scholarly journals Projection range of eDNA analysis in marshes: a suggestion from the Siberian salamander (Salamandrella keyserlingii) inhabiting the Kushiro marsh, Japan

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9764
Author(s):  
Daiki Takeshita ◽  
Shigeharu Terui ◽  
Kousuke Ikeda ◽  
Takashi Mitsuzuka ◽  
Maslin Osathanunkul ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Visual Observation ◽  
Freshwater Ecosystems ◽  
Growth Stages ◽  
Sampling Point ◽  
Monitoring Methods ◽  
Breeding Sites ◽  
Breeding Grounds ◽  
Close Range ◽  
Siberian Salamander

Background Freshwater ecosystems are rapidly declining. The Siberian salamander (Salamandrella keyserlingii) which inhabits the Kushiro marsh in Hokkaido, Japan has lost some habitat due to human activity. There are many challenges associated with conventional monitoring methods, including cost, the need for specialist personnel, environmental impact, and ability to detect the presence of this species; thus, we investigated the feasibility of using environmental DNA (eDNA) analysis to detect its presence and identify its breeding grounds. Methods We performed tank experiments to confirm eDNA emission from egg sacs, larvae, and adult Siberian salamanders in the water. We also performed water sampling and visual observation of egg sacs in the Kushiro marsh during the end of the breeding season and the larval season. Results The tank experiments found eDNA emission from all growth stages. It also implied concentrated emissions just after spawning and after hatching, and limited emissions during the incubation phase in egg sacs. We also detected eDNA in the field, likely reflecting the distribution of egg sacs or larvae. Combining this data with visual observations, it was determined that the eDNA results from the field were best explained by the number of egg sacs within 7–10 m of the sampling point. Conclusions The results of this investigation show that the breeding sites and habitats of marshland species can successfully be monitored using eDNA analysis. They also suggest that the eDNA results from the marshes may reflect the biomass that is in close range to the sampling point. These results support the increased use of eDNA analysis in marshes and provide knowledge that could improve the interpretation of future results.

scholarly journals Behavioral Parameters of Planarians (Girardia tigrina) as Fast Screening, Integrative and Cumulative Biomarkers of Environmental Contamination: Preliminary Results

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1077
Author(s):  
Ana M. Córdova López ◽  
Althiéris de Souza Saraiva ◽  
Carlos Gravato ◽  
Amadeu M. V. M. Soares ◽  
Renato Almeida Sarmento
Keyword(s):  
Water Samples ◽  
Feeding Rate ◽  
Anthropogenic Activities ◽  
Behavioral Responses ◽  
Freshwater Ecosystems ◽  
Sampling Point ◽  
Total Chloride ◽  
Fast Screening ◽  
Sampling Points ◽  
The Impact

The present study aims to use behavioral responses of the freshwater planarian Girardia tigrina to assess the impact of anthropogenic activities on the aquatic ecosystem of the watershed Araguaia-Tocantins (Tocantins, Brazil). Behavioral responses are integrative and cumulative tools that reflect changes in energy allocation in organisms. Thus, feeding rate and locomotion velocity (pLMV) were determined to assess the effects induced by the laboratory exposure of adult planarians to water samples collected in the region of Tocantins-Araguaia, identifying the sampling points affected by contaminants. Furthermore, physicochemical and microbiological parameters, as well as the presence of inorganic compounds (dissolved aluminum, total barium, total chloride, dissolved iron, total fluoride, total manganese, nitrates, nitric nitrogen, total sulfate, total zinc) and surfactants, were determined on each specific sampling point. The behavioral biomarkers (feeding rate and pLMV) of the freshwater planarians were significantly decreased when organisms were exposed to water samples from four municipalities (Formoso do Araguaia, Lagoa da Confusão, Gurupi and Porto Nacional), sites of the Tocantins-Araguaia hydrographic region—TAHR. Both behavioral biomarkers decreased up to ~37–39% compared to organisms in ASTM medium only. Our results showed that these behavioral biomarkers can be used for fast screening monitoring of environmental samples of freshwater ecosystems, since a decrease in feeding rate and locomotor activity was observed in sites impacted by anthropogenic activities. However, the absence of effects observed in some sampling points does not represent the absence of contamination, since several other classes of contaminants were not determined. In these negative results, the absence of deleterious effects on behavioral biomarkers might only be indicative that the potential presence of contaminants on such sites does not significantly affect the performance of planarians. This fast screening approach seems to be useful to determine contaminated sites in freshwater ecosystems for biomonitoring purposes. This knowledge will help to develop biomonitoring programs and to decide appropriate sampling sites and analysis.

scholarly journals Challenges for assessing vertebrate diversity in turbid Saharan water-bodies using environmental DNA

Genome ◽  
2018 ◽  
Vol 61 (11) ◽  
pp. 807-814 ◽  
Author(s):  
Bastian Egeter ◽  
Sara Peixoto ◽  
José C. Brito ◽  
Simon Jarman ◽  
Pamela Puppo ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Water Bodies ◽  
Sampling Point ◽  
Sahara Desert ◽  
Turbid Water ◽  
Vertebrate Species ◽  
Sampling Protocol ◽  
Filtering Method ◽  
Small Water ◽  
Human Dna

The Sahara desert is the largest warm desert in the world and a poorly explored area. Small water-bodies occur across the desert and are crucial habitats for vertebrate biodiversity. Environmental DNA (eDNA) is a powerful tool for species detection and is being increasingly used to conduct biodiversity assessments. However, there are a number of difficulties with sampling eDNA from such turbid water-bodies and it is often not feasible to rely on electrical tools in remote desert environments. We trialled a manually powered filtering method in Mauritania, using pre-filtration to circumvent problems posed by turbid water in remote arid areas. From nine vertebrate species expected in the water-bodies, four were detected visually, two via metabarcoding, and one via both methods. Difficulties filtering turbid water led to severe constraints, limiting the sampling protocol to only one sampling point per study site, which alone may largely explain why many of the expected vertebrate species were not detected. The amplification of human DNA using general vertebrate primers is also likely to have contributed to the low number of taxa identified. Here we highlight a number of challenges that need to be overcome to successfully conduct metabarcoding eDNA studies for vertebrates in desert environments in Africa.

scholarly journals Monitoring spawning migrations of potamodromous fish species via eDNA

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bettina Thalinger ◽  
Elisabeth Wolf ◽  
Michael Traugott ◽  
Josef Wanzenböck
Keyword(s):  
Fish Species ◽  
Anthropogenic Impacts ◽  
Environmental Dna ◽  
Signal Strength ◽  
Digital Pcr ◽  
Freshwater Ecosystems ◽  
Non Invasive ◽  
River Stretch ◽  
Daily Discharge ◽  
Invasive Techniques

Abstract Potamodromous fish are considered important indicators of habitat connectivity in freshwater ecosystems, but they are globally threatened by anthropogenic impacts. Hence, non-invasive techniques are necessary for monitoring during spawning migrations. The use of environmental DNA (eDNA) potentially facilitates these efforts, albeit quantitative examinations of spawning migrations remain so far mostly uncharted. Here, we investigated spawning migrations of Danube bleak, Alburnus mento, and Vimba bream, Vimba vimba, and found a strong correlation between daily visual fish counts and downstream eDNA signals obtained from filtered water samples analysed with digital PCR and end-point PCR coupled with capillary electrophoresis. By accounting for daily discharge fluctuations, it was possible to predict eDNA signal strength from the number of migrating fish: first, the whole spawning reach was taken into account. Second, the model was validated using eDNA signals and fish counts obtained from the upper half of the examined river stretch. Consequently, fish counts and their day-to-day changes could be described via an eDNA-based time series model for the whole migration period. Our findings highlight the capability of eDNA beyond delivering simple presence/absence data towards efficient and informative monitoring of highly dynamic aquatic processes such as spawning migrations of potamodromous fish species.

scholarly journals From Mediterranean to Scandinavia—timing and body mass condition in four long distance migrants

Ornis Svecica ◽  
2015 ◽  
Vol 25 (1–2) ◽  
pp. 51-58
Author(s):  
Christos Barboutis ◽  
Leo Larsson ◽  
Åsa Steinholtz ◽  
Thord Fransson
Keyword(s):  
Body Mass ◽  
Arrival Time ◽  
Long Distance ◽  
Breeding Sites ◽  
Swedish Study ◽  
Collared Flycatcher ◽  
Stopover Sites ◽  
Early Arrival ◽  
Breeding Grounds ◽  
Pass Through

In spring, long-distance migrants are considered to adopt a time-minimizing strategy to promote early arrival at breeding sites. The phenology of spring migration was examined and compared between two insular stopover sites in Greece and Sweden for Icterine Warbler, Wood Warbler, Spotted Flycatcher and Collared Flycatcher. All of them migrate due north which means that some proportion of birds that pass through Greece are heading to Scandinavia. The Collared Flycatcher had the earliest and the Icterine Warbler the latest arrival time. The differences in median dates between Greece and Sweden were 3–4 weeks and the passages in Sweden were generally more condensed in time. The average overall speed estimates were very similar and varied between 129 and 137 km/d. In most of the species higher speed estimates were associated with years when birds arrived late in Greece. After crossing continental Europe birds arrive at the Swedish study site with significantly higher body masses compared to when they arrive in Greece and this might indicate a preparation for arriving at breeding grounds with some overload.

scholarly journals Investigation of Dengue Fever Outbreak in a Rural Area of Islamabad, Pakistan: A Case Control Study

2021 ◽  
Author(s):  
Fawad Khalid Khan ◽  
Khurram Shahzad Akram ◽  
Ambreen Chaudhry ◽  
Mir Muhammad Hassan Bullo ◽  
zakir Hussain ◽  
...  
Keyword(s):  
Dengue Fever ◽  
Nonstructural Protein ◽  
Health Department ◽  
Control Measures ◽  
Outbreak Investigation ◽  
Blood Samples ◽  
Breeding Sites ◽  
Nonstructural Protein 1 ◽  
Breeding Grounds ◽  
Ns1 Antigen

Background: In the second week of October 2019, five suspected cases of dengue fever were reported from union council Sohan, Islamabad rural (population 45,747) to the health department, Islamabad Capital Territory (ICT).  Outbreak investigation was conducted with the objectives to identify risk factors and to recommend control measures. Methods: Outbreak investigation was conducted from 17 th October to 25 th November 2019. A case was defined as, “fever and two or more of the following signs/symptoms; headache, retro-orbital pain, joint/bone pain, myalgia and petechial rash with NS1 test (Nonstructural Protein 1) positive during 8 th October to 25 th November 2019 among residents of Sohan”. Age and sex-matched controls were recruited from the same neighborhood. All cases were positive for NS1 antigen. Blood samples from five suspected cases were collected and tested for laboratory confirmation. Results:   A total of 547 households were surveyed and 85 cases were identified. The mean age was 34.4 years + 16.05 (range 3-71 years). The attack rate was 0.19% whereas the most affected age group was the 45-54 years (AR 0.43%). Males were predominantly affected (n=48 56.5%). Among all cases, 32% (n=27)) had stagnant water inside or around their houses (aOR 2.65, CI 1.20-5.83, P= 0.005), 33% (n=28) were using mosquito repellent (aOR 0.35, CI 0.17-0.70, P <0.001), 31% (n=26) used indoor residual spray insecticide (aOR 0.48, CI 0.24-0.97, P =0.041), and 73% (n=62) used full protective clothing (aOR 0.17, CI 0.05-0.58, P <0.001). All five blood samples were tested positive for NS-1 antigen. Conclusion: The presence of accumulated rainwater in pools and empty receptacles around houses acted as breeding grounds for Aedes aegypti mosquitos and was the most probable cause of this outbreak. Following our recommendations, the health department-initiated mosquito breeding sites control activities through residual insecticide spray and advocacy on the use of protective measures against mosquito bites.

scholarly journals PATH PLANNING FOR INDOOR CONTACT INSPECTION TASKS WITH UAVS

2020 ◽  
Vol XLIII-B4-2020 ◽  
pp. 345-351
Author(s):  
L. M. González-deSantos ◽  
J. Martínez-Sánchez ◽  
H. González-Jorge ◽  
P. Arias
Keyword(s):  
Path Planning ◽  
Point Cloud ◽  
Initial Position ◽  
Target Point ◽  
Monitoring Methods ◽  
Planning Algorithm ◽  
Close Range ◽  
Inspection Tasks ◽  
Path Planning Algorithm ◽  
Contact Sensors

Abstract. UAV technology has become a useful tool for the inspection of infrastructures. Structural Health Monitoring methods are already implementing these vehicles to obtain information about the condition of the structure. Several systems based on close range remote sensing and contact sensors have been developed. In both cases, in order to perform autonomous missions in hard accessible areas or with obstacles, a path planning algorithm that calculates the trajectory to be followed by the UAV to navigate these areas is mandatory. This works presents a UAV path planning algorithm developed to navigate indoors and outdoors. This algorithm does not only calculate the waypoints of the path, but the orientation of the vehicle for each location. This algorithm will support a specific UAV-based contact inspection of vertical structures. The required input data consist of a point cloud of the environment, the initial position of the UAV and the target point of the structure where the contact inspection will be performed.

scholarly journals Environmental DNA allows upscaling spatial patterns of biodiversity in freshwater ecosystems

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Luca Carraro ◽  
Elvira Mächler ◽  
Remo Wüthrich ◽  
Florian Altermatt
Keyword(s):  
Spatial Patterns ◽  
Environmental Dna ◽  
Freshwater Ecosystems

scholarly journals Effective removal of the American bullfrog (Lithobates catesbeianus) on a landscape level: long term monitoring and removal efforts in Yosemite Valley, Yosemite National Park

2019 ◽  
Vol 22 (2) ◽  
pp. 617-626 ◽  
Author(s):  
Colleen Kamoroff ◽  
Ninette Daniele ◽  
Robert L. Grasso ◽  
Rebecca Rising ◽  
Travis Espinoza ◽  
...  
Keyword(s):  
Invasive Species ◽  
National Parks ◽  
National Park ◽  
Environmental Dna ◽  
Freshwater Ecosystems ◽  
Yosemite National Park ◽  
American Bullfrog ◽  
Yosemite Valley ◽  
Park Service ◽  
Landscape Level

Abstract Invasive alien species are a major threat to freshwater ecosystems, and American bullfrogs are among the world’s 100 most prominent aquatic invasive species causing negative direct and indirect effect on native aquatic fauna worldwide. Bullfrogs were intentionally introduced into Yosemite Valley, Yosemite National Park in the 1950s where they became well established in the subsequent years. Starting in 2005, the National Park Service (NPS) began bullfrog removal, targeting various life stages using hand, net, and spear techniques. Starting in 2015, the NPS conducted environmental DNA (eDNA) surveys and deployed audio recordings devices to ensure adequate detection of bullfrogs. During the first year of cencerted effort in the Valley in 2005, the NPS removed 86% of all recorded bullfrog. The subsequent decade was spent searching for individuals with lower return on effort. In 2012, the NPS removed the last observed signs of bullfrog breeding, and the last observed bullfrog in 2019. Following removal of the breeding bullfrog population, the NPS began restoration projects for species of special concern. The NPS introduced the federally threatened California red-legged frogs (Rana draytonii) into Yosemite Valley beginning in 2016. This is the first published successful eradication of bullfrogs on a landscape level. National Parks and Monuments often provide refuges for imperiled wildlife and should be managed to remove invasive species. Our work highlights effective bullfrog removal is obtainable and can lead to local recovery of endangered species.

scholarly journals Breeding origins and migratory connectivity at a northern roost of Vaux’s Swift, a declining aerial insectivore

The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Ellis L Smith ◽  
Matthew W Reudink ◽  
Peter P Marra ◽  
Ann E Mckellar ◽  
Steven L Van Wilgenburg
Keyword(s):  
Stable Isotope ◽  
Annual Cycle ◽  
Isotope Analysis ◽  
Vancouver Island ◽  
Cluster Solution ◽  
Migratory Connectivity ◽  
Breeding Sites ◽  
Aerial Insectivores ◽  
Breeding Grounds ◽  
Weak Connectivity

ABSTRACT Populations of Vaux’s Swift (Chaetura vauxi), like those of many aerial insectivores, are rapidly declining. Determining when and where populations are limited across the annual cycle is important for their conservation. Establishing the linkages between wintering and breeding sites and the strength of the connections between them is a necessary first step. In this study, we analyzed 3 stable isotopes (δ13C, δ15N, δ2H) from feathers collected during spring migration from Vaux’s Swifts that perished during a stopover on Vancouver Island, British Columbia, Canada. We previously analyzed claw tissue (grown during winter) from the same individuals, revealing that the swifts likely wintered in 2 or 3 locations/habitats. Here, we used stable isotope analysis of flight feathers presumed to have been grown on, or near, the breeding grounds to determine the likely previous breeding locations and presumed destinations for the swifts. Stable isotope values (δ13C, δ15N, δ2H) showed no meaningful variation between age classes, sexes, or with body size. Surprisingly, ~26% of the birds sampled had feather isotope values that were not consistent with growth on their breeding grounds. For the remaining birds, assigned breeding origins appeared most consistent with molt origins on Vancouver Island. Overall, migratory connectivity of this population was relatively weak (rM = 0.07). However, the degree of connectivity depended on how many winter clusters were analyzed; the 2-cluster solution suggested no significant connectivity, but the 3-cluster solution suggested weak connectivity. It is still unclear whether low migratory connectivity observed for Vaux’s Swift and other aerial insectivores may make their populations more or less vulnerable to habitat loss; therefore, further efforts should be directed to assessing whether aerial insectivores may be habitat limited throughout the annual cycle.

scholarly journals First indications of a sharp population decline in the globally threatened Spoon-billed Sandpiper Eurynorhynchus pygmeus

2002 ◽  
Vol 12 (1) ◽  
pp. 1-18 ◽  
Author(s):  
P. S. Tomkovich ◽  
E. E. Syroechkovski, Jr. ◽  
E. G. Lappo ◽  
C. Zöckler
Keyword(s):  
Local Population ◽  
Population Decline ◽  
Population Estimate ◽  
Rapid Decline ◽  
Northern Coast ◽  
Breeding Sites ◽  
Population Size Estimate ◽  
Breeding Grounds ◽  
Rate Of Decline ◽  
Anadyr Estuary

Spoon-billed Sandpiper Eurynorhynchus pygmeus is classed as globally Vulnerable, based on the only available population estimate, made in 1977, of 2,000–2,800 pairs. Surveys for breeding Spoon-billed Sandpipers were carried out in summer 2000 on the Anadyr estuary coast, the Chukotka autonomous region, Russia. Although six new breeding sites were found, only 16–17 breeding males/pairs were recorded on the northern coast of the Anadyr estuary and five males/pairs on the southern coast and more southerly lagoons. These numbers were much lower than expected, and the species was not recorded in several apparently suitable areas. Four formerly known breeding sites held only one displaying male between them. At no site was there evidence of an increasing or stable local population. Together with other indicative data these suggest a sharp decline in the population of Spoon-billed Sandpiper. The previous population size estimate obviously requires updating, both because there were some incorrect assumptions in the calculations made for the first population estimate, and also due to a recent population decline. It is likely that the current population numbers under 1,000 breeding pairs. Given that the population of this species may be substantially lower than the only previous estimate, and the evidence for a possible rapid decline in its population described in this paper, it is recommended that its IUCN status is changed from Vulnerable to Endangered. No reasons for the apparent rapid rate of decline are evident within the breeding range. “Bottle-necks” should be looked for at migration sites or wintering grounds, but currently, monitoring of the population is only possible on the breeding grounds.

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