scholarly journals Performance of a novel system for high-resolution tracking of marine fish societies

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Eneko Aspillaga ◽  
Robert Arlinghaus ◽  
Martina Martorell-Barceló ◽  
Guillermo Follana-Berná ◽  
Arancha Lana ◽  
...  

AbstractRecent advances in tracking systems have revolutionized our ability to study animal movement in the wild. In aquatic environments, high-resolution acoustic telemetry systems make it technically possible to simultaneously monitor large amounts of individuals at unprecedented spatial and temporal resolutions, providing a unique opportunity to study the behaviour and social interactions using a reality mining approach. Despite the potential, high-resolution telemetry systems have had very limited use in coastal marine areas due to the limitations that these environments pose to the transmission of acoustic signals. This study aims at designing and testing a high-resolution acoustic telemetry system to monitor, for the first time, a natural fish population in an open marine area. First, we conducted preliminary range tests and a computer simulation study to identify the optimal design of the telemetry system. Then, we performed a series of stationary and moving tests to characterize the performance of the system in terms of positioning efficiency and precision. Finally, we obtained a dataset corresponding to the movements of 170 concurrently tagged individuals to demonstrate the overall functioning of the system with a real study case of the behaviour of a small-bodied coastal species. Our results show that high-resolution acoustic telemetry systems efficiently generate positional data in marine systems, providing a precision of few meters, a temporal resolution of few seconds, and the possibility of tracking hundreds of individuals simultaneously. Data post-processing using a trajectory filter and movement models proved to be key to achieve a sub-meter positioning precision. The main limitation detected for our system was the restricted detection range, which was negatively affected by the stratification of the water column. Our work demonstrates that high-resolution acoustic telemetry systems are an effective method to monitor the movements of free-ranging individuals at the population level in coastal sites. By providing highly precise positioning estimates of large amounts of individuals, these systems represent a powerful tool to study key ecological processes regarding the social interactions of individuals, including social dynamics, collective movements, or responses to environmental perturbations, and to extend the studies to poorly studied small-sized species or life-stages.

2017 ◽  
Author(s):  
Mariëlle L. van Toor ◽  
Bart Kranstauber ◽  
Scott H. Newman ◽  
Diann J. Prosser ◽  
John Y. Takekawa ◽  
...  

AbstractContextHigh-resolution animal movement data are becoming increasingly available, yet having a multitude of empirical trajectories alone does not allow us to easily predict animal movement. To answer ecological and evolutionary questions at a population level, quantitative estimates of a species’ potential to link patches or populations are of importance.ObjectivesWe introduce an approach that combines movement-informed simulated trajectories with an environment-informed estimate of the trajectories’ plausibility to derive connectivity. Using the example of bar-headed geese we estimated migratory connectivity at a landscape level throughout the annual cycle in their native range.MethodsWe used tracking data of bar-headed geese to develop a multi-state movement model and to estimate temporally explicit habitat suitability within the species’ range. We simulated migratory movements between range fragments, and calculated a measure we called route viability. The results are compared to expectations derived from published literature.ResultsSimulated migrations matched empirical trajectories in key characteristics such as stopover duration. The viability of the simulated trajectories was similar to that of the empirical trajectories. We found that, overall, the migratory connectivity was higher within the breeding than in wintering areas, corresponding to previous findings for this species.ConclusionsWe show how empirical tracking data and environmental information can be fused for meaningful predictions of animal movements throughout the year and even outside the spatial range of the available data. Beyond predicting connectivity, our framework will prove useful for modelling ecological processes facilitated by animal movement, such as seed dispersal or disease ecology.


2020 ◽  
Author(s):  
Xin Hu ◽  
Douglas Walker ◽  
YongLiang Liang ◽  
Matthew Smith ◽  
Michael Orr ◽  
...  

Abstract Complementing the genome with an understanding of the human exposome is an important challenge for contemporary science and technology. Tens of thousands of chemicals are used in commerce, yet cost for targeted environmental chemical analysis limits surveillance to a few hundred known hazards. To overcome limitations which prevent scaling to thousands of chemicals, we developed a single-step express liquid extraction (XLE), gas chromatography high-resolution mass spectrometry (GC-HRMS) analysis and computational pipeline to operationalize the human exposome. We show that the workflow supports quantification of environmental chemicals in small human plasma (200 µL) and tissue (≤ 100 mg) samples. The method also provides high resolution, sensitivity and selectivity for exposome epidemiology of mass spectral features without a priori knowledge of chemical identity. The simplicity of the method can facilitate harmonization of environmental biomonitoring between laboratories and enable population level human exposome research with limited sample volume.


2020 ◽  
pp. 149-168
Author(s):  
Michael J. Fogarty ◽  
Jeremy S. Collie

The dominant focus on production processes in fisheries science sets it apart from other areas of population ecology in which population numbers are the principal currency for analysis. This chapter extends consideration of individual growth and mortality rates provided in earlier chapters to broaden the context for understanding cohort and population processes. A cohort is a group of organisms born within a given time period (e.g. year). How a fish population will respond to harvesting requires not only accurate accounting of its effective reproductive output but an understanding of the relative importance of compensatory mechanisms operating at different points in the life cycle. Recruitment (the number in a cohort surviving to a specified life stage or age) emerges as a dominant component of production at the population level. A dominant theme in this chapter concerns population regulation as embodied in the recruitment process and the high variability in this process.


2020 ◽  
Vol 34 (10) ◽  
pp. 13979-13980
Author(s):  
Wenxi Yu ◽  
Hua Zhou ◽  
Jonathan G. Goldin ◽  
Grace Hyun J. Kim

Domain knowledge acquired from pilot studies is important for medical diagnosis. This paper leverages the population-level domain knowledge based on the D-optimal design criterion to judiciously select CT slices that are meaningful for the disease diagnosis task. As an illustrative example, the diagnosis of idiopathic pulmonary fibrosis (IPF) among interstitial lung disease (ILD) patients is used for this work. IPF diagnosis is complicated and is subject to inter-observer variability. We aim to construct a time/memory-efficient IPF diagnosis model using high resolution computed tomography (HRCT) with domain knowledge-assisted data dimension reduction methods. Four two-dimensional convolutional neural network (2D-CNN) architectures (MobileNet, VGG16, ResNet, and DenseNet) are implemented for an automatic diagnosis of IPF among ILD patients. Axial lung CT images are acquired from five multi-center clinical trials, which sum up to 330 IPF patients and 650 non-IPF ILD patients. Model performance is evaluated using five-fold cross-validation. Depending on the model setup, MobileNet achieved satisfactory results with overall sensitivity, specificity, and accuracy greater than 90%. Further evaluation of independent datasets is underway. Based on our knowledge, this is the first work that (1) uses population-level domain knowledge with optimal design criterion in selecting CT slices and (2) focuses on patient-level IPF diagnosis.


Science ◽  
2020 ◽  
pp. eabe2424 ◽  
Author(s):  
Kaiyuan Sun ◽  
Wei Wang ◽  
Lidong Gao ◽  
Yan Wang ◽  
Kaiwei Luo ◽  
...  

A long-standing question in infectious disease dynamics concerns the role of transmission heterogeneities, driven by demography, behavior and interventions. Based on detailed patient and contact tracing data in Hunan, China we find 80% of secondary infections traced back to 15% of SARS-CoV-2 primary infections, indicating substantial transmission heterogeneities. Transmission risk scales positively with the duration of exposure and the closeness of social interactions and is modulated by demographic and clinical factors. The lockdown period increases transmission risk in the family and households, while isolation and quarantine reduce risks across all types of contacts. The reconstructed infectiousness profile of a typical SARS-CoV-2 patient peaks just before symptom presentation. Modeling indicates SARS-CoV-2 control requires the synergistic efforts of case isolation, contact quarantine, and population-level interventions, owing to the specific transmission kinetics of this virus.


2020 ◽  
pp. 101269022093433 ◽  
Author(s):  
Michael Mutz ◽  
Markus Gerke

Due to the massive spread of a new Coronavirus (SARS-CoV-2), many European governments enacted rules and legislations in order to reduce social interactions and contain the spread of the virus. German authorities put in force a lockdown of all non-essential infrastructure, starting on 22 March 2020. These policies included the closing of sports clubs, fitness centres and community sports grounds. Most federal states prohibited social gatherings of more than two people, thereby further restricting opportunities to play sport and exercise together. The paper addresses how Germans adapted their leisure time sport and exercise (LTSE) activities in this unprecedented situation. Based on survey data representing the adult population (⩾ 14 years, N=1001, data collection 27 March to 6 April 2020), the paper shows a significant decline in LTSE activities at population level. Overall, 31% of Germans reduced their LTSE, while 27% maintained and 6% intensified their LTSE level. A share of 36% was not engaged in LTSE, either before or at the beginning of the lockdown. Younger age groups were more likely to maintain LTSE levels compared with older ones. Comparisons of ‘reducers’ and ‘maintainers/ intensifiers’ indicate that the latter group increased home-based workouts and outdoor endurance sports, while ‘reducers’ did not find adequate substitutes for their sporting routines.


Parasitology ◽  
2020 ◽  
pp. 1-15
Author(s):  
Dana M. Hawley ◽  
Amanda K. Gibson ◽  
Andrea K. Townsend ◽  
Meggan E. Craft ◽  
Jessica F. Stephenson

Abstract An animal's social behaviour both influences and changes in response to its parasites. Here we consider these bidirectional links between host social behaviours and parasite infection, both those that occur from ecological vs evolutionary processes. First, we review how social behaviours of individuals and groups influence ecological patterns of parasite transmission. We then discuss how parasite infection, in turn, can alter host social interactions by changing the behaviour of both infected and uninfected individuals. Together, these ecological feedbacks between social behaviour and parasite infection can result in important epidemiological consequences. Next, we consider the ways in which host social behaviours evolve in response to parasites, highlighting constraints that arise from the need for hosts to maintain benefits of sociality while minimizing fitness costs of parasites. Finally, we consider how host social behaviours shape the population genetic structure of parasites and the evolution of key parasite traits, such as virulence. Overall, these bidirectional relationships between host social behaviours and parasites are an important yet often underappreciated component of population-level disease dynamics and host–parasite coevolution.


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