will recover given the increased pressures from human activities is an issue of concern.
  • In the reefs of Ningaloo, an outbreak of Drupella, a small coral-eating snail damaged large areas in the 1980's. These outbreaks have been related to overfishing of predator fish species.
  • Our reefs and other marine environments may also be threatened by introduced plants and animals, from ship's ballast water and other introductions.
  • The coral killing 'black line disease', related to nutrient enrichment caused by blue-green algae has been found on the Great Barrier Reef.

The Thin Black Line: Black Band Disease


A previously unknown coral killer black band disease has decimated reefs in Central America. Microbiologically, Black Band is similar to mats formed by blue- green algae blooms in nutrient polluted streams and lakes. The symptoms of the new disease, first seen off Belize in Central America, were alarming. A thin black line moved across the surface of a living coral head. In a matter of days to weeks, it left behind only a white skeleton. The line advanced as much as two centimetres a day and could kill a century old brain or star colony in a single summer. It has now been found in most tropical seas of the world. Australian Institute of Marine Science researchers have reported it is now present on approximately 19% of reefs in the Great Barrier Reef region. Almost certainly, nutrient enrichment in the marine environment, often related to sewerage discharge, causes many of the outbreaks. Stress on coral makes them more susceptible to disease. The two factors which stress coral are nutrients and sediments

Source: Article by James Thompson, Whitsunday Reef Monitoring Project in Wildlife Australia, Spring 1996.


Anchors Away!


As more and more people visit our reefs, there is the danger that they will damage them. Boat anchors can be particularly damaging to coral reefs and sponge reefs. Marine authorities are becoming aware of the need to manage busy boating areas by installing moorings and at times limiting the number of boats that can stop in an area to minimise damage.

OUCH And Public Moorings In the Whitsunday's

As far back as the mid 1980's, divers have known that the corals of the fringing reefs of the Whitsunday Islands were suffering from anchors being dropped upon them. In 1990, Great Barrier Reef Marine Park researchers found damage in every cove they visited. Their report called for moorings immediately, yet there were still no public moorings in June 1994. However, after potential adverse media coverage, the Great Barrier Reef Marine Park Authority has allocated $100,000 for Whitsunday moorings and marker buoys.

The group has been named The Order of Underwater Coral Heroes (OUCH). OUCH volunteers go out one day each month to survey the edges of the fringing reefs. These divers are not Greenies, per se, but rather professional dive-masters and instructors whose livelihood depends on a healthy and beautiful reef. OUCH then makes recommendations on placement of the markers and moorings. The local community has been extremely generous in their support, donating funds for fuel, and providing dive vessels. Other donations have included the use of smaller boats as dive tenders and lunches. To date, 16 moorings have been installed by QDEH at 7 sites, and marker buoys on another 7 fringing reef edges.

Contact: OUCH PO Box 706, Whitsunday, QLD. 4802.


Reef Rescue Solutions

  • Better catchment management can help reduce agricultural run-off and sediments that harm our reef environments.
  • Sensible recreational and commercial fishing practices and management can help prevent damage to reefs and also reduce the impacts removing top-order predators or certain grazing organisms can cause.
  • Marine protected areas can help our reefs and provide areas for us to appreciate the full range of marine life that live amongst our reefs. Large areas of Australia's marine environment still have only a few MPAs, and in many areas there are none at all. Others that have been designated are so small that their effectiveness is open to question.
  • Ensuring coastal developments are subject to environmental impact assessment process open to public scrutiny. Such assessments need to identify possible threats to the marine environment and possible impacts to our valuable commercial fishing industry.

Saving All The Parts


"The first rule of intelligent tinkering is to save all the parts." Aldo Leopold.

One of the best ways we can protect our reef environments and fish stocks is no-take marine reserves around our coastline. But reefs are not the only things we need to protect and manage. To ensure the sustainability of our marine environments, we need to conserve an array of the diverse marine and coastal environments around our coast.

Modern fisheries managers are starting to recognise some of the limitations of traditional fisheries science in managing marine resources. Fish stocks and species are difficult to estimate and develop models of management. Combinations of management approaches may be our best means of managing the marine environment. One of the important tools for marine conservation and fisheries management is establishing no-take marine protected areas.


Reefwatch


Conservation and dive groups in South Australia are taking the lead in highlighting the intense pressure facing our unique temperate reefs. Reefwatch is a community-based reef monitoring survey, organised by the Conservation Council SA in association with local divers and universities. The project, funded by the Environmental Protection Authority and Coastcare will produce survey kits and training programs for local dive clubs to monitor six metropolitan reefs, with the program later extending to other areas. Each dive group will undertake to "adopt a reef", carrying out monitoring and help with community awareness of our unique marine environments.

For details of these and other Coastcare & marine projects contact your regional Coastcare or MCCN coordinator.

Walk and Talk for Reef Conservation

A guided walk is one of the most effective ways of making others aware of the marine environment and reefs. A walk can be organised for most sites, the limitations are the numbers of people you can manage and what the area can handle. Animals on some rock platforms have been collected so extensively that some species are greatly diminished. We can help our local coastal environment if we keep some of the following guidelines in mind.

The Do's

Do lead by example and develop a caring, conserving attitude to our foreshores.

Do share with your friends, neighbours and children your desire to protect the animals and plants on rock platforms on our coast.

Do show people who are foraging illegally Council's or Fishery advisory signs (if available) and, in a friendly manner, remind them of the restrictions. Fisheries leaflets are available in many languages.

Do tread carefully and try not to damage any animals or plants.

Do remember to check the tides and weather conditions.

The Don'ts

Don't take any souvenirs away from the rock platform with you. Store what you've seen in your memory or camera.

Don't turn rocks over and leave in hot sunlight. Most animals or plants on the underneath surface will die if exposed to the sun. Those on top will die if buried.

Don't remove any marine creatures for bait. If you want to go fishing, bring your bait with you.

Don't leave food scraps, plastic, litter or discarded fishing line on the reef.

"Please don't eat our neighbourhood". What may be a gourmet delicacy in other countries are cherished for their untouched beauty in Australia.

Ancient Reefmakers

You don't need to be near the coast to explore a reef. Australia has a number of ancient fossil reefs formed millions of years ago and now exposed on dry land. Some of Australia's oldest reef organisms were not corals but Archaeocyathids, ancestors of sponges, that appeared over 500 million years ago during the Cambrian period.

Coral became abundant over 400 million years ago during the Ordovician Period when shallow, warm seas covered what is now north west and central Australia and Queensland.

Corals, algae 'strommatoporoids' and other organisms formed vast reefs during the Devonian Period from 408 to 360 million years ago. Remains of these Devonian coral reefs can be found at and Windjana Gorge in the Kimberley and along the Canning Basin of WA, where an ancient, broken reef stretches for over 300 kilometres.

Fossils of the world's oldest known marine creatures, jelly-fish like creatures and worms, are found in the Flinders Ranges of South Australia. These Ediacaran fossils from 630 million years ago, have given researchers an insight into our ancient seascapes before the great reef makers.


What Can I Do?


Show your concern for the marine environment by acting in a responsible way:

Cut down on the amount of plastic that you use. Reuse and recycle whatever you can.

Do not dispose of plastic or sanitary items down the toilet.

Choose "green" products and consume less. Are they really "green" though? Find out.

Buy Organic, responsible farming can save our seas. Pesticides and fertilisers used in commercial farming inevitably make their way into our oceans through rivers and streams.

Speak Your Mind, let your elected officials know how you feel about the state of our oceans. You elected them, now put them to work on behalf of our environment.

Never dispose of oil or oil based products down the drain. (Much of this oil can be recycled so find out where your nearest recycling facility is located and take it to be recycled).

Don't buy products with excess packaging that is not reusable, and let the storekeeper know why.

Contact your local port or marina and inquire whether they have adequate waste reception facilities. If they haven't, lobby your M.P. to have them installed.

Know the fish you buy. Eat 'low on the food chain'. Try to avoid eating species that are long lived and slow growing. or that may be caught or grown unsustainably.

Leave More Fish in the Sea, if you are going to fish, fish responsibly. Catch what you need and eat what you catch. Remember that many species of fish are suffering from overfishing.

Education for Everyone, learn the facts about our oceans and the dangers they face and then share them with others. Actual positive change begins with us.

Learn to snorkel or dive, so that next time you visit the coast you can see for yourself the amazing wildlife that you have been learning about. If you do not want to snorkel, why not go rock-pooling.

Talk to your Coastcare or MCCN Coordinator about reef and marine projects you and your local community can be involved in. Coastcare provides grants to a range of groups working along our coasts.


Soft Bottoms Need Help Too!

A floating soup of life, made up of microscopic plants (phytoplankton) and animals (zooplankton) is the basis of life in our oceans. Reefs are just one part of our complex marine environment that depends on plankton. We need to think and care about all marine habitats from sandy soft bottoms up to reefs. Even what appears to be barren muddy bottom can contain a surprising variety of life when we take time to explore.


References and Further Reading:

Australian Marine Conservation Society, How to save our Oceans & Coasts, 1996.

Bennet, I. & Mather, P. (eds.) A Coral Reef Handbook, Surrey Beatty & Sons, 1993.

Christianson, I.G. et al Seaweeds of Australia, , Reed Books, 1988.

Coleman, N. Various marine natural history guides and publications.

Dakin, W.J., (1987). Australian Seashores. Angus & Robertson Publishers : Sydney.

DEST 1994. Australia's Biodiversity, an overview of selected significant components. Biodiversity Series, Paper No. 2, Biodiversity Unit, Dept. of Environment, Sports and Territories, Commonwealth of Australia.

Endean, Robert, Australia's Great Barrier Reef, Uni. Qld. Press, 1982.

Gould League of Victoria, Coastal Wildlife, 1988.

Gommon, M.F., et al, Fishes of the South Coast, State Print, Adelaide, 1994.

Great Barrier Reef Marine Park Authority, various publications and information sheets.

Kailola, P. et al. (1993). Australian Fisheries Resources. Bureau of Resource Sciences, DPI, Canberra.

Underwood, A.J. & Chapman, M.G., Coastal Marine Ecology of Temperate Australia UNSW Press

Underwood, A.J. & Chapman, M.G., Seashores, A Beachcombers Guide, UNSW Press

White, M.E., The Nature of Hidden Worlds, Animals & Plants in Prehistoric Australia & NZ, Reed, 1990.

Zann, L.P. (ed.) 1994. Our Sea, Our Future. Major Findings of the State of Marine Environment Report Australia. also Technical Annexes & Summary, Ocean Rescue 2000 Program, Dept. of Environment, Sports and Territories, Commonwealth of Australia.

This information sheet was compiled by the Marine & Coastal Community Network and the Australian Marine Conservation Society to celebrate 1997, The International Year of the Reef.

 

 

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