RESUMO

In the presence of vessels, dolphins have been found to change their habitat, behavior, group composition and whistle repertoire. The modification of the whistle parameters is generally considered to be a response to the engine noise. Little is known about the impact of the physical presence of vessels on dolphin acoustics. Whistle parameters of the coastal and oceanic ecotypes of common bottlenose dolphins in La Paz Bay, Mexico, were measured after the approach of the research vessel and its engine shutdown. Recordings of 10 min were made immediately after turning off the engine. For analysis, these recordings were divided from minute 0 to minute 5, and from minute 5:01 to minute 10. The whistles of the oceanic ecotype showed higher maximum, minimum and peak frequency in the second time interval compared to the first one. The whistle rate decreased in the second time interval. The whistles of the coastal ecotype showed no difference between the two time intervals. The physical presence of the research vessel could have induced a change in the whistle parameters of the oceanic dolphins until habituation to the vessel disturbance. The oceanic ecotype could increase the whistle rate and decrease the whistle frequencies to maintain acoustic contact more frequently and for longer distances. The coastal ecotype, showing no significant changes in the whistle parameters, could be more habituated to the presence of vessels and display a higher tolerance.

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Pollution is a major worldwide problem that is increasing with urban growth, mainly along coastal areas. Pollution is often worse, governance is poorer and managerial strategies to improve environmental quality are less advanced in developing than developed countries. Here, we present an overview of the current scientific knowledge of the impacts of contamination on the biota of coastal ecosystems of Brazil and evaluate the scientific challenges to provide baseline information for local managerial purposes. We compiled data from 323 peer-reviewed published papers from the extensive Brazilian coast. We critically evaluated the produced knowledge (target contaminants, sources, ecosystems, taxa, response variables) and the science behind it (rigour and setting) within its socioenvironmental context (land occupation, use of the coast, sanitation status, contamination history). Research was driven largely by environmental outcomes of industrial development with a focus on the single effects of metals on the biota. The current knowledge derives mainly from laboratory manipulative experiments or from correlative field studies of changes in the biota with varying levels of contamination. Of these, 70% had problems in their experimental design. Environmental impacts have mainly been assessed using standard indicators of populations, mostly in ecotoxicological studies. Benthic assemblages have mostly been studied using structural indicators in field studies. Future assessments of impacts should expand research to more taxonomic groups and ecosystem compartments, adding combined functional and structural responses. Furthermore, further investigations need to consider the interactive effects of contaminants and other environmental stressors. By doing so, researchers would deliver more robust and effective results to solve problems of pollution.

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Intense human use and high construction density in coastal areas are stressors to sandy beaches. Pollution by marine debris is a major problem on beaches worldwide. This study pioneered an assessment of marine debris characterization over time on beaches with different levels of access. In two periods and seasons, marine debris was sampled on nine sandy beaches of Rio de Janeiro, grouped by levels of access. The general marine debris density has decreased over time, accompanied by an improvement in public cleaning mechanisms. The most important predictor for the majority of marine debris items is related to accessibility; beaches with restricted access showed a reduction in the abundance of most items. High marine debris densities, even on beaches with restricted access, showed that all evaluated beaches can be sinks for marine debris circulating in marine waters. Beach cleaning strategy improvements will be inefficient unless integrated marine debris management is implemented.

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Documenting recent extinction events against the backdrop of increasing human-induced environmental pressure is complicated by the lack of historical and subfossil evidence for most parts of the world. This paucity of data renders it particularly difficult to evaluate the human impact on fragile environments, such as small islands, that may have been heavily altered by historical human exploitation. Here we describe a new species of an extinct Leiocephalus lizard from Guadeloupe, Leiocephalus roquetus sp. nov. based on recent discoveries of both a previously undocumented historically taxidermy specimen and of a large assemblage of subfossil bone remains from La Désirade Island. This new species presents a primitive morphology compared to all extant species of its genus and provides evidence for the past existence of a Lesser Antillean clade of Leiocephalus lizards that was completely wiped out in the centuries following the European colonization of these islands. Our study demonstrates how paleontological approaches can help to better understand the history of human environmental impact as well as the degree of degradation of modern ecosystems.

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The northeastern region of Brazil is the most densely populated and biodiverse semi-arid regions of the planet. Effects of the natural climate variability and colonization on the landscape have been described since the beginning of the 16th century but little is known about their effects on natural resources. Climate projections predict temperatures above 40 °C and an increase in the number and duration of droughts at the end of the 21st century with strong societal impacts. Here, we analyze the influence of public policies, human activities and natural climate variability on the environment over the last 60 years. Our study is based on sedimentological and environmental reconstructions from two sediment cores collected in two dam lakes on the river Acaraú in the State of Ceará. Multiproxy analyses of both cores (inorganic geochemistry, pollen, charcoal, remote sensing) at an annual resolution showed that 1) at interannual scale composition and distribution of the dry forest (known as Caatinga) were not affected by the alternance of drought and high moisture episodes; 2) at decadal scale human activities such as agriculture were reflected by changes in vegetation cover and fishery by progressive changes in lake trophic status; 3) public policies were able to promote changes in the landscape e.g., land colonization with the regression of the dry forest and irrigation plan able to amplify the deforestation and change the floristic composition. Thanks to paleo-science approach, our environmental diagnosis should help future decision-making and provide guidelines for preservation of resources and wellbeing of the inhabitants.

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Global mining activities in Latin America have increased exponentially over the last decade. The present study aims to assess the historical impact of Artisanal and Small-scale Gold Mining activities (ASGM) in the Department of Antioquia, Colombia, a region characterized by increased mining development over the past century. Historical trends of heavy metals (i.e., Ag, Cr, Cu, Hg, Ni, Pb, and Zn) were reconstructed for the past century in a tropical wetland near the mining district. Results indicate that local mining operations did not have a significant influence in the area until the mid-20th century when metal concentrations began to increase and exceeded background values. The significant increase in both sediment accumulation rates and total organic carbon (TOC) content during the 1920s reflects the deforestation of the area due to the diversification of the economy (e.g. coffee cultivation, mining or animal husbandry). Both concentrations and accumulation rates of metals increased exponentially after the 1980s as a consequence of the reactivation of alluvial gold exploitation, reaching values that exceeded up to 2-5 times the background levels. The historical metal trends in sediments from Las Palmas wetland reflected the historical socio-economic development in Antioquia and can be used as a good proxy for evaluating anthropogenic impacts in this region.

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Abstract: Hydropower constructions cause severe disturbances to biodiversity. Arboreal plants die after flooding; however, they expose their emerged branches (also called paliteiros) as a new habitat for animals and plants. Nothing is known about how paliteiros influence the presence of aquatic birds. This study verified which species of birds use the paliteiros, what are their behaviors and probably consequences to ecological processes. In November 2018, we sampled 5 km of paliteiros recording perched birds and their behaviors in the Três Marias dam, a 1040 km2 flooded area in southeastern Brazil. In total, 5.4% of paliteiros were used by 14 bird species. The Neotropic Cormorant Nannopterum brasilianus (Gmelin, 1789) was the most frequent species. Birds mainly preened feathers; they also rested (with no apparent activity), defecated, hunted, fed, vocalized and drank water. Attention must be focused to some behaviors such as resting and defecation, which may influence long-term ecological processes (e.g., incorporating additional organic matter and changing aquatic community) in the dam.

Resumo: Construções de hidrelétricas causam severos distúrbios à biodiversidade. Após a inundação de grandes áreas as plantas arbóreas morrem, apesar disso, elas deixam expostos seus galhos emersos (também chamados de paliteiros) criando um novo hábitat para animais e plantas. Nada se sabe sobre como os paliteiros influenciam a presença de aves aquáticas. Este estudo verificou quais espécies de aves utilizam os paliteiros, quais comportamentos elas exibem e suas prováveis consequências para processos ecológicos. Em novembro de 2018 foram amostrados 5 km de paliteiros, as aves empoleiradas nestas estruturas e seus comportamentos na represa de Três Marias, uma área inundada de 1040 km2 no sudeste do Brasil. Ao total, 5.4% das árvores mortas foram utilizadas por 14 espécies de aves. O biguá Nannopterum brasilianus (Gmelin, 1789) foi a espécie mais frequente nos paliteiros. As aves frequentemente limparam as penas, descansaram (sem nenhuma atividade aparente), defecaram, caçaram, se alimentaram, vocalizaram e beberam água. Mais atenção deve ser focada em alguns comportamentos das aves tais como o descanso seguido de defecação que podem influenciar processos ecológicos a longo prazo (p. ex., a incorporação de matéria orgânica e mudança de comunidade aquática) na represa.

RESUMO

Sandy beaches pollution by marine debris imposes arguably threats for the biodiversity, but interaction of beach bioindicators (e.g., ghost crabs) with debris has been rarely assessed. We aimed to test whether the Atlantic ghost crab Ocypode quadrata (Fabricius, 1787) misidentifies marine debris as food sources. Cigarette butts, straws, popsicle sticks, paper napkins and styrofoams were mixed into solutions with odour of natural and industrialized food. The debris were placed around burrows on beaches with distinct human pressures (low, medium and high-impact). The species interacted with marine debris more frequently in situations of lower human impact, lower prey abundance and larger burrow diameter. These results indicate that in areas with low prey availability and larger individuals, interactions between ghost crabs and debris left by beach visitors and/or transported by winds and currents to low-impact beaches are more likely to occur, mainly near to urbanized areas.

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Law enforcement is widely regarded as a cornerstone to effective natural resource management. Practical guidelines for the optimal use of enforcement measures are lacking particularly in areas protected under sustainable and/or mixed use management regimes and where legal institution are weak. Focusing on the yellow-spotted river turtles (Podocnemis unifilis) along 33 km of river that runs between two sustainable-use reserves in the Brazilian Amazon as an illustrative example, we show that two years of patrols to enforce lawful protection regulations had no effect on nest harvesting. In contrast, during one year when community-based management approaches were enacted harvest levels dropped nearly threefold to a rate (26%) that is likely sufficient for river turtle population recovery. Our findings support previous studies that show how community participation, if appropriately implemented, can facilitate effective natural resource management where law enforcement is limited or ineffective.

RESUMO

Abstract Aquatic environments face a variety of threats in the Hondo River basin, Southeastern Yucatán Peninsula. Some of these impacts, like pollution by pesticides, may depend on land use and cover. Our objective was to assess the effect of land use/cover using a previously published index of biotic integrity (IBI), based on fishes and designed for shallow streams in the Hondo River basin. Our hypothesis was that land uses that cause deforestation and pollution, such as urbanization, cattle breeding, or sugar cane fields, would be reflected in low IBI values, at least at some spatial scales. The 23 sites originally used in 2008-2009 to estimate by electrofishing the relative abundance and other characteristics of selected fish species and guilds to construct the IBI, were revisited in February 2010, to validate by direct inspection the type of land use/cover suggested by landscape information in digital databases. We analyzed the effect of seven types of land use/cover (agriculture, pasture, human settlements, water bodies, wetlands, forest, and secondary vegetation) on the IBI values, at four spatial scales, i.e., the percent of every land use/cover at progressively larger circles (125, 250, 500, and 1 000 m diameter) centered on the water body where the IBI value was measured. Correlations were established among the percent land/use cover by scale around 23 sites, and with their corresponding IBI values. Then, Student's t tests were calculated to examine significant differences in land use/cover between groups of localities above and below the median IBI value, and Mann-Whitney's U tests were applied to compare IBI values between localities with andwithout a given landscape cover. Agriculture, human settlements, and secondary vegetation correlated negatively with the IBI; forests positively. Differences were significant (p<0.05) for forest (higher in sites with higher IBI values) and human settlements (lower in sites with higher IBI). Of all the landscape categories located in the Hondo River basin, with the exception of pasture, those of anthropogenic origin tended to be detrimental to aquatic biotic integrity.

Resumen Los ambientes acuáticos en la cuenca del río Hondo, sureste de la península de Yucatán, enfrentan diversas amenazas. Algunos de estos impactos, e.g. contaminación por plaguicidas, pueden depender del uso de suelo o cobertura. El objetivo fue evaluar el efecto del uso del suelo/cobertura sobre un índice biótico de integridad (IBI) basado en peces, publicado previamente, diseñado para arroyos someros en esta cuenca. La hipótesis era que los usos del suelo que involucran deforestación y contaminación, entre ellos urbanización, ganadería o cultivo de caña de azúcar, se verían reflejados en valores bajos del IBI, por lo menos a ciertas escalas espaciales. Los 23 sitios usados originalmente para estimar por electropesca la abundancia relativa y otras características de especies y gremios selectos de peces, para construir el IBI, fueron visitados de nuevo en febrero 2010 para validar por inspección directa el tipo de uso del suelo/cobertura sugerido por la información de paisaje en bases de datos digitales. Se analizó el efecto de siete tipos de uso del suelo/cobertura (agricultura, ganadería, asentamientos humanos, cuerpos de agua, humedales, bosque y vegetación secundaria) sobre los valores del IBI, a cuatro escalas espaciales, i.e., el porcentaje de cada uso del suelo/cobertura en círculos progresivamente mayores (125, 250, 500 y 1 000 m de diámetro) centrados en el cuerpo de agua donde se midió el valor del IBI. Los porcentajes de uso del suelo/cobertura por escala se correlacionaron entre sí y con los valores correspondientes del IBI para explorar su asociación; luego, mediante pruebas t de Student se buscaron diferencias significativas en cobertura entre grupos de localidades por encima y por debajo del valor mediano del IBI, así como pruebas U de Mann-Whitney para comparar valores del IBI entre localidades con o sin una cobertura dada. La agricultura, asentamientos humanos y vegetación secundaria mostraron una relación negativa con el IBI, lo cual sugiere un impacto de las actividades humanas sobre la salud de los ecosistemas acuáticos. Las diferencias fueron significativas para el bosque (mayor en sitios con mejor integridad acuática) y los asentamientos humanos (menor en sitios con mayor valor del IBI). De todas las clases paisajísticas en la cuenca del río Hondo, las de origen antrópico, excepto los pastizales para ganadería, tendieron a ser perjudiciales para la integridad biótica acuática.

RESUMO

The interconnected nature of surface and subsurface karst environments allows easy disturbance to their aquifers and specialized ecosystems from anthropogenic impacts. The karst disturbance index is a holistic tool used to measure disturbance to karst environments and has been applied and refined through studies in Florida and Italy, among others. Through these applications, the karst disturbance index has evolved into two commonly used methods of application; yet, the karst disturbance index is still susceptible to evaluation and modification for application in other areas around the world. The geographically isolated and highly vulnerable municipality of Arecibo, Puerto Rico's karst area provides an opportunity to test the usefulness and validity of the karst disturbance index in an island setting and to compare and further refine the application of the original and modified methods. This study found the both methods of karst disturbance index application resulted in high disturbance scores (Original Method 0.54 and Modified Method 0.69, respectively) and uncovered multiple considerations for the improvement of the karst disturbance index. An evaluation of multiple methods together in an island setting also resulted in the need for adding additional indicators, including Mogote Removal and Coastal Karst. Collectively, the results provide a holistic approach to using the karst disturbance index in an island karst setting and suggest a modified method by which scaling and weighting may compensate for the difference between the original and modified method scores and allow interested stakeholders to evaluate disturbance regardless of his or her level of expertise.

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The aim of the present study was to explore the diversity and describe the spatial distribution of Calliphoridae and Sarcophagidae along an urbanization gradient in the Iberá Wetlands. The flies were collected at 18 sampling points, three per site. In total, 3,318 flies were collected (3,077 blow flies and 241 flesh flies), distributed in 13 genera and 33 species. Calliphoridae was the most abundant, comprised 92.74% of all adult flies. Chrysomya albiceps (Wiedemann), Cochliomyia macellaria (F.), Chrysomya megacephala (F.), and Chrysomya putoria (Wiedemann) were the most abundant species, representing 82.21% of the total sample. The genus Oxysarcodexia Townsend was the most diverse with 10 species represented. The abundance of exotic species represents 62.85% of the total sample, showing a reduction toward less disturbed sites. The results of this study indicated that sites with intermediate impact had higher diversity than those where the disturbances are high or absent. Our findings provide the first assessment of Calliphoridae and Sarcophagidae diversity in the area of the Iberá Wetlands.

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Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

Resumo Riachos podem exibir diferenças na estrutura das comunidades de invertebrados à deriva, o que pode ser um reflexo da variação nos fatores ambientais, capazes de se alterar em condições de intervenções antrópicas. O objetivo deste trabalho foi analisar a composição, diversidade e abundância de insetos à deriva em dois riachos neotropicais sob diferentes usos do solo, além de identificar os fatores ambientais intervenientes na determinação de tais padrões. Foram registrados 54 táxons de insetos aquáticos nos riachos urbano e rural. Os resultados evidenciaram diferenças significativas na composição de espécies, devido à substituição de espécies especialistas por espécies generalistas no riacho urbano. Maior diversidade de táxons foi registrada no riacho rural, com altos níveis de oxigênio dissolvido e elevado fluxo hídrico, que favoreceram a ocorrência de grupos sensíveis a perturbações ambientais, como táxons das ordens Ephemeroptera, Plecoptera, Trichoptera e Coleoptera, que vivem principalmente em águas limpas e bem oxigenadas. Por outro lado, maior densidade de insetos a deriva, especialmente Chironomidae, foi observada no riacho urbano, onde foram registrados elevados valores de pH, condutividade elétrica e nitrogênio. Estas larvas são capazes de explorar uma vasta gama de condições ambientais, consequência da sua grande capacidade de adaptação fisiológica. Apesar de ter encontrado os padrões esperados, não foram contatadas diferenças significativas na diversidade e abundância de espécies entre os riachos. Assim, a composição de espécies pode ser considerada como melhor preditora de impactos sobre a comunidade de insetos à deriva.

Assuntos

RESUMO

Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.(AU)

Riachos podem exibir diferenças na estrutura das comunidades de invertebrados à deriva, o que pode ser um reflexo da variação nos fatores ambientais, capazes de se alterar em condições de intervenções antrópicas. O objetivo deste trabalho foi analisar a composição, diversidade e abundância de insetos à deriva em dois riachos neotropicais sob diferentes usos do solo, além de identificar os fatores ambientais intervenientes na determinação de tais padrões. Foram registrados 54 táxons de insetos aquáticos nos riachos urbano e rural. Os resultados evidenciaram diferenças significativas na composição de espécies, devido à substituição de espécies especialistas por espécies generalistas no riacho urbano. Maior diversidade de táxons foi registrada no riacho rural, com altos níveis de oxigênio dissolvido e elevado fluxo hídrico, que favoreceram a ocorrência de grupos sensíveis a perturbações ambientais, como táxons das ordens Ephemeroptera, Plecoptera, Trichoptera e Coleoptera, que vivem principalmente em águas limpas e bem oxigenadas. Por outro lado, maior densidade de insetos a deriva, especialmente Chironomidae, foi observada no riacho urbano, onde foram registrados elevados valores de pH, condutividade elétrica e nitrogênio. Estas larvas são capazes de explorar uma vasta gama de condições ambientais, consequência da sua grande capacidade de adaptação fisiológica. Apesar de ter encontrado os padrões esperados, não foram contatadas diferenças significativas na diversidade e abundância de espécies entre os riachos. Assim, a composição de espécies pode ser considerada como melhor preditora de impactos sobre a comunidade de insetos à deriva.(AU)

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RESUMO

Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

Resumo Riachos podem exibir diferenças na estrutura das comunidades de invertebrados à deriva, o que pode ser um reflexo da variação nos fatores ambientais, capazes de se alterar em condições de intervenções antrópicas. O objetivo deste trabalho foi analisar a composição, diversidade e abundância de insetos à deriva em dois riachos neotropicais sob diferentes usos do solo, além de identificar os fatores ambientais intervenientes na determinação de tais padrões. Foram registrados 54 táxons de insetos aquáticos nos riachos urbano e rural. Os resultados evidenciaram diferenças significativas na composição de espécies, devido à substituição de espécies especialistas por espécies generalistas no riacho urbano. Maior diversidade de táxons foi registrada no riacho rural, com altos níveis de oxigênio dissolvido e elevado fluxo hídrico, que favoreceram a ocorrência de grupos sensíveis a perturbações ambientais, como táxons das ordens Ephemeroptera, Plecoptera, Trichoptera e Coleoptera, que vivem principalmente em águas limpas e bem oxigenadas. Por outro lado, maior densidade de insetos a deriva, especialmente Chironomidae, foi observada no riacho urbano, onde foram registrados elevados valores de pH, condutividade elétrica e nitrogênio. Estas larvas são capazes de explorar uma vasta gama de condições ambientais, consequência da sua grande capacidade de adaptação fisiológica. Apesar de ter encontrado os padrões esperados, não foram contatadas diferenças significativas na diversidade e abundância de espécies entre os riachos. Assim, a composição de espécies pode ser considerada como melhor preditora de impactos sobre a comunidade de insetos à deriva.

RESUMO

This study analysed sea turtle strandings on the coast of Paraíba State, Northeastern Brazil, from August 2009 to July 2010. A total of 124 strandings were recorded in this period: green turtle Chelonia mydas (n = 106), hawksbill Eretmochelys imbricata (n = 15), olive ridley Lepidochelys olivacea (n = 2) and loggerhead Caretta caretta (n = 1). Of all turtles for which the Curved Carapace Length (CCL) was measured (n = 122), only 12 individuals (9.7%) were adults. Twenty individuals had synthetic anthropogenic debris in the gastrointestinal tract. Other traces of human interactions were observed in 43 individuals, such as injuries caused by entanglement in fishing lines or nets, collisions with vessels, direct contact with oil spills and lesions caused by sharp or spiked objects. Moreover, in 28.5% of the stranded turtles, the presence of external tumors was noticed, suggestive of fibropapillomatosis and in 9.7%, shark bite marks were observed. Of the 107 individuals that were sexed, 76 were females and 31 were males. Most turtles (72.6%) became stranded during the spring/summer (between October and March). We found evidence of human interactions (injuries) in half of the strandings, but in most cases it was not possible to determine if such interactions were the cause of death. A logistic regression found a significant relationship between CCL, ingestion of debris and lesions caused by sharks or spiked objects. Systematic data collection from stranded sea turtles can provide useful biological information, such as seasonal and spatial patterns in their occurrence and mortality, age structure, sex ratio and diet, as well as possible mortality causes.

Este estudo analisou encalhes de tartarugas marinhas na costa do Estado da Paraíba, Nordeste do Brasil, de agosto de 2009 a julho de 2010. Neste período, 124 encalhes foram registrados: tartaruga-verde Chelonia mydas (n = 106), tartaruga-de-pente Eretmochelys imbricata (n = 15), tartaruga-oliva Lepidochelys olivacea (n = 2) e cabeçuda Caretta caretta (n = 1). Dentre todas as tartarugas que tiveram o Comprimento Curvilíneo da Carapaça (CCC) medido (n = 122), apenas 12 indivíduos (9,7%) foram considerados adultos. Vinte indivíduos tinham detritos antropogênicos sintéticos no trato gastrointestinal. Em 43 indivíduos, outros vestígios de interações humanas foram observados, tais como lesões causadas por emaranhamento em linhas ou redes de pesca, colisões com embarcações, contato direto com derramamentos de óleo e lesões causadas por objetos perfurocortantes. Além disso, em 28,5% das tartarugas encalhadas, foi observada a presença de tumores externos sugestivos de fibropapilomatose e em 9,7%, foram observadas marcas de mordidas de tubarão. Dos 107 indivíduos sexados, 76 eram fêmeas e 31 eram machos. A maioria das tartarugas (72,6%) encalhou durante a primavera/verão (entre outubro e março). Foram encontrados sinais de interações humanas (lesões) em metade dos encalhes, mas na maioria dos casos, não foi possível determinar se tais interações foram a causa da morte. A regressão logística encontrou uma relação significativa entre CCC e ingestão de detritos, lesões causadas por objetos perfuro-cortantes e ataques de tubarões. A coleta sistemática de dados de tartarugas marinhas encalhadas pode fornecer informações biológicas úteis, tais como padrões sazonais e espaciais na sua ocorrência e mortalidade, estrutura etária, razão sexual, dieta, bem como possíveis causas de mortalidade.

Assuntos

RESUMO

This study analysed sea turtle strandings on the coast of Paraíba State, Northeastern Brazil, from August 2009 to July 2010. A total of 124 strandings were recorded in this period: green turtle Chelonia mydas (n = 106), hawksbill Eretmochelys imbricata (n = 15), olive ridley Lepidochelys olivacea (n = 2) and loggerhead Caretta caretta (n = 1). Of all turtles for which the Curved Carapace Length (CCL) was measured (n = 122), only 12 individuals (9.7%) were adults. Twenty individuals had synthetic anthropogenic debris in the gastrointestinal tract. Other traces of human interactions were observed in 43 individuals, such as injuries caused by entanglement in fishing lines or nets, collisions with vessels, direct contact with oil spills and lesions caused by sharp or spiked objects. Moreover, in 28.5% of the stranded turtles, the presence of external tumors was noticed, suggestive of fibropapillomatosis and in 9.7%, shark bite marks were observed. Of the 107 individuals that were sexed, 76 were females and 31 were males. Most turtles (72.6%) became stranded during the spring/summer (between October and March). We found evidence of human interactions (injuries) in half of the strandings, but in most cases it was not possible to determine if such interactions were the cause of death. A logistic regression found a significant relationship between CCL, ingestion of debris and lesions caused by sharks or spiked objects. Systematic data collection from stranded sea turtles can provide useful biological information, such as seasonal and spatial patterns in their occurrence and mortality, age structure, sex ratio and diet, as well as possible mortality causes.(AU)

Este estudo analisou encalhes de tartarugas marinhas na costa do Estado da Paraíba, Nordeste do Brasil, de agosto de 2009 a julho de 2010. Neste período, 124 encalhes foram registrados: tartaruga-verde Chelonia mydas (n = 106), tartaruga-de-pente Eretmochelys imbricata (n = 15), tartaruga-oliva Lepidochelys olivacea (n = 2) e cabeçuda Caretta caretta (n = 1). Dentre todas as tartarugas que tiveram o Comprimento Curvilíneo da Carapaça (CCC) medido (n = 122), apenas 12 indivíduos (9,7%) foram considerados adultos. Vinte indivíduos tinham detritos antropogênicos sintéticos no trato gastrointestinal. Em 43 indivíduos, outros vestígios de interações humanas foram observados, tais como lesões causadas por emaranhamento em linhas ou redes de pesca, colisões com embarcações, contato direto com derramamentos de óleo e lesões causadas por objetos perfurocortantes. Além disso, em 28,5% das tartarugas encalhadas, foi observada a presença de tumores externos sugestivos de fibropapilomatose e em 9,7%, foram observadas marcas de mordidas de tubarão. Dos 107 indivíduos sexados, 76 eram fêmeas e 31 eram machos. A maioria das tartarugas (72,6%) encalhou durante a primavera/verão (entre outubro e março). Foram encontrados sinais de interações humanas (lesões) em metade dos encalhes, mas na maioria dos casos, não foi possível determinar se tais interações foram a causa da morte. A regressão logística encontrou uma relação significativa entre CCC e ingestão de detritos, lesões causadas por objetos perfuro-cortantes e ataques de tubarões. A coleta sistemática de dados de tartarugas marinhas encalhadas pode fornecer informações biológicas úteis, tais como padrões sazonais e espaciais na sua ocorrência e mortalidade, estrutura etária, razão sexual, dieta, bem como possíveis causas de mortalidade.(AU)

Assuntos

RESUMO

Periphytic diatoms were sampled from two streams, one located in an urban area and the other located in a rural area, in Maringá, State of Paraná, Brazil. In addition to temporal variability, differences in the assemblage structure between streams were evaluated and correlated with physical and chemical characteristics. Six samples of periphytic diatoms were collected from each stream from July 2007 to June 2008. The streams differed in abiotic factors and in relation to the structure of diatom assemblages and the spatial scale was more important than the temporal scale (ANOVA, p 0.05; non-metric multidimensional scaling (NMS) stress = 13.73, p = 0.009). The Procrustes analysis (m2 = 0.7607 and p = 0.0001) showed that variables with the greatest influence on the assemblage structure of diatoms were total nitrogen (TN), electrical conductivity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and flow. These results indicate that abiotic variables modified by the land-use had greater influence on the community structure of diatoms than seasonal changes in abiotic variables.(AU)

Diatomáceas perifíticas foram amostradas em dois córregos, um localizado na zona urbana e outro na zona rural, situados em Maringá, Paraná, Brasil. Foram avaliadas as diferenças na estrutura da comunidade entre os córregos, relacionando-as às características físicas e químicas, bem como a variabilidade temporal. Seis amostras de diatomáceas perifíticas foram coletadas ao longo de cada córrego, de julho de 2007 a junho de 2008. Os córregos diferiram tanto em relação aos fatores abióticos como em relação à estrutura da comunidade de diatomáceas, e a escala espacial foi mais importante do que a escala temporal (ANOVA, p 0,05; NMS estresse = 13,73; p = 0,009). A análise de Procrustes (m2 = 0,7607 e p = 0,0001) mostrou que as variáveis com maior influência sobre a estrutura da comunidade de diatomáceas nos córregos estudados foram o nitrogênio total (NT), condutividade, oxigênio dissolvido (OD), demanda química do oxigênio (DQO), demanda bioquímica de oxigênio (DBO5) e velocidade da água. Os resultados indicam que as variáveis abióticas, alteradas pelo uso do solo, tiveram maior influência sobre a estrutura da comunidade de diatomáceas perifíticas do que a variação das condições abióticas devido às estações do ano.(AU)

Assuntos

RESUMO

Periphytic diatoms were sampled from two streams, one located in an urban area and the other located in a rural area, in Maringá, State of Paraná, Brazil. In addition to temporal variability, differences in the assemblage structure between streams were evaluated and correlated with physical and chemical characteristics. Six samples of periphytic diatoms were collected from each stream from July 2007 to June 2008. The streams differed in abiotic factors and in relation to the structure of diatom assemblages and the spatial scale was more important than the temporal scale (ANOVA, p ≥ 0.05; non-metric multidimensional scaling (NMS) stress = 13.73, p = 0.009). The Procrustes analysis (m 2 = 0.7607 and p = 0.0001) showed that variables with the greatest influence on the assemblage structure of diatoms were total nitrogen (TN), electrical conductivity, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and flow. These results indicate that abiotic variables modified by the land-use had greater influence on the community structure of diatoms than seasonal changes in abiotic variables.

Diatomáceas perifíticas foram amostradas em dois córregos, um localizado na zona urbana e outro na zona rural, situados em Maringá, Paraná, Brasil. Foram avaliadas as diferenças na estrutura da comunidade entre os córregos, relacionando-as às características físicas e químicas, bem como a variabilidade temporal. Seis amostras de diatomáceas perifíticas foram coletadas ao longo de cada córrego, de julho de 2007 a junho de 2008. Os córregos diferiram tanto em relação aos fatores abióticos como em relação à estrutura da comunidade de diatomáceas, e a escala espacial foi mais importante do que a escala temporal (ANOVA, p ≥ 0,05; NMS ­ estresse = 13,73; p = 0,009). A análise de Procrustes (m2 = 0,7607 e p = 0,0001) mostrou que as variáveis com maior influência sobre a estrutura da comunidade de diatomáceas nos córregos estudados foram o nitrogênio total (NT), condutividade, oxigênio dissolvido (OD), demanda química do oxigênio (DQO), demanda bioquímica de oxigênio (DBO5) e velocidade da água. Os resultados indicam que as variáveis abióticas, alteradas pelo uso do solo, tiveram maior influência sobre a estrutura da comunidade de diatomáceas perifíticas do que a variação das condições abióticas devido às estações do ano.

Assuntos