Artificial reefs

Artificial reefs ...

As the name implies, these reefs are man made and are primarily designed to provide a suitable shelter or preconditions for a habitat to promote marine life.

They're mostly an underwater structure, built for the purpose of promoting marine life where the featureless bottom.

These 'fake reefs' sometimes perform a dual function to improve wave action for surfing and/or to control beach and sand erosion.

Artificial reefs can take a number of forms using existing materials in order to create a fish habitat. This can be done by sinking oil rigs, scuttling ships, or by deploying rubble, tires, or construction debris.

Or, they can be specially designed (e.g. the reef balls) and made with concrete, PVC or other materials which will last under the saltwater conditions. concrete. Shipwrecks, usually become reefs when preserved on the sea floor.

The 'man made' reefs are generally designed to provide suitable surfaces for algae, barnacles, corals, and oysters to attach themselves.

This accumulation of marine life in turn provides intricate structure and food for a variety of fish.

As mentioned above, fake reefs have also been created for improving surfing breaks, coastal protection, habitat enhancement and coastal research.

Location maps and coordinates

* Lake Conjola The reef is constructed of 400 "Reef Balls" and covers an area of approximately 1600m2. Refer Map co-ordinate,150.472148&spn=0.006159,0.009656&z=17
* Merimbula Lake NSW DPI's fifth artificial reef. consists of 400 specially designed Reef Balls and occupies an area of approximately 1600 m2.
* St Georges Basin Check the video foottage

NSW Recreational fishers 4th reef, being installed in Lake Conjola, three hours from Sydney on the NSW south coast.

Man made reefs had previously been installed in St Georges Basin, Botany Bay and Lake Macquarie, with other potential locations currently under investigation, including Merimbula Lake.

The reef has created valuable habitat for a variety of fish species in this popular recreational fishing spot.

NSW DPI deploys these man-made reefs in areas that are lacking in reef habitat. The reefs provide a place for fish to live and shelter, and potentially redirect fishing effort from more traditional fishing areas.
Previous installations have proved that fake reefs attract a large variety of popular recreational fish species such as flathead, bream, tarwhine, snapper, leatherjacket and whiting.

The Lake Conjola reef is made up of 400 concrete modules known as ‘Reef Balls’, which can be moved, or removed, if necessary.
This was the first NSW DPI artificial reef that was built with three different sized Reef Balls to create a reef of increased complexity.

Reef Balls are made using a special mix of concrete that allows algae to grow quickly, creating ideal marine habitat for fish and invertebrates.

The Lake Conjola project received strong support from Shoalhaven City Council. DPI also worked closely with community groups, researchers, fishing clubs and other regulatory bodies to ensure the reef was placed in the ideal location to maximise its effectiveness.

Regular monitoring assesses the effectiveness of the reefs. The project also helps to provide a growing body of information about the benefits of man-made reefs as a fisheries enhancement tool.

Merimbula Lake

The waters of Merimbula Lake are also benefitting from installation of the State’s fifth and largest artificial reef, with a total area of approximately 1600 sq metres.

The Merimbula Lake artificial reef is the largest they are likely to construct in NSW as they are happy with the effectiveness of this size structure after building other smaller reefs.

Marcus Gregson said his next project is to expand an earlier trial reef in Lake Macquarie north of Sydney which started in 2005 and has informed the development of the more recent reef installations.

The Merimbula reef was made possible by $160,000 raised from the Recreational Fishing Trust project, funds collected from NSW recreational fishing licenses.

The Merimbula reef also consists of 400 reef balls, constructed of concrete mix, modified to encourage the growth of marine plants and animals.

Many species including bream, tarwhine, flathead and leatherjacket and tailor may also be found on the reefs from time to time.

Three size combinations of reef balls were used to create a complex habitat for fish, algae and invertebrates. The largest Reef Balls installed are around 1.2 m wide, 0.9 m high and weigh up to 1,000 kgs each.

The NSW DPI conducts a quarterly monitoring program of the Merimbula Lake artificial reef in August, using baited underwater video, photographic surveys and diver census

Photographs of the sea bed and the Reef Balls are also taken regularly, to record the succession of algae on the reefs and the presence of encrusting invertebrates.

The other fake reefs in Lake Conjola, Lake Macquarie, Botany Bay and St Georges Basin have already proven to offer habitat for a high diversity and abundance of recreationally important species.

The NSW DPI has worked closely with researchers, fishers, community groups and other regulatory bodies to ensure the reefs are placed in the best location to maximise effectiveness.

Artificial reefs are funded by recreational fishing license fees being put 'back into the water', to improve recreational fishing in NSW for all keen anglers.

St Georges Basin Check Video

Click here for official DPI page on St Georges Basin reef

180 reef balls (6 individual reefs) were originally placed on the basically featureless floor St Georges Basin, in February 2007.

The reef balls are constructed of hollow cement balls, with holes all the way through for fish access. The Ph of the concrete is matched to the marine environment. Apparently, artificial reefs are'nt constructed with used tyres any more and deliberately-sunken ships are also now not favored.

The reefs in the Basin are monitored by a camera lowered with bait attached, for periods of half an hour at a time, to record species & numbers. When possible, diver surveys are also used.

Levels of algae & encrusting invertebrates are also measured on an ongoing basis by the NSW DPI.

Marcus Gregson of the DPI says "St Georges Basin has very limited visibility, which is reduced even further after rainfall events.

There are 2 types of fish which Marcus describes as ‘gregarious’ & other – fish that only ever live inside the balls. 13 species have been noted. Of 6 sample species, 5 of them preferred artificial reefs. The reason for this preference for artificial reef over natural, is yet to be ascertained. Mudcrabs like to live inside the balls and sharks do NOT live in the Basin.

Photographic surveys have revealed the presence of a large number of key species in St Georges Basin, which are targetted by recreation fishers.

The St Georges Basin project has been working well since 2007. The next plan is to expand the project - larger reefs, and build up more species of larger fish.
There will be an additional 420 extra reef balls placed, resulting in a total of 600.
The additional 420 reef balls will be the next two sizes larger than first sizes.
Reef of 15m x 30m
Covering an area 3,000m2
The deployment schedule is early 2010.

Stereo video monitoring is another method to be used. This method assists in measuring the sizes of the individual fish.

This project is being funded from recreation fishing trust, primarily to increase the ‘fishing experience’ of recreational fishers. The reefs also provide habitat for juvenile & bait fish.

These reefs are only created in places where professional fishers are banned.

According to the NSW DPI, the following Recreational Fishing Havens on the South Coast are for recreational fishing only [i.e. commercial fishing is largely excluded]:

  • St Georges Basin
  • Lake Conjola
  • Narrawallee Inlet
  • Burrill Lake
  • Lake Tabourie
  • Meroo Lake
  • Tomaga River
  • Tuross Lake (including Tuross River and Borang Lake)
  • Lake Brunderee

These havens were created to improve the fish stocks and enable a better catch for the non-commercial fisherman. The Recreational Fishing Fee levied in NSW raised about $20 million to fund a buy-out of commercial operators in these areas. It seems that this strategy has worked, as we're seeing more fish for the occasional fishers in many of these fishing spots.

This has had a positive effect on tourism, generating employment and in at least one case we know about near Bermagui, the fishing charter operator re-invested the proceeds he received from the buyout, in a quality land based tourism development which provides employment and a superior wining and dining experience for the residents and visitors to the South Coast.

Please Note: The areas established for recreational fishing only include all bays, tributaries, creeks, canals and artificial lakes within that area.

Glossary of Terms:

artificial coral reef, artificial marine reefs, artificial reef locations, artificial reef sites, artificial reef society, fishing artificial reefs, how to build artificial reef

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