Marine Artificial Reef Research and Development: Integrating Fisheries Management Objectives

<em>Abstract</em>.—Twenty artificial reefs were deployed early in October 2005 approximately 20 km south of Dauphin Island, Alabama (USA), in the Hugh Swingle General Permit Area. Each reef consisted of 12 concrete blocks (20 cm long × 20 cm wide × 41 cm high) arranged on a plywood base (1.5 m<sup>2</sup> )and deployed on the bottom, 20 m deep. To quantify the epibenthic assemblage on the reefs, four removable bricks were attached to the reefs. Ten reefs were coated with copper-based, anti-fouling paint and 10 reefs were unpainted. Fish and epibenthic assemblages were compared between reef treatments (i.e., with and without copper-based paint). Reefs were surveyed 1 week after deployment in October 2005, then again in December 2005, May 2006, August 2006, and December 2006. During each survey, two scuba divers visually estimated the densities of all fish species and removed one of the removable bricks to identify and quantify the epibenthic organisms. The epibenthos (coverage area, biomass, diversity, species richness) and fish assemblages (total fish density, species diversity, species richness) were greater on unpainted reefs. Red Snapper <em>Lutjanus campechanus</em>, wrasses <em>Halichoeres </em>spp., Bank Sea Bass <em>Centropristis ocyurus</em>, and Atlantic Spadefish <em>Chaetodipterus faber </em>had higher densities on unpainted reefs. This study indicated that recruitment of fishes to artificial reefs was not just attraction to structure, but that growth of epibenthic assemblages had a significant influence on recruitment.

<em>Abstract</em>.—Reef-fish assemblage structure was compared among multiple artificial and geologic (i.e., naturally occurring hard bottom) habitats in the northeastern Gulf of Mexico during 2014–2016 as part of a larger fishery-independent survey. Baited remote underwater video systems equipped with stereo cameras were deployed (<em>n </em>= 348) on 11 habitat types, classified through interpretation of side-scan sonar imagery. In the video samples, 11,801 fish were enumerated. Nonparametric analysis of reef-fish assemblages detected four clusters related to habitat; assemblages associated with geologic habitats were distinct, whereas the remaining three clusters represented groupings of artificial habitats of different size, scale, and complexity. While many species, including Vermilion Snapper <em>Rhomboplites aurorubens </em>and Red Snapper <em>Lutjanus campechanus</em>, were observed in greater numbers on artificial reef habitats, most species were observed in all habitats sampled. Among artificial reef habitats, the habitat cluster consisting of unidentified depressions, unidentified artificial reefs, construction materials, and reef modules was similar to geologic habitats in supporting larger individuals, specifically Gray Triggerfish <em>Balistes capriscus </em>and Red Snapper. In contrast, the habitat cluster consisting of smaller, generally solitary chicken-transport cages was inhabited by smaller individuals, including smaller Red Snapper. Although geologic reefs are the predominant reef habitat throughout much of the eastern Gulf, artificial reefs are important locally, especially in the Florida Panhandle. Accordingly, continued incorporation of artificial reef habitats within large-scale fishery-independent monitoring efforts is critical to the accurate assessment of the status of reef-fish stocks on broad spatial scales.


<em>Abstract</em>.—Visual census scuba surveys (<em>n </em>= 87) were used to compare fish assemblages among three artificial reef types: big reefs (e.g., ships), tank reefs (i.e., U.S. Army tanks) and small reefs (e.g., metal cages and concrete pyramids), over three locations on the continental shelf (inner shelf, 18–26-m depths; mid-shelf, 26–34-m depths; outer shelf, 34–41-m depths) from April 20, 2012 to November 30, 2015 in the northeast Gulf of Mexico. These surveys identified 66 fish taxa (lowest taxon: 58 species, five genera, three families), and 65 taxa were used in community comparisons. Artificial reefs were dominated by Red Snapper <em>Lutjanus campechanus </em>(35.3% of total fish observed), Tomtate <em>Haemulon aurolineatum </em>(22.4%), Vermilion Snapper <em>Rhomboplites aurorubens </em>(19.5%), Atlantic Spadefish <em>Chaetodipterus faber </em>(7.0%), Greater Amberjack <em>Seriola dumerili </em>(3.0%), and Gray Triggerfish <em>Balistes capriscus </em>(1.8%). These six most abundant species comprised 89% of the total number of individuals observed. Red Snapper and Greater Amberjack mean sizes (total length mm) were larger at big reefs, Vermilion Snapper and Atlantic Spadefish were larger at tank reefs, and Tomtates were larger at small reefs. Red Snapper, Atlantic Spadefish, and Greater Amberjacks were larger at reefs on the outer shelf, and Red Snapper, Tomtates, Vermilion Snapper, Atlantic Spadefish and Greater Amberjacks were larger in the spring. Richness and Shannon–Wiener diversity indices were higher on big reefs and tank reefs compared to small reefs. Evenness, richness, and Shannon–Wiener diversity were lower in winter compared to other seasons. Fish assemblages, based on Bray–Curtis similarities, were different among reef type, location, and season, but no interactions effects were identified. In the present study, fish assemblages on big reefs were more similar to assemblages on tank reefs in comparison to small reefs. The larger size, longer life span, and relative stability of the big reefs and tank reefs were the reef attributes most likely responsible for these assemblage associations. Similarly, more stable conditions at deeper depths (less affected by tropical storms) and proximity to deepwater reef fish communities (e.g., pinnacle reefs) most likely influenced the increased assemblage diversity on the artificial reefs at outer-shelf locations. Diversities and densities were highest during the fall. This was most likely due to increased recruitment of tropical species and new age-0 recruits that were spawned during the same year. The attributes of all artificial reefs are not identical; consequently, it is important for managers to consider how reef type, shelf location, and season affect each species’ affinity and association with artificial reefs.


<em>Abstract</em>.—Identifying morphometrics, age composition, and growth of Red Snapper <em>Lutjanus campechanus </em>(Poey, 1860) in the Gulf of Mexico is crucial for management of this valuable species. Red Snapper are highly associated with artificial reefs situated off the coast of Texas. Artificial reefs, two in federal waters (offshore) and two in state waters (inshore), were sampled quarterly from December 2014 through December 2016. Characteristic differences in age and growth patterns at inshore and offshore sites and across sampled sites were compared. Mean ± standard deviation was calculated for total length (TL), weight, and biological age. Red Snapper collected averaged 464.5 ± 92.6 mm in TL, 1.62 ± 1.03 kg, and 3.8 ± 1.5 years. Significant differences in TL, weight, and age were observed across sites but not between inshore and offshore locations. In comparing 12 previous Red Snapper length-at-age (0–25 years) studies across the Gulf of Mexico, results were similar except for two studies significantly different from one another, but none with respect to our study. Our findings suggest that Red Snapper populations are young and restricted to one or two spawning years before capture on artificial reefs. Continued management of fisheries associated with these reefs are necessary to increase the stock and eventually lead to robust and sustainable fisheries.


2006 ◽  
Vol 63 (5) ◽  
pp. 775-784 ◽  
Author(s):  
Dan Wilhelmsson ◽  
Torleif Malm ◽  
Marcus C. Öhman

Abstract A significant expansion of offshore windpower is expected in northwestern Europe in the near future. Little is known about the impacts it may have on the marine environment. Here, we investigate the potential for wind turbines to function as artificial reefs and fish aggregation devices (FADs), i.e. whether they would locally increase fish densities or alter fish assemblages. Fish communities and habitat composition were investigated using visual transects at two windpower farms off the southeastern coast of Sweden, central Baltic Sea. Fish abundance was greater in the vicinity of the turbines than in surrounding areas, while species richness and Shannon–Wiener diversity (H′) were similar. On the monopiles of the turbines, fish community structure was different, and total fish abundance was greater, while species richness and diversity (H′) were lower than on the surrounding seabed. Blue mussels and barnacles covered most of the submerged parts of the turbines. On the seabed, more blue mussels and a lesser cover of red algae were recorded around the power plants than elsewhere. Results from this study suggest that offshore windfarms may function as combined artificial reefs and fish aggregation devices for small demersal fish.


1981 ◽  
Vol 59 (9) ◽  
pp. 1635-1646 ◽  
Author(s):  
Dominique Gascon ◽  
Roberta A. Miller

We investigated the structure of a temperate nearshore fish community by examining the development of fish assemblages on small artificial reefs of concrete blocks constructed in two series 6 months apart. In each series, a species equilibrium, of approximately six species, was rapidly reached within 6 months. Eight of the 30 species which had colonized the reefs from the surrounding rocky habitats were common on the reefs. Both juveniles and adults of all species were present, except for the rockfishes (Sebastes spp.) which were represented only by young individuals (1 to 3 years of age). Tagging indicated that the bottom-dwelling species (Gobiidae, Cottidae) remained permanently on the reefs, whereas a seasonal turnover in rockfish occurred.The communities inhabiting the reefs usually did not differ from each other within each series, whereas significant differences occurred between series. This difference was attributed to the differential colonizing ability of species. No evidence of interspecific competition was apparent among the species inhabiting the reefs.The results are discussed in light of some current models of coral reef fish community structure. Some possible factors affecting the differences observed between tropical and temperate waters are also discussed.


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


2017 ◽  
Vol 68 (10) ◽  
pp. 1955 ◽  
Author(s):  
James A. Smith ◽  
William K. Cornwell ◽  
Michael B. Lowry ◽  
Iain M. Suthers

Artificial reefs are a widely used tool aimed at fishery enhancement, and measuring the scale at which fish assemblages associate with these artificial habitat patches can aid reef design and spatial arrangement. The present study used rapidly deployed underwater video (drop cameras) to determine the magnitude and spatial scale of associations between a fish assemblage and a coastal artificial reef. Count data from drop cameras were combined with distance and bathymetry information to create a suite of explanatory generalised linear mixed models (GLMMs). The GLMMs showed that artificial reefs can influence surrounding fish abundance, but that the magnitude and scale is species specific. Three of the eight taxonomic groups examined showed a positive association with the artificial reef (with model fit poor for the remaining groups); and depth and bottom cover were also influential variables. The spatial scales of these associations with the artificial reef were small, and it was generally the presence of reef (i.e. a reef bottom type) that explained more variation in fish abundance than did distance to reef. The schooling baitfish yellowtail scad was an exception, and had elevated abundance >50m from the artificial reef. Further distribution modelling of artificial reefs will benefit species-specific design and management of artificial reefs.


Author(s):  
Diogo Fonseca Da Rocha ◽  
Marcos Alberto Lima Franco ◽  
Pedro Vianna Gatts ◽  
Ilana Rosental Zalmon

Artificial reefs (ARs) are often used to improve fishing and, consequently, the economy of a region. However, the way in which the species use the reefs may vary between fish assemblages. An assessment was made of the influence of an AR complex on the transient fish population off the northern coast of Rio de Janeiro state and, therefore, two control areas were sampled. Gillnets were used to capture individual fish in six sampling surveys. Cumulative abundance and biomass curves (ABC) were used to assess the possible effects of the reefs on the community's functional structure. In the dry season, during which the influence of the Paraíba do Sul River is smaller, a larger richness of r-strategy species and juveniles of K-strategy species was observed in the reef area compared with the control areas, suggesting that the AR acts as a protective environment for these species. During the lower river discharge period the results indicated a potential disturbance in the functional structure of the AR fish community and, therefore, a less stable environment relative to the control areas. This ‘instability’ warrants a positive connotation, as it indicates that the artificial reefs are harbouring species that are particularly sensitive to predation, making the reef a powerful tool for maintaining these populations on the northern coast of Rio de Janeiro.


2017 ◽  
Vol 5 (2) ◽  
pp. 145
Author(s):  
Gisela Awuy ◽  
Ari B. Rondonuwu ◽  
Alex Denny Kambey

The aim of this research is to determine the species richness, individual abundance, and the ecology index of the coral fishes on the artificial reef of Kareko waters,  District of North Lembeh - Bitung City. The data is collected using “Visual Census” technique by scuba diving. The amount of the reef fishes found in the artificial coral reefs were 53 species. The abundance species in the artificial reefs which made from metal were 34 species and which made from concrete were 35 species. The total of number individuals of coral fishes from 47 species is 210.50 individuals/30m2. The total density was 7,017 individuals/m2. The highest relative density on iron-made reefs was found in Dascyllus trimaculatus (15.73%) and and which made from concrete were Dascyllus reticulatus (10.85%).  Based on H’, H’max, and H’min, the diversity Index  of coral fishes in both artificial reefs including high.Keywords : Coral Fishes, Artificial Reef, Kareko ABSTRAKTujuan penelitian ini yaitu untuk mengetahui kekayaan spesies, kelimpahan individu, dan indeks ekologi ikan karang pada terumbu buatan di Perairan Kareko. Kecamatan Lembeh Utara, Kota Bitung. Pengambilan data dilakukan dengan menggunakan teknik “Sensus Visual” dengan melakukan penyelaman SCUBA. Jumlah spesies ikan karang yang ditemukan pada terumbu buatan yaitu 53 spesies. Kekayaan spesies di terumbu buatan yang terbuat dari besi berjumlah 34 spesies, sedangkan di terumbu buatan beton berjumlah 35 spesies. Kelimpahan individu total ikan karang dari 47 spesies yaitu 210,50 individu/30 m2 sedangkan kepadatan/densitas total adalah 7,017 individu/m2. Kepadatan relative tertinggi untuk terumbu buatan besi ditemukan pada jenis Dascyllus trimaculatus (15,73%) dan untuk terumbu buatan beton ditemukan pada jenis Dascyllus reticulatus (10,85%). Berdasarkan nilai H’, H’max, and H’min, indeks keanekeragaman ikan karang pada kedua jenis terumbu buatan tergolong tinggi.Keywords : Coral Fishes, Artificial Reef, Kareko


Sign in / Sign up

Export Citation Format

Share Document