Paranagua Estuarine Complex Research Articles

Mercury in trophic webs of estuaries in the southwest Atlantic Ocean

Anthropogenic activities have impacted the coastal region of Brazil. In the Paranaguá estuarine complex (PEC), Cananéia-Iguape estuarine-lagoon complex (CIELC), and Santos-São Vicente estuarine complex (SSVEC), such activities occur across differing scales. In these estuaries, the concentrations of mercury (Hg) and stable nitrogen isotopes (δ15N) were investigated in sediments and marine organisms including benthic macrofauna, fish and cetaceans. Hg bioconcentration occurred primarily in cetaceans, polychaetes and molluscs, and reflects the impact of anthropogenic activities in the regions studied (PEC and SSVEC > CIELC). Bioaccumulation occurred in most of the studied specimens, but biodilution of Hg was observed in the trophic webs of SSVEC and CIELC. Despite measuring lower Hg levels than in studies carried out in the northern hemisphere, the results highlight potential concerns for public and environmental health in these highly productive coastal regions in the southwestern Atlantic which are important for fishing and various economic activities.

Fishers’ ecological knowledge on the reproduction of fish and shrimp in a subtropical coastal ecosystem

Fishers’ ecological knowledge (FEK) has contributed to a better understanding about the reproduction of fishery resources, especially where biological data are scarce or unavailable. We analyzed FEK on the reproduction of five fishery resources in the Paranagua estuarine complex and adjacent coastal area, Brazil, including fishes (Genidens barbus, Centropomus parallelus, Chaetodipterus faber, Pseudobatos sp.) and shrimp (Litopenaeus schmitti). We also sought to compare FEK with biological data and investigate which characteristics (age, fish evisceration and fishers’ location) influence fishers' knowledge. We interviewed 132 artisanal fishers. FEK indicated reproductive peaks in the spring and summer for the fish species and in late winter and early spring for the shrimp. The maturation sizes according to FEK did not differ from sizes at first maturity (L50) as reported by biological studies for G. barbus and L. schmitti. Fishers’ residence sites and fish evisceration influenced more their knowledge related to species reproduction than age. Fishers showed a detailed ecological knowledge about some reproductive aspects, including size at first maturity of females, site of occurrence and reproductive peaks. Furthermore, fishers were able to identify sexual dimorphism, parental care and ovoviviparity. These results can be applied to improve fisheries management in the context of data poor fisheries.

Cumulative threats to juvenile green turtles in the coastal waters of southern and southeastern Brazil

Management of marine turtles at broad spatial scales is challenging due to the costs and the logistical feasibility of collecting ecological data and information on multiple threats at this scale. Spatially explicit assessments of the exposure of marine turtles to cumulative threats provides an alternative approach by identifying regions that are impacted by multiple threats at broad scales. To inform future management of juvenile green turtles, Chelonia mydas, off the southern and southeastern Brazilian coast we determined their cumulative exposure to five pertinent anthropogenic activities (marine traffic, port areas, and artisanal, trawl and gillnet fisheries). Information on the spatial distribution of juvenile green turtles was obtained by satellite tagging 14 wild-caught turtles in the Paranagua Estuarine Complex, off the Parana coast in southern Brazil and human activity information was obtained from various databases. This allowed us to identify the anthropogenic activities that provide the greatest risk to marine turtles (artisanal fisheries and marine traffic) and five “hotspot” threat areas that require prompt local management intervention to protect marine turtles in the region. These results can be used to inform on the ground efforts where further impact assessments and management interventions can be prioritized and undertaken.

First record of anomalous otoliths of Menticirrhus americanus in the South Atlantic

Sagitta otoliths are usually formed of calcium carbonate polymorphs as aragonite. The objective of this study was to verify which carbonate polymorph is predominant in the sagitta otolith of Menticirrhus americanus and check whether this pattern remains in otoliths with morphological alterations. Otoliths of M. americanus were obtained from five sites on the southeast‐south coast of Brazil (Sao Sebastiao (SS) 23°45′S–45°24′O, n = 29; Cananeia‐Iguape Estuarine Complex (CI) 25°02′S–47°54′O, n = 30; Paranagua Estuarine Complex (PEC) 25°28′S–48°20′O, n = 35; Itapoa (IT) 26°07′S–48°36′O, n = 31; Laguna (LA) 28°28′S–48°46′O, n = 13). The characterization of carbonate polymorphs of otoliths was performed through Raman spectroscopy, a photonic and non‐destructive technique that analyzes molecular vibrations induced by laser. We analyzed 138 pairs of M. americanus otoliths, of which eight otoliths from different pairs presented morphological alterations (SS n = 1, CEP n = 5, IT n = 1, LA n = 1). The Raman spectra show that normal otoliths, that is, without morphological alterations, presented only aragonite in their structure. Among the otoliths that presented morphological alterations, the Raman spectra allowed to identify in six otoliths the deposition of aragonite and in only two otoliths the deposition of vaterite (one specimen of the PEC and one of SS).

Age, growth, and reproductive biology of the Atlantic spadefish Chaetodipterus faber in southern Brazil

This is the first study to investigate the age, growth and reproductive biology of the Atlantic spadefish Chaetodipterus faber in southern Brazil. A total of 625 individuals [total length (TL) ranging from 7 mm to 510 mm] were sampled at the Paranagua Estuarine Complex (PEC) and adjacent coastal areas over a year (August 2015 to July 2016). Age estimation based on sagittal otolith cross section showed that C. faber has a 17-year longevity close to its southern distributional limit, two times greater than previously reported from the North Atlantic Ocean. Sexual growth dimorphism was not evident as the male:female sex ratio was 1:1.17. The species displayed asymptotic growth. Fitted von Bertalanffy growth function estimates for all individuals were L∞ = 508.81 mm, k = 0.22 year−1, and t0 = -0.05 year. The histological gonadal examination and gonado-somatic index indicated that C. faber is a batch spawner with a main reproduction period from October to January in subtropical latitudes at 25°S. Postovulatory follicles were often recorded in the ovaries of spawning capable individuals indicating a high frequency of spawns over the reproductive period. The data also suggest that estuaries are important reproductive areas for this species that most likely exhibits a seasonal movement for spawning aggregation purposes. Females mature approximately 0.5 years later than males and are capable of spawning just prior to two years old. Fishery closures during the spawning season and fishing size restrictions should be used to manage the C. faber stock in southern Brazil. The effects of current harvest levels are unknown and warrant further investigation to assist management decisions.

Using Ostrom's principles to assess institutional dynamics of conservation: Lessons from a marine protected area in Brazil

The success of protected areas as a management tool for biodiversity conservation remains as a challenge, and broader approaches for protected area management have been proposed. Considering biodiversity conservation as an issue of the commons and within the realm of social-ecological systems is a promising alternative. In Brazil protected areas are under a State management regime, ruled by the National System of Conservation Units. The Ecological Station of Guaraqueçaba (ESG) is a no-take protected area located in the Paranagua Estuarine Complex, surrounded by traditional communities. In this article, Ostrom's design principles were adapted to assess the institutional dynamics of this protected area management, during two periods. Research methods included semi-structured interviews, participant observation and document analysis. During the first period, management actions were oriented to prevent the conversion of forest areas into anthropic occupations. The second period originated in 2000 with the creation of the National System of Conservation Units, which established more precise management tools and mechanisms for participatory decision making. In both periods there was low fulfillment of Ostrom's principles. The main changes over time were the creation of the ESG management council as a conflict-resolution mechanism, and an increase in the recognition of the rights of local communities. Yet, only three of the eight principles are totally present in the current institutional arrangement (well-defined boundaries, conflict-resolution mechanisms, and minimal recognition of rights). The results suggest a not robust institutional arrangement in terms of commons sustainable management.

Use of otolith microchemistry as habitat indicator of Anchoa tricolor (Spix and Agassiz, 1829) in a subtropical estuary

The objective of the present study was to evaluate the use of sagitta otolith microchemistry (Sr:Ca, Ba:Ca ratios) as habitat indicator of Anchoa tricolor between the estuary and the adjacent continental shelf. We analyzed 162 specimens of A. tricolor in the Paranagua Estuarine Complex (Brazil), and salinity and rainfall data. The biological and environmental data were grouped into sectors (internal, intermediate, and external) and periods (early and late wet, and dry periods). The concentrations of Ca, Ba and Sr were determined using an ICP-OES. The Sr:Ca ratio indicated the existence of two groups, probably from different origins, that use the estuary at the same time, but occupying different sectors of the estuary. The Ba:Ca ratio did not differentiate the groups as to the use of estuary, but rather revealed low values, suggesting that this species does not use freshwater environments. However, this ratio showed a high variation in the wet period, indicating a greater availability of barium in the estuarine regions affected by the river discharge. Considering our results, it is possible to classify A . tricolor as an estuarine migrant species. Also, the Sr:Ca and Ba:Ca ratios can be indicative of the habitat use in a subtropical estuary.

Aspectos reprodutivos de mexilhões (Bivalvia, Mollusca) no complexo estuarino de Paranaguá, Paraná, Brasil

Este trabalho teve como finalidade estudar o perí­­odo reprodutivo dos mariscos (Mytella guyanensis e Mytella charruana) no Complexo Estuarino de Paranaguá (CEP). Foram coletados mensalmente 30 indiví­­duos adultos de cada espécie durante agosto de 1999 a julho de 2000. Os indiví­­duos foram mensurados, pesados e abertos mecanicamente pela secção dos músculos adutores. Posteriormente foram identificados o sexo e o estágio reprodutivo e calculados os í­­ndices de condição (IC) e o rendimento da carne (R). Os dados do IC indicaram média de 13,25 % (± 6,95) para M. guyanensis e de 17,65 % (± 12,11) para M. charruana. Para o R, observou-se média de 43,68 % (± 10,15) para M. guyanensis e de 51, 22 % 28 (± 8,64) para M. charruana. Os estudos da reprodução permitem concluir que a eliminação de gametas ocorre parcialmente para as duas espécies, com dois perí­­odos mais elevados de desova no ano.

Ictiofauna acompanhante da pesca de arrasto para embarcações acima de 45 hp no litoral do Paraná, Brasil

A pesca de arrasto de camarões é considerada muito impactante aos sistemas bentônicos por ser pouco seletiva. O objetivo do presente trabalho foi caracterizar a ictiofauna acompanhante da pesca de arrasto das embarcações com potência acima de 45 HP. Foram realizadas amostragens mensais, entre agosto de 2000 e julho de 2001 para barco e agosto de 2004 e julho de 2005 para bote no litoral do Paraná. Foram capturados, com barco e bote, 45.277 e 57.387 peixes, respectivamente. Com ambas embarcações foram capturaram 99 táxons. A famí­­lia Sciaenidae foi a mais representativa em número de espécies e indiví­­duos. Houve diferenças na ictiofauna entre as estações do ano e entre as áreas ao sul e ao norte da desembocadura do Complexo Estuarino de Paranaguá tanto para barco como para bote. As diferentes frotas atuam sobre o mesmo recurso, mas incidem de maneira distinta com relação í­Â riqueza de espécies e abundí­¢ncia ictiofauna acompanhante e medidas de gestão, como a implementação de dispositivos de redução da captura acidental, devem levar em consideração as caracterí­­sticas não somente da embarcação mas também do petrecho de pesca utilizado.

Vulnerability Among Fishers in Southern Brazil and its Relation to Marine Protected Areas in a Scenario of Declining Fisheries

Vulnerability of small-scale fishers in the north coast of Paraná State, Southern Brazil, has been increasing due to a decline in catches and general problems of access to and management of natural resources, associated with biodiversity conservation policies. The predicted effects of climate change will represent an additional source of disturbance on local livelihoods. This study aimed to describe vulnerability of fishers and their adaptation strategies to ongoing reductions in catches, considered an analogue of possible responses to expected effects of climate change, and to evaluate the influence of no-take protected areas on them. Interviews were applied to 213 households, in 9 villages from Guaraqueçaba, in the Paranaguá Estuarine Complex. Results show that vulnerability varies in different spatial levels, mainly due to differences in the reliance on fisheries as a source of income, and in distribution of physical and social capital. Protected areas, if not adequately managed, can have a double negative effect on more vulnerable households, by restricting their access to mangrove resources in the present, and by limiting the viability of their favoured adaptation strategy for the future. These results are potentially useful for the development of biodiversity conservation and fisheries management actions adequate to the local level, and that contribute to reduce inequality and build resilience of fishers and the coastal ecosystems they rely on, in a scenario of declining fisheries and climate change.

Considerations Regarding Sedimentation Rates along the E-W Axis of the Paranaguá Estuarine Complex, Brazil: A Bathymetric Approach

ABSTRACT Cattani, P.E. and Lamour, M.R., 2016. Considerations regarding sedimentation rates along the E-W axis of the Paranagua Estuarine Complex, Brazil: A bathymetric approach. The sediment dynamics in coastal regions are a result of the coexistence of fluvial, estuarine, deltaic, and shelf depositional environments, as well as the relation among the processes of sediment transport. The Paranagua Estuarine Complex (PEC) presents different characteristics along its E-W axis, containing areas of port activity. The aim of this study was to identify critical areas of estuarine sedimentary infill and determine their rates and relationships regarding the estuarine environment features. This study employed 38 bathymetric surveys conducted between 1999 and 2008 arranged sequentially from the head of the estuary to the inner continental shelf. Initially, these surveys were grouped chronologically and according to their areas of overlap. Later, they were divided according to grain size and short-term hydrodynamic...

<b>Habitat use by <i>Atherinella brasiliensis</i> (Quoy & Gaimard, 1825) in intertidal zones of a subtropical estuary, Brazil

Habitat use is different along the ontogenetic development of some species and may be influenced by environmental parameters. This study described the interaction of Atherinella brasiliensis caught in intertidal areas of the Paranagua Estuarine Complex with environmental parameters. We caught 10024 individuals between August 2010 and July 2011, with total mean length of 44.32 mm (SD ± 25.37 mm), variation range between 12 and 142 mm, and weight between 0.01 and 73 g, averaging 1.35 g (SD ± 2.66 g) and ages estimated between < 1 and 22 months. Significant differences were detected between sectors and periods for number of individuals and weight at capture, with higher mean values in the mean sector during the rainy period. The spatial and temporal distribution of ages was statistically different, individuals between < 1 and 3 months were more abundant in the sector 2 during the rainy period, and individuals older than 7 months were evenly distributed throughout the sampling area, and with higher mean abundance at the beginning and end of the dry period. Environmental variables that most influenced the distribution of age classes were temperature and salinity.

A case study of sediment transport in the Paranagua Estuary Complex in Brazil

This paper presents transport of a mixture of cohesive sediments and sand in the Paranagua Estuarine Complex in the south of Brazil. The estuary houses a navigation channel from the Atlantic Ocean to a busy harbour. The channel requires frequent dredging owing to sediment deposition to maintain navigable depth for vessels. A three-dimensional process-based model for sediment transport coupled with wave-current models based on the Delft3D modelling system is constructed for the estuary. Extensive field data concerning current velocity, water level, salinity and suspended sediment concentration were collected. The flow model that is necessary to run the sediment transport model was calibrated and validated using field measurements. In this paper only the results concerning the sediment motion are presented. Calibration and validation of the numerical model show that the results of sediment transport represent the field conditions well. Additional support for the validity of the computed results is provided by field data pertaining to bathymetry acquired in 2005 and 2006. The present study gives insight into the motion of cohesive sediments and the morphological behaviour of the estuary, and should help operators maintain the channel for navigation.

Biogeochemical Behavior of Arsenic Species at Paranaguá Estuarine Complex, Southern Brazil

The behavior and dynamics of arsenic at Ilha do Mel, Guaraquecaba, and Paranagua, located in the Paranagua Estuarine Complex, Brazil, were investigated in this work. Samples were collected in March, September, and December of 2005. With respect to arsenic behavior, the total concentrations were higher for Paranagua (22.5 ± 2.5 μg L−1) on average, followed by the samples of Guaraquecaba (14.4 ± 3.2 μg L−1) and Ilha do Mel (8.7 ± 1.1 μg L−1). The concentrations found in this work were consistently greater when compared to other estuaries. The results can be attributed to geological factors. Nevertheless, it was also possible to realize that higher concentrations were found in Paranagua, the more impacted environment. These results represent a strong indication that human activities in the area contribute to the enrichment of the estuary with this metalloid. Arsenic was mainly present in the dissolved phase, which corresponded to more than 70% of the total concentration. This behavior can represent a greater residence time of this metalloid in the water column. The marine phytoplankton presence was decisive in dictating the distribution of As in the waters of Paranagua estuary. Organic species, which are considered the less toxic, were found in higher concentrations in the eutrophic areas such as Guaraquecaba and Paranagua. This was a typical behavior during the summer probably due to higher biological activity.

O sensoriamento remoto como ferramenta para determinação de batimetria de baixios na Baía das Laranjeiras, Paranaguá - PR

Baixios representam riscos a navegação no interior dos estuários. Portanto, devem ser bem delineados e tais informações devem ser freqüentemente atualizadas. Métodos hidrográficos tradicionais têm dificuldade em cobrir áreas rasas devido sua extensão e relevo. Uma alternativa é o uso de imagens de satélites para mapear essas áreas, com as vantagens de baixo custo e rápido resultado. No setor norte do Complexo Estuarino de Paranaguá o último levantamento batimétrico foi realizado na década de 50 e um novo mapeamento destas áreas, mesmo sem a acurácia das cartas náuticas, é de utilidade para o planejamento de estudos, modelagem ambiental e navegação de pequenas embarcações. Este estudo teve o objetivo de avaliar o potencial de gerar mapa batimétrico das áreas rasas da Baía das Laranjeiras, através do sensoriamento remoto. A aplicação deste método é fácil e mostrou-se bastante útil em regiões onde não existem dados batimétricos ou estes precisam ser atualizados. O mapa obtido é bastante fiel dentro dos limites batimétricos que se pretende, entre 0,36 e 4,5 m de profundidade, principalmente considerando que 75% do complexo estuarino possui profundidade inferior a 5 m.

PADRÕES DE TRANSPORTE DE SEDIMENTOS BASEADO EM TRÊS PROGRAMAS GERADORES DE VETORES DE TENDÊNCIAS DE TRANSPORTE A PARTIR DE PARÂMETROS GRANULOMÉTRICOS NA PORÇÃO SUL DO DELTA DE DESEMBOCADURA DO COMPLEXO ESTUARINO DE PARANAGUÁ - SUL DO BRASIL

Este trabalho apresenta os resultados da aplicação dos programas de geração de vetores de tendência de transporte de sedimentos GSTA, GSTAST e TRANSVEC, baseados em parâmetros granulométricos (média granulométrica, desvio padrão e assimetria) de sedimentos da porção sul do delta de desembocadura do Complexo Estuarino de Paranaguá. O transporte preferencial na área estudada dá-se de sudoeste para nordeste, regido pela passagem de sistemas frontais provenientes de sul que transferem grandes quantidades de energia ao sistema, havendo o empilhamento destes sedimentos causado pelo efeito “molhe hidráulico” das correntes predominantes de vazante na desembocadura sul do estuário, tornando-a mais pronunciada que a parte norte. Este fenômeno possibilita o desenvolvimento de um extenso banco de areia, denominado banco da Galheta, com profundidades variando entre 1,5 a 5,0 metros na região, onde as ondas quebram causando o transporte em direção à costa, evidenciado por esporões que migram embocadura adentro. Após a análise dos resultados, observa-se que os vetores gerados pelo programa GSTA encaixam-se perfeitamente na batimetria da área. Estão de acordo com o esperado na parte sul e central da área, mas não parecem bons nos setores NE e NW da área. O programa TRANSVEC identifica muito bem o direcionamento do transporte para o canal que margeia o delta e também uma tendência do canal marginal de exportar sedimentos durante maré vazante na parte NW da área. Os vetores indicam transporte preferencial para SW, o que contraria todas as observações para a área em questão. O programa que melhor satisfaz as tendências esperadas é o GSTAST. O teste de significância para os vetores, bem como a geração de vetores adicionais empíricos que são utilizados no processo de filtragem do GSTAST, funcionou a contento neste caso em particular. Os vetores a leste da área refletem o transporte de material pelas ondas quebrando no banco da Galheta, os vetores centrais mostram o empilhamento da deriva de sul para norte sobre o delta de desembocadura e os vetores a oeste da área refletem a deflexão da deriva litorânea próximo à súbita queda na profundidade causada pela presença do delta.