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- OPEN ACCESS
Thermal sensitivity and flow-mediated migratory delays drive climate risk for coastal sockeye salmon
- William I. Atlas,
- Karl M. Seitz,
- Jeremy W.N. Jorgenson,
- Ben Millard-Martin,
- William G. Housty,
- Daniel Ramos-Espinoza,
- Nicholas J. Burnett,
- Mike Reid, and
- Jonathan W. Moore
Climate change is subjecting aquatic species to increasing temperatures and shifting hydrologic conditions. Understanding how these changes affect individual survival can help guide conservation and management actions. Anadromous Pacific salmon (Oncorhynchus spp.) in some large river systems are acutely impacted by the river temperatures and flows encountered during their spawning migrations. However, comparatively little is known about drivers of en route mortality for salmon in smaller coastal watersheds, and climate impacts may differ across watersheds and locally adapted salmon populations. To understand the effects of climate on the survival of coastal sockeye salmon (Oncorhynchus nerka; hísn in Haíɫzaqv), we tagged 1785 individual fish with passive integrated transponders across four migration seasons in the Koeye River—a low-elevation watershed in coastal British Columbia—and tracked them during their relatively short migration (∼13 km) from river entry to spawning grounds. Overall, 64.7% of sockeye survived to enter the spawning grounds, and survival decreased rapidly when water temperatures exceeded 15 °C. The best-fitting model included an interaction between river flow and temperature, such that temperature effects were worse when flows were low, and river entry ceased at the lowest flows. Results revealed temperature-mediated mortality and migration delays from low water that may synergistically reduce survival among sockeye salmon returning to coastal watersheds. - OPEN ACCESSPacific sand lance (Ammodytes personatus) and surf smelt (Hypomesus pretiosus) are ecologically important forage fish in the marine food webs within the Salish Sea, including British Columbia (BC). Although important, little information exists around the spatiotemporal distribution of these fishes’ beach spawning habitat in the BC Salish Sea. In 2017, the Mount Arrowsmith Biosphere Region Research Institute initiated spawning beach surveys within the Mount Arrowsmith Biosphere Region (MABR). Surveys have geographically expanded along the eastern Vancouver Island coastline between Bowser and Cowichan Bay, BC, including Gabriola Island and Thetis Island. Pacific sand lance embryos have been detected at 17 beaches, with six beaches located within the MABR. Pacific sand lance spawning events have been detected between November and mid-February, with the bulk of embryos detected in November and December. To date, surf smelt embryos have not been detected at the 56 different beaches. These data begin to fill existing data gaps surrounding Pacific sand lance and surf smelt in BC. Furthermore, longer-term data submissions to the Strait of Georgia Data Centre, an open-access database, will provide the necessary data needed to advocate for improved regulatory protections for these ecologically important fish and their spawning habitat.
- OPEN ACCESS
- Bryant C. DeRoy,
- Vernon Brown,
- Christina N. Service,
- Martin Leclerc,
- Christopher Bone,
- Iain McKechnie, and
- Chris T. Darimont
Environmental management and monitoring must reconcile social and cultural objectives with biodiversity stewardship to overcome political barriers to conservation. Suitability modelling offers a powerful tool for such “biocultural” approaches, but examples remain rare. Led by the Stewardship Authority of the Kitasoo/Xai’xais First Nation in coastal British Columbia, Canada, we developed a locally informed suitability model for a key biocultural indicator, culturally modified trees (CMTs). CMTs are trees bearing evidence of past cultural use that are valued as tangible markers of Indigenous heritage and protected under provincial law. Using a spatial multi-criteria evaluation framework to predict CMT suitability, we developed two cultural predictor variables informed by Kitasoo/Xai’xais cultural expertise and ethnographic data in addition to six biophysical variables derived from LiDAR and photo interpretation data. Both cultural predictor variables were highly influential in our model, revealing that proximity to known habitation sites and accessibility to harvesters (by canoe and foot) more strongly influenced suitability for CMTs compared with site-level conditions. Applying our model to commercial forestry governance, we found that high CMT suitability areas are 51% greater inside the timber harvesting land base than outside. This work highlights how locally led suitability modelling can improve the social and evidentiary dimensions of environmental management. - OPEN ACCESSMicroplastics are globally ubiquitous contaminants, but quantitative data on their presence in freshwater environments are sparse. This study investigates the occurrence, composition, and spatial trends of microplastic contamination in the North Saskatchewan River flowing through Edmonton, Alberta, the fifth largest city in Canada. Surface water samples were collected from seven sites throughout the city, upstream and downstream of the city, and near potential point sources (i.e., a wastewater treatment plant). Samples were spiked with fluorescent microbeads as internal standards and extracted by wet peroxide oxidation and density floatation. Microplastics were found in all samples, ranging in concentration from 4.6 to 88.3 particles·m−3 (mean = 26.2 ± 18.4 particles·m−3). Fibers were the dominant morphology recovered, and most were of anthropogenic origin and chemically identified as dyed cotton or polyester by Raman microspectroscopy. The majority of fragments were identified as polyethylene or polypropylene. No upstream to downstream differences were found in concentration, size distribution, or morphological composition suggesting nonpoint sources of microplastics to the river. This study represents one of the first investigations into the occurrence of microplastics in the freshwater environment in western Canada and will provide a baseline for future studies.
- OPEN ACCESSRoad salt runoff is a leading cause of secondary freshwater salinization in north temperate climates. Increased chloride concentrations in freshwater can be toxic and lead to changes in organismal behavior, lethality, biotic homogenization, and altered food webs. High chloride concentrations have been reported for winter months in urban centers, as road density is highest in cities. However, summer chloride conditions are not typically studied as road salt is not actively applied outside of winter months, yet summer is when many taxa reproduce and are most sensitive to chloride. In our study, we test the spatial variability of summer chloride conditions across four watersheds in Toronto, Canada. We find 89% of 214 sampled sites exceeded the federal chronic exposure guidelines for chloride, and 13% exceeded the federal acute guidelines. Through a model linking concentration to cumulative proportion of impacted species, we estimate 34% of sites show in excess of one-quarter of all species may be impacted by their site-specific chloride concentrations, with up to two-thirds of species impacted at some sites. Our results suggest that even presumed low seasons for chloride show concentrations sufficient to cause significant negative impacts to aquatic communities.
- OPEN ACCESS
- Jade R. Steel,
- William I. Atlas,
- Natalie C. Ban,
- Kyle Wilson,
- Jayda Wilson,
- William G. Housty, and
- Jonathan W. Moore
Wild salmon are central to food security, cultural identity, and livelihoods of coastal Indigenous communities. Yet ongoing inequities in governance, declining fish populations, and mixed-stock ocean fisheries may pose challenges for equitable access between Indigenous fishers and other non-Indigenous fishers. We sought to understand current perceptions among Haíłzaqv (Heiltsuk) fishers towards salmon fisheries and their management. We conducted dockside surveys with both Haíłzaqv fishers and sport fishers, and in-depth interviews with Haíłzaqv fishers, community members, and natural resource managers. From these surveys and interviews we quantified satisfaction among both food, social, and ceremonial fishers and visiting recreational fishers with the current salmon fishery and associated social-ecological drivers, and characterized perceptions among Haíłzaqv people of salmon fisheries and management. Second, we synthesized community perceptions of the revitalization of terminal, communally run salmon fisheries within Haíłzaqv territory as a tool for their future salmon management. Finally, we elicited information from Haíłzaqv fishers about the barriers people in their community currently face in accessing salmon fisheries. Our findings suggest that low salmon abundance, increased fishing competition, and high costs associated with participation in marine mixed-stock fisheries currently hinder access and equity for Haíłzaqv fishers. This community-based research can help strengthen local, Indigenous-led management of salmon into the future. - OPEN ACCESSThere have been rapid recent reductions in sea ice age and extent in the Canadian Arctic, but little previous analysis of how this has impacted the navigability of Arctic shipping. In this study we analyze how navigability changed over the period 1972–2016 by converting Canadian Ice Service ice charts to shipping navigability charts for different hull strength classifications based on the Arctic Ice Regime Shipping System. Analysis focuses on the southern route of the Northwest Passage, and the Arctic Bridge route across Hudson Bay, for changes in early-season (∼25 June), mid-season (∼3 September), and late-season (∼15 October) conditions. Results reveal that there has been a marked easing in shipping navigability for all vessels over the past decade, driven by reductions in the area and age of sea ice, particularly across the southern route of the Northwest Passage. Both medium (Type B) and little (Type E) ice strengthened vessels were able to transit the full length of this route in the middle part of the shipping season in 2012–2016, but not in 1972–1976 or 1992–1996.
- OPEN ACCESS
- Krishna Bahadur KC,
- Arthur Gill Green,
- Dan Wassmansdorf,
- Vivek Gandhi,
- Khurram Nadeem, and
- Evan D.G. Fraser
Climate change will create warmer temperatures, greater precipitation, and longer growing seasons in northern latitudes making agriculture increasingly possible in boreal regions. To assess the potential of any such expansion, this paper provides a first-order approximation of how much land could become suitable for four staple crops (corn, potato, soy, and wheat) in Canada by 2080. In addition, we estimate how the environmental trade-offs of northern agricultural expansion will impact critical ecosystem services. Primarily, we evaluate how the regulatory ecosystem services of carbon storage and sequestration and the habitat services supporting biodiversity would be traded for the provisioning services of food production. Here we show that under climate change projected by Canadian Earth System Model (CanESM2) Representative Concentration Pathway 4.5, ∼1.85 million km2 of land may become suitable for farming in Canada’s North, which, if utilized, would lead to the release of ∼15 gigatonnes of carbon if all forests and wetlands are cleared and plowed. These land-use changes would also have profound implications for Indigenous sovereignty and the governance of protected and conserved areas in Canada. These results highlight that research is urgently needed so that stakeholders can become aware of the scope of potential economic opportunities, cultural issues, and environmental trade-offs required for agricultural sustainability in Canada. - OPEN ACCESS
- Joanne L. Parrott,
- Grazina Pacepavicius,
- Kallie Shires,
- Stacey Clarence,
- Hufsa Khan,
- Madelaine Gardiner,
- Cheryl Sullivan, and
- Mehran Alaee
Metformin is a glucose-lowering drug taken for diabetes. It is excreted by humans in urine and detected in municipal wastewater effluents and rivers. Fathead minnows (Pimephales promelas) were exposed over a life cycle to measured concentrations of metformin: 3.0, 31, and 322 μg/L. No significant changes were observed in survival, maturation, growth, condition factor, or liver size. Relative ovary size of females exposed to 322 μg/L metformin was significantly larger than controls. There was no induction of vitellogenin in plasma of minnows, and gonad maturation was not statistically different from controls. The start of breeding was delayed by 9–10 d in the mid- and high metformin treatments (statistically significant only in the mid-concentration), but numbers and quality of eggs were not statistically different from controls. There were no effects of metformin on survival or growth of offspring. Exposure to metformin at environmentally relevant concentrations (i.e., 3.0 and 31 μg/L metformin) caused no adverse effects in fathead minnows exposed for a life cycle, with the exception of a delay in time to first breeding (that did not impact overall egg production). The results of the study are important to help understand whether metformin concentrations in rivers and lakes can harm fishes. - OPEN ACCESSThe degree to which human actions affect marine fisheries has been a fundamental question shaping people’s relationship with the sea. Today, divergences in stakeholder views about the impacts of human activities such as fishing, climate change, pollution, and resource management can hinder effective co-management and adaptation. Here, we used surveys to construct mental models of the Maine lobster fishery, identifying divergent views held by two key stakeholder groups: lobster fishers and marine scientists. The two groups were differentiated by their perceptions of the relative impact of pollution, water temperature, and fishing. Notably, many fishers perceive the process of fishing to have a positive effect on fisheries through the input of bait. Scientists exhibited a statistically significantly stronger concern for climate change and identified CO2 as one of the dominant pollutants in the Gulf of Maine. However, fishers and scientists agreed that management has a positive impact, which appeared to be a change over the past two decades, possibly due to increased collaboration between the two groups. This work contributes to the goal of decreasing the distance between stakeholder perspectives in the context of a co-managed fishery as well as understanding broader perceptions of impacts of human activities on marine ecosystems.
- OPEN ACCESSWe examined uptake of polychlorinated biphenyls (PCBs) into various marine sediment feeders relative to physical and geochemical factors and transfer to higher trophic levels. PCBs exceeding Canadian Council Ministers of the Environment Guidelines by 6–55× were found in industrialized harbours and some near-outfall sediments, indicating ongoing land input. Sediment PCBs were correlated with organic flux and content. Tissue PCBs were >10× sediment PCBs in all samples and highest in Victoria Harbour infauna, suggesting considerable uptake from these extremely contaminated, organically enriched, chronically disturbed sediments. Sediment PCBs were the primary predictor of tissue lipid PCBs followed by %fines. This results in generally higher tissue PCBs in more depositional regions. The lipid/sediment PCBs (uptake rate) declined with increasing sediment PCBs, acid volatile sulfides and benthos biomass turnover. PCB homologue composition did not change with uptake from sediments or at higher trophic levels, suggesting minimal metabolization in tissues. Trophic bio-magnification occurs since lipid PCBs were 2–100× higher in seal blubber than sediment feeders. PCBs were compared with polybrominated diphenyl ethers (PBDEs) for the same samples. PCBs were highest in industrialized harbours, whereas PBDEs were elevated in harbours but highest near wastewater discharges. This reflects differences in usage history, sediment dynamics, and affinities. PCBs appear to be more bio-accumulative and persistent at higher trophic levels than PBDEs.
- OPEN ACCESSAccurate classification of maturity status and estimation of size at 50% maturity for male crabs are important to the management of North Pacific crab stocks, which form the basis of several economically valuable fisheries. We demonstrate a straightforward maturity classification approach applied to male Tanner crabs (Chionoecetes bairdi), based on the use of log-transformed chela height distributions calculated via kernel density functions. The linear equation defining the relationship between the minima of these chela height distributions, and the midpoint of the corresponding carapace width bins is then used to estimate the incidence of maturity by size group across the population. We demonstrate the performance of this approach relative to two other currently applied methodologies. Finally, we apply this method to assess annual size at 50% maturity in eastern Bering Sea male Tanner crabs, and spatiotemporal trends in this parameter. We demonstrate the existence of high interannual and spatial variability in this population metric and find evidence of a decline in size at maturity in the western stock.
- OPEN ACCESSIn response to colonial research paradigms that have subjugated Indigenous Peoples, knowledges, lands, and waters, Indigenous research methodologies have emerged to center Indigenous visions and voices in research practice. Here, we employ such methodologies to improve collective understanding of the state and future of wild Pacific salmon (Oncorhynchus spp.) and fish–people–place relationships across British Columbia’s three largest salmon-producing rivers: the Fraser, Skeena, and Nass. Through partnerships with 18 communities of “Salmon People” and semi-structured interviews with 48 knowledge holders (i.e., Elders), we learned that, on average, Elders spent more than half of a century actively engaged in salmon fishing and processing. Modern salmon catches are reported to be approximately one-sixth of what they were estimated to be five to seven decades ago, and the top five threats to salmon identified by Elders included (i) aquaculture, (ii) climate change, (iii) contaminants, (iv) industrial development, and (v) infectious diseases. Threat priorities varied regionally, reflecting distinct lived experiences and regional variation in the prevalence and impact of different threats. Elders perceived threats to salmon equally as threats to aquatic health and human well-being, with evidence that the relationships between people and water, and salmon and people, are being profoundly transformed.
- OPEN ACCESSBetween 1962 and 1969, 10 tonnes of mercury were discharged from a chlor-alkali plant in Dryden, Ontario, to the English–Wabigoon River. Present-day fish mercury concentrations are amongst the highest recorded in Canada. In 2017, the Grassy Narrows Science Team found no evidence of ongoing discharges from the plant site to the river water, even though large quantities of mercury remain at the site. Instead, our data suggest that ongoing erosion of high mercury particles by the river, as it meanders through contaminated floodplains, is responsible for present-day transport of mercury to Clay Lake and to Ball Lake, located 154 km downstream. In Clay Lake, surface sediment total mercury concentrations and inflow water concentrations are still about 15 times above background (86 km downstream), and in Ball Lake mercury concentrations in sediments appeared to be still increasing. The remobilization of legacy inorganic mercury from riverbank erosion between Dryden and Clay Lake stimulates methyl mercury production there, in Clay Lake, and in Ball Lake. The large quantities of methyl mercury produced between Dryden and Clay Lake are mostly dissolved in water and are swept downstream, elevating concentrations in water and biota throughout the system. Several options for remediating the ongoing contamination are discussed.
- OPEN ACCESSThis paper reviews a century of Kwakwaka’wakw knowledge on ecological, climate, and social change. We trace the era of Indigenous governance (about the precolonial period), especially from about 1910 to the devastation of the flood in Dzawada’enuxw First Nation territory in Kingcome, British Columbia, in 2010. This time period has been chosen as the assessment period as this is the lifetime of the 10 Elders that we collaborated with to understand and position change during this tumultuous era. We call the results of this process “a century of knowledge”. Ecological, social, and climate change are positioned with scientific literature for potential divergence/convergence. Almost all aspects of the Kwakwaka’wakw home area have undergone large-scale changes including clear-cut forestry, salmon farms, climate change affecting species ranges, cultural impositions, and colonial processes working to destroy Indigenous governance. Despite these imposed changes, the communities emerge as survivors on their own terms, including using the traditional feast system known as the Potlatch to come to terms with the devastation of the 2010 flood and beyond.
- OPEN ACCESSEthnobiological studies on folk, common, or popular names that fishers use to identify fish can help improve fisheries monitoring and collaborations between fishers and researchers. This study investigates fishers’ knowledge (recognition, naming, and habitat use) on 115 and 119 fish species, respectively, in the Negro and Tapajos Rivers, two megadiverse rivers in the Brazilian Amazon, and investigates the relationship between such knowledge and fish importance to fisheries, fish abundance, and fish size. We also compared fishers’ perceptions on fisheries and fish abundance with literature data on fish harvests and fish sampling. We interviewed 16 fishers in 16 communities (one fisher per community, 8 communities along each river). These fishers recognized an average of 91 ± 10.4 species in the Negro River and 115 ± 7.2 species in the Tapajos River, but all fishers recognized 114 species in Negro and all species in Tapajos. The fishers’ knowledge of fish species was positively related to fishers’ perceptions on fish abundance, size, and importance to fisheries in the Negro, but only positively related to fish size in the Tapajos. Our results highlight the usefulness of fishers’ knowledge to providing data on use and cultural relevance of fish species in high diversity aquatic ecosystems.
- OPEN ACCESSWith the influence of climate change on marine systems expanding, climate adaptation will be fundamental for the future of fisheries management. An exponential increase in Atlantic halibut Hippoglossus hippoglossus landings over the past decade has coincided with warming ocean temperatures. Here, we explore how historical changes in abundance have been linked to changing thermal habitat conditions and project trends with a warming climate under different emissions scenarios. From 1990 to 2018, available thermal habitat increased by 11.6 ± 7.35% and growing degree days have increased by 13.5 ± 7.86 °C·days across the region. With warming, the probability of occurrence is projected to increase up to 20.5% in Canada by 2085 under RCP 8.5 for Atlantic halibut. Our results suggest that shifting patterns of halibut distribution and abundance are linked to thermal conditions and that continued warming will likely continue to enhance habitat conditions, leading to increased abundance in the Canadian range. Collectively, these results illustrate the influence of shifting environmental conditions on population dynamics and emphasize the importance of adaptive management practices in a dynamic future climate.
- OPEN ACCESSTrash capture devices (TCDs) are a rapidly evolving tool for municipal governments, non-governmental organizations, and industries to divert litter from our waterways. Here, we introduce protocols to initiate trash trapping projects to quantify and characterize captured anthropogenic litter based on a case study using Seabins. In addition, we have introduced a network for global data collection via TCDs. Our first protocol is a visual audit of the potential site to inform the type and location for TCD deployment. Our next two protocols quantify and characterize the litter captured by TCDs: (1) a simple protocol intended for daily monitoring and (2) a detailed protocol to characterize and quantify all large debris (>3 cm) and a subset of the small debris (2 mm–3 cm) caught in the devices. Using Seabins in the Toronto Harbour to test our methodology, we found that our subsampling methodology has a 6.9% error rate. Over a 19-week period, the Seabins captured ∼85 000 pieces of small debris. Our study highlights the utility of TCDs and proposes methods to realize this utility globally. TCDs should become more widespread and utilized as a triple threat: a cleanup tool, a data collection tool, and a platform for outreach and education.
- OPEN ACCESS
- Sachiko Ouchi,
- Lori Wilson,
- Colette C.C. Wabnitz,
- Christopher D. Golden,
- Anne H. Beaudreau,
- Tiff-Annie Kenny,
- Gerald G. Singh,
- William W.L. Cheung,
- Hing Man Chan, and
- Anne K. Salomon
Understanding mechanisms that promote social-ecological resilience can inform future adaptation strategies. Among seafood dependent communities, these can be illuminated by assessing change among fisheries portfolios. Here, in collaboration with a Coast Salish Nation in British Columbia, Canada, we used expert Indigenous knowledge and network analyses to chronicle differences in fisheries portfolios pre and post a social-ecological regime shift. We then evaluated key drivers of change using semi-structured interviews. We found that while portfolios decreased in diversity of seafood types harvested and consumed among individuals overtime, portfolios increased in their diversification at the community level because more similar seafoods within less diverse individual portfolios were more commonly harvested and consumed by the Nation as a whole. Thus, diversity can operate simultaneously in opposing directions at different scales of organization. Experts identified four key mechanisms driving these changes, including commercial activities controlled by a centralized governance regime, intergenerational knowledge loss, adaptive learning to new ecological and economic opportunities, and the trading of seafood with other Indigenous communities. Unexpectedly, increased predation by marine mammals was also flagged as a key driver of change. Adaptation strategies that support access to and governance of diverse fisheries, exchange of seafoods among communities, and knowledge transfer among generations would promote social-ecological resilience, food security, and community well-being. - OPEN ACCESS
- Jessica Garzke,
- Ian Forster,
- Sean C. Godwin,
- Brett T. Johnson,
- Martin Krkošek,
- Natalie Mahara,
- Evgeny A. Pakhomov,
- Luke A. Rogers, and
- Brian P.V. Hunt
Migrating marine taxa encounter diverse habitats that differ environmentally and in foraging conditions over a range of spatial scales. We examined body (RNA/DNA, length-weight residuals) and nutritional (fatty acid composition) condition of juvenile sockeye salmon (Oncorhynchus nerka) in British Columbia, while migrating through oceanographically variable waters. Fish were sampled in the stratified northern Strait of Georgia (NSoG); the highly mixed Johnstone Strait (JS); and the transitional zone of Queen Charlotte Strait (QCS). In 2015, body and nutritional condition were high in the NSoG but rapidly declined to reach lowest levels in JS where prey availability was low, before showing signs of compensatory growth in QCS. In 2016, juvenile salmon had significantly lower condition in the NSoG than in 2015, although zooplankton biomass was similar, condition remained low in JS, and no compensatory growth was observed in QCS. We provide evidence that differences in juvenile salmon condition between the two years were due to changes in the food quality available to juvenile fish. We propose that existing hypotheses about fish survival need to be extended to incorporate food quality in addition to quantity to understand changes in fish condition and survival between years.