The artisanal fishing of black drum (Pogonias cromis, Sciaenidae) in estuary Lagoon of Patos, Brazil / A pesca artesanal da miragaia (Pogonias cromis, Sciaenidae) no estuário da Lagoa dos Patos, Brasil

The increasing in the abundance of non-resident fish in the estuarine area attracts the interest of the fishing fleet, which determines the fishing seasons in the same period of increasing abundance. The black drum (Pogonias cromis) is an estuarine-dependent fish, (threatened with extinction due to) overexploitation in southern Brazil. In the estuary of Patos Lagoon, the scarcity of data on the biology and fishery species (hinder) the formulation of management plans. This study aims to analyze the artisanal fisheries of the black drum in the estuary of Patos Lagoon, by analyzing CPUE changes and the different compositions of juveniles, adults, males and females landed, relating them to the period of abundance increasing in the region. The fishing effort is the main cause for variations in the abundance of black drum in the estuary of Patos Lagoon, where the largest catches occur inside and outside the breeding season. The composition of landings varies throughout the year, females and adult fish predominate during the reproductive season, during the rest of the year no significant difference between males and females was found, and juveniles are predominant in the landings. The mean age of fish also changed, with higher values in spawning period. We conclude that these fisheries would prevent the recovery of the stock.(AU)

O aumento na abundância de peixes não residentes da zona estuarina atrai o interesse da frota pesqueira, o que determina o período das safras de pesca na mesma época do aumento da abundância. No sul do Brasil a miragaia (Pogonias cromis) é um peixe estuarino-dependente, ameaçado de extinção devido a sobreexplotação. No estuário da Lagoa dos Patos, a falta de dados sobre a biologia e pesca da espécie são fatores limitantes na formulação de planos de manejo. Este trabalho tem o objetivo de analisar a pesca artesanal da miragaia no estuário da Lagoa dos Patos, discutindo as variações da CPUE e as diferentes composições de juvenis e adultos desembarcados, relacionando-as com o período de aumento da abundância na região. A pesca intensa é o principal responsável pelas variações na abundância miragaias no estuário da Lagoa dos Patos, onde as altas capturas acontecem dentro e fora do período reprodutivo. A composição dos desembarques se modifica ao longo do ano, fêmeas e peixes adultos predominam na estação reprodutiva, durante o período de repouso não há diferença significativa entre machos e fêmeas, e juvenis são predominantes, a média de idade também se modifica, com maiores valores no período de desova. Conclui-se que esta pescaria pode comprometer a recuperação do estoque.(AU)

The artisanal fishing of black drum (Pogonias cromis, Sciaenidae) in estuary Lagoon of Patos, Brazil / A pesca artesanal da miragaia (Pogonias cromis, Sciaenidae) no estuário da Lagoa dos Patos, Brasil

The increasing in the abundance of non-resident fish in the estuarine area attracts the interest of the fishing fleet, which determines the fishing seasons in the same period of increasing abundance. The black drum (Pogonias cromis) is an estuarine-dependent fish, (threatened with extinction due to) overexploitation in southern Brazil. In the estuary of Patos Lagoon, the scarcity of data on the biology and fishery species (hinder) the formulation of management plans. This study aims to analyze the artisanal fisheries of the black drum in the estuary of Patos Lagoon, by analyzing CPUE changes and the different compositions of juveniles, adults, males and females landed, relating them to the period of abundance increasing in the region. The fishing effort is the main cause for variations in the abundance of black drum in the estuary of Patos Lagoon, where the largest catches occur inside and outside the breeding season. The composition of landings varies throughout the year, females and adult fish predominate during the reproductive season, during the rest of the year no significant difference between males and females was found, and juveniles are predominant in the landings. The mean age of fish also changed, with higher values in spawning period. We conclude that these fisheries would prevent the recovery of the stock.

O aumento na abundância de peixes não residentes da zona estuarina atrai o interesse da frota pesqueira, o que determina o período das safras de pesca na mesma época do aumento da abundância. No sul do Brasil a miragaia (Pogonias cromis) é um peixe estuarino-dependente, ameaçado de extinção devido a sobreexplotação. No estuário da Lagoa dos Patos, a falta de dados sobre a biologia e pesca da espécie são fatores limitantes na formulação de planos de manejo. Este trabalho tem o objetivo de analisar a pesca artesanal da miragaia no estuário da Lagoa dos Patos, discutindo as variações da CPUE e as diferentes composições de juvenis e adultos desembarcados, relacionando-as com o período de aumento da abundância na região. A pesca intensa é o principal responsável pelas variações na abundância miragaias no estuário da Lagoa dos Patos, onde as altas capturas acontecem dentro e fora do período reprodutivo. A composição dos desembarques se modifica ao longo do ano, fêmeas e peixes adultos predominam na estação reprodutiva, durante o período de repouso não há diferença significativa entre machos e fêmeas, e juvenis são predominantes, a média de idade também se modifica, com maiores valores no período de desova. Conclui-se que esta pescaria pode comprometer a recuperação do estoque.

Pilot study about fish self-consumption among artisanal fishermen in Patos Lagoon estuary, RS, Brazil / Estudo piloto sobre o autoconsumo de pescado entre pescadores artesanais do estuário da Lagoa dos Patos, RS, Brasil

The artisanal fishery in Patos Lagoon estuary is a traditional activity. The main target species are mullet Mugil liza, white-croaker Micropogonias furnieri and pink-shrimp Farfantepenaeus paulensis. It is common for fishermen to consume the fish caught by them (self-consumption), what is believed to be important in certain communities. This study aims to estimate quantitatively and qualitatively the self-consumption of fish in three fishing communities of Rio Grande city. From September 2010 to December 2011, ten fishermen from each community were periodically interviewed for collecting information about fisheries and fish self-consumption. The mean per capita consumption of fish found was 109 g day-1, and 38.57 kg year-1. The higher mean daily self-consumption was found for spring (161 g/person) and summer (162 g/person), being the white croaker and the pink shrimp, respectively, the main consumed species. The fish is an important source of food to the artisanal fisherman of the studied communities.

A pesca artesanal no estuário da Lagoa dos Patos é uma atividade tradicional. As principais espécies-alvo são a tainha Mugil liza, a corvina Micropogonias furnieri e o camarão-rosa Farfantepenaeus paulensis. É comum que pescadores consumam parte do que capturam (autoconsumo), o que pode ser significativo em certas comunidades. Neste trabalho objetivou-se estimar quali-quantitativamente o autoconsumo de pescado em três comunidades pesqueiras do município de Rio Grande. Entre setembro de 2010 e dezembro de 2011 foram entrevistados, periodicamente, 10 pescadores de cada comunidade, coletando-se informações sobre a pescaria e a quantidade de pescado consumida. A média de consumo per capita de pescado foi de 109 g dia-1 e 38,57 kg ano-1. O autoconsumo médio diário foi maior na primavera (161 g/pessoa) e no verão (162 g/pessoa), sendo a corvina e o camarão-rosa, respectivamente, as principais espécies consumidas. Os resultados indicaram que o pescado é importante fonte de alimento para os pescadores artesanais das comunidades.

Record of the freshwater stingrays Potamotrygon brachyura and P. motoro (Chondrichthyes, Potamotrygonidae) in the lower Uruguay river, South America / Registro das raias de água doce Potamotrygon brachyura e P. motoro (Potamotrygonidae) no baixo rio Uruguai, America do Sul

Freshwater stingrays, or potamotrygonids, are restricted to Neotropical river drainages. These elasmobranchs are well adapted to freshwater environments and the number of described species gradually increases as further research is carried out. Some of the first studies on their systematics and natural history were carried out in the 1960s and 1970s in southern South America. However, there is no new published data on potamotrygonids from Uruguayan waters since then (except for local journal reports from sportive fishermen and specimens deposited in Uruguayan collections). The present study aims to record the recent occurrence of two species of potamotrygonids caught by sport fishermen, with comments on other published historical records for the same area. As many other elasmobranchs, these species have an important, but not always well understood, role in the Uruguayan rivers ecosystems.(AU)

As raias de água doce ou potamotrigonídeos estão restritas às drenagens dos rios Neotropicais. Estas raias tem se adaptado bem aos ambientes de água doce e o número de espécies descritas aumenta gradualmente conforme as pesquisas na área se intensificam. Alguns dos primeiros estudos sobre a sistemática e a historia natural deste grupo foram realizados nas décadas de 1960 e 1970 na região Sul de América do Sul. Porém, há poucos dados publicados sobre potamotrigonídeos em águas uruguaias desde então (com exceção de registros de pescadores esportivos publicados em jornais locais, e espécimes depositados em coleções uruguaias). O presente estudo, portanto, tem como objetivo registrar a ocorrência de duas espécies de potamotrigonídeos no Uruguai capturados por pescadores esportivos assim como realizar uma compilação de ocorrências anteriores presentes na literatura. Como muitos outros elasmobrânquios, estas espécies possuem um papel importante nos ecossistemas dos rios uruguaios, embora não completamente compreendido.(AU)

The reproductive biology of the plata pompano, Trachinotus marginatus (Teleostei: Carangidae), in southern Brazil

The Plata pompano, Trachinotus marginatus (Cuvier, 1832), is an endemic carangid of the Southwestern Atlantic Ocean, occurring from Rio de Janeiro to Uruguay. This study describes the reproductive period, spawning type, the size at first gonadal maturation and the length-weight relationship of individuals sampled from landings of the artisanal and commercial fishing fleets in Rio Grande that operate along the coast of Rio Grande do Sul state, southern Brazil (~ 32ºS) to the Uruguayan border (~ 34ºS). Monthly collections from September 2008 through January 2010 yielded 274 individuals ranging from 142 to 444 mm in total length (TL). The gonadal development stages were defined according to the histological examination of the ovaries and the testes. The relationship between TL (mm) and total weight TW (g) was statistically different between males (TW = 0.000463*TL2.7655) and females (TW = 0.000361*TL2.8131), showing negative allometric growth for both sexes. The sizes at first maturity were 187.2 mm and 254.9 mm for females and males, respectively. The presence of two modal groups of oocyte diameters suggested that total spawning occurred. The interpretation of the monthly variations of the condition factor and gonadosomatic index, which are associated with higher frequencies of the more advanced stages of gonadal development, identified the spring and summer months as the reproductive period, with a peak in the reproductive activity during November and January. These results suggested that the species has an opportunistic reproductive strategy.

The reproductive biology of the plata pompano, Trachinotus marginatus (Teleostei: Carangidae), in southern Brazil

The Plata pompano, Trachinotus marginatus (Cuvier, 1832), is an endemic carangid of the Southwestern Atlantic Ocean, occurring from Rio de Janeiro to Uruguay. This study describes the reproductive period, spawning type, the size at first gonadal maturation and the length-weight relationship of individuals sampled from landings of the artisanal and commercial fishing fleets in Rio Grande that operate along the coast of Rio Grande do Sul state, southern Brazil (~ 32ºS) to the Uruguayan border (~ 34ºS). Monthly collections from September 2008 through January 2010 yielded 274 individuals ranging from 142 to 444 mm in total length (TL). The gonadal development stages were defined according to the histological examination of the ovaries and the testes. The relationship between TL (mm) and total weight TW (g) was statistically different between males (TW = 0.000463*TL2.7655) and females (TW = 0.000361*TL2.8131), showing negative allometric growth for both sexes. The sizes at first maturity were 187.2 mm and 254.9 mm for females and males, respectively. The presence of two modal groups of oocyte diameters suggested that total spawning occurred. The interpretation of the monthly variations of the condition factor and gonadosomatic index, which are associated with higher frequencies of the more advanced stages of gonadal development, identified the spring and summer months as the reproductive period, with a peak in the reproductive activity during November and January. These results suggested that the species has an opportunistic reproductive strategy.

The reproductive biology of the plata pompano, Trachinotus marginatus (Teleostei: Carangidae), in southern Brazil

The Plata pompano, Trachinotus marginatus (Cuvier, 1832), is an endemic carangid of the Southwestern Atlantic Ocean, occurring from Rio de Janeiro to Uruguay. This study describes the reproductive period, spawning type, the size at first gonadal maturation and the length-weight relationship of individuals sampled from landings of the artisanal and commercial fishing fleets in Rio Grande that operate along the coast of Rio Grande do Sul state, southern Brazil (~ 32ºS) to the Uruguayan border (~ 34ºS). Monthly collections from September 2008 through January 2010 yielded 274 individuals ranging from 142 to 444 mm in total length (TL). The gonadal development stages were defined according to the histological examination of the ovaries and the testes. The relationship between TL (mm) and total weight TW (g) was statistically different between males (TW = 0.000463*TL2.7655) and females (TW = 0.000361*TL2.8131), showing negative allometric growth for both sexes. The sizes at first maturity were 187.2 mm and 254.9 mm for females and males, respectively. The presence of two modal groups of oocyte diameters suggested that total spawning occurred. The interpretation of the monthly variations of the condition factor and gonadosomatic index, which are associated with higher frequencies of the more advanced stages of gonadal development, identified the spring and summer months as the reproductive period, with a peak in the reproductive activity during November and January. These results suggested that the species has an opportunistic reproductive strategy.

Age, growth, and reproductive aspects of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil

The dusky grouper, Mycteroperca marginata, is an important commercial marine fish that is currently considered an endangered species worldwide and listed as overexploited in Brazil. Although its reproductive biology has been studied elsewhere, no information is available for populations in its southernmost distribution limit on the Brazilian coast. The present work investigates age structure, growth and reproduction of individuals inhabiting a pair of rocky jetties, about 4.5 km long each, located in the mouth of Patos Lagoon in the municipality of Rio Grande, in the southwestern Atlantic Ocean. A total of 130 individuals obtained between February 2007 and May 2009 were analyzed, with total length ranging from 260 to 800 mm. The growth coefficient found in the present study (K: 0.069) was lower than values reported for dusky grouper populations from the Mediterranean Sea (0.087) and southeast Africa (0.09). This difference could be related to higher average water temperatures in these regions compared to the current study site or due to poorer habitat quality in terms of the shelters available for dusky grouper individuals to establish their territories. Microscopic ovarian analyses of individuals during three years of sampling revealed only the occurrence of immature and resting females. The absence of ripe or post-spawning individuals, associated with low GSI values (<0.2) over the studied months, indicates that the dusky grouper did not use this man-made rocky substrate as a spawning site. The current L50 estimate of 451.3 mm indicates that most individuals captured in this area are immature. Such fishing pressure on immature specimens, associated with its slow growth rates and complex reproductive characteristics, threatens sustainability of the current dusky grouper fishery at the study site.(AU)

A garoupa-verdadeira, Mycteroperca marginata, é uma espécie de importância comercial que atualmente é considerada como ameaçada mundialmente e sobre-explotada no Brasil. Embora sua biologia reprodutiva tenha sido estudada em outras regiões, nenhuma informação está disponível sobre populações que habitam o extremo sul da sua distribuição na costa brasileira. O presente trabalho investiga a estrutura de idade, crescimento e reprodução de indivíduos que habitam dois molhes de pedra, com cerca de 4,5 km de extensão cada, localizados na desembocadura da laguna dos Patos no município de Rio Grande, no Atlântico Sudoeste. Foram analisados 130 indivíduos obtidos entre fevereiro de 2007 e maio de 2009, com comprimento total entre 260 e 800 mm. O coeficiente de crescimento no presente estudo (K: 0,069) foi inferior aos valores reportados para oMediterrâneo (0,087) e sudeste da África (0,09). Essa diferença pode estar relacionada a temperaturas médias maiores nessas regiões comparadas ao presente local de estudo ou devido a menor qualidade de habitat em termo de abrigos para os indivíduos de garoupa-verdadeira estabelecerem seus territórios. Análises microscópicas dos ovários dos indivíduos durante esses três anos de amostragens revelaram somente a ocorrência de indivíduos imaturos e fêmeas em repouso. A ausência de indivíduos ovados ou em pós-desova, associada com baixos valores do IGS (<0,2), ao longo de todos os meses de coleta, indica que a garoupa-verdadeira não utiliza esse substrato rochoso construído pelo homem como um local de desova. A estimativa de um L50 de 451,3 mm indica que a maioria dos indivíduos capturados nessa região é imatura. Pressão de pesca sobre indivíduos imaturos, associada com a sua lenta taxa de crescimento e complexo modo reprodutivo, ameaça a sustentabilidade da atual pesca da garoupa-verdadeira na área de estudo.(AU)

Determination and historical analysis of the common Argentinean hake, Merllucius hubbsi Marini, 1933 (Teleostei, Gadiformes), juvenilesconcentration areas in the Argentinean-Uruguayan common fishing zone, between autumn 1986 and winter 1991 / Determinación y análisis histórico de las áreas de concentración de juveniles de merluza, Merluccius hubbsi Marini, 1933 (Teleostei, Gadiformes), en la zona común de pesca argentino-uruguaya, entre el otoño de 1986 y el invierno de 1991

Seven surveys for the assessment of the state of the stock of the Argentine hake (Merluccius hubbsi) covering the Argentinean-Uruguayan Common Fishing Zone were analyzed in order to establish the areas of higher juveniles concentrations. For all the cruises, the juveniles concentration areas were found between depths of 50 and 200 m and latitudes 34°18S and 37°20S. The protection of this part of the hakes population is discussed as a precautory measure for the exploitation of this resource by Uruguay and Argentina.

Foram analisadas sete campanhas de prospecção para avaliação do estado do recurso merluza (Merluccius hubbsi) realizadas na Zona Comum de Pesca Argentino-Uruguaia entre 1986 e 1991 para determinar as áreas de maior concentração de juvenis. Para todas as campanhas foram detectadas zonas de alta concentração de juvenis entre 50 e 200 m de profundidade e entre as latitudes de 34°18S e 37°20S. Discute-se sobre a proteção desta parte da população como medida preventiva na exploração do recurso por parte do Uruguai e da Argentina.

Pilot study about fish self-consumption among artisanal fishermen in Patos Lagoon estuary, RS, Brazil / Estudo piloto sobre o autoconsumo de pescado entre pescadores artesanais do estuário da Lagoa dos Patos, RS, Brasil

The artisanal fishery in Patos Lagoon estuary is a traditional activity. The main target species are mullet Mugil liza, white-croaker Micropogonias furnieri and pink-shrimp Farfantepenaeus paulensis. It is common for fishermen to consume the fish caught by them (self-consumption), what is believed to be important in certain communities. This study aims to estimate quantitatively and qualitatively the self-consumption of fish in three fishing communities of Rio Grande city. From September 2010 to December 2011, ten fishermen from each community were periodically interviewed for collecting information about fisheries and fish self-consumption. The mean per capita consumption of fish found was 109 g day-1, and 38.57 kg year-1. The higher mean daily self-consumption was found for spring (161 g/person) and summer (162 g/person), being the white croaker and the pink shrimp, respectively, the main consumed species. The fish is an important source of food to the artisanal fisherman of the studied communities.

A pesca artesanal no estuário da Lagoa dos Patos é uma atividade tradicional. As principais espécies-alvo são a tainha Mugil liza, a corvina Micropogonias furnieri e o camarão-rosa Farfantepenaeus paulensis. É comum que pescadores consumam parte do que capturam (autoconsumo), o que pode ser significativo em certas comunidades. Neste trabalho objetivou-se estimar quali-quantitativamente o autoconsumo de pescado em três comunidades pesqueiras do município de Rio Grande. Entre setembro de 2010 e dezembro de 2011 foram entrevistados, periodicamente, 10 pescadores de cada comunidade, coletando-se informações sobre a pescaria e a quantidade de pescado consumida. A média de consumo per capita de pescado foi de 109 g dia-1 e 38,57 kg ano-1. O autoconsumo médio diário foi maior na primavera (161 g/pessoa) e no verão (162 g/pessoa), sendo a corvina e o camarão-rosa, respectivamente, as principais espécies consumidas. Os resultados indicaram que o pescado é importante fonte de alimento para os pescadores artesanais das comunidades.

Determination and historical analysis of the common Argentinean hake, Merllucius hubbsi Marini, 1933 (Teleostei, Gadiformes), juvenilesconcentration areas in the Argentinean-Uruguayan common fishing zone, between autumn 1986 and winter 1991 / Determinación y análisis histórico de las áreas de concentración de juveniles de merluza, Merluccius hubbsi Marini, 1933 (Teleostei, Gadiformes), en la zona común de pesca argentino-uruguaya, entre el otoño de 1986 y el invierno de 1991

 Seven surveys for the assessment of the state of the stock of the Argentine hake (Merluccius hubbsi) covering the Argentinean-Uruguayan Common Fishing Zone were analyzed in order to establish the areas of higher juveniles concentrations. For all the cruises, the juveniles concentration areas were found between depths of 50 and 200 m and latitudes 34°18S and 37°20S. The protection of this part of the hakes population is discussed as a precautory measure for the exploitation of this resource by Uruguay and Argentina.

Foram analisadas sete campanhas de prospecção para avaliação do estado do recurso merluza (Merluccius hubbsi) realizadas na Zona Comum de Pesca Argentino-Uruguaia entre 1986 e 1991 para determinar as áreas de maior concentração de juvenis. Para todas as campanhas foram detectadas zonas de alta concentração de juvenis entre 50 e 200 m de profundidade e entre as latitudes de 34°18S e 37°20S. Discute-se sobre a proteção desta parte da população como medida preventiva na exploração do recurso por parte do Uruguai e da Argentina.