Net primary productivity and litter decomposition rates in two distinct Amazonian peatlands.

Measurements of net primary productivity (NPP) and litter decomposition from tropical peatlands are severely lacking, limiting our ability to parameterise and validate models of tropical peatland development and thereby make robust predictions of how these systems will respond to future environmental and climatic change. Here, we present total NPP (i.e., above- and below-ground) and decomposition data from two floristically and structurally distinct forested peatland sites within the Pastaza Marañón Foreland Basin, northern Peru, the largest tropical peatland area in Amazonia: (1) a palm (largely Mauritia flexuosa) dominated swamp forest and (2) a hardwood dominated swamp forest (known as 'pole forest', due to the abundance of thin-stemmed trees). Total NPP in the palm forest and hardwood-dominated forest (9.83 ± 1.43 and 7.34 ± 0.84 Mg C ha-1 year-1, respectively) was low compared with values reported for terra firme forest in the region (14.21-15.01 Mg C ha-1 year-1) and for tropical peatlands elsewhere (11.06 and 13.20 Mg C ha-1 year-1). Despite the similar total NPP of the two forest types, there were considerable differences in the distribution of NPP. Fine root NPP was seven times higher in the palm forest (4.56 ± 1.05 Mg C ha-1 year-1) than in the hardwood forest (0.61 ± 0.22 Mg C ha-1 year-1). Above-ground palm NPP, a frequently overlooked component, made large contributions to total NPP in the palm-dominated forest, accounting for 41% (14% in the hardwood-dominated forest). Conversely, Mauritia flexuosa litter decomposition rates were the same in both plots: highest for leaf material, followed by root and then stem material (21%, 77% and 86% of mass remaining after 1 year respectively for both plots). Our results suggest potential differences in these two peatland types' responses to climate and other environmental changes and will assist in future modelling studies of these systems.

Mediciones de la productividad primaria neta (PPN) y la descomposición de materia orgánica de las turberas tropicales son escasas, lo que limita nuestra capacidad para parametrizar y validar modelos de desarrollo de las turberas tropicales y, en consecuencia, realizar predicciones sólidas sobre la respuesta de estos sistemas ante futuros cambios ambientales y climáticos. En este estudio, presentamos datos de PPN total (es decir, biomasa aérea y subterránea) y descomposición de la materia orgánica colectada en dos turberas boscosas con características florísticas y estructurales contrastantes dentro de la cuenca Pastaza Marañón al norte del Perú, el área de turberas tropicales más grande de la Amazonia: (1) un bosque pantanoso dominado por palmeras (principalmente Mauritia flexuosa) y (2) un bosque pantanosos dominado por árboles leñosos de tallo delgado (conocido como 'varillal hidromórfico'). La PPN total en el bosque de palmeras y el varillal hidromórfico (9,83 ± 1,43 y 7,34 ± 0,84 Mg C ha­1 año­1 respectivamente) fue baja en comparación con los valores reportados para los bosques de tierra firme en la región (14,21­15,01 Mg C ha­1 año­1) y para turberas tropicales en otros lugares (11,06 y 13,20 Mg C ha­1 año­1). A pesar de que la PPN total fue similar en ambos tipos de bosque, hubo diferencias considerables en la distribución de la PPN. La PPN de las raíces finas fue siete veces mayor en el bosque de palmeras (4,56 ± 1,05 Mg C ha­1 año­1) que en el varillal hidromórfico (0,61 ± 0,22 Mg C ha­1 año­1). La PPN de la biomasa aérea de las palmeras, un componente ignorado frecuentemente, contribuyó en gran medida a la PPN total del bosque de palmeras, representando el 41% (14% en el varillal hidromórfico). Por el contrario, la tasa de descomposición de materia orgánica de Mauritia flexuosa fue la misma en ambos sitios: la más alta corresponde a la hojarasca, seguida por las raíces y luego el tallo (21%, 77% y 86% de la masa restante después de un año, respectivamente para ambos sitios). Nuestros resultados sugieren diferencias potenciales en la respuesta de estos dos tipos de turberas al clima y otros cambios ambientales, y ayudarán en futuros estudios de modelamiento de estos sistemas.

A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.

A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.

Social inequities in food deserts and food swamps in a northeastern Brazilian capital.

This study identified food deserts and swamps, investigating their associations with socioeconomic and demographic conditions. This ecological study was conducted using data from urban census tracts in the city of Recife, which were considered the unit of analysis. Information on food retail was obtained from government sources in 2019. Census tracts below the 25th percentile in the density of healthy food retail (i.e., those that predominantly sell natural or minimally processed foods, mixed businesses, and super- and hypermarkets) were classified as food deserts. Census tracts above the 25th percentile in the density of unhealthy food retail (i.e., those selling primarily ultra-processed foods) were considered food swamps. The socioeconomic and demographic conditions of the census tracts were evaluated using variables from the 2010 census (per capita income, average income, race, literacy of the head of household, and the availability of essential services) and the Health Vulnerability Index. Census tracts considered food deserts (28.5%) were more vulnerable, characterized by lower income and access to essential services, more illiterate residents and more minorities (Black/Indigenous/mixed race). Food swamps (73.47%) were more prevalent in less vulnerable neighbourhoods characterized by higher percentages of literate residents and Whites, greater purchasing power, and better basic sanitation. The characteristics of Recife's food deserts and swamps demonstrate social inequalities in the food environment. Public facilities could play a vital role in promoting healthy eating within food deserts. Additionally, future implementation of taxes on ultra-processed foods and the provision of tax subsidies to natural or minimally processed food sellers might contribute to fostering healthier dietary choices.

Occurrence and Health Risk Assessment of Heavy Metals in the Blue Land Crab (Cardisoma guanhumi) from a Tropical Mangrove Swamp.

Coastal ecosystems in the Caribbean are vulnerable to pollution from land-based activities with possible impacts to human health. Ten heavy metals in the blue land crab, Cardisoma guanhumi, harvested from the Caroni Swamp, Trinidad, were investigated in the wet and dry seasons. Metal concentrations (µg g-1 dry weight) in crab tissue were: As (0.15-6.46), Ba (0.69-19.64), Cd (< 0.001-3.36), Cr (0.63-3.64), Cu (26.64-120.31), Hg (0.09-1.83), Ni (1.21-9.33), Se (0.19-1.55), V (0.16-0.69) and Zn (121.06-494.3). There were seasonal differences in the concentration of some heavy metals and, Cu and Zn exceeded the local maximum permissible levels for fish and shellfish at several sites in either one or both seasons. Health risk assessment based on estimated daily intake, target hazard quotient and hazard index revealed that Cardisoma guanhumi harvested from the Caroni Swamp, does not pose a health risk to consumers.

Variation in phytoplankton diversity during phycoremediation in a polluted Colombian Caribbean swamp.

Phytoplankton composition and abundance are considered among the bioindicators of variations in water quality, due to its sensitivity and rapid responses to changes in environmental parameters. The selection and scaling of the Microalgal Predominant Microbial Consortium (MPMC) were based on live samples collected from the Santiago Apóstol Swamp (SAS) and the Arroyo Grande de Corozal (AGC). The inoculum was scaled in a phycoculture plant, and the inoculation process was performed in the AGC that flows into the SAS. The phytoplankton community monitoring was performed from May 2019 to September 2021. In the process, a total of 1,652,258 gallons were inoculated. Precisely, 103 and 124 species were found in the AGC and SAS, respectively. By evaluating the physical, chemical, and microbiological variables in SAS in a multitemporal way based on the inoculation of the MPMC, it is possible to identify the variables that presented the greatest reduction. The density of SAS presented associations with dissolved oxygen, thermotolerant coliforms, Enterococci, pH, phosphorus, nitrates, speed, and Secchi. The AGC and SAS presented high trophic levels (eutrophication). This contamination by organic matter is probably due to the discharges of the domestic tributaries. The diversity of microalgae and cyanobacteria found in this study allows us to know the anthropogenic impact. The density of microalgae showed the positive impact of the treatment with MCPM, where there was a decrease in the species that denote organic contamination. The phytoremediation treatment was effective in terms of the changes observed in the physicochemical variables, and these changes were directly due to the efficiency of the treatment and not the natural behavior of the water sources in the region.

The complete mitochondrial genome of the Mexican-endemic cavefish Ophisternoninfernale (Synbranchiformes, Synbranchidae): insights on patterns of selection and implications for synbranchiform phylogenetics.

Ophisternoninfernale is one of the 200+ troglobitic fish species worldwide, and one of the two cave-dwelling fishes endemic to the karstic aquifer of the Yucatán Peninsula, Mexico. Because of its elusive nature and the relative inaccessibility of its habitat, there is virtually no genetic information on this enigmatic fish. Herein we report the complete mitochondrial genome of O.infernale, which overall exhibits a configuration comparable to that of other synbranchiforms as well as of more distantly related teleosts. The KA/KS ratio indicates that most mtDNA PCGs in synbranchiforms have evolved under strong purifying selection, preventing major structural and functional protein changes. The few instances of PCGs under positive selection might be related to adaptation to decreased oxygen availability. Phylogenetic analysis of mtDNA comparative data from synbranchiforms and closely related taxa (including the indostomid Indostomusparadoxus) corroborate the notion that indostomids are more closely related to synbranchiforms than to gasterosteoids, but without rendering the former paraphyletic. Our phylogenetic results also suggest that New World species of Ophisternon might be more closely related to Synbranchus than to the remaining Ophisternon species. This novel phylogenetic hypothesis, however, should be further tested in the context of a comprehensive systematic study of the group.

Bioremediation of a Sewage-Contaminated Tropical Swamp Through Bioaugmentation with a Microalgae-Predominant Microbial Consortium.

Bioaugmentation has many applications as a bioremediation technique. It is usually performed by bacteria but microalgal consortia also have great potential for bioremediation. This study evaluated the ability of a microbial consortium with predominance of microalgae (MCPM) to decontaminate the water of the Mallorquín tropical swamp. The Mallorquín Swamp is a natural water reservoir, essential for the ecological and hydric balance of the region, as well as for the fishermen, but has received sewage for more than 20 years. Microalgae for bioremediation purposes were isolated from the swamp, selected, cultured in bioreactors, and poured back into the Mallorquín waters. After bioaugmentation, there was a significant reduction in the BOD5 (98%), nitrates (58%), enterococci (92%), and total coliforms (100%). Notably, despite the MCPM bioaugmentation, the original richness and abundance of phytoplankton in the Mallorquín swamp was not disrupted. These results confirm the benefits of phycoremediation as an effective tool for on-site bioremediation of natural water bodies and show an effective phycoremediation at a large scale without altering the autochthonous microalgae community. This constitutes the first report of a successful MCPM intervention performed at this scale in a natural swamp in Colombia. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-021-00990-y.

La suplementación estratégica de bucerros manejados en pasturas con predominio de Hymenachne amplexicaulis estimula las conductas de ingestión y mejora la ganancia de peso / Strategic supplementation of buffalo calves managed in pastures with a predominance of Hymenachne amplexicaulis stimulates ingestion behavior and improves weight gain

Introducción: En Colombia, la producción bufalina viene creciendo de forma importante. Los búfalos se adaptan bien a zonas aluviales, que se caracterizan por la presencia de especies de gramíneas nativas, como Hymenachne amplexicaulis. Objetivo: Evaluar el efecto de diferentes tipos de suplementación sobre el desempeño productivo y comportamiento ingestivo de bucerros manejados en pasturas con predominio de Hymenachne amplexicaulis. Materiales y métodos: Treinta bucerros Murrah, con 67.5 (DE=2) kg de peso y 4 meses de edad, se asignaron, aleatoriamente, sí son tres tratamientos: SS: sin suplementación; SM: suplemento mineral y SM+C: suplemento mineral + balanceado (0.5% peso corporal). Los animales pastorearon en praderas con predominio de Hymenachne amplexicaulis, y en la noche recibieron el suplemento en corrales. Las variables estudiadas fueron la ganancia de peso y el tiempo destinado a realizar diferentes conductas de ingestión, además de las tasas de bocados y estaciones de alimentación. Resultados: El consumo diario de mezcla mineral fue de 33.8 g en los dos grupos suplementados, y el de balanceado de 149.3 g. La oferta de SM y de SM+C produjo un incremento extra en la ganancia de peso de 68 y de 227 g, respectivamente (p <0.001). Los animales suplementados presentaron mayor tiempo de pastoreo (p<0.001) y menor tiempo de rumia (p =0.001). La relación beneficio/costo, para los tratamientos SM y SM+C, fue de 4.2 y 4.3, respectivamente. Conclusión: Bajo las condiciones de estudio, las dos estrategias de suplementación evaluadas mejoraron el desempeño de los animales y presentaron viabilidad económica, en especial la oferta simultanea de mezcla mineral y de alimento balanceado.

Introduction: In Colombia, buffalo production has been growing significantly. Buffaloes adapt well to alluvial areas, which are characterized by the presence of native grass species, such as Hymenachne amplexicaulis. Objective: To evaluate the effect of different strategies of supplementation on the productive performance and ingestive behavior of calves managed in pastures with a predominance of Hymenachne amplexicaulis. Materials and methods: Thirty Murrah calves, weighing 67.5 (SD=2) kg and 4 months old, were randomly assigned to three treatments: SS: no supplementation; SM: mineral supplement and SM+C: mineral supplement + concentrate (0.5% body weight). The animals grazed in meadows with a predominance of Hymenachne amplexicaulis, and at night they received the supplement in pens. The variables studied were weight gain and time spent on different eating behaviors, in addition to biting rate and feeding stations. Results: The mineral mixture consumption was 33.8 g in the SM and SM+C groups, and the balanced consumption was 149.3 g. The supply of SM and SM+C produced an extra increase in weight gain of 68 and 227 g, respectively (p < 0.001). Supplemented animals grazed longer (p<0.001) and ruminated less time (p =0.001). The benefit/cost ratio for the SM and SM+C treatments was 4.2 and 4.3, respectively. Conclusion: Under the study conditions, the supplementation strategies evaluated improved the performance of the animals and presented economic viability, especially the simultaneous offer of mineral mix and balanced feed.

Social inequalities in the surrounding areas of food deserts and food swamps in a Brazilian metropolis.

BACKGROUND: Food deserts are neighborhoods with little or no access to healthy food, whereas food swamps are neighborhoods where unhealthy food options prevail over healthy ones. The main aims of the current study are to feature and compare the neighborhoods of food deserts and food swamps based on social inequality. METHODS: Ecological study carried out in Belo Horizonte City, Minas Gerais State, Brazil. Information about commercial food establishments derived from two different databases. It was measured by secondary governmental databases, which were virtually conferred in the present study. Census tracts were considered as analysis units and classified as food deserts and food swamps, based on the Brazilian methodology. Take into consideration the density of establishments classified as selling fresh or minimally-processed food, mixed establishments, and establishments selling ultra-processed food. The Brazilian methodology evaluates food deserts by the density of healthy establishments (establishments classified as mostly selling fresh or minimally-processed food and mixed establishments) per 10 thousand inhabitants. And the metric to evaluate food swamps considers the density of unhealthy establishments (establishments mostly selling ultra-processed food) per 10 thousand inhabitants. Information about social inequalities comprised aspects such as income, population count, number of households, number of literate individuals, race, water and energy supply, and garbage collection. The Health Vulnerability Index (HVI) was used as a synthetic social vulnerability indicator. RESULTS: Neighborhoods of food deserts presented worse essential service availability, lower income per capita, and smaller mean number of literate individuals. Census tracts classified as food swamps presented better socio-demographic conditions than those areas food deserts. Neighborhoods simultaneously classified as food deserts and food swamps presented lower income per capita and were more often observed in census sectors presenting medium and high HVI. CONCLUSION: The food environment in Belo Horizonte was featured by the strong presence of food deserts and food swamps. However, the potential influence of these areas on food intake has changed depending on social inequalities.

Áreas en riesgo de invasión por Procambarus clarkii (Decapoda: Cambaridae) un cangrejo de río introducido en Colombia / Areas at risk of invasion by Procambarus clarkii (Decapoda: Cambaridae) a crayfish introduced in Colombia

Introducción: El proceso de invasión biológica es una de las mayores amenazas a la biodiversidad y ecosistemas, con actuales y potenciales impactos en la salud pública y conservación. Procambarus clarkii es un crustáceo decápodo, originario del sur de Estados Unidos y noreste de México, que puede adaptarse a diferentes condiciones ambientales debido a su plasticidad ecológica. Objetivo: Se caracterizó el nicho ecológico fundamental existente de Procambarus clarkii con el fin de predecir las áreas con idoneidad ambiental para el potencial establecimiento de la especie en Suramérica y Colombia. Métodos: Usamos modelos de nichos ecológicos calibrados en el área nativa, elaborados con el algoritmo Maxent, basados en datos de presencia extraídos de GBIF y variables hidroclimáticas de ecosistemas acuáticos a una resolución de 1 km2. Resultados: En Suramérica el modelo indicó un potencial geográfico amplio de invasión mostrando áreas ambientalmente idóneas para la presencia y expansión hacia Colombia, Venezuela, Perú, Ecuador, Brasil, Guyana, Surinam, Bolivia, Uruguay, Argentina, Paraguay y Chile. En Colombia, el modelo predijo que las áreas idóneas se ubican principalmente en el norte y oriente, incluidos diversos ecosistemas, como: bosques tropicales, bosques basales, bosques riparios y sabanas. La especie tiene una alta posibilidad de expandirse hacia áreas de distribución de latitudes bajas, ocupando zonas hacia la parte norte de la región Caribe colombiana, en departamentos de Magdalena, Cesar, Córdoba y Atlántico. También se predijo áreas con idoneidad ambiental en el oriente de Colombia, hacia la extensión de la planicie oriental de la Orinoquia, una región de baja altitud en: Arauca, Casanare, Meta y Vichada. Conclusión: En este estudio se aplican modelos de nichos ecológicos, que puede ser de interés en la planeación de estrategias o la creación de planes de manejo, como sistemas de alerta temprana para evitar el establecimiento de esta especie.

Introduction: Biological invasions are a major threat to biodiversity and ecosystems, with current and potential impacts on public health and conservation. Procambarus clarkii is a decapod crustacean, native to the Southern United States and Northeastern Mexico, which may adapt to different environmental conditions due to its ecological plasticity. Objective: The existing fundamental ecological niche of Procambarus clarkii was characterized in order to predict areas with environmental suitability for the potential establishment of the species in South America and Colombia. Methods: We used models of calibrated ecological niches in the native area, elaborated with the Maxent algorithm, based on occurrence data extracted from GBIF and hydroclimatic variables of aquatic ecosystems at a resolution of 1 km2. Results: The model indicated a wide geographic area for invasion potential in South America, predicting environmentally suitable areas for the presence and expansion towards Colombia, Venezuela, Peru, Ecuador, Brazil, Guyana, Surinam, Bolivia, Uruguay, Argentina, Paraguay and Chile. In Colombia, suitable areas predicted by the model are located mainly in the North and East of the country, spanning a diversity of ecosystems, such as tropical forests, basal forests, riparian forests and savannas. The species has a high possibility of expanding into low latitude distribution areas, occupying areas towards the Northern part of the Colombian Caribbean region, in the departments of Magdalena, Cesar, Cordoba and Atlántico. Suitability areas environmental were also predicted in Eastern Colombia, towards the extension of the Eastern plain of the Orinoquia, a low altitude region in Arauca, Casanare, Meta and Vichada. Conclusion: This study applies ecological niche models, which may be of interest in the planning of strategies or the creation of management plans, such as early warning systems that prevent the establishment of this species.

Spatial and temporal variability of soil N2 O and CH4 fluxes along a degradation gradient in a palm swamp peat forest in the Peruvian Amazon.

Mauritia flexuosa palm swamp, the prevailing Peruvian Amazon peatland ecosystem, is extensively threatened by degradation. The unsustainable practice of cutting whole palms for fruit extraction modifies forest's structure and composition and eventually alters peat-derived greenhouse gas (GHG) emissions. We evaluated the spatiotemporal variability of soil N2 O and CH4 fluxes and environmental controls along a palm swamp degradation gradient formed by one undegraded site (Intact), one moderately degraded site (mDeg) and one heavily degraded site (hDeg). Microscale variability differentiated hummocks supporting live or cut palms from surrounding hollows. Macroscale analysis considered structural changes in vegetation and soil microtopography as impacted by degradation. Variables were monitored monthly over 3 years to evaluate intra- and inter-annual variability. Degradation induced microscale changes in N2 O and CH4 emission trends and controls. Site-scale average annual CH4 emissions were similar along the degradation gradient (225.6 ± 50.7, 160.5 ± 65.9 and 169.4 ± 20.7 kg C ha-1  year-1 at the Intact, mDeg and hDeg sites, respectively). Site-scale average annual N2 O emissions (kg N ha-1  year-1 ) were lower at the mDeg site (0.5 ± 0.1) than at the Intact (1.3 ± 0.6) and hDeg sites (1.1 ± 0.4), but the difference seemed linked to heterogeneous fluctuations in soil water-filled pore space (WFPS) along the forest complex rather than to degradation. Monthly and annual emissions were mainly controlled by variations in WFPS, water table level (WT) and net nitrification for N2 O; WT, air temperature and net nitrification for CH4 . Site-scale N2 O emissions remained steady over years, whereas CH4 emissions rose exponentially with increased precipitation. While the minor impact of degradation on palm swamp peatland N2 O and CH4 fluxes should be tested elsewhere, the evidenced large and variable CH4 emissions and significant N2 O emissions call for improved modeling of GHG dynamics in tropical peatlands to test their response to climate changes.

Analysis of the population structure and genetic diversity of the red swamp crayfish (Procambarus clarkii) in China using SSR markers

BACKGROUND: Procambarus clarkii produces high-quality, delicious meat that is high in protein, low in fat, and rich in calcium and phosphorus. It has become an important aquatic resource in China. Our objectives are (i) to analyze the level of genetic diversity of P. clarkii populations; (ii) to explore the genetic differentiation (Gst); and (iii) to propose appropriate strategies for the conservation. RESULTS: In this study, Shannon's index (I) and Nei's gene diversity index (H) for P. clarkii were high (I = 0.3462 and H = 0.2325 on average and I = 0.6264, H = 0.4377 at the species level) based on the SSR markers. The expected heterozygosity value of 17 microsatellite loci in 25 crayfish populations was 0.9317, the observed heterozygosity value was 0.9121, and the observed number of alleles per locus was 2.000; and the effective number of alleles per locus was 1.8075. Among the P. clarkii populations, the inbreeding coefficient within populations (Fis) was 0.2315, overall inbreeding coefficient (Fit) was 0.4438, genetic differentiation coefficient among populations (Fst) was 0.3145 and gene differentiation (Gst) was 0.4785 based on SSR analyses. The cluster analysis results obtained by unweighted pair-group method with arithmetic mean (UPGMA) analysis, principal coordinate analysis (PCoA) and STRUCTURE analysis were similar. A mantel test showed that the isolation-by-distance pattern was not significant. CONCLUSIONS: The high Gst among P. clarkii populations is attributed to genetic drift and geographic isolation. The results indicated that more P. clarkii populations should be collected when formulating conservation and aquaculture strategies.

Mercury contamination levels in the bioindicator piscivorous fish Hoplias aïmara in French Guiana rivers: mapping for risk assessment.

In French Guiana, native populations present high level of mercury contamination, which has been linked to the consumption of contaminated fishes. The goal of this study is to undertake a cartography of mercury contamination levels in fishes from the six main Guiana rivers. The selected species for this study is the ubiquitous piscivorous fish Hoplias aimara. A total number of 575 fishes from 134 discrete fishing sites are regrouped into 51 river sectors. Results from this study permits to rank the six main Guiana rivers by their mean level of contamination: Oyapock (0.548 mg kg-1), Comté (0.624 mg kg-1), Maroni (0.671 mg kg-1), Approuague (0.684 mg kg-1), Mana (0.675 mg kg-1), and Sinnamary (1.025 mg kg-1). The contamination is however not spatially homogenous along each river, and a map of the different levels of mercury contamination in fishes is provided. Sectors of low mean Hg contamination are observed both upstream (0.471 mg kg-1) and downstream (0.424 mg kg-1), corresponding to areas without any influence of gold mining activities and areas under the influence of estuarine dilution, respectively. Anoxia and gold mining activities are found to be the two main factors responsible for the high mercury concentration in fish muscles. While mean levels of mercury contaminations are higher in anoxia areas (1.029 mg kg-1), contaminations induced by gold mining activities (0.717 mg kg-1) present the most harmful consequences to human populations. No significant differences in Hg concentrations are observed between 2005 and 2014 for neither a pristine nor a gold mining area, while Hg concentration differences are observed between former (0.550 mg kg-1) and current gold mining sites (0.717 mg kg-1).

PARÁMETROS ESTRUCTURALES DE DOS POBLACIONES DE Crassostrea rhizophorae (OSTREIDAE) EN BAHÍA CISPATÁ, CARIBE COLOMBIANO / Structural Parameters of Two Populations of Crassostrea rhizophorae (Ostreidae) in Bahía Cispatá, Colombian Caribbean

RESUMEN La ostra del mangle es una especie de gran importancia ecológica y comercial en muchos lugares del Caribe. En Bahía de Cispatá, Colombia, no obstante, representa el sustento económico de un importante grupo de pescadores se carece de planes de manejo que regulen su extracción. El objetivo del presente estudio fue el de establecer la estructura poblacional de Crassostrea rhizophorae en Bahía Cispatá, como insumo básico para la formulación futura de planes de manejo de la especie. Debido a las diferencias fenotípicas observadas entre los individuos de los lugares muestreados, se obtuvieron secuencias del gen COI, concluyendo que todos los individuos corresponden a la especie Crassostrea rhizophorae. Con base en las características morfológicas se diferenciaron dos poblaciones, de las que no se evidenció coexistencia en una misma estación de muestreo. A través del programa FiSAT se evaluaron los principales parámetros poblacionales, encontrando que los individuos de la población con concha delgada crecen a mayor velocidad alcanzando mayores tamaños que los individuos de la población de conchas más robustas y fuertes. No obstante, los individuos de concha delgada también presentaron una tasa de mortalidad más alta. Para las dos poblaciones la oferta alimentaria fue muy baja, lo cual pudo haber influido en la baja densidad poblacional encontrada durante 2015. Es necesario resaltar la importancia del recurso ostra en la zona y la ventaja que representa para los pescadores, los especímenes de concha más robusta, los cuales pueden ser mantenidos por más tiempo sin congelar que los de concha delgada.

ABSTRACT The mangrove oyster is a species of great ecological and commercial importance in many places in the Caribbean. In Bahía de Cispatá, Colombia, the oyster represents the economic support of an important group of fishermen lacks management plans for the extraction regulation. The objective of the present study was to establish the population structure of Crassostrea rhizophorae in Bahía Cispatá, as a basic input for the future formulation of management plans. Due to the morphological differences observed among the individuals of the sampled sites, sequences of the COI gene were obtained, concluding that all individuals correspond to the species Crassostrea rhizophorae. Based on the morphological differences, two populations were differentiated, which did not show coexistence in the same sampling station. Through the FiSAT program, the main population parameters were evaluated, finding that individuals of the population with thin shells grow at a faster rate, reaching greater sizes than individuals from the population of more robust and strong shells. However, individuals with thin shells also had higher mortality rates. For both populations, the food supply was very low, which may have influenced the low population density found during 2015. It is important to highlight the importance of this resource in the area and the advantage presented by the more robust oyster's specimens for fishermen since is that it allows them to have it to be stored for longer than the thin shell oyster.

Females of two species of Argia from Chapada dos Guimarães National Park, Brazil (Odonata: Coenagrionidae).

The female of Argia tupi Calvert, 1909 (BRAZIL, Mato Grosso, Chapada dos Guimarães National Park, Cachoeira do Marimbondo (15.4330° S, 55.7198° W, 370 m), 01 xi 2015) is described, illustrated and diagnosed based on comparison with sympatric species of Argia Rambur, 1842. We also augmented the description of Argia bicellulata (Calvert, 1909) female (BRAZIL, Mato Grosso, Chapada dos Guimarães National Park, Rio Paciencia (15.3438° S, 55.8322° W, 280 m), 25 x 2015).

The effect of seasonal and human pressure on macrobenthic fauna in the Caroni Swamp Ramsar Site, Trinidad and Tobago / Efecto de la presión estacional y humana en la fauna macrobentónica del sitio Ramsar pantano Caroní, Trinidad y Tobago

Abstract Human pressures have placed many tropical estuaries in developing countries under increased levels of stress. The Caroni Swamp Ramsar Site, the largest mangrove swamp along the west coast of Trinidad, has been subjected to high levels of anthropogenic impacts including hydrological alteration and pollution from land-based sources since the 1920's. While most of these impacts have been well documented, limited information exists on the macrobenthic communities in the swamp. This study addresses the paucity of information. The macrobenthic fauna in the main waterways of Caroni Swamp was sampled at 12 locations using a Van Veen 0.025 m2 grab, once in the dry (April) and wet (August) season of 2015 with a total of 144 samples. The samples were sorted, counted and species were identified to the lowest possible taxonomic level. A total of 55 taxa were identified with polychaetes being the most abundant taxa. The ecological status of the macrobenthos was assessed using AZTI's Marine Biotic Index (AMBI) and the multivariate-AMBI (M-AMBI). Physicochemical parameters were measured with a YSI multiparameter metre. Chemical analyses were also conducted on nitrates, nitrites, ammonia and reactive phosphates using standard methods. Overall, AMBI characterised the Caroni Swamp as "slightly disturbed" with a macrobenthic community of "poor" ecological status according to M-AMBI. Generally, the quality of the environment improves from the dry season to the wet season. However, seasonal variations in AMBI and M-AMBI were found to be site specific as some showed improvement in ecological status and macrozoobenthos quality while others showed degradation from the dry season to the wet season. The stations to the North of the swamp showed improvement from the dry season to the wet season while the opposite was observed in the more Southern stations. One notable characteristic of the swamp was the high levels of pollutants, particularly ammonia, recorded in one of its major waterways, the Caroni River. This is in contrast to the other waterways within the swamp which experience much lower levels of pollutant input from land-based sources. The assessment of the Caroni Swamp using AMBI and M-AMBI may be useful for informing management strategies to conserve the wetland and improve environmental quality. Rev. Biol. Trop. 66(3): 1101-1117. Epub 2018 September 01.

Resumen Los estuarios tropicales de países en desarrollo han experimentado un aumento en los niveles de estrés debido a la presión humana. El sitio Ramsar pantano Caroní, el manglar más grande de la costa oeste de Trinidad, ha estado sujeto a altos niveles de impacto antropogénico, incluyendo alteraciones hidrológicas y contaminación de fuentes terrestres desde la década de 1920. Aunque la mayoría de estos impactos han sido bien documentados, existe información limitada sobre las comunidades macrobentónicas en el pantano. Este estudio aborda esta escasez de información. Se muestreó la fauna macrobentónica en el canal principal del pantano Caroní en 12 localidades utilizando una draga Van Veen de 0.025 m2, una vez durante la época seca (Abril) y la época lluviosa (Agosto) 2015, con un total de 144 muestras. Las muestras fueron ordenadas, contadas y las especies se identificaron al menor nivel taxonómico posible. Se identificaron un total de 55 taxa, siendo los poliquetos el taxa más abundante. El estatus ecológico del macrobentos se evaluó utilizando el Índice Marino Biótico de AZTI (AMBI) y el AMBI-multivariado (M-AMBI). Los parámetros fisicoquímicos se midieron con un multiparámetro YSI. Los análisis químicos también se realizaron para nitratos, nitritos, amonio y fostatos activos utilizando métodos estándar. En conjunto, el índice AMBI caracterizó el pantano Caroní como "levemente alterado" con una comunidad macrobentónica de categoría "pobre" de acuerdo al M-AMBI. Generalmente, la calidad de los ambientes incrementa desde la época seca hasta la época lluviosa. Sin embargo, las variaciones estacionales en los índices AMBI y M-AMBI fueron específicas a la localidad, mostrando algunas un incremento en el estatus ecológico y calidad del macrozoobentos, mientras que otros mostraron una degradación de la época seca a la época lluviosa. Las estaciones al norte del pantano mostraron una mejora de la época seca a la época lluviosa, mientras que se presentó lo contrario en las estaciones más al sur. Una característica notable del pantano fueron los altos niveles de contaminantes, particularmente amonio, registrado en uno de los canales principales del río Caroní. Esto contrasta con los otros canales del pantano que experimentan niveles menores de aporte de contaminantes de fuentes terrestres. La evaluación del pantano Caroní utilizando los índíces AMBI y M-AMBI puede ser una base útil de información para las estrategias de manejo y conservación del humedal y mejorar su calidad ambiental.

Management of invasive populations of the freshwater crayfish Procambarus clarkii (Decapoda, Cambaridae): test of a population-control method and proposal of a standard monitoring approach.

Invasive species are one of the main threats to biodiversity. When an alien species is introduced into a new environment, fast identification and definition of management strategies may avoid or minimize impacts. When an invasive species is already established, the most adopted approaches are population control and monitoring. In order to perform such strategies, assessment of characteristics of the invasive population is imperative. This study tested a new method of population size estimation and monitoring in an invasive population of crayfish Procambarus clarkii in a conservation area in the Atlantic Rain Forest (Southeastern Brazil). The population dynamics was studied for 1 year to examine the efficacy of the selected method and to evaluate if the population is stable. Later, the effect of periodical removal of animals on the population size was tested. The method of population estimation used in this study proved to be very effective. We recommend using it to monitor invasive populations of P. clarkii. The population size varied discretely over the year with variable but low growth rate, indicating that the population is already established which introduce a notable threat to native species. The continuous removal of specimens proved to be inefficient since the growth rate was higher after the removal. One intensive removal event might be more effective than a continuous moderate removal as the one applied in this study.

Ecosystem state shifts during long-term development of an Amazonian peatland.

The most carbon (C)-dense ecosystems of Amazonia are areas characterized by the presence of peatlands. However, Amazonian peatland ecosystems are poorly understood and are threatened by human activities. Here, we present an investigation into long-term ecohydrological controls on C accumulation in an Amazonian peat dome. This site is the oldest peatland yet discovered in Amazonia (peat initiation ca. 8.9 ka BP), and developed in three stages: (i) peat initiated in an abandoned river channel with open water and aquatic plants; (ii) inundated forest swamp; and (iii) raised peat dome (since ca. 3.9 ka BP). Local burning occurred at least three times in the past 4,500 years. Two phases of particularly rapid C accumulation (ca. 6.6-6.1 and ca. 4.9-3.9 ka BP), potentially resulting from increased net primary productivity, were seemingly driven by drier conditions associated with widespread drought events. The association of drought phases with major ecosystem state shifts (open water wetland-forest swamp-peat dome) suggests a potential climatic control on the developmental trajectory of this tropical peatland. A third drought phase centred on ca. 1.8-1.1 ka BP led to markedly reduced C accumulation and potentially a hiatus during the peat dome stage. Our results suggest that future droughts may lead to phases of rapid C accumulation in some inundated tropical peat swamps, although this can lead ultimately to a shift to ombrotrophy and a subsequent return to slower C accumulation. Conversely, in ombrotrophic peat domes, droughts may lead to reduced C accumulation or even net loss of peat. Increased surface wetness at our site in recent decades may reflect a shift towards a wetter climate in western Amazonia. Amazonian peatlands represent important carbon stores and habitats, and are important archives of past climatic and ecological information. They should form key foci for conservation efforts.

Density and diversity of filamentous fungi in the water and sediment of Araçá bay in São Sebastião, São Paulo, Brazil / Densidade e diversidade de fungos filamentosos na água e sedimento da Baía do Araçá, São Sebastião (SP), Brasil

Abstract Araçá Bay, located in the city of São Sebastião, São Paulo, Brazil, is a protected area of substantial complexity. It represents the last remaining mangrove swamp preserve between the cities of Bertioga and Ubatuba on the northern coast of São Paulo State. This mangrove swamp has specific physical and chemical properties, and it shelters a wide variety of life, including fungi. These microorganisms are present in a variety of species with different morphophysiological features, and they have the ability to produce enzymes of biotechnological importance. The goal of this study was to quantify, isolate, and identify filamentous fungi in water and sediment samples from the Araçá Bay mangrove swamp in São Sebastião. Two samplings were performed in the summer and two were performed in the winter. The samples were collected from intertidal zones, and dissolved oxygen (DO), temperature, salinity, and pH were measured in situ. The spread plate technique was used to inoculate the samples collected on plates with a potato dextrose agar (PDA) medium. A total of 208 colonies (68 from water samples and 140 from sediment samples) were isolated, and they were identified based on their morphological characteristics. Filamentous fungus density was higher in the sediment than in the water, and the samplings performed in the winter revealed a higher density than those performed in the summer. Though some of the environmental parameters were not ideal for fungal development, a high quantity of growth was nevertheless observed. When the isolated colonies were analyzed, the greatest diversity and species richness were found in the summer samples. The genera identified in all of the samples were Aspergillus, Penicillium, Cladosporium, and Fusarium. The pathogenic species found from these genera were Aspergillus fumigatus, A. terreus, Penicillium citrinum, and P. chrysogenum. These species are also able to produce enzymes that offer a variety of applications. The fungal community described herein represents the diversity found in this mangrove swamp during the period studied. Many of the fungus species found are pathogenic and may be useful due to their ability to produce specific enzymes applicable in the biotechnological and pharmaceutical industries.

Resumo A Baía do Araçá, localizada no município de São Sebastião (SP), é uma região protegida, de grande complexidade, mantendo o último remanescente preservado de manguezal entre Bertioga e Ubatuba, litoral Norte do Estado de São Paulo. Manguezal caracteriza-se com propriedades físico-químicas específicas e abriga grande diversidade de seres vivos, entre eles os fungos. Estes microrganismos apresentam grande variedade de espécies e diferentes características morfofisiológicas com capacidade de produzir algumas enzimas de importância biotecnológica. Este trabalho teve como objetivo quantificar, isolar e identificar fungos filamentosos em amostras de água e de sedimento do manguezal da Baía do Araçá, São Sebastião, (SP). Foram realizadas 2 coletas no verão e 2 no inverno na região entremarés, medidos "in situ" os parâmetros oxigênio dissolvido (OD), temperatura, salinidade e pH. Utilizou-se a Técnica "Spread Plate" para inocular os materiais coletados, em placas com meio Potato Dextrose Agar (PDA). Foram isoladas 208 colônias (68 das amostras de água e 140 das amostras de sedimento) e identificadas pelas características morfofisiológicas. As densidades de fungos filamentosos foram maiores no sedimento em relação à água e nas coletas realizadas no inverno demonstraram maiores densidades do que no verão. Apesar de alguns parâmetros ambientais não se apresentarem ideais para o desenvolvimento dos fungos, observou-se alta quantidade de crescimento nas amostragens. Analisando as colônias isoladas, a maior diversidade e riqueza foram observadas na amostragem coletado no verão. Foram observados os gêneros Aspergillus sp, Penicillium sp, Cladosporium sp e Fusarium sp em todas as amostragens, dos quais as espécies Aspergillus fumigatus, A. terreus, Penicillium citrinum e P. chrysogenum identificados neste trabalho são considerados patogênicos mas também são espécies capazes de produzir enzimas aplicáveis em diversas atividades. A comunidade fúngica descrita apresenta a diversidade encontrada neste manguezal em relação à variedade ambiental no período estudado, sendo que muitos apresentam patogenicidade e podem ser uteis pela sua capacidade de produzir enzimas específicas aplicáveis nos estudos biotecnológicos e farmacêuticos.

How Latina mothers navigate a 'food swamp' to feed their children: a photovoice approach.

OBJECTIVE: To understand how mothers who recently migrated from Central America to the USA feed their children in a neighbourhood saturated with unhealthful food choices ('food swamp') and to formulate a mother-driven plan of action to facilitate their acquisition of foods. Design/Setting/Subjects We purposively sampled mothers with children (<10 years old) who were recent immigrants/refugees from Central America and lived in a 'food swamp' neighbourhood. We used the photovoice approach to elicit textual data from thirty in-depth interviews, a participatory workshop, and visual data from photographs. Analyses were guided by the Social Ecological Framework and Social Cognitive Theory to identify barriers, facilitators and strategies that support parents in feeding their children. RESULTS: Mothers valued foods that they considered to be 'traditional' and 'healthful'. They navigated their food retail environment looking for these foods (of good quality and well-priced). Food values were reinforced by pre-migration food customs and culture, health professionals' advice and, in some cases, by the desire to avoid conflict with their children. The neighbourhood food environment could directly influence children's food preferences and often created conflict between what the child wanted to eat and the foods that mothers valued. Mothers in this 'food swamp' wanted to be engaged in addressing the selection of foods offered in schools and in neighbourhood food venues to reflect their own food values. CONCLUSIONS: These mothers' feeding choices were influenced directly by their food values, and indirectly by the neighbourhood and school food environments via their children's preferences.