18 research outputs found

    Artisanal fisheries production in the coastal zone of Itaipu, Niterói , RJ, Brazil

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    As pescarias artesanais na zona costeira de Itaipu-RJ desempenham um papel importante no mercado local, mas pouco se conhece sobre a produção e a produtividade da pesca. De abril-2001 a março-2003, nós monitoramos um total de 618 desembarques das pescarias de arrastos-de-praia (99), de redes de emalhe (corvineira - 331, linguadeira - 40 e rede alta - 25), de linha-e-anzol (98), de zangareio (17), e de arpão e puçá (cinco e três respectivamente). A produção monitorada total foi de 21866 kg e a captura por unidade de esforço (CPUE) de 35,4 kg.viagem-1. Considerando o número de dias efetivos de pesca e a produção média diária por arte de pesca, a produção anual foi estimada em 136687 kg (0.2% da produção do estado em 2004). Os recursos predominantes foram: Micropogonias furnieri,Trichiurus lepturus, lulas (Loligo spp.), peixes clupeiformes (Sardinella brasiliensis,Cetengraulis edentulus,Pellona harrowerii e Harengula clupeola ), Eucinostomus spp., Cynoscion spp., Menticirrhus spp., Caranx crysos e Selene setapinnis. A análise combinada utilizando métodos de classificação hierárquica e não-hierárquica separou quatro grupos de artes de pesca e cinco de espécies, baseada nos seus padrões de similaridade, identificando as artes de pesca que melhor capturam os diferentes grupos de recursos pesqueiros. O arrasto-de-praia foi a arte de pesca menos seletiva e mais produtiva no verão. A corvineira foi a segunda pescaria mais produtiva com rendimentos maiores no verão e outono. As capturas com linguadeira incluíram raias e Paralychthys spp., enquanto que a rede alta capturou principalmente M. furnieri,Mugil spp. e tubarões.Artisanal fisheries in the coastal zone of Itaipu-RJ play an important role in the local market, but little is known about production and productivity of the fisheries. From April 2001 to March 2003, we monitored a total of 618 landings from the beach-seine (99), the gill nets ("corvineira" - 331, "linguadeira" - 40 and "rede alta" - 25), the hook and line (98), the squid jigging (17), and the spear fishing and trap fisheries (five and three, respectively). The total monitored production was 21866 kg and the catch per unit effort (CPUE) 35.4 kg.trip-1. Considering the number of effective fishing days and the average daily production per fishing gear, the annual production was estimated at 136687 kg (0.2% of the state's production in 2004). Predominant resources were: Micropogonias furnieri,Trichiurus lepturus, squids (Loligo spp.), clupeiform fishes (Sardinella brasiliensis, Cetengraulis edentulus, Pellona harrowerii and Harengula clupeola), Eucinostomus spp., Cynoscion spp., Menticirrhus spp., Caranx crysos and Selene setapinnis. The combined analysis using hierarchical and non-hierarchical classification methods, separated four fishing gears and five species groups, based on their similarity patterns, identifying gears that most effectively capture the different fish groups. The beach-seine was less selective and most productive fishery in the summer. The "corvineira" was the second most productive fishery with higher yields in the summer and fall. Catches of "linguadeira" included rays and Paralychthys spp., wherereas the "rede alta" caught primarily M. furnieri,Mugil spp. and sharks

    Length-based estimates of growth parameters and mortality rates of fish populations from a coastal zone in the Southeastern Brazil

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    ABSTRACT Small-scale fisheries in Brazil contribute to a significant share of total fish production, accessing a large variety of species. Life history parameters from these resources are important for their management and conservation, based on primary data. The objective of this article is to generate growth parameters and mortality rates of ten fish populations from a coastal zone in Southeastern Brazil. Monthly samples were taken between January 2011 and November 2014 from landings of the beach-seine fishery in an area adjacent to the entrance of the Guanabara Bay. All fishes were measured (total length) and weighed. The length-weight relationships (LWR) were estimated by linear regression analysis on log-transformed data of the equation: W = aL b . The Von Bertalanffy Growth Function (VBGF) was fitted to size-at-age data to obtain growth parameters (K, L ∞ ). The length-converted catch curve was used for estimating the instantaneous total mortality (Z). Taylor’s equations provided an independent estimate of the natural mortality (M) and longevity. The difference between Z and M derived Fishing mortality (F). A total of 2,938 individuals from ten fish species were used to determine the length-weight relationships. Harengula clupeola (Cuvier, 1829) has a new maximum length record for the FishBase LWR database. Sardinella brasiliensis (Steindachner, 1879) presented the smallest and largest size recorded for LWR observed in the literature and FishBase database. Upeneus parvus showed the greatest total length, while Trichiurus lepturus Linnaeus, 1758, Orthopristis ruber (Cuvier, 1830) and Dactylopterus volitans (Linnaeus, 1758) presented the smallest sizes for LWR in FishBase. The other species showed parameters within the expected values for each group. The performance index combining information from K and L ∞ presented values between 2.32 and 3.76 and were considered appropriate for the populations evaluated. Fishing was the primary source of mortality for Caranx crysos (Mitchill, 1815), Eucinostomus argenteus Baird & Girard, 1855, S. brasiliensis and U. parvus, and less important for Cynoscion jamaicensis (Vaillant & Bocourt, 1883), D. volitans, O. ruber, Selene setapinnis (Mitchill, 1815), T. lepturus and H. clupeola. The parameters generated may be used for the management and conservation of the species’ stocks

    Artisanal fisheries production in the coastal zone of Itaipu, Niterói , RJ, Brazil

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    Artisanal fisheries in the coastal zone of Itaipu-RJ play an important role in the local market, but little is known about production and productivity of the fisheries. From April 2001 to March 2003, we monitored a total of 618 landings from the beach-seine (99), the gill nets ("corvineira" - 331, "linguadeira" - 40 and "rede alta" - 25), the hook and line (98), the squid jigging (17), and the spear fishing and trap fisheries (five and three, respectively). The total monitored production was 21866 kg and the catch per unit effort (CPUE) 35.4 kg.trip-1. Considering the number of effective fishing days and the average daily production per fishing gear, the annual production was estimated at 136687 kg (0.2% of the state's production in 2004). Predominant resources were: Micropogonias furnieri,Trichiurus lepturus, squids (Loligo spp.), clupeiform fishes (Sardinella brasiliensis, Cetengraulis edentulus, Pellona harrowerii and Harengula clupeola), Eucinostomus spp., Cynoscion spp., Menticirrhus spp., Caranx crysos and Selene setapinnis. The combined analysis using hierarchical and non-hierarchical classification methods, separated four fishing gears and five species groups, based on their similarity patterns, identifying gears that most effectively capture the different fish groups. The beach-seine was less selective and most productive fishery in the summer. The "corvineira" was the second most productive fishery with higher yields in the summer and fall. Catches of "linguadeira" included rays and Paralychthys spp., wherereas the "rede alta" caught primarily M. furnieri,Mugil spp. and sharks

    Conversion factor for size structure reconstruction and growth of Lophius gastrophysus Miranda Ribeiro, 1915 catches in the South Atlantic Ocean

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    Lophius gastrophysus is an exploited deep-sea demersal fishing resource in the Southeast-South region of Brazil, a capture target for the twin trawl multi-specific bottom trawling fleet. Considered a prized fish, it is commonly processed on board, retaining commercial cuts of the tail called colas. Thus it is difficult to recognize the original length of the specimens and, consequently, to assess the dynamics of sources and the impacts of catches. Individual length and weight data were used to generate body predictive models correlated to the monkfish cola. The parameters of growth, mortality and exploitation rate were also estimated from the size structure of Lophius gastrophysus captured by the industrial bottom trawling fleet in Southeast Brazil between May 2013 and April 2015, assessing monkfish stock based on indirect estimates of life history information. All predictive models of body size showed coefficients of determination above 0.9 (P <0.001), indicating good data adjustments. The growth parameters were determined by the minimum residual variance methodology, being: L∞ = 92.4 cm and k = 0.158/year. The size structure tended to increase with depth in the spring. Individuals under the age of sexual maturity contributed significantly to catches. The length of first sexual maturation was estimated at 48.6 cm and the recruitment age was between 6 and 7 years. The coefficients of total, natural, fishing and exploitation rates were estimated at: Z = 0.676; M = 0.241; F = 0.436 and E = 0.644. The fishing mortality rate was higher than the reference value (E > 0.50) indicating a state of overexploitation of the southeast most part of stock. A review of the current Brazilian legislation established for the species on the southeast coast is recommended

    DNA barcoding reveals deep divergent molecular units in Pomatomus saltatrix (Perciformes: Pomatomidae): implications for management and global conservation

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    Pomatomus saltatrix is a high-value marine pelagic coastal fish, that is fished throughout subtropical and temperate coastal waters around the world. Despite its large economic potential, there are no global data on its genetic diversity, which could compromise the conservation of the species. The aim of this study was to analyse the genetic-evolutionary structuring of the species, with the intention of evaluating different genetic P. saltatrix stocks that may indicate potential species. Based on 157 Cytochrome C Oxidase Subunit 1 sequences, the molecular delimitation analyses of species (distance and coalescence methods), as well as the haplotype network, found profound geographic structuring related to five distinct units with high and significant FST pairwise values. The divergence of these molecular units is mostly related to the Pleistocene glacial and interglacial cycles of climatic oscillations. It is hypothesized that one ancestral lineage, adapted to cold water environments, diversified into two lineages, with one more adapted to warmer environments. The high values of global genetic diversity (π = 0.016; h = 0.96) may be related to the existing profound genetic differentiation. Due to the presence of five Molecular Operational Taxonomic Units (MOTUs) within the species it is necessary to employ different regional management strategies. Traits of low haplotype richness and shallow population contraction were identified in the MOTUs V (Venezuela and Brazil) and III (Turkey and Australia), respectively, representing conservation priorities. Other molecular markers, as well as morphological data, should be explored with the aim of defining the taxonomic status of P. saltatrix stocks.Fil: de Queiroz Brito, Maria Clara G.. Universidade Federal de Pernambuco; BrasilFil: Barros Machado, Carolina. Universidade Federal do São Carlos; BrasilFil: Gama Maia, Danielle de Jesus. Universidade Federal do Rio de Janeiro; BrasilFil: Pereira Jacobina, Uedson. Universidade Federal de Alagoas; BrasilFil: Nirchio, Mauro. Universidad de Oriente; VenezuelaFil: Rotundo, Matheus M. Universidade Santa Cecília; BrasilFil: de Almeida Tubino, Rafael. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Fernandez Iriarte, Pedro Jose. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Haimovici, Manuel. Universidade Federal do Rio Grande; BrasilFil: Torres, Rodrigo Augusto. Universidade Federal do Paraná; Brasi

    The Path towards Endangered Species: Prehistoric Fisheries in Southeastern Brazil.

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    Brazilian shellmounds are archaeological sites with a high concentration of marine faunal remains. There are more than 2000 sites along the coast of Brazil that range in age from 8,720 to 985 cal BP. Here, we studied the ichthyoarchaeological remains (i.e., cranial/postcranial bones, otoliths, and teeth, among others) at 13 shellmounds on the southern coast of the state of Rio de Janeiro, which are located in coastal landscapes, including a sandy plain with coastal lagoons, rocky islands, islets and rocky bays. We identified patterns of similarity between shellmounds based on fish diversity, the ages of the assemblages, littoral geomorphology and prehistoric fisheries. Our new radiocarbon dating, based on otolith samples, was used for fishery characterization over time. A taxonomical study of the ichthyoarchaeological remains includes a diversity of 97 marine species, representing 37% of all modern species (i.e., 265 spp.) that have been documented along the coast of Rio de Janeiro state. This high fish diversity recovered from the shellmounds is clear evidence of well-developed prehistoric fishery activity that targeted sharks, rays and finfishes in a productive area influenced by coastal marine upwelling. The presence of adult and neonate shark, especially oceanic species, is here interpreted as evidence of prehistoric fisheries capacity for exploitation and possibly overexploitation in nursery areas. Various tools and strategies were used to capture finfish in seasonal fisheries, over rocky reef bottoms and in sandy littoral environments. Massive catches of whitemouth croaker, main target dermersal species of South Atlantic coast, show evidence of a reduction in body size of approximately 28% compared with modern fisheries. Fishery activity involving vulnerable species, especially in nursery areas, could mark the beginning of fish depletion along the southeastern Brazilian coast and the collapse of natural fish populations

    Drilled shark teeth.

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    <p>(1a-b) <i>Carcharodon carcharias</i>, lower tooth, Major, MNUFRJ-ZA-146. (2a-b) <i>Carcharhinus altimus</i>, upper tooth, Acaiá, MNUFRJ-ZA-868. (3a-b) <i>Carcharhinus</i> <i>leucas</i>, upper tooth, Ilha do Cabo Frio, MNUFRJ-ZA-869. (4a-b) <i>Carcharhinus</i> <i>plumbeus</i>, upper tooth, Caieira, MNUFRJ-ZA-97. (5a-b) <i>Galeocerdo cuvier</i>, indet. position tooth, Acaiá, MNUFRJ-ZA-870. (6a-b) <i>Sphyrna mokarran</i>, upper tooth, Algodão, MNUFRJ-ZA-54. Scale bar 1 cm.</p
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