Bioenergetic consequences of repeated catch-and-release fisheries interactions on adult steelhead across a range of ecologically relevant water temperatures.

The biological consequences of catch-and-release angling have been studied for decades, yet little is known about the compounding effects of repeated recreational fisheries recaptures on the physiology and behaviour of angled fish. Using heart rate biologgers and behavioural assays, this study investigated the physiological and behavioural consequences of multiple simulated angling events (i.e., repeated stressors) on female steelhead (Oncorhynchus mykiss), under current (6 °C) and future (11 °C) water temperature scenarios. While steelhead in the warmer water temperature scenario demonstrated alterations in cardiac function (e.g., increases in maximum heart rate and scope of heart rate) and evidence of behavioural impairments (e.g., decreases in chase activity and landing time) over the course of two simulated angling events, cold water treated fish had negligible change. Fish subjected to two simulated angling events under warm water temperature conditions tended to demonstrate an increase in recovery time and scope for heart rate, and a decrease in resting heart rate. A second experiment was conducted to test for sex-specific differences in the heart rate response of steelhead subjected to an increase in water temperature. Females demonstrated a higher scope for heart rate when compared to males during the event and during recovery. More work is needed to better understand the interaction between multiple angling events and recovery from these events at various water temperatures, and the biological basis for sex-specific differences in cardiac function and response to challenges. This study contributes to a growing body of evidence on the effects of repeated stressors on wild fish.

High egg retention in Chinook Salmon Oncorhynchus tshawytscha carcasses sampled downstream of a migratory barrier.

Barriers in rivers have the potential to severely decrease functional connectivity between habitats. Failure to pass barriers and reach natal spawning habitat may compromise individual reproductive success, particularly for semelparous, philopatric species that rely on free-flowing rivers to reach natal habitat during their once-in-a-lifetime spawning migrations. To investigate the consequences of in-river barriers on fish spawning success, we quantified egg retention and spawning effort (caudal fin wear) in female Chinook Salmon Oncorhynchus tshawytscha carcasses collected downstream of the Whitehorse Hydro Plant on the upper Yukon River and at a nearby free-flowing tributary (Teslin River) from 2018 to 2020 (~2900 km migrations). Previous studies have demonstrated that a large proportion of fish attempting to reach spawning locations upstream of the hydro plant fail to pass the associated fishway. We estimated nearly all female salmon failing to pass the hydro plant attempted spawning in non-natal habitat downstream, but that these females retained ~34% of their total fecundity compared to ~6% in females from the free-flowing river. Females downstream of the hydro plant also had lower wear on their caudal fin, a characteristic that was correlated with increased egg deposition. Egg retention did not vary across years with different run sizes, and we propose that egg retention downstream of the hydro plant was not driven by density-dependent mechanisms. Findings from this work indicate that female Chinook Salmon can still deposit eggs following failed fish passage and failure to reach natal spawning sites, though egg retention rates are considerably higher and uncertainties remain about reproductive success. We encourage researchers to incorporate carcass surveys into fish passage evaluations for semelparous species to fully account for consequences of failed passage.

The movement ecology of fishes.

Movement of fishes in the aquatic realm is fundamental to their ecology and survival. Movement can be driven by a variety of biological, physiological and environmental factors occurring across all spatial and temporal scales. The intrinsic capacity of movement to impact fish individually (e.g., foraging) with potential knock-on effects throughout the ecosystem (e.g., food web dynamics) has garnered considerable interest in the field of movement ecology. The advancement of technology in recent decades, in combination with ever-growing threats to freshwater and marine systems, has further spurred empirical research and theoretical considerations. Given the rapid expansion within the field of movement ecology and its significant role in informing management and conservation efforts, a contemporary and multidisciplinary review about the various components influencing movement is outstanding. Using an established conceptual framework for movement ecology as a guide (i.e., Nathan et al., 2008: 19052), we synthesized the environmental and individual factors that affect the movement of fishes. Specifically, internal (e.g., energy acquisition, endocrinology, and homeostasis) and external (biotic and abiotic) environmental elements are discussed, as well as the different processes that influence individual-level (or population) decisions, such as navigation cues, motion capacity, propagation characteristics and group behaviours. In addition to environmental drivers and individual movement factors, we also explored how associated strategies help survival by optimizing physiological and other biological states. Next, we identified how movement ecology is increasingly being incorporated into management and conservation by highlighting the inherent benefits that spatio-temporal fish behaviour imbues into policy, regulatory, and remediation planning. Finally, we considered the future of movement ecology by evaluating ongoing technological innovations and both the challenges and opportunities that these advancements create for scientists and managers. As aquatic ecosystems continue to face alarming climate (and other human-driven) issues that impact animal movements, the comprehensive and multidisciplinary assessment of movement ecology will be instrumental in developing plans to guide research and promote sustainability measures for aquatic resources.

Collaboration between fish passage scientists and engineers: Insights from an international questionnaire.

Fish passage science and practice seeks to facilitate the movement of fish around obstacles in their habitat, primarily through the construction of fishways and culverts. Successful implementation of fish passage requires collaboration between groups with very different backgrounds and expertise, including knowledge-producers (scientists who study fish passage and related topics such as fish swimming ability) and knowledge users (engineers who apply that knowledge to design fish passage solutions). To investigate the nature of collaboration between these groups, we surveyed fish passage scientists and engineers from around the world. Respondents were asked about the importance of collaboration, mechanisms of collaboration, potential barriers to collaboration, and how collaboration can be improved. Both fish passage scientists and engineers reported high importance of collaboration and that they collaborated frequently with the other group. Respondents reported that consultation with other professionals (of their discipline and the other) was the most important means of obtaining and sharing information related to fish passage science and engineering. Both groups also tended to over-estimate their knowledge and use of the other's discipline. While respondents reported high engagement in collaboration, key themes emerged with respect to barriers to collaboration and means of improving collaboration. These included lacking a shared understanding of both disciplines, professional differences, insufficient institutional support, and inadequate sharing of knowledge (e.g., reporting and publishing). Opportunities for improving collaboration identified by respondents included 1) more interdisciplinary opportunities that facilitate interaction (particularly conferences and workshops); 2) promoting collaborative projects and interactions between fish passage scientists and engineers on project teams; and 3) ensuring that information is shared between groups (e.g., through accessible publications). Findings from this research have the potential to enhance collaboration between scientists and engineers, to the benefit of fish passage and fish populations.

Sentiment analysis as a measure of conservation culture in scientific literature.

Culturomics is emerging as an important field within science, as a way to measure attitudes and beliefs and their dynamics across time and space via quantitative analysis of digitized data from literature, news, film, social media, and more. Sentiment analysis is a culturomics tool that, within the last decade, has provided a means to quantify the polarity of attitudes expressed within various media. Conservation science is a crisis discipline; therefore, accurate and effective communication are paramount. We investigated how conservation scientists communicate their findings through scientific journal articles. We analyzed 15,001 abstracts from articles published from 1998 to 2017 in 6 conservation-focused journals selected based on indexing in scientific databases. Articles were categorized by year, focal taxa, and the conservation status of the focal species. We calculated mean sentiment score for each abstract (mean adjusted z score) based on 4 lexicons (Jockers-Rinker, National Research Council, Bing, and AFINN). We found a significant positive annual trend in the sentiment scores of articles. We also observed a significant trend toward increasing negativity along the spectrum of conservation status categories (i.e., from least concern to extinct). There were some clear differences in the sentiments with which research on different taxa was reported, however. For example, abstracts mentioning lobe finned fishes tended to have high sentiment scores, which could be related to the rediscovery of the coelacanth driving a positive narrative. Contrastingly, abstracts mentioning elasmobranchs had low scores, possibly reflecting the negative sentiment score associated with the word shark. Sentiment analysis has applications in science, especially as it pertains to conservation psychology, and we suggest a new science-based lexicon be developed specifically for the field of conservation.

El Análisis de Opinión como Medida de la Cultura de Conservación en la Literatura Científica Lennox et al. Resumen La culturomía está emergiendo como un campo importante dentro de la ciencia pues es una manera de medir las actitudes, creencias y sus dinámicas a través del tiempo y el espacio por medio de un análisis cuantitativo de datos digitalizados a partir de la literatura, las noticias, las películas, las redes sociales y otros medios. El análisis de opinión es una herramienta de la culturomía que, en la última década, ha proporcionado los medios para cuantificar la polaridad de las actitudes expresadas en varios medios. La ciencia de la conservación es una disciplina de crisis; por lo tanto, la comunicación certera y efectiva es de suma importancia. Investigamos cómo los científicos de la conservación comunican sus hallazgos por medio de los artículos en las revistas científicas. Analizamos 15,001 resúmenes de artículos publicados entre 1998 y 2017 en seis revistas enfocadas en la conservación que fueron seleccionados con base en los índices de las bases de datos científicos. Categorizamos los artículos por año, taxón de enfoque y el estado de conservación de la especie focal. Calculamos la opinión promedio para cada resumen (puntaje z ajustado a la media) con base en cuatro lexicones (Jockers-Rinker, National Research Council, Bing y AFINN). Encontramos una significativa tendencia positiva anual en los puntajes de opinión de los artículos. También observamos una tendencia significativa hacia el incremento en la negatividad a lo largo del espectro de categorías de estado de conservación (es decir, de aquellas de menos preocupación a aquellas en peligro crítico o extintas). Sin embargo, hubo algunas diferencias claras en las opiniones con las cuales se reportaron las investigaciones sobre los diferentes taxones. Por ejemplo, los resúmenes que mencionaron a los peces de aletas lobuladas tendieron hacia los puntajes altos de opinión, lo que podría relacionarse con el redescubrimiento del celacanto como causa de una narrativa positiva. En contraste, los resúmenes que mencionaron a los elasmobranquios tuvieron puntajes bajos, lo que refleja el puntaje de opinión negativa asociado con la palabra tiburón. El análisis de opinión tiene aplicaciones en la ciencia, especialmente como parte de la psicología de la conservación, y sugerimos que se desarrolle un nuevo lexicón basado en la ciencia específicamente para el campo de la conservación.

Searching for responsible and sustainable recreational fisheries in the Anthropocene.

Recreational fisheries that use rod and reel (i.e., angling) operate around the globe in diverse freshwater and marine habitats, targeting many different gamefish species and engaging at least 220 million participants. The motivations for fishing vary extensively; whether anglers engage in catch-and-release or are harvest-oriented, there is strong potential for recreational fisheries to be conducted in a manner that is both responsible and sustainable. There are many examples of recreational fisheries that are well-managed where anglers, the angling industry and managers engage in responsible behaviours that both contribute to long-term sustainability of fish populations and the sector. Yet, recreational fisheries do not operate in a vacuum; fish populations face threats and stressors including harvest from other sectors as well as environmental change, a defining characteristic of the Anthropocene. We argue that the future of recreational fisheries and indeed many wild fish populations and aquatic ecosystems depends on having responsible and sustainable (R&S) recreational fisheries whilst, where possible, addressing, or at least lobbying for increased awareness about the threats to recreational fisheries emanating from outside the sector (e.g., climate change). Here, we first consider how the concepts of R&S intersect in the recreational fishing sector in an increasingly complex socio-cultural context. Next, we explore the role of the angler, angling industry and decision-makers in achieving R&S fisheries. We extend this idea further by considering the consequences of a future without recreational fisheries (either because of failures related to R&S) and explore a pertinent case study situated in Uttarakahand, India. Unlike other fisheries sectors where the number of participants is relatively small, recreational angling participants are numerous and widespread, such that if their actions are responsible, they have the potential to be a key voice for conservation and serve as a major force for good in the Anthropocene. What remains to be seen is whether this will be achieved, or if failure will occur to the point that recreational fisheries face increasing pressure to cease, as a result of external environmental threats, the environmental effects of recreational fishing and emerging ethical concerns about the welfare of angled fish.

Angling into the Future: Ten Commandments for Recreational Fisheries Science, Management, and Stewardship in a Good Anthropocene.

A new geological epoch, the "Anthropocene", has been defined as the period in which humans have had substantial geological and ecological influence on the planet. A positive future for this epoch can be referred to as the "good Anthropocene" and would involve effective management strategies and changes in human behavior that promote the sustainability and restoration of ecosystems. Recreational fisheries hold significant social, cultural, and economic value and can generate many benefits when managed sustainably and thus be an integral part of a "good Anthropocene". Here, we list ten commandments to facilitate persistence and long-term sustainability of recreational fisheries in the "good Anthropocene". This list includes fostering aquatic stewardship, promoting education, using appropriate capture gear, adopting evidence-based management approaches, promoting the concept of resilience, obtaining and using effort data in management, embracing the ecosystem approach, engaging in multilevel collaboration, enhancing accessibility, and embracing optimism. When used singly, or simultaneously, these ten commandments will contribute to the harmonization of sustainable fish populations and angling practices, to create recreational fisheries' "bright spots".

Technological innovations in the recreational fishing sector: implications for fisheries management and policy.

Technology that is developed for or adopted by the recreational fisheries sector (e.g., anglers and the recreational fishing industry) has led to rapid and dramatic changes in how recreational anglers interact with fisheries resources. From improvements in finding and catching fish to emulating their natural prey and accessing previously inaccessible waters, to anglers sharing their exploits with others, technology is completely changing all aspects of recreational fishing. These innovations would superficially be viewed as positive from the perspective of the angler (aside from the financial cost of purchasing some technologies), yet for the fisheries manager and policy maker, technology may create unintended challenges that lead to reactionary or even ill-defined approaches as they attempt to keep up with these changes. The goal of this paper is to consider how innovations in recreational fishing are changing the way that anglers interact with fish, and thus how recreational fisheries management is undertaken. We use a combination of structured reviews and expert analyses combined with descriptive case studies to highlight the many ways that technology is influencing recreational fishing practice, and, relatedly, what it means for changing how fisheries and/or these technologies need to be managed-from changes in fish capture, to fish handling, to how anglers share information with each other and with managers. Given that technology is continually evolving, we hope that the examples provided here lead to more and better monitoring of technological innovations and engagement by the management and policy authorities with the recreational fishing sector. Doing so will ensure that management actions related to emerging and evolving recreational fishing technology are more proactive than reactive.