Fish on the move: connectivity of an estuary-dependent fishery species evaluated using a large-scale acoustic telemetry array

2018 ◽  
Vol 75 (11) ◽  
pp. 2038-2052 ◽  
Author(s):  
Taryn S. Murray ◽  
Paul D. Cowley ◽  
Rhett H. Bennett ◽  
Amber-Robyn Childs
Keyword(s):  
Environmental Variables ◽  
Acoustic Telemetry ◽  
Large Scale ◽  
Time Of Day ◽  
Sea Temperature ◽  
Marine Habitats ◽  
Receiver Array ◽  
Acoustic Receiver ◽  
Rhythmic Cycles ◽  
Fishery Species

Connectivity — movements of animals between and among numerous habitats — and the factors (rhythmic cycles and environmental variables) influencing connectivity of juvenile Lichia amia (Teleostei: Carangidae) were assessed in complementary acoustic telemetry studies in two geographically separated estuaries (620 km apart) in South Africa. The studies were conducted within a nationwide array of acoustic receivers moored in estuaries and coastal waters. Tagged fish in both the Kowie (n = 21) and Goukou (n = 17) estuaries displayed high levels of multiple habitat connectivity, with 81% and 76% visiting nearby marine and estuarine environments, respectively. The presence of tagged L. amia within the tagging estuaries was significantly influenced by river and sea temperature (Kowie) and river inflow and moon phase (Goukou). Tidal phase, time of day, and season were found to significantly influence marine excursions undertaken by Kowie- and Goukou-tagged fish. Our study provides an assessment of connectivity among multiple estuarine, port, and marine habitats, relating those movements to rhythmic cycles and environmental variables, and highlights the benefits of tracking animals using an extensive acoustic receiver array that spans multiple habitats.

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 The influence of dynamic environmental interactions on detection efficiency of acoustic transmitters in a large, deep, freshwater lake

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Natalie V. Klinard ◽  
Edmund A. Halfyard ◽  
Jordan K. Matley ◽  
Aaron T. Fisk ◽  
Timothy B. Johnson
Keyword(s):  
Study Design ◽  
Environmental Conditions ◽  
Power Output ◽  
Environmental Variables ◽  
Acoustic Telemetry ◽  
Detection Efficiency ◽  
Data Interpretation ◽  
Heterogeneous Environments ◽  
Depth Range ◽  
Dynamic Relationship

Abstract Background Acoustic telemetry is an increasingly common method used to address ecological questions about the movement, behaviour, and survival of freshwater and marine organisms. The variable performance of acoustic telemetry equipment and ability of receivers to detect signals from transmitters have been well studied in marine and coral reef environments to inform study design and improve data interpretation. Despite the growing use of acoustic telemetry in large, deep, freshwater systems, detection efficiency and range, particularly in relation to environmental variation, are poorly understood. We used an array of 90 69-kHz acoustic receivers and 8 sentinel range transmitters of varying power output deployed at different depths and locations approximately 100–9500 m apart for 215 days to evaluate how the detection efficiency of acoustic receivers varied spatially and temporally in relation to environmental conditions. Results The maximum distance that tags were detected ranged from 5.9 to 9.3 km. Shallow tags consistently had lower detection efficiency than deep tags of the same power output and detection efficiency declined through the winter months (December–February) of the study. In addition to the distance between tag and receiver, thermocline strength, surface water velocity, ice thickness, water temperature, depth range between tag and receiver, and number of fish detections contributed to explaining variation in detection efficiency throughout the study period. Furthermore, the most significant models incorporated interactions between several environmental variables and tag–receiver distance, demonstrating the complex temporal and spatial relationships that exist in heterogeneous environments. Conclusions Relying on individual environmental variables in isolation to interpret receiver performance, and thus animal behaviour, may be erroneous when detection efficiency varies across distances, depths, or tag types. As acoustic telemetry becomes more widely used to study ecology and inform management, it is crucial to understand its limitations in heterogeneous environments, such as freshwater lakes, to improve the quality and interpretation of data. We recommend that in situ range testing and retrospective analysis of detection efficiency be incorporated into study design for telemetry projects. Furthermore, we caution against oversimplifying the dynamic relationship between detection efficiency and environmental conditions for the sake of producing a correction that can be applied directly to detection data of tagged animals when the intended correction may not be justified.

scholarly journals Whole-genome sequence data suggests environmental adaptation of Ethiopian sheep populations

2021 ◽  
Author(s):  
Pamela Wiener ◽  
Christelle Robert ◽  
Abulgasim Ahbara ◽  
Mazdak Salavati ◽  
Ayele Abebe ◽  
...  
Keyword(s):  
High Altitude ◽  
Environmental Variables ◽  
Large Scale ◽  
Sequence Data ◽  
Strong Association ◽  
Environmental Adaptation ◽  
Whole Genome Sequence ◽  
Single Nucleotide Variants ◽  
High Altitude Adaptation ◽  
Altitude Adaptation

Abstract Great progress has been made over recent years in the identification of selection signatures in the genomes of livestock species. This work has primarily been carried out in commercial breeds for which the dominant selection pressures, are associated with artificial selection. As agriculture and food security are likely to be strongly affected by climate change, a better understanding of environment-imposed selection on agricultural species is warranted. Ethiopia is an ideal setting to investigate environmental adaptation in livestock due to its wide variation in geo-climatic characteristics and the extensive genetic and phenotypic variation of its livestock. Here, we identified over three million single nucleotide variants across 12 Ethiopian sheep populations and applied landscape genomics approaches to investigate the association between these variants and environmental variables. Our results suggest that environmental adaptation for precipitation-related variables is stronger than that related to altitude or temperature, consistent with large-scale meta-analyses of selection pressure across species. The set of genes showing association with environmental variables was enriched for genes highly expressed in human blood and nerve tissues. There was also evidence of enrichment for genes associated with high-altitude adaptation although no strong association was identified with hypoxia-inducible-factor (HIF) genes. One of the strongest altitude-related signals was for a collagen gene, consistent with previous studies of high-altitude adaptation. Several altitude-associated genes also showed evidence of adaptation with temperature, suggesting a relationship between responses to these environmental factors. These results provide a foundation to investigate further the effects of climatic variables on small ruminant populations.

scholarly journals Carbon dioxide fluxes increase from day to night across European streams

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Katrin Attermeyer ◽  
Joan Pere Casas-Ruiz ◽  
Thomas Fuss ◽  
Ada Pastor ◽  
Sophie Cauvy-Fraunié ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Carbon Dioxide Flux ◽  
Time Of Day ◽  
Night Time ◽  
Carbon Dioxide Fluxes ◽  
Large Scale Assessment ◽  
Air Interface ◽  
Flux Variability

AbstractGlobally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

Acoustic tracking: issues affecting design, analysis and interpretation of data from movement studies

2012 ◽  
Vol 63 (4) ◽  
pp. 312 ◽  
Author(s):  
Jason Richard How ◽  
Simon de Lestang
Keyword(s):  
Acoustic Telemetry ◽  
Full Moon ◽  
Water Movement ◽  
Lunar Cycle ◽  
Time Of Day ◽  
Detection Distance ◽  
Detection Rates ◽  
Detection Frequency ◽  
Analytical Work ◽  
Power Outputs

Acoustic telemetry systems are an increasingly common way to examine the movement and behaviour of marine organisms. However, there has been little published on the methodological and analytical work associated with this technology. We tested transmitters of differing power outputs simultaneously in several trials, some lasting ~50 days, to examine the effects of power output and environmental factors (water movement, temperature, lunar cycle and time of day). There were considerable and volatile changes in detections throughout all trials. Increased water movement and temperature significantly reduced detection rates, whereas daytime and full-moon periods had significantly higher detection rates. All nine transmitters (from seven transmitter types tested) showed a sigmoidal trend between detection frequency and distance. Higher-powered transmitters had a prolonged detection distance with near-maximal detections, whereas lower-powered transmitters showed an almost immediate decline. Variation of detection frequency, transmitter type and the modelled relationship between distance and detection frequency were incorporated into a positioning trial which resulted in markedly improved position estimates over previous techniques.

After-Hours Telephone Coverage: The Application of an Area-Wide Telephone Triage and Advice System for Pediatric Practices

PEDIATRICS ◽  
1993 ◽  
Vol 92 (5) ◽  
pp. 670-679 ◽  
Author(s):  
Steven R. Poole ◽  
Barton D. Schmitt ◽  
Thea Carruth ◽  
Ann Peterson-Smith ◽  
Minnie Slusarski
Keyword(s):  
Home Care ◽  
Patient Care ◽  
Large Scale ◽  
Time Of Day ◽  
Physician Satisfaction ◽  
Telephone Triage ◽  
Total Cost ◽  
Phone Calls ◽  
After Hours ◽  
Telephone Calls

Background. After-hours telephone calls are a stressful and frustrating aspect of pediatric practice. At the request of private practice pediatricians in Denver, a metropolitan area-wide system was created to manage after-hours pediatric telephone calls and after-hours patient care. This system, the After-Hours Program (AHP), uses specially trained pediatric nurses with standardized protocols to provide after-hours telephone triage and advice for the patients of 92 Denver pediatricians, representing 56 practices. Objectives. This report describes the AHP, presents data from 4 years' experience with the program, and describes results of our evaluation of the following aspects of the program: subscribing physician satisfaction, parent satisfaction, the accuracy and appropriateness of telephone triage, and program costs. Methods. After-Hours Program records (including quality assurance data) for all 4 years of operation were retrospectively reviewed, tabulated, and analyzed. The results of two subscribing physician surveys and one parent caller satisfaction survey are presented. A retrospective review of after-hours patient care encounter forms assessed the necessity for after-hours visits triaged by the AHP. An analysis of the total cost of this program to 10 randomly selected subscribing physicians was conducted using current AHP data and a survey of the 10 physicians. Results. In 4 years, 107 938 calls have been successfully managed without an adverse clinical outcome. Minor errors in using protocols occurred in one call out of 1450 after-hours calls. After-hours phone calls necessitated an after-hours patient visit 20% of the time and generated one after-hours hospital admission out of every 88 calls. Just over half of the patients were managed with home care advice only, and 28% were given home care advice after-hours and seen the next day in the primary physician's office. Of all patients directed by the telephone triage nurses to be seen after hours, 78% were determined to have a condition necessitating after-hours care. Data are presented regarding call volumes by time of day, day of week, patient age, and patient's initial complaint. The 6 most common complaints accounted for more than one half of the calls, and 38 complaints accounted for more than 95% of all after-hours calls. Utilization by subscribing physicians is described. Satisfaction among subscribing pediatricians was 100%, and among parents was 96% to 99% on a variety of issues. The total cost to participating Denver pediatricians (which includes revenues "given up" as a result of not seeing patients after hours) ranged from 1% to 12% of their annual net income, depending on a variety of factors. Conclusions. Large-scale after-hours telephone coverage systems can be effective and well-received by patients, parents, and primary physicians. Data presented in this report can assist in planning the training of personnel who provide after-hours telephone advice and triage. Controversies associated with this type of program are discussed. Suggestions are made regarding the direction of future programs and research.

scholarly journals Explaining the ocean's richest biodiversity hotspot and global patterns of fish diversity

2018 ◽  
Vol 285 (1888) ◽  
pp. 20181314 ◽  
Author(s):  
Elizabeth Christina Miller ◽  
Kenji T. Hayashi ◽  
Dongyuan Song ◽  
John J. Wiens
Keyword(s):  
Large Scale ◽  
Fish Diversity ◽  
Relative Importance ◽  
Diversification Rates ◽  
Marine Habitats ◽  
History Of ◽  
Richness Patterns ◽  
Colonization Time ◽  
Almost All

For most marine organisms, species richness peaks in the Central Indo-Pacific region and declines longitudinally, a striking pattern that remains poorly understood. Here, we used phylogenetic approaches to address the causes of richness patterns among global marine regions, comparing the relative importance of colonization time, number of colonization events, and diversification rates (speciation minus extinction). We estimated regional richness using distributional data for almost all percomorph fishes (17 435 species total, including approximately 72% of all marine fishes and approximately 33% of all freshwater fishes). The high diversity of the Central Indo-Pacific was explained by its colonization by many lineages 5.3–34 million years ago. These relatively old colonizations allowed more time for richness to build up through in situ diversification compared to other warm-marine regions. Surprisingly, diversification rates were decoupled from marine richness patterns, with clades in low-richness cold-marine habitats having the highest rates. Unlike marine richness, freshwater diversity was largely derived from a few ancient colonizations, coupled with high diversification rates. Our results are congruent with the geological history of the marine tropics, and thus may apply to many other organisms. Beyond marine biogeography, we add to the growing number of cases where colonization and time-for-speciation explain large-scale richness patterns instead of diversification rates.

scholarly journals Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fernando Martínez-Freiría ◽  
Ken S. Toyama ◽  
Inês Freitas ◽  
Antigoni Kaliontzopoulou
Keyword(s):  
Solar Radiation ◽  
Environmental Variables ◽  
Large Scale ◽  
Monophyletic Group ◽  
Comparative Approach ◽  
Cold Environments ◽  
Zigzag Pattern ◽  
High Predation ◽  
Dorsal Pattern ◽  
Thermal Melanism

Abstract Colouration may endorse thermoregulatory and antipredatory functions in snakes. The thermal melanism hypothesis predicts that dark-coloured individuals are ecologically favoured in cool climates. However, the loss of aposematic and cryptic colourations may imply high predation for melanistic snakes. Here, we used the monophyletic group of Eurasian vipers (subfamily Viperinae) to test whether an increase in the extent of dark area inside the characteristic zigzag dorsal pattern is associated to colder environments. We measured two colouration traits in zigzag-patterned individuals (number of dorsal marks and weighted pigmentation index) and used a phylogenetic comparative approach to explore macroevolutionary patterns of dorsal pigmentation and test whether its extent is associated to ecogeographic characteristics of lineages’ ranges. Phylogenetically-naïve and phylogenetically-informed analyses yielded a significant association between the degree of pigmentation of the zigzag pattern and environmental variables such as solar radiation, elevation and latitude. The degree of pigmentation of the zigzag pattern is highlighted as an adaptive trait that matches range attributes mirroring cold environments irrespective of the phylogeny. These results constitute the first large-scale evidence supporting the thermal melanism hypothesis in snakes, opening new avenues of inquiry for the mechanisms that shape the evolution of colour phenotypes.

scholarly journals Application of Sentinel-2 Multispectral Data for Habitat Mapping of Pacific Islands: Palau Republic (Micronesia, Pacific Ocean)

2019 ◽  
Vol 7 (9) ◽  
pp. 316 ◽  
Author(s):  
Francesco Immordino ◽  
Mattia Barsanti ◽  
Elena Candigliota ◽  
Silvia Cocito ◽  
Ivana Delbono ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Pacific Ocean ◽  
Large Scale ◽  
Pacific Islands ◽  
Satellite Image ◽  
Unsupervised Classification ◽  
Habitat Mapping ◽  
Ancillary Data ◽  
Marine Habitats ◽  
Sentinel 2

Sustainable and ecosystem-based marine spatial planning is a priority of Pacific Island countries basing their economy on marine resources. The urgency of management coral reef systems and associated coastal environments, threatened by the effects of climate change, require a detailed habitat mapping of the present status and a future monitoring of changes over time. Here, we present a remote sensing study using free available Sentinel-2 imagery for mapping at large scale the most sensible and high value habitats (corals, seagrasses, mangroves) of Palau Republic (Micronesia, Pacific Ocean), carried out without any sea truth validation. Remote sensing ‘supervised’ and ‘unsupervised’ classification methods applied to 2017 Sentinel-2 imagery with 10 m resolution together with comparisons with free ancillary data on web platform and available scientific literature were used to map mangrove, coral, and seagrass communities in the Palau Archipelago. This paper addresses the challenge of multispectral benthic mapping estimation using commercial software for preprocessing steps (ERDAS ATCOR) and for benthic classification (ENVI) on the base of satellite image analysis. The accuracy of the methods was tested comparing results with reference NOAA (National Oceanic and Atmospheric Administration, Silver Spring, MD, USA) habitat maps achieved through Ikonos and Quickbird imagery interpretation and sea-truth validations. Results showed how the proposed approach allowed an overall good classification of marine habitats, namely a good concordance of mangroves cover around Palau Archipelago with previous literature and a good identification of coastal habitats in two sites (barrier reef and coastal reef) with an accuracy of 39.8–56.8%, suitable for survey and monitoring of most sensible habitats in tropical remote islands.

Sign in / Sign up

Export Citation Format

Share Document