scholarly journals Assessment of the Performance of an Artificial Reef Made of Modular Elements through Small Scale Experiments

2021 ◽  
Vol 9 (2) ◽  
pp. 130
Author(s):  
Dea Cardenas-Rojas ◽  
Edgar Mendoza ◽  
Mireille Escudero ◽  
Manuel Verduzco-Zapata
Keyword(s):  
Artificial Reef ◽  
Artificial Reefs ◽  
Small Scale ◽  
Beach Profile ◽  
Transmission Coefficients ◽  
Wave Flume ◽  
Ecological Performance ◽  
Limited Success ◽  
Hydrodynamic Function ◽  
Natural Reefs

Artificial reefs have proven to be an optimal and effective solution in stabilizing coastlines around the world. They are submerged structures that imitate the protection service provided by natural reefs accomplishing the functions of dissipating wave energy and protecting beach morphology, but also being an ecological solution. In this paper, 2D small-scale experiments were performed to analyze the hydrodynamic, morphological, and ecological behavior of an artificial reef constructed of modular elements. Two typical beach-dune profiles were constructed in a wave flume over which two locations of an artificial reef were tested. From these tests, transmission coefficients were obtained as well as the beach profile response to the presence of the artificial reef. These results are used to discuss about the hydrodynamic, morphological, and ecological performance of the artificial reef. The proposed artificial reef showed good morphological performance while its hydrodynamic function had limited success. In turn, the ecologic performance was theoretically addressed.

The influence of an offshore artificial reef on the abundance of fish in the surrounding pelagic environment

2015 ◽  
Vol 66 (5) ◽  
pp. 429 ◽  
Author(s):  
Molly E. Scott ◽  
James A. Smith ◽  
Michael B. Lowry ◽  
Matthew D. Taylor ◽  
Iain M. Suthers
Keyword(s):  
Artificial Reef ◽  
Management Tool ◽  
Small Scale ◽  
Pelagic Environment ◽  
Significant Difference ◽  
Small Scale Effect ◽  
Total Fish ◽  
Seriola Lalandi ◽  
Natural Reefs ◽  
Sydney Australia

Artificial reefs are a popular fisheries management tool, but the effect of these reefs on the abundance of fish in the surrounding pelagic environment is uncertain. Pelagic baited remote underwater video (PBRUV) was used to observe the fish assemblage surrounding an offshore artificial reef (OAR), near Sydney, Australia. PBRUVs were deployed at three distances (30, 100, 500m) from the OAR, and compared with a drop camera deployed directly over the OAR. There was a significantly greater abundance of fish on the OAR, but no significant difference in abundance at the 30-, 100- or 500-m distances. Two highly mobile non-resident species (Seriola lalandi, Pseudocaranx dentex) were significantly more abundant on the OAR, but this association was not detected 30m away. The lack of a significant difference in total fish abundance, or in assemblage composition, between the 30-, 100- and 500-m distances suggests that any association with the OAR is on a localised scale (<30m). One exception was the ocean leatherjacket (Nelusetta ayraudi), which had an association detected 100m from the OAR. This predominantly small-scale effect may be influenced by the proximity of this OAR to numerous natural reefs.

Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

2018 ◽  
Keyword(s):  
Reef Fish ◽  
Juvenile Fish ◽  
Artificial Reef ◽  
Reef Fishes ◽  
Artificial Reefs ◽  
Fine Sediments ◽  
Management Objectives ◽  
Continental Shelves ◽  
Fractal Characteristics ◽  
Natural Reefs

<em>Abstract</em>.—This paper focuses on interactions between reefs, fisheries, and their management and discusses the relationship between reef fish and their habitat. Hard bottom is much less extensive than fine sediments on most continental shelves but supports epifauna/flora as cover for reef fish and serves as habitat for their prey species. Corals, epifauna, and macroflora on natural reefs function as feeding, shelter, and aggregation sites and often have fractal characteristics. Size frequencies of catches from unfished banks may reflect the aggregate of crevice size spectra present, and this influences growth and natural mortality rates at size. It is suggested that migration is initiated when juvenile fish outgrow cover in nursery areas, which only offered predator protection at smaller sizes. Juveniles are then forced to move further offshore where cover for protecting larger reef fishes is often more available. Large cavities are rare on most natural outcrops or reefs, but these attract large fish and artificial reefs are often designed to have large cavities needed by mature reef fishes. Once artificial reefs are located by fishermen, large, resident fishes are readily captured. Unless some offshore reefs or refugia are protected, spawning potential could be affected.

scholarly journals Using ecological evidence to refine approaches to deploying offshore artificial reefs for recreational fisheries

2021 ◽  
Author(s):  
Craig Blount ◽  
Valeriya Komyakova ◽  
Lachlan Barnes ◽  
Marcus Lincoln Smith ◽  
Dilys Zhang ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Artificial Reef ◽  
Artificial Reefs ◽  
Recreational Fisheries ◽  
Fishing Activity ◽  
Ecological Literature ◽  
Optimal Shapes ◽  
Natural Reef ◽  
Quantitative Indicators ◽  
Natural Reefs

Artificial reefs have many applications but are best known for their deployments to enhance recreational fisheries by creating new habitat in areas where natural reef is otherwise limited. The expectation is that fish assemblages will take up residence on artificial reefs and that these assemblages will become at least similar, if not more diverse and abundant, to those on natural reefs. Although designed, purpose-built artificial reefs are becoming more widely used in support of recreational fisheries and many of the historic issues have been resolved, conservation practitioners and managers still face challenges as to the type, number, and arrangement of structures and where to deploy them to maximize benefits and minimize risks. The ecological literature was reviewed to develop and enhance contemporary principles of artificial reef best practices for utilization. Our review identified optimal shapes, vertical relief, void spaces, and unit arrangements for increasing volumes and diversity of catch to recreational fishers and we provide a tool for identifying the least constrained areas for artificial reef deployment. We suggest; (a) monitoring of noncatch motivators in combination with quantitative indicators of the fishing activity (e.g., catch rate and effort) will provide the best understanding of success or failure of an artificial reef deployment; (b) choosing target species for informing purpose-built artificial reef designs to be reef-associated, demersal, philopatric, territorial, and obligatory reef species that are desired by local recreational fishers; and (c) considering the ecosystem services provided by artificial reefs beyond those associated with recreational fishing.

Monitoring of reef associated and pelagic fish communities on Australia’s first purpose built offshore artificial reef

2016 ◽  
Vol 74 (1) ◽  
pp. 277-285 ◽  
Author(s):  
Alistair Becker ◽  
Matthew D. Taylor ◽  
Michael B. Lowry
Keyword(s):  
Fish Assemblage ◽  
Monitoring Program ◽  
Artificial Reef ◽  
Integrated Approach ◽  
Artificial Reefs ◽  
Fish Length ◽  
Reef Fish Assemblage ◽  
Length Data ◽  
Natural Reefs ◽  
Term Monitoring

Artificial reefs now form part of an integrated approach to enhance fisheries around the world. A responsible approach to artificial reef deployment calls for clear, well defined goals prior to any reef being placed in the field, followed by subsequent monitoring to assess whether these goals are being achieved. In this study, to evaluate if an artificial reef off Sydney was meeting its goal of providing quality fishing opportunities through the establishment of a complex fish assemblage, a 4-year monitoring program was designed. This program examined the response of reef-associated and pelagic fishes to the deployment of a purpose built offshore reef, relative to control reefs. Fish were observed immediately following deployment, but the artificial reef fish assemblage remained distinct from the three natural control reefs throughout the monitoring period. Also, the artificial reef displayed inter-annual variability associated with successional processes, which was not evident on the natural reefs. Fish length data indicated that the artificial reef was providing resources for both juvenile and adults of a number of species. This study demonstrates artificial reefs can provide habitats for a diverse group of fish, but the assemblages are unlikely to mimic those on natural reefs. We have also shown that longer term monitoring periods, covering multiple years are required to gain a robust understanding of the response of fish to reef deployment. This information can be used to understand the benefits and limitations of future artificial reef deployments.

Sediment transport modifications induced by submerged artificial reef systems: a case study for the Gulf of Venice

2014 ◽  
Vol 43 (1) ◽  
Author(s):  
Davide Bonaldo ◽  
Alvise Benetazzo ◽  
Andrea Bergamasco ◽  
Francesco Falcieri ◽  
Sandro Carniel ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Coastal Zone Management ◽  
Artificial Reef ◽  
Sediment Concentration ◽  
Quantitative Information ◽  
Small Scale ◽  
Zone Management ◽  
Basin Scale ◽  
Scale Modelling ◽  
Maritime Spatial Planning

AbstractThe shallow, gently sloping, sandy-silty seabed of the Venetian coast (Italy) is studded by a number of outcropping rocky systems of different size encouraging the development of peculiar zoobenthic biocenoses with considerably higher biodiversity indexes compared to neighbouring areas. In order to protect and enhance the growth of settling communities, artificial monolithic reefs were deployed close to the most important formations, providing further nesting sites and mechanical hindrance to illegal trawl fishing.In this framework, a multi-step and multi-scale numerical modelling activity was carried out to predict the perturbations induced by the presence of artificial structures on sediment transport over the outcroppings and their implications on turbidity and water quality. After having characterized wave and current circulation climate at the sub-basin scale over a reference year, a set of small scale simulations was carried out to describe the effects of a single monolith under different geometries and hydrodynamic forcings, encompassing the conditions likely occurring at the study sites. A dedicated tool was then developed to compose the information contained in the small-scale database into realistic deployment configurations, and applied in four protected outcroppings identified as test sites. With reference to these cases, under current meteomarine climate the application highlighted a small and localised increase in suspended sediment concentration, suggesting that the implemented deployment strategy is not likely to produce harmful effects on turbidity close to the outcroppings.In a broader context, the activity is oriented at the tuning of a flexible instrument for supporting the decision-making process in benthic environments of outstanding environmental relevance, especially in the Integrated Coastal Zone Management or Maritime Spatial Planning applications. The dissemination of sub-basin scale modelling results via the THREDDS Data Server, together with an user-friendly software for composing single-monolith runs and a graphical interface for exploring the available data, significantly improves the quantitative information collection and sharing among scientists, stakeholders and policy-makers.

Small-scale fishery income impact from artificial reefs in Lang Suan District, Chumphon Province, Thailand

2018 ◽  
Vol 21 (3) ◽  
pp. 1519-1531
Author(s):  
Rapeepan Kantavichai ◽  
Thamrong Mekhora ◽  
Monthon Ganmanee ◽  
Ariya Thongsamui ◽  
Maytapon Pornratanachotsakul
Keyword(s):  
Artificial Reefs ◽  
Small Scale

scholarly journals REDUCTION OF WAVE OVERTOPPING RATE BY THE USE OF ARTIFICIAL REEFS

1988 ◽  
Vol 1 (21) ◽  
pp. 23
Author(s):  
Toru Sawaragi ◽  
Ichiro Deguchi ◽  
San-Kil Park
Keyword(s):  
Wave Breaking ◽  
Artificial Reef ◽  
Numerical Procedure ◽  
Artificial Reefs ◽  
Irregular Waves ◽  
Analysis Method ◽  
Wave Analysis ◽  
Wave Overtopping ◽  
Unidirectional Flow ◽  
Individual Wave

A wave overtopping rate from a sea dike of various toe depths is formulated based on a weir model in an unidirectional flow. To evaluated the wave overtopping rate from a seadike on an artificial reef by the weir model, a numerical procedure for predicting wave transformations including the effect of forced wave breaking on the reef is constructed. After confirming the applicability of the model through experiments with regular and irregular waves, the effect of artificial reef on wave overtopping is discussed. So-called individual wave analysis method is shown to he applicable to the wave overtopping caused by irregular waves.

scholarly journals The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs

2009 ◽  
Vol 66 (4) ◽  
pp. 691-698 ◽  
Author(s):  
W. R. Hunter ◽  
M. D. J. Sayer
Keyword(s):  
Habitat Complexity ◽  
Artificial Reef ◽  
Structural Complexity ◽  
Marine Species ◽  
Rocky Reef ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Concrete Blocks ◽  
Belt Transect ◽  
Natural Reefs

Abstract Hunter, W. R., and Sayer, M. D. J. 2009. The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs. – ICES Journal of Marine Science, 66: 691–698. Several north temperate marine species were recorded on subtidal hard-substratum reef sites selected to produce a gradient of structural complexity. The study employed an established scuba-based census method, the belt transect. The three types of reef examined, with a measured gradient of increasing structural complexity, were natural rocky reef, artificial reef constructed of solid concrete blocks, and artificial reef made of concrete blocks with voids. Surveys were undertaken monthly over a calendar year using randomly placed fixed rope transects. For a number of conspicuous species of fish and invertebrates, significant differences were found between the levels of habitat complexity and abundance. Overall abundance for many of the species examined was 2–3 times higher on the complex artificial habitats than on simple artificial or natural reef habitats. The enhanced habitat availability produced by the increased structural complexity delivered through specifically designed artificial reefs may have the potential to augment faunal abundance while promoting species diversity.

Dispersal of yellowtail kingfish (Seriola lalandi) from a coastal embayment following a recreational fisheries enhancement stocking program: attempts to integrate aquaculture and habitat-based initiatives

2021 ◽  
Author(s):  
Alistair Becker ◽  
Michael B Lowry ◽  
D Stewart Fielder ◽  
Matthew D Taylor
Keyword(s):  
Artificial Reef ◽  
Artificial Reefs ◽  
Recreational Fisheries ◽  
Dispersal Patterns ◽  
The North ◽  
Sea Ranching ◽  
In The Wild ◽  
Yellowtail Kingfish ◽  
Seriola Lalandi ◽  
Fisheries Enhancement

Fisheries enhancement initiatives including marine stocking and artificial reef deployments are becoming increasingly common in many parts of the world. Combining the two by releasing hatchery reared fish onto artificial reefs is used in sea-ranching operations but is an approach rarely adopted for recreational fisheries. Yellowtail kingfish (Seriola lalandi) form a valuable recreational fishery in Australia and in 2018 a pilot stocking program was initiated to enhance this fishery. Fish were released onto estuarine artificial reefs in Botany Bay to evaluate if estuarine artificial reefs are suitable release habitat for juvenile yellowtail kingfish and to monitor their dispersal patterns using acoustic telemetry and a tag-recapture program. Both approaches showed similar patterns, indicating juvenile yellowtail kingfish rapidly dispersed from the release location and can travel at least 60 km during their first weeks in the wild. Twenty percent of the acoustically tagged fish entered nearby estuaries to the north and south and tagged fish were also recaptured in these estuaries, indicating that the estuaries provide habitat for juveniles. There was little interaction between stocked fish and two large coastal artificial reefs positioned near Botany Bay. Stocked yellowtail kingfish will likely disperse rapidly from release locations which is consistent with their pelagic life history. While this may present challenges to fisheries managers, increasing release numbers to maintain stocking densities over a broader area may provide a solution. Future releases of fish on coastal natural and artificial reefs are an important next step in refining stocking practices for this species and will help further identify key juvenile habitats.

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