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  • OPEN ACCESS
    The long-term effects of water resource development on blood mercury levels and the trophic ecology of Namew (lake sturgeon, Acipenser fulvescens)
    FACETS • Vol. 9 • pp. 1 - 13
    Water resource development can alter the movement and ecology of sturgeons. We studied total (THg) and methylmercury concentrations in whole blood sampled non-lethally from namew (Moose Cree L-dialect, lake sturgeon, Acipenser fulvescens), an endangered and culturally important subsistence fish. Namew were sampled from two tributaries within the Moose Cree Homeland: the Lower Mattagami River (an impacted system with four hydroelectric generating stations) and the North French River (a reference system that is free-flowing system with no development). Results indicated namew from the North French River had higher blood [THg] than those from the Mattagami River. Further modeling showed that trophic position was the primary driver of these differences, with North French namew having the highest nitrogen isotope ratios. Based on further isotope modeling, crayfish were major components of namew diet at all sites, while other prey items differed between sites. Specifically, namew with unobstructed access to the lower watershed had notably more enriched isotope values when compared to the freshwater benthic macroinvertebrates sampled, implying that other prey not captured herein may contribute to their diets and [THg]. Overall, we found differences in namew’s trophic ecology but no elevation in blood mercury levels at a site impacted by hydroelectric operations 60+ years post-impoundment.
  • OPEN ACCESS
    Modelling the dispersion of infectious salmon anemia virus from Atlantic salmon farms in the Quoddy Region of New Brunswick, Canada and Maine, USA
    FACETS • Vol. 9 • pp. 1 - 19
    Pathogen dispersal from infected aquaculture sites into the surrounding ocean poses risks of infection to wild and farmed species, but is difficult to predict. This study aimed to build a framework using an ocean circulation and a particle tracking model in conjunction with a dynamic infection model and a virus inactivation model to simulate the dispersal of the infectious salmon anemia virus (ISAV) from Atlantic salmon farms. Simulated particles were released from hypothetically infected farms and advected by modelled currents. Inactivation of viral cohorts by ambient ultraviolet radiation and natural microbial communities was simulated during advection. Simulations showed that ISAV concentration varied spatiotemporally with the progression of the outbreak, current speed and direction, tidal elevation amplitude, and environmental decay. Connectivity among aquaculture sites varied in relation to seaway distances, though simulations showed that connectivity can also be asymmetrical between farm sites. Sensitivity analyses showed that the dispersal of ISAV was moderately sensitive to uncertainty associated with the viral decay model, highlighting the importance of obtaining accurate estimates of inactivation rates of ISAV. This framework provides an approach to simulate waterborne viral transmission that considers the biology and epidemic features of significance for pathogens and the dynamic conditions of the ocean.
  • OPEN ACCESS
    A pilot bioavailable strontium isotope baseline map of Southern British Columbia, Canada
    FACETS • Vol. 9 • pp. 1 - 11
    Strontium isotopes are used for provenience and mobility studies in archaeology, ecology, and forensic studies, and rely on accurate baseline maps that are used to compare and interpret human and animal strontium ratios. Here, we present a bioavailable 87Sr/86Sr map, also called an isoscape, for southern British Columbia derived from modern plant samples’ 87Sr/86Sr ratios. We sampled 67 medium root depth plants over a 900 km transect from the southern BC coast to inland BC to capture the natural 87Sr/86Sr ratios of plants along the four major geological belts in British Columbia. Non-parametric Kruskal–Wallis and pairwise Wilcox tests were used to examine whether the geological belts had statistically significant mean differences. It was found that the province could be effectively divided into east and west, with the Coastal–Intermontane and Omineca–Foreland regions having statistically different means from each other. 87Sr/86Sr ratios had statistically significant relationships with salt deposition, volcanic deposition, and mean age of the underlying lithology. Generally, 87Sr/86Sr ratios increased with distance from the coast as the atmospheric input of radiogenic strontium from marine-derived rainwater decreased and the input of radiogenic strontium isotopes from the underlying geology of the Rockies in the far east of the province increased.
  • OPEN ACCESS
    Effect of acclimation temperature on thermal tolerance between American lobster (Homarus americanus) collected in different lobster fishing areas in Atlantic Canada
    FACETS • Vol. 9 • pp. 1 - 9
    The American lobster fishery is the most economically significant commercial fishery in Atlantic Canada and takes place in waters that are warming due to climate change. Lobster are poikilotherms that tolerate a wide range of seasonal temperatures with an optimal range of 12–18 °C. Lobster in the Canadian Maritimes may be naturally acclimated to a wide range of temperatures and thus, could have a wide range of thermal tolerance that may be distinct across regions. The present study used non-invasive open-source tools to explore differences in thermal tolerance in real time between geographically separated lobster populations from around the Canadian Maritimes. Lobsters were acquired from six lobster fishing areas in the Canadian Maritimes and acclimated to either warm (15 °C) or cold (5 °C) water for two weeks before the onset of thermal trials. Geographic origin was not a significant predictor of estimated thermal maximum, while acclimation temperature was a significant predictor. These results suggest that thermal tolerance is more strongly linked to acclimation temperature than to geographic region.
  • OPEN ACCESS
    Time to treat the climate and nature crisis as one indivisible global health emergency
      FACETS • Vol. 8 • pp. i - iii
    • OPEN ACCESS
      Transport does not influence maximum metabolic rate or thermal tolerance of endangered redside dace (Clinostomus elongatus)
      FACETS • Vol. 9 • pp. 1 - 9
      Reintroduction is an important tool in the conservation and recovery of aquatic species at risk. However, components of the reintroduction process such as transportation have the potential to induce physiological stress and the extent to which preparatory techniques can mitigate this stress is poorly understood in small-bodied fishes. To address this concern, we studied the effect of transport on two fitness-related performance measures: maximum metabolic rate and thermal tolerance in redside dace (Clinostomus elongatus), an imperilled small-bodied stream fish native to eastern North America. Prior to transportation, we manipulated the body condition of redside dace over a 12-week period, by providing either low (1% of their total body mass) or high (2% of their total body mass) rations. The goal of this manipulation was to influence body condition, as higher body condition can enhance physiological performance. Subsequently, redside dace were transported for varying durations: 0, 3, and 6 h. Following transportation, we measured maximum metabolic rate (µmol/h) and thermal tolerance (CTmax, °C). Our results indicate that neither transport nor body condition had a significant effect on maximum metabolic rate or thermal tolerance (CTmax). These findings provide preliminary evidence that redside dace can physiologically tolerate transport based on the endpoints measured and this information may possibly be extended to other small-bodied fish, for which information is lacking.
    • OPEN ACCESS
      An integrated assessment of impacts to ecosystem services associated with prairie pothole wetland drainage quantifying wide-ranging losses
      FACETS • Vol. 9 • pp. 1 - 15
      In many regions, a tradeoff exists between draining wetlands to support the expansion of agricultural land, and conserving wetlands to maintain their valuable ecosystem services. Decisions about wetland drainage are often made without identifying the impacts on the services these systems provide. We address this gap through a novel assessment of impacts on ecosystem services via wetland drainage in the Canadian prairie landscape. Draining pothole wetlands has large impacts, but sensitivity varies among the indicators considered. Loss of water storage increased the magnitude of median annual flows, but absolute increases with drainage were higher for larger, less frequent events. Total phosphorus exports increased in concert with streamflow. Our analysis suggested disproportionate riparian habitat losses with the first 30% of wetland area drained. Dabbling ducks and wetland-associated bird abundances respond strongly to the loss of small wetland ponds; abundances were predicted to decrease by half with the loss of only 20%–40% of wetland area. This approach to evaluating changes to key wetland ecosystem services in a large region where wetland drainage is ongoing can be used with an economic valuation of the drainage impacts, which should be weighed against the benefits associated with agricultural expansion.
    • OPEN ACCESS
      The effect of riffle restoration on the recovery of endangered Nooksack Dace (Rhinichthys cataractae sp. cataractae)
      FACETS • Vol. 9 • pp. 1 - 15
      The Nooksack Dace (Rhinichthys cataractae sp. cataractae) is a federally endangered riffle specialist endemic to the lower Fraser Valley of British Columbia, Canada, with historic population declines associated with riffle loss from stream dredging, channelization, and excessive sediment inputs. To assess the effectiveness of riffle restoration as a recovery strategy, gravel and cobble riffles were constructed in two replicate tributaries of the Nooksack River as a before-after-control-impact experiment, measuring dace abundance, substrate composition, and invertebrate biomass before and one year after restoration. Nooksack Dace density increased significantly in cobble (but not gravel) treatments relative to control riffles. Dace abundance was strongly associated with increased availability of interstitial refuges rather than substrate effects on invertebrate prey abundance, suggesting that interstitial space limits adult dace abundance. Young-of-the-year dace were not observed in one of the two restored streams despite riffle restoration, indicating increased dace density due to aggregation in higher-quality restored riffles. This recruitment limitation indicates persistence of a population bottleneck at an early life history stage that is not addressed by successful restoration of adult riffle habitat.
    • OPEN ACCESS
      Bull kelp (Nereocystis luetkeana) growth rates as climate stress indicators for Canada’s Pacific coast
      FACETS • Vol. 9 • pp. 1 - 19
      Primary producers’ growth rates are ideal bioindicators of changing climate due to their sensitivity to environmental conditions. On the Central Coast of British Columbia, we assessed growth rates of Nereocystis luetkeana, a canopy-forming annual kelp, by assessing baseline variability in growth rates and their response to environmental conditions of over 600 individuals and across three sites (2016–2019). Optimal growth rates for blades and stipes (∼13–14 cm/day) occurred within a narrow range of local environmental conditions. Growth decreased at temperatures > 10 °C, below 1 µm/L nitrate concentration, and surface light availability reduced blade growth at low and high levels (daily light integral or DLI <20 and >40 mol/m2/day). Spatiotemporal variability in these environmental drivers co-occurred with differences in growth rates, suggesting that local conditions strongly influenced growth. In particular, temperature and nutrients were un-coupled seasonally in this region, with more variable responses in growth over the primary growing season (May to September). Overall, the sensitivity of the growth rates of this annual kelp to changing climatic conditions suggests that it is a useful bioindicator for management and marine planning efforts (e.g., restoration and aquaculture) across its species range and provides a feasible metric for monitoring.
    • OPEN ACCESS
      Bigmouth Buffalo (Ictiobus cyprinellus) migratory behaviour and seasonal home range overlap are functions of geographic space in a fragmented riverscape
      FACETS • Vol. 9 • pp. 1 - 17
      In temperate rivers, where environmental conditions vary seasonally, many fishes migrate among summer, spawning, and winter habitats. Dams disrupt these migrations, limiting access to habitat and potentially affecting populations. Bigmouth Buffalo (Ictiobus cyprinellus) is a species of fish with at-risk populations in central Canada. The impact of dams on the extent of Bigmouth Buffalo migration and the overlap between summer and winter home ranges is unknown. Here, we assessed the migratory history of 80 Bigmouth Buffalo tagged with acoustic transmitters in the Red River (USA and Canada), a large binational waterway regulated by semi-passable dams. We sought to understand when and why Bigmouth Buffalo migrate, and how river use varies seasonally. Following more than 6 years of data collection, we found that the degree and probability of overlap between winter and summer home ranges varied by river section between barriers. Importantly, overlap was lowest in the longest continuous river section where well-defined migratory behaviours were observed. The results of this study reveal previously unknown details about Bigmouth Buffalo migration, demonstrate the consequences of river fragmentation on geographic space use, and highlight the importance of river connectivity to fish migration.
    • OPEN ACCESS
      Marine ecozones represent a major gap in Canadian DNA barcoding efforts
      FACETS • Vol. 9 • pp. 1 - 11
      Because of Canada’s large size, it is impractical to obtain a comprehensive perspective on biotic change through morphological approaches. DNA metabarcoding offers a potential path, but its application requires access to a well-parameterized DNA barcode reference library. This study presents the current state of DNA barcode coverage for Canadian animals, highlighting progress, identifying gaps, and providing recommendations for future research. Our analysis indicates that many of the known species (100 000 terrestrial and 6000 marine) in the Canadian fauna possess DNA barcode coverage, but there are important gaps geographically and taxonomically. We summarize DNA barcode coverage for the species in freshwater, marine, and terrestrial environments by ecoregion, finding that 95.6% of the 2.3 million Canadian barcode records derive from terrestrial ecosystems. Although the density of barcode records per 100 km² is 13x higher for terrestrial than aquatic environments (22.4 vs. 1.7), coverage for 58% of marine species is available (54% for annelids, 52% for arthropods, 88% for chordates, 39% for echinoderms, and 46% for molluscs). By revealing data-deficient areas and taxonomic groups, this study offers a roadmap for expanding the DNA barcode library for the Canadian fauna as an essential foundation for the scalable biosurveillance initiatives that inform biodiversity conservation efforts.
    • OPEN ACCESS
      A One Health perspective on recreational fisheries
      FACETS • Vol. 9 • pp. 1 - 9
      Recreational fisheries involve an intimate connection between people, individual fish, and the environment. Recreational fishers and their health crucially depend on healthy fish and ecosystems. Similarly, fish and ecosystems can be impacted by the activities of people including recreational fishers. Thus, amplified by the global interest in recreational fishing, we posit that recreational fishing is particularly suited as an empirical system to explore a One Health perspective, with a goal of creating pathways to better manage such socio-ecological systems for the benefit of people, fish, and the environment. Although zoonoses are uncommon in fishes, fish can carry pathogens, biotoxins, or contaminants that are harmful to people. When captured and released, fish can experience stress and injuries that may promote pathogen development. Similarly, when humans contribute to environmental degradation, not only are fish impacted but so are the humans that depend on them for nutrition, livelihoods, culture, and well-being. Failure to embrace the One Health perspective for recreational fisheries has the potential to negatively impact the health of fish, fisheries, people, society, and the aquatic environment—especially important since these complex social–ecological systems are undergoing rapid change.
    • OPEN ACCESS
      The many pathways of climate change affecting coastal ecosystems: a case study of western Vancouver Island, Canada
      FACETS • Vol. 10 • pp. 1 - 18
      Climate change threatens marine ecosystems with known effects on marine life, including changes in metabolic rates, survival, and community structure. Based on a structured literature review, we developed a conceptual “pathways of effects” model that summarizes how three stressors associated with climate change (warming, acidification, and storms) affect functional species groups on the West Coast of Vancouver Island, Canada. We identified 155 distinct pathways from the three stressors through 12 categories of biological effects ranging from changes in the biochemistry of individual organisms to effects on community composition. Most species groups were affected by several climate stressors and via many pathways, although individual studies generally considered only a small fraction of relevant pathways. These effects depended on the species of interest and geographical location, highlighting the importance of local research. Climate change stressors exert complex, sometimes contradictory effects that vary across ecological scales. For example, some stressors that adversely affected a species in laboratory studies appeared beneficial in community-scale field studies. Pathways of effects models are helpful tools to summarize scientific studies across ecological scales. Compiling them in standardized databases would allow researchers and practitioners to search across species and regions to better support ecosystem-based management and environmental impact assessment.
    • OPEN ACCESS
      Drivers of high rates of carbon burial in a riverine-influenced freshwater marsh in the Long Point Walsingham Priority Place of southern Ontario
      FACETS • Vol. 10 • pp. 1 - 14
      Reported rates of soil organic carbon (SOC) accumulation in wetlands are markedly higher over recent versus longer timescales, caused by SOC losses through decomposition, paleoenvironmental changes, and recent increases in sedimentation or biomass production. Explaining changes in SOC sequestration rates and determining the time horizon over which high rates are sustained are both critical for accurately measuring the potential for wetland conservation as a natural climate solution. Here, we present analyses on a 4-m core from a riverine-influenced marsh in Big Creek watershed, southern Ontario, to track changes in SOC accumulation regimes. Since wetland initiation ∼5700 years ago, mean long-term (pre-industrial) rates of SOC accumulation were 24 g C m−2 year−1, and recent rates up to four times higher. We demonstrate that elevated recent rates of SOC accumulation are largely explained by more labile carbon in surficial soils, and are sustained for less than a century before transitioning to slower burial rates of predominantly recalcitrant organic matter. However, there are exceptions to this trend, such as when labile SOC was buried intermittently during Holocene Lake Erie highstands. Our research underscores the importance of organic matter type and hydroclimatic context in predicting long-term potential for marsh soils to stabilize atmospheric carbon.
    • OPEN ACCESS
      The decline of walleye populations: an ecological tipping point?
      FACETS • Vol. 10 • pp. 1 - 17
      Walleye/ogaa (Sander vitreus (Mitchill)) (hereafter, walleye; ogaa = Ojibwe translation) populations have historically supported important multi-use, harvest-oriented fisheries. Despite intensive management, walleye populations have declined in the midwestern United States raising concerns about the sustainability of the species. Numerous factors have been implicated in walleye population declines, including climate change, habitat loss, invasive species, species-interactions, production overharvest (i.e., harvest consistently exceeding annual production), and changing angler behaviors. These factors have negatively influenced natural recruitment and contributed to depensatory recruitment dynamics. I provide a review and perspective suggesting that the current trajectory of walleye populations is at or nearing an ecological tipping point. Although fish populations are often considered compensatory (i.e., negatively density-dependent), current walleye populations appear prone to depensation (i.e., positive density dependence). My review and perspective suggest that a compensatory management perspective for walleye is misaligned. A change in management towards a depensatory resource focus using ecosystem-based fisheries management and the recognition of walleye fisheries as social–ecological systems is needed for conservation. If compensatory management ensues, walleye persistence will likely be further threatened because many drivers of change are outside of managerial control, and those commonly used within managerial control have seemingly been ineffective for sustaining or rehabilitating naturally reproducing walleye populations.
    • OPEN ACCESS
      Protection of seabed sediments in Canada's marine conservation network for potential climate change mitigation co-benefit
      FACETS • Vol. 10 • pp. 1 - 14
      Marine conserved areas (MCAs) can provide a range of ecological and socio-economic benefits, including climate change mitigation from the protection and enhancement of natural carbon storage. Canada's MCA network is expanding to encompass 30% of its Exclusive Economic Zone by 2030. At present, the network aims to integrate climate change mitigation by protecting coastal vegetated blue carbon ecosystems (saltmarsh, seagrass, kelp). Here, we argue that incorporating unvegetated seabed sediments could bring similar benefits. Seabed sediments can store and/or accumulate high densities of organic carbon, and due to their large spatial extent, contain carbon stores orders of magnitude larger than coastal vegetated habitats. We estimate that currently designated MCAs encompass only 10.8% of Canada's seabed sediment organic carbon stocks on the continental margin, and only 13.4% of areas with high carbon densities. Proposed MCAs would cover an additional 8.8% and 6.1% of total stocks and high carbon areas, respectively. We identify an additional set of high-priority seabed areas for future research and potential protection, ranking their importance based on carbon stocks, proxies for lability, and ecological/biological significance. The incorporation of seabed sediments into MCA networks could support climate change mitigation by preventing future releases of stored carbon.
    • OPEN ACCESS
      Evaluation of a decade of management of a North American aquatic invasive species (Nitellopsis obtusa) highlights scale-dependent effectiveness and monitoring gaps
      FACETS • Vol. 10 • pp. 1 - 14
      Nitellopsis obtusa (starry stonewort) is an invasive macroalga subject to substantial control efforts in the Midwestern United States; however, there has not been systematic evaluation of treatment effectiveness. We synthesized management approaches and outcomes using monitoring performed over a decade-long period across 38 lakes in Indiana, Wisconsin, and Minnesota. Copper-based algaecide treatments were the primary means of control, followed by physical removal methods or combination treatments. Control efforts and associated monitoring data varied by spatial scale, as did surveyors’ N. obtusa sampling methods. At the largest (whole-lake) scale, we found no evidence that algaecide treatments were slowing expansion or reducing abundance of N. obtusa within infested lakes. At smaller, within-lake scales, we found that algaecide and physical treatments could reduce N. obtusa frequency and biomass, but outcomes were highly variable. At the smallest scales, hand pulling was an effective containment strategy for small, localized populations that were detected early. These results highlight the need to set realistic goals for N. obtusa control and develop improved management techniques. There were also critical gaps in monitoring that limited our ability to evaluate treatment effectiveness. In particular, increased monitoring of unmanaged reference lakes and untreated areas within managed lakes is needed.
    • OPEN ACCESS
      Inuit uses of weather, water, ice, and climate indicators to assess travel safety in Arctic Canada, Alaska, and Greenland: a scoping review
      FACETS • Vol. 10 • pp. 1 - 25
      Environmental indicators are naturally occurring variables, conditions, and events that are used to assess and monitor environmental conditions and change. Inuit throughout Inuit Nunaat (Inuit circumpolar homelands) observe and experience environmental indicators as they travel year-round for harvesting and other cultural practices. Inuit draw on their observations of current conditions and their knowledge of weather, water, ice, and climate (WWIC) indicators, when seeking to predict and understand conditions that impact safe travel. This scoping review documents the types and diversity of WWIC indicators articulated in peer-reviewed and grey literature as being used by Inuit in Canada, Alaska, and Greenland to assess travel safety. Two reviewers independently screened 512 studies using pre-determined eligibility criteria and 123 studies were included for review. A total of 163 unique WWIC indicators were used across 85 communities in Canada, Alaska, and Greenland. Indicators reflect a broad range of ways that Inuit experience their environment, through sight, feel, and sound. Indicators can be considered as causal, conditional, or predictive (or a combination thereof), where knowledge of the interactions among various indicators is especially important to support safe travel. Identified gaps and future research directions included assessing key indicators to better target development of locally relevant research and information services.
    • OPEN ACCESS
      Investigating the potential uptake of microplastic-derived carbon into a boreal lake food web using carbon-13 labelled plastic
      FACETS • Vol. 10 • pp. 1 - 9
      Microplastics degrade slowly over time, leaching carbon (C) that could be subsequently incorporated into aquatic food webs. Current estimates of microplastic degradation vary, and little is known about microplastic-derived C fate under natural environmental conditions. To investigate whether microplastics leach C that is subsequently incorporated into aquatic food webs, we added isotopically enriched microplastics to Lake 378 at the Experimental Lakes Area in Ontario, Canada. In an ∼1100 L limnocorral (in situ open-bottom enclosure), we added 99% 13C-labelled polystyrene (8–216 µm in longest dimension) at a nominal concentration of 3268 particles/L. A second limnocorral without microplastics served as a negative control. Monthly measurements of δ13C-DIC and δ13C-DOC in filtered water revealed no detectable leaching of 13C from the plastic. Compound-specific isotope analysis of δ13C in amino acids of bulk plankton and periphyton revealed a slight (0.5‰) enrichment in 13C, within the range of natural variability for these organisms. Under the natural conditions of temperate oligotrophic lakes, degradation of microplastics is likely a very slow process that was not possible to detect in this 4-month experiment. Future studies should focus on assessing degradation of microplastics under realistic field scenarios to improve estimates of degradation pathways and associated time scales.
    • OPEN ACCESS
      Data and knowledge needs for improving science and policy for peatlands in Canada in a changing world: insights from Global Peatlands Initiative Workshop, June 2023
      FACETS • Vol. 10 • pp. 1 - 19
      Knowledge and data on the current function, future threats, and benefits of peatlands in Canada are required to support evidence-based decision-making to ensure they continue to provide critical ecosystem services. This is particularly relevant for Canada, given the large expanse of relatively intact peatland area. There is a need, not only to standardize protocols, but also to prioritize types of information and knowledge that can best meet conservation and management goals. This was the challenge posed to the participants of the Global Peatlands Initiative workshop in June 2023 in Quebec City, Quebec, Canada. Participants were composed of researchers using primarily Western science approaches that use peatland data for carbon accounting, policy or sustainable land use, reclamation/restoration, conservation, wildlife, and water resources applications. For seven peatland data categories (hydrometeorological and environmental sensing; peat coring and depth; greenhouse gas monitoring; biodiversity; vegetation, woody debris, and litter; Traditional Knowledge; water quality), three priority measurements were identified and recommendations for their collection were discussed. The key recommendations from the workshop were to (1) create standardized, yet flexible protocols; (2) coordinate field data collection where possible; (3) weave more Traditional Knowledge into understanding of peatlands; (4) create an atlas of existing peatland information; (5) scope opportunities to create a network of peatland “super sites”.