Revista de Biología Tropical ISSN: 0034-7744 [email protected] Universidad de Costa Rica Costa Rica Sampaio Franco, Ana Clara; Shimada Brotto, Daniel; Man Wai Zee, David; Neves dos Santos, Luciano Long-term (2002-2011) changes on Cetengraulis edentulus (Clupeiformes: Engraulidae) fisheries in Guanabara Bay, Brazil Revista de Biología Tropical, vol. 62, núm. 3, septiembre, 2014, pp. 1019-1029 Universidad de Costa Rica San Pedro de Montes de Oca, Costa Rica Available in: http://www.redalyc.org/articulo.oa?id=44932441018 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Long-term (2002-2011) changes on Cetengraulis edentulus (Clupeiformes: Engraulidae) fisheries in Guanabara Bay, Brazil Ana Clara Sampaio Franco1, Daniel Shimada Brotto2, David Man Wai Zee3 & Luciano Neves dos Santos1* 1. UNIRIO - Universidade Federal do Estado do Rio de Janeiro, Programa de Pós-graduação em Biodiversidade Neotropical. Avenida Pasteur, 458 sala 314A, 22290-240, Rio de Janeiro, Brasil; [email protected], [email protected] 2. UVA – Universidade Veiga de Almeida, Departamento de Ciências da Saúde. Rua Ibituruna, 108, 20271-901, Rio de Janeiro, Brasil; [email protected] 3. UERJ – Universidade do Estado do Rio de Janeiro, Departamento de Oceanografia Física. Rua São Francisco Xavier 524, sala 4025-E, 20020-100, Rio de Janeiro, Brasil; [email protected] * Correspondence Received 22-XI-2014. Corrected 30-IV-2014. Accepted 28-V-2014. Abstract: C. edentulus accounts for the major fishery resource in Guanabara Bay, but there are only few studies about its captures.This study analyzed the long term changes on C. edentulus catches in Guanabara Bay, focusing especially on temporal variation on capture effort, boat storage temperature, and fish price and size.We assessed the 2002-2011 database of fish landings at the pier of Rubi S.A., with records of year, month, total catch (kg), number of fish per kg, boat storage temperature (oC), and price per kg to boat owner (US$). Those variables differed among years and months (ANOVA; p<0.01) with strong yearXmonth interactions for all, probably related to C. edentulus reproductive and recruitment seasons and environmental conditions of Guanabara Bay. Generalized additive models revealed that high C. edentulus catches were associated with few boat loadings of large-sized fishes, which were conserved in higher boat storage temperatures and attained high market prices. Our long-term study stressed that variations on C. edentulus fishery were related to changes on boat storage temperature, fish size, price paid per kg, and frequency of landings, and that these descriptors are correlated with C. edentulus ecological traits and high phytoplankton availability. Nevertheless, further studies should be performed to address whether less evident factors, such as the fluctuation of concurrent Sardinella brasiliensis stock, would explain the temporal dynamics of C. edentulus stocks in Guanabara Bay. Rev. Biol. Trop. 62 (3): 1019-1029. Epub 2014 September 01. Key words: estuary, long-term, fisheries, landings, Cetengraulis edentulus. Engraulid fishes, commonly known as (Silva, Araújo, Azevedo, & Mendonça, 2003). anchovies, are widely distributed in tropical Adults perform seasonal migrations between and sub-tropical waters (Mcgowan & Berry, estuarine and oceanic areas (MacGregor & 1983). Anchovies are recognized as an impor- Houde, 1996), aggregating in large shoals tant trophic link in coastal food chains, since frequently targeted by commercial fisheries. they convert planktonic biomass into forage Many species of anchovies are economically for higher level consumers (Hildebrand, 1963). Most engraulids spawn at coastal areas in important in several regions in South America, the inner continental shelf, and recruitment namely Engraulis ringens in Peru, Engrau- occurs often in protected, shallow areas that lis anchoita in Argentina, and Cetengraulis provide food and shelter against predators edentulus in Venezuela (Whitehead, 1977) and Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 62 (3): 1019-1029, September 2014 1019 Guanabara Bay, Brazil (Jablonski, Azevedo, al., 2006). While economically important, the & Moreira, 2006). dynamics of C. edentulus catches in Guanabara The Atlantic anchoveta C. edentulus Bay is barely known, especially in relation to (Cuvier) is an engraulid fish, widely distrib- interannual population trends and seasonal uted throughout the Southwest Atlantic, occur- fluctuations on its capture. In this sense, this ring from Antilles and Cuba to Southern Brazil study aims to analyze the long term changes on (Whitehead, Nelson, & Wongratana, 1988). C. edentulus catches in Guanabara Bay, focus- C. edentulus first matures at 118mm total ing especially on temporal variation on capture length (L50 for both sexes), reaching 200mm effort, boat storage temperature, and fish price at maximum (Silva et al., 2003; Souza-Con- and size between 2002 and 2011. ceição, Rodrigues-Ribeiro, & Castro-Silva, 2005). This species feeds mainly on phyto- MATERIALS AND METHODS plankton and is widely tolerant to changes in environmental conditions (Krumme, Keuthen, Guanabara Bay is an estuary around Barletta, Saint-Paul, & Villwock, 2008; Giar- 400km2 located on the coast of Rio de Janeiro rizzo & Krumme, 2009).It is often associ- state (22°50’ S - 43°10’ W; Fig. 1). The ated with muddy substrates of inner bay zones, where salinity is low, temperatures are high, and phytoplankton biomass is high due to the great input of organic waste (Sergipense, Caramaschi, & Sazima, 1999; Gay, Sergipense, Brazil & Rocha, 2000; Silva et al., 2003; Souza- Conceição et al., 2005; Araújo, Silva, Santos, & Vasconcellos, 2008). C. edentulus began to be used as human 21ºS food and fish meal since early 1980s, in part due to declining stocks of other traditionally Río de Janeiro exploited species, such as Sardinella brasil- 22ºS iensis (Whitehead et al., 1988; Jablonski et al., 44ºW 42ºW 2006), currently accounting for the major fish- ery resource in coastal bays of Rio de Janeiro, Magé Duque Southeastern Brazil (Araújo et al., 2008). Over- de Caxias I. de all, commercial vessels operating at Guanabara Paqueta Bay use purse seines (35-40m length; 12mm mesh) to catch preferentially C. edentulus but I. do São Gonçalo also other small pelagic fish species (i.e. S. Governador brasiliensis) within the area (Vianna, 2009). Fish are captured near the surface, often togeth- Landing site er with a few benthic species, because of the shallow waters where those fishing operations are performed. Niterói C. edentulus is the dominant exploited species in Guanabara Bay (12 427t in 2004), Rio de Janeiro accounting for 69% of total fish produc- tion. Despite its low value per kilogram, the significant bulk of Atlantic anchoveta land- Fig. 1. Geographic location of Guanabara Bay, Rio de ings in Guanabara Bay provided more than Janeiro, Brazil, showing the landing site of C. edentulus US$1 million for local trade (Jablonski et captures by purse seine fishery. 1020 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN-0034-7744) Vol. 62 (3): 1019-1029, September 2014 climate is tropical-humid with a warm-rainy the predictor. The model complexity of GAMs season (December-March) and a cold-dry sea- was chosen by the stepwise selection procedure son (July-August) (Paranhos & Mayr, 1993; using the Akaike information criterion (AIC). Valentin et al., 1999). Guanabara Bay is 36km AIC considers not only the goodness of fit but long and has 3x109m3 of water volume, mean also parsimony, penalizing more complex mod- depth of 7.6m, and maximum depth of 30m at els (Burnham & Anderson, 1998). the entrance channel (Valentin et al., 1999). Tidal currents account for most water circula- RESULTS tion in this bay, with a micro tidal regime (i.e., 0.7m of amplitude), semi-diurnal tides, and The catches of C. edentulus varied sig- maximum currents of 1.6m/s that result in 23 nificantly among years (F7, 7 866=80.9, p<0.01) days of water residence time (Kjerfve, Ribeiro, and months (F10, 7 866=4.2, p<0.01), with a Dias, Filippo, & Quaresma, 1997). Substrate strong year × month interaction (F87, 7 866=11.2, is predominantly muddy, with increasingly p<0.01). Overall, the catches increased pro- contribution of sand toward the outer zone, and gressively through years, with low yields being the salinity ranges from 21.0 to 34.5 (Kjerfve et recorded in 2002-2003, intermediate values al., 1997). Guanabara Bay is surrounded by one within the 2004-2009 period, and greater catch- of the largest metropolitan areas in Brazil (i.e. es at 2010-2011 (Tukey test, p<0.05 for all, Rio de Janeiro city), with more than 11 million Fig. 2). High C. edentulus yields were found in inhabitants. As consequence, the water quality May-June whereas low values were recorded is poorer at the inner zone, because of the main during February and September-November land proximity and the restrict circulation, (Tukey test, p<0.05 for all), a trend that was while better conditions (i.e. higher transpar- not clearly observed for any year separately. ency and dissolved oxygen) are found toward The amount of C. edentulus per kg dif- the outer zone, more influenced by adjacent fered significantly with years (F7, 7 866=2 947.3, oceanic waters. p<0.01) and months (F10, 7 866=187.6, p<0.01), The statistical data examined proceed from with a significant year × month interaction a period of ten years of fish landings at the (F87, 7 866=56.7, p<0.01). Higher numbers of pier of Rubi S.A., a fish processing industry C. edentulus per kg were recorded during located near Guanabara Bay at Rio de Janeiro 2003-2004, indicating a greater contribution of state. Fish was caught by boats that operate relatively small-sized individuals in the catches with purse seines in the region from Janu- (Tukey test, p<0.05 for all, Fig.