Accuracy of aerial telemetry in fisheries studies

Abstract.-Radiotelemetry has become an important method for examining movement patterns of fishes. The use of aircraft allows transmitter-implanted fish to be tracked over long distances and in areas difficult to access on the ground. However, the accuracy of aerially determined locations can limit the types of conclusions one can draw about fish habitat use. We utilized aerial telemetry while studying the effects of irrigation canals on a population of cutthroat trout Oncorhynchus clarkii. To determine the accuracy of aerially determined locations, we used a method common in terrestrial studies whereby transmitters are placed at known locations and then located by a naïve pilot. These aerially determined locations were then compared with the known locations of transmitters to determine the mean error associated with aerial telemetry. In our study, we found that aerially acquired location errors ranged from 22 to 426 m and had a mean of 178 m. In a review of recent studies that used aerial telemetry, we found that 15 of 34 (44%) terrestrial studies but only 4 of 17 (24%) aquatic studies reported an estimate of the error associated with aerial telemetry locations. The overall mean location error of these studies was 158 m. We urge aquatic biologists to consider location errors when using aerial telemetry, especially when making inferences about fish habitat use or movement patterns

Arrhythmic Manifestations of Cardiac Amyloidosis: Challenges in Risk Stratification and Clinical Management

Amyloidosis is a systemic disease characterized by extracellular deposits of insoluble amyloid in various tissues and organs. Cardiac amyloidosis is a frequent feature of the disease, causing a progressive, restrictive type of cardiomyopathy, and is associated with adverse clinical outcomes and increased mortality. The typical clinical presentation in patients with cardiac amyloidosis is heart failure (HF) with preserved ejection fraction. Most patients present with typical symptoms and signs of HF, such as exertional dyspnea, pretibial edema, pleural effusions and angina pectoris due to microcirculatory dysfunction. However, patients may also frequently encounter various arrhythmias, such as atrioventricular nodal block, atrial fibrillation and ventricular tachyarrhythmias. The management of arrhythmias in cardiac amyloidosis patients with drugs and devices is often a clinical challenge. Moreover, predictors of life-threatening arrhythmic events are not well defined. This review intends to give a deepened insight into the arrhythmic features of cardiac amyloidosis by discussing the pathogenesis of these arrhythmias, addressing the challenges in risk stratification and strategies for management in these patients

Ecological and social strategies for managing fisheries using the Resist-Accept- Direct (RAD) framework

Fisheries management is a complex task made even more challenging by rapid and unprecedented socioecological transformations associated with climate change. The Resist-Accept- Direct (RAD) framework can be a useful tool to support fisheries management in facing the high uncertainty and variability associated with aquatic ecosystem transformations. Here, RAD strategies are presented to address ecological goals for aquatic ecosystems and social goals for fisheries. These strategies are mapped on a controllability matrix which explores the ability to guide a system\u27s behaviour towards a desired state based on ecological responsiveness and societal receptivity to change. Understanding and improving the controllability of aquatic systems and fisheries can help managers to maintain the broadest suite of available RAD management strategies

Historic characteristics and mortality of patients in the Swiss Amyloidosis Registry

AIMS OF THE STUDY: Systemic amyloidoses are rare protein-folding diseases with heterogeneous, often nonspecific clinical presentations. To better understand systemic amyloidoses and to apply state-of-the-art diagnostic pathways and treatment, the interdisciplinary Amyloidosis Network was founded in 2013 at University Hospital Zurich. In this respect, a registry was implemented to study the characteristics and life expectancy of patients with amyloidosis within the area covered by the network. Patient data were collected retrospectively for the period 2005–2014 and prospectively from 2015 onwards. METHODS: Patients aged 18 years or older diagnosed with any subtype of systemic amyloidosis were eligible for inclusion if they were treated in one of the four referring centres (Zurich, Chur, St Gallen, Bellinzona). Baseline data were captured at the time of diagnosis. Follow-up data were assessed half-yearly for the first two years, then annually. RESULTS: Between January 2005 and March 2020, 247 patients were screened, and 155 patients with confirmed systemic amyloidosis were included in the present analysis. The most common amyloidosis type was light-chain (49.7%, n = 77), followed by transthyretin amyloidosis (40%, n = 62) and amyloid A amyloidosis (5.2%, n = 8). Most patients (61.9%, n = 96) presented with multiorgan involvement. Nevertheless, single organ involvement was seen in all types of amyloidosis, most commonly in amyloid A amyloidosis (75%, n = 6). The median observation time of the surviving patients was calculated by the reverse Kaplan-Meier method and was 3.29 years (95% confidence interval [CI] 2.33–4.87); it was 4.87 years (95% CI 3.14–7.22) in light-chain amyloidosis patients and 1.85 years (95% CI 1.48–3.66) in transthyretin amyloidosis patients, respectively. The 1-, 3- and 5-year survival rates were 87.0% (95% CI 79.4–95.3%), 68.5% (95% CI 57.4–81.7%) and 66.0% (95% CI 54.6–79.9%) respectively for light-chain amyloidosis patients and 91.2% (95% CI 83.2–99.8%), 77.0% (95% CI 63.4–93.7%) and 50.6% (95% CI 31.8–80.3%) respectively for transthyretin amyloidosis patients. There was no significant difference between the two groups (p = 0.81). CONCLUSION: During registry set-up, a more comprehensive work-up of our patients suffering mainly from light-chain amyloidosis and transthyretin amyloidosis was implemented. Survival rates were remarkably high and similar between light-chain amyloidosis and transthyretin amyloidosis, a finding which was noted in similar historic registries of international centres. However, further studies are needed to depict morbidity and mortality as the amyloidosis landscape is changing rapidly

Managing for RADical ecosystem change: applying the Resist-Accept- Direct (RAD) framework

Ecosystem transformation involves the emergence of persistent ecological or social–ecological systems that diverge, dramatically and irreversibly, from prior ecosystem structure and function. Such transformations are occurring at increasing rates across the planet in response to changes in climate, land use, and other factors. Consequently, a dynamic view of ecosystem processes that accommodates rapid, irreversible change will be critical for effectively conserving fish, wildlife, and other natural resources, and maintaining ecosystem services. However, managing ecosystems toward states with novel structure and function is an inherently unpredictable and difficult task. Managers navigating ecosystem transformation can benefit from considering broader objectives, beyond a traditional focus on resisting ecosystem change, by also considering whether accepting inevitable change or directing it along some desirable pathway is more feasible (that is, practical and appropriate) under some circumstances (the RAD framework). By explicitly acknowledging transformation and implementing an iterative RAD approach, natural resource managers can be deliberate and strategic in addressing profound ecosystem change

Movement patterns in inland cutthroat trout (Oncorhynchus clarki utah): management and conservation

Abstract: Knowledge of movement patterns is critical to the management and conservation of inland salmonids. We studied the movements of Bonneville cutthroat trout (Oncorhynchus clarki utah) in a drainage in western Wyoming, USA. Our objectives were to (i) characterize the postspawning movement patterns of adult Bonneville cutthroat trout, (ii) contrast postspawning and summer movement patterns, and (iii) identify factors that disrupt the movements of Bonneville cutthroat trout. Our data showed that postspawning movements of Bonneville cutthroat trout formed a continuum, with fish moving from 0.5 to 82.0 km. Postspawning distance was positively related to fish length. Despite the wide range of movement observed during the spring, fish did not move more than 0.5 km during the summer. A road culvert and an irrigation diversion dam did not seem to pose barriers to the upstream movement of Bonneville cutthroat trout to headwater spawning areas in the spring. However, 23% of radio-tagged fish in 2000 moved into the irrigation diversion ditch as they moved downstream after spawning and subsequently died there. Maintaining drainage connectivity is an important conservation concern for trout populations such as this one, where fish move between complementary spawning and summer habitats. Résumé : Une connaissance des patterns de déplacement des salmonidés à l'intérieur du continent est essentielle à leur conservation et leur gestion. Nous avons étudié les déplacements de la truite fardée de Bonneville (Oncorhynchus clarki utah) dans un bassin versant de l'ouest du Wyoming, États-Unis. Nos objectifs étaient (i) de décrire les patterns de déplacement après la fraye des truites fardées de Bonneville adultes, (ii) de comparer les patterns de déplacement après la fraye et ceux de l'été et (iii) d'identifier les facteurs qui perturbent les déplacements de la truite fardée de Bonneville. Nos données indiquent que les déplacements des truites fardées de Bonneville après la fraye forment un continuum, les poissons se déplaçant de 0,5 à 82,0 km. La distance parcourue après la fraye est fonction de la longueur du poisson. Malgré l'étendue importante des déplacements enregistrés au printemps, les poissons ne se déplacent pas plus de 0,5 km en été. Un ponceau de route et un canal de dérivation d'irrigation ne semblent pas former de barrière à la remontée des truites fardées de Bonneville vers les sites de fraye d'amont au printemps. Cependant, 23 % des poissons porteurs d'émetteurs radio en 2000 ont pénétré dans le fossé de dérivation d'irrigation lors de leur descente vers l'aval après la fraye et y sont morts éventuellement. Le maintien de la connectivité du réseau hydrographique est un problème important pour la conservation d'une population de truites comme celle-ci, chez laquelle les poissons se déplacent entre des habitats de fraye et des habitats d'été qui sont complémentaires. [Traduit par la Rédaction] Schrank and Rahel 153

Factors influencing summer movement patterns of Bonneville cutthroat trout (Oncorhynchus clarkii utah)

We used multiple approaches to study summer movement patterns of Bonneville cutthroat trout (Oncorhynchus clarkii utah) in the Thomas Fork drainage of western Wyoming, USA. Our objectives were to (i) document summer movement patterns of cutthroat trout, especially as related to the concepts of local turnover and displacement distances, (ii) determine if fish size and condition were related to mobility, and (iii) compare summer movement patterns between years. Large fish (270-384 mm total length) monitored by radiotelemetry showed little movement during the summer as evidenced by a maximum displacement distance of \u3c 300 m and a low turnover rate among locations (0.21). For a broad size range of fish marked with visual implant tags (173-390 mm total length) in three study reaches, displacement distances were again low but turnover rate was high (\u3e 0.50 in most study reaches). This high turnover rate seemed to be driven mainly by movement among smaller fish as mobility declined with increasing fish size. Mobility also declined with decreasing body condition. Turnover rate in study reaches was higher during the summer of 1999 when stream flows were higher and water temperatures were cooler compared with the summer of 2000. © 2006 NRC