6166, Campinas, , Säo Paulo, Brazil Published online: 28 Jan 2009.

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1 This article was downloaded by: [ ] On: 22 March 2014, At: 08:17 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: Registered office: Mortimer House, Mortimer Street, London W1T 3JH, UK Italian Journal of Zoology Publication details, including instructions for authors and subscription information: The artisanal fishery of the River Piracicaba (São Paulo, Brazil): Fish landing composition and environmental alterations Renato A.M. Silvano a & Alpina Begossi a a Núcleo de estudos e Pesquisas Ambientais, Universidade Estadual de Campinas, POBox 6166, Campinas, , Säo Paulo, Brazil Published online: 28 Jan To cite this article: Renato A.M. Silvano & Alpina Begossi (1998) The artisanal fishery of the River Piracicaba (São Paulo, Brazil): Fish landing composition and environmental alterations, Italian Journal of Zoology, 65:S1, , DOI: / To link to this article: PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content ) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at

2 Ital. J. Zool., 65, SuppL (1998) The artisanal fishery of the River Piracicaba (São Paulo, Brazil): fish landing composition and environmental alterations RENATO A. M. SILVANO ALPINA BEGOSSI Núcleo de estudos e Pesquisas Ambientais, Universidade Estadual de Campinas, POBox 6166, Campinas, Säo Paulo (Brazil) ABSTRACT Large reservoirs are increasing in number in South America and Brazil, and are exploited by fishers. The River Piracicaba receives several pollutants discharged from industries and residences, and had its downstream portion dammed in This study is about the giilnet fishery located at the impounded portion of the River Piracicaba, and the possible influences of habitat alterations on the fish catch composition. Fish landings were recorded three days each month between October 1994 and September Data on the weight of fishes caught (kg per species) in 248 fish landings were collected. The catch of the large migratory catfishes (Siluriformes) decreased in the last 10 years, probably because of the interruption of their migratory route by the impoundment. Migratory Characiforms, on the other hand, have increased in the fishery. The river organic pollution probably favoured the spread of fishes that can adapt to low oxygen conditions. Forest clearance, which reduces forestry food resource availability, could be decreasing omnivorous fishes in the fishery. Fish landings in the River Piracicaba fishery suffered change in its composition in the past 11 years. The environmental alterations that had occurred in the Piracicaba River basin, like impoundment, pollution, and deforestation, can be important factors influencing such changes. INTRODUCTION Tropical artisanal fisheries furnish a considerable amount of animal protein to people living in developing countries (Bayley & Petrere, 1989). These fisheries are usually less impacting on fish communities than large commercial and industrial fisheries, which employ a greater fishing effort (Welcomme, 1985). South America presents a great diversity of freshwater fishes, that forms a huge available fishing stock (Böhlke et al, 1978; Lowe-McConnell, 1984). Large reservoirs constructed mainly for hydroelectric power generation are spreading in South America and in Brazil, and are fished by fishers (Petrere, 1996). Impoundment of a large river causes several habitat alterations (Baxter, 1977). Such alterations could be deleterious to fish communities in these impounded rivers (Barthem et al, 199D, reducing the productivity of the fishery (Beamesderfer et al, 1995; Ribeiro et al, 1995). The River Piracicaba is 115 km long and is one of the main constituents of the Piracicaba River Basin, with a draining area of km 2 (CETESB, 1996). In 1995, the Basin had a total water demand of 7.41 m 3 -s, divided between urban (34%), irrigation (16%), and industrial (50%) uses (CBH-PCJ, 1996). During this same period, the Basin received discharges of effluents from 194 industries and of domestic sewage from 40 cities, of which only 13 possess some sewage treatment system (CETESB, 1996). The downstream portion of the Piracicaba River was dammed in 1962 as a result of the construction of Barra Bonita reservoir. Small fishing villages with active fishermen are located along the reservoir banks (Torloni et al, 1993; Silvano, 1997). There is a scarcity of published works concerning the fishery performed by these people on an extremely modified river. The majority of data concerning the impounded portion of the River Piracicaba fishery is based on unpublished Theses or technical reports. This study documents the giilnet fishery of the impounded portion of the River Piracicaba. We compare our data with other fishery studies from the last 11 yrs, verifying the changes in the fish catch composition in the light of the environmental changes suffered by the river. KEY WORDS: South America - Freshwater fishes - Reservoirs - Fishery - Impoundment - Deforestation - Pollution. ACKNOWLEDGEMENTS Thanks are given to the fishermen from Ponte de Santa Maria da Serra and Tanquà, for their friendship and kindly collaboration with this work to L. Sanchez, who introduced me to the fishermen, to O. T. Oyakawa, for help with fish species identifications, to I. Sazima, for help with fish species identifications and valuable suggestions, to M. Petrere Jr. and M. M. Habib for valuable suggestions, to CAPES and FMB for grants to the senior author, and to FAPESP and Padct-Finep for financial field trip support. (Received 28 August Accepted 4 February 1998) MATERIALS AND METHODS Barra Bonita reservoir is located in Sào Paulo State, in southeastern Brazil (Fig. 1). Fish landings were recorded at two small fishing villages, located in the portion of the Barra Bonita reservoir that corresponds to the River Piracicaba: the Ponte de Santa Maria da Serra and Tanquà (Fig. 1), six days per month and monthly between October 1994 and September Weights of fishes caught (kg per species) were recorded. The fish landings of the two localities were analyzed together. Fishes that comprised the bulk of the catches were weighted separated, the others mixed. This action may have underestimated the biomass of uncommon and smaller species. Through comparisons with other studies, we document a brief historical change in the composition of fish landings.

3 528 R. A. M. SILVANO, A. BEGOSSI Impoundment Fig. 1 - Southeastern Brazilian region and Piracicaba River basin with indication of the two fishing villages studied, Tanquä (1) and Ponte de Santa Maria da Serra (2). RESULTS AND DISCUSSION Our study considers only the gillnet fishery, because it is the main fish gear employed by the fishermen (Silvano, 1997). We obtained fish landings from 248 samples in 1994 and 1995, a period that corresponds to the more recent data on the Barra Bonita reservoir (impounded River Piracicaba) catch composition (Table I). Looking at the results from other studies conducted in 1985 and 1995 in the same region (Table II), we observed temporal changes in fish relative abundances. These changes can be related to several factors: alterations in the fishing gear, the commercial demand for some fishes, or to modifications in the fish community composition, among others. The fishing gear (gillnets) was always the same. We believe that 11 years was too short a period to note significant changes in the fish preferences by the consumers. So, alterations in the fish community must be a more plausible factor. We analyzed these possible alterations, taking account the influences of the environmental modifications suffered by the Piracicaba River, such as the impoundment, water pollution, and deforestation. Ichthyofaunal inventories conduced in the Barra Bonita 1996 reservoir showed a reduction from 59 (CETESB, 1986) to 35 species (Castro, 1997). According to Castro (1997), this impoverishment in the fish community can be explained by the impacts derived from the impoundment and by the antropic action in the basin. In the upstream portion of the River Piracicaba, the artisanal fishery was almost eliminated. This was mainly because of a diminution of great migratory catfishes and water pollution, the latter generates an avoidance for the fishes by the people (Silvano, 1997). Impoundment of the River Piracicaba may be the major factor accounting for the reduction of the Pintado, Pseudoplatystoma coruscans (Agassiz) (Tables I - II). Another large catfish, the Jau, Paulicea lutkeni (Steindachner) does not appear in fish landings, but was mentioned by the fishermen as being abundant in the past (Silvano, 1997). Large catfishes usually occupy the main channels of the great rivers (Lowe-McConnell, 1987). These fishes make extensive migrations for hundreds of kilometers and are very sensitive to the effects of dams that interrupt their migratory routes (Barthem et al., 1991). For example, following the Tucurui reservoir formation in the River Tocantins (east Brazilian Amazon), the P. coruscans and P. lutkeni were eliminated from the fishery (Ribeiro et al., 1995; Petrere, 1996). Some migratory Characiforms are possibly able to cope with the new reservoir conditions. The corimbatâ Prochilodus lineatus Steindachner and dourado Salminus maxillosus Valenciennes relative biomasses increased between 1985 and 1995 (Tables I - II). Considering that these species need to migrate upriver to reproduce (Godoy, 1975; Agostinho et al., 1995), they probably migrate upstream from the dam in the River Piracicaba. This can be possible because of approximately 100 km of unimpounded river and the presence of numerous small tributaries. The tributaries allow the migratory fish to reproduce in impounded waterbeds (Agostinho et al, 1995). Prochilodus lineatus is detritivorous (Fugi et al., 1996), and an increase in its abundance in the reservoir fishery could be related to the great quantity of food provided by the decomposition of submerged logs and vegetation (Welcomme, 1985; Agostinho et al., 1995; Ribeiro et al., 1995). The impoundment of a river usually changes its fish community, favouring the proliferation of species well adapted to lenthic conditions (Junk et al., 1981; Santos, 1995; Petrere, 1996). Another impoundment effect in the River Piracicaba can be the increase in the abundance of fishes like the Corvina, Plagioscion squamosissimus (Heckel), Traira Hoplias malabaricus (Bloch), and the Cascudos, family Loricariidae, which are well suited to lenthic habitats (Fink & Fink, 1979). Plagioscion squamosissimusis also an important fish resource in other lenthic habitats, such as Amazon lakes and northeastern Brazilian reservoirs (Petrere, 1978, 1996). Water pollution A considerable portion of fish biomass landed at the Barra Bonita reservoir belongs to species that possess some tolerance to low oxygen concentrations, like P. lineatus (Parma-de-Croux, 1995), Hoplias malabaricus (Rantin et al, 1993) and Cascudo, (Loricariidae) (Fink & Fink, 1979) (Table I). This can be an effect of organic water pollution to the fish community. The Piracicaba River basin received, in 1995, a total amount of organic pollution of t OBD 5 day, of which 117 t

4 ARTISANAL FISHERY OF THE RIVER PIRACICABA 529 TABLE I - Fish landings species composition in biomass at the River Piracicaba, in Popular names Scientific names Family TW b P c Corimba Prochilodus lineatus Corvina Plagioscion squamosissirnus Mandi Pimelodus maculatus and Pimelodus fui Cascudo mainly Liposarcus aff. anisitsi and Hypostomus spp Lambari Astyanax bimaculatus, A. schubarti, and Moenkhausia intermedia 3 Traira Hoplias malabaricus Caborja Hoplosternum litoralle Piranha Serrasalmus spilopleura Piava Leporinus spp and Schizodon intermedius Piapara Leporinus friderici Dourado Salminus maxillosus Saguiru Cyphocharax modestus Chimborê Schizodon nasutus Sardela Triportheus signatus Peixe cadela Galeocharax knerii and Acestrorhynchus lacustris Pintado Pseudoplatystoma coruscans Others Total Prochilodontidae Sciaenidae Pimelodidae Loricariidae Erythrinidae Callichthydae Anostomidae Anostomidae Curimatidae Anostomidae Pimelodidae a, there is also another species that receives the same popular name and occurred in small abundance (Silvano, 1997); b, Total weight caught in kg by gillnets; c, Percent contribution to total weigth in %. Table II - Temporal variability on fish catches composition at Piracicaba River basin. The numbers refers to the percentage of each fish species contributes to total weight. Popular name Corimbatâ Corvina Mandi Cascudo Lambari Traira Caborja Piranha Piava Piapara Dourado Saguiru Chimborê Sardela Peixe cadela Pintado Scientific name Prochilodus lineatus Plagioscion squamosissimus mainly Pimelodus maculatus mainly Hypostomus spp Astyanax spp and Moenkhausia spp Hoplias malabaricus Callichthys callichthys Serrasalmus spilopleura Leporinus spp Leporinus friderici Salminus maxillosus Cyphocharax spp Schizodon nasutus Triportheus spp Galeocharax spp and Acestrorhynchus spp Pseudoplatystoma coruscans 1985 E 86 a b ^ b ' b T E 94 e a, Includes all Barra Bonita's reservoir, also formed by the River Tietê (Eysink, 1995). b, Includes all Barra Bonita's reservoir, also formed by the River Tietê (Torloni et al, 1993). c, Only the fish landed at Ponte de Santa Maria da Serra, on the impounded Piracicaba River's downstream portion (Braga, 1995). OBD 5 -day was mostly untreated domestic sewage (CETESB, 1996). This pollution can create an eutrophization, reducing the oxygen levels (Prochnow, 1981). According to Jureidini et al. (1983), the Barra Bonita reservoir is an eutrophic environment. From 1984 to 1986, the mean oxygen level in the portion of Barra Bonita reservoir corresponding to the River Piracicaba was 8.2 mg-1 (Eysink, 1995). In 1995, the mean oxygen level for this same region was 5.68 mg-1 (CETESB, 1996), a reduction of 31% during the past 11 years. A reduction in the oxygen available in the water creates an unfavourable environment for most fish

5 530 R. A. M. SILVANO, A. BEGOSSI species and could change fish community composition and diversity (Welcomme, 1985; Haslam, 1990). An experimental gillnet fishery in the Barra Bonita reservoir, during 1992 and 1993, showed that the Lambaris (Astyanax bimaculatus, A. schubarti, A. fasciatus, and Moenkhausia intermedia) comprised together 7.8% of the total biomass caught (Castro, 1997). This value corresponds closely to the participation of the Lambaris in the fishery during 1994 and 1995 (9.6%, Table I). In 1985 and 1986 the biomass of Lambaris landed was much greater, comprising 32.6% of the total catch (Table II). This can be related to a reduction in the Lambaris availability to the fishermen. The Lambari fishery consists in a specialized fishery, because Lambaris are only caught with gillnets having 3 cm stretched mesh and do not capture other commercial fishes. During 1994 and 1995 only about two of 25 fishermen fished for Lambaris frequently, even though these fishes were well accepted in the market (Silvano, 1997). In 1993 and 1994 the quantity of Lambaris in the fishery increased to 16.3% (Table II), but this was probably because Braga (1995) sampled a small number of fishers, which were more prone to Lambaris fishing. Jureidini et al. (1983) observed a positive relationship between the abundance of microcrustacea (Cladocera) and the water quality in the Barra Bonita reservoir. These microcrustacea were consumed by the Moenkhausia intermedia Eigenmann (Costa & Braga, 1993), a common Lambari species in the River Piracicaba fishery. So, the reduction in its abundance in the fish landings could be a result, at least in part, from a reduced food availability caused by river pollution. The River Piracicaba possessed, during 1995, a mean mercury content in the water of mg-l (CETESB, 1996). The methyl-mercury in the water suffers a bioaccumulative process through the alimentary chain, being most concentrated in top predators as piscivorous fish species, as observed in the Madeira River (Malm et ai, 1990) and Barra Bonita reservoir (Eysink, 1995). In 1985 and 1986, the mean mercury concentration observed in the meat of carnivorous fish QGaleocbarax knerii, Hoplias malabaricus, Acestrorhynchus lacustris, Acestrorhynchus sp., Serrasalmus spilopleurä) from the Barra Bonita reservoir was 0.71 ug-g, and 55 % of the samples surpassed the limit for human consumption of 0.5 pg-g (Eysink, 1995). Large biomass of piscivorous Corvina are actually caught and consumed at the Piracicaba River region (Table I) and nothing is know about it's mercury content. Clearance of riparian forests The Piracicaba River basin had 57% of its area converted in pasture and agriculture land (CETESB, 1996). The Barra Bonita reservoir has 14.7% of its area covered by secondary forests and 13.6% covered by forestation practices (Eysink, 1995). Clearance of riparian forests usually causes deleterious consequences to fish populations and fisheries, by reducing the forestry resources availability (Lowe-McConnell, 1984; Barrela et ai, 1994). Some fishes caught at the River Piracicaba, like the Lambari Astyanax bimaculatus (Linnaeus) and Piava Leporinus spp., are omnivorous and rely at least partially on forest foods (Romanini, 1989; Costa & Braga, 1993). These species reduced in the fishery, when compared with 11 years ago (Tables I - II), indicates a reduction in their populations. This could be a collateral effect of the deforestation on the fishery, through a reduction in the offering of omnivorous fish food from riparian forests. The vegetation can also furnish refuges to native fish species, protecting them from prédation by introduced fish (Chaprnam & Chapmam, 1996) and from unexpected flooding (Pearsons & Li, 1992). Clearance of riparian forests in southwestern Brazilian rivers caused a decline in the Brycon lundii fishery at Mogi- River Guaçu (Godoy, 1975) and extinction of the River Jacaré-Pepira fishes that eat fruits (Barrela et al., 1994). Removal of marginal vegetation cover in temperate streams of North America affected their fish communities, leading to alterations in food habits (Garman & Moring, 1993) and to reductions in the species diversity (Pearsons & Li, 1992). CONCLUSION Fish landings in the River Piracicaba fishery suffered changes on its composition in the past 11 years. The environmental alterations that had occurred in the Piracicaba River basin, impoundment, pollution, and deforestation, can be important factors influencing such changes. Specific studies are needed to analyse the association of changes in fish composition and these modifications. These studies can be helpful to local environmental management. If alterations continues, the River Piracicaba fishery future could be seriously threatened. REFERENCES Agostinho A. A., Vazzoler A. E. A. M., Thomaz S. M, The high river Paraná basin: limnological and ichthyological aspects. In: J. G. Tundisi, C. E. M. Bicudo & M. Matsumura-Tundisi (eds), Limnology in Brazil. ABC/SBL, Rio de Janeiro, pp Barrela W., Beaumord A. C, Petrere Jr. M., Comparision between the fish communities of Manso River (MT) and Jacare Pepira River (SP), Brazil. Acta Biol. Venez., 15: Barthem R. B., Ribeiro M. C. L. B., Petrere Jr. M., Life strategies of some long-distance migratory catfish in relation to hydroelectric dams in the Amazon Basin. Biol. Cons., 55: Baxter R. M., Environmental effects of dams and impoundments. Ann. Rev. Ecol. Syst., 8: Bayley P. B., Petrere Jr. M., Amazon fisheries: assessment methods, current status and management options. Can. spec, Publ. Fish, aquatic Sci., Beamesderfer R. C. P., Rien T. A., Nigro A. A., Differences in the dynamics and potential production of impounded and unimpounded white sturgeon populations in the lower Columbia river. Trans. Am. Fish. Soc., 124: Böhlke J. E., Weitzman S. H., Menezes N. A., Estado atual

6 ARTISANAL FISHERY OF THE RIVER PIRACICABA. 531 da sistemática dos peixes de água doce da América do Sul. Acta Amazonica, Braga F. M. S., Biologia e Pesca da Corvina Plaigioscion squamosissimus (Teleostei, Sciaenidae) na Represa de Barra Bonita, Rio Piracicaba (SP). Phd Thesis in Zoology, UNESP, Rio Claro, Brazil, 128 pp. CBH-PCJ, Relatório de Situação dos Recursos Hídricos Tech. Rep., 65 p. CETESB, Relatório de qualidade das aguas interiores do Estado de Säo PauIo Tech. Rep., 286 pp. Castro A. C. L, Aspectos ecologicos da comunidade ictiofaunística do reservatório de Barra Bonita, SP. Rev. Brasil. Biol., Chapman L. J., Chapman C. A., Wetland ecotones as refugia for endangered fishes. Biol. Cons., 78: Costa F. E., Braga F. M. S., Estudo da alimentação natural de Astyanax bimaculalus, Astyanax schubarti e Moenkhausia intermedia (, Tetragonopterinae) na represa de Barra Bonita, rio Piracicaba (SP). Rev.UNIMAR, 15: Eysink G. G. J., Subsídios para o manejo de ecossistemas aquâticos contaminados por mercúrio. M. S. Thesis, USP, São Paulo, Brazil. 177 pp. Fink W. L., Fink S. V., Central Amazonia an its fishes. Comp. Biochem. Physiol., Fugi R., Hahn N. S., Agostinho A. A., Feeding styles of five species of bottom-feeding fishes of the High Paraná River. Environ. Biol. Fish., Garman G. C, Moring J. R., Diet and annual production of two boreal river fishes following clearcut logging. Environ. Biol. Fish, Godoy M. P., Peixes do Brasil: SubOrdem Characoidei - Bacia do Rio Mogi - Guassu. Vols I a IV, Ed. Franciscana, Piracicaba (SP), 847 pp. Haslam S. M., River Pollution: An ecological perspective. Belhaven Press, London, 253 pp. Jureidini P., Chinez S. J., Agudo E. G., Medições da produçào primária em três reservatórios do Estado de São Paulo. Ciência e Cultura, 35: Junk W. J., Robertson B. A., Darwich A. J., Vieira I., Investigações limnológicas e ictiológicas em Curuá-Una, a primeira represa hidrelétrica na Amazônia Central. Acta Amazonica, 11: Lowe-McConnell R. H., The status of studies of South American freshwater food fishes. In: T. M Zaret (ed.), Evolutionary ecology of neotropical freshwater fishes. W. Junk Publishers, The Hague, Netherlands, pp Lowe-McConnell R. H., Ecological studies in tropical fish communties. Cambridge University Press, Cambridge, N. Y., 381 pp. Malm O., Pfeiffer W. C, Souza C. M. M., Reuther R., Mercury pollution due to gold mining in the Madeira river basin, Brazil. Ambio, Parma-de-Croux M. J., Tolerancia respiratoria de Prochilodus lineatus (Pisces, Curimatidae) a condiciones crïticas de oxigeno. Iheringia, Sér. Zool., 74: Pearsons T. N., Li H. W Influence of habitat complexity on resistance to flooding and resilience of stream fish assemblages. Trans. Am. Fish Soc, 121: Petrere Jr. M., Pesca e esforço de pesca no Estado do Amazonas. II- Locais, aparelhos de captura e estatísticas de desembarque. Acta Amazonica, 8 (Suppl. 2): 54 pp. Petrere Jr. M., Fisheries in large tropical reservoirs in South America. Lakes & Reservoirs: Res. Manage., 2: Prochnow M. C. R., A qualidade das aguas na bacia do Rio Piracicaba. M. S. Thesis, UNESP, Rio Clara, Brazil, 167 pp. Rantin F. T., Glass M. L., Kalinin A. L., Verzola R. M. N., Fernandes M. N., Cardio-respiratory responses in two ecologically distinct erythrinids (Hoplias malabaricus and H. lacerdae) exposed to graded environmental hypoxia. Environ. Biol. Fish., 36: Ribeiro M. C. L. B., Petrere Jr. M., Juras A. A., Ecological integrity and fisheries ecology of the Araguaia-Tocantins River Basin, Brazil. Regulated Rivers: Res. Manag., Romanini P. U., Distribuiçào e ecologia alimentar de peixes no reservatôrio de Americana, São Paulo. M. S. Thesis, USP, Sào Paulo, Brazil. 250 pp. Santos G. M., Impactos da hidrelétrica Samuel sobre as comunidades de peixes do rio Jamari (Rondônia, Brasil). Acta Amazonica, 25: Silvano R. A. M., Ecologia de três comunidades de Pescadores no rio Piracicaba (SP). M. S. Thesis, UNICAMP, Campinas, Brazil. 147 pp. Torloni C. E. C, Corrêa A. R. A., Carvalho A. A. C, Santos J. J., Gonçalves J. L, Gereto E. J., Cruz J. A., Moreira J. A., Silva D. C, Deus E. F., Ferreira A. S., Produção pesqueira e composição das capturas emreservatórios sob concessão da CESP nos rios Tietê, Paraná e Grande no período de 1986 a Série Produçào Pesqueira, 001. CESP, Sào Paulo, 73 pp. Welcomme R. L., River fisheries. Fao Fisheries Technical Paper. Food and Agriculture Organization of the United Nations, Rome, Italy, 330 pp.