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  • OPEN ACCESS
    Fluctuating water levels influence access to critical habitats for threatened Cowichan Lake lamprey
    FACETS • Vol. 5 • No. 1 • pp. 488 - 502
    Cowichan Lake lamprey (Entosphenus macrostomus) is a threatened species resident to Mesachie Lake, Cowichan Lake, and adjoining Bear Lake and their major tributaries in British Columbia. Decreases in trapping success have created concerns that the population is declining. Some potential threats include water use, climate change, and management actions. Owing to the absence of long-term data on population trends, little information is available to estimate habitat quality and factors that influence it. We sought to fill this gap by examining associations between habitat area and variables representing suspected key drivers of habitat availability. Critical habitat areas were imaged using an unmanned aerial vehicle over a period of three years at three sites at Cowichan Lake and a subsequent habitat area was classified. Meteorological and anthropogenic controls on habitat area were investigated through automatic relevance detection regression models. The major driver of habitat area during the critical spawning period was water level during the storage season, which also depends on the meteorological variables and anthropogenic control. It is recommended that regulation of the weir should aim to ensure that the water level remains above the 1 m mark, which roughly equates to the 67% coverage of water on the habitat area used for spawning.
  • OPEN ACCESS
    Variation in isotopic niche, digestive tract morphology, and mercury concentrations in two sympatric waterfowl species wintering in Atlantic Canada
    FACETS • Vol. 5 • No. 1 • pp. 393 - 408
    Sympatric communities of organisms may exploit different ecological niches to avoid intra- and interspecific competition. We examined the isotopic niches of American black ducks (Anas rubripes) and mallards (A. platyrhynchos) wintering in coastal and urban areas of Atlantic Canada and compared isotopic niche with digestive tract morphologies and blood mercury (Hg) concentrations. Isotopic niche width (for δ13C and δ15N) varied between the three groups of ducks studied, with coastally foraging black ducks exhibiting the widest isotopic niche, followed by coastal mallards, while urban feeding black ducks had a narrow isotopic niche. These niche differences had physical and chemical consequences: coastal black ducks had longer digestive tracts, a larger range in gizzard sizes, and higher and more variable Hg concentrations than urban black ducks and coastal mallards. This plasticity in ecological niche may reduce competition among and within species, and subsequently explain why winter numbers of black ducks and mallards have increased in Atlantic Canada.
  • OPEN ACCESS
    Role of green alder in boreal conifer growth: competitor or facilitator?
    FACETS • Vol. 5 • No. 1 • pp. 166 - 181
    Sustainable forest management implies successful regeneration after disturbances. Low N availability and competition can, however, limit tree establishment in boreal ecosystems. To develop silviculture strategies that maintain productivity in such context, we established a field trial in northern Québec, Canada. We evaluated if a companion N2-fixing species (Alnus alnobetula) promotes or hinders Picea mariana and Pinus banksiana establishment over six growing seasons. We tested if Alnus has a facilitation effect through nutritional processes and a competition effect through light interception. Foliar stable nitrogen isotope ratio (δ15N = 15N/14N, ‰) results confirmed that Alnus obtains a substantial part of its N through biological fixation and represents an N source in this system. Although we did not observe increased foliar N concentrations in either conifer species in the presence of Alnus, Pinus growth was nonetheless higher in presence of Alnus, whereas no difference was observed for Picea. In the plots where Alnus cohabited with the conifers, the former had a negative impact on seedling growth, suggesting a significant competition for light. Overall, the net effect of Alnus was positive for Pinus and neutral for Picea. Our results have significant implications for silviculture in N-limited systems, especially in the context of climate change that imposes increased levels of stress on regeneration.
  • OPEN ACCESS
    Bat bites and rabies: the Canadian scene
    FACETS • Vol. 5 • No. 1 • pp. 367 - 380
    Bats are susceptible to rabies. Although bats may appear to be asymptomatic carriers of rabies for a few days, eventually they fall ill to the viral infection and die. Two of at least four bat-specific variants of rabies virus in Canada have killed humans. Rabies is usually transmitted by biting, but bats are small mammals so their bites may go unnoticed. People exposed to rabid animals should receive postexposure prophylaxis (PEP). With 60 known human deaths from 1950 to 2009, rabies is rare in Canada and the United States of America compared with India where it kills over 100 people annually. In Asia and Africa, most human rabies is acquired from dog bites. In Brazil, dog and bat bites together account for >80% of human rabies. In Canada, rabies is a disease primarily confined to wildlife (foxes, racoons, skunks, and bats). The public image of bats is negatively affected by their association with diseases. Too often bats are victimized by allegations of their role in deadly diseases such as rabies, Ebola, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). In general, bats are not dangerous, but humans should seek treatment if they are bitten by one. (Graphical abstract shows a 4-g elegant myotis biting MBF’s finger—photo by Sherri and Brock Fenton.)
  • OPEN ACCESS
    Sublethal effects of wild-type and a vIF-2α-knockout Frog virus 3 on postmetamorphic wood frogs (Rana sylvatica): potential for a stage-specific reservoir
    FACETS • Vol. 5 • No. 1 • pp. 738 - 757
    Ranaviruses have been associated with rising numbers of mass die-offs in amphibian populations around the globe. However, most studies on ranaviruses to date focused on larval amphibians. To assess the role of postmetamorphic amphibians in the epidemiology of ranaviruses and to determine the role of viral immune-suppression genes, we performed a bath-exposure study on post-metamorphic wood frogs (Rana sylvatica) using environmentally relevant concentrations of wild-type Frog virus 3 (WT FV3), and a gene-knockout mutant (KO FV3), deficient for the putative immune-suppression gene vIF-2α. We observed a 42% infection rate and 5% mortality across the virus challenges, with infection rates and viral loads following a dose-dependent pattern. Individuals exposed to the knockout variant exhibited significantly decreased growth and increased lethargy compared with wild-type treatments. Although 85% of exposed individuals exhibited common signs of ranavirosis throughout the experiment, most of these individuals did not exhibit signs of infection by 40 d post-exposure. Overall, we showed that even a single short time exposure to environmentally relevant concentrations of ranavirus may cause sublethal infections in postmetamorphic amphibians, highlighting the importance of this life stage in the epidemiology of ranaviruses. Our study also supports the importance of the vIF-2α gene in immune-suppression in infected individuals.
  • OPEN ACCESS
    Is the cure worse than the disease? Comparing the ecological effects of an invasive aquatic plant and the herbicide treatments used to control it
    FACETS • Vol. 5 • No. 1 • pp. 353 - 366
    Invasive species are known to have negative ecological effects. However, few studies have evaluated the impacts of invasive species relative to the effects of invasive species control, thereby limiting our ability to make informed decisions considering the benefits and drawbacks of a given management approach. To address this gap, we compared the ecological effects of the invasive aquatic plant Eurasian watermilfoil (Myriophyllum spicatum L.) with the effects of lake-wide herbicide treatments used for M. spicatum control using aquatic plant data collected from 173 lakes in Wisconsin, USA. First, a pre–post analysis of aquatic plant communities found significant declines in native plant species in response to lake-wide herbicide treatment. Second, multi-level modeling using a large data set revealed a negative association between lake-wide herbicide treatments and native aquatic plants, but no significant negative effect of invasive M. spicatum. Taken together, our results indicate that lake-wide herbicide treatments aimed at controlling M. spicatum had larger effects on native aquatic plants than did the target of control—invasive M. spicatum. Our comparison reveals an important management tradeoff and encourages careful consideration of how we balance the real and perceived impacts of invasive species and the methods used for their control.
  • OPEN ACCESS
    Sustaining Canadian marine biodiversity: Policy and statutory progress
    FACETS • Vol. 5 • No. 1 • pp. 264 - 288
    A 2012 Expert Panel Report on marine biodiversity by the Royal Society of Canada (RSC) concluded that Canada faced significant challenges in achieving sustainable fisheries, regulating aquaculture, and accounting for climate change. Relative to many countries, progress by Canada in fulfilling international obligations to sustain biodiversity was deemed poor. To track progress by Canada since 2012, the RSC struck a committee to track policy and statutory developments on matters pertaining to marine biodiversity and to identify policy challenges, and leading options for implementation that lie ahead. The report by the Policy Briefing Committee is presented here. It concluded that Canada has made moderate to good progress in some areas, such as prioritization of oceans stewardship and strengthening of the evidentiary use of science in decision-making. Key statutes were strengthened through amendments, including requirements to rebuild depleted fisheries (Fisheries Act) and new means of creating marine protected areas (Oceans Act) that allowed Canada to exceed its international obligation to protect 10% of coastal and marine areas by 2020. Public release of mandate letters has strengthened ministerial accountability. However, little or no progress has been made in reducing regulatory conflict with Fisheries and Oceans Canada (DFO), decreasing ministerial discretion under the Fisheries Act, clarifying the role of science in sustainable fisheries policy, and accounting for climate change. Five future policy challenges are identified: (1) Ensure climate change impacts and projections are incorporated into ocean-related decision making and planning processes; (2) Resolve DFO’s regulatory conflict to conserve and exploit biodiversity; (3) Limit ministerial discretionary power in fisheries management decisions; (4) Clarify ambiguities in how the Precautionary Approach is applied in sustainable fisheries policy; and (5) Advance and implement marine spatial planning. Since 2012, there has been progress in recovering and sustaining the health of Canada’s oceans. Failure to further strengthen biodiversity conservation threatens the capacity of Canada’s oceans to provide ecosystem services that contribute to the resilience of marine life and the well-being of humankind. Unprecedented and enduring changes in the ocean caused by climate change have made the achievement of meaningful progress all the more urgent.
  • OPEN ACCESS
    Amphibian ranaviruses in Europe: important directions for future research
    FACETS • Vol. 5 • No. 1 • pp. 598 - 614
    Ranaviruses are an emerging group of pathogens capable of infecting all cold-blooded vertebrates. In Europe, ranaviruses pose a particularly potent threat to wild amphibian populations. Since the 1980s research on amphibian-infecting ranaviruses in Europe has been growing. The wide distribution of amphibian populations in Europe, the ease with which many are monitored, and the tractable nature of counterpart ex situ experimental systems have provided researchers with a unique opportunity to study many aspects of host–ranavirus interactions in the wild. These characteristics of European amphibian populations will also enable researchers to lead the way as the field of host–ranavirus interactions progresses. In this review, we provide a summary of the current key knowledge regarding amphibian infecting ranaviruses throughout Europe. We then outline important areas of further research and suggest practical ways each could be pursued. We address the study of potential interactions between the amphibian microbiome and ranaviruses, how pollution may exacerbate ranaviral disease either as direct stressors of amphibians or indirect modification of the amphibian microbiome. Finally, we discuss the need for continued surveillance of ranaviral emergence in the face of climate change.
  • OPEN ACCESS
    An examination of the Iridovirus core genes for reconstructing Ranavirus phylogenies
    FACETS • Vol. 5 • No. 1 • pp. 523 - 533
    Ranaviruses are globally emerging infections of poikilothermic vertebrates and belong to the viral family Iridoviridae. The six species of ranaviruses are responsible for unknown numbers of infections and disease and mortality events around the world in amphibians, fish, and reptiles. Genomic investigations have shown that there are 24 core genes shared by all iridoviruses. In this study, we examine the utility of each of these genes in reconstructing phylogenetic relationships across six species of Ranavirus. We also performed dot-plot analysis for the 17 isolates in the study. For large-scale differentiation, using the major capsid protein gene creates a tree similar to the whole genome tree. Other comparable genes include open reading frame (ORF) 19R (a serine–theonine protein kinase) and ORF 88R (Erv I/Alr Family protein). The poorest candidate for phylogenetic reconstruction, due to high homology, was ORF 1R (a putative replication factor and (or) DNA binding-packing protein). There are a plethora of genes that may be useful to examine phylogenies at smaller scales (e.g., to examine local adaptation); however, they do not necessarily belong to the set of highly conserved core genes.
  • OPEN ACCESS
    Discovery of granulocyte-lineage cells in the skin of the amphibian Xenopus laevis
    FACETS • Vol. 5 • No. 1 • pp. 571 - 597
    The ranavirus Frog Virus 3 (FV3) and the chytrid fungus Batrachochytrium dendrobatidis (Bd) are significant contributors to the global amphibian declines and both pathogens target the amphibian skin. We previously showed that tadpoles and adults of the anuran amphibian Xenopus laevis express notable levels of granulocyte chemokine genes (cxcl8a and cxcl8b) within their skin and likely possess skin-resident granulocytes. Presently, we show that tadpole and adult X. laevis indeed possess granulocyte-lineage cells within their epidermises that are distinct from their skin mast cells, which are found predominantly in lower dermal layers. These esterase-positive cells responded to (r)CXCL8a and rCXCL8b in a concentration- and CXCR1/CXCR2-dependent manner, possessed polymorphonuclear granulocyte morphology, granulocyte marker surface staining, and exhibited distinct immune gene expression from conventional granulocytes. Our past work indicates that CXCL8b recruits immunosuppressive granulocytes, and here we demonstrated that enriching esterase-positive skin granulocytes with rCXCL8b (but not rCXCL8a) may increase tadpole susceptibility to FV3 and adult frog susceptibility to Bd. Furthermore, pharmacological depletion of skin-resident granulocytes increased tadpole susceptibility to FV3. This manuscript provides new insights into the composition and roles of immune cells within the amphibian skin, which is a critical barrier against pathogenic contributors to the amphibian declines.
  • OPEN ACCESS
    Ranaviruses in captive and wild Australian lizards
    FACETS • Vol. 5 • No. 1 • pp. 758 - 768
    Ranaviral infections have been associated with mass mortality events in captive and wild amphibian, fish, and reptile populations globally. In Australia, two distinct types of ranaviruses have been isolated: epizootic haematopoietic necrosis virus in fish and a Frog virus 3-like ranavirus in amphibians. Experimental studies and serum surveys have demonstrated that several Australian native fish, amphibian, and reptile species are susceptible to infection and supported the theory that ranavirus is naturally circulating in Australian herpetofauna. However, ranaviral infections have not been detected in captive or wild lizards in Australia. Oral-cloacal swabs were collected from 42 wild lizards from northern Queensland and 83 captive lizards from private collections held across three states/territories. Samples were tested for ranaviral DNA using a quantitative PCR assay. This assay detected ranaviral DNA in 30/83 (36.1%) captive and 33/42 (78.6%) wild lizard samples. This is the first time molecular evidence of ranavirus has been reported in Australian lizards.
  • OPEN ACCESS
    Temperature-dependent infection of freshwater turtle hatchlings, Emydura macquarii krefftii, inoculated with a ranavirus isolate (Bohle iridovirus, Iridoviridae)
    FACETS • Vol. 5 • No. 1 • pp. 821 - 830
    Fish, amphibians, and reptiles exhibit temperature-dependent ranaviral disease. We performed an experimental infection at four different environmental temperatures (16, 22, 28, and 34 °C) to investigate the effect of temperature on ranaviral infection in Krefft’s turtle (Emydura macquarii krefftii). Infection rates and viral loads were determined by quantitative polymerase chain reaction to detect ranaviral DNA in liver samples at 21 d postexposure. The rate of infection differed across the temperature treatment groups. Infection rates were 44%, 90%, 60%, and 10% for the 16, 22, 28, and 34 °C temperature groups, respectively. Highest viral load was observed in the 28 °C temperature group, and there was a statistically significant difference in viral load between the 16 and 28 °C temperature groups (p = 0.027). Based on the results of this study, the temperature of maximal infection rate for ranaviral infection in Krefft’s river turtles is estimated to be 23.2 °C (SD = 4.5). The findings of this study can inform management decisions in terms of disease control and treatment and form a platform for modelling disease outbreaks.
  • OPEN ACCESS
    Global patterns of ranavirus detections
    FACETS • Vol. 6 • pp. 912 - 924
    Ranaviruses are emerging pathogens of poikilothermic vertebrates. In 2015 the Global Ranavirus Reporting System (GRRS) was established as a centralized, open access, online database for reports of the presence (and absence) of ranavirus around the globe. The GRRS has multiple data layers (e.g., location, date, host(s) species, and methods of detection) of use to those studying the epidemiology, ecology, and evolution of this group of viruses. Here we summarize the temporal, spatial, diagnostic, and host-taxonomic patterns of ranavirus reports in the GRRS. The number, distribution, and host diversity of ranavirus reports have increased dramatically since the mid 1990s, presumably in response to increased interest in ranaviruses and the conservation of their hosts, and also the availability of molecular diagnostics. Yet there are clear geographic and taxonomic biases among the reports. We encourage ranavirus researchers to add their studies to the portal because such collation can provide collaborative opportunities and unique insights to our developing knowledge of this pathogen and the emerging infectious disease that it causes.
  • OPEN ACCESS
    Spatial distribution and conservation hotspots of mammals in Canada
    FACETS • Vol. 5 • No. 1 • pp. 692 - 703
    High-latitude countries often contain the polar range edge of species that are common farther south, potentially focusing national conservation efforts toward range-edge populations. The global conservation value of edge populations is controversial, but if they occur where biodiversity is high, there need not be trade-offs in protecting them. Using 152 of 158 terrestrial mammal species in Canada, we tested how species’ distributions relate to their national conservation status and total mammal richness. We found that half of “Canadian” mammals had <20% of their global range in Canada. National threat status was strongly associated with range area; mammals considered “at risk” had 42% smaller Canadian ranges than mammals considered secure. However, after accounting for range area, taxa with smaller proportions of their global range in Canada were not more likely to be considered at risk, suggesting edge populations are not inherently more vulnerable. When we calculated mammal diversity across Canada (100 × 100 km grid cells), we found that hotspots of at-risk or range-edge mammals were twice as species rich as nonhotspot cells, containing up to 44% of Canadian mammal diversity per grid cell. Our results suggest that protecting areas with the most at-risk or range-edge mammals would simultaneously protect habitat for many species currently deemed secure.
  • OPEN ACCESS
    Ten simple rules to facilitate evidence implementation in the environmental sciences
    FACETS • Vol. 5 • No. 1 • pp. 642 - 650
    There is a gap between fundamental science and managers. There are many general solutions including the need to better leverage the primary scientific literature for decision-making. Herein, we provide a list of 10 simple rules to support environmental management through better scientific writing and suggest practices for more transparent publications. These rules can also be used as a checklist for reusing the primary literature when searching for relevant evidence in the environmental sciences. We need to better structure knowledge in papers for connections within sustainable societies.
  • OPEN ACCESS
    Extreme rainfall drives early onset cyanobacterial bloom
    FACETS • Vol. 5 • No. 1 • pp. 899 - 920
    The increasing prevalence of cyanobacteria-dominated harmful algal blooms is strongly associated with nutrient loading and changing climatic patterns. Changes to precipitation frequency and intensity, as predicted by current climate models, are likely to affect bloom development and composition through changes in nutrient fluxes and water column mixing. However, few studies have directly documented the effects of extreme precipitation events on cyanobacterial composition, biomass, and toxin production. We tracked changes in a eutrophic reservoir following an extreme precipitation event, describing an atypically early toxin-producing cyanobacterial bloom and successional progression of the phytoplankton community, toxins, and geochemistry. An increase in bioavailable phosphorus by more than 27-fold in surface waters preceded notable increases in Aphanizomenon flos-aquae throughout the reservoir approximately 2 weeks postevent and ∼5 weeks before blooms typically occur. Anabaenopeptin-A and three microcystin congeners (microcystin-LR, -YR, and -RR) were detected at varying levels across sites during the bloom period, which lasted between 3 and 5 weeks. These findings suggest extreme rainfall can trigger early cyanobacterial bloom initiation, effectively elongating the bloom season period of potential toxicity. However, effects will vary depending on factors including the timing of rainfall and reservoir physical structure.
  • OPEN ACCESS
    Weighing the importance of animal body size in traditional food systems
    FACETS • Vol. 7 • pp. 286 - 318
    Traditional food systems based on harvest from the local environment are fundamental to the well-being of many communities, but their security is challenged by rapid socio-ecological change. We synthesized literature and data describing how a fundamental form of biodiversity, animal body size, contributes to the security of traditional food systems through relationships with species availability, accessibility, adequacy, and use. We found larger vertebrate species were more available, accessible, and used on a per kilogram basis, particularly for mammals. Conversely, larger species were no more or less adequate from a combined nutritional, health, and cultural perspective. Larger species represented more biomass, and this biomass required less time to harvest, with greater but more variable mean caloric returns over time. Smaller species provided more consistent caloric returns and were harvested during documented shortages of prey. This reliance on species with a range of body sizes is consistent with optimal foraging theory and the evolutionary value of flexibility, and highlights the importance of a biodiverse pool of species for traditional food security in times of change. Our synthesis of published literature and data highlights the many socio-ecological correlates of species size and how these relate to the security of traditional food systems.
  • OPEN ACCESS
    Lack of molecular detection of frog virus 3-like ranavirus (FV3) in mosquitoes during natural outbreak and nonoutbreak conditions
    FACETS • Vol. 5 • No. 1 • pp. 812 - 820
    Ranaviruses are worldwide pathogens of ectothermic vertebrates that can threaten herptile conservation efforts. Identifying transmission routes is critical for understanding disease ecology and promoting species conservation. Frog virus 3 (FV3) DNA was detected in mosquitoes during a ranavirus outbreak in semicaptive box turtles, but the role that insect vectors play under natural conditions is unknown. To address this knowledge gap, we collected mosquito species known to take blood meals from reptiles and amphibians (Aedes canadensis, Culex erraticus, Culex territans, and Uranotaenia sapphirina) from mid-May to early August, 2014, at four study sites in Vermilion County, Illinois, two of which had historic or ongoing FV3 outbreaks in box turtles and amphibians. Mosquitoes were batched by date and species, DNA was extracted, and quantitative polymerase chain reaction was performed for detection of FV3. FV3 was not detected despite one of the sites having an active FV3 outbreak during the study period. Our findings indicate that FV3 detection is uncommon in mosquitoes during outbreak and nonoutbreak conditions at these sites in Illinois. Thus, we cannot establish that mosquitoes contribute to transmission during natural mortality events without performing further studies.
  • OPEN ACCESS
    Comparing metabarcoding and morphological approaches to identify phytoplankton taxa associated with harmful algal blooms
    FACETS • Vol. 5 • No. 1 • pp. 784 - 811
    Molecular techniques are expected to be highly useful in detecting taxa causing harmful algal blooms (HABs). This is the first report in Canada evaluating HABs-related species identification using a combination of morphological and molecular approaches. Microscopy, quantitative polymerase chain reaction (qPCR), and metabarcoding with multiple markers (i.e., 16S, 18S-dinoflagellate and 18S-diatom, large subunit (28S) rDNA) were applied on samples (n = 54) containing suspected harmful algae (e.g., Alexandrium spp., Chattonella sp., Chrysochromulina spp., Dictyocha spp., Heterosigma akashiwo, Protoceratium reticulatum, Pseudochattonella verruculosa, Pseudo-nitzschia spp., Pseudopedinella sp.). Owing to methodology limitations, qPCR result interpretation was limited, although good detectability occurred using previously published assays for Alexandrium tamarense, H. akashiwo, and P. verruculosa. Overall, the multiple-marker metabarcoding results were superior to the morphology-based methods, with the exception of taxa from the silicoflagellate group. The combined results using both 18S markers and the 28S marker together closely corresponded with morphological identification of targeted species, providing the best overall taxonomic coverage and resolution. The most numerous unique taxa were identified using the 18S-dinoflagellate amplicon, and the best resolution to the species level occurred using the 28S amplicon. Molecular techniques are therefore promising for HABs taxa detection but currently depend on deploying multiple markers for metabarcoding.
  • OPEN ACCESS
    COVID-19 and threats to bats
    FACETS • Vol. 5 • No. 1 • pp. 349 - 352