The effect of an artificial reef system on the transient fish assemblages – south-eastern coast of Brazil

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.

2006 ◽  
Vol 54 (4) ◽  
pp. 183-191 ◽  
Author(s):  
Werther Krohling ◽  
Daniel Shimada Brotto ◽  
Ilana Rosental Zalmon

The northern coast of Rio de Janeiro State lacks natural consolidate substrates, making it a proper environment to the development of researches using artificial structures. After studies about the type of substrate, concrete seems to be the most appropriate for studying fouling community development. This research was carried out to investigate the functional role of biofouling in the development of the ichthyic community in the north of Rio de Janeiro State. Percentage data of the epibenthic organisms' coverage and samples of the fish community with gillnet and visual census showed that biofouling in artificial reefs might have more than one functional role, acting as a facilitator in the recruitment of fish species and as a link in the trophic marine chain. Through the increase of localized structural complexity provided by the reef itself and by the fouling organisms which act as "engineering species", additional protection options are offered to the ichthyic community, especially recruits. Also, the epibiont biomass represents an important link in the food web, acting either as a direct source or in the transference of energy to higher trophic levels. Through the relationship between the ichthyic and fouling communities we concluded that the functional role of the latter in artificial reef habitats could be characterized mainly as shelter and feeding grounds for few fish species.


2005 ◽  
Vol 65 (1) ◽  
pp. 67-76 ◽  
Author(s):  
A. G Ferreira ◽  
A. L. S. Machado ◽  
I. R. Zalmon

Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) concentrations were determined by ICP-AES in Ostrea equestris from three beaches (Barra do Furado, Buena, and Ponta do Retiro) on the northern coast of Rio de Janeiro State. The average concentration was 0.8 ± 0.18, 0.4 ± 0.21, 58 ± 25.6, 249 ± 52.3, 11 ± 1.31, 0.55 ± 0.16, 0.13 ± 0.11, and 1131 ± 321 µg.g-1 dry weight for Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn respectively. Significant spatial variation (p < 0.05) between the samples areas occurred for Cr, Pb, and Zn with higher values in Barra do Furado; and for Cu in Ponta do Retiro. Significant temporal variations (p < 0.05) were observed for all metals except Cu. Temporal variability may be related to changes in the inputs of metals associated with suspended particles. Concentrations were similar to those found in areas under low pollution impact, except for Zn, the high concentrations of which probably reflect the physiological characteristics of these organisms.


2004 ◽  
Vol 47 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Alexandre Gomes Ferreira ◽  
André Luís dos Santos Machado ◽  
Ilana Rosental Zalmon

Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) concentrations were studied in Perna perna from three beaches (Barra do Furado, Buena and Ponta do Retiro) on the northern coast of Rio de Janeiro State by ICP-AES. The average concentration was 0.3 ± 0.04 (Cd); 1.9 ± 0.6 (Cr); 6.1 ± 0.7 (Cu); 1,130 ± 113 (Fe); 22 ± 3.2 (Mn); 9.3 ± 4.6 (Ni); 0.4 ± 0.2 (Pb); 44 ± 5.8 (Zn) µg.g-1 dry weight. There were no significant difference for almost all the studied metals in relation to sex. Although, significant spatial variations (p < 0.05) occurred for Cr, Pb and Ni with higher values for Barra do Furado. Temporal variations were significant (p < 0.05) at the three beaches, however, no trends of accumulation were observed. The metal concentrations were similar to areas under low pollution impact, except for Fe, which was probably due to the local substrates enriched in iron oxides.


2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Juliano Silva Lima ◽  
Camilah Antunes Zappes ◽  
Ana Paula Madeira Di Beneditto ◽  
Ilana Rosental Zalmon

Abstract: The objective of this study is to describe the ethnoecological aspects, valorization, and commercialization of target species caught by artisanal fishers on the northern coast of Rio de Janeiro, southeastern Brazil. The data were obtained through semi-structured interviews conducted with 60 fishers from the fishing community of Guaxindiba (21°29'S, 41°00'W), which is associated with the Z-1 fishers' colony. Eighty-nine species were cited by the fishers and 44.1% are important commercial fish in the region. The fishers cited five distinct zones used to fish: border zone (68 species), estuary (41 spp.), artificial reef (27 spp.), "malacacheta" (24 spp.), and open ocean (10 spp.). The fishery resources were classified according to their gastronomic and economic characteristics: primary fish (35 spp.), secondary fish (32 spp.), mixed fish (10 spp.), discarded fish (7 spp.), and fish used as bait (5 spp.). The price of the target species increases along the production chain due to the greater number of people involved, processing costs, and improvement of the product. The data from this study can contribute to local fisheries management and point out to the use of artificial reefs in the maintenance of fishery resources in northern Rio de Janeiro.


Author(s):  
N. A. A. Zamzuri ◽  
M. I. Hassan

Abstract. Fish are the part of marine ecosystem and play an important role as contributors of nutrients and dependent on the ecosystem which is affected by the parameters to provide the right conditions for reproduction. Artificial reefs were being applied as an approach to sustain food security. Food security is a major concern for all countries in the face of population increase and diminishing water supplies including in the fisheries sector. Hence, artificial reefs become one of the methods to improve the preservation of fish supplies. Suitable environment for fish ground breeding area need to be identified in order to place the artificial reef. Therefore, this study is proposed to locate the potential fish ground breeding area in Terengganu, Malaysia based on localized criteria which is suitable to place the artificial reefs by examining the parameters in the area. Parameters that have been studied were water temperature, water salinity, water acidity, chlorophyll concentration and dissolve oxygen. Those parameters have their own criteria that represent the suitability for fish population. Localized data have been applied in order to analyse and support localized criteria for this study area. To locate the potential fish ground breeding area, Geographic Information System (GIS), Multi-criteria Decision Analysis (MCDA), Spatial Interpolation and Weighted Analysis have been applied. For MCDA, Analytical Hierarchy Process (AHP) has been used to get the weightage of the parameters by running Pairwise Comparisons between the selected parameters using AHP software, Expert Choice. Then, those parameters weightage were applied in weighted analysis to identify the potential ground breeding area. At the end of this study, final map showing the location for fish ground breeding area. The final output resulted potential location for fish ground breeding area in four classes which are very high, high, medium and low potential area. This study may facilitate the decision makers to place the artificial reefs in potential area to increase fish population.


<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.


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.


2011 ◽  
Vol 92 (6) ◽  
pp. 1289-1299 ◽  
Author(s):  
Ilana Rosental Zalmon ◽  
Catarina Dalvi Boina ◽  
T.C.M. Almeida

There have been many efforts to appraise the extent to which artificial reefs affect the surrounding community, but few studies addressed whether benthic assemblages change with distance from the reef. We experimentally assessed the relationship between infauna abundance and richness with increased distance (0, 5, 25, 50, 100 and 300 m) from reefballs deployed on a flat and homogeneous bottom, 9-m deep, on the north coast of Rio de Janeiro, south-eastern Brazil. Benthic taxon richness and abundance varied significantly between surveys with higher values in February 2007. Both numerical indicators changed similarly with distance, but more noticeably between 300 m and the other distance treatments where abundance was highest. A non-metric multidimensional scaling ordination revealed that macrobenthic assemblages were very heterogeneous with significant differences between surveys but not among sampling distances. A canonical correspondence analysis including species, distances and sediment variables showed that the distances 5, 25 and 100 m were related to organic matter and mud (fine sediment), while 0 and 300 m distances were more related to the non-organic variables, such as the percentage of gravel, sand and calcium carbonate. Spatial variations in the parameters of the sediment alone did not explain the distribution of the associated infauna, given the similarity of the community at different distances. It is suggested that the influence of artificial reefs is quickly dissipated due to strong bottom sea currents, indicating a reduced impact or influence of these reefs on the surrounding infauna.


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