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1.
JAMA Netw Open ; 4(10): e2130800, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34714342

RESUMO

Importance: Although there are reports of COVID-19 vaccine implementation in real-world populations, these come from high-income countries or from experience with messenger RNA technology vaccines. Data on outcomes of vaccine deployment in low- or middle-income countries are lacking. Objective: To assess whether the pragmatic application of the 3 COVID-19 vaccines available in Argentina, 2 of which have no reports of evaluation in real-world settings to date, were associated with a reduction in morbidity, all-cause mortality, and mortality due to COVID-19. Design, Setting, and Participants: This cohort study used individual and ecological data to explore outcomes following vaccination with rAd26-rAd5, ChAdOx1, and BBIBP-CorV. To correct for differences in exposure times, results are shown using incidence density per 100 000 person-days from the start of the vaccination campaign (December 29, 2020) to the occurrence of an event or the end of follow-up (May 15, 2021). Participants included 663 602 people aged at least 60 years residing in the city of Buenos Aires, Argentina. Statistical analysis was performed from June 1 to June 15, 2021. Main Outcomes and Measures: Diagnosis of COVID-19 confirmed by reverse transcription-polymerase chain reaction, death from all causes, and death within 30 days of a diagnosis of COVID-19. Poisson regression models were fitted to estimate associations with all 3 outcomes. Results: Among 663 602 residents of the city of Buenos Aires included in the study, 540 792 (81.4%) were vaccinated with at least 1 dose, with 457 066 receiving 1 dose (mean [SD] age, 74.5 (8.9) years; 61.5% were female [n = 281 284]; 68.0% [n = 310 987] received the rAd26-rAd5 vaccine; 29.5% [n = 135 036] received ChAdOx1; 2.4% [n = 11 043] received BBIBP-CorV) and 83 726 receiving 2 doses (mean [SD] age, 73.4 [6.8] years; 63.5% were female [n = 53 204]). The incidence density of confirmed COVID-19 was 36.25 cases/100 000 person-days (95% CI, 35.80-36.70 cases/100 000 person-days) among those who did not receive a vaccine, 19.13 cases/100 000 person-days (95% CI, 18.63-19.62 cases/100 000 person-days) among those who received 1 dose, and 4.33 cases/100 000 person-days (95% CI, 3.85-4.81 cases/100 000 person-days) among those who received 2 doses. All-cause mortality was 11.74 cases/100 000 person-days (95% CI, 11.51-11.96 cases/100 000 person-days), 4.01 cases/100 000 person-days (95% CI, 3.78-4.24 cases/100 000 person-days) and 0.40 cases/100 000 person-days (95% CI, 0.26-0.55 cases/100 000 person-days). COVID-19-related-death rate was 2.31 cases/100 000 person-days (95% CI, 2.19-2.42 cases/100 000 person-days), 0.59 cases/100 000 person-days (95% CI, 0.50-0.67 cases/100 000 person-days), and 0.04 cases/100 000 person-days (95% CI, 0.0-0.09 cases/100 000 person-days) among the same groups. A 2-dose vaccination schedule was associated with an 88.1% (95% CI, 86.8%-89.2%) reduction in documented infection, 96.6% (95% CI, 95.3%-97.5%) reduction in all-cause death, and 98.3% (95% CI, 95.3%-99.4%) reduction in COVID-19-related death. A single dose was associated with a 47.2% (95% CI, 44.2%-50.1%) reduction in documented infection, 65.8% (95% CI, 61.7%-69.5%) reduction in all-cause death, and 74.5% (95% CI, 66%-80.8%) reduction in COVID-19-related death. Conclusions and Relevance: This study found that within the first 5 months after the start of the vaccination campaign, vaccination was associated with a significant reduction in COVID-19 infection as well as a reduction in mortality.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Programas de Imunização , Cobertura Vacinal/estatística & dados numéricos , Idoso , Argentina/epidemiologia , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/mortalidade , COVID-19/prevenção & controle , Teste de Ácido Nucleico para COVID-19/métodos , Vacinas contra COVID-19/classificação , Vacinas contra COVID-19/uso terapêutico , Estudos de Coortes , Monitorização de Parâmetros Ecológicos/métodos , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Feminino , Humanos , Programas de Imunização/métodos , Programas de Imunização/organização & administração , Programas de Imunização/estatística & dados numéricos , Incidência , Masculino , Pessoa de Meia-Idade , Mortalidade , SARS-CoV-2/imunologia , Potência de Vacina
2.
Sci Rep ; 11(1): 19294, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588496

RESUMO

The raccoon (Procyon lotor) is an invasive carnivore that invaded various areas of the world. Although controlling feral raccoon populations is important to reduce serious threats to local ecosystems, raccoons are not under rigid population control in Europe and Japan. We examined the D-loop and nuclear microsatellite regions to identify spatially explicit and feasible management units for effective population control and further range expansion retardation. Through the identification of five mitochondrial DNA haplotypes and three nuclear genetic groups, we identified at least three independent introductions, range expansion, and subsequent genetic admixture in the Boso Peninsula. The management unit considered that two were appropriate because two populations have already genetic exchange. Furthermore, when taking management, we think that it is important to monitor DNA at the same time as capture measures for feasible management. This makes it possible to determine whether there is a invasion that has a significant impact on population growth from out of the unit, and enables adaptive management.


Assuntos
Espécies Introduzidas , Guaxinins/genética , Animais , DNA Mitocondrial , Monitorização de Parâmetros Ecológicos/métodos , Ecossistema , Feminino , Variação Genética , Genética Populacional , Haplótipos , Japão , Masculino , Repetições de Microssatélites
4.
Sci Rep ; 11(1): 18987, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556696

RESUMO

Detection of environmental DNA (eDNA) has become a commonly used surveillance method for threatened or invasive vertebrates in both aquatic and terrestrial environments. However, most studies in this field favor vertebrate target species. Environmental DNA protocols can be especially useful for endangered invertebrates such as the Hine's emerald dragonfly (Somatochlora hineana) where conservation efforts have been greatly hindered by training, time, overall costs, and environmental impacts associated with conducting surveys in the calcareous fens occupied by this species. An essential step in developing such a protocol is to evaluate the dynamics of eDNA concentration under controlled conditions. We used the quantitative polymerase chain reaction (qPCR) to examine seasonal shifts in the persistence and net-accumulation of eDNA from captive S. hineana larvae in experimental mesocosms at temperatures corresponding with their overwintering (5.0 °C) and active (16.0 °C) seasons. Environmental DNA persisted longer at 5.0 °C but accumulated more readily at 16.0 °C. Differences in the accumulation and persistence of eDNA reflect differences in the longevity of eDNA at different temperatures and seasonal differences in larval S. hineana behavior. This study highlights the importance of considering how seasonal changes in temperature influence not only the speed of eDNA degradation but also the target species' eDNA shedding rates.


Assuntos
DNA Ambiental/isolamento & purificação , Monitorização de Parâmetros Ecológicos/métodos , Espécies em Perigo de Extinção/estatística & dados numéricos , Odonatos/genética , Animais , DNA Ambiental/química , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Estudos de Viabilidade , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Temperatura
5.
PLoS One ; 16(7): e0253737, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34260603

RESUMO

Southern fin whales (Balaenoptera physalus) are known to migrate from the Antarctic to mid-latitudes during winter for breeding, but the occurrence and distribution of this species is not well known in the waters around New Zealand. The 'doublet' calls are one of the main calls emitted specifically by fin whales and repeated in a regular pattern, which make the acoustic detection of these calls relevant to detect the presence of fin whales. Using a signal processing algorithm to detect 'doublet' calls emitted by fin whales, we studied the occurrence, characteristics and seasonality of these 'doublet' calls in two regions around New Zealand; Cook Strait in 2016/2017 and offshore Gisborne in 2014/2015. The call detection procedure consisted of binarization of the spectrogram and a cross-correlation between the binarized spectrogram and a template of binarized 'doublet' calls spectrogram. A binarization threshold for the data spectrograms and a cross correlation threshold were then determined through multiple trials on a training dataset and a Receiver Operating Characteristics (ROC) curve. Fin whale 'doublet' calls occurred on the east side of New Zealand's Cook Strait during austral winter, specifically in June 2017 and offshore Gisborne in June-August 2014. No 'doublet' calls were detected on the west side of Cook Strait. The 'doublet' calls' Inter-Note Interval (INI) was similar in both datasets. However, there was a difference in alternation of the mean frequency for both HF components of 'doublet' calls in Cook Strait and Gisborne. As the song types were compared with those previously described in the literature, our findings suggest that some fin whales wintering in New Zealand waters may be part of a broader 'acoustic population' whose range extends west to southern Australia and south to Antarctica.


Assuntos
Migração Animal , Monitorização de Parâmetros Ecológicos/métodos , Baleia Comum/fisiologia , Vocalização Animal , Acústica , Animais , Regiões Antárticas , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Masculino , Nova Zelândia , Estações do Ano , Austrália do Sul
6.
Nat Commun ; 12(1): 3381, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099669

RESUMO

Nutrient amendment diminished bacterial functional diversity, consolidating carbon flow through fewer bacterial taxa. Here, we show strong differences in the bacterial taxa responsible for respiration from four ecosystems, indicating the potential for taxon-specific control over soil carbon cycling. Trends in functional diversity, defined as the richness of bacteria contributing to carbon flux and their equitability of carbon use, paralleled trends in taxonomic diversity although functional diversity was lower overall. Among genera common to all ecosystems, Bradyrhizobium, the Acidobacteria genus RB41, and Streptomyces together composed 45-57% of carbon flow through bacterial productivity and respiration. Bacteria that utilized the most carbon amendment (glucose) were also those that utilized the most native soil carbon, suggesting that the behavior of key soil taxa may influence carbon balance. Mapping carbon flow through different microbial taxa as demonstrated here is crucial in developing taxon-sensitive soil carbon models that may reduce the uncertainty in climate change projections.


Assuntos
Ciclo do Carbono , Mudança Climática , Nutrientes/metabolismo , Microbiologia do Solo , Solo/química , Acidobacteria/genética , Acidobacteria/isolamento & purificação , Acidobacteria/metabolismo , Biodiversidade , Bradyrhizobium/genética , Bradyrhizobium/isolamento & purificação , Bradyrhizobium/metabolismo , Carbono/metabolismo , DNA Bacteriano/isolamento & purificação , Monitorização de Parâmetros Ecológicos/métodos , Previsões/métodos , Fósforo/metabolismo , RNA Ribossômico 16S/genética , Streptomyces/genética , Streptomyces/isolamento & purificação , Streptomyces/metabolismo
7.
PLoS One ; 16(6): e0253213, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34191822

RESUMO

The Salas y Gómez and Nazca ridges are underwater mountain chains that stretch across 2,900 km in the southeastern Pacific and are recognized for their high biodiversity value and unique ecological characteristics. Explorations of deep-water ecosystems have been limited in this region, and elsewhere globally. To characterize community composition of mesophotic and deep-sea demersal fauna at seamounts in the region, we conducted expeditions to Rapa Nui (RN) and Salas y Gómez (SyG) islands in 2011 and Desventuradas Islands in 2013. Remote autonomous baited-cameras were used to conduct stationary video surveys between 150-1,850 m at RN/SyG (N = 20) and 75-2,363 m at Desventuradas (N = 27). Individual organisms were identified to the lowest possible taxonomic level and relative abundance was quantified with the maximum number of individuals per frame. Deployments were attributed with associated environmental variables (temperature, salinity, dissolved oxygen, nitrate, silicate, phosphate, chlorophyll-a, seamount age, and bathymetric position index [BPI]). We identified 55 unique invertebrate taxa and 66 unique fish taxa. Faunal community structure was highly dissimilar between and within subregions both for invertebrate (p < 0.001) and fish taxa (p = 0.022). For fishes, dogfish sharks (Squalidae) accounted for the greatest dissimilarity between subregions (18.27%), with mean abundances of 2.26 ± 2.49 at Desventuradas, an order of magnitude greater than at RN/SyG (0.21 ± 0.54). Depth, seamount age, broad-scale BPI, and nitrate explained most of the variation in both invertebrate (R2 = 0.475) and fish (R2 = 0.419) assemblages. Slightly more than half the deployments at Desventuradas (N = 14) recorded vulnerable marine ecosystem taxa such as corals and sponges. Our study supports mounting evidence that the Salas y Gómez and Nazca ridges are areas of high biodiversity and high conservation value. While Chile and Peru have recently established or proposed marine protected areas in this region, the majority of these ridges lie outside of national jurisdictions and are under threat from overfishing, plastic pollution, climate change, and potential deep-sea mining. Given its intrinsic value, this region should be comprehensively protected using the best available conservation measures to ensure that the Salas y Gómez and Nazca ridges remain a globally unique biodiversity hotspot.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Peixes/fisiologia , Invertebrados/fisiologia , Distribuição Animal , Animais , Chile , Monitorização de Parâmetros Ecológicos/métodos , Ilhas , Oceano Pacífico , Peru , Gravação em Vídeo
8.
PLoS Biol ; 19(5): e3001195, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34010287

RESUMO

Protected areas are the flagship management tools to secure biodiversity from anthropogenic impacts. However, the extent to which adjacent areas with distinct protection levels host different species numbers and compositions remains uncertain. Here, using reef fishes, European alpine plants, and North American birds, we show that the composition of species in adjacent Strictly Protected, Restricted, and Non-Protected areas is highly dissimilar, whereas the number of species is similar, after controlling for environmental conditions, sample size, and rarity. We find that between 12% and 15% of species are only recorded in Non-Protected areas, suggesting that a non-negligible part of regional biodiversity occurs where human activities are less regulated. For imperiled species, the proportion only recorded in Strictly Protected areas reaches 58% for fishes, 11% for birds, and 7% for plants, highlighting the fundamental and unique role of protected areas and their environmental conditions in biodiversity conservation.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitorização de Parâmetros Ecológicos/métodos , Parques Recreativos/tendências , Animais , Biodiversidade , Aves , Ecossistema , Peixes , Atividades Humanas/tendências , Humanos , Parques Recreativos/normas , Plantas
9.
Sci Rep ; 11(1): 8231, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33859208

RESUMO

This proposal investigates the effect of vegetation height and density on received signal strength between two sensor nodes communicating under IEEE 802.15.4 wireless standard. With the aim of investigating the path loss coefficient of 2.4 GHz radio signal in an IEEE 802.15.4 precision agriculture monitoring infrastructure, measurement campaigns were carried out in different growing stages of potato and wheat crops. Experimental observations indicate that initial node deployment in the wheat crop experiences network dis-connectivity due to increased signal attenuation, which is due to the growth of wheat vegetation height and density in the grain-filling and physical-maturity periods. An empirical measurement-based path loss model is formulated to identify the received signal strength in different crop growth stages. Further, a NSGA-II multi-objective evolutionary computation is performed to generate initial node deployment and is optimized over increased coverage, reduced over-coverage, and received signal strength. The results show the development of a reliable wireless sensor network infrastructure for wheat crop monitoring.


Assuntos
Agricultura , Algoritmos , Monitorização de Parâmetros Ecológicos/métodos , Solanum tuberosum/genética , Triticum/genética , Agricultura/instrumentação , Agricultura/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Redes de Comunicação de Computadores , Produtos Agrícolas/genética , Monitorização de Parâmetros Ecológicos/instrumentação , Meio Ambiente , Testes Genéticos/instrumentação , Testes Genéticos/métodos , Reprodutibilidade dos Testes , Solanum tuberosum/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , Tecnologia sem Fio
10.
PLoS One ; 16(3): e0248574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735277

RESUMO

The Dendrocephalus brasiliensis, a native species from South America, is a freshwater crustacean well explored in conservational and productive activities. Its main characteristics are its rusticity and resistance cysts production, in which the hatching requires a period of dehydration. Independent of the species utilization nature, it is essential to manipulate its cysts, such as the counting using microscopes. Manually counting is a difficult task, prone to errors, and that also very time-consuming. In this paper, we propose an automatized approach for the detection and counting of Dendrocephalus brasiliensis cysts from images captured by a digital microscope. For this purpose, we built the DBrasiliensis dataset, a repository with 246 images containing 5141 cysts of Dendrocephalus brasiliensis. Then, we trained two state-of-the-art object detection methods, YOLOv3 (You Only Look Once) and Faster R-CNN (Region-based Convolutional Neural Networks), on DBrasiliensis dataset in order to compare them under both cyst detection and counting tasks. Experiments showed evidence that YOLOv3 is superior to Faster R-CNN, achieving an accuracy rate of 83,74%, R2 of 0.88, RMSE (Root Mean Square Error) of 3.49, and MAE (Mean Absolute Error) of 2.24 on cyst detection and counting. Moreover, we showed that is possible to infer the number of cysts of a substrate, with known weight, by performing the automated counting of some of its samples. In conclusion, the proposed approach using YOLOv3 is adequate to detect and count Dendrocephalus brasiliensis cysts. The DBrasiliensis dataset can be accessed at: https://doi.org/10.6084/m9.figshare.13073240.


Assuntos
Anostraca , Aprendizado Profundo , Monitorização de Parâmetros Ecológicos/métodos , Processamento de Imagem Assistida por Computador/métodos , Animais , Água Doce , América do Sul
11.
PLoS One ; 16(3): e0247536, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33647057

RESUMO

Population assessments of wide-ranging, cryptic, terrestrial mammals rely on camera trap surveys. While camera trapping is a powerful method of detecting presence, it is difficult distinguishing rarity from low detection rate. The margay (Leopardus wiedii) is an example of a species considered rare based on its low detection rates across its range. Although margays have a wide distribution, detection rates with camera traps are universally low; consequently, the species is listed as Near Threatened. Our 12-year camera trap study of margays in protected broadleaf forest in Belize suggests that while margays have low detection rate, they do not seem to be rare, rather that they are difficult to detect with camera traps. We detected a maximum of 187 individuals, all with few or no recaptures over the years (mean = 2.0 captures/individual ± SD 2.1), with two-thirds of individuals detected only once. The few individuals that were recaptured across years exhibited long tenures up to 9 years and were at least 10 years old at their final detection. We detected multiple individuals of both sexes at the same locations during the same survey, suggesting overlapping ranges with non-exclusive territories, providing further evidence of a high-density population. By studying the sparse annual datasets across multiple years, we found evidence of an abundant margay population in the forest of the Cockscomb Basin, which might have been deemed low density and rare, if studied in the short term. We encourage more long-term camera trap studies to assess population status of semi-arboreal carnivore species that have hitherto been considered rare based on low detection rates.


Assuntos
Monitorização de Parâmetros Ecológicos/métodos , Florestas , Panthera/fisiologia , Meio Selvagem , Animais , Comportamento Animal , Belize , Conservação dos Recursos Naturais/métodos , Feminino , Longevidade , Masculino
12.
PLoS One ; 16(2): e0238557, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33626067

RESUMO

Monitoring of marine protected areas (MPAs) is critical for marine ecosystem management, yet current protocols rely on SCUBA-based visual surveys that are costly and time consuming, limiting their scope and effectiveness. Environmental DNA (eDNA) metabarcoding is a promising alternative for marine ecosystem monitoring, but more direct comparisons to visual surveys are needed to understand the strengths and limitations of each approach. This study compares fish communities inside and outside the Scorpion State Marine Reserve off Santa Cruz Island, CA using eDNA metabarcoding and underwater visual census surveys. Results from eDNA captured 76% (19/25) of fish species and 95% (19/20) of fish genera observed during pairwise underwater visual census. Species missed by eDNA were due to the inability of MiFish 12S barcodes to differentiate species of rockfishes (Sebastes, n = 4) or low site occupancy rates of crevice-dwelling Lythrypnus gobies. However, eDNA detected an additional 23 fish species not recorded in paired visual surveys, but previously reported from prior visual surveys, highlighting the sensitivity of eDNA. Significant variation in eDNA signatures by location (50 m) and site (~1000 m) demonstrates the sensitivity of eDNA to address key questions such as community composition inside and outside MPAs. Results demonstrate the utility of eDNA metabarcoding for monitoring marine ecosystems, providing an important complementary tool to visual methods.


Assuntos
Monitoramento Biológico/métodos , Código de Barras de DNA Taxonômico/métodos , DNA Ambiental/análise , Animais , Biodiversidade , California , DNA/análise , Monitorização de Parâmetros Ecológicos/métodos , Ecossistema , Monitoramento Ambiental/métodos , Peixes/genética , Oceano Pacífico
13.
PLoS One ; 16(2): e0239504, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33571210

RESUMO

Monitoring animals in their natural habitat is essential for advancement of animal behavioural studies, especially in pollination studies. Non-invasive techniques are preferred for these purposes as they reduce opportunities for research apparatus to interfere with behaviour. One potentially valuable approach is image-based tracking. However, the complexity of tracking unmarked wild animals using video is challenging in uncontrolled outdoor environments. Out-of-the-box algorithms currently present several problems in this context that can compromise accuracy, especially in cases of occlusion in a 3D environment. To address the issue, we present a novel hybrid detection and tracking algorithm to monitor unmarked insects outdoors. Our software can detect an insect, identify when a tracked insect becomes occluded from view and when it re-emerges, determine when an insect exits the camera field of view, and our software assembles a series of insect locations into a coherent trajectory. The insect detecting component of the software uses background subtraction and deep learning-based detection together to accurately and efficiently locate the insect among a cluster of wildflowers. We applied our method to track honeybees foraging outdoors using a new dataset that includes complex background detail, wind-blown foliage, and insects moving into and out of occlusion beneath leaves and among three-dimensional plant structures. We evaluated our software against human observations and previous techniques. It tracked honeybees at a rate of 86.6% on our dataset, 43% higher than the computationally more expensive, standalone deep learning model YOLOv2. We illustrate the value of our approach to quantify fine-scale foraging of honeybees. The ability to track unmarked insect pollinators in this way will help researchers better understand pollination ecology. The increased efficiency of our hybrid approach paves the way for the application of deep learning-based techniques to animal tracking in real-time using low-powered devices suitable for continuous monitoring.


Assuntos
Monitorização de Parâmetros Ecológicos/métodos , Processamento de Imagem Assistida por Computador/métodos , Gravação em Vídeo/métodos , Algoritmos , Animais , Abelhas/metabolismo , Computadores , Aprendizado Profundo , Ecossistema , Polinização , Software
14.
PLoS One ; 16(2): e0240952, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606695

RESUMO

Intertidal systems are complex and dynamic environments with many interacting factors influencing biochemical characteristics and microbial communities. One key factor are the actions of resident fauna, many of which are regarded as ecosystem engineers because of their bioturbation, bioirrigation and sediment stabilising activities. The purpose of this investigation was to elucidate the evolutionary implications of the ecosystem engineering process by identifying, if any, aspects that act as selection pressures upon microbial communities. A mesocosm study was performed using the well characterised intertidal ecosystem engineers Corophium volutator, Hediste diversicolor, and microphytobenthos, in addition to manual turbation of sediments to compare effects of bioturbation, bioirrigation and stabilisation. A range of sediment functions and biogeochemical gradients were measured in conjunction with 16S rRNA sequencing and diatom taxonomy, with downstream bacterial metagenome function prediction, to identify selection pressures that incited change to microbial community composition and function. Bacterial communities were predominantly Proteobacteria, with the relative abundance of Bacteroidetes, Alphaproteobacteria and Verrucomicrobia being partially displaced by Deltaproteobacteria, Acidobacteria and Chloroflexi as dissolved oxygen concentration and redox potential decreased. Bacterial community composition was driven strongly by biogeochemistry; surface communities were affected by a combination of sediment functions and overlying water turbidity, and subsurface communities by biogeochemical gradients driven by sediment reworking. Diatom communities were dominated by Nitzschia laevis and Achnanthes sp., and assemblage composition was influenced by overlying water turbidity (manual or biogenic) rather than direct infaunal influences such as grazing.


Assuntos
Monitorização de Parâmetros Ecológicos/métodos , Estuários , Sedimentos Geológicos/microbiologia , Microbiota/genética , Acidobacteria/genética , Animais , Bactérias/genética , DNA Bacteriano/genética , Ecossistema , Microbiota/fisiologia , Filogenia , Poliquetos/genética , RNA Ribossômico 16S/genética , Escócia , Análise de Sequência de DNA/métodos , Microbiologia do Solo
15.
PLoS One ; 16(2): e0244787, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33561149

RESUMO

Dall's sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall's sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall's sheep recruitment dynamics.


Assuntos
Reprodução/fisiologia , Ovinos/metabolismo , Neve , Alaska , Animais , Animais Selvagens , Regiões Árticas , Clima , Monitorização de Parâmetros Ecológicos/métodos , Ecossistema , Parques Recreativos/tendências , Estações do Ano , Doenças dos Ovinos/epidemiologia , Temperatura , Tempo (Meteorologia)
16.
PLoS One ; 16(2): e0229703, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33596204

RESUMO

Kelp forests form an important biogenic habitat that responds to natural and human drivers. Global concerns exist about threats to kelp forests, yet long-term information is limited and research suggests that trends are geographically distinct. We examined distribution of the bull kelp Nereocystis luetkeana over 145 years in South Puget Sound (SPS), a semi-protected inner basin in a fjord estuary complex in the northeast Pacific Ocean. We synthesized 48 historical and modern Nereocystis surveys and examined presence/absence within 1-km segments along 452 km of shoreline. Compared to the earliest baseline in 1878, Nereocystis extent in 2017 decreased 63%, with individual sub-basins showing up to 96% loss. Losses have persisted for decades, across a range of climate conditions. In recent decades, Nereocystis predominantly occurred along shorelines with intense currents and mixing, where temperature and nutrient concentrations did not reach thresholds for impacts to Nereocystis performance, and high current speeds likely excluded grazers. Losses predominated in areas with elevated temperature, lower nutrient concentrations, and relatively low current velocities. The pattern of long-term losses in SPS contrasts with stability in floating kelp abundance during the last century in an area of the Salish Sea with greater wave exposure and proximity to oceanic conditions. These findings support the hypothesis that kelp beds along wave-sheltered shorelines exhibit greater sensitivity to environmental stressors. Additionally, shorelines with strong currents and deep-water mixing may provide refugia within sheltered systems.


Assuntos
Conservação dos Recursos Naturais/tendências , Kelp/crescimento & desenvolvimento , Kelp/metabolismo , Colúmbia Britânica , Conservação dos Recursos Naturais/métodos , Monitorização de Parâmetros Ecológicos/métodos , Ecossistema , Estudos Longitudinais , Oceano Pacífico , Temperatura , Washington
17.
Sci Rep ; 11(1): 2982, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536606

RESUMO

To date, little is known about the ecological significance of Comammox (COMplete AMMonia OXidizers) Nitrospira in the water column of freshwater lakes. Water samples collected along depth profiles were used to investigate the distribution of Comammox in 13 lakes characterized by a wide range of physicochemical properties. Several published primers, which target the α-subunit of the ammonia monooxygenase, generated non-specific PCR products or did not amplify target genes from lake water and other habitats. Therefore, a new primer set has been designed for specific detection of Comammox in lakes. The high specificity of the PCR assay was confirmed by sequencing analysis. Quantification of Comammox amoA genes in lake water samples based on droplet digital PCR (ddPCR) revealed very low abundances (not exceeding 85 amoA copies ml-1), which suggest that Comammox is of minor importance for the nitrification process in the water column of the study sites. Surprisingly, samples taken from the sediment/water-interface along an oxygen gradient in dimictic Piburger See showed Comammox abundances three to four magnitudes higher than in the pelagic realm of the lake, which indicates a preference of Comammox to a particle-attached lifestyle.


Assuntos
Amônia/metabolismo , Bactérias/isolamento & purificação , Monitorização de Parâmetros Ecológicos/métodos , Lagos/microbiologia , Reação em Cadeia da Polimerase/métodos , Bactérias/enzimologia , Bactérias/genética , Genes Bacterianos/genética , Sedimentos Geológicos/microbiologia , Ciclo do Nitrogênio , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Filogenia
18.
Nat Commun ; 12(1): 684, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514721

RESUMO

Assessing the seasonal patterns of the Amazon rainforests has been difficult because of the paucity of ground observations and persistent cloud cover over these forests obscuring optical remote sensing observations. Here, we use data from a new generation of geostationary satellites that carry the Advanced Baseline Imager (ABI) to study the Amazon canopy. ABI is similar to the widely used polar orbiting sensor, the Moderate Resolution Imaging Spectroradiometer (MODIS), but provides observations every 10-15 min. Our analysis of NDVI data collected over the Amazon during 2018-19 shows that ABI provides 21-35 times more cloud-free observations in a month than MODIS. The analyses show statistically significant changes in seasonality over 85% of Amazon forest pixels, an area about three times greater than previously reported using MODIS data. Though additional work is needed in converting the observed changes in seasonality into meaningful changes in canopy dynamics, our results highlight the potential of the new generation geostationary satellites to help us better understand tropical ecosystems, which has been a challenge with only polar orbiting satellites.


Assuntos
Monitorização de Parâmetros Ecológicos/métodos , Folhas de Planta/fisiologia , Floresta Úmida , Imagens de Satélites , Brasil , Cor , Fotossíntese , Estações do Ano , Análise Espaço-Temporal
19.
Ecotoxicol Environ Saf ; 208: 111498, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091768

RESUMO

Biomonitoring of heavy metal pollution through the use of biomarkers could be a difficult task since the organisms' physiological changes could shift regarding natural factors (i.e., the season of the year) and due to the anthropogenic pressures of the environment. In the Southwest Atlantic Ocean, where most industrial and developing countries are settled, it is essential to address these concerns to generate information for the stakeholders and monitoring programs that aim to use biochemical biomarkers as early warning signals to detect heavy metal pollution. The present study intended to determinate the heavy metal concentrations in sediments and the hepatopancreas of the crab species Neohelice granulata as well as the ecological risk through the use of biomarkers and geochemical indices in sites with different anthropogenic pressures of the Bahía Blanca estuary (SW Atlantic Ocean) during the warm and cold season. The results showed low to moderate heavy metal pollution in the sediments by Cu with possible effects on the biota in a site with sewage waters' discharges. Except for GST that was explained by Cd, the biomarkers employed were not useful to assess spatial heavy metal pollution, and they might be ruled out by physiological seasonal variations rather than anthropogenic constraints, or another type of pollutants in the area.


Assuntos
Monitorização de Parâmetros Ecológicos , Estuários , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Oceano Atlântico , Braquiúros/metabolismo , Monitorização de Parâmetros Ecológicos/métodos , Biomarcadores Ambientais , Sedimentos Geológicos/química , Humanos , Metais Pesados/metabolismo , Medição de Risco , Estações do Ano , Esgotos/química , América do Sul , Poluentes Químicos da Água/metabolismo
20.
Ann Rev Mar Sci ; 13: 421-443, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32857677

RESUMO

Implementation of marine conservation strategies, such as increasing the numbers, extent, and effectiveness of protected areas (PAs), can help achieve conservation and restoration of ocean health and associated goods and services. Despite increasing recognition of the importance of including aspects of ecological functioning in PA design, the physical characteristics of habitats and simple measures of species diversity inform most PA designations. Marine and terrestrial ecologists have recently been using biological traits to assess community dynamics, functioning, and vulnerability to anthropogenic impacts. Here, we explore potential trait-based marine applications to advance PA design. We recommend strategies to integrate biological traits into (a) conservation objectives (e.g., by assessing and predicting impacts and vulnerability), (b) PA spatial planning (e.g., mapping ecosystem functions and functional diversity hot spots), and (c) time series monitoring protocols (e.g., using functional traits to detect recoveries). We conclude by emphasizing the need for pragmatic tools to improve the efficacy of spatial planning and monitoring efforts.


Assuntos
Organismos Aquáticos/fisiologia , Conservação dos Recursos Naturais/métodos , Monitorização de Parâmetros Ecológicos/métodos , Animais , Biodiversidade , Especificidade da Espécie
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