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'Natural' disasters (also known as geophysical disasters) involve physical processes that have a direct or indirect impact on humans. These events occur rapidly and may have severe consequences for resident flora and fauna as their habitat undergoes dramatic and sudden change. Although most studies have focused on the impact of natural disasters on humans and terrestrial systems, geophysical disasters can also impact aquatic ecosystems. Here, we provide a synthesis on the effects of the most common and destructive geophysical disasters on aquatic systems (life and habitat). Our approach spanned realms (i.e., freshwater, estuarine, and marine) and taxa (i.e., plants, vertebrates, invertebrates, and microbes) and included floods, droughts, wildfires, hurricanes/cyclones/typhoons, tornadoes, dust storms, ice storms, avalanches (snow), landslides, volcanic eruptions, earthquakes (including limnic eruptions), tsunamis, and cosmic events. Many geophysical disasters have dramatic effects on aquatic systems. The evidence base is somewhat limited for some natural disasters because transient events (e.g., tornadoes and floods) are difficult to study. Most natural disaster studies focus on geology/geomorphology and hazard assessment for humans and infrastructure. However, the destruction of aquatic systems can impact humans indirectly through loss of food security, cultural services, or livelihoods. Many geophysical disasters interact in complex ways (e.g., wildfires often lead to landslides and flooding) and can be magnified or otherwise mediated by human activities. Our synthesis reveals that geophysical events influence aquatic ecosystems, often in negative ways, yet systems can be resilient provided that effects are not compounded by anthropogenic stressors. It is difficult to predict or prevent geophysical disasters but understanding how aquatic ecosystems are influenced by geophysical events is important given the inherent connection between peoples and aquatic ecosystems. Key words: Geophysical disasters, natural disasters, natural hazards, aquatic ecosystems, ecosystem services, threats, Introduction 'Natural' disasters can be defined as 'some rapid, instantaneous or profound impact of the natural environment upon the socioeconomic system' (Alexander 2018) usually with a restricted temporal and spatial [...]

Little is known about the current state of freshwater biodiversity in Canada, one of the countries with the greatest amount of surface waters in the world. To address this knowledge gap, we compiled a list of all available assessments of conservation status for freshwater species (over 3000 taxa) and further evaluated the overall status of six distinct taxonomic groups, focusing on organisms reliant on fresh waters (i.e., aquatic plants, invertebrates (with a focus on freshwater mussels), fishes, herpetofauna (reptiles and amphibians), birds, and mammals). Overall, 11.7% of all freshwater species of plants and animals assessed were found to be 'at risk' (i.e., listed as 'Threatened', 'Endangered', or 'Extirpated') and 17.9% identified as 'Special Concern'. We found that 37.9% of species lacked sufficient data to enable their status to be assessed. Data gaps in Canada's assessment of its freshwater species were most prevalent in invertebrates (excluding freshwater mussels). Given the alarming state of freshwater biodiversity in Canada, we conclude by providing recommendations that focus on evaluating temporal trends and informing conservation actions. Les connaissances sur l'etat actuel de la biodiversite des especes d'eau douce au Canada, un des pays disposant de la plus grande quantite d'eau de surface au monde, sont limitees. Pour examiner cette lacune, nous avons compile une liste de toutes les evaluations disponibles du statut de conservation d'especes d'eau douce (plus de 3000 taxons) et evalue en outre le statut global de six groupes taxonomiques distincts, en mettant l'accent sur les organismes dependant des eaux douces (c.-a-d., les plantes aquatiques, les invertebres (plus particulierement les mulettes), les poissons, l'herpetofaune (reptiles et amphibiens), les oiseaux et les mammiferes). Globalement, 11,7 % de toutes les especes d'eau douce de plantes et d'animaux evaluees sont << en peril >> (c.-a-d., designees << menacees >>, << en voie de disparition >> ou << disparue au pays >>) et 17,9 % ont un statut de conservation << preoccupant >>. Nous constatons que les donnees disponibles sont insuffisantes pour permettre l'evaluation du statut de 37,9 % des especes. Le groupe des invertebres (a l'exception des mulettes) est celui pour lequel la prevalence des cas de manque de donnees pour l'evaluation d'especes d'eau douce au Canada est la plus grande. Au vu de l'etat alarmant de la biodiversite des especes d'eau douce au Canada, nous concluons en formulant des recommandations qui mettent l'accent sur l'evaluation des tendances dans le temps et la production de donnees pour eclairer les mesures de conservation. [Traduit par la Redaction], 1.0. Introduction Despite occupying less than 1% of the Earth's surface, the freshwater biome is home to 12% of all described species, including as much as one third of all [...]

Statistical stream temperature models predicting the fine-scale spatial distribution of water temperatures (i.e., "thermalscape") can guide aquatic species recovery and habitat restoration efforts. However, stream temperature modelling is complicated by spatial autocorrelation arising from non-independence of sampling sites within dendritic networks. We used August mean temperature data from miniature sensors deployed in Canadian Rocky Mountain streams to demonstrate two statistical stream temperature modelling techniques that account for spatial autocorrelation. The first was a spatial steam network (SSN) model specifically developed to account for spatial autocorrelation in dendritic stream networks. The second was an integrated nested Laplace approximation (INLA) model that accounts for spatial autocorrelation but was not designed to address anisotropic stream network data. We evaluated the best-fitting SSN and INLA models using leave-one-out cross-validation. Relative to INLA, SSN models had lower RMSE (1.23 vs. 1.45 C) and higher r2 (0.71 vs. 0.61); however, the SSN models required more preprocessing steps before incorporating spatially correlated random errors. We provide practical advice, an open-access r-script, and data to help non-experts develop statistical stream temperature models. [ABSTRACT FROM AUTHOR]

A fundamental consideration in aquatic invasive species risk management is the distribution of invasive taxa relative to the risk assessment area. However, sampling the distribution of aquatic invasive species (AIS) is costly and time consuming, especially when they are rare or clustered. While random sampling removes bias in most estimates, it could lead to many zeroes in the response variable if the target species is not evenly distributed. We surveyed the distribution of Tubifex tubifex, the obligate secondary host of Myxobolus cerebralis, an invasive parasite that causes whirling disease in salmonids. We used intensive grid and random sampling in a lake and two river systems but collected many samples with zero T. tubifex. Zeroaltered models identified a single source of zero T. tubifex counts in each dataset and improved model validation compared to Poisson or negative binomial models. While T. tubifex counts were not predictable using the covariates we measured, the binomial processes identified zero odds of a T. tubifex occurrence at lake sites with water depths > 2 m and stream sites with channel slopes > 3%. These covariates could be used to stratify the landscape for future sampling, which would save survey time and resources and likely reduce uncertainty in parameter estimates. Model-based sample stratification could address some of the challenges with AIS surveys when species are at low abundance or are clustered. [ABSTRACT FROM AUTHOR]

Estimating the timing and magnitude of fish movements relative to environmental factors can provide insight into why fishes behave as they do. To make broad-level inferences about fish movement in lotic environments, we conducted random-effects meta-analyses on the effects of river flow magnitude on (i) non-migratory movements, (ii) upstream migratory movements, (iii) downstream migratory movements, and (iv) fine-scale activity. We found a significant positive effect of river discharge on non-migratory movements ([bar.r] = 0.41 (mean) [+ or -] 0.07 (SE), Z = 6.06, p < 0.01, k (sample size) = 27); fishes made larger and (or) more frequent movements during periods of elevated discharge. Furthermore, non-salmonids were more affected by river flow than salmonids. River discharge also had a significant positive effect on the rate, frequency, and probability of upstream migratory movements ([bar.r] = 0.23 [+ or -] 0.10, Z = 2.24, p < 0.05, k = 8). However, the effect of discharge on the rate of downstream migratory movements ([bar.r] = -0.05 [+ or -] 0.15, Z = -0.35, p > 0.05, k = 5) and fine-scale activity ([bar.r] = 0.01 [+ or -] 0.11, Z = 0.08, p > 0.05, k = 5) were not significant. Heterogeneity of effect sizes was evident in all meta-analyses as well as inclusion and (or) publication bias. Collectively, our meta-analyses suggested that changes to a river's flow regime can modulate non-migratory fish behaviour, the consequences of which need to be explored in terms of habitat use and energy budgets. However, more studies are needed to examine potential effect modifiers and improve sample sizes overall. Key words: river, flow regime, hydropower, telemetry, swimming activity, fish movement. L'estimation de la chronologie et de l'ordre de grandeur des mouvements des poissons en relation avec les facteurs du milieu fournissent des indices pour comprendre comment les poissons agissent comme ils le font. Afin d'etablir des inferences a larges echelles a propos du mouvement des poissons dans des milieux lotiques, les auteurs ont conduit des metaanalyses a effets aleatoires concernant les effets de l'ampleur du flux des rivieres sur (i) les mouvements non-migratoires, (ii) les mouvements migratoires vers l'amont, (iii) les mouvements migratoires vers l'aval et (iv) l'activite a echelle fine. Ils ont constate un effet positif de la decharge des rivieres sur les mouvements non migratoires ([barra.r] = 0,41 (moyenne) [+ o -] 0,07 (SE), Z = 6,06, p < 0,01, k (dimension de l'echantillon) = 27); les poissons ont effectue des deplacements plus importants et plus frequents lors de periodes de decharge plus abondantes. De plus, les non-salmonides etaient plus affectes que les salmonides. La decharge des rivieres exerce aussi un effet positif significatif sur le taux/frequence/probabilite des mouvements migratoires en amont ([barra.r] = 0,23 [+ o -] 0,10, Z = 2,24, p < 0,05, k = 8). Cependant, l'effet de la decharge sur les taux de migration vers l'aval ([barra.r] = -0,05 [+ o -] 0,15, Z = -0,35, p > 0,05, k = 5) et sur l'activite a echelle fine ([barra.r] = 0,01 [+ o -] 0,11, Z = 0,08, p > 0,05, k = 5) n'etait pas significatif. L'heterogeneite des dimensions des effets etait evidente dans toutes les metaanalyses incluant les biais des inclusions/publications. Collectivement, les metaanalyses des auteurs suggerent que les changements de regime de flux d' une riviere peuvent moduler le comportement non migratoire des poissons, dont on doit explorer les consequences en terme d'utilisation de l'habitat et de budgets energetiques. Cependant, on doit conduire d'autres etudes pour examiner l' effet des modificateurs potentiels et ameliorer les dimensions des echantillons en general. Mofs-cles : riviere, regime de flux, pouvoir hydroelectrique, telemetrie, activite natatoire, mouvement des poissons., Introduction There is growing recognition that alterations to river flow regimes threaten the biodiversity and ecosystem functions of rivers on a global scale (Nilsson et al. 2005). Transportation, water supply, [...]

Educators understand that teachers' beliefs about learning, their knowledge of content, and their vision of sound instructional practices make a difference in what students learn and are able to demonstrate. A learner-centered focus using award-winning literature expands teacher knowledge of the literature and provides insight to both reading and writing not available from pre-packaged reading programs or norm-referenced tests., A learner-centered focus in reading creates a dialogue between students and teachers. This focus in classrooms can heighten awareness of the needs of individual readers, providing the impetus for teacher [...]

The intentional introduction of native cold‐water trout into high‐elevation fishless lakes has been considered a tool to build resilience to climate change (i.e., assisted colonization); however, ecological impacts on recipient communities are understudied. The purpose of this study was to inform native cold‐water trout recovery managers by assessing potential consequences of translocating a regionally native trout (westslope cutthroat trout; Oncorhynchus clarkii lewisi) into fishless mountain lakes. This study compared littoral benthic invertebrate richness, diversity, community structure and abundance between three groups of lakes (fishless, native trout, nonnative trout) in the Canadian Rocky Mountains. While richness and diversity were preserved across all lake groups, other lines of evidence suggested that the introduction of native westslope cutthroat trout into fishless lakes can alter littoral benthic invertebrate communities in similar ways as nonnative brook trout (Salvelinus fontinalis). The community structure of cutthroat trout lakes resembled brook trout lakes compared to that of fishless lakes. For example, both trout‐lake groups contained a lower density of free‐swimming ameletid mayflies and a higher density of certain burrowing taxa. Risk assessments for trout‐recovery actions should consider the potential for collateral damage to recipient invertebrate communities. Future research should identify possible cascading trophic effects on species subsidized by invertebrate prey. [ABSTRACT FROM AUTHOR]

Freshwater biodiversity is in a state of crisis. The recent development of a global emergency recovery plan to "bend the curve" for freshwater biodiversity lacks the necessary details for implementation in a regional context. Using Canada as an example, we describe a toolbox intended to equip decision-makers and practitioners with evidence-based tools for addressing threats to freshwater biodiversity. The toolbox includes two rubric-based scoring tools to inform users about the level of the reliability (e.g., transparent methods, critical appraisal) and relevancy to Canadian freshwater systems (e.g., habitat, species) of an evidence synthesis. Those scoring tools were applied to 259 evidence syntheses, also included in the toolbox, across fifty freshwater management actions. Habitat Creation, Invasive Species Removal, and Revegetation were found to have reliable evidence syntheses but there remain several actions for which the syntheses are not robust and where the evidence base is unreliable. We suggest the need for more rigorously conducted empirical tests of freshwater management actions, further evidence synthesis, and clearer conveyance of implications for decision-makers and practitioners. Decision-makers and practitioners should use the two scoring tools on syntheses outside this project and tailor them to their regions. Given the global interest in addressing the freshwater biodiversity crisis and the necessity to engage and empower decision-makers and practitioners on a regional basis, we anticipate this toolbox will serve as a model for regions beyond Canada. Future studies to understand if and how the toolbox is used will be needed to make refinements and ensure it benefits freshwater biodiversity. • Current management of freshwater ecosystems fails to address the global freshwater biodiversity crisis • Evidence syntheses and reviews are a valuable resource to decision-makers and practitioners for informing conservation actions • The toolbox consists of over 250 freshwater management evidence syntheses, scored based on the included appraisal tools • Syntheses demonstrate a poor systematic review conduct but show a strong potential for regional relevance and applicability [ABSTRACT FROM AUTHOR]