Concrete Artificial Reef Research Articles

The impact of multi-type artificial reef habitats on the feeding ecology and trophic niche of dominant rocky reef fish species (Hexagrammos otakii and Sebastes schlegelii)

Large-scale artificial reef constructions have been carried out in the coast of northern Yellow Sea, which has effectively enhanced populations of rocky reef fish species. However, there is a lack of evidence regarding the differences in community composition among different types of artificial reef habitats. This study scrutinizes the foraging dynamics and ecological niche partitioning of Hexagrammos otakii and Sebastes schlegelii, which are two representative rocky reef fish species in the northern Yellow Sea. Stomach content analysis indicates that H. otakii exhibits a more diverse diet compared to S. schlegelii, with both species achieving the highest dietary diversity within concrete reef habitats. When factoring in body size, the dietary diversity for fish in the 0–15 cm size class was found to be the greatest within rock reef habitat, while larger individuals exhibited higher diversity within ship artificial reef habitats. The prey composition results demonstrate spatial differentiation patterns consistent across all size classes, with these discrepancies predominantly situated between ship and concrete or rock artificial reef habitats. The taxa driving these differences varied with fish species and body size, encompassing various prey categories such as Decapoda, Teleost, Polychaeta and Amphipod. Findings from the Stable Isotope Mixing Model (SIMMR) revealed significant dietary variations linked to species, habitat type and size class, which were fundamentally in agreement with the stomach content analysis. Niche analysis disclosed that overall niche breadth for both fish populations was largest in concrete artificial reef habitat. This suggests that each reef type caters to specific fish size classes, showcasing distinct spatial and interspecific variations in foraging tactics.

Preliminary investigation and life cycle assessment of artificial reefs with recycled brick-concrete aggregates

An economical and environment-friendly artificial reef concrete using fully recycled brick-concrete aggregate as raw material was proposed. This study investigates the mechanical properties, drying shrinkage, chloride ion penetration, and biological adaptability of the reef. A comparative analysis is conducted on the environmental impacts (EI), carbon emission impact and cost efficiency of artificial reefs, considering natural aggregate concrete and recycled brick-concrete aggregate concrete at the material level. The results indicate that the use of recycled brick-concrete aggregates can achieve service performance equivalent to that of natural aggregates. Field investigations involving samples immersed in seawater for six months reveal the positive trapping effects of recycled materials on aquatic organisms. The Life Cycle Assessment (LCA) results reveal that achieving a 100 % replacement rate of recycled brick concrete aggregate (RBCA) creates a positive feedback loop for carbon emissions when appropriately incorporating industrial waste materials like fly ash and silica fume. In comparison to ordinary concrete, the utilization of recycled materials can significantly reduce construction costs, up to 63.7 %, thereby presenting notable economic advantages.

Corrigendum to “Pre-study of the evaluation of ecological sessile succession and their relationship with bacteria on concrete artificial reef material” [International Journal of Environment and Geoinformatics 11(1), 30-35 (2024)

There was a need to correct the errors in chemical oceanography in the findings of Gül and Ünsal's (2024) study, which was about the ecological succession on the concrete artificial reef material in the Heybeliada artificial reef area and its relationship with bacteria.

Pre-study of the evaluation of ecological sessile succession and their relationship with bacteria on concrete artificial reef material

Artificial reefs are human-made structures built for promoting marine life. Long-term monitoring and research regarding the use of artificial reefs in terms of ecological and economic perspective is essential. In this study, the ecological succession and their relationship with bacteria on concrete artificial reef material was investigated. Heybeliada artificial reef site was selected as sampling area. After three years period, the visual examination of ecological succession and sessile marine bacteria count were performed on the concrete artificial reef material. All the results showed that the strength of the artificial reef material is also affected by the biofilm layer and the creatures in the microecosystem. Therefore, monitoring studies should be carried out to determine the service life of artificial reef materials as well as to reveal the existence of the ecosystem formed and developing in these areas qualitatively and quantitatively.

Sustainable oyster shell incorporated artificial reef concrete for living shorelines

An innovative pervious concrete containing recycled oyster shells for artificial reef structures has been developed. The new artificial reef concrete incorporating oyster shells contained higher amounts of supplementary cementitious material and sea sand instead of river sand. Investigations on homogeneity, strength characteristics, pH levels and mussel larvae (Mytilus galloprovincialis) settlement were performed to verify the effectiveness of different constituents. The proposed concrete mixes have the potential for use in artificial reef construction representing improved characteristics with regards to weight, cost, environmental sustainability, carbon footprint and attachment of shellfish larvae to the reef, enabling nature-based coastal protection solutions, or ‘living shorelines.

Response mechanism of meiofaunal communities to multi-type of artificial reef habitats from the perspective of high-throughput sequencing technology

Multiple types of artificial reefs have been widely deployed in the coast of northern Yellow Sea, which can enhance fishery resources, restore coastal habitats and improve the marine environment. Meiofauna plays important ecological roles in marine ecosystem, but the response mechanism of meiofaunal community to different types of artificial reef is still poorly understood. In this study, we characterized the meiofaunal communities of concrete artificial reef habitat (CAR), rocky artificial reef habitat (RAR), ship artificial reef habitat (SAR) and adjacent natural habitat (NH) using 18S rRNA gene high-throughput sequencing technology, and explored the relationship of community-environment. The results showed that the diversity and community structure of meiofauna differed significantly on both spatial and temporal scales. Spatial differences were mainly contributed to the flow field effects and biological effects generated by artificial habitats, while temporal differences were driven by temperature (T) and dissolved oxygen (DO). The dominant taxa of meiofauna included arthropods, annelids, platyhelminths and nematodes. Platyhelminths were mainly positively influenced by artificial habitats but annelids were the opposite. Co-occurrence network analysis revealed that NH was more sensitive to environmental change than artificial habitat, while the performance of CAR and SAR were more stable. These results indicated that meiofauna can respond accordingly to different types of artificial habitats, and could be superimposed over the normal seasonal effects. The current study could provide fundamental data for understanding the response mechanism of meiofaunal community to different types of artificial habitats and a reference for assessments of the impact of artificial reefs on the marine environment.

Scleractinian recruits on natural and artificial substrates in temporary sediment-challenged coastal water of Bangkalan, Madura Island, Indonesia

Recruitment of coral juveniles could serve as indicator for potential of coral reef recovery and is a critical process in supporting population as well as facilitating recovery after event of disturbance. However, sediments suspended in the water column and settling on to reef surface can negatively influence the distributions and abundances of reef-building corals, including altering the settlement patterns and survival of coral larvae and new recruits. In this study, we compared the density and diversity of Scleractinian recruits on natural substrate and artificial reef (made of concrete; 2 years after deployment) in the relatively turbid water of Sepulu coastal water, Bangkalan – Madura Island, East Java. Observation of stony coral recruits were conducted in-situ at depth of 3-4 meter in two locations. At the end of the study, we identified 18 species of Scleractinians from 10 genera and 7 families; dominated by Goniopora (F. Poritidae), Galaxea (F. Euphyllidae) and Goniastrea (F. Merulinidae). There was no difference in term of species richness and composition among locations and type of substrate. However, in both locations, more recruits grown in concrete artificial reef (15.2±2.61 - 18.3±2.91 unit/m2) compared to natural substrate (4±1.25 - 4.1±1.29 unit/m2), respectively. These findings suggest that concrete artificial reef is applicable for coral reef restoration and rehabilitation in temporary turbid coastal water by providing suitable substrate for larval recruitments.

Evaluation of artificial reef habitats as reconstruction or enhancement tools of benthic fish communities in northern Yellow Sea

Artificial reefs have been widely deployed in the northern Yellow Sea. However, the differences in the ecological benefits on different types of artificial reef habitats are still poorly understood. In this study, the temporal and spatial differences on benthic fish communities were evaluated among concrete artificial reef habitat (CAR), rocky artificial reef habitat (RAR), ship artificial reef habitat (SAR) around Xiaoshi Island in northern Yellow Sea. The results indicated that all three types of artificial reef habitats can enhance the diversity variables of benthic fish communities, and fish abundance, species richness and Shannon-Wiener index of CAR were generally better than the other two. CAR and RAR hosted similar community composition of benthic fish, and all types of habitats showed significant differences in community composition between winter-spring and summer-autumn. Environmental factors, especially water temperature, can also affect the community composition by affecting the migration of temperature-preferred species. Overall, the enhancement effects of artificial habitats on fisheries productivity varied with fish species and reef types. This study will help to understand the ecological effects of different types of artificial reefs in northern Yellow Sea, and then could give an insight for scientific construction of artificial reefs in this region.

Komposisi Jenis dan Keanekaragaman Ikan Karang pada 3 Jenis Bahan Terumbu Karang Buatan (Artificial reef) yang Berbeda (Beton, Ban Bekas, dan Besi) di Teluk Jemeluk Amed, Karangasem, Bali

Artificial reef at Jemeluk Bay, Karangasem, Bali is one of the area’s fisheries potential. Artificial reef is an underwater structure that is made for fishes’ protection and feeding ground. The purpose of this research is to know and understand types of reef fishes that surround the artificial reef, as well as the artificial reef’s affect onto the fish’s abundance at Jemeluk Bay. The method used for reef fish monitoring by visual census at artificial reef made from concrete, rubber tire and steel. This research is done towards six coral reef structures to get the reef fishes composition, which is made out of 7 fish families, 17 species, with an abundance total of 708 individuals. The highest fish abundance was founded at the 2nd rubber tire artificial reef with 6,4 individuals/m2, and the lowest fish abundance was found at the 1st concrete artificial reef with 3,28 individuals/m2. From the calculation at six of the artificial reef structures, the diversity index varies between 1,2 – 1,57, which is categorized as low diversity. The diversity value shows that steel artificial reef have the highest fish species diversity, however is still categorized as low.

Istakoz (Homarus gammarus Linnaeus 1758) türüne özel yapay resif modelleri

The objective of this study is to determine the possible artificial reef models preferred by lobster species (Homarus gammarus Linnaeus, 1758). For this purpose, eight artificial reef models at different shapes and sizes have been designed. These models include flat, grilled, U-type, cowl, fireplace chimney brick shapes made from the materials of wood, concrete and metal. Artificial reefs were deployed at 5, 10, 20 m water depths and 500 m from the shore on the coast of Erdek Ocaklar Bay in Marmara Sea. Then, monthly monitoring was conducted and SCUBA equipment were used during underwater monitoring. The time for deploying artificial reefs on the sea bottom (effort) was 233 minutes/diver and the time spent underwater by the divers was calculated as 540 minutes/diver. As a result of the study, 32 individuals of H. gammarus were observed in/around the artificial reefs. A significant increase was observed in the number of lobsters when the temperature dropped below 14°C. However, it was determined that lobster individuals preferred only concrete artificial reef models at the depth of 20 m. In addition, it was observed that small individuals preferred 40×80 cm flat concrete model (24 individuals) and large individuals preferred U-type concrete model (8 individuals). Therefore, it has been proposed to the usage of concrete artificial reef models in order to protect and ensure the sustainability of the reared lobster stocks and to release them into these artificial reefs while introducing them to the natural environments. In this context, this study will shed light on future studies.

Steel rebar corrosion in artificial reef concrete with sulphoaluminate cement, sea water and marine sand

To reduce the surface alkalinity of artificial reef concrete (ARC) and save fresh water and natural aggregate resources, a new artificial reef concrete (NARC) made with sulphoaluminate cement (SAC), sea water and marine sand was proposed in our previous work. However, the steel corrosion as a major concern associated with NARC has not been explored. In this paper, the effects of cement type (SAC, ordinary Portland cement (OPC), mixed cement of OPC and SAC) on the chloride permeability and capillary water absorption of sea water and marine sand-based ARCs were studied. The anodic polarization and loss of steel rebar weight were used to evaluate the effects of the cement type and corrosion inhibitor on the corrosion of steel rebars in ARCs. The results of the present work show that for sea water and marine sand-based ARC, SAC significantly improves the microstructure and decreases the chloride penetration and the water absorption rate. Meanwhile, due to the high chloride binding rate of SAC, the corrosion degree of rebars in NARC is less than that of sea water and marine sand-based ARC with OPC and mix cement of OPC and SAC. Compared with ordinary ARC (ARC made OPC, fresh water and river sand), the steel rebar corrosion in NARC is more serious. Nevertheless, a 2% dosage of corrosion inhibitor (TEA) can significantly decrease the steel rebar corrosion in NARC to a similar corrosion degree of ordinary ARC. The feasibility of using marine sand and seawater in SAC-based ARC is verified.

Short Communication: Growth rate of Acropora muricata coral fragments transplanted on dome-shaped concrete artificial reef with different composition

Abstract. Artificial reefs are artificial habitats laid in waters by mimicking some of the characteristics of natural reefs; and could be made of different materials, one of which is concrete. Seashell waste and stone ash could be added as an alternative material to the concrete for artificial reefs. The purpose of this research is to access the growth rate of Acropora muricata coral fragments transplanted on the hollow dome-shaped concrete with three different compositions: C1), conventional concrete, composed by a mixture of Portland cement, sand, and gravel (composition was 1:3:2); C2), a mixture of Portland cement, sand and crushed bivalve's shells (composition was 1:3:2); and C3), a mixture of Portland cement, stone waste (stone dust), sand and crushed bivalve's shells (composition was 1:3:3:2). Observation of coral fragment growth was conducted underwater by Scuba diving for 6 months with observed parameters were fragment length, colony diameter and number of branching. The highest rate of fragment lengthening of A. muricata coral fragment was at C2 (1.019±0.081 cm/month) and C1 (1.014±0.076 cm/ month). The highest colony diameter increment was also in C2 (1.903±0.212 cm/month) and C1 (1.856±0.219 cm/month); while largest number of branches was also in C2 (13.31 or 2.21 branch/month) and C1 (12.56 or 2.09 branch/month), respectively. Based on one-way ANOVA and Tukey's HSD test (p = 0.05), there is no significant difference in fragment lengthening and colony diameter in C1 and C2 model, yet differed significantly with C3 model.

Preliminary investigation of artificial reef concrete with sulphoaluminate cement, marine sand and sea water

To promote the extensive application of artificial reefs, developing a type of economical and low-alkaline artificial reef concrete (ARC) where marine organisms can grow quickly is necessary. A grade C30 ARC with sulphoaluminate cement (SAC), sea water and marine sand is proposed. The workability, mechanical properties, surface pH and microstructure (scanning electron microscopy (SEM), X-ray diffraction (XRD) and pore structure) of this ARC were studied. The influences of the cement type (ordinary Portland cement (OPC), SAC and a mixed SAC and OPC cement), water type (freshwater and sea water) and sand type (river sand and marine sand) on the properties of ARC are discussed. In terms of the mechanical properties and surface pH of ARC with sea water and marine sand, SAC performed better than OPC. However, a mixed SAC and OPC cement had significantly negative effects on the workability and mechanical properties of the sea water and marine sand-based ARC. Marine sand and sea water displayed positive effects on the mechanical properties but no obvious effects on the surface pH of SAC-based ARC. Compared to ARC with OPC, river sand and freshwater, the proposed ARC has superior mechanical properties, a better microstructure, a lower surface pH and a lower cost.

Evaluating feasibility of using sea water curing for green artificial reef concrete

Sea water curing (SWC, 20 ± 2 °C) has been proposed to obtain economic benefits for green artificial reef concrete (GARC) in coastal areas. This study evaluated the feasibility of SWC based on the mechanical properties and permeability resistance of GARC. Three curing regimes were used: SWC (20 ± 2 °C), standard curing (SC, 90–95% relative humidity at 20 ± 2 °C), and fresh water curing (FWC, 20 ± 2 °C). The results showed that there were little effects on compressive strength and splitting tensile strength of GARC under the three curing regimes. In addition, SWC slightly increased the permeability of GARC. SWC appeared to be an effective technique to cure GARC in marine environments, which was further confirmed by evaluating the microstructure using environmental scanning electron microscope, X-ray diffractometer, and pore structure analyzer.

Innovative Uses of Recycle Waste Materials as an Artificial Concrete Reef for Estuarine Ecosystem

This study enveloped an innovative uses of banana peel particles (BPP) incorporated with recycle aggregate concrete (RAC) from construction waste as an artificial concrete reef for estuarine ecosystem. An artificial reef concrete composites were made of using BPP reinforced RAC as a matrix. The conretes composite cube were prepared in a percentages of 10%, 20% and 30% of BPP to RAC respectively. The concrete cubes without BPP was used as control cubes. The compressive strength of an artificial reef concretes composites were carried out at 28 days. The total nutrient dispersed were determined using total nitrate (TN), phosphorus (TP) and organic carbon (TOC) test of the water samples in 6 days. The results showed that the averages compressive strength were 26.8 MPa for 10% of BPP, 18.3 MPa for 20% of BPP and 11.MPa for 30% of BPP, respectively. The amount of TN, TP and TOC leached from the articial concrete reef ranged from 34.3% to 41.5%, 58.2% to 70.3%, and 7.2% to 10.6%, respectively. It also reported that the amount of nutrients leached from an artificial reef increased gradually with time as more percentages of BPP added to concrete composites and on the contrary, the compressive strength indicated decreases with the increased of BPP. Wet can be concluded that, BPP from the agriculture wastes could be used as potential nutrient sources of nitrogen, phosphorus and organic carbon for an artificial concrete reef in estuarine ecosystem with some further study on mechanical properties to increase the compressive strength of an artificial reef composite concretes.

Biogenic sulfuric acid corrosion resistance of new artificial reef concrete

Through biogenic sulfuric acid attack on concrete, comparisons between ordinary Portland cement concrete (OPCC) and new artificial reef concrete (NARC) prepared with sulphoaluminate cement, marine sand and sea water were made. Biogenic sulfuric acid corrosion resistance was studied by analyzing the surface and localized morphology, mass loss and compressive strength of both concrete specimens. The corrosion products were investigated by environmental scanning electron microscope (ESEM), X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR). Results showed that the visually apparent corrosion degree and loss rates of mass and compressive strength are higher for OPCC than for NARC following exposure to biogenic sulfuric acid.

The Influence of Clamshell on Mechanical Properties of Non-Structure Concrete as Artificial Reef

Clamshell waste had higher chemical content of Calcium Carbonate (CaCO3) than the limestone, egg shells, ceramic, or other materials. These physical properties gave the potential for material substitution as coarse aggregate in concrete artificial reefs. In addition, the utilization of leather waste in concrete structures could function as taxis for fish in the vicinity. This study utilized two types of coarse aggregate (filler) which were crushed stone and/or clamshell waste of the blood clamshells and kurkur clamshells. The test was to identify the mechanical properties of concrete artificial reef namely: Hammer test (ASTM C805), abrasion test (ASTM C779), the pressure test (SNI 03-1974-1990), split tensile test (ASTM C496 / C496M-11), Ultrasonic Pulse Velocity (UPV) test (ASTM C597-16), Porosity test (C642-13), permeability test (SN 505 252/1). The Concrete mixing is conducted according to SNI 03-2834-2000 standard and quality standard of solid concrete brick (SNI 03-0349-1989). Before the test, the concrete soaked in fresh water and sea water and left in the open air until 28 days. The results showed that the use of clamshell waste as filler had potential as a concrete compressive strength of non-structure approaches to the quality of solid concrete brick, as artificial reef material..Â

Leaching Behaviour of Organic Materials in Reinforced Concrete Artificial Reef with RAC

This paper reports the leaching behaviour of pineapple skins incorporated in the artificial reef fabricated from recycle aggregate concrete. Pineapple skin was mixed with the concrete as added material which produce nutrients to attract fish habitat. Material test was conducted on the concrete reef specimens to determine its compressive strength. The nutrients dispersed were measured by using total phosphorus and nitrate test of the water sample collected from each of the artificial reef within the six days duration. Results showed the compression strength of the reef decreased with the increase of percentage pineapple skin used. However, it was found that the total phosphorus and nitrate leached from the reef increased gradually with time as the percentage of pineapple skin used increased.

On the use of blast furnace slag and steel slag in the preparation of green artificial reef concrete

This study is motivated by the need for the development of green artificial reef concrete (GARC) and the reuse of granulated blast furnace slag (GBFS) and steel slag (SS) from the steel manufacturers located near coastline. GARC was developed with industrial waste including GBFS, SS and flue gas desulfurization gypsum as the major raw materials. Physical properties and compressive strength development of the prepared GARC were examined. Hydration products of GARC paste were investigated through X-ray diffraction, differential scanning calorimetry and scanning electron microscope techniques. The developed GARC shows a 28-day compressive strength of 71.4MPa and a density of 2765.5kg/m3, which contains industrial waste accounting for 98% by weight of its total solid raw materials. Investigation of hydration products in GARC paste reveals that the major hydration products are ettringite and C–S–H gel with a very dense microstructure, without considerable amount of portlandite that is commonly found in traditional concrete. The absence of portlandite is favorable for lowering the pH valve of artificial reefs, which would be benefit for avoiding the accumulation of fouling organisms like barnacles on the surface of concrete artificial reefs. An experimental-scale deployment of GARC specimens in the sea preliminarily demonstrates that GARC is suitable for the attachment growth of algae. The successful development of GARC mainly composed of GBFS and SS could potentially offer great benefits in promoting the sustainable development of steel manufacturers closely located to coastline as well as fishery industry.

Workability, mechanical properties and affinity of artificial reef concrete

A new artificial reef concrete (NARC) with sulphoaluminate cement, marine sand and sea water et al. was proposed. The effect of cement type, sand type and water type on the workability (namely slump, slump loss cohesiveness, water retention), mechanical properties namely compressive strength, splitting tensile strength and dynamic elastic modulus) and affinity (namely surface initial pH value and the leaching rate of alkaline material in concrete) of concrete was studied. The microstructure of concrete was detected by X-ray diffraction, scanning electron microscope and pore structure analyzer, respectively. The studies show that NARC has superior workability, mechanical properties and affinity compared to ordinary Portland cement concrete with river sand and fresh water. Therefore, the feasibility of NARC in artificial reef is verified.