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Demands for moral development are increasing in business and professional training. Mixed results of diversity training programs in the higher education sector suggest that innovative approaches are required for preparing students to become morally upright leaders and teachers. This research looks at the implementation of an online interactive tutorial that focuses on students working and learning together with others from a variety of diverse backgrounds. The study comprises a three-year investigation on the attitudes and understandings of students prior to a group work assessment task, and after completing the online tutorial. First year primary education students (n = 594) completed pre- and post-surveys on their perspective of working with others, with a moderating educational intervention. Results revealed mixed views about the value of the program to this generation of students. We make suggestions for institutions of higher education to consider when creating diversity training and support for university students.

Understanding how sublethal impacts of toxicants affect population‐relevant outcomes for organisms is challenging. We tested the hypotheses that the well‐known sublethal impacts of methylmercury (MeHg) and a polychlorinated biphenyl (PCB126) would have meaningful impacts on cohort growth and survival in yellow perch (Perca flavescens) and Atlantic killifish (Fundulus heteroclitus) populations, that inclusion of model uncertainty is important for understanding the sublethal impacts of toxicants, and that a model organism (zebrafish Danio rerio) is an appropriate substitute for ecologically relevant species (yellow perch, killifish). Our simulations showed that MeHg did not have meaningful impacts on growth or survival in a simulated environment except to increase survival and growth in low mercury exposures in yellow perch and killifish. For PCB126, the high level of exposure resulted in lower survival for killifish only. Uncertainty analyses increased the variability and lowered average survival estimates across all species and toxicants, providing a more conservative estimate of risk. We demonstrate that using a model organism instead of the species of interest does not necessarily give the same results, suggesting that using zebrafish as a surrogate for yellow perch and killifish may not be appropriate for predicting contaminant impacts on larval cohort growth and survival in ecologically relevant species. Our analysis also reinforces the notion that uncertainty analyses are necessary in any modeling assessment of the impacts of toxicants on a population because it provides a more conservative, and arguably realistic, estimate of impact. Environ Toxicol Chem 2024;43:2122–2133. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Mortality rates are major determinants of long-term sustainability of exploited fish populations, yet accurately estimating these rates can be challenging. We used simulations to evaluate nonspatial and spatial modeling approaches for estimating mortality rates from acoustic telemetry detection data. Data were generated assuming different receiver configurations (grids, lines), number of receivers, and mortality levels. Relative error rates for total mortality ranged from 0% to 83% for the nonspatial model and from 1% to 141% for the spatial model. Absolute error rates ranged from 0.00 to 0.11 for the nonspatial model and from 0.01 to 0.15 for the spatial model. Accuracy and precision in mortality estimates were sensitive to assumed mortality rates and receiver configurations; the high-density receiver grid resulted in the lowest error rates. Estimates were consistently positively biased. We recommend using grid receiver configurations for mortality rate estimation from acoustic telemetry studies. The potential for biased mortality estimation from acoustic telemetry detection data should be considered during study design, particularly for those species with behavior and ecology that may result in long periods without detection. Bien que les taux de mortalite soient d'importants determinants de la perennite a long terme des populations de poissons exploitees, l'estimation exacte de ces taux presente son lot de defis. Nous avons utilise des simulations pour evaluer des approches de modelisation non spatiale et spatiale pour estimer les taux de mortalite a partir de donnees de detection par telemetrie acoustique. Les donnees ont ete generees en presupposant differentes configurations de recepteurs (grilles, lignes), differents nombres de recepteurs et differents degres de mortalite. Les erreurs relatives sur la mortalite totale vont de 0 % a 83 % pour le modele non spatial et de 1 % a 141 % pour le modele spatial. Les erreurs absolues vont de 0,00 a 0,11 pour le modele non spatial et de 0,01 a 0,15 pour le modele spatial. L'exactitude et la precision des estimations de la mortalite sont sensibles aux taux de mortalite et a la configuration de recepteurs presumes; la grille de forte densite de recepteurs donne les erreurs les plus faibles. Les estimations presentent uniformement un biais positif. Nous recommandons d'utiliser des configurations de recepteurs en grille pour l'estimation des taux de mortalite a partir d'etudes de telemetrie acoustique. Le potentiel de biais dans les estimations de la mortalite a partir de donnees de detection par telemetrie acoustique devrait etre pris en consideration durant la conception d'etudes, particulierement pour les especes dont le comportement et l'ecologie pourraient se traduire par de longues periodes sans detection. [Traduit par la Redaction], Introduction Mortality rate is a critical population dynamics parameter for sustainable management of exploited fish populations; despite its importance, accurately estimating mortality rates remains challenging. Tagging studies in which fish [...]

Salmon populations harvested in mixed-stock fisheries can exhibit genotypic, behavioral, and life history diversity that can lead to heterogeneity in population productivity and size. Methods to quantify this heterogeneity among populations in mixed-stock fisheries are not well-established but are critical to assessing harvest-biodiversity trade-offs when setting harvest policies. We developed an integrated, age-structured, state-space model that allows for more complete use of available data and sharing of information than simpler methods. We compared a suite of state-space models of varying structural complexity to simpler regression-based approaches and, as an example case, fitted them to data from 13 Chinook salmon (Oncorhynchus tshawytscha) populations in the Kuskokwim drainage in western Alaska. We found biological and policy conclusions were largely consistent among state-space models but differed strongly from regression-based approaches. Simulation trials illustrated our state-space models were largely unbiased with respect to spawner-recruit parameters, abundance states, and derived biological reference points, whereas the regression-based approaches showed substantial bias. These findings suggest our state- space model shows promise for informing harvest policy evaluations of harvest-biodiversity trade-offs in mixed-stock salmon fisheries. Les populations de saumons exploitees dans le cadre de peches de stocks melanges peuvent presenter une diversite genotypique, comportementale et de cycles biologiques pouvant entrainer une heterogeneite sur le plan de la productivite et de la taille des populations. Si les methodes pour quantifier cette heterogeneite entre populations dans les peches de stocks melanges ne sont pas bien etablies, elles sont neanmoins essentielles pour evaluer les compromis entre les prises et la biodiversite dans l'elaboration de politiques sur les prises. Nous avons developpe un modele integre d'espace d'etats structure par age qui permet une utilisation plus exhaustive des donnees disponibles et un plus grand partage d'information que des methodes plus simples. Nous avons compare une serie de modeles d'espace d'etats de differents degres de complexite structurale a des approches plus simples reposant sur la regression et, a titre d'exemple, les avons cales sur des donnees pour 13 populations de saumons chinooks (Oncorhynchus tshawytscha) dans le bassin versant du fleuve Kuskokwim dans l'ouest de l'Alaska. Nous constatons que les conclusions concernant la biologie et les politiques concordent generalement d'un modele d'espace d'etats a l'autre, mais que ces conclusions sont tres differentes de celles tirees d'approches basees sur la regression. Des essais de simulation illustrent le fait que nos modeles d'espace d'etats ne presentent generalement pas de biais associe aux parametres des relations geniteurs-recrues, aux etats d'abondance et aux points de reference biologiques derives, alors que les approches basees sur la regression montrent un biais considerable. Ces constatations indiqueraient que notre modele d'espace d'etats est prometteur pour ce qui est d'eclairer les evaluations des compromis entre prises et biodiversite dans l'elaboration de politiques sur les prises pour les peches aux saumons de stocks melanges. [Traduit par la Redaction], Introduction Pacific salmon (Oncorhynchus spp.) populations are commonly harvested at a distance from their spawning grounds, and consequently multiple populations are co-mingled and often managed as a single stock. However, [...]

Previous research has demonstrated a large movement of hatchery-reared Chinook salmon (Oncorhynchus tshawytscha) from Lake Huron to Lake Michigan, suggesting the potential for wild fish to exhibit similar movement patterns. We assessed the feasibility of using otolith microchemistry to estimate the natal source composition of wild Chinook salmon in Lake Michigan and evaluate interbasin movement. Otolith pairs were extracted from juvenile and adult fish collected in 2015 and 2016 from Great Lakes tributaries. Otoliths were analyzed using laser ablation inductively coupled plasma mass spectrometry to determine trace element concentrations, and four multivariate classification algorithms were evaluated for classification accuracy. Juvenile data reclassified to their natal regions with up to 89% success on a basin level, with a random forest approach performing the best among all models. Assigning adults to their natal origins resulted in more success on a basin-wide scale (74% to 88%) compared with a regional scale (32% to 51%), but success was still below juvenile reclassification accuracy. Our findings suggest that otolith microchemistry can be used to estimate wild Chinook salmon interbasin movement and that classification accuracy can be improved by matching juvenile and adult year classes in our assessment samples. Ultimately, we intend to use these models to assess the effects of wild Chinook salmon interbasin movement on Lake Michigan predatory demand and evaluate the risks of various stocking alternatives. Des travaux anterieurs ont demontre un important deplacement de saumons chinooks (Oncorhynchus tshawytscha) issus d'ecloserie a partir du lac Huron vers le lac Michigan, donnant a penser que des poissons sauvages pourraient presenter des motifs de deplacement semblables. Nous avons evalue la faisabilite d'utiliser la microchimie des otolites pour estimer la composition des origines natales de saumons chinooks sauvages dans le lac Michigan et evaluer les deplacements entre bassins. Des paires d'otolites ont ete extraites de poissons juveniles et adultes preleves en 2015 et 2016 d'affluents des Grands Lacs. Les otolites ont ete analyses par spectrometrie de masse a plasma inductif jumelee a l'ablation au laser afin de determiner les concentrations d'elements traces, et quatre algorithmes de classement multivaries ont ete evalues pour determiner l'exactitude du classement en decoulant. Le succes du reclassement des juveniles dans leurs regions natales atteignait jusqu'a 89 % en ce qui concerne le bassin, l'approche par forets aleatoires donnant les meilleurs resultats de tous les modeles evalues. L'affectation d'adultes a leurs origines natales s'est averee plus probante a l'echelle du bassin (de 74 % a 88 %) qu'a l'echelle regionale (de 32 % a 51 %), mais ces taux de reussite etaient quand meme inferieurs a l'exactitude du reclassement des juveniles. Nos constatations donnent a penser que la microchimie des otolites peut etre utilisee pour estimer les deplacements entre bassins de saumons chinooks sauvages et que l'exactitude du classement peut etre amelioree en jumelant les classes d'age de juveniles et d'adultes dans les echantillons utilises pour l'evaluation. A terme, nous comptons utiliser ces modeles pour evaluer les effets des deplacements entre bassins des saumons chinooks sauvages sur la demande associee a la predation dans le lac Michigan et evaluer les risques decoulant de diverses options d'empoissonnement. [Traduit par la Redaction], Introduction Chinook salmon (Oncorhynchus tshawytscha) were introduced to the Laurentian Great Lakes in the late 1960s with intentions of establishing a sport fishery and controlling invasive alewife (Alosa pseudoharengus) (Kocik [...]

Management agencies are tasked with difficult decisions for conservation and management of natural resources. These decisions are difficult because of ecological and social uncertainties, the potential for multiple decision makers from multiple jurisdictions, and the need to account for the diverse values of stakeholders. Decision analysis provides a framework for accounting for these difficulties when making conservation and management decisions. We discuss the benefits of the application of decision analysis for these types of issues and provide insights from three case studies from the Laurentian Great Lakes. These case studies describe applications of decision analysis for decisions within an agency (management of double-crested cormorant), among agencies (response to invasive grass carp), and among agencies and stakeholders (sustainable fisheries harvest management). These case studies provide insight into the ways that decision analysis can be useful for conservation and management of natural resources, but we also highlight future needs for decision making for these resources. In particular, applications of decision analysis for conservation and management would benefit from enhanced integration of both ecological and social science, inclusion of a broader base of stakeholders and rightsholders, and better educational opportunities surrounding decision analysis for undergraduates and graduate students of natural resources management programs. Specific lessons from our experiences include the importance of establishing trust and transparency early through the formation of a working group, collaboratively defining objectives and evaluating uncertainties, risks, and tradeoffs, and implementing participatory modeling processes with an independent facilitator with appropriate quantitative skills. History: This paper has been accepted for the Decision Analysis Special Issue on Decision Analysis to Advance Environmental Sustainability. Funding: This study was supported by Great Lakes Restoration Initiative funding provided to the Michigan Department of Natural Resources [Grant F16AP01094] from the U.S. Fish and Wildlife Service and sub-awarded to Michigan State University. [ABSTRACT FROM AUTHOR]

A key uncertainty surrounding barrier removals in the Great Lakes is the response of invasive sea lamprey (Petromyzon marinus) populations to realized increases in available habitat for adfluvial species. We addressed this uncertainty by applying a management strategy evaluation model, originally developed to inform sea lamprey management in the Great Lakes, to forecast the effects of barrier removal on Lake Michigan sea lamprey abundances. We used this model to characterize the response to systematically increasing habitat availability and a specific proposed barrier removal. Our results suggest the removals allow novel production from newly opened habitat and, assuming a fixed budget for sea lamprey control, decrease the overall effectiveness of control, leading to disproportionate increases in abundance. The case study demonstrated that evaluating population effects only at the scale of watersheds directly affected by barrier removals would substantially underestimate effects at the scale of Lake Michigan. Similar population responses are possible when evaluating the effects on desired species. Our findings highlight the importance of considering trade-offs for barrier removals and selecting the appropriate scale for forecasting. Une source d'incertitude cle entourant le retrait de barrieres dans les Grands Lacs consiste en la reaction des populations de lamproies (Petromyzon marinus) envahissantes aux augmentations qui en decoulent des habitats disponibles pour les especes adfluviales. Nous avons examine cette source d'incertitude en appliquant un modele devaluation de strategies de gestion elabore au depart pour eclairer la gestion des lamproies dans les Grands Lacs, afin de predire les effets du retrait de barrieres sur les abondances de lamproies du lac Michigan. Nous avons utilise ce modele pour caracteriser la reaction a l'augmentation systematique de la disponibilite d'habitats et le retrait propose d'une barriere precise. Nos resultats indiqueraient que les retraits permettent une nouvelle production issue des habitats nouvellement ouverts et, en presumant que le budget pour la lutte contre les lamproies reste le meme, reduisent l'efficacite globale des mesures de lutte, menant a une augmentation disproportionnee de leur abondance. L'etude de cas demontre que revaluation des effets sur les populations seulement a l'echelle des bassins versants directement touches par les retraits de barrieres se traduirait par une sous-estimation importante des effets a l'echelle du lac Michigan. Des reactions similaires de populations sont possibles en ce qui concerne revaluation des effets sur des especes desirees. Nos constatations soulignent l'importance de tenir compte des compromis associes aux retraits de barrieres et de bien choisir l'echelle pour l'etablissement de predictions. [Traduit par la Redaction], Introduction Dams are ubiquitous features of watersheds throughout the world and historically provided many societal benefits, but they also serve as major barriers to migratory fish. Indeed, dams, hereinafter referred [...]

Pressure ulcers are common among people with spinal cord injury (SCI) and not only are costly to treat but also affect the quality of life of those affected by them. Despite a plethora of literature on prevention, there are few wellness studies focusing on the practices of people who do not develop pressure ulcers. This preliminary study sought to compare persons with spinal cord injury with consistent healthy skin histories to those with chronic pressure ulcer problems, focusing on behavioral habits of self-care. Data from 86 individuals 6 to 17 years postinjury were gathered by a mail and telephone survey investigating demographics and behavioral management lifestyle practices and factors attributed to success in preventing ulcers. Chi-square and follow-up analyses of variance indicated the group practices of those relatively ulcer free, who were female, were employed, weighed less, performed frequent pressure releases, experienced fewer ulcers during the first year, were less likely to smoke, consumed less alcohol, had fewer incontinence or moisture problems, had more sensation in the buttocks region, and were more physically active. Relevance to rehabilitation counselors in working with this population and addressing this debilitating problem is explored.

The St. Marys River (SMR) historically has been a major producer of sea lampreys (Petromyzon marinus) in the Laurentian Great Lakes. In the early 2000s, a decision analysis (DA) project was conducted to evaluate sea lamprey control policies for the SMR; this project suggested that an integrated policy of trapping, sterile male releases, and Bayluscide treatment was the most cost-effective policy. Further, it concluded that formal assessment of larval sea lamprey abundance and distribution in the SMR would be valuable for future evaluation of control strategies. We updated this earlier analysis, adding information from annual larval assessments conducted since 1999 and evaluating additional control policies. Bayluscide treatments continued to be critical for sea lamprey control, but high recruitment compensation minimized the effectiveness of trapping and sterile male release under current feasible ranges. Because Bayluscide control is costly, development of strategies to enhance trapping success remains a priority. This study illustrates benefits of an adaptive management cycle, wherein models inform decisions, are updated based on learning achieved from those decisions, and ultimately inform future decisions. Historiquement, la riviere St. Marys (SMR) a ete un important producteur de lamproies (Petromyzon marinus) dans le reseau des Grands Lacs laurentiens. Au debut des annees 2000, un projet d'analyse decisionnelle (AD) a ete mene pour evaluer les politiques de controle des lamproies pour la SMR; ce projet suggerait qu'une approche integree de piegeage, de lachers de males steriles et de traitements au Bayluscide constituait la politique la plus efficiente. Il concluait en outre que l'evaluation formelle de l'abondance et de la repartition des larves de lamproie dans la SMR serait utile pour l'evaluation future des strategies de controle. Nous avons mis a jour cette analyse en y ajoutant des donnees d'evaluations annuelles des larves menees depuis 1999 et en evaluant d'autres politiques de controle. Les traitements au Bayluscide ont continue de jouer un role essentiel dans le controle des lamproies, mais un recrutement compensatoire eleve a minimise l'efficacite du piegeage et des lachers de males steriles dans les conditions de faisabilite actuelles. Parce que le controle au Bayluscide est couteux, l'elaboration de strategies permettant d'ameliorer le succes du piegeage est une priorite. L'etude illustre les avantages d'un cycle de gestion adaptatif dans lequel les modeles eclairent les decisions, puis sont mis a jour a la lumiere des apprentissages decoulant de ces decisions pour ensuite eclairer de nouvelles decisions. [Traduit par la Redaction], Introduction Decision analysis (DA; Clemen and Reilly 2001) is a valuable tool for informing managers about expected performance of different decision choices in meeting management objectives, as well as identifying [...]

Explores how multimedia records, especially digital video, can enhance the analysis and presentation of research findings and can facilitate mixed-method research designs. Draws analogies between mixing methods and mixing technologies. (Author/SLD)

Improved methods are needed to evaluate barriers and traps for control and assessment of invasive sea lamprey (Petromyzon marinus) in the Great Lakes. A Bayesian state-space model provided reach-specific probabilities of movement, including trap capture and dam passage, for 148 acoustic tagged invasive sea lamprey in the lower Cheboygan River, Michigan, a tributary to Lake Huron. Reach-specific movement probabilities were combined to obtain estimates of spatial distribution and abundance needed to evaluate a barrier and trap complex for sea lamprey control and assessment. Of an estimated 21828 29 300 adult sea lampreys in the river, 0%-2%, or 0-514 untagged lampreys, could have passed upstream of the dam, and 46%- 61% were caught in the trap. Although no tagged lampreys passed above the dam (0/148), our sample size was not sufficient to consider the lock and dam a complete barrier to sea lamprey. Results also showed that existing traps are in good locations because 83%-96% of the population was vulnerable to existing traps. However, only 52%-69% of lampreys vulnerable to traps were caught, suggesting that traps can be improved. The approach used in this study was a novel use of Bayesian state- space models that may have broader applications, including evaluation of barriers for other invasive species (e.g., Asian carp (Hypophthalmichthys spp.)) and fish passage structures for other diadromous fishes. Il est necessaire d'ameliorer les methodes d'evaluation des barrieres et pieges utilises pour controler et evaluer la lamproie marine (Petromyzon marinus), une espece envahissante, dans les Grands Lacs. Un modele bayesien d'espace d'etats a produit des probabilites de deplacement, dont le piegeage et le passage de barrage, dans differents biefs pour 148 lamproies marines envahissantes dotees de marques acoustiques dans le cours inferieur de la riviere Cheboygan (Michigan), un affluent du lac Huron. Les probabilites de deplacement propres au bief ont ete combinees pour obtenir les estimations de la repartition spatiale et de l'abondance requises pour evaluer un complexe de barriere et piege pour le controle et l'evaluation des lamproies. Sur un nombre estime de 21828 a 29 300 lamproies adultes dans la riviere, de 0 % a 2 % des lamproies non marquees, soit de 0 a 514 poissons, pourraient etre passees en amont du barrage, et de 46 % a 61 % ont ete prises dans le piege. Bien qu'aucune lamproie marquee ne soit passee en amont du barrage (0/148), la taille de l'echantillon est trop petite pour permettre d'etablir que l'ecluse-barrage constitue une barriere completement etanche au passage des lamproies. Les resultats ont egalement demontre que les pieges existants sont bien situes, puisque de 83 % a 96 % de la population etait vulnerable aux pieges existants. Cependant, de 52 % a 69 % seulement des lamproies vulnerables aux pieges ont ete capturees, indiquant que ces pieges peuvent etre ameliores. L'approche employee constitue une utilisation novatrice des modeles bayesiens d'espace d'etats qui pourrait avoir des applications plus larges, notamment pour l'evaluation des barrieres au passage d'autres especes envahissantes (p. ex. carpe asiatique (Hypophthalmichthys spp.)) et des passes a poissons pour d'autres especes diadromes. [Traduit par la Redaction], Introduction The Laurentian Great Lakes were severely disrupted by the arrival of invasive sea lamprey (Petromyzon marinus) through the Welland Canal in the early 1900s (Smith and Tibbles 1980; Hansen [...]

Using a Bayesian modeling approach, we developed a multispecies statistical age-structured model to assess trade-offs between predatory demands and prey productivities, with the aim to inform management of top predators. Focusing on the Lake Michigan fish community, we assessed these trade-offs in terms of predation mortalities and productivities of alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) and functional responses of salmonines. Our predation mortality estimates suggested that salmonine consumption has been a major driver of prey dynamics, with sharp declines in alewife abundance in the 1950s-1980s and the 2000s coinciding with increased predation rates. Our functional response analysis indicated that feedback mechanisms are unlikely to help maintain a predator-prey balance, with Chinook salmon (Oncorhynchus tshawytscha) and lake trout (Salvelinus namaycush) consumption declining only at the lowest prey densities, while the other salmonines consumed prey at a maximum rate across all observed prey densities. This study demonstrates that a multispecies modeling approach combining stock assessment methods with explicit consideration of predator-prey interactions can provide a basis for tactical decision-making from a broader ecosystem perspective. Nous avons employe une approche de modelisation bayesienne pour elaborer un modele statistique multi-especes structure par age pour evaluer les compromis entre les demandes de predation et la productivite des proies, afin d'eclairer la gestion des predateurs de niveau trophique superieur. Dans le cadre de l'etude, axee sur la communaute de poissons du lac Michigan, nous avons evalue ces compromis en termes de moralite par predation et de productivite du gaspareau (Alosa pseudoharengus) et de l'eperlan (Osmerus mordax), ainsi que des reactions fonctionnelles de salmonines. Nos estimations de la mortalite par predation donnent a penser que la consommation des salmonines a joue un role important dans la dynamique des proies, de fortes baisses de l'abondance du gaspareau dans les annees 1950-1980, puis dans les annees 2000 coincidant avec des taux de predation accrus. Notre analyse des reactions fonctionnelles indique qu'il est peu probable que des mecanismes de retroaction contribuent au maintien d'un equilibre predateurs-proies, la consommation des saumons quinnats (Oncorhynchus tshawytscha) et des touladis (Salvelinus namaycush) ne diminuant que quand les densites de proies sont a leur plus faible, alors que la consommation des autres salmonines etait maximum pour toutes les densites de proies observees. L'etude demontre qu'une approche de modelisation multi-especes qui combine des methodes devaluation des stocks a la prise en consideration explicite des interactions predateurs-proies peut fournir la base d'une prise de decisions tactique dans une perspective ecosystemique large. [Traduit par la Redaction], Introduction Fisheries management has relied heavily on single-species stock assessment methods, wherein feedback interactions between target species and the rest of the ecosystem have been effectively ignored (Link and Garrison [...]

Variation among populations in life history and intrinsic population characteristics (i.e., population diversity) helps maintain resilience to environmental change and dampen interannual variability in ecosystem services. As a result, ecological variation, and the processes that generate it, is considered central to strategies for managing risks to ecosystems in an increasingly variable and uncertain world. However, characterizing population diversity is difficult, particularly in large and remote regions, which often prevents its formal consideration in management advice. We combined genetic stock identification of archived scale and tissue samples with state‐space run‐reconstruction models to estimate migration timing and annual return abundance for eight geographically and genetically distinct Chinook salmon populations within the Canadian portion of the Yukon River. We found that among‐population variation in migration timing and return abundances resulted in aggregate return migrations that were 2.1 times longer and 1.4 times more stable than if they had composed a single homogeneous population. We then fit state‐space spawner–recruitment models to the annual return abundances to characterize among‐population diversity in intrinsic productivity and population size and their consequences for the fisheries they support. Productivity and carrying capacity varied among populations by approximately 2.4‐fold (2.9 to 6.9 recruits per spawner) and three‐fold (8800 to 27,000 spawners), respectively. This diversity implies an equilibrium trade‐off between harvesting of the population aggregate and the conservation of individual populations whereby the harvest rate predicted to maximize aggregate harvests comes at the cost of overfishing ~40% of the populations but with a relatively low risk of extirpating the weakest ones. Our findings illustrate how population diversity in one of the largest salmon‐producing river basins in the world contributes to fishery stability and food security in a region where salmon have high cultural and subsistence value. More generally, our work demonstrates the utility of molecular analyses of archived biological material for characterizing diversity in biological systems and its benefits and consequences for trade‐offs in decision‐making. [ABSTRACT FROM AUTHOR]

The control of invasive sea lampreys (Petromyzon marinus) presents large-scale management challenges in the Laurentian Great Lakes. No modeling approach has been developed that describes spatial dynamics of lamprey populations. We developed and validated a spatial and age-structured model and applied it to a sea lamprey population in a large river in the Great Lakes basin. We considered 75 discrete spatial areas, included a stock-recruitment function, spatial recruitment patterns, natural mortality, chemical treatment mortality, and larval metamorphosis. Recruitment was variable, and an upstream shift in recruitment location was observed over time. From 1993 to 2011, recruitment, larval abundance, and the abundance of metamorphosing individuals decreased by 80%, 84%, and 86%, respectively. The model successfully identified areas of high larval abundance and showed that areas of low larval density contribute significantly to the population. Estimated treatment mortality was less than expected but had a large population-level impact. The results and general approach of this work have applications for sea lamprey control throughout the Great Lakes and for the restoration and conservation of native lamprey species globally. Le controle des lamproies marines (Petromyzon marinus), une espece envahissante, pose des defis agrande echelle en ce qui concerne sa gestion dans les Grands Lacs laurentiens. Aucune approche de modelisation n'a encore ete elaboree pour decrire la dynamique spatiale des populations de lamproies marines. Nous avons mis au point et valide un modele spatial structure selon l'age et l'avons applique a une population de lamproies marines dans une grande riviere du bassin versant des Grands Lacs. Le modele comprenait 75 aires discretes et integrait une fonction stock-recrutement, la distribution spatiale du recrutement, la mortalite naturelle, la mortalite par traitement chimique et la metamorphose des ammocetes. Le recrutement etait variable, et un deplacement vers l'amont du lieu de recrutement a ete observe dans le temps. De 1993 a 2011, le recrutement, l'abondance des ammocetes et l'abondance des individus en metamorphose ont diminue de 80 %, 84 % et 86 %, respectivement. Le modele a cerne avec succes les zones de forte abondance d'ammocetes et demontre une contribution significative des zones de faible abondance d'ammocetes a la population. Si la mortalite par traitement estimee etait plus faible que prevue, son impact a l'echelle de la population etait considerable. Les resultats et l'approche generale de l'etude peuvent etre appliques au controle des lamproies marines a la grandeur des Grands Lacs et aux efforts de retablissement et de conservation des lamproies indigenes partout dans le monde. [Traduit par la Redaction], Introduction Once an invasive species becomes firmly established, detailed information about population dynamics and areas of aggregation and high abundance is often necessary for successful control (Simberloff 2003). Incorporating the [...]

We used a three-dimensional coupled hydrodynamic-ecological model to investigate how lake currents can affect walleye (Sander vitreus) recruitment in western Lake Erie. Four years were selected based on a fall recruitment index: two high recruitment years (i.e., 1996 and 1999) and two low recruitment years (i.e., 1995 and 1998). During the low recruitment years, the model predicted that (i) walleye spawning grounds experienced destructive bottom currents capable of dislodging eggs from suitable habitats (reefs) to unsuitable habitats (i.e., muddy bottom), and (ii) the majority of newly hatched larvae were transported away from the known suitable nursery grounds at the start of their first feeding. Conversely, during two high recruitment years, predicted bottom currents at the spawning grounds were relatively weak, and the predicted movement of newly hatched larvae was toward suitable nursery grounds. Thus, low disturbance-based egg mortality and a temporal and spatial match between walleye first feeding larvae and their food resources were predicted for the two high recruitment years, and high egg mortality plus a mismatch of larvae with their food resources was predicted for the two low recruitment years. In general, mild westerly or southwesterly winds during the spawning-nursery period should favour walleye recruitment in the lake. Nous utilisons un modele tridimensionnel hydrodynamique et ecologique couple pour etudier comment les courants lacustres peuvent affecter le recrutement du dore (Sander vitreus) dans la region occidentale du lac Erie. Nous avons retenu quatre annees d'apres un coefficient de recrutement automnal, deux annees de fort recrutement (1996 et 1999) et deux annees de dores ont connu des courants de fond destructeurs capables de deloger les neufs des habitats favorables (recifs) et de les releguer dans des habitats inadequats (fonds boueux) et (ii) la majorite des larves nouveau-nees ont ete delogees des nourriceries favorables connues au debut de leur premiere alimentation. A l'inverse, les deux annees de recrutement important, les courants de fond predits sur les frayeres etaient relativement faibles et les deplacements predits des larves nouvellement ecloses se faisaient vers les nourriceries favorables. Ainsi, le modele predit une faible mortalite des neufs due A la perturbation et une coincidence temporelle et spatiale entre les larves de dores et leurs resources alimentaires lors de leur premiere alimentation pour les deux annees de fort recrutement, alors qu'il predit une forte mortalite des neufs et une separation des larves de leurs ressources alimentaires lors des deux annees de recrutement faible. En general, des vents doux de l'ouest ou du sud-ouest durant les periodes de fraye et de nourricerie devraient favoriser le recrutement des dores dans le lac. [Traduit par la Redaction], Introduction Walleye (Sander vitreus) populations in Lake Erie have supported substantial fisheries for nearly 200 years, and for much of this period, these populations have exhibited large fluctuations in abundance [...]