Artificial Reefs Research Articles

Using Local Scour Around Artificial Reefs to Prevent Illegal Fishing on the Northwestern Coast of South Korea

Using Local Scour Around Artificial Reefs to Prevent Illegal Fishing on the Northwestern Coast of South Korea

Residency and movement patterns of juvenile yellowfin bream Acanthopagrus australis, stocked on estuarine artificial reefs

Context Successful fish stocking relies upon releasing cohorts directly into habitat containing suitable supporting resources. To facilitate this, an emerging trend has seen fish released onto artificial reefs. Aims We compared the residency and movement patterns of juvenile sparids (yellowfin bream – Acanthopagrus australis), stocked on artificial reefs and natural habitat, to determine the suitability of incorporating artificial structures as release sites in future stocking programs. Methods Forty hatchery-reared yellowfin bream were evenly divided and stocked on either artificial reef or natural habitat within an east-Australian estuary, and tracked using acoustic telemetry. Key results Artificial reefs provided greater habitat complexity than the natural habitat and fish stocked onto these structures showed greater fidelity to their release site and were detected for longer periods of time than those stocked into less complex natural habitat. Conclusions The high residency levels of fish around artificial reef sites indicate they contain resources to support stocked juvenile sparids. Implications Stocked yellowfin bream can tolerate a range of salinity and temperatures, allowing flexibility in stocking programs. Future stocking of bream or other sparids should consider releasing fish onto artificial reefs where available. Additionally, the deployment of reefs could aid existing stocking programs.

Shoreline change model after artificial reefs deployment in Tlangoh, Bangkalan, Madura

Fifteen hexagonal artificial reefs were placed on Tlangoh Beach, Bangkalan, Madura Island, in 2022. The reefs have been planned to reduce shoreline erosion that has been occurring in this location since 2020. Pertamina Hulu Energy – West Madura Offshore (PHE – WMO) will deploy more artificial reefs in their CSR (company social responsibility) program. The effect of the artificial reefs on reducing shoreline erosion was usually observed by the change of morphology and shoreline in the study area. The study of shoreline change has gained significant attention due to its substantial impact on coastal environments. Understanding the dynamics of shoreline alteration is crucial for managing and planning coastal development and preserving coastal ecosystems such as artificial reef deployment. Scientists and researchers have developed a generalized shoreline change model called GENESIS to aid in this understanding. This software provides a valuable tool for predicting and analysing coastal erosion and accretion patterns. This paper discusses the shoreline change model in Tlangoh Beach, Bangkalan Madura, after deploying artificial reefs using GENESIS software. The model shows that the length of the artificial reef layout influences the developed shoreline. The longer the reef placement, the more sediment accumulates in the study area

“Accidental” artificial reefs — lessons from Singapore for coral and seagrass restoration along urban shorelines

Due to rapid urbanization and coastline modification, the city-state of Singapore has lost nearly three-quarters of its intertidal coral reef area and nearly 90% of its subtidal coral reef area since pre-colonial times. However, the recolonization of coral communities has occurred naturally on seawall structures despite the lack of any deliberate planning or intervention. Recent mapping of coastal habitats shows that seawall reefs now form a significant proportion of habitat occupied by hard corals in Singapore, including areas where there were historically no coral reefs, and often exist side-by-side with other regenerated marine habitats such as seagrass meadows. These “accidental” artificial reefs demonstrate that new hard coral and seagrass communities can establish along highly urbanized shorelines, albeit in a novel form, and provide ecosystem services to urban communities. Key lessons can be drawn from these case studies, particularly relating to landscape design of urban shorelines to facilitate ecological coral and seagrass restoration. These include constructing seawalls with optimal slope profiles, providing creviced berms at the lower intertidal of seawalls, co-locating seawalls with artificial intertidal lagoons, and considering coral larvae supply in choosing sites for restoration using seawalls. Most importantly, these case studies illustrate the potential of using seawalls to restore hard coral and seagrass habitat on a landscape-scale, especially in urban environments.

Stable Isotope Analysis of Antipatharian Diets from the Northwestern Gulf of Mexico

Antipatharians, or black corals, form a key component of the benthic fauna found throughout the Gulf of Mexico (GOM). In the northwestern GOM, they are a common member of the communities found on the natural relic coral—algal banks known as the South Texas Banks as well as on artificial reefs. They are known to provide important habitat for many ecologically and economically important species in the area but are relatively understudied. Here we present a study on their trophic ecology using stable isotope analysis of carbon and nitrogen from 2 species, Antipathes atlantica and Stichopathes luetkeni from a mesophotic artificial reef in close proximity to the South Texas Banks. We observed that a large proportion of the 2 coral’s diets was composed of detrital matter, likely driven by the continuous disturbance of the benthos by high velocity benthic currents common to the region that support a persistent nepheloid layer below 30 m. Both species also show a reliance on different members of the planktonic community, with A. atlantica consuming more micro and mesozooplankton compared to S. luetkeni. Comparative analysis between soft tissue and skeletal material also indicates that A. atlantica may change its diet on a seasonal basis, while S. luetkeni appears to rely on detrital matter consistently. This study represents the first assessment of the diets of these organisms and provides valuable insight on the trophic ecology of 2 common antipatharian corals in the GOM on natural and artificial reef ecosystems.

Artificial Reef: Turning Old Ships into National Treasures Cardoso, Cintia CPA

Artificial Reef: Turning Old Ships into National Treasures Cardoso, Cintia CPA

An exploratory study of sponges, sponge-associated, and planktonic prokaryotic communities in an artificial coral reef environment

Abstract In the present study, we assessed the sponge fauna, sponge-associated, and planktonic prokaryotic communities residing in Burgers' Zoo Ocean aquarium, Arnhem, the Netherlands. The Ocean aquarium consisted of separate displays and life support systems, and included fish-only systems in addition to a large, 750,000 L tank containing a living, tropical coral reef ecosystem. Sponges were observed throughout the aquarium system and were identified as belonging to the genera Chalinula, Chondrilla, Chondrosia, Cinachyrella, Stylissa, Suberites and Tethya. There was a highly significant difference in composition between sponge-associated and planktonic prokaryotic communities. The tanks in which the sponges were sampled appeared to have a secondary structural effect on prokaryotic composition with sponges and water from the same tanks sharing several microorganisms. Both sponge-associated and planktonic prokaryotic communities housed prokaryotic taxa, which were highly similar to microorganisms previously recorded in sponges or coral reef environments, including taxa potentially involved in nitrification, denitrification, sulphur oxidation, and antibiotic biosynthesis. Several abundant microorganisms were only recorded in sponges and these may play a role in maintaining water quality in the aquarium system. Potential pathogens, e.g. related to Photobacterium damselae, and beneficial organisms, e.g. related to Pseudovibrio denitrificans, were also detected. The present study showed that Burgers' Zoo Ocean aquarium housed diverse free-living and host-associated prokaryotic communities. Future research should focus on identifying conditions and microbial communities conducive to a healthy aquarium environment.

Sustainable artificial coral reef restoration using nanoclays and composite hydrogel microcapsules

Nanoclays, nanocomposite hydrogel microcapsules, and encapsulated bacteria can be considered as cement replacements for artificial coral reef development.

Characteristics of microplastics in Dusky-tailed cardinalfish (Taeniamia macroptera) from natural reef and Fish Apartment in Pasir Putih Situbondo, East Java, Indonesia

In order to increase fish resources in Pasir Putih Situbondo area, hundreds of artificial reefs in the form of fish apartment (FA) units were laid on the seabottom in the area since 2008. The FA units made from plastic composed by Polypropylene (PP) dan High Density Polyethylene (HDPE) which claimed to be extremely durable for a long time. However, these types of plastic will still undergo weathering and fragmented along time and causes an increase in microplastic pollution in the seawater. The aims of the study are to determine the density as well as characteristics of microplastic in gills and gastrointestinal tract of Dusky-tailed cardinalfish (Taeniamia macroptera) inhabiting the FA. As comparison, fish specimens also collected from natural reef (NR) whereas microplastics in water column collected from both areas. The physical characteristics (colour, shape and size) observed using compound microscope and OptiLab while chemical characteristics analyzed with ATR-FTIR. In the water column, average density of microplastic was 44 particles/l; dominated by size of 0-20 μm in the surface and 20-40 μm at the depth of ±12 m. Results of independent sample t-test (for samples from the gills) and Mann-Whitney test (for samples from gastrointestinal track) show no difference in term of microplastic density from each organ. However, in the fish from FA, the average density was relatively higher, 8340 particles/gr in the gills and 14250 particles/gr in the gastrointestinal tract; compared to 6480 particles/gr in the gills and 11990 particles/gr in the gastrointestinal tract in the specimens from NA. All microplastics particles dominated by black fragment with the size of 0-20 μm and type of the polymer is PP.

Fish assemblages on shipwrecks versus natural reefs in Colombo, Sri Lanka

Shipwrecks provide important habitat for reef fishes, but few studies have addressed how fish assemblages on wrecks compare to natural communities on nearby reefs in terms of species composition, diversity, richness, and density, particularly in the Indian Ocean. To fill this knowledge gap, we conducted standardized diver-operated video transect surveys on three shipwrecks and three nearby natural sandstone reefs in Colombo, Sri Lanka. The shipwrecks provided a habitat that is structurally more complex than the surrounding reefs. A total of 2918 fish from 20 families and 30 genera were recorded, with 749 observed on reef sites and 2169 on the wrecks. A higher mean density of fish was observed on wrecks [mean (SE) = 17.2 (5) fish per 125 m2] than on natural reefs [11.9 (4) per 125 m2]. This difference was predominantly due to the snappers (Lutjanidae), which tended to aggregate in large schools in and around wrecks and constitute a resource for local artisanal fisheries. Wrecks and natural reefs presented similar levels of diversity at the family and genus level and shared 86.7% of genera. They nonetheless showed significant differences in community composition at both the family and genus level. Higher abundances of snappers, cardinalfishes (Apogonidae), and fusiliers (Caesionidae) were recorded on wreck sites while the natural reefs presented higher abundances of damselfishes (Pomacentridae) and barracudas (Sphyraenidae). These results differ from previous similar studies, indicating that differences in fish communities between wrecks and natural reefs can be idiosyncratic. This study highlights the role of shipwrecks as artificial reef structures and their relevance for small-scale fisheries and SCUBA diving tourism.

Marine Ecosystem Restoring by High Complexity Artificial Reefs (HCAR)

Marine Ecosystem Restoring by High Complexity Artificial Reefs (HCAR)

Oceanographic Analysis for Optimal Lobster Artificial Reef Placement in Prigi Bay, East Java

Oceanographic states are closely related to marine biota’s distribution and breeding patterns, especially in the intertidal zone. This study analyses the water quality variability and their relationship in the water of Prigi Bay. Water quality data was collected in situ using a Water Quality Checker. The statistical analyses were performed by applying PAST software version 4.11. The suitable waters with the best tendency value for the placement of lobster artificial reefs are stations 2 (Karang Gongso) and 4 (Damas). It is not only explained by salinity and turbidity but also by the ORP role, which has the solution potential to transfer electrons from oxidants to reductants, thus affecting the chemical processes. The high potential suitability at 2 locations is due to the concentration of a supportive environment with variability in ORP concentrations, having more potential for electron transfer, which significantly affects the attached benthic life as a pioneer for the reef. Salinity stability is safer from the impact of water mixing from the estuary. Parameter concentrations are more stable according to water temperature standards for coralline algae growth and are affected by turbidity and dissolved oxygen. In addition, other research is needed, such as social factors and fishermen’s activities.

Reef Fish Community Structure in Penyusuk Waters, Bangka Regency, Indonesia (Case Study of Artificial Reef in PT. Artha Cipta Langgeng)

Reef fishes are important components of a healthy coral ecosystem. However, when coral reefs are degraded, reef fishes also lose their habitat resulting in a decline in reef fish production and sustainable livelihood for the communities depending on it. In this study, we determined the status of reef fish communities in an artificial reef at PT Artha Cipta Langgeng in the Penyusuk waters of Bangka Regency, Indonesia. Data on reef fish communities were collected using the underwater visual census (UVC) method, including in situ and ex-situ environmental parameters. A total of 2,987 individuals belonging to 12 reef fish species and five families were recorded across three stations. The abundance of reef fish ranges from 45 to 60 ind/m², categorized as highly abundant. Diversity, evenness, and dominance indices were calculated at 1.18-1.49, 0.56-0.65, and 0.26 -0.36, respectively which are categorized as low to moderate. The environmental parameters in the artificial reef are still within the standard limit for a reef ecosystem. The study emphasizes the importance of artificial reefs as an alternative to a degraded coral reef ecosystem in supporting the thriving existence of reef fishes in the Penyusuk waters.

Global synthesis of effects and feedbacks from artificial reefs on socioecological systems in recreational fisheries

AbstractArtificial reefs have been widely deployed with the intention of increasing fish habitat, enhancing recreational fishery opportunities and providing socio‐economic benefits to surrounding communities. Substantial work has been done to understand the ecology of artificial reefs but the efficacy of artificial reefs as a management tool hinges on socioecological feedbacks that are not well understood. Socioecological feedbacks are difficult to discern because they depend on multiple and complex interactions between fish, fishers, managers and habitats. To better understand the net effects of artificial reefs on recreational fisheries, we conducted a literature review to catalogue effects and feedbacks of artificial reefs. Our global synthesis revealed that artificial reefs may result in a net negative effect on fish populations, at least in the short‐term, as catch‐driven effects bolstering socio‐economic objectives occur more often or at greater intensities than positive biological effects. We have highlighted important effects of artificial reefs and feedbacks that need to be accounted for when considering their deployment in fishery management. There may be unintended consequences if biological benefits from habitat‐to‐fish and fish‐to‐fish feedbacks are outweighed by population losses due to greater socio‐economic benefits from fish‐to‐fisher feedbacks. Taken in concert with their semi‐permanent nature and apparent popularity with stakeholders, a view emerges of artificial reefs possibly functioning as a ‘social‐ecological trap’. This work emphasizes the need for robust assessments of the effects of artificial reefs, as well as more formal decision science approaches for implementing of these structures.

Evaluating the particulate organic matter particles distribution characteristics around artificial reefs using computational fluid dynamics

Particulate organic matters (POMs) are small (<1 mm in diameter) and disperse or accumulate along water flow. Their interaction with an artificial reef (AR) is important because it characterises POM accumulation around an AR, where high productivity can be expected. We therefore investigated the spatial distribution characteristics of POMs for three types of ARs (box-type, cylindrical-type, and hemispherical-type), using computational fluid dynamics (CFD). As a result, the distribution patterns of POM particles were clearly distinguished according to the shape of the ARs. The accumulation of POM particles on the analysis plane was highest in the cylindrical-type AR, followed by the box-type and hemispherical-type ARs. Many POM particles were distributed in regions where the turbulence energy was strong. The larger the diameter and density of the POM particles were, the closer they tended to be in regions with strong vorticity. Based on the distribution and behavioural characteristics of the POM particles, e.g., thick region, empty region, transport limit line, main layer, and column, it is possible to determine the placement model for marine fisheries, such as ARs. Therefore, it is possible to create a POM pool that can form the basis of the marine ecosystem by using marine fishing facilities.

A Numerical Simulation Study and Effectiveness Evaluation on the Flow Field Effect of Trapezoidal Artificial Reefs in Different Layouts

The combined release of artificial reefs in different quantities and arrangements leads to different flow field effects. This study designs a small trapezoidal artificial reef. To optimize the quantity and layout of these reefs, trapezoidal reefs in three different layouts were selected for analysis at five different velocity gradients (0.1, 0.5, 1.0, 1.5, and 2.0 m/s). The effects of disposal spacing and layout on the flow field effect of trapezoidal artificial reefs at different flow velocities were simulated using Ansys Fluent. According to the findings: after simulation, flow velocity could indirectly reflect the distribution of upwelling and back eddy, the scale and strength of upwelling increased as flow velocity increased, and the back eddy showed no obvious variation with flow velocity. In transverse combination mode, both the scale and strength of the upwelling and back eddy were maximized when the reef spacing was 1.0 L; in longitudinal combination mode, upwelling and back eddy reached maximum scale and strength when the disposal spacing of the reefs was 1.5 L of a single reef. In 2020, flow mapping and fishery surveys were carried out in the engineering pilot area. The results showed that the number and species of fish populations with 1.5 L spacing in the vertical combination method were significantly higher than those in other forms, and the structure of the fish reef was stable without any flipping or sliding phenomenon. This study can provide a theoretical reference for the design and the actual deployment of artificial reefs to improve the ecological restoration of the water.

First record of Atlantic Sea anemone (Telmatactis panamensis (Verrill, 1869)) on the artificial reefs of the Syrian coast (Eastern Mediterranean)

First record of Atlantic Sea anemone (Telmatactis panamensis (Verrill, 1869)) on the artificial reefs of the Syrian coast (Eastern Mediterranean)

Temporal and spatial variation in the food web structure in artificial reef areas and adjacent habitats in Haizhou Bay

Artificial reef is regarded as an effective tool for restoring habitats and supporting the marine ecosystem. While the energy flow and material exchange in the food web of artificial reef ecosystem still remain vacant and should be further understood. In this study, stable isotopic characteristics (δ13C and δ15N) were used to identify the trophic niches and potential carbon sources of consumers (fish and invertebrates) in artificial reef areas and adjacent habitats in Haizhou Bay (the estuary area (EA), the aquaculture area (AA), the artificial reef area (AR), the natural area (NA) and the comprehensive effect area (CEA)) in spring and autumn. The results showed that the average δ13C for all consumers decreased from − 16.99 ± 2.07‰ to − 21.81 ± 1.66‰, and the average δ15N ranged from 11.37 ± 0.35‰ to 14.69 ± 0.64‰ in all seasons. A SIBER model revealed highly similar trophic niche among habitats in autumn, and lower overlap in spring. The SIMMR model showed that phytoplankton and sedimentary organic matter (SOM) were the major contributors to consumers, and particulate organic matter (POM) accounted for less contribution. In AA and NA phytoplankton and SOM generally contributed fairly equally to most fish, while single SOM sources were major contributors to nearly all the species in AR and CEA. Our findings reveal that ARs can serve as seascape mosaics to increase fish community diversity because of their high variation in the δ13C value and the trophic niches from EA to the NA. Preliminary multidisciplinary studies are needed for the mitigation of effects before any implementations deployed to the offshore waters that influence habitat connectivity, especially some habitat–specific migratory species.

Seasonal dynamics response mechanism of benthic microbial community to artificial reef habitats

Artificial reefs (ARs) have been globally deployed to enhance and restore coastal resource and ecosystems. Microorganisms play an essential role in marine ecosystems, while the knowledge regarding the impact of ARs on microecology is still limited, particularly data concerning the response of benthic microbial community to AR habitats. In this study, the seasonal dynamics of benthic microbial community in AR and adjacent non-artificial reef (NAR) areas surrounding Xiaoshi Island were investigated with high-throughput sequencing technology. The results revealed that the diversity and structure of microbial community between AR and NAR both displayed pronounced seasonal dynamics. There was a greater influence of season factors on microbial communities than that of habitat type. The microbial communities in AR and NAR habitats were characterized by a limited number of abundant taxa (ranging from 5 to 12 ASVs) with high relative abundance (8.35–25.53%) and numerous rare taxa (from 5994 to 12412 ASVs) with low relative abundance (11.91%–24.91%). Proteobacteria, Bacteroidota and Desulfobacterota were the common predominant phyla, with the relative abundances ranging from 50.94% to 76.76%. A total of 52 biomarkers were discovered, with 15, 4, 6, and 27 biomarkers identified in spring, summer, autumn and winter, respectively. Co-occurrence network analysis indicated that AR displayed a more complex interaction pattern and higher susceptibility to external disturbances. Furthermore, the neutral model and βNTI analyses revealed that the assembly of microbial communities in both AR and NAR is significantly influenced by stochastic processes. This study could provide valuable insights into the impact of ARs construction on the benthic ecosystems and would greatly facilitate the development and implementation of the future AR projects.

Ecosystem Characteristics and Trophic Model of the Artificial Reef Ecosystem in the Sea of Oman, Sultanate of Oman

This study aimed to understand the structure and function of the artificial reef ecosystem of the Sea of Oman and its stability and maturity. For this study, the trophic model of the Sea of Oman’s artificial reef ecosystem was described using the Ecopath with Ecosim (EwE) ecosystem modeling software (Version 6.6.7). The essential characteristics of the aquatic system were identified using a total of 38 fish species/functional groups, spread across an area of 140 km2 of artificial reef farm. The mean trophic level of the artificial reef ecosystem of the Sea of Oman was 3.039. Sharks were the keystone species of the studied ecosystem. Heniochus acuminatus and Chaetodon gardneri were the species with the highest niche overlap, whereas Acanthurus sohal and other crustaceans, and Terapon puta and Saurida undosquamis were the species with the lowest niche overlap. It was found that the ratio of total primary production to total respiration of the ecosystem studied was more than one, indicating that the system produces more energy than it uses to respire, and the ecosystem of the Sea of Oman can be regarded as a developing system because of its low degree of stability and maturity. The omnivory index was 0.260, the connectance index was 0.159, the total biomass to total throughput ratio was 0.006, Finn’s cycling index was 5.41, the total primary production to total biomass ratio was 64.895, and the total primary production to total respiration ratio was 4.424. The results indicate that the artificial reef ecosystem in the Sea of Oman can be categorized as immature (in the early developmental stage). Further study is needed to improve the input data and track ecosystem health, as well as exploring other management strategies. Based on the outcomes of the study, it is suggested that environmental management of the reef ecosystem, along with the fish catch data, should be taken into consideration for future research.