A DETERMINANTS OF HEALTH CONCEPTUAL MODEL FOR FISH AND WILDLIFE HEALTH

The Importance of Baseline Health Surveillance Efforts in Freshwater Fish Conservation Using the Threatened Iberian Leuciscids as an Example

Freshwater fish species are experiencing the highest decline among vertebrates in this century. Although a great effort has been made to identify and tackle threats to the conservation of this taxa, several knowledge gaps still exist particularly for noncommercial endangered species, including considerations regarding fish health status. These species face deteriorating environmental conditions in their natural habitats that may lead to stress and increased risk for infectious disease outbreaks. Establishing health surveillance is crucial to identify and predict physiologic disruption in fish populations. Additionally, information retrieved may be used to direct targeted efforts to contribute to improving the conservation status of these species. We used threatened Iberian leuciscids as a case study to discuss the current knowledge regarding their health surveillance and to suggest recommendations for the establishment of practical health assessments that can benefit conservation plans for these species and be implemented in threatened or endangered freshwater fish species plans globally.

An integrative and multi-indicator approach for wildlife health applied to an endangered caribou herd

Assessing wildlife health in remote regions requires a multi-faceted approach, which commonly involves convenient samplings and the need of identifying and targeting relevant and informative indicators. We applied a novel wildlife health framework and critically assessed the value of different indicators for understanding the health status and trends of an endangered tundra caribou population. Samples and data from the Dolphin and Union caribou herd were obtained between 2015 and 2021, from community-based surveillance programs and from captured animals. We documented and categorized indicators into health determinants (infectious diseases and trace elements), processes (cortisol, pathology), and health outcomes (pregnancy and body condition). During a recent period of steep population decline, our results indicated a relatively good body condition and pregnancy rates, and decreasing levels of stress, along with a low adult cow survival. We detected multiple factors as potential contributors to the reduced survival, including Brucella suis biovar 4, Erysipelothrix rhusiopathiae and lower hair trace minerals. These results remark the need of targeted studies to improve detection and investigations on caribou mortalities. We also identified differences in health indicators between captured and hunter sampled caribou, highlighting the importance of accounting for sampling biases. This integrative approach that drew on multiple data sources has provided unprecedented knowledge on the health in this herd and highlights the value of documenting individual animal health to understand causes of wildlife declines.

Strengthening a One Health approach to emerging zoonoses

Given the enormous global impact of the COVID-19 pandemic, outbreaks of highly pathogenic avian influenza in Canada, and manifold other zoonotic pathogen activity, there is a pressing need for a deeper understanding of the human-animal-environment interface and the intersecting biological, ecological, and societal factors contributing to the emergence, spread, and impact of zoonotic diseases. We aim to apply a One Health approach to pressing issues related to emerging zoonoses, and propose a functional framework of interconnected but distinct groups of recommendations around strategy and governance, technical leadership (operations), equity, education and research for a One Health approach and Action Plan for Canada. Change is desperately needed, beginning by reorienting our approach to health and recalibrating our perspectives to restore balance with the natural world in a rapid and sustainable fashion. In Canada, a major paradigm shift in how we think about health is required. All of society must recognize the intrinsic value of all living species and the importance of the health of humans, other animals, and ecosystems to health for all.

Evaluating the use of hair as a non-invasive indicator of trace mineral status in woodland caribou (Rangifer tarandus caribou)

Trace mineral imbalances can have significant effects on animal health, reproductive success, and survival. Monitoring their status in wildlife populations is, therefore, important for management and conservation. Typically, livers and kidneys are sampled to measure mineral status, but biopsies and lethal-sampling are not always possible, particularly for Species at Risk. We aimed to: 1) determine baseline mineral levels in Northern Mountain caribou (Rangifer tarandus caribou; Gmelin, 1788) in northwestern British Columbia, Canada, and 2) determine if hair can be used as an effective indicator of caribou mineral status by evaluating associations between hair and organ mineral concentrations. Hair, liver, and kidney samples from adult male caribou (nHair = 31; nLiver, nKidney = 43) were collected by guide-outfitters in 2016-2018 hunting seasons. Trace minerals and heavy metals were quantified using inductively-coupled plasma mass spectrometry, and organ and hair concentrations of same individuals were compared. Some organ mineral concentrations differed from other caribou populations, though no clinical deficiency or toxicity symptoms were reported in our population. Significant correlations were found between liver and hair selenium (rho = 0.66, p<0.05), kidney and hair cobalt (rho = 0.51, p<0.05), and liver and hair molybdenum (rho = 0.37, p<0.10). These findings suggest that hair trace mineral assessment may be used as a non-invasive and easily-accessible way to monitor caribou selenium, cobalt, and molybdenum status, and may be a valuable tool to help assess overall caribou health.

Canadian wildlife health surveillance—patterns, challenges and opportunities identified by a scoping review

The protection and promotion of healthy wildlife populations is emerging as a shared goal among stakeholders in the face of unprecedented environmental threats. Accordingly, there are growing demands for the generation of actionable wildlife health information. Wildlife health surveillance is a connected system of knowledge that generates data on a range of factors that influence health. Canada recently approved the Pan-Canadian Approach to Wildlife Health that describes challenges facing wildlife health programs and provides a path forward for modernizing our approach. This scoping review was undertaken to describe the range of peer-reviewed Canadian wildlife health surveillance literature within the context of the challenges facing wildlife health programs and to provide a quantitative synthesis of evidence to establish baselines, identify gaps, and inform areas for growth. This review describes patterns related to species, location, authorship/funding, objectives, and methodology. Five areas are identified that have the potential to propel the field of wildlife health: representativeness, expanded/diversified collaboration, community engagement, harmonization, and a shift to a solutions-focused and One Health mindset. This scoping review provides a synopsis of 10 years of Canadian wildlife health surveillance, challenges us to envision the future of successful wildlife health surveillance, and provides a benchmark from which we can measure change.

Landscape condition influences energetics, reproduction, and stress biomarkers in grizzly bears

Environmental change has been shown to influence mammalian distribution, habitat use, and behavior; however, few studies have investigated the impact on physiological function. This study aimed to determine the influence of landscape condition on the expression of target proteins related to energetics, reproduction, and stress in grizzly bears. We hypothesized that changes in landscape condition explains protein expression. Skin biopsies were collected from free-ranging grizzly bears in Alberta, Canada from 2013-2019 (n = 86 individuals). We used an information theoretic approach to develop 11 a priori candidate generalized linear mixed models to explain protein expression. We compared models using Akaike Information Criteria (AICc) weights and averaged models with ΔAICc < 2 for each protein. Food resources, represented by increased distance to coal mines and decreased crown closure, positively influenced energetic proteins (adiponectin and alpha-1-acid glycoprotein). Proteins related to reproduction (ceruloplasmin and serpin B5) were positively associated with increased wetland and upland food resources in addition to movement, but negatively associated with increased distance to roads. One stress related protein, complement C3, was positively influenced by increased percent conifer. Given the need to detect emerging threats to wildlife, we suggest the assessment of physiological function will lead to improved monitoring of species in rapidly changing landscapes.

Environmental Factors Influencing the Occurrence of Unhealthy Tapirs in the Southern Yucatan Peninsula

Information about the effects of environmental degradation on the health of terrestrial forest wildlife is limited, especially for rare species. In this study, we analyse the influence of ecological factors such as landscape characteristics and seasonality on the health status of Baird's tapirs in Calakmul, Mexico. We collected georeferenced photographic records of healthy (n = 32) and unhealthy (n = 22) tapirs from 2008 to 2019 and characterized landscape composition around each record at three spatial scales (circular buffers of 1, 2 and 3-km radii according to Baird's tapir home ranges). Our logistic model building process consisted in selecting the best spatial scale for each landscape cover class, before including them along with distance to human settlements and seasonality in a full model. The model that best explained the occurrence of unhealthy tapirs included the percentage of agriculture within a 1-km radius. This study hints at the negative effect that land-use change to agriculture occurring in Calakmul might have on tapir health, with 95.45% of unhealthy tapirs recorded in such landscapes. Further studies should investigate the proximate determinants of tapir health in anthropogenic landscapes, which might be linked to stress or to contact with domestic animals.

Is Fisheries and Oceans Canada policy receptive to a new Pacific salmon health perspective?

The concept of health permeates priorities and policies for managing wild Pacific salmon ( Oncorynchus spp.). Regulatory agencies rely largely on salmon abundance and (or) the absence of pathogens to declare if a population is healthy. Our goal was to determine if there was a receptive policy environment within Fisheries and Oceans Canada (DFO) to adopt a cumulative effects perspective of health. We used a previously developed health model along with a multiple streams framework and a narrative review of DFO policy to see how fish health was situated in DFO’s salmon management problems, policy, and politics. We discovered that a cumulative effects perspective was consistent with policy goals and priorities. DFO’s guiding principles and responsibilities for aquatic animal health were spread across multiple policies and regulations. There were no processes or people responsible for integrating information and activities. The use of the word health in policies and planning without a consistent definition meant that DFO could not explicitly assess if it has reached its management target of healthy salmon. An option for transitioning to cumulative effects perspective is to adopt a healthy public policy perspective and processes to integrate the diverse information linked to social and environmental determinants of health.