Inform Management Decisions Research Articles

The application of catch–effort models to estimate the efficacy of aerial shooting operations on sambar deer (Cervus unicolor)

Context Aerial shooting from a helicopter targeting introduced sambar deer (Cervus unicolor) is a key activity being undertaken on public land in the North East and East Gippsland regions of Victoria. However, there is currently little published information on the efficacy of aerial shooting for reducing sambar deer populations in Australia. Aims The aims of this study were to analyse the operational data collected during an aerial shooting program in eastern Victoria, to assess the efficacy of aerial shooting at reducing sambar deer density and to inform management decisions on the required intensity of aerial shooting to achieve target densities. Methods Operational data (locations of all shot animals as well as aerial search effort) were analysed from 10 sites using a Bayesian generalised catch–effort model, which allowed for population changes between five periods of intensive control. The model allowed estimates of initial and residual abundance for each site to be made from the catch–effort data, which were used to estimate the efficacy of aerial shooting. Estimates of the detection rate of deer, which were allowed to vary with removal occasion and site, were then used to estimate the amount of aerial search effort required to reduce population densities by various proportional amounts. Key results Aerial shooting resulted in population reductions of 50–70% of sambar deer at four sites where aerial search intensities per unit area were highest. However, results at the remaining sites suggest that sambar deer densities have either remained static or increased over the five periods of aerial control. Recruitment of sambar deer between control periods, which was strongly influenced by study site elevation and season, was largely responsible for eroding reductions achieved by aerial shooting. Conclusions Catch–effort models applied to operational data collected during aerial shooting programs can be used to estimate control efficacy without the need for additional monitoring. Our analysis suggests that sufficiently high search intensities, around 1.4 km of search effort per km2 of habitat in each of five removal occasions, would need to be applied to achieve at least a 50% reduction in sambar deer densities.

Monitoring threatened species with environmental DNA and open ecological data: Local distribution and habitat preferences of scalloped hammerhead sharks (Sphyrna lewini)

Evidence-based environmental management is urgently required to enable progress towards global conservation commitments. To fill large-scale biodiversity knowledge gaps, governments, organisations and communities must adopt innovative ecological monitoring techniques. The emergence of environmental DNA (eDNA) survey methods, as well as the increased availability of in situ ocean observation and satellite remote sensing data, offers opportunities to overcome significant logistic and financial challenges previously associated with traditional biodiversity monitoring. Here, a 1.5 year-long eDNA survey reveals the spatial and temporal presence of ‘critically endangered’ scalloped hammerhead sharks (Sphyrna lewini) in Apra Harbor, Guam. The survey confirms the presence of S. lewini in the region, and shows eDNA detections are most frequent at the beginning of the dry season, in January. Combined analysis of eDNA results with open (freely available) ecological data identifies that S. lewini presence is associated with increases in water velocity, turbidity and wind direction, as well as decreases in temperature and wind speed. Additionally, the data indicate S. lewini are most frequent at sampling sites characterised by high turbidity, shallow depths, and large distances from the harbor entrance. Information on local distribution and habitat preferences generated here is fundamental to the establishment of management protocols that aim to minimise negative anthropogenic impacts on S. lewini in Apra Harbor. The work provides an example of contemporary marine monitoring for the efficient generation of biodiversity data; an approach that will enable informed management decisions and help to reduce the risk and rate of species extinctions throughout the next decade.

Increasing Sodium Variability in the First 96 Hours after Birth is Associated with Adverse In-Hospital Outcomes of Preterm Newborns

BackgroundNeonatal intraventricular hemorrhage prevention bundles for preterm infants commonly defer daily weighing for the first 72 h, with reweighing occurring on day 4. Clinicians rely on maintaining stable sodium values as a proxy of fluid status to inform fluid management decisions over the first 96 h after birth. Yet, there exists a paucity of research evaluating whether serum sodium or osmolality are appropriate proxies for weight loss and whether increasing variability in sodium or osmolality during this early transitional period is associated with adverse in-hospital outcomes. ObjectivesTo evaluate whether serum sodium or osmolality change in the first 96 h after birth was associated with percent weight change from birth weight, and to assess potential associations between serum sodium and osmolality variability with in-hospital outcomes. MethodsThis retrospective, cross-sectional study included neonates born at ≤30 gestational weeks or ≤1250 g. We evaluated associations between serum sodium coefficient of variation (CoV), osmolality CoV, and maximal weight loss percentage in the first 96 h after birth with in-hospital neonatal outcomes. ResultsAmong 205 infants, serum sodium and osmolality were poorly correlated with percent weight change in individual 24-h increments (R2 = 0.01–0.14). For every 1% increase in sodium CoV, there was an associated 2-fold increased odds of surgical necrotizing enterocolitis and 2-fold increased odds of in-hospital mortality (odds ratio, 2.07; 95% CI: 1.02, 4.54; odds ratio, 1.95; 95% CI: 1.10, 3.64, respectively). Sodium CoV was more strongly associated with outcomes than absolute sodium maximal change. ConclusionsIn the first 96 h, serum sodium and osmolality are poor proxies for assessing percent weight change. Increasing variability of serum sodium is associated with later development of surgical necrotizing enterocolitis and all-cause in-hospital mortality. Prospective research is needed to evaluate whether reducing sodium variability in the first 96 h after birth, as assessed by CoV, improves newborn health outcomes.

Bridging conservation across the ex situ-in situ spectrum: Insights into the reproductive ecology of the threatened narrow-headed gartersnake (Thamnophis rufipunctatus).

Zoo-based (ex situ) conservation breeding programs provide invaluable opportunities to uncover enigmatic behaviors and traits of focal species under managed care, which can support research and conservation management efforts. A suite of factors and a limited range have yielded population declines in the threatened narrow-headed gartersnake (Thamnophis rufipunctatus). Better understanding its cryptic ecology and life history (e.g., reproductive ecology) offers conservation benefits. We analyzed data on courtship behavior, parity and litter size, offspring size, and neonatal growth from an ex situ T. rufipunctatus population at the Phoenix Zoo from 2009 to 2018. Courtship behavior and parturition phenology are likely linked with the North American monsoon season, yet the courtship window may be wider than realized. We document the first instances of interannual iteroparity and multigenerational rearing of successful breeders at the ex situ level. Litter sizes varied but were relative to maternal body mass, suggesting that fecundity may be driven by intrinsic condition (e.g., age and size) of breeding females. Mean offspring body masses were equivalent between sexes, and neonate growth trends were quadratic during their first 9 months. Sexual dimorphism became apparent around 4-5 months age. Much of these data are novel for T. rufipunctatus and provide insight into their reproductive ecology. Phenology of reproductive ecology and body size metrics can guide field surveillance, age estimations, and population ecology monitoring, as well as inform ex situ adaptive management practices. Strategies spanning the ex situ-in situ spectrum are applicable to other imperiled taxa to better inform conservation management decisions.

Effects of filtration timing and pore size on measured nutrient concentrations in environmental water samples

AbstractNutrient monitoring is important for informing management decisions to mitigate eutrophication in aquatic systems. Many nutrient monitoring programs use filter pore sizes that allow microorganisms to pass into samples and/or wait extended times between sample collection and filtration/preservation, allowing microbial processes to alter nutrient concentrations. Here, 34 sites were sampled to determine how filter pore size and filtration timing affected measured ammonium (NH4+) and orthophosphate (ortho‐P) concentrations. Three filter pore sizes (0.22, 0.45, and 0.70 μm) were used to filter water immediately upon collection and after 5 and 22 h in a bottle. NH4+ and ortho‐P concentrations varied relative to “baseline” measurements (i.e., 0.22 μm, field‐filtered samples), both over time and with different filter pore sizes, and showed no predictable direction of change based on ambient nutrient concentration or trophic status. As expected, larger relative changes occurred with lower ambient concentrations; however, for the entire dataset, samples with > 1 μmol L−1 ortho‐P and > 3 μmol L−1 NH4+ were lower by 11 and 33%, respectively, which would result in reported nutrient concentrations that were not representative of in situ conditions. Whole‐water samples filtered after 22 h varied up to 3070% for NH4+ and 480% for ortho‐P from baseline concentrations. Filtering water samples with a 0.22 filter (or 0.45 μm, at worst), immediately upon collection, should be adopted as standard practice to ensure that reported nutrient concentrations represent the most accurate measurement possible. Inconsistent and/or insufficient sampling and sample handling procedures can lead to poorly calibrated models and misinformed management and legislative decisions.

Carbon uptake by Douglas-fir is more sensitive to increased temperature and vapor pressure deficit than reduced rainfall in the western Cascade Mountains, Oregon, USA

Understanding how trees respond to drought is critical to understanding forest sensitivity to global climate change, which can help inform forest policy and management decisions. However, mechanisms governing carbon fixation and water fluxes in response to increased temperatures and water limitation in regions with Mediterranean climates, with wet winters and dry summers, remain only partially understood. We tested the effect of increased vapor pressure deficit (VPD) and decreased rainfall on water and carbon fluxes of Douglas-fir (Pseudotsuga menziesii) trees using the Soil-Plant-Atmosphere model (SPA). We simulated a 50-year-old Douglas-fir stand on the western slopes of the Cascade Mountains in Oregon, USA. Simulation results showed that increasing the daily maximum VPD by 0.25–2.5 kPa during the summer increased cumulative transpiration by 1–3% and decreased cumulative gross primary production by 3–25%. In contrast, decreasing rainfall by 10–100% during the spring and summer decreased cumulative transpiration by 2–16% and decreased cumulative gross primary production by 0.5–4%. Transpiration was highly sensitive to decreases in rainfall, especially in late spring and early summer but much less sensitive to increases in maximum daily VPD. In contrast, gross primary productivity was much more sensitive to VPD, with summertime increases in VPD having a 5- to 6-fold greater effect on gross primary productivity than did decreasing the rainfall. These results suggested that temperature increases expected from climate change in combination with increases in VPD are likely to reduce forest productivity regardless of soil moisture availability.

Multi-omics eco-surveillance of bacterial community function in legacy contaminated estuary sediments

Complex legacy contamination is a major issue for many estuaries, with toxicity affecting change in bacterial communities, and their provision of associated goods and services. Sequencing surveys of bacterial community composition provide inferred function; however, additional insights may be generated by measurement of realised metabolic phenotypes. We apply multi-omics (genomics, lipidomics, and metabolomics), with traditional sediment quality analyses, to characterise sediment-associated bacterial communities in an estuary subject to legacy metal contamination (Zn, Hg, As, Cd, Cu and Pb). Analyses of bacterial composition and inferred function (genomics) are coupled with measurements of realised bacterial phenotype (metabolomics and lipidomics) at multiple industrialised and reference sites. At sites with the highest sediment metal concentrations (NTB), we also observed increased abundances of hydrocarbon and sulphuric acid metabolites, indicating additional sediment contamination. Bacterial phyla across sampled sites were dominated by Proteobacteria and Desulfobacteria. NTB sites were enriched with metabolically versatile, cooperative and biofilm forming phyla including, Zixibacteria, Spirochaetota, SAR324 clade, Proteobacteria, Latescibacterota, Desulfobacterota, Deferrisomtota and Acidobateriota; with inferred functions characterised by sulphur metabolism, pathways associated with the degradation of complex organic molecules, and fermentation. Reference sites were characterised by enhanced vitamin biosynthesis, cell wall, cofactor and carbohydrate biosynthesis, and CO2 fixation. Measured metabolic phenotypes at NTB sites supported predicted functions, with most consistent change observed to naphthalene and aminobenzoate degradation pathways and carbohydrate metabolism (galactose, amino and nucleotide sugar). Change in NTB metabolite profiles was most highly correlated with sediment Hg concentrations, indicative of toxic exposure and potential for Hg methylation. Lipid profiles generated further insight into potential functional (hydroxy fatty acids) and community level change (ceramide phosphoethanolamines, unsaturated glycerides). Multi-omics outputs provided insights into bacterial community functions, modes of contaminant toxicity and expressed mechanisms of adaptation, necessary to better inform management decisions and predictive models in increasingly human-influenced environments.

Real-World Clinical Outcomes Based on Body Mass Index and Annualized Weight Change in Patients with Idiopathic Pulmonary Fibrosis.

Identification of clinical characteristics associated with prognosis for idiopathic pulmonary fibrosis (IPF) may help to guide management decisions. This analysis utilized data from the Pulmonary Fibrosis Foundation Patient Registry to examine the relationships between clinical outcomes and both body mass index (BMI) at study enrollment (hereafter referred to as baseline BMI) and annualized percent change in body weight in patients with IPF in a real-world setting. The following outcomes over 24months were stratified by baseline BMI and annualized percent change in body weight: all-cause mortality; annualized change in percent predicted forced vital capacity (%FVC), percent predicted diffusing capacity for carbon monoxide, and 6-min walk distance; all-cause and respiratory-related hospitalizations; and acute exacerbations. Overall, 600 patients with IPF were included (baseline BMI: < 25kg/m2, n = 120; 25 to < 30kg/m2, n = 242; ≥ 30kg/m2, n = 238; annualized percent change in body weight: no loss, n = 95; > 0% to < 5% loss, n = 425; ≥ 5% loss, n = 80). Enrollment demographics and characteristics were generally similar across subgroups. There was no association between mortality and BMI. All-cause mortality was lower among patients who experienced no annualized weight loss versus those with ≥ 5% (OR [95%CI] 3.28 [1.15, 10.95]) or > 0 to < 5% weight loss (OR [95%CI] 2.83 [1.14, 8.62]) over 24months. Patients with baseline BMI < 25kg/m2 had a significantly greater estimated annualized decline in %FVC versus patients with baseline BMI ≥ 30kg/m2 (difference [95%CI] 1.47 [0.01, 2.93]). No relationship was observed between %FVC and weight loss. Other clinical outcomes were generally similar across subgroups. Some clinical outcomes may be worse in patients with IPF who have a low BMI (< 25kg/m2) or who experience weight loss over 24months, but the causation for these relationships is unknown. These results may help to inform management decisions for patients with IPF. NCT02758808.

Comparison of Underwater Visual Census (UVC), Underwater Remote Video (RUV), and Handline Used by Fisheries-Independent Programs to Assess Reef Fish

Fisheries managers rely on independent programs to collect data to design and inform management plans and decisions. These programs aim to implement cost-effective, robust monitoring approaches to assess spatiotemporal changes in fish structure and composition using different methods, which could lead to different conclusions. We compared four methods: two types of underwater visual censuses (UVC) (i.e. transect and roving), remote underwater video (RUV), and fishing using handline (HL) to characterize differences, identify potential complementarities, and estimate relative precision among them. All methods were simultaneously performed on 13 sites in Fajardo, eastern Puerto Rico for a total of 26 visits, and nine sites in La Parguera Natural Reserve (LPNR), western Puerto Rico for a total of 43 visits. Multivariate analysis revealed significant dissimilarities between all methods, with higher species diversity, abundances, and biomass observed in UVC and RUV. Patterns of spatial and temporal variation detected with UVC and RUV were significantly correlated among them, but not with HL. Univariate analysis for commercially important species showed that UVC and RUV methods were more precise and time efficient than HL. Complementarity between UVC and RUV was observed with the latter increasing the diversity observed during surveys. This study showed that UVC and RUV were different, however, they can be used complementarily they were significantly correlated. HL should be used when additional information (e.g. sex and age) is needed. A multi-gear approach with increased use in RUVs is recommended depending on the aims of the study to precisely assess a broader diversity.

Future temperature and salinity in Puget Sound, Washington State, under CMIP6 climate change scenarios

AbstractClimate change will reshape estuarine ecosystems through bottom-up and top-down processes, directly affecting species at all trophic levels. To better understand future regional climate change effects on sea surface temperature and salinity, we used empirical downscaling to derive high-resolution time series of future sea surface temperature and salinity in Puget Sound (Washington State, USA). Downscaling was based on scenario outputs of two coarse-resolution Coupled Model Intercomparison Project Phase 6 (CMIP6) general circulation models, GFDL-CM4 and CNRM-CM6-1-HR. We calculated 30-year climatologies for historical and future simulations, calculated the anomalies between historical and future projections, interpolated to a fine-resolution, and applied these downscaled anomalies to a Regional Ocean Modeling System (ROMS) time series, yielding short-term and long-term delta-downscaled forecasts. Downscaled output for Puget Sound showed temperature and salinity variability between scenarios and models, but overall, there was a strong model agreement of future surface warming and freshening in Puget Sound. Spatially, we found regional differences for both temperature and salinity, including higher temperatures in South Puget Sound and lower salinity in Whidbey Basin. Interpreting and applying downscaled CMIP6 projections of temperature and salinity will help assess climate change vulnerability and inform future ecosystem-based management decisions in Puget Sound and other coastal and estuarine systems.

Monitoring mites in orchards: absence or non-detection?

Successful integrated pest management (IPM) programs rely on effective and efficient methods of monitoring pest and beneficial species, including mites. Several methods have been proposed for monitoring mites in Australian orchards, mainly based on examining leaves in situ. During the 2021–2022 growing season we flagged 1–2 pear trees Pyrus communis in each of 192 panels (a panel being trees in a 14 m length of a row) in a pear orchard at Tatura, Victoria, Australia. For each flagged tree we examined mite species occurrence and prevalence using three methods, (1) non-destructive visual examination of 10 leaves per panel using a 10x hand lens (current industry standard), (2) destructive lab-based examination of 4 leaves per flagged tree(s) using a stereo microscope, and (3) destructive lab-based examination of 2 leaves per flagged tree(s) using a stereo microscope. The presence and prevalence of pest mites and the previously released predatory mite Neoseiulus californicus were recorded. Throughout the season we observed various pest mites in the orchard including Tetranychus urticae, Panonychus ulmi, Eriophyes pyri, and Bryobia rubrioculus and the predatory mite N. californicus. However, the number of species detected and the prevalence of detected species on leaves were dependant on sampling method used. Both destructive sampling methods, method (2) and method (3), performed better than the current non-destructive industry standard in terms of species detection and prevalence. The largest differences were seen during the early stages of infestation for mite species other than E. pyri. Early detection of certain mite species is important because it can provide a more accurate estimate of the starting point for Cumulative Leaf Infested Days (CLIDs) calculations, resulting in better informed management decisions. Importantly, detection and prevalence results were similar for methods (2) and (3) despite the greatly reduced sampling effort (time required) for method (3), and overall sampling effort for method (3) was similar to that required for method (1). Therefore, in terms of both accuracy and sampling effort, method (3) outperformed the other two methods we trialled. An obvious limitation of method (3) when compared to current practice is the requirement for a stereo microscope and access to a laboratory or similar facility. Therefore, the method may be more useful for appropriately trained consultants who monitor pests in orchards on behalf of growers. Another limitation with our study was that it was limited to a single growing season in one pear orchard. We therefore recommend further research to validate our observations, and to support recommendations for growers and consultants.

Antibody tests for identification of current and past infection with SARS-CoV-2.

Antibody tests for identification of current and past infection with SARS-CoV-2.

Knowledge reuse for decision aid in additive manufacturing: application on cost quotation support

The expeditiously growing interest in Additive Manufacturing (AM) in various domains and applications leads to different challenges in terms of management and optimisation. These issues are due to the vast amount and type variety of data and knowledge generated across the AM value chain. Therefore, it becomes essential to deliver useful help to support information management and critical decisions along the AM product realisation. This paper proposes a knowledge-based Framework for traceability and decision aid in AM processes. The proposed solution is applied in a critical phase concerning process generation and cost estimation at the beginning of AM project. A software demonstrator is deployed in a real industrial case study: Heat Exchanger for Aircraft.

Using the Motus System to Track Post-Breeding Dispersal of American Kestrels Nesting in Minnesota, USA

ABSTRACT Understanding breeding ground dispersal, migratory timing and routes, and winter distribution of birds that are facing population declines, such as the American Kestrel (Falco sparverius), can provide insight into their life history traits and potentially inform management decisions. We used Lotek NanoTags and CTT LifeTags to track American Kestrels breeding in three locations in Minnesota, USA, across the Motus network. We tagged nine juvenile American Kestrels in July and August 2020 and 24 more kestrels between April and August 2021 (21 adults and three juveniles). We subsequently detected 15 (45%) of the 33 birds tagged. Eleven birds (33%) were detected while still on their breeding grounds; detections on the breeding grounds after tag deployment lasted an average of 64.3 d (SD = 59.7 d) and 19.9 d (SD = 13.2 d) for adults and juveniles, respectively. Two of the three juvenile males left their natal area 44 d after fledging and the third left 68 d after fledging. However, the average date of departure did not differ by age or sex. Twelve of 33 tagged birds (39%) were detected at post-breeding ground locations during flybys (25 events) or stopovers (2 events), and they all followed a relatively consistent migratory pathway from Minnesota through Iowa and Missouri. However, a lack of Motus receiver stations south of Missouri limited our ability to determine wintering areas. The use of the Motus system to determine dispersal and migratory pathways of American Kestrels, while currently limited in the central part of North America by the availability of receiver stations, is a valuable tool in furthering our understanding of American Kestrel life cycles and possibly revealing causes of the species' population decline in North America.

A bayesian network to inform the management of key species in Kosterhavet National Park under contrasting storylines of environmental change

Global climate change and related land use changes are expected to impose unprecedented pressures on coastal biodiversity and ecosystem processes. To sustainably manage coastal ecosystems, it is crucial to predict the consequences of human activities for coastal ecosystems and identify areas for directed abatement measures. Empirical data together with expert knowledge and evidence from the literature were integrated into a Bayesian Belief Network (BBN) for a marine protected area, the Kosterhavet National Park off the Swedish west coast. The variability and interactions of anthropogenic pressures and two key ecosystem components, eelgrass meadows and northern shrimp stock, were tested under four storylines of environmental change. The results show that of the influential drivers of environmental change, only three variables (bottom trawling, leisure boating and aquaculture) are manageable within the national park itself. Scenario analysis suggested that notable gains of both ecosystem components were most likely under a storyline of sustainable development, assuming a radiative forcing of 4.5 W/m2 by 2100 in concert with a preventive cooperation among neighboring countries and a tighter restriction of commercial and recreational uses in the park area. The findings suggest that the sustainable management of eelgrass meadows and northern shrimp stock in Kosterhavet National Park requires both local measures at the scale of the park's water bodies and, to a greater part, also regional measures, e.g., to reduce nutrient influx from adjacent water bodies. In conclusion, this approach can help practitioners to make more informed management decisions and foresee the effects of routes of socio-economic development.

Primed and cued: long-term acoustic telemetry links interannual and seasonal variations in freshwater flows to the spawning migrations of Common Snook in the Florida Everglades

BackgroundSpawning migrations are a widespread phenomenon among fishes, often occurring in response to environmental conditions prompting movement into reproductive habitats (migratory cues). However, for many species, individual fish may choose not to migrate, and research suggests that conditions preceding the spawning season (migratory primers) may influence this decision. Few studies have provided empirical descriptions of these prior conditions, partly due to a lack of long-term data allowing for robust multi-year comparisons. To investigate how primers and cues interact to shape the spawning migrations of coastal fishes, we use acoustic telemetry data from Common Snook (Centropomus undecimalis) in Everglades National Park, Florida, USA. A contingent of Snook migrate between rivers and coastal spawning sites, varying annually in both the proportion of the population that migrates and the timing of migration within the spawning season. However, the specific environmental factors that serve as migratory primers and cues remain unknown.MethodsWe used eight years of acoustic telemetry data (2012–2019) from 173 tagged Common Snook to investigate how primers and cues influence migratory patterns at different temporal scales. We hypothesize that (1) interannual differences in hydrologic conditions preceding the spawning season contribute to the number of individuals migrating each year, and (2) specific environmental cues trigger the timing of migrations during the spawning season. We used GLMMs to model both the annual and seasonal migratory response in relation to flow characteristics (water level, rate of change in water level), other hydrologic/abiotic conditions (temperature, salinity), fish size, and phenological cues independent of riverine conditions (photoperiod, lunar cycle).ResultsWe found that the extent of minimum marsh water level prior to migration and fish size influence the proportion of Snook migrating each year, and that high river water level and daily rates of change serve as primary cues triggering migration timing.ConclusionOur findings illustrate how spawning migrations are shaped by environmental factors acting at different temporal scales and emphasize the importance of long-term movement data in understanding these patterns. Research providing mechanistic descriptions of conditions that promote migration and reproduction can help inform management decisions aimed at conserving ecologically and economically important species.

Detection of brook trout in spatiotemporally separate locations using validated eDNA technology

Brook trout are a species of conservation concern in Southwestern Ontario, Canada, and effective monitoring of their populations is crucial for making informed management decisions. Electrofishing is a traditional, yet invasive, method that allows for fish abundance estimation. Environmental DNA (eDNA) is an emerging molecular tool that presents a non-invasive alternative to electrofishing. This study was a collaborative effort between researchers in academia, industry, and an NGO, with the following objectives: 1) compare eDNA detections with electrofishing when monitoring brook trout populations in a site of known occupancy, 2) compare existing eDNA collection methods, and 3) extend eDNA surveys to regions of unknown occupancy that could be of conservation concern (Hanlon Creek and Twelve Mile Creek, Ontario). First, eDNA sampling methods were validated with standard electrofishing. Water samples were filtered in tandem at each site using two commercially available eDNA samplers. The results suggest a significant difference in total eDNA capture and incidence of PCR inhibitors between the two autosamplers. Brook trout eDNA was detected at all locations in Hanlon Creek in September and November, as well as 5/6 sampling locations in Twelve Mile Creek. Brook trout signal in Hanlon Creek was stronger in November compared to September 2019, suggesting possible spawning activity. Brook trout eDNA was also detected in Twelve Mile Creek where brook trout were previously unreported. This study provides a technical validation for the use of eDNA in brook trout monitoring and illustrates the opportunity to use eDNA surveys in regulated settings to complement and improve conventional biomonitoring methods for the management of elusive species.

A segmentation-informed deep learning framework to register dynamic two-dimensional magnetic resonance images of the vocal tract during speech

ObjectiveDynamic magnetic resonance (MR) imaging enables visualisation of articulators during speech. There is growing interest in quantifying articulator motion in two-dimensional MR images of the vocal tract, to better understand speech production and potentially inform patient management decisions. Image registration is an established way to achieve this quantification. Recently, segmentation-informed deformable registration frameworks have been developed and have achieved state-of-the-art accuracy. This work aims to adapt such a framework and optimise it for estimating displacement fields between dynamic two-dimensional MR images of the vocal tract during speech. MethodsA deep-learning-based registration framework was developed and compared with current state-of-the-art registration methods and frameworks (two traditional methods and three deep-learning-based frameworks, two of which are segmentation informed). The accuracy of the methods and frameworks was evaluated using the Dice coefficient (DSC), average surface distance (ASD) and a metric based on velopharyngeal closure. The metric evaluated if the fields captured a clinically relevant and quantifiable aspect of articulator motion. ResultsThe segmentation-informed frameworks achieved higher DSCs and lower ASDs and captured more velopharyngeal closures than the traditional methods and the framework that was not segmentation informed. All segmentation-informed frameworks achieved similar DSCs and ASDs. However, the proposed framework captured the most velopharyngeal closures. ConclusionsA framework was successfully developed and found to more accurately estimate articulator motion than five current state-of-the-art methods and frameworks. SignificanceThe first deep-learning-based framework specifically for registering dynamic two-dimensional MR images of the vocal tract during speech has been developed and evaluated.

Effects of vessel traffic and ocean noise on gray whale stress hormones

Human use of marinescapes is rapidly increasing, especially in populated nearshore regions where recreational vessel traffic can be dense. Marine animals can have a physiological response to such elevated human activity that can impact individual health and population dynamics. To understand the physiological impacts of vessel traffic on baleen whales, we investigated the adrenal stress response of gray whales (Eschrichtius robustus) to variable vessel traffic levels through an assessment of fecal glucocorticoid metabolite (fGC) concentrations. This analysis was conducted at the individual level, at multiple temporal scales (1–7 days), and accounted for factors that may confound fGC: sex, age, nutritional status, and reproductive state. Data were collected in Oregon, USA, from June to October of 2016–2018. Results indicate significant correlations between fGC, month, and vessel counts from the day prior to fecal sample collection. Furthermore, we show a significant positive correlation between vessel traffic and underwater ambient noise levels, which indicates that noise produced by vessel traffic may be a causal factor for the increased fGC. This study increases knowledge of gray whale physiological response to vessel traffic and may inform management decisions regarding regulations of vessel traffic activities and thresholds near critical whale habitats.

Quantifying intra- and inter-species contact rates at supplemental feeding sites in Ethiopia to inform rabies maintenance potential of multiple host species.

Rabies, a multi-host pathogen responsible for the loss of roughly 59,000 human lives each year worldwide, continues to impose a significant burden of disease despite control efforts, especially in Ethiopia. However, how species other than dogs contribute to rabies transmission throughout Ethiopia remains largely unknown. In this study, we quantified interactions among wildlife species in Ethiopia with the greatest potential for contributing to rabies maintenance. We observed wildlife at supplemental scavenging sites across multiple landscape types and quantified transmission potential. More specifically, we used camera trap data to quantify species abundance, species distribution, and intra- and inter-species contacts per trapping night over time and by location. We derived a mathematical expression for the basic reproductive number (R0 ) based on within- and between-species contract rates by applying the next generation method to the susceptible, exposed, infectious, removed model. We calculated R0 for transmission within each species and between each pair of species using camera trap data in order to identify pairwise interactions that contributed the most to transmission in an ecological community. We estimated which species, or species pairs, could maintain transmission ( ) and which species, or species pairs, had contact rates too low for maintenance ( ). Our results identified multiple urban carnivores as candidate species for rabies maintenance throughout Ethiopia, with hyenas exhibiting the greatest risk for rabies maintenance through intra-species transmission. Hyenas and cats had the greatest risk for rabies maintenance through inter-species transmission. Urban and peri-urban sites posed the greatest risk for rabies transmission. The night-time hours presented the greatest risk for a contact event that could result in rabies transmission. Overall, both intra- and inter-species contacts posed risk for rabies maintenance. Our results can be used to target future studies and inform population management decisions.