Step-by-step recommendations utilizing four-dimensional intracardiac echocardiography in left atrial appendage procedures.

INTRODUCTION: Four-dimensional (4D) intracardiac echocardiography (ICE) is a novel cardiac imaging modality that has been applied to various workflows, including catheter ablation, tricuspid valve repair, and left atrial appendage occlusion (LAAO). The use of this type of advanced ICE imaging may ultimately allow for the replacement of transesophageal echocardiography (TEE) for LAAO, providing comparable imaging quality while eliminating the need for general anesthesia. METHODS: Based on our initial clinical experience with 4D ICE in LAAO, we have developed an optimized workflow for the use of the NUVISION™ 4D ICE Catheter in conjunction with the GE E95 and S70N Ultrasound Systems in LAAO. In this manuscript, we provide a step-by-step guide to using 4D ICE in conjunction with compatible imaging consoles. We have also evaluated the performance of 4D ICE with the NUVISION Ultrasound Catheter versus TEE in one LAAO case and present those results here. RESULTS: In our comparison of 4D ICE using our optimized workflow with TEE in an LAAO case, ICE LAA measurements were similar to those from TEE. The best image resolution was seen via ICE in 2-dimensional and multislice modes (triplane and biplane). The FlexiSlice multiplanar reconstruction tool, which creates an en-face image derived from a 4D volume set, also provided valuable information but yielded slightly lower image quality, as expected for these volume-derived images. For this case, comparable images were obtained with TEE and ICE but with less need to reposition the ICE catheter. CONCLUSION: The use of optimized 4D ICE catheter workflow recommendations allows for efficient LAAO procedures, with higher resolution imaging, comparable to TEE.

Feasibility of implementing an integrated long-term database to advance ecosystem-based management in the Laurentian Great Lakes basin.

The North American Great Lakes have been experiencing dramatic change during the past half-century, highlighting the need for holistic, ecosystem-based approaches to management. To assess interest in ecosystem-based management (EBM), including the value of a comprehensive public database that could serve as a repository for the numerous physical, chemical, and biological monitoring Great Lakes datasets that exist, a two-day workshop was organized, which was attended by 40+ Great Lakes researchers, managers, and stakeholders. While we learned during the workshop that EBM is not an explicit mission of many of the participating research, monitoring, and management agencies, most have been conducting research or monitoring activities that can support EBM. These contributions have ranged from single-resource (-sector) management to considering the ecosystem holistically in a decision-making framework. Workshop participants also identified impediments to implementing EBM, including: 1) high anticipated costs; 2) a lack of EBM success stories to garner agency buy-in; and 3) difficulty in establishing common objectives among groups with different mandates (e.g., water quality vs. fisheries production). We discussed as a group solutions to overcome these impediments, including construction of a comprehensive, research-ready database, a prototype of which was presented at the workshop. We collectively felt that such a database would offer a cost-effective means to support EBM approaches by facilitating research that could help identify useful ecosystem indicators and management targets and allow for management strategy evaluations that account for risk and uncertainty when contemplating future decision-making.

Long-term ecological research in freshwaters enabled by regional biodiversity collections, stable isotope analysis, and environmental informatics.

Biodiversity collections are experiencing a renaissance fueled by the intersection of informatics, emerging technologies, and the extended use and interpretation of specimens and archived databases. In this article, we explore the potential for transformative research in ecology integrating biodiversity collections, stable isotope analysis (SIA), and environmental informatics. Like genomic DNA, SIA provides a common currency interpreted in the context of biogeochemical principles. Integration of SIA data across collections allows for evaluation of long-term ecological change at local to continental scales. Challenges including the analysis of sparse samples, a lack of information about baseline isotopic composition, and the effects of preservation remain, but none of these challenges is insurmountable. The proposed research framework interfaces with existing databases and observatories to provide benchmarks for retrospective studies and ecological forecasting. Collections and SIA add historical context to fundamental questions in freshwater ecological research, reference points for ecosystem monitoring, and a means of quantitative assessment for ecosystem restoration.

The mental health effects of changing from insecure to secure visas for refugees.

OBJECTIVE: In response to growing numbers of refugees worldwide, host governments are increasingly implementing temporary protection policies; however, little is known regarding the mental health impact of these policies. This online longitudinal study investigated whether refugees who transitioned from low visa security (e.g. short-term transient visas) to medium (e.g. temporary protection visas) or high visa (e.g. permanent visas) security showed changes in depression symptoms, social difficulties and immigration-related fears. METHODS: Participants were 1,201 refugees and asylum-seekers from Arabic, Farsi, Tamil or English-speaking backgrounds. Study variables were measured prior to and after change in visa status (6 months apart). RESULTS: Refugees who transitioned from low to medium security visas showed reduced immigration-related fear (B = -0.09, 95% confidence interval = -0.29 to -0.06), but no change in depression symptoms or social difficulties compared to those who retained low visa security. Refugees who transitioned from low to high security visas showed reduced depression symptoms (B = -0.02, 95% confidence interval = -0.04 to -0.01), social difficulties (B = -0.04, 95% confidence interval = -0.05 to -0.01) and immigration-related fear (B = -0.03, 95% confidence interval = -0.06 to -0.01) compared to those who retained low visa security. CONCLUSION: Findings indicate that the increased security afforded by temporary protection policies (vs short-term transient visas) did not translate into improved mental health and social outcomes for refugees. In contrast, permanent protection was associated with significant improvements in psychological and social functioning. These results have important policy implications for countries who have committed to protect and facilitate improved mental health among refugees.

The longitudinal association between moral injury appraisals and psychological outcomes in refugees.

BACKGROUND: Refugees report a diverse array of psychological responses following persecution and displacement. Little is known, however, regarding the mechanisms that underlie differential psychological reactions in refugees. This study investigated the longitudinal impact of negative moral appraisals about one's own actions [i.e. moral injury-self (MI-self) appraisals] and others' actions [i.e. moral injury-other (MI-others) appraisals] on a variety of psychological symptoms over a period of 6 months. METHODS: Participants were 1085 Arabic, Farsi, Tamil, or English-speaking refugees who completed a survey at baseline and 6 months later either on-line or via pen-and-paper. The survey indexed demographic factors, exposure to potentially traumatic events (PTEs), exposure to ongoing stressors, MI-other appraisals, MI-self appraisals, re-experiencing and arousal symptoms, and feelings of sadness, anger and shame. RESULTS: Findings indicated that, after controlling for demographics, PTE exposure and ongoing stressors, MI-other appraisals predicted increased re-experiencing and hyperarousal symptoms, and feelings of sadness and shame. MI-self appraisals predicted decreased feelings of shame, and decreased re-experiencing symptoms. In contrast, psychological symptoms at baseline did not as strongly influence MI appraisals 6 months later. CONCLUSIONS: These findings highlight the important role that cognitive appraisals of adverse events play in the longitudinal course of psychological symptoms. These results thus have important implications for the development of tailored psychological interventions to alleviate the mental health burden held by refugees.

Context, coping, and mental health in refugees living in protracted displacement.

There is currently an unprecedented number of forcibly displaced people worldwide. Little is known, however, about how external stressors and internal coping strategies intersect to influence mental health in displaced refugees, particularly whether specific types of coping strategies are more or less effective across different levels of external stress. This study aimed to understand whether positive and negative internal coping strategies were differentially associated with mental health across high and low levels of external stressors in displaced refugees. Participants were 1,216 refugees living in Indonesia who completed an online survey indexing demographic characteristics, exposure to ongoing stressors, positive psychological coping strategies (i.e., cognitive flexibility, self-efficacy, and hope), negative psychological coping strategies (i.e., rumination and intolerance of uncertainty), psychological symptoms (i.e., posttraumatic stress disorder, depression, and anxiety) and mental health-related quality of life. Participants (27.3% female, Mage = 30.52 years) were from Arabic-, Farsi-, Tamil-, Somali-, Dari-, and English-speaking backgrounds. Results of latent moderated structural equation modeling indicated that the association between negative psychological coping strategies and poorer mental health was stronger at higher levels of stress, whereas the association between positive psychological coping strategies and better quality of life was stronger at lower levels of stress. These findings provide evidence in support of tailored approaches that integrate interventions addressing external stressors and internal coping strategies to support positive mental health and enhanced quality of life in displaced refugees.

Mercury source changes and food web shifts alter contamination signatures of predatory fish from Lake Michigan.

To understand the impact reduced mercury (Hg) loading and invasive species have had on methylmercury bioaccumulation in predator fish of Lake Michigan, we reconstructed bioaccumulation trends from a fish archive (1978 to 2012). By measuring fish Hg stable isotope ratios, we related temporal changes in Hg concentrations to varying Hg sources. Additionally, dietary tracers were necessary to identify food web influences. Through combined Hg, C, and N stable isotopic analyses, we were able to differentiate between a shift in Hg sources to fish and periods when energetic transitions (from dreissenid mussels) led to the assimilation of contrasting Hg pools (2000 to present). In the late 1980s, lake trout δ202Hg increased (0.4‰) from regulatory reductions in regional Hg emissions. After 2000, C and N isotopes ratios revealed altered food web pathways, resulting in a benthic energetic shift and changes to Hg bioaccumulation. Continued increases in δ202Hg indicate fish are responding to several United States mercury emission mitigation strategies that were initiated circa 1990 and continued through the 2011 promulgation of the Mercury and Air Toxics Standards rule. Unlike archives of sediments, this fish archive tracks Hg sources susceptible to bioaccumulation in Great Lakes fisheries. Analysis reveals that trends in fish Hg concentrations can be substantially affected by shifts in trophic structure and dietary preferences initiated by invasive species in the Great Lakes. This does not diminish the benefits of declining emissions over this period, as fish Hg concentrations would have been higher without these actions.

Setting an agenda to catalyze research in the social and organizational dimensions of Great Lakes remediation, restoration, and revitalization.

The Great Lakes region was once a hub of industry and innovation that provided wealth and identity to the region. Economic upheavals have left the region trying to recreate economies and cleanup degraded environments. There have been multiple, overlapping efforts to change these conditions and create a new narrative for the region through environmental remediation, habitat restoration, and community revitalization on the path towards resilience. The elements that contribute to success are organized differently in different places, and are not always identified or characterized in the environmental literature. Trying to fill this conceptual gap is critical because landscape-scale environmental cleanup has been delivered at the local scale through various partnerships and arrangements. Thus, this special collection of articles in the Journal of Great Lakes Research explores how individuals, organizations, and communities are engaging in the complex process of environmental cleanup and revitalization throughout the region. This collection of articles represents a range of approaches to unpack how people are navigating and contributing to this regenerative process from quantitative studies at the regional scale that characterize global patterns to in-depth qualitative studies that identify and characterize the processes that unfold in specific places to change our environments both ecologically and socially. These articles represent the broad experience unfolding in the region to understand these activities through research and navigate them through practice. This collection will add new dimensions to Great Lakes research by including the individuals, organizations, and agencies as components of the ecosystem.

Enhanced Susceptibility of Methylmercury Bioaccumulation into Seston of the Laurentian Great Lakes.

Mercury concentrations in the Laurentian Great Lakes waters are among the lowest reported in the literature, while game fish concentrations approach consumption advisory limits, particularly in Lakes Superior, Huron, and Michigan, indicating efficient methylmercury transfer from water to game fish. To determine if increased transfer efficiency is evident within the lower food web, we measured (2010-2018) mercury and dissolved organic carbon (DOC) in water, and in size-sieved seston, dietary tracers (carbon and nitrogen isotope ratios), phytoplankton methylmercury bioaccumulation, and methylmercury biomagnification between increasing seston size fractions. We observed consistently low filter-passing methylmercury (<0.010 ng L-1) and comparatively variable DOC (1.1 to 3.4 mg L-1) concentrations. Methylmercury biomagnification factors between size-sieved seston were similar between lakes. Bioaccumulation factors in phytoplankton were among the highest in the literature (log 5.5 to 6.1), exceeding those in oceans, smaller lakes, and streams, and was influenced by DOC. Higher bioaccumulation rates increase the susceptibility of methylmercury accumulation into the food web. Because mercury is dominantly delivered to the Great Lakes through the atmosphere and the biota therein is highly susceptible to methylmercury uptake, we propose that the Laurentian Great Lakes are excellent sentinels to trace the success of efforts to decrease global mercury emissions (e.g., Minamata Treaty) in the future.

Dietary Niche and Growth Rate of the Nonnative Tubenose Goby (Proterorhinus semilunaris) in the Lake Superior Basin.

The tubenose goby (Proterorhinus semilunaris) entered the Great Lakes in the 1990s via ballast water, but remains poorly studied within North America, making it difficult to predict its effects on native ecosystems. Dietary breadth and somatic growth rate have important ramifications for survival, competitiveness, and dispersal ability of a fish species, and thereby its ecological impact. We studied diet and growth of age-0 tubenose goby within the St. Louis River, a tributary to Lake Superior that contains the largest population within the Lake Superior basin. We sampled tubenose gobies from shallow, vegetated habitat during summer and fall. Stomach contents were identified and weighed to measure fullness and dietary breadth between seasons and several locations. We aged fish based on otolith daily increments to model somatic growth. Diet was dominated by isopods and amphipods, and dietary breadth was low and not significantly different between locations and seasons. Tubenose goby diet strongly overlapped with that of tadpole madtom (Noturus gyrinus), a native, demersal species. We tested several candidate growth models; the Gompertz Growth Function was the most parsimonious model among those examined. The model demonstrates that tubenose goby obtains a small maximum size and is short-lived. We conclude that tubenose goby presents a unique risk to the Great Lakes and other freshwater bodies because their life history is typical of invasive species, their diet overlaps with native fish, and because they occupy shallow, vegetated habitat which functions as both nursery and foraging habitat for many native fishes.

Resolving taxonomic ambiguities: effects on rarity, projected richness, and indices in macroinvertebrate datasets.

Biodiversity information is an important basis for ecological research and environmental assessment, and can be impacted by choices made in the manipulation and analysis of taxonomic data. Such choices include methods for resolving multiple redundant levels of taxonomic resolution, as typically arise with morphological identification of damaged or immature aquatic macro-invertebrates. In particular, the effects of these processing choices on number of rare taxa are poorly understood yet potentially significant to the estimation of projected taxa richness and related evaluations such as biodiversity conservation value and survey sufficiency. Using aquatic macroinvertebrate data collected for two nearshore areas of Lake Superior, we determined how multiple methods of resolving taxonomic redundancies influence two commonly-used estimates of projected richness, Chao1 and Chao2, which hinge on the ratio of taxa that are singletons to doubletons (i.e., just one versus two individuals found) or uniques versus duplicates (i.e., just one versus two occurrences). We also determined how choice of ambiguous taxa method, including some modified specifically to retain rare taxa and others taken from the literature, influenced effort to reach 95% of projected richness, site-level richness and abundance, and representative invertebrate IBI scores. We found that Chao1 was more sensitive to method choice than Chao2, because singleton and doubleton status was more frequently affected when taxa were deleted, merged, or re-assigned in the process of resolving taxonomic redundancies than was unique and duplicate status. Methods that eliminated redundant taxa at the site scale but not the study-area scale tended to overinflate study area and projected richness, and resulted in a significant loss of abundance. The method that aggregated or deleted redundant taxa depending on abundance resulted in a decrease in site and study area richness, abundance, and an underestimation of projected richness. Methods which re-assigned parents to common children retained a majority of richness and abundance information and a more realistic estimate of projected taxa richness; however, the identity of poorly-identified parents was imputed. All methods resulted in little effect to typical IBI scores. Overall, no one method is fully capable of removing spurious richness at the study-area scale while preserving all taxa occurrence, abundance and rarity patterns. Therefore, the most appropriate method for making comparisons among sites may be different than the most appropriate method for comparing among surveys or among study areas, or if a goal is to estimate projected taxa richness or retain rare taxa information.

Goals, beneficiaries, and indicators of waterfront revitalization in Great Lakes Areas of Concern and coastal communities.

Cleanup of Great Lakes Areas of Concern (AOCs) restores environmental benefits to waterfront communities and is an essential condition for revitalization. We define waterfront revitalization as policies or actions in terrestrial waterfront or adjacent aquatic areas that promote improvements in human socioeconomic well-being while protecting or improving the natural capital (the stocks of natural assets, biodiversity) that underlies all environmental, social, and economic benefits. Except for economic measures such as development investments, visitation rates, or commercial activity, evidence of waterfront revitalization in the Great Lakes is mostly anecdotal. We offer a perspective on waterfront revitalization that links indicators and metrics of sustainable revitalization to community goals and human beneficiaries. We compiled environmental, social, economic, and governance indicators and metrics of revitalization, many of which are based on or inspired by Great Lakes AOC case studies and community reutilization or sustainability plans. We highlight the role of indicators in avoiding unintended consequences of revitalization including environmental degradation and social inequity. Revitalization indicators can be used in planning for comparing alternative designs, and to track restoration progress. The relevancy of specific indicators and metrics will always depend on the local context.

Relative contributions of nearshore and wetland habitats to coastal food webs in the Great Lakes.

Hydrologic linkages among coastal wetland and nearshore areas allow coastal fish to move among the habitats, which has led to a variety of habitat use patterns. We determined nutritional support of coastal fishes from 12 wetland-nearshore habitat pairs using stable isotope analyses, which revealed differences among species and systems in multi-habitat use. Substantial (proportions > 0.30) nutrition often came from the habitat other than that in which fish were captured. Nearshore subsidies to coastal wetlands indicate wetlands are not exclusively exporters of energy and materials; rather, there is reciprocity in the mutual energetic support of nearshore and wetland food webs. Coastal wetland hydrogeomorphology influenced the amount of multi-habitat use by coastal fishes. Fishes from systems with relatively open interfaces between wetland and nearshore habitats exhibited less nutritional reliance on the habitat in which they were captured, and higher use of resources from the adjacent habitat. Comparisons of stable isotope analyses of nutrition with otolith analyses of occupancy indicated nutritional sources often corresponded with habitat occupancy; however, disparities among place of capture, otolith analyses, and nutritional analyses indicated differences in the types of support those analyses inform. Disparities between occupancy information and nutritional information can stem from movements for support functions other than foraging. Together, occupancy information from otolith microchemistry and nutritional information from stable isotope analyses provide complementary measures of the use of multiple habitats by mobile consumers. This work underscores the importance of protecting or restoring a diversity of coastal habitats and the hydrologic linkages among them.

Dreissena veligers in western Lake Superior - inference from new low-density detection.

The notion that Lake Superior proper is inhospitable to dreissenid mussel survival has been challenged by recent finds on shipwrecks and rocky reefs in the Apostle Islands region. Motivated by concerns surrounding these finds, we conducted an intensive sampling campaign of Apostle Islands waters in 2017 to understand Dreissena prevalence and distribution. The 100-site effort combined random and targeted sites and collected zooplankton, benthos, video, environmental DNA, and supporting water quality data. We did not find settled Dreissena in any video footage or benthos samples, and quantitative PCR applied to eDNA samples was negative for Dreissena. Dreissena veligers were found in almost half the zooplankton samples but at orders of magnitude lower densities than reported from other Laurentian Great Lakes. Veligers were most prevalent around the western islands and associated with shallower depths and slightly higher phosphorus and chlorophyll, but did not spatially match known (still very localized) settled Dreissena colonies. This is the first study to conduct veliger-targeted sampling in western Lake Superior and the first to report consistent detection of veligers there. We speculate that these Apostle Islands veligers are not a new locally-spawned component of the zooplankton community, but instead are transported from an established population in the St. Louis River estuary (~100 km away) by longshore currents; i.e., low-density propagule pressure that may have been present for years. Small-mesh zooplankton data collected along a gradient from the Apostle Islands to the St. Louis River estuary and enumerated with thorough veliger searching would help elucidate these alternatives.

The relationship between moral injury appraisals, trauma exposure, and mental health in refugees.

BACKGROUND: Refugees are often exposed to multiple traumatic experiences, leading to elevated rates of psychological disorders. There is emerging evidence that appraisals of traumatic events as violating deeply held moral beliefs and frameworks (i.e., moral injury) impact negatively on refugee mental health. Despite this, no research has systematically investigated moral injury appraisals in refugees. METHOD: Participants were 222 refugees from diverse backgrounds who had recently resettled in Australia. They completed measures of mental health in Arabic, Farsi, Tamil, or English through an online survey. This study first investigated the factor structure of the Moral Injury Appraisals Scale (MIAS), and then examined the relationship between the moral injury factors and key predictor (age, gender, trauma exposure) and outcome (Posttraumatic stress disorder [PTSD] symptom clusters, anger, and depression) variables. RESULTS: Confirmatory factor analyses of the MIAS supported a two-factor model, comprising a Moral Injury-Other (MI-Other) factor (i.e., interpreting the violation as being enacted by others) and a Moral Injury-Self (MI-Self) factor (i.e., interpreting the violation as being enacted by oneself). Structural equation modeling analyses indicated that both factors were predicted by higher trauma exposure, and both predicted more severe anger and depression. Notably, while MI-Other was associated with more severe PTSD, MI-Self was associated with lower levels of intrusions. CONCLUSION: These results suggest that there may be subtypes of moral injury appraisals that are associated with different mental health outcomes. These findings have potential implications for designing treatments that address the psychological impact of the refugee experience.

Early detection monitoring for aquatic non-indigenous species: Optimizing surveillance, incorporating advanced technologies, and identifying research needs.

Following decades of ecologic and economic impacts from a growing list of nonindigenous and invasive species, government and management entities are committing to systematic early- detection monitoring (EDM). This has reinvigorated investment in the science underpinning such monitoring, as well as the need to convey that science in practical terms to those tasked with EDM implementation. Using the context of nonindigenous species in the North American Great Lakes, this article summarizes the current scientific tools and knowledge - including limitations, research needs, and likely future developments - relevant to various aspects of planning and conducting comprehensive EDM. We begin with the scope of the effort, contrasting target-species with broad-spectrum monitoring, reviewing information to support prioritization based on species and locations, and exploring the challenge of moving beyond individual surveys towards a coordinated monitoring network. Next, we discuss survey design, including effort to expend and its allocation over space and time. A section on sample collection and analysis overviews the merits of collecting actual organisms versus shed DNA, reviews the capabilities and limitations of identification by morphology, DNA target markers, or DNA barcoding, and examines best practices for sample handling and data verification. We end with a section addressing the analysis of monitoring data, including methods to evaluate survey performance and characterize and communicate uncertainty. Although the body of science supporting EDM implementation is already substantial, research and information needs (many already actively being addressed) include: better data to support risk assessments that guide choice of taxa and locations to monitor; improved understanding of spatiotemporal scales for sample collection; further development of DNA target markers, reference barcodes, genomic workflows, and synergies between DNA-based and morphology-based taxonomy; and tools and information management systems for better evaluating and communicating survey outcomes and uncertainty.

Fish tissue lipid-C:N relationships for correcting δ(13) C values and estimating lipid content in aquatic food-web studies.

RATIONALE: Normalizing δ(13) C values of animal tissue for lipid content is necessary to accurately interpret food-web relationships from stable isotope analysis. To reduce the effort and expense associated with chemical extraction of lipids, various studies have tested arithmetic mass balance to mathematically normalize δ(13) C values for lipid content; however, the approach assumes that lipid content is related to the tissue C:N ratio. METHODS: We evaluated two commonly used models for estimating tissue lipid content based on C:N ratio (a mass balance model and a stoichiometric model) by comparing model predictions to measure the lipid content of white muscle tissue. We then determined the effect of lipid model choice on δ(13) C values normalized using arithmetic mass balance. To do so, we used a collection of fish from Lake Superior spanning a wide range in lipid content (5% to 73% lipid). RESULTS: We found that the lipid content was positively related to the bulk muscle tissue C:N ratio. The two different lipid models produced similar estimates of lipid content based on tissue C:N, within 6% for tissue C:N values <7. Normalizing δ(13) C values using an arithmetic mass-balance equation based on either model yielded similar results, with a small bias (<1‰) compared with results based on chemical extraction. CONCLUSIONS: Among-species consistency in the relationship between fish muscle tissue C:N ratio and lipid content supports the application of arithmetic mass balance to normalize δ(13) C values for lipid content. The uncertainty associated with both lipid extraction quality and choice of model parameters constrains the achievable precision of normalized δ(13) C values to about ±1.0‰.

Navigating University Openness in Research Policy Inconsistent with Indigenous Data Sovereignty: A Case Analysis.

Indigenous nations and communities in the United States have rights as sovereign governments to exercise control and ownership over all data and information generated by or from the tribes, tribal members, or tribal resources. Indigenous nations exercise these rights through data ownership policies established in response to unethical research practices in research involving Indigenous communities. Most universities in the U.S. have "openness in research" policies to ensure academic freedom to publish freely, exercised by retaining university control of data. Here, we describe our study of cultural ecosystem services in the St. Louis River estuary region (Nagaajiwanaang in the language Ojibwemowin) in Duluth, Minnesota, and Superior, Wisconsin, U.S., an area that includes portions of the 1854 and 1842 Ceded Territories and reservation lands of a local band of Ojibwe (hereafter referred to as "the Band"). In this university-led, Band-supported study, both the university and the Band sought ownership of data collected based on their respective policies, resulting in a research delay of nearly a year. We found that open research policies that do not consider Indigenous sovereignty can hamper collaboration between university researchers and tribal nations, even when there is broad agreement on research goals and objectives. University open research policies that do not explicitly address Indigenous sovereignty fall short of the open research principles they intend to support and should be revised. Formal adoption of principles for ethical research with sovereign tribal governments by universities is needed to improve coordination and trust among university and tribal researchers and members.

The benthic food web connects the estuarine habitat mosaic to adjacent ecosystems.

Energy flows from land to sea and between pelagic and benthic environments have the potential to increase the connectivity between estuaries and adjacent ecosystems as well as among estuarine habitats. To identify such energy flows and the main trophic pathways of energy transfer in the Minho River estuary, we investigated the spatial and temporal fluctuations of carbon and nitrogen stable isotope ratios in benthic (and their potential food sources) and epibenthic consumers. Sampling was conducted along the estuarine salinity gradient from winter to summer of 2011. We found that the carbon (δ13C = 13C/12C) and nitrogen (δ15N = 15N/14N) stable isotope ratios of the most abundant benthic and epibenthic consumers varied along the salinity gradient. The δ13C values increased seaward, whereas the opposite pattern was found for the δ15N, especially during the summer. The stable isotope ratios revealed two trophic pathways in the Minho estuary food web. The first pathway is supported by phytoplankton and represented by filter feeders such as zooplankton and some deposit feeders, particularly amphipods and polychaetes. The second pathway is supported by detritus and composed essentially of deposit feeders, which by being consumed, allow detritus to be incorporated into higher trophic levels. Spatial and temporal feeding variations in the estuarine benthic food web are driven by hydrology and proximity to adjacent ecosystems (terrestrial, marine). During high river discharge periods, the δ13CPOC (ca. -28‰) and C: NPOM (>10) values suggested an increase of terrestrial-derived OM to the particulate OM pool, which was then used by suspension feeders. During low river discharge periods, marine intrusion increased upriver, which was reflected in benthic consumers' 13C-enriched stable isotope values. No relationship was found between food quality (phytoplankton vs. detritus) and food chain length because the lowest and highest values were associated with freshwater and saltmarsh areas, respectively, both dominated by the detrital pathway. This study demonstrates that benthic consumers enhance the connectivity between estuaries and its adjacent ecosystems by utilizing subsidies of terrestrial and marine origin and that benthic-pelagic coupling is an important energy transfer mechanism to the benthic food web.

Using mercury stable isotope fractionation to identify the contribution of historical mercury mining sources present in downstream water, sediment and fish.

Ecosystems downstream of mercury (Hg) contaminated sites can be impacted by both localized releases as well as Hg deposited to the watershed from atmospheric transport. Identifying the source of Hg in water, sediment, and fish downstream of contaminated sites is important for determining the effectiveness of source-control remediation actions. This study uses measurements of Hg stable isotopes in soil, sediment, water, and fish to differentiate between Hg from an abandoned Hg mine from non-mine-related sources. The study site is located within the Willamette River watershed (Oregon, United States), which includes free-flowing river segments and a reservoir downstream of the mine. The concentrations of total-Hg (THg) in the reservoir fish were 4-fold higher than those further downstream (>90 km) from the mine site in free-flowing sections of the river. Mercury stable isotope fractionation analysis showed that the mine tailings (δ202Hg: -0.36‰ ± 0.03‰) had a distinctive isotopic composition compared to background soils (δ202Hg: -2.30‰ ± 0.25‰). Similar differences in isotopic composition were observed between stream water that flowed through the tailings (particulate bound δ202Hg: -0.58‰; dissolved: -0.91‰) versus a background stream (particle-bound δ202Hg: -2.36‰; dissolved: -2.09‰). Within the reservoir sediment, the Hg isotopic composition indicated that the proportion of the Hg related to mine-release increased with THg concentrations. However, in the fish samples the opposite trend was observed-the degree of mine-related Hg was lower in fish with the higher THg concentrations. While sediment concentrations clearly show the influence of the mine, the relationship in fish is more complicated due to differences in methylmercury (MeHg) formation and the foraging behavior of different fish species. The fish tissue δ13C and Δ199Hg values indicate that there is a higher influence of mine-sourced Hg in fish feeding in a more sediment-based food web and less so in planktonic and littoral-based food webs. Identifying the relative proportion of Hg from local contaminated site can help inform remediation decisions, especially when the relationship between total Hg concentrations and sources do not show similar covariation between abiotic and biotic media.