Fishing in the largest perene hypersaline lagoon in South america, with notes on current regulations / A pesca na maior lagoa hipersalina perene da América do sul, com notas sobre a regulamentação vigente

Araruama Lagoon (Rio de Janeiro) is the largest hypersaline lagoon in South America. The aim of this study was to survey fishing landings, capture areas and production at this lagoon, in addition to analyzing data from the Pescarte Census. Fishing landings were monitored daily by community agents from March to August/2009, through the Petrobras Mosaico Program. Thirteen landing points were identified in five municipalities, totaling 8,096 recorded landings, and accumulating 469.1 tonnes. São Pedro da Aldeia (39.6%), Arraial do Cabo (27.7%) and areas in the central region (37.6%) and the south coast (29.1%) of the lagoon presented the highest landings and catch volumes. Twelve species were identified, mainly Pogonias courbina (48.9%) and Penaeus spp. (33.8%), and gillnets were the most important fishing gear. Very few studies have addressed fishing at Araruama Lagoon, leading to current planning measures supported by little data. We advocate a participatory review of current regulations, to better address gillnet fishing and the capture of different fish species. This study is the result of research financed by the Pescarte Environmental Education Project, a mitigation measure required by the Federal Environmental Licensing, conducted by IBAMA.

A Lagoa de Araruama (Rio de Janeiro) é a maior lagoa hipersalina da América do Sul. O objetivo do estudo foi levantar os pontos de desembarque pesqueiro, áreas de captura e a produção da lagoa, além de analisar dados do Censo Pescarte. Por meio do Programa Petrobras Mosaico foi acompanhado o desembarque pesqueiro de março a agosto/2009, por agentes comunitários, com monitoramento diário da pesca. Foram identificados 13 pontos de desembarque, em cinco municípios, sendo registrados 8.096 desembarques, com 469,1 toneladas. São Pedro da Aldeia (39,6%), Arraial do Cabo (27,7%) e áreas da região central (37,6%) e litoral sul (29,1%) da lagoa apresentaram os maiores desembarques e capturas. Foram identificadas 12 espécies, sendo Pogonias courbina (48,9%) e Penaeus spp. (33,8%) as principais, com a rede de emalhar sendo o petrecho mais importante. Pouquíssimos estudos abordaram à pesca na Lagoa de Araruama; logo, as medidas de ordenamento vigentes estão respaldadas em poucos dados. Defendemos uma revisão participativa da regulamentação, de forma a abordar melhor a pesca de emalhe e a captura de peixes diversos. Este estudo é resultado de pesquisa financiada pelo Projeto de Educação Ambiental Pescarte, que é uma medida de mitigação exigida pelo Licenciamento Ambiental Federal, conduzido pelo IBAMA.

Fishing in the largest perene hypersaline lagoon in South america, with notes on current regulations / A pesca na maior lagoa hipersalina perene da América do sul, com notas sobre a regulamentação vigente

Araruama Lagoon (Rio de Janeiro) is the largest hypersaline lagoon in South America. The aim of this study was to survey fishing landings, capture areas and production at this lagoon, in addition to analyzing data from the Pescarte Census. Fishing landings were monitored daily by community agents from March to August/2009, through the Petrobras Mosaico Program. Thirteen landing points were identified in five municipalities, totaling 8,096 recorded landings, and accumulating 469.1 tonnes. São Pedro da Aldeia (39.6%), Arraial do Cabo (27.7%) and areas in the central region (37.6%) and the south coast (29.1%) of the lagoon presented the highest landings and catch volumes. Twelve species were identified, mainly Pogonias courbina (48.9%) and Penaeus spp. (33.8%), and gillnets were the most important fishing gear. Very few studies have addressed fishing at Araruama Lagoon, leading to current planning measures supported by little data. We advocate a participatory review of current regulations, to better address gillnet fishing and the capture of different fish species. This study is the result of research financed by the Pescarte Environmental Education Project, a mitigation measure required by the Federal Environmental Licensing, conducted by IBAMA.(AU)

A Lagoa de Araruama (Rio de Janeiro) é a maior lagoa hipersalina da América do Sul. O objetivo do estudo foi levantar os pontos de desembarque pesqueiro, áreas de captura e a produção da lagoa, além de analisar dados do Censo Pescarte. Por meio do Programa Petrobras Mosaico foi acompanhado o desembarque pesqueiro de março a agosto/2009, por agentes comunitários, com monitoramento diário da pesca. Foram identificados 13 pontos de desembarque, em cinco municípios, sendo registrados 8.096 desembarques, com 469,1 toneladas. São Pedro da Aldeia (39,6%), Arraial do Cabo (27,7%) e áreas da região central (37,6%) e litoral sul (29,1%) da lagoa apresentaram os maiores desembarques e capturas. Foram identificadas 12 espécies, sendo Pogonias courbina (48,9%) e Penaeus spp. (33,8%) as principais, com a rede de emalhar sendo o petrecho mais importante. Pouquíssimos estudos abordaram à pesca na Lagoa de Araruama; logo, as medidas de ordenamento vigentes estão respaldadas em poucos dados. Defendemos uma revisão participativa da regulamentação, de forma a abordar melhor a pesca de emalhe e a captura de peixes diversos. Este estudo é resultado de pesquisa financiada pelo Projeto de Educação Ambiental Pescarte, que é uma medida de mitigação exigida pelo Licenciamento Ambiental Federal, conduzido pelo IBAMA.(AU)

Influences of the area, shape and connectivity of coastal lakes on the taxonomic and functional diversity of fish communities in Southern Brazil

In this study we investigated the influence of landscape variables on the alpha taxonomic and functional diversity of fish communities in coastal lakes. We built an analytical framework that included possible causal connections among variables, which we analyzed using path analysis. We obtained landscape metrics for the area, shape and connectivity (estuary connectivity and primary connectivity to neighboring lakes) of 37 coastal lakes in the Tramandaí River Basin. We collected fish data from 49 species using standardized sampling with gillnets and obtained a set of traits related to dispersal abilities and food acquisition. The model that best explained the taxonomic diversity and functional richness took into account the shape of the lakes. Functional richness was also explained by estuary connectivity. Functional evenness and dispersion were not predicted by area or connectivity, but they were influenced by the abundant freshwater species. This indicates that all lakes support most of the regional functional diversity. The results highlight the importance of the dispersal process in this lake system and allow the conclusion that considering multiple diversity dimensions can aid the conservation of local and regional fish communities.

Influences of the area, shape and connectivity of coastal lakes on the taxonomic and functional diversity of fish communities in Southern Brazil

In this study we investigated the influence of landscape variables on the alpha taxonomic and functional diversity of fish communities in coastal lakes. We built an analytical framework that included possible causal connections among variables, which we analyzed using path analysis. We obtained landscape metrics for the area, shape and connectivity (estuary connectivity and primary connectivity to neighboring lakes) of 37 coastal lakes in the Tramandaí River Basin. We collected fish data from 49 species using standardized sampling with gillnets and obtained a set of traits related to dispersal abilities and food acquisition. The model that best explained the taxonomic diversity and functional richness took into account the shape of the lakes. Functional richness was also explained by estuary connectivity. Functional evenness and dispersion were not predicted by area or connectivity, but they were influenced by the abundant freshwater species. This indicates that all lakes support most of the regional functional diversity. The results highlight the importance of the dispersal process in this lake system and allow the conclusion that considering multiple diversity dimensions can aid the conservation of local and regional fish communities.(AU)

Bird diversity and conservation in the southern coast of Santa Catarina state, Brazil

Coastal lagoons and their surrounding habitats often harbour high biodiversity and some of the most threatened ecosystems in the world. However, in the Neotropics the biodiversity is often poorly described, lacking even inventories of species which therefore limits the assessment of threats and the stablishment of efficient conservation measures. We present here lists of bird species recorded at ten sites along the under-studied coastal lagoons of southern Santa Catarina, Brazil, collected mainly from October 2012 to March 2018. We present quantitative data for endemic and threatened species, identify migratory status and highlight distributional novelties. In total, we recorded 229 species encompassing 63 families, including twelve species of conservation concern, 11 endemic to the Atlantic Forest or Pampas zoogeographical provinces and 38 migrants. We provide new records of seven rare species in Santa Catarina (Larus atlanticus, Calidris pusilla, Aramides ypecaha, Bubo virginianus, Limnornis curvirostris, Phacellodomus ferrugineigula and Pseudocolopteryx flaviventris) and report the first evidence of occurrence of Schoeniophylax phryganophilus for the State. Based on our findings, we discuss the regional diversity and conservation of the avifauna.(AU)

Bird diversity and conservation in the southern coast of Santa Catarina state, Brazil

Coastal lagoons and their surrounding habitats often harbour high biodiversity and some of the most threatened ecosystems in the world. However, in the Neotropics the biodiversity is often poorly described, lacking even inventories of species which therefore limits the assessment of threats and the stablishment of efficient conservation measures. We present here lists of bird species recorded at ten sites along the under-studied coastal lagoons of southern Santa Catarina, Brazil, collected mainly from October 2012 to March 2018. We present quantitative data for endemic and threatened species, identify migratory status and highlight distributional novelties. In total, we recorded 229 species encompassing 63 families, including twelve species of conservation concern, 11 endemic to the Atlantic Forest or Pampas zoogeographical provinces and 38 migrants. We provide new records of seven rare species in Santa Catarina (Larus atlanticus, Calidris pusilla, Aramides ypecaha, Bubo virginianus, Limnornis curvirostris, Phacellodomus ferrugineigula and Pseudocolopteryx flaviventris) and report the first evidence of occurrence of Schoeniophylax phryganophilus for the State. Based on our findings, we discuss the regional diversity and conservation of the avifauna.

Reproductive dynamics of Lycengraulis grossidens (Clupeiformes: Engraulidae) and Platanichthys platana (Clupeiformes: Clupeidae) in a subtropical coastal lagoon / Dinâmica reprodutiva de Lycengraulis grossidens (Clupeiformes: Engraulidae) e Platanichthys platana (Clupeiformes: Clupeidae) em uma lagoa costeira subtropical

We evaluated the reproductive dynamics of two fish species, Lycengraulis grossidens and Platanichthys platana, in a subtropical freshwater coastal lagoon (Peri Lagoon) in Brazil. Samples were collected from nine sites every two months from June 2008 to April 2012. Different fishing methods were used to capture larvae, juveniles, and adults. Limnological variables were obtained using multiparameter probe. More females than males were collected of both fish species and the chi-square test (2) was used to confirm that the sex ratio was female-biased. Large numbers of maturing and mature fishes were observed in almost every sampling month. The gonadosomatic index (GSI) of L. grossidens was the highest in August, October, and December for females and in October for males, and no significant difference was found across years. The GSI of P. platana showed no significant difference across months for either sex; however, significant differences were recorded in year three (June 2010-April 2011) and year four (June 2011-April 2012) for females and in year three (June 2010-April 2011) for males. For both species, GSI was negatively correlated with temperature and water level. L. grossidens larvae were more abundant in October 2010, showing a positive correlation with water transparency, whereas P. platana larvae were more abundant in June 2011, showing a positive correlation with water transparency and negative correlation with temperature and precipitation. Both species were represented by different stages, including larvae, which confirm that these species reproduce in Peri Lagoon. Reproduction was more pronounced in autumn and winter; however, reproductive activity was evident throughout the sampling period. In conclusion, our results show that abiotic factors strongly influence the temporal pattern of reproductive activity and larval assemblages of both L. grossidens and P. platana in Peri Lagoon, Brazil.(AU)

O objetivo do estudo foi avaliar a dinâmica reprodutiva de Lycengraulis grossidens e Platanichthys platana, na lagoa do Peri, uma lagoa costeira de água doce subtropical do Brasil. As amostras foram coletadas a cada dois meses, de junho/2008 a abril/2012 em nove pontos de amostragem. Para a captura de larvas, juvenis e adultos foram utilizados diferentes apetrechos de pesca. As variáveis limnológicas foram obtidas com sonda multiparâmetro. Estatisticamente, mais fêmeas do que machos foram capturadas para as duas espécies baseado no teste de qui-quadrado (2). Grande número de peixes em maturação e maduros foram comuns em quase todos os meses de coleta. O índice gonadossomático (RGS) de L. grossidens variou significativamente apenas entre os meses, sendo mais elevada em agosto, outubro e dezembro para as fêmeas e em outubro para os machos; e não foram encontradas diferenças significativas entre os anos. Não foi encontrado diferença significativa para o RGS de P. platana entre os meses para cada sexo; entretanto, diferenças significativas foram obtidas para as fêmeas no ano três (junho 2010-abril 2011) e quatro (junho 2011-abril 2012) e no ano três (junho 2010-abril 2011) para os machos. Para as duas espécies, o RGS apresentou uma correlação negativa com a temperatura e o nível de água. A distribuição das larvas apresentou variação temporal. As larvas de L. grossidens foram mais abundantes em outubro/2010, apresentando correlação positiva com a transparência da água. As larvas da espécie P. platana foram mais abundantes em junho/2011, apresentando correlação positiva com a transparência da água e negativa com a temperatura e a precipitação. A presença de L. grossidens e P. platana em diferentes estádios de maturação e a ocorrência de larvas confirmou que essas espécies se reproduzem na lagoa do Peri. O período reprodutivo foi mais pronunciado no outono e no inverno, porém a atividade reprodutiva ocorreu durante todo o período de coleta. Em conclusão, nossos resultados mostraram que os fatores abióticos influenciam fortemente o padrão temporal da atividade reprodutiva e a assembleia de larvas da L. grossidens e da P. platana na lagoa do Peri, Brasil.(AU)

Responses of water mite assemblages (Acari) to environmental parameters at irrigated rice cultivation fields and native lakes

Many studies have revealed that water mite communities can be affected by the physical and chemical parameters of the water. The similarity between the water ‘mite assemblages in local water bodies and in irrigated rice areas can be a way to measure the water conditions, enabling an assessment of the anthropic impact in the environment. The aim of this study was to evaluate the distribution of water mites in lakes and irrigated rice fields in south Brazil. To accomplish that we characterized the distinctive environments using physical and chemical variables such as pH, turbidity (NTU), water temperature (°C) and dissolved oxygen (mg/L), in order to verify the influence of these abiotic factors on the species composition of water mite communities; and to compare water mite abundance, richness and composition among different habitats. We assessed three native lakes and four sites with irrigated rice cultivation. Our results showed, for the first time in Brazil, strong correlations between the water mite fauna and turbidity. In addition, native lakes were richer and had greater mite abundance when compared with the irrigated rice areas.

Responses of water mite assemblages (Acari) to environmental parameters at irrigated rice cultivation fields and native lakes

Many studies have revealed that water mite communities can be affected by the physical and chemical parameters of the water. The similarity between the water ‘mite assemblages in local water bodies and in irrigated rice areas can be a way to measure the water conditions, enabling an assessment of the anthropic impact in the environment. The aim of this study was to evaluate the distribution of water mites in lakes and irrigated rice fields in south Brazil. To accomplish that we characterized the distinctive environments using physical and chemical variables such as pH, turbidity (NTU), water temperature (°C) and dissolved oxygen (mg/L), in order to verify the influence of these abiotic factors on the species composition of water mite communities; and to compare water mite abundance, richness and composition among different habitats. We assessed three native lakes and four sites with irrigated rice cultivation. Our results showed, for the first time in Brazil, strong correlations between the water mite fauna and turbidity. In addition, native lakes were richer and had greater mite abundance when compared with the irrigated rice areas.(AU)

Structure and dynamics of the phytoplankton community within a maturation pond in a semiarid region / Estrutura e dinâmica da comunidade fitoplanctônica de uma lagoa de maturação em região semiárida

Abstract In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha1.d1) and N:P 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology.(AU)

Resumo No nordeste do Brasil, as lagoas de estabilização são muito adequadas para o tratamento de águas residuárias por causa da disponibilidade relativamente grande de terra e das condições ambientais (por exemplo, altas temperaturas) favoráveis ao melhor desenvolvimento dos microorganismos. Entretanto, florações de cianobactérias potencialmente tóxicas podem afetar o uso dessas lagoas de tratamento, devido à consequente qualidade inferior do efluente. O objetivo deste estudo foi avaliar a dinâmica das comunidades de fitoplâncton e a ocorrência de cianobactérias em uma lagoa de maturação situada após duas lagoas em série. Temperatura, oxigênio dissolvido, pH, DBO, N e P foram medidos durante um período de quatro meses, durante o qual amostras foram coletadas na superfície e fundo em sete pontos de amostragem da lagoa. As comunidades de fitoplâncton das amostras coletadas foram também identificadas e classificadas utilizando-se um microscópio óptico convencional. Para avaliar os resultados utilizou-se a análise de variância e o teste de Tukey. Para as três divisões de fitoplâncton encontradas (Cyanophyta, Chlorophyta e Euglenophyta), não houve diferença significativa para as amostras de superfície e de fundo de um mesmo mês. Entretanto, ocorreu grande variação para as amostras dos diferentes meses; nos meses de abril e outubro houve uma predominância de Cyanophyta, ao passo que em setembro o predomínio na lagoa foi de Chlorophyta. Os fatores determinantes que favoreceram o predomínio de Cyanophyta foram a baixa carga orgânica superficial aplicada (entre 78 e 109 kg DBO.ha1.d1) e N:P 10. A presença de duas das espécies de Cyanophyta, Oscillatoria sp. e Microcystisaeruginosa, consideradas potencialmente tóxicas, indica que é necessária precaução quando se considera o destino final do efluente tratado e sugere a necessidade de avaliar os riscos e benefícios associados ao uso da tecnologia de tratamento.(AU)

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)

Aberturas del cordón de arena de la laguna costera Imboassica (Estado de Rio de Janeiro, Brazil) no alteran la abundancia de los peces comerciales / Openings of the sand bar in the coastal lagoon Imboassica (Rio de Janeiro State, Brazil) dont change the number of commercial fish individuals

La laguna Imboassica (estado de Rio de Janeiro), tuvo de 1993 a 2001 cuatro aberturas del cordón de arena que la separa del mar. Durante este período fueron realizadas 28 colectas de peces, siendo 55.6% de las especies de valor comercial clasificada en guildas funcionales como: residentes en lagunas costeras (RLC), marina-dependientes (MD), visitantes marinas (VM) y de agua dulce (D). La captura por unidad de esfuerzo (CPUE) de las especies de interés comercial en los períodos antes y después de las aberturas fue obtenida de acuerdo al tiempo y área de exposición de las redes. No hubo variaciones significativas en la abundancia de todas las guildas antes y después de las aberturas del cordón de arena. Fue observada una tendencia de aumento en la abundancia de individuos de las especies VM, RCL y MD en los períodos posteriores a abertura del cordón de arena. Cuando este permaneció cerrado por aproximadamente tres años, fueron realizadas 21 colectas de peces, con aumento en la abundancia de dulcicolas y disminución de otras guildas (VM, RCL y MD). La producción pesquera de la laguna Imboassica es considerada baja y varia por la abertura y cierre del cordón arenoso.(AU)

The coastal lagoon Imboassica (Rio de Janeiro State) had from 1993 to 2004 four openings of the sand bar that separates it from the ocean. During this period, 28 samples of fish fauna occurred; 55.6% with commercial value classified in functional guilds as: residents of coastal lagoons (RLC), marine dependent (MD), marine visitors (VM) and from freshwater (D). The catch per unit effort CPUE from the fish species with commercial value during the periods before and after the openings was availed according to exposure time and area of the gill nets. It was observed a growing trend of the individuals VM, RCL and MD with commercial interest during the periods after the openings of the sand bar. When the sand bar remained closed for at least three years, it was observed an increase on the abundance of freshwater fish, as a reduction on other guilds (VM, RCL and MD). The fish production in Imboassica lagoon is considered low and varies in function of the opening and closing of the sand bar.(AU)

Aberturas del cordón de arena de la laguna costera Imboassica (Estado de Rio de Janeiro, Brazil) no alteran la abundancia de los peces comerciales / Openings of the sand bar in the coastal lagoon Imboassica (Rio de Janeiro State, Brazil) dont change the number of commercial fish individuals

La laguna Imboassica (estado de Rio de Janeiro), tuvo de 1993 a 2001 cuatro aberturas del cordón de arena que la separa del mar. Durante este período fueron realizadas 28 colectas de peces, siendo 55.6% de las especies de valor comercial clasificada en guildas funcionales como: residentes en lagunas costeras (RLC), marina-dependientes (MD), visitantes marinas (VM) y de agua dulce (D). La captura por unidad de esfuerzo (CPUE) de las especies de interés comercial en los períodos antes y después de las aberturas fue obtenida de acuerdo al tiempo y área de exposición de las redes. No hubo variaciones significativas en la abundancia de todas las guildas antes y después de las aberturas del cordón de arena. Fue observada una tendencia de aumento en la abundancia de individuos de las especies VM, RCL y MD en los períodos posteriores a abertura del cordón de arena. Cuando este permaneció cerrado por aproximadamente tres años, fueron realizadas 21 colectas de peces, con aumento en la abundancia de dulcicolas y disminución de otras guildas (VM, RCL y MD). La producción pesquera de la laguna Imboassica es considerada baja y varia por la abertura y cierre del cordón arenoso.

The coastal lagoon Imboassica (Rio de Janeiro State) had from 1993 to 2004 four openings of the sand bar that separates it from the ocean. During this period, 28 samples of fish fauna occurred; 55.6% with commercial value classified in functional guilds as: residents of coastal lagoons (RLC), marine dependent (MD), marine visitors (VM) and from freshwater (D). The catch per unit effort CPUE from the fish species with commercial value during the periods before and after the openings was availed according to exposure time and area of the gill nets. It was observed a growing trend of the individuals VM, RCL and MD with commercial interest during the periods after the openings of the sand bar. When the sand bar remained closed for at least three years, it was observed an increase on the abundance of freshwater fish, as a reduction on other guilds (VM, RCL and MD). The fish production in Imboassica lagoon is considered low and varies in function of the opening and closing of the sand bar.

A protocol for measuring spatial variables in soft-sediment tide pools

We present a protocol for measuring spatial variables in large (>50 m2) soft-sediment tide pool. Secondarily, we present the fish capture efficiency of a sampling protocol that based on such spatial variables to calculate relative abundances. The area of the pool is estimated by summing areas of basic geometric forms; the depth, by taken representative measurements of the depth variability of each pool's sector, previously determined according to its perimeter; and the volume, by considering the pool as a prism. These procedures were a trade-off between the acquisition of reliable estimates and the minimization of both the cost of operating and the time spent in field. The fish sampling protocol is based on two con secutive stages: 1) two people search for fishes under structures (e.g., rocks and litters) on the pool and capture them with hand seines; 2) these structures are removed and then a beach-seine is hauled over the whole pool. Our method is cheaper than others and fast to operate considering the time in low tides. The method to sample fish is quite efficient resulting in a capture efficiency of 89%.

A protocol for measuring spatial variables in soft-sediment tide pools

We present a protocol for measuring spatial variables in large (>50 m2) soft-sediment tide pool. Secondarily, we present the fish capture efficiency of a sampling protocol that based on such spatial variables to calculate relative abundances. The area of the pool is estimated by summing areas of basic geometric forms; the depth, by taken representative measurements of the depth variability of each pool's sector, previously determined according to its perimeter; and the volume, by considering the pool as a prism. These procedures were a trade-off between the acquisition of reliable estimates and the minimization of both the cost of operating and the time spent in field. The fish sampling protocol is based on two con secutive stages: 1) two people search for fishes under structures (e.g., rocks and litters) on the pool and capture them with hand seines; 2) these structures are removed and then a beach-seine is hauled over the whole pool. Our method is cheaper than others and fast to operate considering the time in low tides. The method to sample fish is quite efficient resulting in a capture efficiency of 89%.(AU)

The influence of shoreline availability on the density and richness of Chironomid larvae in Neotropical floodplain lakes / Influência da disponibilidade de margem sobre a densidade e a riqueza de larvas de Chironomidae em lagoas de inundação neotropical

The shoreline development index was created for temperate lakes. However, Neotropical lakes have different geological formations. For example, the difference between the littoral and limnetic zones in Neotropical lakes is not as sharp as those in temperate one, due to their low depths. Here, we proposed a modification of the shoreline development index for tropical lakes. We applied the modified index in 27 floodplain lakes of the Upper Paraná River. We found significant and positive relationships between the modified index and the density and richness of chironomids. These results suggest that the higher the availability of margins the higher the density and richness of larvae. The littoral zone of some lakes is complex, with submersed or emergent macrophytes, as well as branches and leaves that provide a wealth of habitats in this region. Therefore, the larger littoral zone seems to be the main factor structuring the chironomid community. Therefore, the modified index is an important statistical tool to indicate lakes in which chironomid richness is high due to the higher availability of littoral zone.

Os índices de disponibilidade de margem em lagoas foram criados para a região temperada. No entanto, lagoas de ambientes temperados e neotropicais possuem diferentes formações geológicas. Por exemplo, a diferença entre a zona litorânea e a limnética não é tão acentuada em lagoas da região neotropical, devido às suas baixas profundidades. Neste estudo são propostas adaptações do índice de Hutchinson para lagoas tropicais. Aplicou-se este novo índice em 27 lagoas da planície aluvial do Alto Rio Paraná. O novo índice de disponibilidade de margens foi positivamente relacionado com a densidade e riqueza de Chironomidae. Estes resultados sugerem que quanto maior a disponibilidade de margens, maiores serão a densidade e a riqueza de larvas. A zona litorânea de algumas lagoas é complexa, com macrófitas submersas ou emergentes, além do substrato formado por galhos e folhiços que favorece a formação de diversos habitats nessa região. Portanto, a maior disponibilidade da zona litorânea parece ser o principal fator estruturador da comunidade de Chironomidae. Logo, o índice modificado demonstrou ser uma importante ferramenta estatística para indicar lagoas onde provavelmente encontram-se maiores valores de riqueza de Chironomidae, devido a maior disponibilidade em regiões litorâneas.

Presença do vírus da síndrome da mancha branca em crustáceos decápodes silvestres em lagoas costeiras no Sul do Brasil / Presence of the white spot syndrome virus (WSSV) in wild decapods crustaceans in coastal lagoons in southern Brazil

A presença do vírus da síndrome da mancha branca (em inglês WSSV) nas principais espécies de camarões, siris e caranguejos de cinco lagoas que recebem o efluente de fazendas afetadas pela enfermidade foi detectada por nested PCR, e inclusões virais nos camarões por histologia. Pela nested PCR encontrou-se a presença de WSSV em 13 de 16 (81,2 por cento) amostras de camarões da espécie Farfantepenaeus paulensis, em 13 de 14 (92,8 por cento) de Litopenaeus schmitti, em uma de duas de Farfantepenaeus brasiliensis (50 por cento), em 13 de 15 (86,6 por cento) de siri da espécie Callinectes danae e em 11 de 12 (91,6 por cento) de Callinectes sapidus, e não foi detectada no caranguejo Chasmagnathus granulata em 10 amostras. Inclusões características de WSSV foram observadas em três amostras histológicas de 50 (6,0 por cento) no epitélio gástrico e cuticular e nas brânquias de dois exemplares de F. paulensis e um de L. schmitti. É o primeiro relato da presença de WSSV em camarões L. schmitti e no siri C. danae silvestres. As principais espécies de camarões e siris dos ambientes de entorno das fazendas foram contaminadas pelo WSSV, constituindo-se em vetores potenciais do vírus.(AU)

The presence of white spot syndrome virus (WSSV) in the main species of shrimps, blue crabs, and burrowing crabs of five lagoons where shrimp farm effluents are discharged, was analyzed by nested PCR and the presence of virus inclusions in the shrimps was analyzed through histopathology. The nested PCR analysis indicated the presence of WSSV in 13 of 16 (81.2 percent) samples of the shrimp species of Farfantepenaeus paulensis, in 13 of 14 (92.8 percent) of Litopenaeus schmitti, in one of two of Farfantepenaeus brasiliensis (50 percent), in 13 of 15 (86.6 percent) of blue crab species of Callinectes danae and in 11 of 12 (91.6 percent) of Callinectes sapidus and none was detected in the 10 samples of the burrowing crab Chasmagnathus granulata. The inclusion characteristics of WSSV were observed in three samples of 50 (6.0 percent) in the gastric and cuticular epithelium and in the gills of two specimens of F. paulensis and one of L. schmitti. The presence of WSSV in L. schmitti wild shrimp and in the C. danae blue crab is reported for the first time in the present work. The results indicate that the main species of shrimps and blue crabs of the environment surrounding the farms were infected by WSSV, and they may be considered potential vectors of the virus.(AU)

Spatial and temporal distribution of fish eggs and larvae in a subtropical coastal lagoon, Santa Catarina State, Brazil

This study investigated the variation in abundance, distribution and composition of ichthyoplankton in a lagoon in southern Brazil through the year and at different stations within the lagoon. Ibiraquera Lagoon is a shallow coastal lagoon connected to the sea by a semi-permanent sandbar. Ichthyoplankton samples were collected monthly from December 2003 to December 2004, with a 200 µm mesh net using horizontal surface hauls. A colder, drier period was detected, contrasting with warm months during which salinity varied depending on rainfall and whether the sandbar was open or closed. The mean abundance of ichthyoplankton over the study period was 459.6 ± 76.2 (SE) eggs · 100 m-3 and 63.6 ± 7.9 (SE) larvae · 100 m-3, and they were present during all months. Significantly higher abundances of eggs and larvae were observed during warm months. The community was dominated by the family Engraulidae followed by Clupeidae, Gobiidae and Mugilidae. Engraulidae and Clupeidae were present throughout the year, with greater abundances in months with higher temperatures. Some coastal fish species spawn in Ibiraquera Lagoon, mainly near to the sandbar, demonstrating that the lagoon is a spawning area for coastal stock. We recommend the establishment of environmental procedures to promote the conservation of Ibiraquera Lagoon and its ichthyoplankton community.(AU)

A abundância, distribuição e composição do ictioplâncton foram investigadas em uma lagoa no sul do Brasil durante um ano e em diferentes estações dentro da lagoa. A lagoa de Ibiraquera é uma lagoa costeira rasa, conectada ao mar através de uma barra semi-permanente. As amostras de ictioplâncton foram coletadas mensalmente entre dezembro de 2003 e dezembro de 2004, com uma rede cônico-cilíndrica de 200 µm de malha em arrastos horizontais e de superfície. Foi detectado um período frio e seco em contraste aos meses quentes e com variação na salinidade em função das chuvas e da barra estar aberta ou fechada. A abundância média do ictioplâncton, durante o período de estudo, foi de 459,6 ± 76,2 (SE) ovos · 100 m-3 e 63,6 ± 7,9 (SE) larvas · 100 m-3, e ocorreram em todos os meses. As abundâncias de ovos e larvas foram significativamente maiores nos meses quentes. A comunidade foi dominada pela família Engraulidae seguida pelas famílias Clupeidae, Gobiidae e Mugilidae. As famílias Engraulidae e Clupeidae ocorreram principalmente nos meses com maiores temperaturas. Alguns peixes costeiros desovam dentro da lagoa, principalmente próximo a barra, evidenciando que a lagoa é uma área de desova para o estoque costeiro. Recomenda-se o estabelecimento de ações ambientais que promovam a conservação da lagoa de Ibiraquera e da comunidade ictioplanctônica.(AU)