Articoli di riviste: "Artificial fish habitats"

1

Mellin, C., and D. Ponton. "Assemblages of reef fish settling on artificial substrates: effect of ambient habitat over two temporal scales." Marine and Freshwater Research 60, no. 12 (2009): 1285. http://dx.doi.org/10.1071/mf08319.

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Artificial habitats provide a unique opportunity to investigate how habitat characteristics structure juvenile fish assemblages after settlement. We quantified the differences between assemblages of juvenile fish on artificial substrates moored in macroalgal beds, seagrass beds or coral patches over two temporal scales that corresponded to a short (48 h) and a longer (>2 weeks) immersion time, respectively. The highest abundances were obtained from artificial habitats moored in seagrass beds, whatever the immersion time was. Total abundances of juveniles increased 3-fold between a short and a long immersion, suggesting a net accumulation of individuals with time. Moreover, significant differences in juvenile fish assemblage structure were observed between habitats and between immersion times. Artificial habitats may reflect species-specific habitat preferences at settlement at a meso-scale; however, caution must be paid to the effects of ambient habitat and post-settlement processes on juvenile fish assemblages observed on artificial habitats.

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McIntyre, Alasdair D. "Artificial habitats for fish." Marine Pollution Bulletin 19, no. 3 (1988): 139–40. http://dx.doi.org/10.1016/0025-326x(88)90713-8.

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Pereira, Pedro Henrique Cipresso, Marcus Vinicius Bezerra dos Santos, Daniel Lino Lippi, Pedro Henrique de Paula Silva, and Breno Barros. "Difference in the trophic structure of fish communities between artificial and natural habitats in a tropical estuary." Marine and Freshwater Research 68, no. 3 (2017): 473. http://dx.doi.org/10.1071/mf15326.

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The present study tested the hypothesis that artificial habitats (pier and bridge) harbour different fish trophic guilds compared with natural habitats (mangrove roots) and that the trophic structure of fish communities on estuarine artificial habitats resembles adjacent coral reefs. High-definition cameras were used to survey the fish community associated with the different structures over a 6-month period. Benthos was also analysed following the point intercept method on the different habitats. In the estuary, fish abundance was up to threefold higher and species richness twofold higher on artificial structures compared with the natural habitat. Mangrove roots were mainly inhabited by juvenile carnivores, whereas the pier and bridge were mostly inhabited by sessile invertebrate feeders and roving herbivores. A less diverse benthic community was found on mangrove roots, mostly composed of mud and algae. In contrast, benthos at the bridge and pier was more diverse and dominated by sponges, octocorals and oysters. In addition, fish trophic structure from an adjacent coral reef area showed more than 60% similarity with the fish community on the artificial structures surveyed. The results of the present study indicate that artificial hard structures support unique fish communities compared with natural estuarine mangrove habitats.

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Budijono, Budijono, Ridwan Manda Putra, Muhammad Fauzi, et al. "Observations of fish species diversity in floating artificial habitats in Koto Panjang reservoirs, Indonesia." BIO Web of Conferences 136 (2024): 03008. http://dx.doi.org/10.1051/bioconf/202413603008.

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Monitoring the diversity of fish species in artificial floating habitats that are continuously tested in the waters of the Koto Panjang Reservoir is important to assess the current availability of fish species resources. This study aims to evaluate the increase in fish species in the different artificial floating habitat structures that were tested. This study was conducted from November 2023 to June 2024 in the Koto Panjang Reservoir on 9 existing floating habitat structures. Each structure has 8 attractors with media (raffia rope, plastic rope, packaging bottles) hung at a depth of 2 m. Each structure is equipped with 4 traps to catch fish every month, then counted and identified according to applicable procedures. The catch in all artificial habitats was 189 fish with a total of 21 species from the previous 16 species. The largest number of fish remained in the raffia rope media at 100% and the lowest in the strapping band at 76,2%. Meanwhile, the types of fish found in the reservoir waters were 32 species from the 44 species that had been recorded from previous research. It was concluded that raffia rope media is a media preferred by fish in artificial floating habitats.

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García-Salines, Laura, and Pablo Sanchez-Jerez. "Comparing the Structure of Fish Assemblage among Natural and Artificial Shallow Rocky Habitats." Oceans 5, no. 2 (2024): 244–56. http://dx.doi.org/10.3390/oceans5020015.

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Artificial coastal structures, such as seawalls, breakwaters, and groins, can exert various impacts on the fish communities in the nearby regions. This study focuses on assessing the ecological effects of coastal infrastructure on marine environments, by comparing, at different seasons, the habitat complexity and heterogeneity, as well as their effects on fish assemblages, between the artificial habitat created with the intention of constructing a marina (Puerto Amor) and the natural habitats surrounding the Cabo de la Huerta area in Alicante (Spain). Employing an asymmetric design and examining two temporal and spatial scales, we utilized visual censuses in snorkeling to gauge the abundance and size of fish species, alongside various parameters related to habitat complexity and heterogeneity. The overarching hypothesis is that fish populations associated with artificial habitats will differ in terms of abundance, biomass, species richness, and diversity compared to fish populations associated with natural habitats, due to changes in complexity and heterogeneity. The findings indicate a shift in fish assemblages; for example, the family Labridae showed differences between the two habitat types for several species. These changes were due to the influences of the Posidonia oceanica meadow and algae like Jania rubens; being influenced by biological variables such as Ellisolandia elongata, Oculina patagonica, and Sarcotragus spinosulus; as well as physical variables such as stones, gravel, and blocks. While there is evidence of alteration in fish assemblages due to changes in habitat structure, there is also an increase in richness (9 species/m2) and total abundance and biomass (1000 ind./m2 and 1700 g/m2, respectively) in the artificial habitat. Multivariate analyses reveal that the fish community in Puerto Amor is less homogeneous than the one in the natural habitat. However, these analyses also indicate an overlap between the communities of both habitats, suggesting substantial similarity despite the noted differences. Consequently, although the habitat alteration has impacted fish populations, it has not diminished abundance, biomass, or species richness. In conclusion, the artificial rocky habitat resulting from the construction attempt at Puerto Amor harbor has fish populations with ecological significance and its removal could lead to undesirable impacts in the area, as the fish assemblages have become well established.

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Flávio, Hugo, Rochelle Seitz, David Eggleston, Jon C. Svendsen, and Josianne Støttrup. "Hard-bottom habitats support commercially important fish species: a systematic review for the North Atlantic Ocean and Baltic Sea." PeerJ 11 (January 17, 2023): e14681. http://dx.doi.org/10.7717/peerj.14681.

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Hard-bottom habitats span a range of natural substrates (e.g., boulders, cobble) and artificial habitats (e.g., the base of wind turbines, oil platforms). These hard-bottom habitats can provide a variety of ecosystem services, ranging from the enhancement of fish biomass and production to providing erosion control. Management decisions regarding the construction or fate of hard-bottom habitats require information on the ecological functions of these habitats, particularly for species targeted in ecosystem-based fisheries management. This study provides a systematic review of the relationships of various hard-bottom habitats to individual commercially harvested species that are managed jointly across the Atlantic by the International Council for the Exploration of the Sea (ICES). We systemically reviewed peer-reviewed publications on hard-bottom habitats including both natural and artificial reefs, after applying various exclusion criteria. Most studies were conducted on near-shore hard-bottom habitats, and habitat importance varied according to fish species and region. We quantified the frequency with which studies demonstrate that natural and artificial hard-bottom habitats function as spawning grounds, settlement and nursery areas, and foraging grounds, as well as provide stepping-stones during migration, or new home ranges. Hard-bottom habitats generally support higher fish densities than surrounding habitat types, although not all fish species benefit from hard-bottom habitats. Of the commercially important species, cod (Gadus morhua) was the most frequently studied species, with enhanced biomass, density, feeding, and spawning on hard-bottom habitats compared to unstructured habitats. Moreover, hard-bottom habitats appear to be of particular importance for spawning of herring (Clupea harengus). Collectively, data indicate that loss of hard-bottom habitats may translate into less-favourable conditions for spawning and biomass of diverse commercial species, including cod and herring.

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Paxton, Avery B., and Derek Smith. "Visual cues from an underwater illusion increase relative abundance of highly reef-associated fish on an artificial reef." Marine and Freshwater Research 69, no. 4 (2018): 614. http://dx.doi.org/10.1071/mf17179.

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Cues from visual, auditory and olfactory stimuli affect habitat selection by reef fish, yet questions remain regarding how fish use visual cues to select habitats. With growing numbers of human-made structures, such as artificial reefs, deployed on ocean floors, understanding how visual cues influence fish selection of human-made habitats is timely. We conducted a field experiment to test whether visual stimuli influenced the relative abundance of fish on an artificial reef. We discovered that visual cues from an illusion created by a mirror installed on the reef increased the relative abundance of highly reef-associated fish. Specifically, when exposed to the mirror, numbers of highly reef-associated fish increased 35% relative to an experimental control treatment with a transparent added structure and 54% relative to a full control without an added structure. These results demonstrate that visual cues, such as illusions of additional habitat and more fish, can entice more highly reef-associated fish to use artificial reefs and play a more substantial role in habitat selection than the effects of added physical structures alone. As numbers of human-made marine structures continue to increase, simple augmentations enhancing visual evidence of available habitat structure or relative fish abundance may serve to increase the local abundance of fish.

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8

Langhamer, Olivia. "Artificial Reef Effect in relation to Offshore Renewable Energy Conversion: State of the Art." Scientific World Journal 2012 (2012): 1–8. http://dx.doi.org/10.1100/2012/386713.

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The rapid worldwide growth of offshore renewable energy production will provide marine organisms with new hard substrate for colonization, thus acting as artificial reefs. The artificial reef effect is important when constructing, for example, scour protections since it can generate an enhanced habitat. Specifically, artificial structures can create increased heterogeneity in the area important for species diversity and density. Offshore energy installations also have the positive side effect as they are a sanctuary area for trawled organisms. Higher survival of fish and bigger fish is an expected outcome that can contribute to a spillover to outer areas. One negative side effect is that invasive species can find new habitats in artificial reefs and thus influence the native habitats and their associated environment negatively. Different scour protections in offshore wind farms can create new habitats compensating for habitat loss by offshore energy installations. These created habitats differ from the lost habitat in species composition substantially. A positive reef effect is dependent on the nature and the location of the reef and the characteristics of the native populations. An increase in surface area of scour protections by using specially designed material can also support the reef effect and its productivity.

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9

Bi, Sheng, Han Lai, Dingli Guo, et al. "The Characteristics of Intestinal Bacterial Community in Three Omnivorous Fishes and Their Interaction with Microbiota from Habitats." Microorganisms 9, no. 10 (2021): 2125. http://dx.doi.org/10.3390/microorganisms9102125.

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Artificial fishery habitats have been extensively used for fishery resource protection and water habitat restoration, and they could attract a large number of omnivorous fishes to gather together. This study intended to reveal the relationship between bacterial communities in the habitats (water and sediment) and intestines of omnivorous fishes (Oreochromis mossambicus, Toxabramis houdemeri and Hemiculter leucisculus). Therefore, we investigated the bacterial communities of samples collected from intestines, water, and sediments in artificial fishery habitats via 16S rRNA metabarcoding high-throughput sequencing technology. The results showed that there were significant differences in the composition, core indicators, diversity and prediction functions in water, sediments, and intestinal microbial communities of the three omnivorous fish. The microbial diversities were significantly higher in habitats than in intestines. The analysis of similarity (ANOSIM) and nonmetric multidimensional scaling (NMDS) results indicated that the intestine microbial communities (T. houdemeri and H. leucisculus) were more similar to the water microbiota, but the intestine microbial communities (O. mossambicus) were more similar to the sediments. Source tracking analysis also confirmed that the contribution of habitat characteristics to omnivorous fish intestinal microorganisms was different; the sediment had a greater contribution than water to the intestinal microbiota of O. mossambicus, which was consistent with their benthic habit. Moreover, the functional prediction results showed that there were unique core indicators and functions between the bacterial community of habitats and intestines. Altogether, these results can enhance our understanding of the bacterial composition and functions about omnivorous fish intestines and their living with habitats, which have provided new information for the ecological benefits of artificial fishery habitats from the perspective of bacterial ecology and contributed to apply artificial fishery habitats in more rivers.

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Radford, C. A., C. J. Sim-Smith, and A. G. Jeffs. "Can larval snapper, Pagrus auratus, smell their new home?" Marine and Freshwater Research 63, no. 10 (2012): 898. http://dx.doi.org/10.1071/mf12118.

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The ability to find a suitable settlement habitat after a pelagic larval period represents a significant challenge to marine settlement-stage larvae, and the mechanisms by which they achieve this are poorly understood. There is good evidence that olfactory cues are used by some coral reef fish larvae to locate suitable settlement habitats; however, the same understanding is lacking for marine temperate fish. Here we show for the first time that the larvae of an important commercial and recreational marine temperate fish, Pagrus auratus, can use olfactory cues to orient to appropriate settlement habitat. Using pairwise choice experiments, naive hatchery reared fish were offered water collected from a range of habitats in the Kaipara Harbour, an important nursery area for P. auratus. Larvae selected to swim towards water taken from over seagrass beds, their preferred settlement habitat, than water taken from the harbour entrance, Asian date mussel habitat, artificial seawater or artificial seawater in which seagrass had been soaked. The preference by the fish for water from the seagrass habitat over artificial seawater in which seagrass had been soaked strongly suggests that chemical cues from sources other than seagrass, such as from prey or conspecifics present in the seagrass habitat, may also be involved.

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Yılmaz, Özgür, Sinan Mavruk, and Gökhan Gökçe. "Artificial seagrass experiments in the Northeast Mediterranean." Ege Journal of Fisheries and Aquatic Sciences 38, no. 3 (2021): 355–64. http://dx.doi.org/10.12714/egejfas.38.3.12.

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: Seagrasses provide important nursery grounds, shelter and natural habitats for juvenile fish. In this study, we evaluated if artificially created seagrass areas can play the same role as the natural seagrass (NS) habitats. The study was carried out in three different stations on the coast of Yumurtalık, Adana, selected according to the seagrass areas. Artificial seagrass (AS) was made of polypropylene ribbon and fixed on the ground in the designated areas with a depth of 0.5 m on average. Sampling was carried out with a beach seine net once a week at stations between 28 April 2016 and 11 August 2016. Sampled fish were identified to the lowest possible taxonomic level. Based on our results, the fish abundance and species richness of NS and AS habitats were not statistically different, whereas the both parameters were significantly lower in sandy (S) habitats (p<0.001). Moreover, the species composition of NS and AS habitats was found to be similar each other, whereas the composition was significantly different in S habitats. This study, conducted in the Northeast Mediterranean, shows that AS habitats effect the distribution of juvenile fish.

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Budijono, Budijono, Eko Prianto, Muhammad Fauzi, et al. "First report of artificial floating habitat to increase the fish population in Koto Panjang reservoir, Indonesia." BIO Web of Conferences 74 (2023): 04002. http://dx.doi.org/10.1051/bioconf/20237404002.

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The artificial habitat being tested in the Koto Panjang Reservoir is a step to anticipate the emergence of symptoms of a decline in fisheries resources at this time. This study aims to examine the types of artificial media in the artificial habitat structure favored by fish. This research was carried out from June 2022 to August 2023 in the Koto Panjang Reservoir. Artificial habitat is created as many as 10 structures. Each structure has 8 attractors with different media (raffia rope, plastic bonded rope, palm fiber, packing bottles, and coconut leaves, which are suspended at a depth of 2-8 meters. Four units of fish traps are placed on each structure for monthly fish collection, then counted and identified according to applicable procedures. The result shown that were 232 fish caught in all artificial habitats consisting of 16 species, excluding 1 type of freshwater shrimp. On raffia cord media, more types of fish were caught, reaching 56% compared to 12% on packaging plastic bottle media. It was concluded that this artificial floating habitat with different media could be a gathering and foraging place represented by 16 fish species from the 44 fish species recorded in this reservoir.

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Sreekanth, G. B., N. Manju Lekshmi, and Ajey Patil. "Fish Assemblages on Artificial Fish Habitats in Estuaries: A Comparison with Natural Rocky Habitats." National Academy Science Letters 43, no. 2 (2019): 125–31. http://dx.doi.org/10.1007/s40009-019-00825-x.

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Zhou, Lei, Dingli Guo, Lei Zeng, et al. "The structuring role of artificial structure on fish assemblages in a dammed river of the Pearl River in China." Aquatic Living Resources 31 (2018): 15. http://dx.doi.org/10.1051/alr/2018003.

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To address the fish use patterns of artificial structures mimicking floating macrophytes deployed in a impounded tributary of the Pearl River, China, field experiments were performed from December 2014 to June 2016 using multi-mesh gillnet. The fish assemblages using artificial structures differ in terms of species richness, abundance, body size, diversity indices, and ecological traits from fish assemblages on natural barren habitats of this river. Overall, fish abundance, species richness, Shannon diversity index, and functional richness were higher at the artificial structures than at the control sites, while fish length and functional evenness was greater at the control sites in comparison to artificial structures. The introduction of artificial structures did not result in statistically significant effects on fish biomass as artificial structures attracted more individuals with smaller size. Seasonal changes of chlorophyll-a and transparency may affect the efficiency of artificial structure in harboring fishes. This study revealed that artificial structures, as synthesized habitats, are effective in acting as a “fish attractor” and an alternative tool to provide new habitats for smaller individuals in a dammed river like the Youjiang River which is a structure-less ecosystem.

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Tatár, Sándor, Bálint Bajomi, András Specziár, et al. "Habitat establishment, captive breeding and conservation translocation to save threatened populations of the Vulnerable European mudminnow Umbra krameri." Oryx 51, no. 4 (2016): 718–29. http://dx.doi.org/10.1017/s0030605316000533.

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AbstractIn Europe 37% of freshwater fish are threatened. However, conservation activity is less widespread for fish compared to other vertebrate groups. The Vulnerable European mudminnow Umbra krameri is a marshland fish endemic to the Carpathian Basin. Its range and population have declined significantly since the 1990s. The main threats to the species are habitat loss and the invasive Chinese sleeper Perccottus glenii. During 2008–2012 a species conservation programme was established to rescue broodstocks from threatened populations, breed them under controlled conditions, translocate both rescued fish and their laboratory-reared offspring to surrogate habitats, and finally reintroduce offspring to their original habitats. Broodstocks from three threatened habitats were bred in the laboratory and produced offspring appropriate for stocking. Six artificial ponds were created in the pilot study area according to the environmental needs of the species, four of which proved to be suitable surrogate habitats in which translocated fish survived and reproduced successfully. Populations in the original habitats were supplemented with fish from laboratory breeding and from the natural recruitment of surrogate habitats, with special care of the corresponding broodstocks. Future challenges include improving our knowledge about the ecological processes in which the European mudminnow participates, identifying the most threatened populations, habitats suitable for restoration and potential areas for creation of surrogate habitats, and enhancing induced propagation methodology.

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Henderson, Christopher J., Ben L. Gilby, Thomas A. Schlacher, et al. "Contrasting effects of mangroves and armoured shorelines on fish assemblages in tropical estuarine seascapes." ICES Journal of Marine Science 76, no. 4 (2019): 1052–61. http://dx.doi.org/10.1093/icesjms/fsz007.

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Abstract Coastal seascapes are composed of a diversity of habitats that are linked in space and time by the movement of organisms. The context and configuration of coastal ecosystems shapes many important properties of animal assemblages, but potential seascape effects of natural and artificial habitats on nearby habitats are typically considered in isolation. We test whether, and how, the seascape context of natural and urban habitats modified fish assemblages across estuaries. Fish were sampled with underwater videos in five habitat types (mangroves, rock bars, log snags, unvegetated sediments, armoured shorelines) in 17 estuaries in eastern Australia. Different habitats supported distinct fish assemblages, but the spatial context of mangroves and armoured shorelines had pervasive ecological effects that extended across entire estuaries. In most estuarine habitats, fish diversity and abundance was greatest when they were in close proximity of mangroves, and decreased due to the proximity of armoured shorelines. Many cities are centred on estuaries, and urban expansion is often associated with the fragmentation of mangrove forests. Our findings emphasize that these transformations of urban estuarine landscapes are likely to propagate to broader ecological impacts detectable in multiple habitats beyond mangrove forests.

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Baker, Ronald, Dakota Bilbrey, Aaron Bland, et al. "Underwater Video as a Tool to Quantify Fish Density in Complex Coastal Habitats." Diversity 14, no. 1 (2022): 50. http://dx.doi.org/10.3390/d14010050.

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Habitat loss is a serious issue threatening biodiversity across the planet, including coastal habitats that support important fish populations. Many coastal areas have been extensively modified by the construction of infrastructure such as ports, seawalls, docks, and armored shorelines. In addition, habitat restoration and enhancement projects often include constructed breakwaters or reefs. Such infrastructure may have incidental or intended habitat values for fish, yet their physical complexity makes quantitatively sampling these habitats with traditional gears challenging. We used a fleet of unbaited underwater video cameras to quantify fish communities across a variety of constructed and natural habitats in Perdido and Pensacola Bays in the central northern Gulf of Mexico. Between 2019 and 2021, we collected almost 350 replicate 10 min point census videos from rock jetty, seawall, commercial, public, and private docks, artificial reef, restored oyster reef, seagrass, and shallow sandy habitats. We extracted standard metrics of Frequency of Occurrence and MaxN, as well as more recently developed MeanCount for each taxon observed. Using a simple method to measure the visibility range at each sampling site, we calculated the area of the field of view to convert MeanCount to density estimates. Our data revealed abundant fish assemblages on constructed habitats, dominated by important fisheries species, including grey snapper Lutjanus griseus and sheepshead Archosargus probatocephalus. Our analyses suggest that density estimates may be obtained for larger fisheries species under suitable conditions. Although video is limited in more turbid estuarine areas, where conditions allow, it offers a tool to quantify fish communities in structurally complex habitats inaccessible to other quantitative gears.

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Magellan, Kit, Olaf Weyl, and Anthony Booth. "Preference for Artificial Refugia over Natural Refugia in an Endangered Fish." Diversity 13, no. 12 (2021): 635. http://dx.doi.org/10.3390/d13120635.

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The availability of appropriate refugia may ameliorate some impacts of habitat degradation and can aid in the conservation of target species. In addition to natural refugia, the provision of artificial refugia may be viable, particularly in degraded habitats. We examined the conservation potential of natural and artificial refugia for the endangered Eastern Cape redfin, Pseudobarbus afer. We show that deeper water is preferred so is likely to constitute a natural refuge. However, this preference is overridden by the provision of artificial refugia (a plastic pipe). We highlight that the most important habitat factor in the conservation of P. afer is availability of suitable natural refugia through avoidance of habitat destruction. However, when redfin habitat is already compromised, appropriate artificial refugia may supplement the protection provided by natural refugia and may provide benefits to the whole aquatic community.

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Le, Dung Quang, Siau Yin Fui, Rumeaida Mat Piah, et al. "Isotopic evidence of connectivity between an inshore vegetated lagoon (nursery habitat) and coastal artificial reefs (adult habitats) for the reef fish Lethrinus lentjan on the Terengganu coast, Malaysia." Marine and Freshwater Research 70, no. 12 (2019): 1675. http://dx.doi.org/10.1071/mf18302.

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Stable isotope analyses of muscle tissue (δ13Cmuscle and δ15Nmuscle) and otoliths (δ13Cotolith and δ18Ootolith) were used to retrospectively track habitat uses of Lethrinus lentjan, and to determine any association between Setiu Lagoon (nursery habitat) and coastal artificial reefs (CARs; adult habitats) on the Terengganu coast, Malaysia. Muscle stable isotopes exhibited a spatial change from inshore to offshore habitats associated with growth, possibly related to the reef-ward movement of the fish. Otolith stable isotopes of adult fish from CARs were measured in juvenile (from outside the core to the first opaque zone of otolith) and adult (the edge of otolith) portions and were compared with those of juveniles from Setiu Lagoon, suggesting that the adult fish may not primarily use the lagoon as a nursery before ontogenetically migrating to CARs. The effects of coastal currents between monsoonal seasons could reorientate offshore juvenile migration; hence, adult cohorts in CARs may be replenished from various nursery habitats along the coast. Additionally, similarities in the δ18Ootolith values of juvenile and adult sections suggested that some individuals may not spend their juvenile phases in shallow estuarine habitats. Based on the findings of this study, we recommend that coastal conservation strategies take into account multiple nursery habitats rather than a single one.

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Nagayama, Shigeya, Yôichi Kawaguchi, Daisuke Nakano, and Futoshi Nakamura. "Summer microhabitat partitioning by different size classes of masu salmon (Oncorhynchus masou) in habitats formed by installed large wood in a large lowland river." Canadian Journal of Fisheries and Aquatic Sciences 66, no. 1 (2009): 42–51. http://dx.doi.org/10.1139/f08-191.

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Different size classes of masu salmon ( Oncorhynchus masou ) were partitioned in three-dimensional space in habitats created by artificially installed large wood (LW) structures in a large river. Fish >300 mm in size (L-sized) returning from the ocean distinctly occurred in sheltered areas near the riverbed, which had a moderate current velocity and contained large root wads or tree trunks; 140–200 mm (M-sized) and 100–120 mm (S-sized) fish selected deep areas of high velocity current adjacent to LW structures; ≤80 mm fish (SS-sized) were most common in the lower depth layers throughout all LW habitats, including shallow areas with moderate currents where LW structures blocked the fast currents. Some SS-sized fish used cover areas provided by branches and leaves. Masu salmon abundance in all size classes combined was greater in habitats with LW structures than in habitats without them. Our study suggests that the natural recruitment of whole trees from the riparian zone or artificial placement of whole trees will have a profound effect on creating salmonid habitats in large rivers.

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Bosch, Néstor E., Jorge M. S. Gonçalves, Fernando Tuya, and Karim Erzini. "Marinas as habitats for nearshore fish assemblages: comparative analysis of underwater visual census, baited cameras and fish traps." Scientia Marina 81, no. 2 (2017): 159. http://dx.doi.org/10.3989/scimar.04540.20a.

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Understanding the ecological role that artificial structures might play on nearshore fish assemblages requires the collection of accurate and reliable data through efficient sampling techniques. In this work, differences in the composition and structure of fish assemblages between the inner and outer sides of three marinas located in the temperate northern-eastern Atlantic Ocean were tested using three complementary sampling techniques: underwater visual censuses (UVC), baited cameras (BCs) and fish traps (FTs). UVCs and BCs recorded a comparable number and relative abundance of species, which in turn were much greater than those recorded by FTs. This finding supports the use of UVCs and BCs over FTs for broad ecologically studies, especially when dealing with structurally complex habitats such as artificial structures. We found differences in fish assemblage structure between the inner and outer sides of marinas, independently of the sampling method. Four small-sized species (Similiparma lurida, Thalassoma pavo, Sarpa salpa and Symphodus roissali) associated with structurally complex vegetated habitats dominated, in terms of abundance, the outer sides of marinas; Diplodus vulgaris, Diplodus sargus and Gobius niger, species with high ecological plasticity in habitat requirements, dominated the inner sides of marinas. The information provided in this study is of great interest for developing sound monitoring programmes to ascertain the effects of artificial structures on fish communities.

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Onyiaji MU, Nwachukwu MO, and Nmezi SN. "The parasite prevalence in Clarias gariepinus from artificial and natural habitats in Oguta imo state Nigeria." World Journal of Advanced Research and Reviews 23, no. 2 (2024): 1998–2007. http://dx.doi.org/10.30574/wjarr.2024.23.2.2423.

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This study revealed the presence of parasites in the two habitats under study. The endoparasites recovered were found to belong to Cammallanida, Pseudophyllida, and Plagiorchiida taxonomic group. Both habitats were noted to be sparingly infected; however, the natural habitat was more infected than the cultured habitat. The physicochemical parameters assayed in this study of the water and sediment samples from all the locations indicate that the water samples fall within the stipulated range of acceptability by the World Health Organization (WHO). The heavy metal concentrations in fish tissues were also within WHO set limits for the survival of aquatic organisms. However, prolonged consumption of the fish species will have adverse effects since heavy metals can bioaccumulate overtime. By implication, from the current result it may be confirmed that catfish obtained from fish pond is healthier than the uninhabited fish type in relationships of nutrient substances for human feeding. This could be due to the fact different habitat of different species the body pattern varies nutritionally. Findings from this work showed that constant monitoring of water parameters provide insight to the health of fish and aquatic ecosystems as whole. Finally, it can be inferred from the results of this study that for consumers purchasing the products in large quantities on a regularly basis, a public health hazard will definitely exist especially from natural catfish where pollution is more pronounced as a result of human activities. On the other side, no hazard might exist through the consumption of average amount of such fishes since it is within WHO permissible limits.

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Noonan, Kara, Thomas Fair, Kristiaan Matthee, Kelsey Sox, Kylie Smith, and Michael Childress. "Reef Fish Associations with Natural and Artificial Structures in the Florida Keys." Oceans 2, no. 3 (2021): 634–47. http://dx.doi.org/10.3390/oceans2030036.

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Throughout the Caribbean, coral reefs are transitioning from rugose, coral-dominated communities to flat, soft coral-dominated habitats, triggering declines in biodiversity. To help mitigate these losses, artificial structures have been used to re-create substrate complexity and support reef inhabitants. This study used natural and artificial structures to investigate the factors influencing the use of habitat by reef fish. During 2018 and 2019, divers added artificial structures and monitored the fish assemblages associating with both the artificial structures and naturally occurring corals. Overall, there were more fish on natural structures than on artificial structures. While structure shape did not influence fish use, there was a non-significant trend for increased use of larger structures. Fish observations did not differ across a gradient of shallow, complex reefs to deeper, flatter reefs; however, analyses of feeding guilds revealed clearer patterns: herbivores and omnivores were positively associated with low rugosity reefs where macroalgal abundance was higher, whereas invertivores preferred more rugose reefs. These results suggest that as reefs lose structural complexity, fish communities may become dominated by herbivores and omnivores. It also appears that the addition of artificial structures of the type used here may not mitigate the effects of structure loss on reef fish assemblages.

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24

J. Giglio, Vinicius, Johnatas Adelir-Alves, Leopoldo C. Gerhardinger, Fabiano C. Grecco, Felippe A. Daros, and Áthila A. Bertoncini. "Habitat use and abundance of goliath grouper Epinephelus itajara in Brazil: a participative survey." Neotropical Ichthyology 12, no. 4 (2014): 803–10. http://dx.doi.org/10.1590/1982-0224-20130166.

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Developing survey strategies for threatened species is often limited by access to sufficient individuals to acquire information needed to design appropriate conservation measures. The goliath grouper (Epinephelus itajara) is a large reef fish, globally classified as critically endangered. In Brazil, fishing has been prohibited since 2002. Herein we investigated habitat use and abundance of E. itajara in Brazil drawn from a participative survey, which engaged volunteer divers in data-collection. A total of 188 reports were recorded between 2005 to 2011 throughout 13 Brazilian states. Our results revealed that habitat type influenced the relationship between total length and depth of occurrence of E. itajara. We observed a significant difference between habitats, artificial presented a nonlinear and natural an asymptotic relationship. This study underscores the importance of developing conservation measures addressing specific habitats and locations to enhance population recovery. Artificial structures (shipwrecks and manmade reefs) are critical habitats that must be considered as highly sensitive areas to E. itajara strategic conservation policies. We suggest the creation and implementation of marine protected areas, as key strategies for E. itajaraconservation, especially for artificial habitats and aggregation sites.

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25

Stuart-Smith, R. D., J. F. Stuart-Smith, R. W. G. White, and L. A. Barmuta. "The effects of turbidity and complex habitats on the feeding of a galaxiid fish are clear and simple." Marine and Freshwater Research 58, no. 5 (2007): 429. http://dx.doi.org/10.1071/mf06240.

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The habitat used by animals plays an important role in their interactions with predators and prey. By using complex habitats such as areas of dense macrophyte cover in response to elevated predation risk, small fishes may reduce their foraging success. Because the threat of predation by introduced brown trout increases the use of complex habitats by the threatened Galaxias auratus (Johnston), we experimentally examined its foraging in different habitats to estimate indirect impacts of brown trout presence. The lakes in which G. auratus lives have recently become more turbid, so the experiment was also conducted under different turbidity levels. Laboratory feeding trials in which planktonic and epibenthic prey were simultaneously offered to G. auratus in the presence or absence of artificial macrophytes and at three turbidity levels (0, 50 and 100 NTU) revealed that its overall foraging success was unaffected by habitat complexity; however, in trials with artificial macrophytes, G. auratus consumed a greater proportion of planktonic prey than in the absence of artificial macrophytes. Neither overall foraging success nor prey selection by G. auratus was affected by high turbidity, indicating that water clarity does not appear to directly negatively impact its feeding. The switch in prey types would probably not be detrimental to G. auratus in the long term, and thus it appears that there is no substantial feeding cost associated with its increased use of complex habitats. It could, however, affect lower trophic levels in the lakes to which it is endemic.

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26

Hunter, W. R., and M. D. J. Sayer. "The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs." ICES Journal of Marine Science 66, no. 4 (2009): 691–98. http://dx.doi.org/10.1093/icesjms/fsp058.

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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.

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27

Simonsen, Kirsten A., James H. Cowan Jr, and Andrew J. Fischer. "Examination of an Estuarine Fish Assemblage Over an Inshore Artificial Reef." Open Fish Science Journal 6, no. 1 (2013): 48–57. http://dx.doi.org/10.2174/1874401x01306010048.

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The perceived value of oyster reefs as fish habitat has led to many restoration projects in areas of historically high oyster populations. This study evaluated fish usage of a limestone cobble mimic oyster reef in Barataria Bay, Louisiana, as compared to a mud-bottom reference site. Emphasis was given to species of economic and ecological importance, including spotted seatrout (Cynoscion nebulosus), Atlantic croaker (Micropogonias undulatus), and bay anchovy (Anchoa mitchilli). There were no observed differences in community structure or catch per unit effort (CPUE) between habitats, likely due to high variability in the data, though seasonal differences were observed. CPUE of spotted seatrout, Atlantic croaker, and bay anchovy did not differ between habitats. Seasonal differences in abundance were detected, with significantly higher CPUE of spotted seatrout in summer, of Atlantic croaker in spring and summer, and of bay anchovy in winter. Spotted seatrout and Atlantic croaker were both significantly larger over the artificial reef, while bay anchovy were significantly larger over the mud bottom. Spotted seatrout, a prized recreational fishing species in Louisiana, appeared to be the only species that showed higher biomass, determined by numbers and size, at the the artificial reef. This is important in the context of managing habitat enhancement projects. While the reef did not increase numbers or species richness of the overall fish community, it did have an effect on one recreationally important species. Therefore, the success of such projects is based as much on the intended purpose, as its affect on the overall community.

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28

Munasik, Munasik, Aldion Adin Nugroho, Retno Hartati, Agus Sabdono, Sugiyanto Sugiyanto, and Denny Nugroho Sugianto. "Struktur Komunitas Ikan Karang dan Tutupan Karang pada Terumbu Buatan Artificial Patch Reef (APR)." Jurnal Kelautan Tropis 23, no. 3 (2020): 333–40. http://dx.doi.org/10.14710/jkt.v23i3.9171.

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Artificial Patch Reef (APR) have been applied as a new method for Biodiversity Conservation Program at Panjang Island, Jepara since 2015. Previous study suggested that design and location of artificial reefs installation affected to abundance of reef fishes, associated with the artificial reef. This study aims to investigated community structure of reef fishes associated to artificial patch reef comparing to reef fishes in nearby natural reefs. Assessment of coral reef condition on two habitats were conducted on July 2019, after 4 years deployment. The results show that artificial patch reefs with a percentage of live coral cover are less than half of natural coral reefs, and have succeeded in increasing the abundance of reef fish with nearly the same density and community structure resembling reef fish in natural coral reefs. The similarity in community structure of the two habitats is probably due to the similarity in habitat type and morphology of the hard corals. The results indicate that Artificial Patch Reef (APR) reefs have increased the coral cover of Acropora branching and resulted in increased reef fish abundance which is compatible with reef fish communities associated with natural coral reefs around it. Aplikasi metode baru terumbu buatan Artificial patch Reef (APR) pada Program Konservasi Bioiversitas Pulau Panjang, Jepara telah dilakukan sejak 2015. Hasil studi menunjukkan bahwa pemilihan desain dan lokasi pemasangan terumbu buatan yang tepat akan meningkatkan kelimpahan ikan karang. Tujuan penelitian ini adalah untuk mengetahui keberhasilan penerapan terumbu buatan APR melalui kelimpahan ikan karang yang berasosiasi pada terumbu buatan dan terumbu karang alami di sekitarnya. Penilaian kondisi terumbu karang tersebut telah dilakukan pada Juli 2019 setelah 4 (empat) tahun pemasangan terumbu buatan. Hasil studi menunjukkan bahwa terumbu buatan dengan persentase tutupan karang hidup lebih kecil, separuhnya dari tutupan pada terumbu karang alami telah berhasil meningkatkan kelimpahan ikan karang dengan densitas hampir sama dan struktur komunitasnya menyerupai ikan karang yang berasosiasi dengan terumbu karang alami. Kesamaan struktur komunitas kedua habitat kemungkinan akibat kesamaan tipe habitat dan morfologi karang keras penyusunya. Hasil ini mengindikasikan bahwa terumbu buatan Artificial patch Reef (APR) telah meningkatkan tutupan karang bercabang Acropora dan berakibat terhadap meningkatnya kelimpahan ikan karang yang sesuai dengan komunitas ikan karang yang berasosiasi dengan terumbu karang alami di sekitarnya.

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29

Boakes, Zach, Alice E. Hall, Georgia CA Jones, Rahmadi Prasetijo, Richard Stafford, and Yunaldi Yahya. "Artificial coral reefs as a localised approach to increase fish biodiversity and abundance along the North Bali coastline." AIMS Geosciences 8, no. 2 (2022): 303–25. http://dx.doi.org/10.3934/geosci.2022018.

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<abstract> <p>Coral reefs face worldwide decline from threats such as climate change, destructive fishing practices, overfishing and pollution. Artificial reefs have shown potential as a method to mitigate localised habitat loss and biodiversity decline on degraded coral reefs. The health of coral reefs in Indonesia and their associated faunal populations have displayed a downward trend in recent decades, and community-managed non-government organisations have started using artificial reefs to restore local degraded reef habitats. In this study, we demonstrate how locally-managed NGOs and communities in north Bali, Indonesia have implemented artificial reef projects, and assess the associated benefits to biodiversity. Using Remote Underwater Video (RUV) over a 3 month period in north Bali, fish assemblages on two artificial reefs of different ages (new and mature) were compared to two nearby natural habitats: degraded sand flats and relatively healthy coral reefs. When compared with a nearby degraded sand habitat, both artificial reefs displayed a significantly higher number of species, which for the mature artificial reef was not statistically different to a nearby coral reef. Community structure was also compared, again showing similarity between artificial reefs and natural coral reefs, but differing in a few species, including specific damselfish and wrasse. This study is one of few which highlight the potential of artificial reef habitat enhancement in Indonesia, and suggests that these structures can provide ecologically equivalent mobile faunal communities to a natural reef on a localised scale. As such, well designed projects may be able to provide some local ecosystem services lost from degraded coral reefs, and become an important focus for coastal communities.</p> </abstract>

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30

Keller, Krystle, James A. Smith, Michael B. Lowry, Matthew D. Taylor, and Iain M. Suthers. "Multispecies presence and connectivity around a designed artificial reef." Marine and Freshwater Research 68, no. 8 (2017): 1489. http://dx.doi.org/10.1071/mf16127.

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A goal of designed artificial reefs (ARs) is to enhance fish abundance, species diversity and fishing opportunities by providing food and refuge for fish. Quantifying the contribution of ARs to coastal ecosystems and fisheries productivity requires an understanding of fish presence at the structure and connectivity with surrounding habitats. In the present study, the movements and presence of 10 eastern fiddler rays (Trygonorrhina fasciata), 17 Port Jackson sharks (Heterodontus portusjacksoni) and 18 bluespotted flathead (Platycephalus caeruleopunctatus) were monitored using acoustic telemetry around a designed AR in 38-m depth near Sydney, Australia. Fiddler rays exhibited an average short-term presence of 43% at the AR, and 26% over the ~20-month monitoring period, which was significantly higher than the other two species. Fish tagged at the AR showed high affinity to the site at which they were tagged compared with fish tagged on natural reef. All three species moved frequently between the AR and the other reefs in the area, indicating that the AR may increase the connectivity between adjacent habitats and aid the dispersion of benthic species. The moderate presence at the AR suggests that these species may contribute to some biomass production at this AR by incorporating this reef in their natural range.

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31

Harding, D. J., R. G. Dwyer, T. M. Mullins, M. J. Kennard, R. D. Pillans, and D. T. Roberts. "Migration patterns and estuarine aggregations of a catadromous fish, Australian bass (Percalates novemaculeata) in a regulated river system." Marine and Freshwater Research 68, no. 8 (2017): 1544. http://dx.doi.org/10.1071/mf16125.

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Catadromous fish species require adequate flows to migrate between fresh and saltwater habitats to reproduce. However, artificial barriers and flow alteration affect fish populations by reducing habitat connectivity and disrupting movement cues. In regulated rivers, it is critical that migratory flow requirements are quantified to optimise water allocation for multiple users. In the present study, we assessed the migratory timing, flow and estuarine aggregation requirements for Australian bass (Percalates novemaculeata). Over 2 years, 66 bass were tracked using an acoustic receiver array in the Logan River (Qld, Australia). Bass performed large-scale downstream movements in response to elevated winter flows (40 and 108m3 s–1), which facilitated migration to the lower estuary, where salinity conditions were appropriate for spawning. Bass migrations occurred only when gonads were mature, despite large flows providing opportunities for movement outside this period. Experimental flow releases from an impoundment (2.1m3 s–1) during winter did not elicit a migratory response. Connectivity between upstream and estuarine habitats was reduced by the presence of instream weirs, with downstream movement across weirs occurring only when sufficient flow magnitude was achieved (>76.1m3 s–1). These findings are relevant for water resource managers formulating environmental flow rules for catadromous fish species in systems with multiple instream artificial barriers.

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32

Putra, Ridwan Manda, Sukendi Sukendi, Dewita Dewita, Budijono Budijono, and Syahril Nedi. "Pengkayaan Sumberdaya Ikan di Oxbow Melalui Penerapan Artifisial Habitat Oleh Nelayan Desa Rantau Baru Kecamatan Pangkalan Kerinci Kabupaten Pelalawan Riau." CANANG: Jurnal Pengabdian Masyarakat 3, no. 2 (2023): 43–48. http://dx.doi.org/10.52364/canang.v3i2.36.

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Abstract (sommario):

This community dedication is aimed at informing the community about the creation of a new fish habitat by floating a set of artificial habitat units in the selected zone based on oxbow batimetry, so that the fish resources in the oxbows remain available. The dedication activities were carried out in the Rantau Baru Village, Pangkalan Kerinci district of Pelalawan Regency, and the delivery of material was carried out on August 2, 2023. There are 30 participants in this selection, consisting of the village equipment and the oxbow fishermen in the New Rantau Village. The materials to be provided for this dedication are: (a) Oxbow and its uses; (b) biodiversity of fish and public waters; (c) threats to fish biodiversity; (d) artificial habitat; and (e) methods of creation, operation, and maintenance of artificial habitat. The method used in the implementation of this activity is to survey the field first, then conduct deliberations in the form of lectures and interactive discussions, followed by demonstrating the artificial creation of habitats and placing the tools in the oxbow. The results of the evaluation of the change in knowledge carried out on 30 participants in the service to the community showed that 5 people (16.7%) have been able to absorb the material given with the preaching very well, 13 people (43.3%) can absorb materials given with good preaching, 10 people (33.3%) can absorb material with sufficient preaching, and 2 people (6.7%) could absorb material with less preaching. As for the impact on implementation in the field, there has been a process of dissemination of knowledge to fishermen carried out by community leaders. So that the diversity of fish in public waters (especially the oxbow lake) that exists in the Rantau Baru Village can be well awakened.

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33

Meyer-Gutbrod, Erin L., Li Kui, Mary M. Nishimoto, Milton S. Love, Donna M. Schroeder, and Robert J. Miller. "Fish densities associated with structural elements of oil and gas platforms in southern California." Bulletin of Marine Science 95, no. 4 (2019): 639–56. http://dx.doi.org/10.5343/bms.2018.0078.

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Abstract (sommario):

There are thousands of offshore oil and gas platforms worldwide that will eventually become obsolete, and one popular decommissioning alternative is the "rigs to reefs" conversion that designates all or a portion of the underwater infrastructure as an artificial reef, thereby reducing the burden of infrastructure removal. The unique architecture of each platform may influence the size and structure of the associated fish assemblage if different structural elements form distinct habitats for fishes. Using scuba survey data from 11 southern California platforms from 1995 to 2000, we examined fish assemblages associated with structural elements of the structure, including the major horizontal crossbeams outside of the jacket, vertical jacket legs, and horizontal crossbeams that span the jacket interior. Patterns of habitat association were examined among three depth zones: shallow (<16.8 m), midwater (16.8–26 m), and deep (>26 m); and between two life stages: young- of-the-year and non-young-of-the-year. Fish densities tended to be greatest along horizontal beams spanning the jacket interior, relative to either horizontal or vertical beams along the jacket exterior, indicating that the position of the habitat within the overall structure is an important characteristic affecting fish habitat use. Fish densities were also higher in transects centered directly over a vertical or horizontal beam relative to transects that did not contain a structural element. These results contribute to the understanding of fish habitat use on existing artificial reefs, and can inform platform decommissioning decisions as well as the design of new offshore structures intended to increase fish production.

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34

Salmon, Quentin, Samuel Westrelin, Julien Dublon, Etienne Abadie, and Jean-Marc Baudoin. "Artificial floating littoral zones: a promising nursery to support Pike (Esox lucius) in reservoirs." International Journal of Limnology 60 (2024): 22. http://dx.doi.org/10.1051/limn/2024022.

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Abstract (sommario):

The use of water resources in reservoirs leads to artificial water level fluctuations sometimes with extreme amplitudes and frequencies. These artificial fluctuations homogenize littoral habitats and often make macrophytes disappear. Consequently, spawning and refuge-nursery habitats become scarce which is critical for phytophilous species such as Northern Pike (Esox lucius) whose populations decline. Quite recently, floating artificial structures have emerged as a mitigation solution. However, the design of these structures is relatively simplistic and only consists in a simple 2D-floating mat of vegetation. Their effectiveness to support fish populations, especially pike in regulated reservoir, by providing suitable habitats for spawning, refuge and nursery remains poorly documented. Here we conceived 3D artificial Floating Littoral Zones (FLOLIZ) that mimic a natural littoral zone to support both pike spawning and juvenile growth (helophytes, hydrophytes, specific shelter areas). To assess their effectiveness, three structures of 70 m2 area and 1 m deep were installed in September 2018 in a French reservoir subject to extreme water level fluctuations. Visual surveys carried out in spring and summer by snorkelling over 2019–2023 highlighted an annual recurrence of juvenile pike in FLOLIZ, but also a higher abundance than in control stations. The maximum number of individuals observed simultaneously on the same structure was 14. Even if it cannot be asserted that pike spawned in FLOLIZ, these results highlight that FLOLIZ can provide refuge and nursery habitats for juvenile fish in reservoirs with poor littoral habitats.

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35

Miguet, Paul, Laurence Tissot, Patrick Lambert, Ine S. Pauwels, and Samuel Westrelin. "An individual-based model to predict the spatial distribution of northern pike, European perch and pikeperch from habitat use in a reservoir subject to water level fluctuations." Hydroécologie Appliquée 24 (2024): 1. http://dx.doi.org/10.1051/hydro/2024001.

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Abstract (sommario):

Reservoirs are subject to artificial water level fluctuations leading to a degradation of the littoral habitats. This often results in reduced productivity and biological diversity, particularly for fish. The development of predictive tools of fish population dynamics linked to habitat characteristics can help to optimize management actions such as habitat restoration. We developed a spatially explicit individual-based model, the 3Plake model, which predicts the spatial distribution of three fish species, northern pike, European perch and pikeperch, over seasons and diel cycles according to their habitat use. The model was calibrated with an accurate description of habitat and high spatial and temporal resolution data of fish movements in a French reservoir. The model calibration is only based on a species-specific coefficient of habitat selectivity. It was chosen to (i) match the observed and simulated traveled hourly and daily distances and (ii) minimize a metric quantifying the distance between observed and simulated density maps. The 3Plake model correctly simulated the means of traveled distances and the species distributions along the year on the study reservoir. The minimal input required (HSI maps and maximum distance range) allows its easy implementation on other reservoirs and fish species. It could be used to assess the impact of habitat restoration or water level management scenarios on fish distribution.

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36

Park, Joo Myun, Ralf Riedel, Hyun Hee Ju, and Hee Chan Choi. "Fish Assemblage Structure Comparison between Freshwater and Estuarine Habitats in the Lower Nakdong River, South Korea." Journal of Marine Science and Engineering 8, no. 7 (2020): 496. http://dx.doi.org/10.3390/jmse8070496.

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Abstract (sommario):

Variabilities of biological communities in lower reaches of urban river systems are highly influenced by artificial constructions, alterations of flow regimes and episodic weather events. Impacts of estuary weirs on fish assemblages are particularly distinct because the weirs are disturbed in linking between freshwater and estuarine fish communities, and migration successes for regional fish fauna. This study conducted fish sampling at the lower reaches of the Nakdong River to assess spatio-temporal variations in fish assemblages, and effects of estuary weir on structuring fish assemblage between freshwater and estuary habitats. In total, 20,386 specimens comprising 78 species and 41 families were collected. The numerical dominant fish species were Tachysurus nitidus (48.8% in total abundance), Hemibarbus labeo (10.7%) and Chanodichthys erythropterus (3.6%) in the freshwater region, and Engraulis japonicus (10.0%), Nuchequula nuchalis (7.7%) and Clupea pallasii (5.2%) in the estuarine site. The fish sampled were primarily small species or the juveniles of larger species at the estuary region, while all life stages of fishes were observed at the freshwater habitats. The diversity patterns of fish assemblages varied greatly according to study site and season, with higher trends at estuarine sites during the warm-rainy season. No significant difference in diversity between freshwater and estuarine sites during the cold-dry season were found. Multivariate analyses of fish assemblage showed spatial and seasonal differences of assemblage structures. Higher effects of between-site variability but not within seasonal variability at each site were observed. Variations in assemblage structures were due to different contributions of dominant species in each habitat. Common freshwater species characterized the fish assemblage in the freshwater region, while marine juveniles were significantly associated with the estuarine habitat. The results from the ecological guild analyses showed distinct ecological roles for freshwater and marine species, and overlapping roles for fish sampled at the fishways. The lower reaches of the Nakdong River are an important ecosystem for both freshwater and marine juveniles. Nakdong River estuarine residents and migrant fishes, however, have been negatively affected by the construction of the weir (gravity dam), due to the obstruction to migration from and to freshwater habitats. Conservation and management policies aimed at minimizing anthropogenic influences on estuary ecosystems should focus on evaluating ecological functions of estuary weirs.

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37

Selfati, Mohamed, Najib El Ouamari, Philippe Lenfant, et al. "Promoting restoration of fish communities using artificial habitats in coastal marinas." Biological Conservation 219 (March 2018): 89–95. http://dx.doi.org/10.1016/j.biocon.2018.01.013.

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38

Parkos, Joseph J., and Joel C. Trexler. "Origins of functional connectivity in a human-modified wetland landscape." Canadian Journal of Fisheries and Aquatic Sciences 71, no. 9 (2014): 1418–29. http://dx.doi.org/10.1139/cjfas-2013-0553.

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Abstract (sommario):

Spatial heterogeneity in habitat conditions within a landscape should influence degree of movement of species between natural and artificial environments. For wetland landscapes, this functional connectivity was predicted to emerge from the influence of spatiotemporal patterns of depth on permeability of habitat edges and distance and directedness of cross-habitat dispersal. We quantified how connectivity between canals and marshes of the Florida Everglades varies with species and landscape patterns bordering canals by using radio telemetry to measure movement of a native (Florida largemouth bass, Micropterus salmoides floridanus) and a nonnative species (Mayan cichlid, Cichlasoma urophthalmus) common to canals. Both species moved similar distances inside canal networks, but Mayan cichlids dispersed outside of canals more frequently, at shallower conditions, and over greater distances than Florida largemouth bass. As topographic relief increased in marshes bordering canals, dispersal between these habitats decreased in distance and became more directed, with Florida largemouth bass sensitive to depth variability at a smaller spatial scale than Mayan cichlids. The way fish traits interact with submerged landscape structure to influence connectivity can serve as a basis for predicting potential impacts of artificial habitats that arise from dispersal outside their borders.

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39

Santos, Miguel N., Francisco Leitão, Ana Moura, Marco Cerqueira, and Carlos C. Monteiro. "Diplodus spp. on artificial reefs of different ages: influence of the associated macrobenthic community." ICES Journal of Marine Science 68, no. 1 (2010): 87–97. http://dx.doi.org/10.1093/icesjms/fsq139.

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Abstract (sommario):

Abstract Santos, M. N., Leitão, F., Moura, A., Cerqueira, M., and Monteiro, C. C. 2011. Diplodus spp. on artificial reefs of different ages: influence of the associated macrobenthic community. – ICES Journal of Marine Science, 68: 87–97. Although artificial reefs (ARs) have been deployed and studied worldwide, few studies have attempted to link the benthic community to fish populations. Three AR fish species (Diplodus bellottii, D. sargus, and D. vulgaris) were tested for the influence of the macrobenthic community at three similar ARs deployed in 1990, 1998, and 2002 off the Algarve (southern Portugal). Diplodus sargus density and biomass differed across ARs, and for D. bellottii and D. vulgaris, higher densities and biomass were observed between the oldest and the youngest ARs. The total available benthic biomass did not differ across habitat age, but the composition of macrofauna differed between older and the most recently deployed AR. The results underscore the importance of within-reef-age benthic composition variability as a determinant factor in structuring local fish populations. As the Algarve AR complex consists of reefs deployed at different times and having different benthic communities, management needs to focus more effort on conserving entire habitats rather than exclusively on maintaining the sustainability of fish resources. Hence, management plans for these areas need to be developed on a site-specific basis, according to the fish and macrobenthic community specificities.

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40

Dinh, Quang Minh, Lam Thanh Tran, Tuyet Thi Minh Tran, Diem Kieu To, Tien Thi Kieu Nguyen, and Dinh Dac Tran. "Variation in diet composition of the mudskipper, Periophthalmodon septemradiatus, from Hau River, Vietnam." Bulletin of Marine Science 96, no. 3 (2020): 487–500. http://dx.doi.org/10.5343/bms.2018.0067.

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Abstract (sommario):

Periophthalmodon septemradiatus (Hamilton, 1822) is a mudskipper of the Mekong Delta that can be found along estuaries and lower reaches of rivers. In the present study, we determined diet and feeding ecology of this species by analyzing the contents within the stomachs of 1360 fish samples collected from August 2017 to July 2018. Data analysis suggested that P. septemradiatus is a carnivorous fish. We found six main food item categories: small fishes, prawns (Acetes spp.), crabs (Uca spp.), molluscs, ants (Dolichoderus sp.), and detritus. Both males and females at different sizes, seasons, and habitats ingest primarily Dolichoderus sp., secondarily detritus, and rarely other prey. Diet composition was similar between sexes but varied according to fish size, season, and habitat. Dolichoderus sp. and detritus regulate the spatial variation of food composition. Our findings contribute to future artificial cultivation for conservation.

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41

Auger, Pierre, Christophe Lett, Ali Moussaoui, and Sylvain Pioch. "Optimal number of sites in artificial pelagic multisite fisheries." Canadian Journal of Fisheries and Aquatic Sciences 67, no. 2 (2010): 296–303. http://dx.doi.org/10.1139/f09-188.

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Abstract (sommario):

We present a mathematical model of artificial pelagic multisite fisheries. The model is a stock–effort dynamical model of a fishery subdivided into artificial fishing sites such as fish-aggregating devices (FADs) or artificial habitats (AHs). The objective of the work is to investigate the effects of the number of sites on the global activity of the fishery. We consider a linear chain of fishing sites in which fish are harvested by fishing vessels and a free stock that is unattached to the sites and not exploited. Fish movements between the sites and the free stock, as well as vessel displacements between the sites, are assumed to take place at a faster time scale than the variation of the stock and the change of the fleet size. We take advantage of these two time scales to derive a reduced model governing the dynamics of the total fish stock and the total fishing effort. We show that there exists an optimal number of fishing sites that maximizes the total catch at equilibrium. We finally extend the model to the situation in which both fish attached to the sites and fish in the free stock are exploited.

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42

Wang, Zhenhua, Yong Chen, Shouyu Zhang, Kai Wang, Jing Zhao, and Qiang Xu. "A comparative study of fish assemblages near aquaculture, artificial and natural habitats." Journal of Ocean University of China 14, no. 1 (2014): 149–60. http://dx.doi.org/10.1007/s11802-015-2455-x.

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43

Joubert, Etienne, Robin P. M. Gauff, Benoist de Vogüé, Fabienne Chavanon, Christophe Ravel, and Marc Bouchoucha. "Artificial fish nurseries can restore certain nursery characteristics in marine urban habitats." Marine Environmental Research 190 (September 2023): 106108. http://dx.doi.org/10.1016/j.marenvres.2023.106108.

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44

Edwards, Rhys A., and Stephen D. A. Smith. "Subtidal assemblages associated with a geotextile reef in south-east Queensland, Australia." Marine and Freshwater Research 56, no. 2 (2005): 133. http://dx.doi.org/10.1071/mf04202.

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Abstract (sommario):

In marine habitats, the use of geotextile materials as a ‘soft-engineering’ solution is increasingly being considered as an alternative to hard structures. However, very little is known about biological assemblages that develop on geotextile structures. This study provides the first ecological comparison of subtidal assemblages between Narrowneck Artificial Reef (NAR), a geotextile reef in south-east Queensland, Australia, and three nearby natural reefs. Benthic community structure, fish assemblages and habitat complexity were compared between reef types using an asymmetrical design. Although natural reefs supported distinct biotic assemblages, as a class, these reefs differed significantly from NAR. The artificial reef was dominated by macroalgae and supported fewer benthic categories, whereas the natural reefs were characterised by a diverse range of sessile invertebrates. Benthic and demersal fish assemblages were less diverse on NAR, but pelagic fish assemblages were similar on both reef types. The substratum of NAR was less complex than that of the natural reefs; this physical variable was correlated with some of the differences in benthic communities and benthic and demersal fish assemblages. It is likely that the key determinants of the biotic patterns observed in this study are interactions between the age of NAR and the physical properties of geotextile substratum.

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45

Becker, Alistair, Matthew D. Taylor, and Michael B. Lowry. "Monitoring of reef associated and pelagic fish communities on Australia’s first purpose built offshore artificial reef." ICES Journal of Marine Science 74, no. 1 (2016): 277–85. http://dx.doi.org/10.1093/icesjms/fsw133.

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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.

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Brown, Larry R., and Anne M. Brasher. "Effect of predation by Sacramento squawfish (Ptychocheilus grandis) on habitat choice of California roach (Lavinia symmetricus) and rainbow trout (Oncorhynchus mykiss) in artificial streams." Canadian Journal of Fisheries and Aquatic Sciences 52, no. 8 (1995): 1639–46. http://dx.doi.org/10.1139/f95-758.

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We studied the effects of predatory Sacramento squawfish (Ptychocheilus grandis) on habitat choice of juvenile California roach (Lavinia symmetricus), adult roach, and juvenile rainbow trout (Oncorhynchus mykiss) in artificial streams. In single-prey trials, the proportion of fish found in pool habitat declined in the presence of squawfish for juvenile roach (from 0.55 to 0.00), adult roach (from 0.88 to 0.13), and juvenile rainbow trout (0.70 to 0.15). The presence of squawfish did not affect the use of riffle and edge habitats. Of the fish found in shallow water, the proportion found in edge habitat declined from juvenile roach (0.95) to adult roach (0.80) to juvenile rainbow trout (0.23). We also conducted experiments designed to simulate invasion of an area by squawfish, in which adult roach and juvenile rainbow trout were tested together in the presence and absence of squawfish. The proportion of prey in pool habitat in the presence of squawfish was greater in the two-prey trials than in the single-prey trials for both adult roach (0.31 and 0.13, respectively) and juvenile rainbow trout (0.33 and 0.15, respectively). These results support field evidence that squawfish are an important force in determining the spatial structure of native stream fish assemblages.

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47

Kallianiotis, Athanasios A., Chryssa Anastasiadou, and Ioannis E. Batjakas. "Catalyzing Conservation: An Analysis of Fish Stock Dynamics in a Marine Protected Area before and after Artificial Reef Deployment." Coasts 4, no. 1 (2024): 150–67. http://dx.doi.org/10.3390/coasts4010009.

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The marine ecosystem’s balance is crucial for sustaining biodiversity and supporting fisheries. Marine protected areas have been increasingly used to enhance marine habitats, yet their impact on fish populations remains a topic of debate. This study focuses on a marine protected area in Kitros, Pieria, in Greece, where an artificial reef was constructed, to understand its influence on coastal fish populations. The objectives were to investigate the changes in fish biomass and abundance, comparing the data from periods before and after the construction of an artificial reef. This research compares the data between 2007 and 2008 with the data between 2016 and 2017, collected with bottom trawl surveys strategically executed prior to and after the artificial reef’s installation. Fish species captured were identified, with their lengths and masses measured. The findings indicate an increase in the biomass and abundance of certain fish species after artificial reef deployment, notably the commercially significant Mullus barbatus and Pagellus erythrinus. The artificial reef in Kitros, Pieria, with its surrounding marine protected area appears to have had a positive impact on the local fish populations over the years, suggesting that it can contribute to marine conservation and fishery enhancement. These results underscore the potential of artificial reefs as tools for marine ecosystem management, offering insights for policymakers and environmentalists into coastal resource management.

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48

Ross, EP, J. Butler, and TR Matthews. "Examining the ecological function of structure: species assemblages at casitas and coral heads in the Lower Florida Keys." Marine Ecology Progress Series 681 (January 6, 2022): 169–83. http://dx.doi.org/10.3354/meps13926.

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Casitas are artificial structures used widely in the Caribbean to facilitate the harvest of spiny lobsters by divers. Casitas are often used by many non-target species, and therefore have the potential to increase local species diversity and mitigate the loss of natural habitats. Their ecological impact, however, is largely unknown. We examined the distribution of benthic habitat and the abundance and diversity of fish and motile invertebrates at casitas (artificial structures), coral heads (natural habitat with vertical structure >15 cm high), and low-relief hardbottom (natural habitat with vertical structure <15 cm high). Casitas and coral heads exhibited similar habitat features and fish and invertebrate species assemblages. Low-relief hardbottom sites had significantly less abundant and diverse fish and invertebrate species assemblages than at either structure. The only significant difference observed between casitas and coral heads was the abundance of lobsters. Lobsters were found in significantly greater numbers at casitas than at either coral heads or on low-relief hardbottom. Determining how an increased concentration of lobsters at casitas affects the local ecology is complex, but our data suggest that the presence of lobsters in such large aggregations at casitas did not alter the surrounding flora and fauna. In regions with limited shelter, species composition and ecological function at casitas are similar to those at coral heads. This study shows that casitas may be efficient dual-purpose devices; that is, they function not only as lobster fishing gear, but also as the ecological equivalent of coral heads in shelter-limited habitat.

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49

Granneman, Jennifer E., and Mark A. Steele. "Fish growth, reproduction, and tissue production on artificial reefs relative to natural reefs." ICES Journal of Marine Science 71, no. 9 (2014): 2494–504. http://dx.doi.org/10.1093/icesjms/fsu082.

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Abstract The extent to which artificial reefs may be useful for mitigation of environmental impacts, fisheries management, and conservation depends in part upon how well the organisms that live on them fare. We tested whether fish living on artificial reefs were in similar condition (weight-at-length), grew, foraged, reproduced, and produced tissue at rates similar to those on natural reefs. We studied five artificial–natural reef pairs spread over >200 km in the Southern California Bight. Underwater visual transects were used to quantify density and size structure of four target species (Paralabrax clathratus, Paralabrax nebulifer, Semicossyphus pulcher, and Embiotoca jacksoni), which were also collected to measure foraging success, condition, growth, reproductive output, and tissue production. Generally, fish living on artificial reefs fared as well or better than those on natural reefs, with some exceptions. Semicossyphus pulcher fared better on artificial reefs, having higher foraging success, fecundity, densities, and tissue production. Embiotoca jacksoni grew faster on natural reefs, and P. nebulifer was in slightly better condition on natural reefs. Total fish tissue production tended to be higher on artificial reefs than on natural reefs, though this pattern was not evident on all reef pairs. Tissue production was positively correlated with the abundance of large boulders, which was higher on artificial reefs than natural reefs. The similar or greater production of fish tissue per cubic metre on artificial reefs relative to natural reefs indicates that these artificial habitats are valuable in producing fish biomass. Fish living on artificial reefs fared as well as those living on natural reefs, indicating that well-designed artificial reefs can be useful tools for mitigation, conservation, and fisheries management.

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50

Hristov, Kroum Kroumov. "Observations of Cyclope neritea Linnaeus 1758 Breeding Behaviour in Artificial Habitat." Indian Journal of Pure & Applied Biosciences 10, no. 1 (2022): 19–28. http://dx.doi.org/10.18782/2582-2845.8868.

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Cyclope neritea Linnaeus 1758 is a popular Mediterranean Sea gastropod mollusk. A scavenger associated with shellfish farming, and used for population genetics studies and monitoring of environmental pollution. The aim is to evaluate C. neritea’s propagation under long-term artificial condition. C. neritea is maintained in 34 ppt substitute sea-water, along with copepods, Tigriopus californicus Baker 1912 at 25 oC and 12/12 hr light/dark cycle. It is an oviparous marine gastropod laying scattered single-egg-containing capsules. The females with retarded egg-capsule deposition eat the egg immediately after deposition. Normal capsules are not attacked. Juveniles supplement their diet with eggs of their kind regardless of the stage of development. Intra- and extra-capsular development and growth were observed. Its transient longevity reasons the work for optimising the conditions for the successful maintenance, and popularising it for the ornamental fish habitats.

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