Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.

Biology, distribution and geographic variation of loliginid squids (Mollusca: Cephalopoda) off southwestern Atlantic

The biology and ecology of southwestern Atlantic loliginid squids have been intensively researched in the last few decades, mostly off the Brazilian southern coast. However, information gathered by scientific research cruisers, either past or recent, is limited. Three species of loliginid squids - the warm-tempered Doryteuthis sanpaulensis(Brakoniecki, 1984), plus the tropical D. pleii (Blainville, 1823) and Lolliguncula brevis (Blainville, 1823) - were sampled along 16 degrees of latitude on the southwestern Atlantic (22-38°S). The samples were obtained mostly from oceanographic surveys, but also included squids caught by commercial fisheries, and a few specimens from museum collections. Squid response to abiotic variables, morphological variation and circadian behaviour were surveyed in detail. Doryteuthis sanpaulensis can be divided into at least six distinguishable geographical groups, which do not form a cline. In contrast, D. pleii can be divided into only two morphological groups that are very similar. Doryteuthis spp. were heterogeneously distributed on the shelf, whereas L. brevis was confined nearshore. Our data extended the southernmost distribution range of D. pleii by at least nine degrees of latitude, owing to specimens obtained at ~38°S (Mar del Plata, Argentina). Small, immature D. sanpaulensis were sampled inside the Patos Lagoon estuary (~32°S). The morphologically similar Doryteuthis spp. apparently avoid direct competition by concentrating at different depths, displaying different thermal preferences, and inverse circadian levels of activity. The information reported herein may be regarded as a “snapshot” of the ecology of sympatric squids in a marine environment that has not been deeply affected by climate change.(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.(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.

Carbon primary sources and estuarine habitat use by two congeneric ariid catfishes in a subtropical coastal lagoon

Although ariid catfishe species are known to use coastal systems during some stages of their life cycles, the energetic contribution of estuarine resources and habitat use by many species in this family are still unclear. We used stable isotope analyses to estimate the assimilation of primary carbon sources and to infer the use of estuarine and freshwater habitats by two ariid catfishes Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). An isotopic mixing model revealed that juveniles of both catfish species consume considerable amounts of estuarine-produced carbon sources (G. barbus: 54-87% and G. genidens: 36-84%). However, G. genidens adults rely more on freshwater-derived carbon sources (31-77%) than on estuarine sources (23-69%). These results support the hypothesis that both species occupy the estuary and assimilate organic carbon produced in this region during their early stages, but G. genidens adults consume carbon sources associated with the freshwater portion of the lagoon.

Carbon primary sources and estuarine habitat use by two congeneric ariid catfishes in a subtropical coastal lagoon

Although ariid catfishe species are known to use coastal systems during some stages of their life cycles, the energetic contribution of estuarine resources and habitat use by many species in this family are still unclear. We used stable isotope analyses to estimate the assimilation of primary carbon sources and to infer the use of estuarine and freshwater habitats by two ariid catfishes Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). An isotopic mixing model revealed that juveniles of both catfish species consume considerable amounts of estuarine-produced carbon sources (G. barbus: 54-87% and G. genidens: 36-84%). However, G. genidens adults rely more on freshwater-derived carbon sources (31-77%) than on estuarine sources (23-69%). These results support the hypothesis that both species occupy the estuary and assimilate organic carbon produced in this region during their early stages, but G. genidens adults consume carbon sources associated with the freshwater portion of the lagoon.(AU)

Biodegradation of [D-Leu1] microcystin-LR by a bacterium isolated from sediment of Patos Lagoon estuary, Brazil

Background Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. Methods [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosastrain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu1] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L1 glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. Results Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu1] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu1] microcystin-LR lowered the amount of toxin from 1 g.L1 to 0.05 g.L1. Besides, an increase in the bacterial countfrom 71×105 bacteria.mL1 to 117×105 bacteria.mL1was observed along the incubation. Conclusions The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacteriumof the genus Pseudomonasthat can degrade [D-Leu1] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.(AU)

Biodegradation of [D-Leu1] microcystin-LR by a bacterium isolated from sediment of Patos Lagoon estuary, Brazil

Background Toxic cyanobacterial blooms are recurrent in Patos Lagoon, in southern Brazil. Among cyanotoxins, [D-Leu1] microcystin-LR is the predominant variant whose natural cycle involves water and sediment compartments. This study aimed to identify and isolate from sediment a bacterial strain capable of growing on [D-Leu1] microcystin-LR. Sediment and water samples were collected at two distinct aquatic spots: close to the Oceanographic Museum (P1), in Rio Grande City, and on São Lourenço Beach (P2), in São Lourenço do Sul City, southern Brazil. Methods [D-Leu1] microcystin-LR was isolated and purified from batch cultures of Microcystis aeruginosastrain RST9501. Samples of water and sediment from Rio Grande and São Lourenço do Sul were collected. Bacteria from the samples were allowed to grow in flasks containing solely [D-Leu1] microcystin-LR. This strain named DMSX was isolated on agar MSM with 8 g L1 glucose and further purified on a cyanotoxin basis growth. Microcystin concentration was obtained by using the ELISA immunoassay for microcystins whereas bacterial count was performed by epifluorescence microscopy. The genus Pseudomonas was identified by DNA techniques. Results Although several bacterial strains were isolated from the samples, only one, DMXS, was capable of growing on [D-Leu1] microcystin-LR. The phylogenetic analysis of the 16S rRNA gene from DMXS strain classified the organism as Pseudomonas aeruginosa. DMXS strain incubated with [D-Leu1] microcystin-LR lowered the amount of toxin from 1 g.L1 to 0.05 g.L1. Besides, an increase in the bacterial countfrom 71×105 bacteria.mL1 to 117×105 bacteria.mL1was observed along the incubation. Conclusions The use of bacteria isolated from sediment for technological applications to remove toxic compounds is viable. Studies have shown that sediment plays an important role as a source of bacteria capable of degrading cyanobacterial toxins. This is the first Brazilian report on a bacteriumof the genus Pseudomonasthat can degrade [D-Leu1] microcystin-LR, the most frequent microcystin variant in Brazilian freshwaters.

Vibrio parahaemolyticus isolated from fishes captured from the Lagoa dos Patos estuary / Vibrio parahaemolyticus isolados de pescados do estuário da Lagoa dos Patos

Lagoa dos Patos estuary is an important artisanal fishing pole because it represents an area for breeding several species of fish and shellfish. Water is directly influenced by meteorological factors, which interfere in the ocean water into the estuary and flow, reflecting on the salinity. For this reason, there is the possibility of V. parahaemolyticus be found in the lagoon estuary; consequently the fish caught from these place could offer risks to the health of consumers. The objective of this study was to evaluate the presence of V. parahaemolyticus in the Lagoa dos Patos estuary, and in the fishes captured from small-scale fishing and processing. Fifty-six samples of fish caught from the Lagoa dos Patos estuary were analyzed for the presence of V. parahaemolyticus. Three of five species analyzed, shrimp (Farfantepenaeus paulensis), mullet (Mugil platanus) and sole (Paralichthys orbignyanus) harbored this microorganism. These results serve as a warning for providing the best technical oversight to the production of fish, and also the adoption of hygienic and sanitary measures to prevent the risk of transmission of this pathogen to consumers. This is the first report on the isolation of V. parahaemolyticus from F. paulensis, M. platanus and P.orbignyanus(AU)

O estuário da Lagoa dos Patos é um importante polo pesqueiro artesanal por constituir área de criação de diversas espécies de peixes e crustáceos. Suas águas são influenciadas diretamente por fatores meteorológicos, os quais interferem na entrada de água oceânica no estuário e na vazão, refletindo na sua salinidade. Por esta razão, há a possibilidade de V. parahaemolyticus ser encontrado no estuário da lagoa e, consequentemente, nos pescados nele capturados, o que ofereceria risco aos consumidores. O objetivo do estudo foi de avaliar a presença de V. parahaemolyticus em pescados do estuário da Lagoa dos Patos, capturados e processados artesanalmente. Cinquenta e seis amostras de pescados oriundos do estuário da Lagoa dos Patos foram analisadas quanto à presença de V. parahaemolyticus. Três das cinco espécies analisadas, camarão-rosa (Farfantepenaeus paulensis), tainha (Mugil platanus) e linguado (Paralichthys orbignyanus) albergavam o micro-organismo pesquisado. Estes resultados servem de alerta para a necessidade de maior fiscalização na produção de pescados, bem como da adoção de medidas higiênico-sanitárias que previnam o risco de transmissão deste patógeno para os consumidores. Este é o primeiro registro de isolamento de V. parahaemolyticus de F. paulensis, M. platanus e P. orbignyanus(AU)

Metazoan parasites of Geophagus brasiliensis (Perciformes: Cichlidae) in Patos lagoon, extreme south of Brazil / Metazoários parasitos de Geophagus brasiliensis (Perciformes: Cichlidae) da Lagoa dos Patos, extremo sul do Brasil

This study has evaluated the parasitic fauna of 79 pearl cichlids (Geophagus brasiliensis) from the estuary of Patos Lagoon (31° 57' S and 52° 06' W), Rio Grande do Sul, Brazil, during the months of May and June in 2011 and 2012. All the hosts analyzed were infected with at least one species of parasite. A total of eleven metazoa were identified in 459 specimens collected. The trematode Austrodiplostomum compactum (34.2%) and ergasilids Ergasilus lizae (32.9%) and Gauchergasilus lizae (32.9%) were the most prevalent species. The trematodes Thometrema overstreeti and Posthodiplostomum sp. had significantly higher prevalence in fish longer than 20 cm. The sex of the host had no effect on parasite prevalence and abundance. Pearl cichlids are registered as a new host for the trematodes Lobatostoma sp., Homalometron pseudopallidum and Thometrema overstreeti, for the ergasilids Ergasilus lizae and Gauchergasilus euripedesi and for the argulid Argulus spinolosus. The crustacean E. lizae is recorded in Rio Grande do Sul for the first time. (AU)

Este estudo avaliou a fauna parasitária de 79 Geophagus brasiliensis (acarás) proveniente do Estuário da Lagoa dos Patos (31°57S e 52°06W), Rio Grande do Sul, no período de Maio e Junho de 2011 a 2012. Todos os hospedeiros analisados estavam infectados com pelo menos uma espécie de parasito. Um total de onze metazoários foi identificado em 459 espécimes coletados. O trematoda Austrodiplostomum compactum (34,2%) e os ergasilídeos Ergasilus lizae (32,9%) e Gauchergasilus lizae (32,9%) foram às espécies mais prevalentes. Os trematodeos Thometrema overstreeti e Posthodiplostomum sp. apresentaram uma prevalência significativamente maior nos peixes acima de 20 cm. O gênero sexual dos hospedeiros não apresentou influência sobre a prevalência e a abundância parasitária. Geophagus brasiliensis é registrado como um novo hospedeiro para os trematódeos Lobatostoma sp., Homalometron pseudopallidum e Thometrema overstreeti, para os ergasilídeos Ergasilus lizae e Gauchergasilus euripedesi e para o argulídeo Argulus spinolosus. O crustáceo E. lizae é registrado pela primeira vez no Rio Grande do Sul. (AU)

Biologia reprodutiva do siri-azul Callinectes sapidus no estuário da Lagoa dos Patos, RS, Brasil / Reproductive biology of the blue crab Callinectes sapidus on the Patos Lagoon Estuary, RS, Brazil

In this study the reproductive state and the gonad relations of Callinectes sapidus were determinated on the estuary and oceanic adjacent area on the Patos Lagoon, RS, Brazil, from catch per unit of effort and fecundity data. Monthly samples were collected from April of 2008 to April of 2010. The size of carapace at first maturation (LC50) of the blue crab was estimated in 108 mm for males and 115 mm for females. There was an increase in the gonadosomatic relation during winter months, and a decrease during summer months. The gonad relation allows inferring that the copula and gonad development is delimited between winter and spring. Through the analysis of the proportion of gonad development stage, the majority of the females from the beginning of winter presented immature gonad, whereas in the summer, the majority of analyzed females had gonad in rest, indicating recent spawning. The species presents a well marked seasonal reproduction for the estuary, with males maturing at a smaller size than females. In the reproductive season of 2008, there was a balance between the sex ratio, which was not repeated in the 2009 season. It is possible that such phenomenon occurs due to the high volume of rainfall recorded during that period, causing migration of females to higher salinities for spawning. Callinectes sapidus is sensitive to environmental alterations, and longer periods of rainfall combined with other factors like low salinity and temperature can endanger future breeds.(AU)

Foi observado o estado reprodutivo e definidas as relações gonadais de Callinectes sapidus no estuário e área oceânica adjacente da Lagoa dos Patos, RS, a partir de dados de captura por unidade de esforço e fecundidade. Foram realizadas coletas mensais entre abril de 2008 e abril de 2010. O tamanho de primeira maturação (LC50) do siri-azul foi estimado em 108 mm de largura de carapaça para machos e 115 mm para fêmeas. Houve um aumento na relação gonadossomática durante os meses de inverno e uma diminuição durante os meses de verão. A relação gonadal permite inferir que o período de cópula e desenvolvimento gonadal está delimitado entre o inverno e a primavera. Pela proporção dos estádios de desenvolvimento das gônadas no início do inverno, a maior parte das fêmeas apresentou gônadas imaturas, enquanto que no verão, a maioria das fêmeas analisadas possuía gônada em repouso, indicando desova recente. A espécie apresenta reprodução sazonal bem marcada para o estuário, com machos maturando com tamanho menor do que as fêmeas. Na temporada reprodutiva de 2008 notou-se um equilíbrio entre o número de machos e fêmeas no interior do estuário, o que não se repetiu na temporada de 2009, talvez pelo alto volume de chuvas registrado neste período, que pode ter causado a migração de fêmeas em busca de salinidades mais elevadas para desova. Callinectes sapidus é sensível a alterações ambientais, e prolongados períodos de chuva, combinados com outros fatores ambientais comodiminuição de salinidade, podem comprometer o estoque.(AU)

Biologia reprodutiva do siri-azul Callinectes sapidus no estuário da Lagoa dos Patos, RS, Brasil / Reproductive biology of the blue crab Callinectes sapidus on the Patos Lagoon Estuary, RS, Brazil

In this study the reproductive state and the gonad relations of Callinectes sapidus were determinated on the estuary and oceanic adjacent area on the Patos Lagoon, RS, Brazil, from catch per unit of effort and fecundity data. Monthly samples were collected from April of 2008 to April of 2010. The size of carapace at first maturation (LC50) of the blue crab was estimated in 108 mm for males and 115 mm for females. There was an increase in the gonadosomatic relation during winter months, and a decrease during summer months. The gonad relation allows inferring that the copula and gonad development is delimited between winter and spring. Through the analysis of the proportion of gonad development stage, the majority of the females from the beginning of winter presented immature gonad, whereas in the summer, the majority of analyzed females had gonad in rest, indicating recent spawning. The species presents a well marked seasonal reproduction for the estuary, with males maturing at a smaller size than females. In the reproductive season of 2008, there was a balance between the sex ratio, which was not repeated in the 2009 season. It is possible that such phenomenon occurs due to the high volume of rainfall recorded during that period, causing migration of females to higher salinities for spawning. Callinectes sapidus is sensitive to environmental alterations, and longer periods of rainfall combined with other factors like low salinity and temperature can endanger future breeds.

Foi observado o estado reprodutivo e definidas as relações gonadais de Callinectes sapidus no estuário e área oceânica adjacente da Lagoa dos Patos, RS, a partir de dados de captura por unidade de esforço e fecundidade. Foram realizadas coletas mensais entre abril de 2008 e abril de 2010. O tamanho de primeira maturação (LC50) do siri-azul foi estimado em 108 mm de largura de carapaça para machos e 115 mm para fêmeas. Houve um aumento na relação gonadossomática durante os meses de inverno e uma diminuição durante os meses de verão. A relação gonadal permite inferir que o período de cópula e desenvolvimento gonadal está delimitado entre o inverno e a primavera. Pela proporção dos estádios de desenvolvimento das gônadas no início do inverno, a maior parte das fêmeas apresentou gônadas imaturas, enquanto que no verão, a maioria das fêmeas analisadas possuía gônada em repouso, indicando desova recente. A espécie apresenta reprodução sazonal bem marcada para o estuário, com machos maturando com tamanho menor do que as fêmeas. Na temporada reprodutiva de 2008 notou-se um equilíbrio entre o número de machos e fêmeas no interior do estuário, o que não se repetiu na temporada de 2009, talvez pelo alto volume de chuvas registrado neste período, que pode ter causado a migração de fêmeas em busca de salinidades mais elevadas para desova. Callinectes sapidus é sensível a alterações ambientais, e prolongados períodos de chuva, combinados com outros fatores ambientais comodiminuição de salinidade, podem comprometer o 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.

Abundance, breeding and food of the Little Blue Heron Egretta caerulea (Aves, Ardeidae) in the Patos Lagoon estuary, a recently colonized area in southern Brazil

We document the expansion of the breeding distribution of the Little Blue Heron Egretta caerulea (Linnaeus, 1758) to 850 km beyond its previous southern limit in South America. In addition we present data on abundance, breeding biology and food of the species in the Patos Lagoon estuary, the area which the species recently colonized. The maximum abundance recorded in the breeding colony and in a nocturnal roosting site was 53 and 49 individuals respectively. Nesting occurred from September to March. Birds nested in a mixed breeding colony together with about 3,000 breeding pairs of seven other species of Pelecaniformes, in a swampy forest near the margin of the estuary. Five nests were between 1.5 and 4.3 m from the ground, on the shrub Daphnopsis racemosa (Thymelaeaceae), on the trees Sebastiana brasiliensis (Euphorbiaceae) and Mimosa bimucronata (Leguminosae), or on the bamboo Bambusa sp. (Poaceae). Four nests produced two fledglings each, while one nest was abandoned. Of 13 grouped samples of food regurgitated by five nestlings, Pink Shrimp Farfantepenaeus paulensis (Perez-Farfante, 1967) constituted 70% in mass, while total length of ingested fishes and shrimps varied mostly between 20 and 50 mm. Estuarine prey items represented 99% of the total food mass. The recent southward expansion of the breeding range of the Little Blue Heron in South America may be a response to climate warming of the Patos Lagoon estuary. Degradation of estuaries in the southwestern Atlantic may also be forcing the birds to breed in areas outside previous geographical range.

No presente trabalho é documentada a expansão da distribuição reprodutiva da garça-azul Egretta caerulea (Linnaeus, 1758) 850 km para o sul das colônias mais austrais previamente conhecidas. Adicionalmente, são apresentadas informações sobre abundância, reprodução e alimentação da espécie no estuário da Lagos dos Patos, região recentemente colonizada no extremo sul do Brasil. As garças-azuis nidificaram em uma colônia multiespecífica localizada em uma mata paludosa às margens do estuário, contendo outras sete espécies de Pelecaniformes, totalizando cerca de 3.000 pares reprodutivos. O período reprodutivo se estendeu de setembro até fins de março, e as maiores abundâncias registradas na colônia e no dormitório foram 53 e 49 indivíduos, respectivamente. Foram encontrados cinco ninhos, construídos sobre árvores Sebastiana brasiliensis (Euphorbiaceae) ou Mimosa bimucronata (Leguminosae), arbustos Daphnopsis racemosa (Thymelaeaceae), ou bambus Bambusa sp. (Poaceae), em alturas entre 1,5 e 4,3 m acima do solo. Quatro ninhos produziram dois filhotes cada, e um foi abandonado. Em uma análise preliminar da dieta, baseada em 13 amostras de alimento regurgitado de cinco filhotes, verificou-se que camarões-rosa Farfantepenaeus paulensis (Perez-Farfante, 1967) corresponderam a 70% das presas consumidas, e os itens alimentares de origem estuarina constituíram 99% da biomassa ingerida. Todos os peixes e a maioria dos camarões consumidos possuíam comprimento total entre 20 e 50 mm. A recente expansão da distribuição reprodutiva da garça-azul em direção ao sul pode ter sido favorecida pelo aquecimento climático observado na região do estuário da Lagoa dos Patos, e influenciado pela degradação dos estuários no Atlântico sudoeste nas últimas décadas, levando as aves a colonizarem áreas fora da sua distribuição habitual.

Abundance, breeding and food of the Little Blue Heron Egretta caerulea (Aves, Ardeidae) in the Patos Lagoon estuary, a recently colonized area in southern Brazil

We document the expansion of the breeding distribution of the Little Blue Heron Egretta caerulea (Linnaeus, 1758) to 850 km beyond its previous southern limit in South America. In addition we present data on abundance, breeding biology and food of the species in the Patos Lagoon estuary, the area which the species recently colonized. The maximum abundance recorded in the breeding colony and in a nocturnal roosting site was 53 and 49 individuals respectively. Nesting occurred from September to March. Birds nested in a mixed breeding colony together with about 3,000 breeding pairs of seven other species of Pelecaniformes, in a swampy forest near the margin of the estuary. Five nests were between 1.5 and 4.3 m from the ground, on the shrub Daphnopsis racemosa (Thymelaeaceae), on the trees Sebastiana brasiliensis (Euphorbiaceae) and Mimosa bimucronata (Leguminosae), or on the bamboo Bambusa sp. (Poaceae). Four nests produced two fledglings each, while one nest was abandoned. Of 13 grouped samples of food regurgitated by five nestlings, Pink Shrimp Farfantepenaeus paulensis (Perez-Farfante, 1967) constituted 70% in mass, while total length of ingested fishes and shrimps varied mostly between 20 and 50 mm. Estuarine prey items represented 99% of the total food mass. The recent southward expansion of the breeding range of the Little Blue Heron in South America may be a response to climate warming of the Patos Lagoon estuary. Degradation of estuaries in the southwestern Atlantic may also be forcing the birds to breed in areas outside previous geographical range.

No presente trabalho é documentada a expansão da distribuição reprodutiva da garça-azul Egretta caerulea (Linnaeus, 1758) 850 km para o sul das colônias mais austrais previamente conhecidas. Adicionalmente, são apresentadas informações sobre abundância, reprodução e alimentação da espécie no estuário da Lagos dos Patos, região recentemente colonizada no extremo sul do Brasil. As garças-azuis nidificaram em uma colônia multiespecífica localizada em uma mata paludosa às margens do estuário, contendo outras sete espécies de Pelecaniformes, totalizando cerca de 3.000 pares reprodutivos. O período reprodutivo se estendeu de setembro até fins de março, e as maiores abundâncias registradas na colônia e no dormitório foram 53 e 49 indivíduos, respectivamente. Foram encontrados cinco ninhos, construídos sobre árvores Sebastiana brasiliensis (Euphorbiaceae) ou Mimosa bimucronata (Leguminosae), arbustos Daphnopsis racemosa (Thymelaeaceae), ou bambus Bambusa sp. (Poaceae), em alturas entre 1,5 e 4,3 m acima do solo. Quatro ninhos produziram dois filhotes cada, e um foi abandonado. Em uma análise preliminar da dieta, baseada em 13 amostras de alimento regurgitado de cinco filhotes, verificou-se que camarões-rosa Farfantepenaeus paulensis (Perez-Farfante, 1967) corresponderam a 70% das presas consumidas, e os itens alimentares de origem estuarina constituíram 99% da biomassa ingerida. Todos os peixes e a maioria dos camarões consumidos possuíam comprimento total entre 20 e 50 mm. A recente expansão da distribuição reprodutiva da garça-azul em direção ao sul pode ter sido favorecida pelo aquecimento climático observado na região do estuário da Lagoa dos Patos, e influenciado pela degradação dos estuários no Atlântico sudoeste nas últimas décadas, levando as aves a colonizarem áreas fora da sua distribuição habitual.

Abundance of bottlenose dolphins, Tursiops truncatus (Cetacea: Delphinidae), inhabiting the Patos Lagoon estuary, southern Brazil: implications for conservation

A new mark-recapture abundance estimate and a photographic census were carried out to investigate the possible decline in the abundance of the bottlenose dolphins, Tursiops truncatus (Montagu, 1821), in the Patos Lagoon estuary due to the high levels of bycatch mortality which occurred between 2002 and 2006 in oceanic coastal areas close to the estuary. Fourteen systematic boat surveys were conducted between August and early December 2005 to photo-identify the bottlenose dolphins. The estimated number of animals, with long-lasting marks, in the population obtained from Chapman's and Mth models were 51 (95% CI = 49-53) and 52 (95% CI = 51-60), respectively. Taking into account the proportion of dolphins with long-lasting marks in the population, the total estimated population size ranged between 84 (95% CI = 76-93) and 86 (95% CI = 78-95) individuals, respectively, which was very similar to the 84 individuals revealed by the population census. Our results did not differ from the abundance estimate carried out in 1998, prior to the high fishing-related mortality event, suggesting that the population is stable. Plausible argument to explain the stability of the population is that some carcasses found on the oceanic coastal beaches near Patos Lagoon estuary come from animals that do not belong to the estuary community. Future studies should investigate fine-scale habitat partition between estuarine and adjacent coastal dolphins. If the existence of different communities living in close proximity (estuarine and coastal areas near to the estuary) is confirmed, a new abundance estimate is needed to access the conservation status of bottlenose dolphins in this region.

Abundance of bottlenose dolphins, Tursiops truncatus (Cetacea: Delphinidae), inhabiting the Patos Lagoon estuary, southern Brazil: implications for conservation

A new mark-recapture abundance estimate and a photographic census were carried out to investigate the possible decline in the abundance of the bottlenose dolphins, Tursiops truncatus (Montagu, 1821), in the Patos Lagoon estuary due to the high levels of bycatch mortality which occurred between 2002 and 2006 in oceanic coastal areas close to the estuary. Fourteen systematic boat surveys were conducted between August and early December 2005 to photo-identify the bottlenose dolphins. The estimated number of animals, with long-lasting marks, in the population obtained from Chapman's and Mth models were 51 (95% CI = 49-53) and 52 (95% CI = 51-60), respectively. Taking into account the proportion of dolphins with long-lasting marks in the population, the total estimated population size ranged between 84 (95% CI = 76-93) and 86 (95% CI = 78-95) individuals, respectively, which was very similar to the 84 individuals revealed by the population census. Our results did not differ from the abundance estimate carried out in 1998, prior to the high fishing-related mortality event, suggesting that the population is stable. Plausible argument to explain the stability of the population is that some carcasses found on the oceanic coastal beaches near Patos Lagoon estuary come from animals that do not belong to the estuary community. Future studies should investigate fine-scale habitat partition between estuarine and adjacent coastal dolphins. If the existence of different communities living in close proximity (estuarine and coastal areas near to the estuary) is confirmed, a new abundance estimate is needed to access the conservation status of bottlenose dolphins in this region.

Abundance of bottlenose dolphins, Tursiops truncatus (Cetacea: Delphinidae), inhabiting the Patos Lagoon estuary, southern Brazil: implications for conservation

A new mark-recapture abundance estimate and a photographic census were carried out to investigate the possible decline in the abundance of the bottlenose dolphins, Tursiops truncatus (Montagu, 1821), in the Patos Lagoon estuary due to the high levels of bycatch mortality which occurred between 2002 and 2006 in oceanic coastal areas close to the estuary. Fourteen systematic boat surveys were conducted between August and early December 2005 to photo-identify the bottlenose dolphins. The estimated number of animals, with long-lasting marks, in the population obtained from Chapman's and Mth models were 51 (95% CI = 49-53) and 52 (95% CI = 51-60), respectively. Taking into account the proportion of dolphins with long-lasting marks in the population, the total estimated population size ranged between 84 (95% CI = 76-93) and 86 (95% CI = 78-95) individuals, respectively, which was very similar to the 84 individuals revealed by the population census. Our results did not differ from the abundance estimate carried out in 1998, prior to the high fishing-related mortality event, suggesting that the population is stable. Plausible argument to explain the stability of the population is that some carcasses found on the oceanic coastal beaches near Patos Lagoon estuary come from animals that do not belong to the estuary community. Future studies should investigate fine-scale habitat partition between estuarine and adjacent coastal dolphins. If the existence of different communities living in close proximity (estuarine and coastal areas near to the estuary) is confirmed, a new abundance estimate is needed to access the conservation status of bottlenose dolphins in this region.

Diet and feeding strategy of the dusky grouper Mycteroperca marginata (Actinopterygii: Epinephelidae) in a man-made rocky habitat in southern Brazil

A garoupa-verdadeira (Mycteroperca marginata) é uma espécie marinha geralmente associada a fundos rochosos e recifes. O presente trabalho investiga a dieta e estratégia alimentar de uma população da garoupa-verdadeira que habita um longo (4,5 km) par de molhes de pedra na desembocadura do estuário da laguna dos Patos, sul do Brasil. Não há trabalhos anteriores realizados nesse tipo de habitat construído pelo homem e este trabalho fornece uma base de comparação com estudos de dieta de outras populações da garoupa-verdadeira ocorrendo em habitats naturais. De modo similar ao encontrado em estudos prévios realizados em substratos naturais, caranguejos e peixes foram as principais categorias de alimento consumidas (%IRI = 85,1 e %IRI = 12,6, respectivamente), enquanto camarões e moluscos tiveram menor importância na dieta (%IRI = 1,9 e %IRI = 0,4, respectivamente). Como reportado anteriormente para populações de garoupa-verdadeira que habitam recifes e fundos rochosos, o presente trabalho revelou marcadas mudanças na dieta em função do tamanho da espécie. Siri-azul e peixes tornam-se gradativamente mais importantes na dieta de indivíduos maiores (> 500 mm de comprimento total, CT). Finalmente, foi observado que a população de garoupa-verdadeira teve uma estratégia alimentar generalista com uma elevada variação entre indivíduos no consumo de presas. Essa estratégia permaneceu similar ao longo do aumento em tamanho da espécie. Os resultados do presente trabalho sugerem que substratos rochosos estabelecidos pelo homem propiciam locais de alimentação adequados para a garoupa-verdadeira no sul do Brasil e que poderiam ser usados como ferramentas adicionais nos esforços de conservação dessa espécie ameaçada.(AU)

The dusky grouper (Mycteroperca marginata) is a marine species usually associated with rocky bottoms and reefs. The present work investigated the diet and feeding strategy of a dusky grouper population inhabiting a 4.5 km long pair of rocky jetties located in the mouth of Patos Lagoon estuary. No prior research has been conducted in such man-made habitat and the current study provides a basis for comparative studies on the diet of the dusky grouper populations inhabiting natural vs. manmade rocky habitats. Similarly with previous studies on natural substrates, crabs and fishes were the main food categories consumed (%IRI = 85.1 and %IRI = 12.6, respectively), whereas shrimps and mollusks had lower importance in the diet (%IRI = 1.9 and 0.4, respectively). As previously reported for dusky grouper populations inhabiting reefs and rocky bottoms, the present work revealed conspicuous size related dietary shifts. Blue crabs and fishes become increasingly important food itemsin the diet of larger individuals (> 500 mm, TL). Finally, it was found that the studied dusky population has a generalist feeding strategy with a high between-individual variation in prey consumption. Such strategy remained similar across the size increment of the species. Our findings suggest that man-made rocky substrates provide suitable feeding grounds for the dusky grouper in southern Brazil and could be used as an additional tool in the conservation efforts of this endangered species.(AU)

Efluentes da Carcinocultura e seus Efeitos sobre o Sistema Estuarino da Lagoa dos Patos

A aquicultura é o setor de produção de alimentos de origem animal que mais cresce no mundo. A carcinocultura, como parte desse setor, tem gerado diversos benefícios em termos sócio-econômicos, mas também tem gerado uma atenção especial aos aspectos ambientais envolvidos com a atividade. A produção em cativeiro do camarão branco do Pacífico Litopenaeus vannamei vem se consolidando cada vez mais no entorno do estuário da Lagoa dos Patos, região sul do Brasil. Esse estuário possui importância ecológica, industrial, portuária, agrícola e pesqueira, o que torna necessário a compreensão do potencial impacto poluidor da atividade nessa região. Nesse estudo, parâmetros de qualidade da água, composição e abundância do fitoplâncton, protozooplâncton, mesozooplâncton e macrozoobentos foram avaliados espaço13 temporalmente no corpo d`água receptor dos efluentes de uma fazenda produtora de camarões da espécie Litopenaeus vannamei localizada as margens do estuário da Lagoa dos Patos. Foram avaliados ainda os teores de carbono orgânico total (COT), nitrogênio total (NT), Cobre (Cu) e Zinco (Zn) do sedimento do viveiro de cultivo, da bacia de sedimentação e do estuário receptor dos efluentes. Foram avaliadas ainda as concentrações de Cu e Zn do tecido dos camarões cultivados ao final do ciclo produtivo. As amostras foram tomadas antes da descarga dos efluentes (AD) e; 1 dia (1 PD), 5 dias (5 PD), 10 dias (10 PD), 20 dias (20 PD), 30 dias (30 PD), 60 dias (60 PD) e 90 dias (90 PD) após a descarga dos efluentes. Vale ressaltar que cada estudo contou com um cronograma próprio e assim nem todas as análises citadas acima tiveram coletas em todas as datas mencionadas. Especificamente para a avaliação do macrozoobentos, um segundo ciclo de produção foi acompanhado para realização de amostragens. Os pontos de coleta no estuário distribuíram-se desde a desembocadura do canal de lançamento dos efluentes até uma distância de 250 m do mesmo. Dados de temperatura, oxigênio dissolvido, pH, salinidade, clorofila a, nitrogênio amoniacal total (NAT), nitrito, nitrato, fósforo total, sólidos suspensos totais e turbidez da água foram mensurados. Além da temperatura e salinidade que sofrem variações sazonais em ambientes estuarinos, NAT, clorofila a e turbidez foram os parâmetros de qualidade de água que sofreram alterações mais marcadas em decorrência do lançamento dos efluentes. No entanto, de maneira geral, essas alterações foram restritas a uma distância de até 20 m do canal de descarga dos efluentes por um período de tempo de no máximo 5 dias. Diatomáceas, cianobactérias, clorofíceas e ciliados foram identificados e quantificados. A comunidade predominante foi a de clorofíceas, seguido das diatomáceas, cianobactérias 1 e ciliados.Houve um aumento na concentração dos diferentes grupos no primeiro dia pós-descarga (1 PD). Entretanto, esse aumento pode estar relacionado ao enriquecimento de nutrientes das águas estuarinas ocasionado por chuvas abundantes, e não propriamente ao despejo dos efluentes. A abundância meso-zooplanctônica foi baixa e representada exclusivamente por copépodos, na sua grande maioria da espécie Acartia tonsa. A únic exceção foi a amostragem 30 PD que sofreu um acréscimo expressivo, sem no entanto apresentar relação com os parâmetros abióticos avaliados. Apesar de diferenças significativas (p < 0,05) terem sido observadas em algumas amostragens, essas não aparentam ter nenhuma relação com o lançamento dos efluentes. Sete grupos macrozoobentônicos foram observados (Polychaeta, Tanaidacea, Isopoda, Gastropoda, Bivalvia, Malacostraca e Ostracoda) ao longo de dois ciclos produtivos (2012 e 2013). A densidade e a riqueza de espécies sofreram pequena variabilidade ao longo dos pontos amostrais do estuário para ambas as etapas. Já ao longo do tempo, em 2012 pode-se observar um aumento desses índices no inverno comparativamente ao verão. Ao longo das coletas de 2013, a densidade do macrobentos teve um padrão oposto e a riqueza de espécies sofreu pouca variabilidade. A concentração de COT variou de 0,12 a 0,67% e a concentração de NT ficou abaixo do limite de detecção do equipamento (<0,1 ppm) em todos os locais e campanhas amostrais. Os teores de Cu e Zn no sedimento foram quantificados através de extração fraca (fração de metais lábeis ou potencialmente biodisponível) e extração semi-forte (fração de metais mais fortemente adsorvida). O Cu na fração lábil variou de 0,12 a 1,27 g/g e o Zn variou de 0,52 a 3 g/g, enquanto que a fração mais fortemente adsorvida de Cu variou de 0,3 a 2.65 g/g e o Zn de 30,44 a 121,4 g/g. Diferenças significativas (ANOVA, p < 0,05) foram observadas nos resultados de COT entre alguns pontos amostrais nas campanhas 1PD e 10PD, sem no entanto haver relação com o lançamento dos efluentes. A análise de correlação de Pearson não mostrou relação entre o lançamento dos efluentes e aumento nos valores de COT, NT, Cu ou Zn no sedimento, com exceção da relação encontrada entre os valores de COT e Cu e Zn no sedimento no primeiro dia pós-descarga (1 PD). Ao final do ciclo, exemplares de camarões coletados de dois viveiros de engorda revelaram concentrações médias de 6,63±0,2 g/g de Cu e 19,76±0,2 g/g de Zn no viveiro 1, e 7,6±0,51 g/g de Cu e 19,13±0,32 g/g de Zn no viveiro 2. Apesar de alguns parâmetros de qualidade de água terem sofrido variações em decorrência do lançamento dos efluentes, esses efeitos foram agudos e pontuais, restritos a uma distância de até 20m da margem e observados até os 1 5 dias após o descarte dos efluentes. Além disso, os valores ficaram dentro da faixa exigida pela Resolução ambiental vigente. O fitoplâncton, protozooplâncton, mesozooplâncton e o macrozoobentos sofreram apenas variações decorrentes das oscilações naturais dos parâmetros abióticos que ocorrem em sistemas estuarinos. Por fim, os teores de COT, NT, Cu e Zn no sedimento e Cu e Zn no tecido dos camarões ficaram dentro dos valor máximos estipulados na legislação, mostrando que o lançamento dos efluent provenientes da produção de camarões no entorno do estuário da Lagoa dos Patos não trouxe efeitos adversos ao meio ambiente.

Aquaculture is the food producing sector of higher growth worldwide. The shrimp farming, as part of this sector, has generated several socio-economic benefits. However, it has also developed particular attention to environmental aspects involved with the activity. The production of Pacific white shrimp Litopenaeus vannamei is increasing in areas adjacent to Patos Lagoon estuary, Southern Brazil. This estuary has importance on several areas as ecology, industry, ports, agriculture and fisheries, which makes the understanding of the potential pollution impact of the shrimp farm in this ecosystem extremely necessary. In this study, the water quality, composition and abundance of phytoplankton, protozooplankton, meso-zooplankton and macrozoobenthos were spatio12 temporally evaluated in the Patos Lagoon estuary, which received effluents from a commercial shrimp farm. Total organic carbon (TOC), total nitrogen (TN), copper (Cu) and zinc (Zn) content in sediment of pond, sedimentation basin and the estuary were also analyzed. Moreover, concentrations of Cu and Zn in shrimp tissues were measured at the end of the growth out cycle. Samples were taken before the effluents discharge (BD) and; 1 day (1 PD) 5 days (5 PD), 10 days (10 PD), 20 days (20 PD), 30 days (30 PD), 60 days (60 PD) and 90 days (90 PD) after the effluents discharge. Only for the macrozoobenthos analysis, samples were collected in two cycles period. The sampling sites in the estuary were distributed across the effluents discharge channel (EDC), 20m, 30m, 100m and 250m from the channel. Temperature, dissolved oxygen, pH, salinity, chlorophyll a, total ammonia nitrogen (TAN), nitrite, nitrate, total phosphorus, total suspended solids and turbidity were measured. Temperature and salinity suffered seasonal influences and TAN, chlorophyll a and turbidity showed the most marked changes because of the effluents discharge. However, these changes were restricted to a distance of 20 m from the EDC for a period of 5 days. Diatoms, cyanobacteria, chlorophyceae and ciliates were identified and quantified. The predominant community was chlorophytes, followed by diatoms, cyanobacteria and ciliates. There was an increase in the abundance of different groups on the 1 PD sampling. However, this may be related to nutrient enrichment of estuarine waters caused by rains, and not necessarily to the effluents discharge. The meso-zooplankton abundance was low and was represented exclusively by copepods, mostly Acartia tonsa species. The only exception was the sampling 30 PD, when the abundance was higher, but there was no relationship with the evaluated abiotic parameters. Seven 1 macrozoobenthic groups were observed (Polychaeta, Tanaidacea, Isopoda, Gastropoda, Bivalvia, Malacostraca and Ostracoda) over two cycles period (2012 and 2013). Spatially, the density and species richness suffered little variability over the sampling sites in the estuary for both campaigns. Temporarily, it was observed an increase in these indices in winter compared to summer in 2012. Over the 2013 samples, the macrozoobenthos density had an opposite pattern and species richness was little variable. The TOC concentration ranged from 0.12 to 0.67% and the concentration of TN was below the equipment detection limit (<0.1 ppm) in all sampling sites. The contents of Cu and Zn in the sediment were quantified by weak extraction (labile fraction or potentially bioavailable) and semi-strong extractio (more strongly adsorbed fraction). Cu in the labile fraction ranged from 0.12 to 1.27 g g-1 and Zn ranged from 0.52 to 3 g g-1, while in the more strongly adsorbed fraction, Cu ranged from 0.3 to 2.65 g g-1 and Zn from 30.44 to 121.4 g g-1. Significant differences (ANOVA, p <0.05) were observed in the TOC values among sites in samplings 1PD and 10PD, but not related to the effluents discharge. The Pearson correlation analysis showed no relationship between the effluents discharge and increase in TOC, TN, Cu or Zn in the sediment, except for the relation found between the values of TOC, Cu and Zn in the sediment on 1 PD sampling. At the end of the cycle period, shrimps were collected from two ponds and after the tissue analysis it revealed mean concentrations of 6.63 ± 0.2 g g-1 of Cu and 19.76 ± 0.2 g g-1 of Zn in pond 1 and 7, 6 ± 0.51 g g-1 of Cu and 19.13 ± 0.32 g g-1 of Zn in pond 2. Although some water quality parameters have suffered variations due to the effluents discharge, these effects were acute and punctual, restricted to a distance of 20m from the EDC and observed until 5 days after the discharge. In addition, all values were within the limits stipulated by standard guidelines and available Brazilian legislation. Phytoplankton, protozooplankton, meso-zooplankton and the macrozoobenthos showed natural fluctuations related to abiotic parameters in estuarine systems. Finally, TOC, TN, C and Zn in the sediment and Cu and Zn in the shrimp tissue were within the maximum amounts stipulated by standard guidelines, showing that the effluents discharge from the commercial shrimp farm in Patos Lagoon estuary did not cause negative impacts on th environment.