Artificial Reefs

The benefits of artificial reefs are recognised around the world, as positively impacting local communities and aquatic environments. An artificial reef is any man-made or altered material placed into an aquatic environment to mimic certain characteristics of a natural reef and can often shift diving and fishing pressure from other locations.
To date, artificial reefs have been deployed in over 50 different countries globally, and are used for energy production, SCUBA, surfing, eco-tourism, erosion mitigation, aquaculture and conservation, however in most cases they are used for commercial and recreational fisheries enhancement.
Artificial reefs enhance fisheries by creating additional habitat and shelter as well as food sources and a colonising surface for organisms such as algae, coral and sponges. The reefs also create different habitats by causing variations to hydrological effects such as shade, temperature, water movement and interstitial spacing (habitat between reef modules). These factors combine to create diverse marine communities and ecosystems.
“Artificial reefs provide a complex habitat for a range of different species. Once algae, corals and invertebrates make themselves at home, they produce additional biomass in the food chain, creating a food source for fish and other species”, Recfishwest Research Officer James Florisson

Artificial Reefs in Western Australia

Artificial reefs in Western Australia have been a product of community drive and passion with local fishers pushing for reef installations,  transforming areas devoid of bottom structure and habitat to underwater ‘forests’. The main source of reef funding to date has been through the Recreational Fishing Initiatives Fund (RFIF), whereby 25% of fishing licences fees are invested into projects to benefit the community’s fishing experiences.

Reefs are required to be of a certain volume in order to ensure they become habitat production devices, rather than simply drawing fish in from other areas.

Artificial reefs have also benefited the broader local community by supporting local businesses and the economy through increased fishing tourism. The artificial reefs provide not only an opportunity for ecological growth under the water, but also social and economic growth for the community.

To date four artificial reefs have been deployed in WA. In 2013 two artificial reefs were deployed off the coast of Dunsborough and Bunbury. Each of these reefs consist of thirty 10 tonne 3m3 concrete modules in six clusters of five aimed at providing habitat for target species such as Samson fish, pink snapper and silver trevally.

In April 2016 a third artificial was deployed near Mandurah. This reef was constructed out of the same modules in the same configuration as the south west reefs. Finally in late 2016/early 2017 two metal ‘fish towers’ were deployed south of Rottnest Island near Perth. Each of these modules is 4 storeys high, weighs 70 tonnes and due to their large amount of vertical habitat, provide shelter and food for a variety of different fish species. There have also been three more reefs funded to be deployed in the near future in Esperance, Exmouth and Dampier.

The local fishing community have real ownership of the development of artificial reefs as well as provide expert advice to maximise the fishing opportunities for everyone in the region.

There is no doubt that the fishing community will continue to grow a sense of stewardship for artificial reefs as we see more and more deployed throughout Western Australia.

Artificial reefs in WA complement Western Australia’s robust and adaptive fisheries management approach ensuring fish stocks remain sustainable.

 

Dunsborough Artificial Reef

In January of 2013 the first purpose-built artificial reef in Western Australia was unveiled by the Minister for Fisheries. The $2.38 million investment saw the establishment the State’s first artificial reef trial on the South West coast off Bunbury and Dunsborough, with an aim to increase habitat for key fish species. Royalties for Regions program funding and $520,000 from recreational licencing revenue enabled the artificial reef initiative to come to fruition.

Purpose-built reef modules are designed to create upwelling’s bringing nutrient rich water from the sea floor to the surface creating phytoplankton and zooplankton blooms.  These booms provide the basis for productive food chains and Recfishwest believes artificial reefs create new habitat and nursery areas.

The reef location is within five kilometres of shore almost directly in line with existing boat ramps. These reefs will enable safe access for recreational fishers with small boats in Geographe Bay.

The structures will benefit the environment and local communities; complement Western Australia’s robust and adaptive fisheries’ management approach; and help ensure fish stocks remain sustainable.

Bunbury Artificial Reef

In January of 2013 the first purpose-built artificial reef in Western Australia was unveiled by the Minister for Fisheries. The $2.38 million investment saw the establishment the State’s first artificial reef trial on the South West coast off Bunbury and Dunsborough, with an aim to increase habitat for key fish species. Royalties for Regions program funding and $520,000 from recreational licencing revenue enabled the artificial reef initiative to come to fruition.

Purpose-built reef modules are designed to create upwelling’s bringing nutrient rich water from the sea floor to the surface creating phytoplankton and zooplankton blooms.  These booms provide the basis for productive food chains and Recfishwest believes artificial reefs create new habitat and nursery areas.

The reef location is within five kilometres of shore almost directly in line with existing boat ramps. These reefs will enable safe access for recreational fishers with small boats in Geographe Bay.

The structures will benefit the environment and local communities; complement Western Australia’s robust and adaptive fisheries’ management approach; and help ensure fish stocks remain sustainable.

Mandurah Artificial Reef

The Mandurah artificial reef was deployed off the coast of Mandurah in April 2016. The Mandurah artificial reef is constructed out of the same purpose-built modules as the South West Artificial Reefs.  Being deployed at a similar depth as the South West Reefs, the new reef will share a similar level of success.  The modules were deployed by a crane barge around 9km from Dawesville Cut and 1km from Five Fathom Bank in a depth range of 24-28m.

The purpose-built reef consists of 30 cubic reinforced concrete modules, arranged in clusters of five modules. Each module is 3m x 3m x 3m, weighs 10 tonnes, has a surface area of 30m2 and has an internal volume of 27m3.

The module design is the same as those used in the Bunbury and Dunsborough artificial reefs, being a hollow cube with curved cross braces. The design is aimed to promote upwelling (bringing nutrient rich water from the sea floor to the surface creating phytoplankton and zooplankton blooms, providing the basis for productive food chains) as well as create varied complex spaces and habitats which act as shelter for fish.

With the same modules in a similar depth to the successful South West artificial reefs, the Mandurah Artificial Reef is already developing into a complex marine habitat supporting a diverse fish community providing fishing opportunities for iconic species such as Pink Snapper, Skippy, Dhufish, Baldchin Groper and Samson Fish.  Prior to the deployment of the Dunsborough and Bunbury artificial reefs only a dozen fish species were identified at the deployment locations. Three years later over 60 species have called these reefs home.  As the Mandurah reef has been constructed from the same modules and placed in a similar depths we are confident the Mandurah reef will experience the same success.

The deployment of the reefs was the last stage of a long community driven process to get the reefs in the water. Both Port Bouvard Recreation and Sporting Club as well as the Mandurah Offshore Fishing and Sailing Club (MOFSC) consulted with Recfishwest on reef locations with volunteers from MOFSC even dropping cameras to the seafloor to find the ideal site characteristics for the reef.

The Mandurah Artificial Reef is Australian made with the modules being designed by an Australian company called the Haejoo Group, built in WA at MJB industries in Australind, deployed by Perth based company Subcon Ptyltd who used staff and vessels from Total AMS.

Perth Metro Fish Towers

Fishing for Perth metro pelagics has a new breath of new life with the instalment of two steel reef towers, which will boost fishing opportunities for fishers. The towers are an addition to the numerous other artificial reef and habitat enhancement projects complete or underway in WA, funded through recreational fishing licence fees.

The reef towers differ from the concrete reef modules currently installed off Dunsborough, Bunbury and Mandurah and those planned for deployment in Esperance, Exmouth and Dampier. The towers are the first steel artificial reef structures in WA, with a different layout and construction to the demersal reefs, and on a much larger vertical scale. Designed by Western Australian artificial reef specialists, Subcon, the purpose built reefs are an impressive 12.5m high or the same size as a four storey building!

To add to its height, each reef weighs a massive 70 ton and is 10m long and 7.8m wide. The costly process of reef deployment at sea was also reduced through a new innovative technique that has never been used with this style of artificial reef anywhere in the world. Instead of being loaded onto a barge and lowered using a crane, the large structure was towed out into position and its buoyancy tanks were flooded to safely and cost effectively sink the towers.

he reef towers were specifically designed to not only house demersal fish species but namely to attract an array of pelagic top-water fish in a similar way to FADs. The lattice-like steel upper part of the reef will provide structure and concentrate small baitfish, attracting predatory pelagics. The purpose built design will also allow demersal species to shelter amongst the large base structure with its various shapes, crevasses and vertical profile.

The steel lattice structure provides a complex habitat with variations in temperature, shade and hydrological effects such as current. The curved steel plates on the tower promote upwelling and the surfaces of the structure can be colonised by macro-algae, sponges and corals to favour a variety of different species and higher abundances of fish.

The wide range of habitats influenced by the reef towers will hold a good variety of fish species, with pelagics such as Samson Fish, Yellowtail Kingfish, Salmon, Spanish Mackerel and Tuna all expected to turn up at the reef as well as demersal species such as Pink Snapper, Dhufish and Baldchin Groper. There’s also a good chance of King George Whiting, Skippy, Flathead, Flounder and even Mulloway that are caught in the surrounding areas. All of these species have been encountered on the established South West artificial reefs but other species such as Yellowfin Tuna and Bonito are also expected to make an appearance.

The reef towers were funded using recreational fishing licence fees and are for all recreational fishers to enjoy. Anchoring right on top of reefs should be avoided as it will limit the benefit they can have to all fishers and the chances of your anchor returning. Similar to the South West artificial reefs, some of the best fish are caught around the structure, not right on top of it. Fish can be targeted by casting or trolling around the area and over the top of the reef as well as drifting near the reef location and jigging or drifting weighed baits in a burley trail.

The reef towers are located in “the paddock” between Garden Island and Rottnest Island. The final coordinates have been given as 32ᵒ 07.527′ S, 115ᵒ 27.013′ E for Tower 1 and 32ᵒ 07.461′ S, 115ᵒ 26.978′ E for Tower 2 in 44-45m water depth.

Upcoming Artificial Reefs in WA

Funding has already been announced (December 2016) for three more Artificial Reefs to be designed and installed in regional WA waters.

The towns of Esperance, Exmouth and Karratha will receive new Artificial Reefs in the coming years.

In Exmouth, the concept is construction of a reef close to public boat ramp amenities, namely the Exmouth Marina but not within the Kailis fishery, in the 10 – 12 m mark north of the Exmouth Marina that is accessible for everyone and will also have benefits to the areas adjacent to the proposed site.

Further to above, the Esperance reef will be installation near Low Rock, in 20m of water depth and at a proposed location approximately 5km from the Bandy Creek boat ramp. The aim of the Esperance Reef installation is to offer access to reliable fishing structures in the vicinity of the mouth of Bandy Creek Boat Harbour.

As with other artificial reef projects, the reduced fishing pressure on natural reef structures is also seen as a major benefit to the areas adjacent to the proposed site.