scholarly journals Acoustic telemetry detection probability and location accuracy in a freshwater wetland embayment

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Nathan D. Stott ◽  
Matthew D. Faust ◽  
Christopher S. Vandergoot ◽  
Jeffrey G. Miner
Keyword(s):  
Detection Probability ◽  
Acoustic Telemetry ◽  
Large Scale ◽  
Open Water ◽  
Tidal Marshes ◽  
Freshwater Wetland ◽  
Location Error ◽  
Positional Accuracy ◽  
Detection Range ◽  
Transmitter Power

Abstract Background In recent years, large-scale acoustic telemetry observation networks have become established globally to gain a better understanding of the ecology, movements and population dynamics of fish stocks. When studying a species that uses different habitats throughout its life history difficulty may arise where acoustically suboptimal habitats are used, such as shallow, vegetated areas. To test the feasibility of active tracking in these acoustically suboptimal habitats, we quantified detection probability and location error as a function of several environmental variables with two transmitter types in a shallow freshwater embayment. Results When placed in nearshore areas (< 1 m deep), the higher-powered transmitter (158 dB) had significantly greater detection probability than the lower-powered transmitter (152 dB). For both transmitter types, detection probability declined at 200 m; however, at the 100 m distance the higher-powered transmitter had greater than 50% detection probability per ping cycle (50.4%) while the lower-powered transmitter was substantially less (29.4%). Additionally, detection probability increased when the transmitter was deployed within sparse, senescent Phragmites spp. vegetation (14%). Estimated positional accuracy of transmitters deployed at known locations (location error) was variable (error range: 13–259 m), and was generally higher for the more powerful transmitter. Location error was minimized when the lower-powered transmitter was located near softened shoreline areas compared to near man-made armored shorelines (i.e., rip-rap). Conclusion While benefits exist for maximizing transmitter power (e.g., increased detection range in open-water environments), use of a lower-powered transmitter may be advantageous for active tracking specific locations of fish inhabiting shallow water environments, such as in estuarine tidal marshes and shallow wetlands. Thus, when planning acoustic telemetry studies, researchers should conduct site-specific preliminary detection probability/location error experiments to better understand the utility of acoustic telemetry to investigate fish movements in acoustically suboptimal conditions.

Optimising the design of large-scale acoustic telemetry curtains

2017 ◽  
Vol 68 (8) ◽  
pp. 1403 ◽  
Author(s):  
Andre Steckenreuter ◽  
Xavier Hoenner ◽  
Charlie Huveneers ◽  
Colin Simpfendorfer ◽  
Marie J. Buscot ◽  
...  
Keyword(s):  
High Frequency ◽  
Acoustic Telemetry ◽  
Large Scale ◽  
National Scale ◽  
Detection Range ◽  
Animal Tracking ◽  
Acoustic Networks ◽  
Acoustic Receiver ◽  
Receiver Arrays ◽  
The Cost

Broad-scale acoustic telemetry networks are being established worldwide. The 10-year anniversary of the Integrated Marine Observing System’s Animal Tracking Facility provided the opportunity to assess the efficiency of one of the first national-scale acoustic telemetry networks. Acoustic networks are comprised of acoustic receiver arrays that detect high-frequency transmitters attached to animals that pass within detection range. Herein we assessed the efficiency of eight curtains to detect passing animals by calculating the standardised mean number of detections and transmitters detected at each station. The aim was to determine how many receivers could be decommissioned from each curtain while maintaining its integrity (i.e. detection of all species passing the array). Pivotal locations were defined as the furthest station at which all species would still be detected and where at least 75% of the detections and transmitters would still be detected. By applying these criteria, we were able to improve the cost-effectiveness of our network significantly, reducing the number of stations from 132 to 85 (64% of the original network), yet still retaining 84% of total detections, 86% of transmitters and 100% of detected species. The present study provides a useful framework for refining acoustic telemetry networks.

scholarly journals Hydrology influences breeding time in the white-throated dipper

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Anna L. K. Nilsson ◽  
Thomas Skaugen ◽  
Trond Reitan ◽  
Jan Henning L’Abée-Lund ◽  
Marlène Gamelon ◽  
...  
Keyword(s):  
Climate Change ◽  
River Discharge ◽  
Large Scale ◽  
Time Window ◽  
River System ◽  
Open Water ◽  
Local Conditions ◽  
Environmental Indices ◽  
Groundwater Levels ◽  
Breeding Time

Abstract Background Earlier breeding is one of the strongest responses to global change in birds and is a key factor determining reproductive success. In most studies of climate effects, the focus has been on large-scale environmental indices or temperature averaged over large geographical areas, neglecting that animals are affected by the local conditions in their home ranges. In riverine ecosystems, climate change is altering the flow regime, in addition to changes resulting from the increasing demand for renewable and clean hydropower. Together with increasing temperatures, this can lead to shifts in the time window available for successful breeding of birds associated with the riverine habitat. Here, we investigated specifically how the environmental conditions at the territory level influence timing of breeding in a passerine bird with an aquatic lifestyle, the white-throated dipper Cinclus cinclus. We relate daily river discharge and other important hydrological parameters, to a long-term dataset of breeding phenology (1978–2015) in a natural river system. Results Dippers bred earlier when winter river discharge and groundwater levels in the weeks prior to breeding were high, and when there was little snow in the catchment area. Breeding was also earlier at lower altitudes, although the effect dramatically declined over the period. This suggests that territories at higher altitudes had more open water in winter later in the study period, which permitted early breeding also here. Unexpectedly, the largest effect inducing earlier breeding time was territory river discharge during the winter months and not immediately prior to breeding. The territory river discharge also increased during the study period. Conclusions The observed earlier breeding can thus be interpreted as a response to climate change. Measuring environmental variation at the scale of the territory thus provides detailed information about the interactions between organisms and the abiotic environment.

scholarly journals Environmental factors influence the detection probability in acoustic telemetry in a marine environment: results from a new setup

Hydrobiologia ◽  
2018 ◽  
Vol 845 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Jan Reubens ◽  
Pieterjan Verhelst ◽  
Inge van der Knaap ◽  
Klaas Deneudt ◽  
Tom Moens ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Marine Environment ◽  
Detection Probability ◽  
Acoustic Telemetry

scholarly journals Aerosol-cloud-turbulence interactions in well-coupled Arctic boundary layers over open water

2021 ◽  
Author(s):  
Jan Chylik ◽  
Dmitry Chechin ◽  
Regis Dupuy ◽  
Birte S. Kulla ◽  
Christof Lüpkes ◽  
...  
Keyword(s):  
Large Scale ◽  
Convective Cloud ◽  
Open Water ◽  
Convective Transport ◽  
Cloud Layer ◽  
Mixed Phase ◽  
State Variables ◽  
Strongly Coupled ◽  
Main Research ◽  
Weather Model

Abstract. Late springtime Arctic mixed-phase convective clouds over open water in the Fram Strait as observed during the recent ACLOUD field campaign are simulated at turbulence-resolving resolutions. The main research objective is to gain more insight into the coupling of these cloud layers to the surface, and into the role played by interactions between aerosol, hydrometeors and turbulence in this process. A composite case is constructed based on data collected by two research aircraft on 18 June 2017. The boundary conditions and large-scale forcings are based on weather model analyses, yielding a simulation that freely equilibrates towards the observed thermodynamic state. The results are evaluated against a variety of independent aircraft measurements. The observed cloud macro- and microphysical structure is well reproduced, consisting of a stratiform cloud layer in mixed-phase fed by surface-driven convective transport in predominantly liquid phase. Comparison to noseboom turbulence measurements suggests that the simulated cloud-surface coupling is realistic. A joint-pdf analysis of relevant state variables is conducted, suggesting that locations where the mixed-phase cloud layer is strongly coupled to the surface by convective updrafts act as hot-spots for invigorated interactions between turbulence, clouds and aerosol. A mixing-line analysis reveals that the turbulent mixing is similar to warm convective cloud regimes, but is accompanied by hydrometeor transitions that are unique for mixed-phase cloud systems. Distinct fingerprints in the joint-pdf diagrams also explain i) the typical ring-like shape of ice mass in the outflow cloud deck, ii) its slightly elevated buoyancy, and iii) an associated local minimum in CCN.

scholarly journals Impact of extreme drought and incentive programs on flooded agriculture and wetlands in California’s Central Valley

2018 ◽  
Author(s):  
Matthew E Reiter ◽  
Nathan Elliott ◽  
Dennis Jongsomjit ◽  
Gregory H Golet ◽  
Mark D Reynolds
Keyword(s):  
Surface Water ◽  
Large Fraction ◽  
Central Valley ◽  
Open Water ◽  
Extreme Drought ◽  
Freshwater Wetland ◽  
Post Harvest ◽  
Incentive Programs ◽  
Managed Wetlands ◽  
The Impact

Between 2013 and 2015 a large part of the western United States, including the Central Valley of California, sustained an extreme drought. The Central Valley is recognized as a region of hemispheric importance for waterbirds which use flooded agriculture and wetlands as habitat. Thus, the impact of drought on the distribution of surface water needed to be assessed to understand the effects on waterbird habitat availability. We used satellites to quantify the impact the recent extreme drought on the timing and extent of available waterbird habitat during the non-breeding season (July – May) by examining flooding in agriculture (rice, corn, and other crops) and managed wetlands across the Central Valley. We assessed the influence of habitat incentive programs, particularly The Nature Conservancy’s BirdReturns and the Natural Resources Conservation Service’s Waterbird Habitat Enhancement Program (WHEP), at offsetting waterbird habitat loss related to drought. Overall, we found significant declines in open water in post-harvest agriculture (20 – 80% declines) and in managed wetlands (47 – 59% declines) during the 2013 – 2015 drought compared to non-drought years 2000 – 2011. Crops associated with the San Joaquin Valley, specifically corn, as well as wetlands in that part of the Central Valley exhibited larger reductions in open water than rice and wetlands in the Sacramento Valley. However, seasonal wetlands on protected lands had a marginally significant (P<0.10) higher amount of open water in the drought years than those on non-protected lands. A large fraction of the daily open water in rice during certain times of the year, particularly in the fall for BirdReturns (64%) and the winter for WHEP (100%), may have been provided through incentive programs underscoring the contribution of these programs. However, further assessment is needed to know how much the incentive programs directly offset the impact of drought in post-harvest rice or simply supplemented funding for activities that might have been done regardless. Our, first of its kind, landscape analysis documents the significant impacts of the drought on freshwater wetland habitats in the Central Valley and highlights the value of using satellite data to track surface water and waterbird habitats. More research is needed to understand subsequent impacts on the freshwater dependent species that rely on these systems and how incentive programs can most strategically support vulnerable species during future drought.

scholarly journals The Treatment of Shortwave Radiation and Open Water in Large-Scale Models of Sea-Ice Decay

1990 ◽  
Vol 14 ◽  
pp. 242-246
Author(s):  
Donald K. Perovich ◽  
Gary A. Maykut
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
Open Water ◽  
Shortwave Radiation ◽  
Areal Extent ◽  
Time Step ◽  
Climate Simulations ◽  
Scale Models ◽  
Ice Concentration ◽  
Ice Pack

Sea ice covering the polar oceans is only a thin veneer whose areal extent can undergo large and rapid variations in response to relatively small changes in thermal forcing. Positive feedback between variations in ice extent and global albedo has the potential to amplify small changes in climate. Particularly difficult to model is the summer decay and retreat of the ice pack which is strongly influenced by shortwave radiation entering the upper ocean through leads (Iw). Most models assume that all of this energy is expended in lateral melting at floe edges. In reality, only a portion of Iw contributes directly to lateral melting, with the remainder going to bottom ablation and warming of the water. This partitioning of Iw affects not only the magnitude, but also the character of the predicted ice decay, reducing the change in ice concentration and enhancing the thinning of the ice and the storage of heat in the water. In this paper we present an analytical model which includes many of these processes and is stable regardless of time step, making it suitable for use in climate simulations.

scholarly journals E-DATA: A Comprehensive Field Campaign to Investigate Evaporation Enhanced by Advection in the Hyper-Arid Altiplano

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 745 ◽  
Author(s):  
Francisco Suárez ◽  
Felipe Lobos ◽  
Alberto de la Fuente ◽  
Jordi Vilà-Guerau de Arellano ◽  
Ana Prieto ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Open Water ◽  
Water Evaporation ◽  
Distributed Temperature Sensing ◽  
Field Campaign ◽  
Spatial And Temporal Scales ◽  
Airborne Measurements ◽  
Dry Air ◽  
Evaporation Dynamics

In the endorheic basins of the Altiplano, water is crucial for sustaining unique ecological habitats. Here, the wetlands act as highly localized evaporative environments, and little is known about the processes that control evaporation. Understanding evaporation in the Altiplano is challenging because these environments are immersed in a complex topography surrounded by desert and are affected by atmospheric circulations at various spatial scales. Also, these environments may be subject to evaporation enhancement events as the result of dry air advection. To better characterize evaporation processes in the Altiplano, the novel Evaporation caused by Dry Air Transport over the Atacama Desert (E-DATA) field campaign was designed and tested at the Salar del Huasco, Chile. The E-DATA combines surface and airborne measurements to understand the evaporation dynamics over heterogeneous surfaces, with the main emphasis on the open water evaporation. The weather and research forecasting model was used for planning the instruments installation strategy to understand how large-scale air flow affects evaporation. Instrumentation deployed included: meteorological stations, eddy covariance systems, scintillometers, radiosondes and an unmanned aerial vehicle, and fiber-optic distributed temperature sensing. Additional water quality and CO2 fluxes measurements were carried out to identify the link between meteorological conditions and the biochemical dynamics of Salar del Huasco. Our first results show that, in the study site, evaporation is driven by processes occurring at multiple spatial and temporal scales and that, even in the case of available water and energy, evaporation is triggered by mechanical turbulence induced by wind.

scholarly journals Massive MIMO-Based Distributed Signal Detection in Multi-Antenna Wireless Sensor Networks

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2005
Author(s):  
Guofeng Wei ◽  
Bangning Zhang ◽  
Guoru Ding ◽  
Bing Zhao ◽  
Yimin Wei ◽  
...  
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Sensor Network ◽  
Detection Probability ◽  
Massive Mimo ◽  
Large Scale ◽  
Multiple Input Multiple Output ◽  
Wireless Sensor ◽  
Channel State ◽  
Single Antenna

For massive multiple-input multiple-output (MIMO) distributed wireless sensor networks, this paper investigates the role of multi-antenna sensors in improving network perception performance. First, we construct a distributed multi-antenna sensor network based on massive MIMO. By using the anti-fading characteristics of multi-antennas, it is better to achieve accurate detection than the single-antenna sensor network. Based on this, we derive a closed-loop expression for the detection probability of the best detector. Then, we consider the case that the sensor power resources are limited, and thus we want to use finite power to achieve higher detection probability. For this reason, the power was optimized by the alternating direction method of multipliers (ADMM). Moreover, we also prove that only statistical channel state is needed in large-scale antenna scenarios, which avoid the huge overhead of channel state information. Finally, according to the simulation results, the multi-antenna sensor network has better detection performance than the single-antenna sensor network which demonstrates the improved performance of the proposed schemes and also validates the theoretical findings.

Investigation of a High Precision Hydrostatic Actuation System: How Nonlinearities Affect Its Performance

2007 ◽  
Author(s):  
Wei Li ◽  
Richard Burton ◽  
Saeid Habibi
Keyword(s):  
Large Scale ◽  
Linear Models ◽  
Hydraulic Actuator ◽  
Complete Understanding ◽  
Positional Accuracy ◽  
Scale Modeling ◽  
Actuation System ◽  
Order Change ◽  
Physical Limitations ◽  
Large Scale Modeling

A prototype Electro-Hydraulic Actuator (EHA) system has demonstrated a positional accuracy in the order of 100 nanometer. Linearized models of the EHA have been formulated and have shown reasonable correlation to the performance of the physical EHA. However, these models predict zero steady state error (an impossible situation given the physical limitations of seals, friction etc.). Further, the prototype EHA indicates that the cut-off frequency decreases as the amplitude of the input signal decreases. This is not predicted by the linear models. In this paper the Bond-graph large scale modeling technique was used as the basis to formulate the describing equations of the EHA. The model was made increasingly more complex by introducing observable nonlinearities into the model. It was found that the introduction of nonlinear friction did show results whose trends were consistent with those observed experimentally. Assumed nonlinearities in the bulk modulus could not be substantiated. In addition, some of the observed experimental trends could not be predicted (such as order change) and pose additional challenges to be solved before a complete understanding of the true physics of the EHA can be realized.

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