Low Anthropogenic Impact Research Articles

К флоре верховья р. Озерное Горло (Чукотка, северные отроги Чуванского хребта)

The survey conducted in August 2021 revealed the main core of the local flora in the upper reaches of the Ozyornoe Gorlo River (southern Chukotka, Anadyr River basin, northern spurs of the Chuvansky Ridge), which had not previously been studied botanically. The peaks in the Chuvansky Ridge system within the research area vary from (900) 1200 to 1300 (1400) m above sea level. On the mountain slopes, cedar elfin loci are spread, higher up transforming into shrubby and lichen tundra. 127 species from 77 genera and 38 families were identified within the flora of the research area. As a consequence of the low anthropogenic impact, the flora here is represented exclusively by the aboriginal fraction, no introduced species identified. Interesting finds, rarely found in adjacent territories, include Poa aff. tuonnachensis, Juncus brachyspathus, Luzula wahlenbergii, Aruncus kamtschaticus, Pyrola minor, Phyllodoce caerulea, Rhododendron camtschaticum, Antennaria angustata, Saussurea oxyodonta, and Taraxacum sibiricum.

Environmental microbiome diversity and stability is a barrier to antimicrobial resistance gene accumulation

When antimicrobial resistant bacteria (ARB) and genes (ARGs) reach novel habitats, they can become part of the habitat’s microbiome in the long term if they are able to overcome the habitat’s biotic resilience towards immigration. This process should become more difficult with increasing biodiversity, as exploitable niches in a given habitat are reduced for immigrants when more diverse competitors are present. Consequently, microbial diversity could provide a natural barrier towards antimicrobial resistance by reducing the persistence time of immigrating ARB and ARG. To test this hypothesis, a pan-European sampling campaign was performed for structured forest soil and dynamic riverbed environments of low anthropogenic impact. In soils, higher diversity, evenness and richness were significantly negatively correlated with relative abundance of >85% of ARGs. Furthermore, the number of detected ARGs per sample were inversely correlated with diversity. However, no such effects were present in the more dynamic riverbeds. Hence, microbiome diversity can serve as a barrier towards antimicrobial resistance dissemination in stationary, structured environments, where long-term, diversity-based resilience against immigration can evolve.

Contrary effects of increasing temperatures on the spread of antimicrobial resistance in river biofilms.

River microbial communities regularly act as the first barrier of defense against the spread of antimicrobial resistance genes (ARGs) that enter environmental microbiomes through wastewater. However, how the invasion dynamics of wastewater-borne ARGs into river biofilm communities will shift due to climate change with increasing average and peak temperatures remains unknown. Here, we aimed to elucidate the effects of increasing temperatures on the naturally occurring river biofilm resistome, as well as the invasion success of foreign ARGs entering through wastewater. Natural biofilms were grown in a low-anthropogenic impact river and transferred to artificial laboratory recirculation flume systems operated at three different temperatures (20°C, 25°C, and 30°C). After 1 week of temperature acclimatization, significant increases in the abundance of the naturally occurring ARGs in biofilms were detected at higher temperatures. After this acclimatization period, biofilms were exposed to a single pulse of wastewater, and the invasion dynamics of wastewater-borne ARGs were analyzed over 2 weeks. After 1 day, wastewater-borne ARGs were able to invade the biofilms successfully with no observable effect of temperature on their relative abundance. However, thereafter, ARGs were lost at a far increased rate at 30°C, with ARG levels dropping to the initial natural levels after 14 days. Contrary to the lower temperatures, ARGs were either lost at slower rates or even able to establish themselves in biofilms with stable relative abundances above natural levels. Hence, higher temperatures come with contrary effects on river biofilm resistomes: naturally occurring ARGs increase in abundance, while foreign, invading ARGs are lost at elevated speeds.IMPORTANCEInfections with bacteria that gained resistance to antibiotics are taking millions of lives annually, with the death toll predicted to increase. River microbial communities act as a first defense barrier against the spread of antimicrobial resistance genes (ARGs) that enter the environment through wastewater after enrichment in human and animal microbiomes. The global increase in temperature due to climate change might disrupt this barrier effect by altering microbial community structure and functions. We consequently explored how increasing temperatures alter ARG spread in river microbial communities. At higher temperatures, naturally occurring ARGs increased in relative abundance. However, this coincided with a decreased success rate of invading foreign ARGs from wastewater to establish themselves in the communities. Therefore, to predict the effects of climate change on ARG spread in river microbiomes, it is imperative to consider if the river ecosystem and its resistome are dominated by naturally occurring or invading foreign ARGs.

Mercury content and elemental composition of fruticose lichens from Nahuel Huapi National park (Patagonia, Argentina): Time trends in transplanted and in situ grown thalli

Lichens have a unique structure involving the symbiosis of fungus and algae and can grow on almost any type of substrate. They absorb gases, water, nutrients and pollutants through their cortex, and thus are good indicators of environmental processes, enabling the biomonitoring of environmental pollutants. These organisms are widely distributed; however, as certain species do not occur in some areas, transplants are commonly used to monitor air pollution. In this study, transplants of the fruticose species Protousnea magellanica were set up at the EMMA Station (Global Mercury Observation System, GMOS) located at a suburban site of San Carlos de Bariloche city within Nahuel Huapi National Park (North Patagonia, Argentina). The transplants were used to assess the uptake of certain elements, particularly the accumulation of mercury. Periodic samplings of the transplanted species P. magellanica and the naturally occurring Usnea pusilla were performed concurrently at the experimental site over 483 days of experimental exposure. The elemental composition and concentration of the thalli of these species were determined by Neutron Activation Analysis in a nuclear reactor. Atmospheric mercury concentration (Gaseous Elemental Mercury, GEM) was monitored at the EMMA Station by an automated cold vapor atomic fluorescence system (Tekran 2537B). Mercury concentrations in the lichens were at least three orders of magnitude higher than atmospheric mercury levels (0.80–0.94 ng/m3, ppt), highlighting the accumulation capacity of these organisms. Concentrations found in P. magellanica thalli (0.080–0.327 μg/g dry weight, ppm) lay within the range of values reported previously in lichens from the Nahuel Huapi National Park with low anthropogenic impact. During experimental exposure both lichen species displayed the same trend in Hg content. Total Hg increased from T0 to T1 (day 25) and then decreased up to approximately T4 (day 385). In U. pusilla, the positive relationship between Hg content and lithophilic elements such as La, suggested preferential Hg uptake from airborne particles (deposited dust).

Composition and Flux of Dissolved and Particulate Carbon and Nitrogen in the Lower Tocantins River

AbstractThe Tocantins River contributes ∼5% of the total flux of water to the Amazon River plume in the Atlantic Ocean. Here, we evaluate monthly variability in the composition and abundance of carbon, nitrogen, and suspended sediment in the lower reaches of the Tocantins River from 2014 to 2016. Dissolved organic carbon concentrations generally increased during periods of high discharge and are ∼1.5 times lower than average concentrations at the mouth of the Amazon River. Dissolved inorganic carbon similarly increased during periods of high discharge. Total dissolved nitrogen and individual nitrogen species followed a similar temporal pattern, increasing during high water. predominated the dissolved inorganic nitrogen pool, followed by , and , characteristic of environments with a relatively low anthropogenic impact. Dissolved fractions represented 92% of the total carbon exported and 78% of the total nitrogen exported. The suspended particulate sediment flux was 2.72 × 106 t yr−1, with fine suspended sediment dominating (71.3%). Concentrations of carbon relative to nitrogen indicate a primarily terrigenous source of organic matter and CO2 derived from in situ respiration of this material during the rainy season and a primarily algal/bacterial source of organic matter during the dry season. Considering past estimates of dissolved carbon and nitrogen fluxes from the Amazon River to the Atlantic Ocean, the Tocantins River contributes 3% and 3.7% to total fluxes to the Amazon River plume region, respectively. While this contribution is relatively small, it may be influenced by future changes to the basin's land use and hydrology.

Extent of anthropogenic influence on groundwater quality and human health-related risks: an integrated assessment based on selected physicochemical characteristics

Majority of people living on earth rely on groundwater as their primary supply of water for daily needs. However, human activities continuously threaten this natural resource. In an attempt to unravel the extent of impact of human-related activities on groundwater physicochemical characteristics in Nnewi and Awka urban clusters (Nigeria), several techniques were integrated in this study. Groundwater samples were warm and acidic in nature. Concentrations of SO4 2-, NO3 -, PO4 3-, Cl-, HCO3 -, Ca2+, Mg2+, Na+, and K+ were within set benchmarks. Water nutrient pollution index (ranging from 0.060-0.745), nitrate pollution index (varying between -0.999 and -0.790), and water pollution index (ranging from 0.057-0.630) estimated the extent of anthropogenic contamination and showed low anthropogenic impact on the groundwater physicochemical characteristics. The health risks due to the ingestion and skin absorption of the nitrate-contaminated water computed for six age groups (6-12 months, 5-10 years, 10-15 years, 15-20 years, 20-60 years, and > 60 years) showed health risk values that were < 1, implying low chronic health risks to humans. The cumulative total health hazard index ranged between 0.006 and 0.787 with a mean value of 0.167. Chemometric analyses and geochemical plots revealed the relationships between the variables and contamination sources. Chadha’s plot showed that 55% of the samples were Ca2+-Mg2+-Cl- waters, predominating over Na+-Cl- and Ca2+-Mg2+-HCO3 - waters. Bivariate and multivariate geochemical plots also indicated low anthropogenic impact. Furthermore, principal component analysis and R-type hierarchical clustering confirmed that the groundwater chemistry and quality were mostly influenced by geogenic processes than human-related acts. Conclusively, the extent of anthropogenic influence on the groundwater physicochemical characteristics is low. These findings would be useful in future monitoring of groundwater in both urban clusters.

Landscape features control river's confluences water quality and tributary fish composition

AbstractRivers networks represent hierarchical dendritic habitats within terrestrial landscapes and differences in connectivity and land use influence dispersal, and consequently biodiversity patterns. We, therefore, measured variation in water chemistry and fish abundance and related these to a number of landscape characteristics (e.g., wetland, urban, wooded, and agricultural) in the River Klarälven and its 30 permanently flowing tributaries. We hypothesized that these environmental attributes would differ between tributary and main stem habitat and that these differences would be driven by landscape attributes including land use. We found considerable intertributary variation in temperature and nutrient levels, and between the tributaries and the main stem. Generally, water temperature was lower in the tributaries, whereas nutrient levels were higher in the tributaries. The lower water temperature has implications for coldwater fishes, and we found two fishes, burbot and lamprey, associated with coldwater tributaries. We also found an inverse relationship between water quality and anthropogenic land use. Protecting tributaries with low anthropogenic impact will likely become increasingly important with ongoing global warming as they can function as thermal refugia for coldwater fishes. Hence, this study underscores the need to evaluate water courses at regional scales to identify spatial refuges and ensure connectivity.

Marine Pollutant Tributyltin Affects DNA Methylation and Fitness of Banded Murex (Hexaplex trunculus) Populations

Banded murex, Hexaplex trunculus, is a marine gastropod whose reproductive fitness can be severely affected by very low concentrations of antifouling compound tributyltin (TBT). TBT has strong xenoandrogen impacts on snails, causing the development of imposex (e.g., the superimposition of male sexual characteristic in females), thereby affecting the fitness of entire populations. TBT is also known as a DNA-demethylating agent and an obesogenic factor. The aim of this study was to unravel the interactions between TBT bioaccumulation, phenotypic responses, and epigenetic and genetic endpoints in native populations of H. trunculus. Seven populations inhabiting environments along the pollution gradient were sampled in the coastal eastern Adriatic. These included sites of intense marine traffic and boat maintenance activity and sites with low anthropogenic impact. Populations inhabiting intermediately and highly polluted sites exhibited higher TBT burdens, higher incidences of imposex, and higher wet masses of snails than populations in lowly polluted sites. Other morphometric traits and cellular biomarker responses did not show clear differentiation among populations in relation to marine traffic/pollution intensity. An analysis of methylation sensitive amplification polymorphism (MSAP) revealed environmentally driven population differentiation and higher epigenetics than genetic within-population diversity. Moreover, decreases in genome-wide DNA methylation coincided with the imposex level and snail mass, suggesting an epigenetic background of the animal phenotypic response.

Long-Term Dynamics of the Avifauna in the North of Western Siberia

Changes in the avifauna of the three large regions of the north of the Yamalo-Nenets Autonomous Okrug (Russia), the Lower Ob River region, the floodplain of the Lower Ob, and the Yamal Peninsula, have been analyzed for a period of more than 60 years. The analysis is based on relative estimates of the number of species on a 4-point scale; cases of significant shifts in the species ranges also have been considered. It is shown that avifaunae in the long term are highly dynamic formations, the process of their changes is of a permanent nature. Its scale is about half of the species composition for 60 years and its directions vary greatly in different regions, depending on the degree of anthropogenic transformation of the territory. Areas with a relatively low anthropogenic impact (the Lower Ob and the Ob floodplain) are characterized by the predominance of the positive trends, mainly expressed in the appearance of new species. Many of them (more than 25% of the modern species composition) have been detected in the Ob floodplain, which indicates the canalization of the penetration process for new species to the north. The Yamal Peninsula region, where the anthropogenic impact associated with domestic reindeer overgrazing is high, is characterized by the predominance of the negative trends in the form of a decrease in the number of typical tundra species.

Can a Protected Area Help Improve Fish Populations under Heavy Recreation Fishing?

Freshwater protected areas are designated parts of the inland waters that restrict human activities. They were created as a mechanism to combat the decline of fauna and flora of the world. Some authors have questioned their actual effectiveness in terms of the purpose of protecting endangered fauna and flora. We conducted an experiment in Lipno reservoir in the Czech Republic to evaluate the impact of protection against angling pressure on the fish community. We selected data from two years of gill netting and analyzed the difference between areas of low anthropogenic impact (LAI) and those of high anthropogenic impact (HAI) in terms of abundance, biomass, standard length, and diversity indices. Three groups of fish were found to prefer protected areas with low anthropogenic pressure: 1. YOY (Young-of-the-year) perch (Perca fluviatilis), the dominant of the young-of-the-year fish community. 2. Pike (Esox lucius), wels catfish (Silurus glanis) and rudd (Scardinius erythrophthalmus), which were not found in HAI areas at all. 3. Larger individuals of pikeperch (Stizostedion lucioperca), which survived better in LAI areas. Some factors may affect LAI, such as illegal poaching or setting out food bait to attract the fish outside. Another factor that can be considered is the migration of fish, either to forage or to reproduce, since the LAI areas are open to the reservoir. The areas of LAI act as protective habitats for heavily exploited predatory fish species and increase fish diversity indexes. The example of the protected and low-impact areas of Lipno should be followed in other water bodies with high fishing pressure and anthropogenic impact.

Population Structure of Pyrola chlorantha (Family Ericaceae) at the Southern Range Margin (Samara Region, Russia)

The population structure of endangered species is one of the main criteria for assessing their state in their habitats. Representatives of the Ericaceae family are sensitive to environmental changes, including anthropogenic pressure; thus, they are considered the indicator species in assessing phytocenose stability. The population structure and density of the threatened species green-flowered wintergreen, Pyrola chlorantha Sw., have been described at the southern range margin (south-east of the European part of Russia, Samara Region). The observations were performed here in 2006–2021, and the main parameters of the age and spatial structure of P. chlorantha populations were revealed for the first time. Green-flowered wintergreen populations were studied at monitoring study sites and at temporarily established study plots. A bush part (ramet) was set as a counting unit. In total, 27 sub-populations were surveyed, with 1520 individuals registered. The age structure of populations was characterized using common demographic indicators: the recovery index and the population age index. The age structure of the population was associated with the efficiency of both vegetative and seed reproduction. Generally, the share of pre-generative individuals was 32.3%, generative, 66.9%, and senile, 1.8%. The studied populations were stable due to low anthropogenic impact at the growth sites.

Study of antibiotic resistance in freshwater ecosystems with low anthropogenic impact

This study aimed to investigate the bacterial diversity and the background level of antibiotic resistance in two freshwater ecosystems with low anthropogenic impact in order to evaluate the presence of natural antimicrobial resistance in these areas and its potential to spread downstream. Water samples from a pre-Alpine and an Apennine river (Variola and Tiber, respectively) were collected in three different sampling campaigns and bacterial diversity was assessed by 16S sequencing, while the presence of bacteria resistant to five antibiotics was screened using a culturable approach.Overall bacterial load was higher in the Tiber River compared with the Variola River. Furthermore, the study revealed the presence of resistant bacteria, especially the Tiber River showed, for each sampling, the presence of resistance to all antibiotics tested, while for the Variola River, the detected resistance was variable, comprising two or more antibiotics. Screening of two resistance genes on a total of one hundred eighteen bacterial isolates from the two rivers showed that blaTEM, conferring resistance to β-lactam antibiotics, was dominant and present in ~58 % of isolates compared to only ~9 % for mefA/E conferring resistance to macrolides. Moreover, β-lactam resistance was detected in various isolates showing also resistance to additional antibiotics such as macrolides, aminoglycosides and tetracyclines. These observations would suggest the presence of co-resistant bacteria even in non-anthropogenic environments and this resistance may spread from the environment to humans and/or animals.

Effectiveness of Morelet's crocodile as a bioindicator of metal pollution and metallothionein response to spatial variations of metal exposure

• Significant differences for mercury between the factors tissue:site were detected. • Significant differences for zinc between the factors tissue:site were detected. • Metallothioneins in blood plasma were detected in all sites but in erythrocytes detection frequency was lower than 20%. Several studies have assessed the potential of crocodylians as bioindicators of environmental contamination. In this study, the Morelet's crocodile ( Crocodylus moreletii ) was used as a bioindicator of metal pollution across five locations in southeastern Mexico classified as having high, medium, and low anthropogenic impact. Total length and sex were determined for each animal and concentrations of metals and metallothioneins (MTs) were determined by using non-destructive tissues. Mercury (Hg) concentrations in crocodile blood and scutes generally exhibited a decreasing pattern from the higher impacted site to the lower impacted site ( x 2 (14) = 185.42, p < 0.001), suggesting that concentrations in these samples are sensitive enough to identify difference in the bioavailability of Hg within crocodile populations. The highest concentrations were detected in scutes from Laguna Guerrero (Hg = 0.60 ± 0.217 µg/g w.w.) and Nichupté-Bojorquez (Cd = 14.99 ± 2.95 µg/g w.w., Cu = 58.66 ± 11.29 µg/g w.w., Zn = 80.86 ± 80.54 µg/g w.w.). MTs in blood plasma were detected at all sites (27.48 ± 4.78 µg/mL) but was low in erythrocytes detection frequency, suggesting this latter fraction may not be useful for MTs analysis. In general, our study supports the utility of crocodiles as bioindicators of xenobiotic metal pollution. However, it is necessary for such studies to perform assays for specific MT isoforms and the effective concentrations of metals bound to this protein, and to determine metal concentrations in multiple environmental matrices from the sites under evaluation.

Biogeographical Patterns of Bacterial Communities and Their Antibiotic Resistomes in the Inland Waters of Southeast China.

ABSTRACTFreshwater ecosystems are important sources of drinking water and provide natural settings for the proliferation and dissemination of bacteria and antibiotic resistance genes (ARGs). However, the biogeographical patterns of ARGs in natural freshwaters and their relationships with the bacterial community at large scales are largely understudied. This is of specific importance because data on ARGs in environments with low anthropogenic impact is still very limited. We characterized the biogeographical patterns of bacterial communities and their ARG profiles in 24 reservoirs across southeast China using 16S rRNA gene high-throughput sequencing and high-throughput-quantitative PCR, respectively. We found that the composition of both bacterial communities and ARG profiles exhibited a significant distance-decay pattern. However, ARG profiles displayed larger differences among different water bodies than bacterial communities, and the relationship between bacterial communities and ARG profiles was weak. The biogeographical patterns of bacterial communities were simultaneously driven by stochastic and deterministic processes, while ARG profiles were not explained by stochastic processes, indicating a decoupling of bacterial community composition and ARG profiles in inland waters under relatively low-human-impact at a large scale. Overall, this study provides an overview of the biogeographical patterns and driving mechanisms of bacterial community and ARG profiles and could offer guidance and reference for the control of ARGs in drinking water sources.IMPORTANCE Antibiotic resistance has been a serious global threat to environmental and human health. The “One Health” concept further emphasizes the importance of monitoring the large-scale dissemination of ARGs. However, knowledge about the geographical patterns and driving mechanisms of bacterial communities and ARGs in natural freshwater environments is limited. This study uncovered the distinct biogeographical patterns of bacterial communities and ARG profiles in inland waters of southeast China under low-anthropogenic impact at a large scale. This study improved our understanding of ARG distribution in inland waters with emphasis on drinking water supply reservoirs, therefore providing the much-needed baseline information for future monitoring and risk assessment of ARGs in drinking water resources.

Water quality analysis based on phytoplankton and metal indices: a case study in the Sauce Grande River Basin (Argentina).

The increasing landscape alterations due to anthropogenic activities is of global concern since it affects aquatic ecosystems, often resulting in compromise of the ecological integrity and the water quality. In this sense, the evaluation, monitoring, and prediction of the aquatic ecosystem quality becomes an important research subject. This study presents the first integrated water quality assessment of the Sauce Grande River Basin, in Argentina, based on the spatial distribution of the phytoplankton community, the physicochemical parameters, and the metal concentrations (Cd, Cu, Cr, Fe, Mn, Ni, Pb, and Zn) found in the particulate fraction. According to the trophic indices and the phytoplankton abundance, composition, and diversity, the water quality showed significant deterioration in the lower basin after the Sauce Grande lake. The trophic state index indicated that water was oligotrophic in over 75% of the sampling sites, increasing downstream, where two sites were characterized as mesotrophic, and one described as hypertrophic. The phytoplankton community was dominated by diatoms in zones with low anthropogenic impact and conductivity, whereas high densities of Euglenophyta, Chlorophyta, and Cyanobacteria were found in the middle-lower basin, associated with higher organic matter and eutrophication. The conductivity, turbidity, and most metal concentrations also increased towards the downstream area, even exceeding recommended levels for the metals Cu, Cr, Mn, and Pb in the middle and lower reaches of the basin (Cu: 3.5µg L-1; Cr: 2.4µg L-1; Pb: 1.2µg L-1; Mn 170µg L-1). This study generates a database for the water quality of the Sauce Grande River Basin and sets an example of how the water quality varies along a basin that crosses different topographic environments, land covers, and anthropogenic influences.

Epiphytic foraminifers as indicators of heavy-metal pollution in Posidonia oceanica seagrass meadows

Because of their toxicity, persistence and difficult biodegradability heavy metals are one of the most significant pollutants in marine environments, including seagrass meadows. Epiphytic foraminifers are conspicuous in the Posidonia oceanica meadows and can be utilized as cost-effective bioindicators. To evaluate the ecological conditions of P. oceanica meadows around the Balearic Islands four indices based on benthic foraminiferal assemblages, such as, the modified FORAM Index (FI’), the “Long vs Short life span” index (ILS), the Foram Stress Index (FSI), and Shannon-Weaver index (H’), were calculated. High index values for all sampling sites with different anthropogenic activities indicated a good ecological status of the seagrass. In contrast, the proportion of abnormal foraminiferal tests (FAI), based on morphological analysis, was variable among the study sites and reach very high abundances in areas with a priori low anthropogenic impact. Although there is not a univocal cause-effect pattern between the occurrence of deformed individuals and heavy metal pollution (such as Cu, Zn, Cd, Pb, Co, Ni, As and Sn), abnormal growth forms were significantly more abundant in sites where the tests contained higher concentrations of trace elements, and certain deformities (occurrence of protuberances and supernumerary chambers) seemed to be associated with specific pollutants (Zn, Ni and As). The disparity between the foraminiferal biotic indices and the percentage of aberrant forms associated with the heavy metal uptake can be explained by differences in the type of environmental impact and the mineral composition of the foraminiferal tests. Thus, the use of foraminifera as bioindicators, combining different approaches such as ecological indices, quantification of abnormal growth patterns and geochemical analysis of their tests, are very helpful in determining the health of seagrass meadows ecosystems. The indices are proxies to show dominant conditions over a large area, whereas the morphological and geochemical analysis of the foraminiferal tests shows very localized but long-lasting impacts with sublethal effects.

Use of resonant cavity spectrometer (CRDS) for methane detection in impacted and non-impacted areas

Methane is one of the main greenhouse gases, impacting a lot on the radioactive forcing, contributing a lot to global warming. Identifying methane generating sources are important in mitigating actions, mainly of anthropic origin. In this work, methane emissions were observed in two distinct areas, one with low anthropogenic impact and the other with high industrial activity. A resonant cavity spectrometer (CRDS) was used to analyze methane concentrations during the months of June and July/2019 in the city of Itanhém and in the months of September, October and January of 2019 in the city of Cubatão.

Behavioral effects of wolf presence on moose habitat selection: testing the landscape of fear hypothesis in an anthropogenic landscape

Landscape of fear refers to the spatial variation in prey perception of predation risk, that under certain conditions, may lead to changes in their behavior. Behavioral responses of prey in relation to large carnivore predation risk have mainly been conducted in areas with low anthropogenic impact. We used long-term data on the distribution of moose in different habitat types in a system characterized by intensive management of all three trophic levels (silviculture, harvest of wolves and moose) to study effects on moose habitat selection resulting from the return of an apex predator, the wolf. We assumed that coursing predators such as wolves will cause an increased risk for moose in some habitat types and tested the hypotheses that moose will avoid open or young forest habitats following wolf establishment. After wolf recolonization, moose reduced their use of one type of open habitat (bog) but there was neither change in the use of the other open habitat type (clear-cut), nor in their use of young forest. Wolf establishment did not influence the use of habitat close to dense habitat when being in open habitats. Thus, the effect of wolves varied among habitat types and there was no unidirectional support for a behavioral effect of wolves’ establishment on moose habitat use. Human-driven habitat heterogeneity, concentration of moose forage to certain habitat types, and the effects of a multiple predator guild on moose may all contribute to the results found. We conclude that the landscape of fear is likely to have weak ecological effects on moose in this system.

Evaluation of Aliphatic Hydrocarbons in Surface Sediments of Lagoa Mirim (RS, Brazil).

In this study, the hydrocarbons (HCs) levels in sediments from Lagoa Mirim, situated in the south of Brazil, were verified. The methodology brought together stages of pre-sonification, soxhlet extraction, and determination by gas chromatography coupled with mass spectrometry (GC/MS). Ten sample points were evaluated where ∑n-alkanes varied between 1.46µg kg-1 ± 4.0% and 10.10µg kg-1 ± 17.6%. Diagnostic indexes were calculated, being: Carbon Preferential Index (CPI), terrestrial/aquatic ratio (TAR), unresolved complex mixture (UCM), UCM/∑n-alkanes ratio, and n-alkane ratio with Low molecular weight hydrocarbon and High molecular weight hydrocarbons (HMW/LMW). In general, the results of this study indicate a low anthropogenic impact in the environment.

Wide-scope screening of pharmaceuticals, illicit drugs and their metabolites in the Amazon River

Only a limited number of households in the Amazon are served by sewage collection or treatment facilities, suggesting that there might be a significant emission of pharmaceuticals and other wastewater contaminants into freshwater ecosystems. In this work, we performed a wide-scope screening to assess the occurrence of pharmaceuticals, illicit drugs and their metabolites in freshwater ecosystems of the Brazilian Amazon. Our study included 40 samples taken along the Amazon River, in three of its major tributaries, and in small tributaries crossing four important urban areas (Manaus, Santarém, Macapá, Belém). More than 900 compounds were investigated making use of target and suspect screening approaches, based on liquid chromatography coupled to high-resolution mass spectrometry with ion mobility separation. Empirical collision-cross section (CCS) values were used to help and confirm identifications in target screening, while in the suspect screening approach CCS values were predicted using Artificial Neural Networks to increase the confidence of the tentative identification. In this way, 51 compounds and metabolites were identified. The highest prevalence was found in streams crossing the urban areas of Manaus, Macapá and Belém, with some samples containing up to 30 - 40 compounds, while samples taken in Santarém showed a lower number (8 - 11), and the samples taken in the main course of the Amazon River and its tributaries contained between 1 and 7 compounds. Most compounds identified in areas with significant urban impact belonged to the analgesics and antihypertensive categories, followed by stimulants and antibiotics. Compounds such as caffeine, cocaine and its metabolite benzoylecgonine, and cotinine (the metabolite of nicotine), were also detected in areas with relatively low anthropogenic impact and showed the highest total prevalence. This study supports the need to improve the sanitation system of urban areas in the Brazilian Amazon and the development of follow-up studies aimed at quantifying exposure levels and risks for Amazonian freshwater biodiversity.