252 JARDEWESKI.cdr
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252 JARDEWESKI.cdr
Journal of Coastal Research 1210 - 1214 SI 39 ICS 2004 (Proceedings) Brazil ISSN 0749-0208 Fish Assemblage on Artificial Reefs in South Brazilian Coast C. L.F. Jardeweski† and T. C. M. de Almeida‡ Laboratório de Ecologia de Comunidades Universidade do Vale do Itajaí Centro de Ciências Tecnológicas da Terra e do Mar, Itajaí, 88330 002, Brazil. † [email protected] ‡ [email protected] ABSTRACT JARDEWESKI, C. L. F. and ALMEIDA, T. C. M., 2006. Fish assemblage on artificial reefs in south brazilian coast. Journal of Coastal Research, SI 39 (Proccendigs of the 8th International Coastal Symposium), 1210 - 1214. Itajaí, SC, Brazil, ISSN 0749-0208. The introduction of artificial reefs in coastal environments has been widely used with diverse objectives, such as: fisheries and marine habitat enhancement, protection of shorelines, delimitation and protection of marine areas of ecological relevance. The present study has as main objective the comparison of the structure and composition of associated ictiofauna in artificial reefs, introduced in two distinct places: close and distant from the rocky shore. Two groups of three structures (Reef BallÔ) were disposed in the Island João da Cunha/SC, a group located near the rocky shore and the other with a distance of 50 meters. The strategy of visual census was used in the accompaniment of ictiofauna, done by linear transects in the mentioned areas. The fishes were counted and identified to the lesser possible taxon. A total of 19 species were identified, Stegastes fuscus was the most abundant in the area close to the rocky shore and Haemulon sp for the distant points. The diversity was larger in the reefs near to the rockyshore (0,693 1,925 nats) then in the distant points (0,60 1,332 nats). The total abundance also presented a similar standard pattern to the diversity, being higher near the rockyshore. Two distinct species associations were identified, one in distant reef points composed by Batigobius soporator, Haemulon sp and Anisotremus virginicus; and another association near the rockyshore, composed by Sparissoma sp, Epinephelus marginatus, Sphoeroides testudineus, Eucinostomus sp, Stegastes fuscus, Diplopodus argenteus, Pareques acuminatus and Epinephelus morio. The presence and the distance of the rocky shore, was shown as an important factor, in the colonization of artificial reefs. However, it must be considered, that the available time for the colonization also must interveine in this process. ADDITIONAL INDEX WORDS: Artificial reef, assemblage, reef fishes. INTRODUCTION Artificial Reefs (AR) are characterized as structures manufactured in concrete, wood, pneumatics and rocks, placed in the aquatic environment. They can have diverse functions, serving as tools of great utility, when their placement in the environment is planned and well sized. These structures provide new niches for marine life, attracting many species of invertebrates and fishes (CAR and HIXON, 1997). Many species use them for shelter from currents and predators, as well as utilizing the fouling fauna and flora as a food source (SPANIER, 1994; SAUL and CUNNINGHAM, 1997; GODOY et al., 2002; RILOV and BENAYAHU, 1998). The most notable alteration following the implantation of these structures is the increase in fish catches, this being one of the principal reasons for the utilization of artificial reefs (PHONGSUWAN et al., 1994; ZALMON et al., 2002). The observation that fish are attracted to objects placed in water thigmotrophism (OREN, 1968), such as the tuna catches near floating objects in the open ocean (FAD Fish-Attracting Devices) and prosperous fishing near shipwrecks (SUMMERHAYES and THORPE, 1996; BOHNSACK et al, 1997) is among the principal factors which encouraged the utilization of AR (SVANE and PETERSEN, 2001). In Brazil, BRANDINI (1998) and ATHIÊ (1997) carried out revisions regarding the registration and the utilization of artificial reefs. The utilization of AR was registered back in the 17th century by the Tupi and Tamoio Indian Nations and since the 1970s structures constructed with rocks, mangrove tree branches and concrete have been utilized by small fishing communities in the northeast of Brazil (CONCEIÇ Ã O, 1998). In recent years, many research groups have concentrated their studies on the effects of these structures in the marine environment (ATHIÊ , 1999), a program for the application of these structure along the entire coast of the state of Parana (southern Brazil) appearing at the end of the last century (BRANDINI, 199). However, little is known regarding those aspects related to the structure of the fish communities and the associated species in this new substrate, when compared with natural substrates, such as a rocky shore. The objective of the present study is to describe and compare the structure and composition of the fish communities of artificial reefs and a nearby rocky shores, located on an island off the southern coast of Brazil. METHODS StudyArea The structures were placed near the João da Cunha Island (Porto Belo Island) at coordinates 27°08'S and 48°32'W (Figure 1). The region is characterized as a stable and well sheltered bay. The island, together with the continent, form a channel influenced principally by tides. In the bay, there are some areas of mollusk cultivation which favor a reduction in hydrodynamism, which increases the sedimentation rate and reduces the visibility of the water. The sediments in the region, in general terms, is characterized by a mixture of sand and mud, which also contributes to the reduction in visibility. The shallow sheltered bays, in the state of Santa Catarina, are little affected by the seasonal intrusion of subtropical waters of the south and provide a habitat for around half of the known reef fish species of the Brazilian continental platform (FLOETER et al., 2001). The coast of Santa Catarina is the southern limit of the reef fishes distribution in the Brazilian province, with the occurrence of rocky shores inhabited by algae and sponges (FLOETER, op cit). Three areas were monitored during the experiment, a rocky shore (CN), considered as the control, near the area where the reefs were placed and with similar characteristics; reefs, positioned at two distinct sites: one near the island rocky shore (RD) and another placed further from the island (RF). In each of the areas where the artificial reefs were sunk, 3 Reef BallÔ structures were placed. Census Technique The monitoring of the fish community was effected by way Journal of Coastal Research, Special Issue 39, 2006 1211 Fish Assemblage on Artificial Reefs BRAZIL Figure 1. Localization of Porto Belo Island. of visual censuses carried out along linear transects (WATSON and QUINN II, 1997; Ferreira et al., 1993), of dimensions 20m x 2m, randomly placed at the above locations, in a 10 minute period. The censuses were carried out monthly from March to August 2003, by means of SCUBA diving. In each census, all fishes were counted along the transects, and the identifications were carried out during the census up to the lowest possible taxon. The three areas were monitored on the same day to avoid great variation in the environmental conditions. DataAnalysis The data were organized in the form of a matrix, in which the columns represented the different censuses in each month and at each place, and the lines represented the species. For the characterization of the fish community structure, the ShannonWeaver (Ln) diversity index, the equitability and the total abundance of fishes, were utilized (PIELOU, 1984). The community structure was compared by means of analysis of variance considering the locations as the source of variation (UNDERWOOD, 1994). The species composition at the three areas was compared through the analysis of similarities applied over a matrix of dissimilarity. The faunistic similarity was calculated from the Bray-Curtis coefficient (ANOSIM). The correspondence analysis was applied to the identification of the fish species associations (LEGENDRE and LEGENDRE, 1998). Table 1. Percent frequency of species occurrence in censuses carried out at the rocky shore (CN), the Artificial Reefs near the rocky shore (RD) and the Artificial Reefs distant from the rocky shore (RF). Family Carangidae Bleniidae Diodontidae Gerreidae Gobiidae Haemulidae Ostraciidae Pomacentridae Scaridae Scianidae Scorpaenidae Serranidae Sparidae Tetraodontidae Total Species Species Caranx sp Ophioblennius atlanticus Diodon sp Eucinostomus sp Batigobius soporator Anisotremus virginicus Haemulon sp Acanthostracion quadricornis Stegastes fuscus Abudefduf saxatilis Sparisoma sp Pareques acuminatus Scorpaena sp Epinephelus marginatus Epinephelus niveatus Myctiroperca acutirostris Diplectrum sp Diplopodus argenteus Sphoeroides testudineus CN --16.7 16.7 --16.7 16.7 83.3 --83.3 33.3 --33.3 ------100 50.0 83.3 100 12 Journal of Coastal Research, Special Issue 39, 2006 RD 16.7 ------16.7 16.7 50.0 16.7 100 --33.3 --16.7 50 16.7 100 66.7 100 16.7 14 RF ------33.3 50.0 33.3 33.3 --16.7 ------16.7 ----83.3 50.0 ----8 1212 Jardeweski and Almeida 35 Abundância Total Diversidade (Ln) 2 1,5 1 0,5 0 30 25 20 15 10 5 0 RD RF RD CN RF 0,95 8 7 6 5 4 3 2 1 0 Equitabilidade Número de Espécies CN Locais Locais 0,9 0,85 0,8 0,75 0,7 RD RF RD CN RF CN Locais Locais Figure 2. Community structure parameters obtained for the three study locations. RESULTS A total of 19 species distributed among 14 different families, were identified. The most abundant species were Sparidae Diplodus argenteus, Serranidae Myctiroperca acutirostris, Haemulidae Haemulon sp and Pomacentridae Stegastes fuscus, with these species totaling 78% of the total fishes registered in the censuses. The fish diversity showed significant differences between the 3 locations (F=8.858; p= 0.0029) with the lowest being found for the furthest reefs. The same pattern was obtained for the total abundance of fishes (F=6.646; p= 0.0086) and for the equitability were differences between the 3 locations not detected (Figure 2). The species composition differed for the 3 locations (RGlobal=0.451; p=0.1%), (Table 2). The highest diversity, abundance of fishes and number of species were found for RD and CN and the lowest values for these community structure parameters were obtained for RF (Figure 2). The correspondence analysis permitted the extraction and interpretation of two factorial axes, which explained a total of 46% of the specific abundance variation for the sites and the sample months. It is worth noting that the aspects related to the Fish Assemblage on Artificial Reefs in South Brazilian Coast temporal variations are considered in this analysis. Axis 1, responsible for 24% of the variation, was formed by positive coordinates of the censuses carried out at RF in the months of July and August, and by the negative coordinates of the censuses carried out at the same location in the months of March, April and May. Axis 2, responsible for 22% of the variation, was formed principally by the negative coordinates of CN in the months of March, April, May, July and August (Figure 3). Axis 1 showed a seasonal variation in RF, while axis 2 showed the different species associations found between RF and, CN and RD. Table 2. Significance level of groups. Number >= Observed R Statistic 5.2 4.2 Scorpaena sp 3.1 2.1 The occurrence of species which form small shoals such as Diplodus argenteus at RD and CN, and Haemulon sp at all Groups Eucinostomus sp Axis 2 DISCUSSIONS locations may have influenced the density results, generally in the visual census the most abundant species are overestimated (WATSON and QUINN II, 2001; FERREIRA et al., 1993). In the species association, the highest number found at RD, was due to the proximity to the rocky shore (CN), which may be functioning as a source area for new organisms. It is worth mentioning that the inner reef area (RD) is a sheltered location with greater stability in relation to the hydrological aspects of the environment, providing a direct migration of new individuals. The location where the ReefBallsÔ were positioned at RD would be at the interface of the consolidated substrate of the rocky shore with the muddy-sand of the infralitoral zone, where we can verify a greater variety of habitats and niches available. Along with this high heterogeneity found, the artificial reefs increase the habitat complexity, allowing greater chances of finding abundances and diversities higher than those verified at other locations. As in the case of SANTOS and MONTEIRO (1997), a higher similarity in the fish assemblage of the artificial reefs was expected as a consequence of the insertion of reefs on unconsolidated sea bottoms. In fact, the reefs fixed to soft substrates created a discontinuity in the bottom biocenose promoting the appearance of new communities of benthic organism, which favor the enrichment and diversification of the original fish community. It is worth mentioning that RF is found near a tidal canal with little protection against the action of local currents, this directly influencing the offering and migration of new individuals. The Diploplectrum sp fuscus Sparisoma sp -2.1Stegastes-1.04 Significance Possible Level % Permut. Actual Permut. Batigobius soporator 1.1 Mictiroperca acutirostrix Diplopodus argenteus Anisotremus virginicus 1.1 2.1 3.1 Epinephelus marginatus Haemulon aurolineatum Abudefduf saxatilis Sphoeroides testudineus -1.04 Equetus acuminatus RD RF 1 0,559 0,2 462 462 RD CN 7 0,239 1,5 462 462 RF CN 1 0,587 0,2 462 462 -2.1 Axis 1 Figure 3a. Diagram of correspondence analysis. Journal of Coastal Research, Special Issue 39, 2006 4.2 5.2 Fish Assemblage on Artificial Reefs RF Ago 2.4 RF Jul 1.9 1.4 Axis 2 1.0 0.5 RF Jun RD Mar RD AgoRD Mai CN Ago CN Jun -0.5 RD Jul -1.0 0.5 RD Jun CN Abr RD Abr CN Jul 1.0 1.4 1.9 2.4 CN Mai -0.5 CN Mar -1.0 Axis 1 Figure 3b. Diagram of correspondence analysis. instability of the hydrological aspects, combined with endogenic and biological aspects (e.g. greater availability of food and more shelter) may control the distribution of local fauna of reef fishes (GODOY, 2002). As BELLAN and BELLAN SANTINI (1991) and BOMBACE (et al, 1994) have shown, the attraction capacity of reefs is regulated by their size and density in the environment, and greater diversities are found in artificial reefs near natural reefs, as in the case of RD when compared to RF. The distance of the natural reefs probably represent an important role in the recruitment of the artificial reefs, since the natural substrate may constitute an important source of juvenile migration, settling of larvae and spores. On the other hand MACARTHUR and WILSON (1967) noted that despite the number of colonizing species being limited by the size of the reef and its distance from the source of new individuals, estimates regarding the number of species do not indicate anything regarding the composition of the established assemblages. Therefore we may state that the reduced number of species found at RF was influenced mainly by the distance from a source of new individuals and its exposure to the actions of local currents. Another important aspect to be mentioned is that RF is still in the initial process of succession, which directly reflects in the behavior of the community structure, since from March to August the number of species found increased from 4 to 8, doubling the parameters found, and in the same way diversity and density were also influenced by the same inherent process of succession. For RF we may verify seasonability which was shown by the species association found in the fall for Anisotremus virginicus, and in the winter for Eucinostomus sp. The other species Batigobius soporator and Scorpaena sp identified in the species association for RF (Figure X) are classified as cryptic, and may have been underestimated in the visual census (WILLIS, 2001; FERREIRA et al., 1993), and they can therefore not be considered as strong indicators of seasonability. ACKNOWLEDGEMENTS This work is part of a graduation work concluded thanks to CTTMAR, UNIVALI and INSTITUTO ECOPLAN. We also would like to thank Dr. Tito Almeida for their valuable critical analisys, contributions and suggestions. LITERATURE CITED ARAUJO, F. G. and BROTTO, D. S., 1999. Uso de estruturas artificiais como habitat por organismos marinhos. VII Congresso Latino Americano sobre Ciências do Mar, Anais, 46-47. ATHIÊ , A. A. R., 1999. Colonização e Sucessão Ecológica de 1213 Peixes em Recifes Artificiais no Canal de São Sebastião, Litoral Norte do Estado de São Paulo Brasil. Dissertação de Mestrado, IOUSP, 192p. ATHIÊ , A. A. R., 1999. Recifes Artificiais: Ciência e Tecnologia Emergente no Brasil. VII Congresso Latino Americano de Ciências do Mar, anais, 54-56. BOHNSACK, J. A.; ECKLUND, A. M. and SZMANT, A. M. , 1997. Artificial Reef Research: Is There More Than The Attraction-Production Issue? Fisheries, Special Issue on Artificial Management, vol 22, nO. 4. BRANDINI, F. A, 1998. Utilização de Recifes Artificiais para o Desenvolvimento de Comunidades Marinhas e seus Benefícios Sócio Econômicos. IV Simpósio de Ecossistemas Brasileiros: Mesa Redonda, Águas de Lindóia, São Paulo. CARR, M. H. and HIXON, M. A., 1997. Artificial Reefs: The Importance of Comparisons with Natural Reefs. Fisheries: Special Issue on Artificial Reef Management, vol 22 n O. 4, 28-33. CASTRO, J.J.; SANTIAGO, J.A. and HERNÁ NDEZ-GARCÍA, V, 1999. Fish Associated With Fish Aggregation Devices off the Canary Islands (Central-East Atlantic). Scientia Marina, 63 (3-4): 191-198. CONCEIÇ Ã O, R. N. de L. and MONTEIRO, C., 1998. Recifes Artificiais Marinhos - Incrementando a Pesca Nas Comunidades Costeiras do Ceará UFCE. Disponível em: < http://www.biotecnologia.com.br/bio/6_b.htm. FERREIRA, C.E.L.; GONÇ ALVES, J.E.A. and COUTINHO, R., 1993. Metodologias em Estudos de Comunidades de Peixes em Costões Rochosos: Questões Básicas e Fundamentais. III Simpósio de Ecossistemas da Costa Brasileira,ACIESP. FLOETER, S. R.; GUIMARÃ ES, R. Z. P.; ROCHA, L. A.; FERREIRA, C. E. L.; RANGEL, C. A. and GASPARINI, J. L., 2001. Geographic Variation in Reef-Fish Assemblages Along The Brazilian Coast. Global Ecology and Biogeography 10, 423-431. FROESE, R. and PAULY, D. Editors. 2003. FishBase. World Wide Web electronic publication. www.fishbase.org, version 24 September 2003. GODOY, E. A. S.; ALMEIDA, T. C. M. and SALMÓ N, I. R., 1998. Fish Assemblages and Environmental Variables on an Artificial Reef Rio de Janeiro, Brazil. Journal of Marine Science, 59. GODOY, E. A. de S., 2000. Fauna Associada a Bancos Artificiais de Sargassum Furcatum na Ilha de Cabo Frio RJ, Brasil. Dissertação de Mestrado UENF, 65p. GODOY, E. A. de S. and COUTINHO, R., 1998. Can Artificial Beds of Plastic Mimics Compensate for Seasonal Absence of Natural Beds of Sargassum furcatum? Journal of Marine Science 59, 111-115. LEGENDRE, L.; LEGENDRE, P., 1999. Numerical ecology. developments in environmental modelling, 3. Elsevier Sci. Publ. Company, 419 p. OREN, O.H., 1968. Artificial Reefs A Short Review And Appeal, Fao (Food And Agriculture Organization Of The United Nations) Rome, December. ORNELLAS, A. B. and R. COUTINHO., 1998. Spatial and temporal patterns of distribution and abundance of a tropical fish assemblage in a seasonal Sargassum bed, Cabo Frio Island, Brazil. J. Fish Biol. (53) Sup.A: 198-208. PHONGSUWAN, N.; CHANSANG, H. and SATAPOOMIN, U. , 1994. Colonization of Fouling Communities and Associated Fauna at the Artificial Reefs. The Effect of Artificial Reef Installation on the Biosocioeconomics of Small-scale Fisheries in Ranong Province, Thailand. 17-27. PIELOU, E. C. 1969. An Introduction To Mathematical Ecology. Wiley, New York, P. 286. REEFBALL, 1998. Programa Recifes Artificiais Marinhos, Uma Proposta De Conservação Da Pesca Artesanal Na Costa Do Estado Do Paraná, Instituto Ecoplan e Centro De Estudos Do Mar CEM/Ufpr. Disponível Em: <http://www.reefball.com/ecoplan/index.html>, 14/10/1998. Journal of Coastal Research, Special Issue 39, 2006 1214 Jardeweski and Almeida RILOV, G. and BENAYAHU, Y., 2000. Fish Assembalge On Natural Versus Artificial Reefs: The Rehabilitation Perspective. Marine Biology. SANTOS, M. N. and MONTEIRO, C. C., 1997. The Olhão Artificial Reef System (South Portugal): Fish Assemblages and Fishing Yield. Fisheries Research 30, 33-41. SAUL, A.C. and CUNNINGHAM, P. T. M., 1997. Use Of Space By Fish In Artificial Reefs In Brazil: An Experimental Approach. VII Colacmar, P. 418-419, Santos, São Paulo. SPANIER, E.; TOM, M.; PISANTY, S. and ALMOG-SHTAYER, G., 1990. Artificial Reefs In The Low Productive Marine Environments Of The Southeastern Mediterranean. Marine Ecology, 11(1): 61-75. SUMMERHAYES, C.P. and THORPE, S.A., 1996. Oceanography an Illustrated Guide, Southampton-Uk, Manson Publishing P.259-272. SVANE, I. and PETERSEN, J. K., 2001. On The Problems of Epibioses, Fouling and Artificial Reefs, a Review. Marine Ecology 22, 169-188. UNDERWOOD, A. J., 1997. Experiments In Ecology. Cambridge University Press. New York, Usa, 504 P. WATSON, R. A. and QUINN II, T.J., 1997. Performance of Transect and Point Count Underwater Visual Methods. Ecological Modelling 104, 103-112. WILLIS, T. J., 2001. Visual Census Method Underestimate Density and Diversity of Cryptic Reef Fishes. Journal of Fish Biology 59, 1408-1411. ZALMON, I. R.; NOVELLI, R.; GOMES, M. P. and FARIA, V. V., 2002. Experimental Results of an Artificial Reef Programme on the Brazilian Coast, North of Rio de Janeiro. Journal of Marine Science 59, 83-87. ZAR, J. H., 1984. Bioestatistical analysis. Prentice Hall Ed. 718 pp. Journal of Coastal Research, Special Issue 39, 2006
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