| 1. |
- Castagne, Paul, et al.
(författare)
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Patterns of genetic variation in native and non-native populations of European catfish Silurus glanis across Europe
- 2023
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Ingår i: Biodiversity and Conservation. - : Springer. - 0960-3115 .- 1572-9710. ; 32, s. 2127-2147
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Tidskriftsartikel (refereegranskat)abstract
- Biological invasions are a major component of global change worldwide. But paradoxically, an invasive species might also have threatened populations within its native range. Designing efficient management policies is needed to prevent and mitigate range expansions of invasive alien species (IAS) in non-native areas, while protecting them within their native range. Characterizing genetic variation patterns for IAS populations and deciphering the links between their native and introduced populations is helpful to (i) assess the genetic state of both native and non-native populations, (ii) reveal potential invasion pathways, (iii) define IAS management strategies in invaded areas, and (iv) identify native populations requiring conservation measures. The European catfish (Silurus glanis) is the largest European predatory fish. Introduced since the seventies from Eastern to Western Europe, it has colonized many waterbodies. Yet, little is known about the genetic status of non-native populations and the invasion pathways used by the species. Besides, some native populations are threatened, requiring conservation actions. Here, we describe current patterns of genetic variability of native and non-native S. glanis populations across Europe. Using microsatellite markers, we first assessed genetic variation within and between native and non-native populations. Second, we performed genetic clustering analyses to determine the genetic structure of multiple catfish populations across Europe and highlight their potential links. We revealed that native populations are more genetically diverse than non-native populations, and highlight complex introduction pathways involving several independent sources of introduction, which likely explain the invasion success of this large predatory fish across western Europe.
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| 2. |
- Cooke, Steven J., et al.
(författare)
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Searching for responsible and sustainable recreational fisheries in the Anthropocene
- 2019
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Ingår i: Journal of Fish Biology. - : John Wiley & Sons. - 0022-1112 .- 1095-8649. ; 94:6, s. 845-856
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Holder, Peter E., et al.
(författare)
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Preparing for a changing future in recreational fisheries : 100 research questions for global consideration emerging from a horizon scan
- 2020
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Ingår i: Reviews in Fish Biology and Fisheries. - : Springer Science and Business Media LLC. - 0960-3166 .- 1573-5184. ; 30:1, s. 137-151
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Forskningsöversikt (refereegranskat)abstract
- Recreational fisheries hold immense ecological, social, and economic value. The management of these fisheries is increasingly important as we move forward in the Anthropocene. Recreational fisheries managers face several challenges as fisheries often involve diverse social and ecological systems comprised of complex feedback and stakeholder motivations and needs. Here, we used a horizon scanning exercise to yield 100 research questions related to recreational fisheries science and management in the Anthropocene. Initial research questions (n = 205) were collected from recreational fisheries experts (i.e., stakeholders, managers, researchers) from various sectors (i.e., industry, government, NGOs) and geographic locations (14 countries: Australia, Brazil, Canada, Czech Republic, Germany, Italy, New Zealand, Norway, South Africa, Spain, Sweden, Switzerland, United Kingdom, USA). These questions were subsequently categorized, thematized, and refined by our authorship team, eventually yielding what we considered to be the top 100 research questions of relevance to management of recreational fisheries. The key themes include: human dimensions; bioeconomics; resource monitoring and data acquisition; governance; management-regulatory actions; management-stock and habitat enhancement; catch-and-release; impacts of recreational fisheries on populations, communities and ecosystems; threats and sustainability; and angler outreach, education and engagement. It is our intention that this comprehensive and forward-looking list will create a framework to guide future research within this field, and contribute to evidence-based recreational fisheries management and policy.
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| 4. |
- Lennox, Robert J., et al.
(författare)
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A role for lakes in revealing the nature of animal movement using high dimensional telemetry systems
- 2021
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Ingår i: Movement Ecology. - : BioMed Central. - 2051-3933. ; 9:1
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Forskningsöversikt (refereegranskat)abstract
- Movement ecology is increasingly relying on experimental approaches and hypothesis testing to reveal how, when, where, why, and which animals move. Movement of megafauna is inherently interesting but many of the fundamental questions of movement ecology can be efficiently tested in study systems with high degrees of control. Lakes can be seen as microcosms for studying ecological processes and the use of high-resolution positioning systems to triangulate exact coordinates of fish, along with sensors that relay information about depth, temperature, acceleration, predation, and more, can be used to answer some of movement ecology's most pressing questions. We describe how key questions in animal movement have been approached and how experiments can be designed to gather information about movement processes to answer questions about the physiological, genetic, and environmental drivers of movement using lakes. We submit that whole lake telemetry studies have a key role to play not only in movement ecology but more broadly in biology as key scientific arenas for knowledge advancement. New hardware for tracking aquatic animals and statistical tools for understanding the processes underlying detection data will continue to advance the potential for revealing the paradigms that govern movement and biological phenomena not just within lakes but in other realms spanning lands and oceans.
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| 5. |
- Lennox, Robert J., et al.
(författare)
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Electronic tagging and tracking aquatic animals to understand a world increasingly shaped by a changing climate and extreme weather events
- 2024
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 0706-652X .- 1205-7533. ; 81:3, s. 326-339
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Tidskriftsartikel (refereegranskat)abstract
- Despite great promise for understanding the impacts and extent of climate change and extreme weather events on aquatic animals, their species, and ecological communities, it is surprising that electronic tagging and tracking tools, like biotelemetry and biologging, have not been extensively used to understand climate change or develop and evaluate potential interventions that may help adapt to its impacts. In this review, we provide an overview of methodologies and study designs that leverage available electronic tracking tools to investigate aspects of climate change and extreme weather events in aquatic ecosystems. Key interventions to protect aquatic life from the impacts of climate change, including habitat restoration, protected areas, conservation translocations, mitigations against interactive effects of climate change, and simulation of future scenarios, can all be greatly facilitated by using electronic tagging and tracking. We anticipate that adopting animal tracking to identify phenotypes, species, or ecosystems that are vulnerable or resilient to climate change will help in applying management interventions such as fisheries management, habitat restoration, invasive species control, or enhancement measures that prevent extinction and strengthen the resilience of communities against the most damaging effects of climate change. Given the scalability and increasing accessibility of animal tracking tools for researchers, tracking individual organisms will hopefully also facilitate research into effective solutions and interventions against the most extreme and acute impacts on species, populations, and ecosystems.
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| 6. |
- Lennox, Robert J., et al.
(författare)
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Positioning aquatic animals with acoustic transmitters
- 2023
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Ingår i: Methods in Ecology and Evolution. - 2041-210X. ; 14:10, s. 2514-2530
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Forskningsöversikt (refereegranskat)abstract
- Geolocating aquatic animals with acoustic tags has been ongoing for decades, relying on the detection of acoustic signals at multiple receivers with known positions to calculate a 2D or 3D position, and ultimately recreate the path of an aquatic animal from detections at fixed stations.This method of underwater geolocation is evolving with new software and hardware options available to help investigators design studies and calculate positions using solvers based predominantly on time-difference-of-arrival and time-of-arrival.We provide an overview of the considerations necessary to implement positioning in aquatic acoustic telemetry studies, including how to design arrays of receivers, test performance, synchronize receiver clocks and calculate positions from the detection data. We additionally present some common positioning algorithms, including both the free open-source solvers and the ‘black-box’ methods provided by some manufacturers for calculating positions.This paper is the first to provide a comprehensive overview of methods and considerations for designing and implementing better positioning studies that will support users, and encourage further knowledge advances in aquatic systems.
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| 7. |
- Daedlow, Katrin, et al.
(författare)
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Explaining institutional persistence, adaptation, and transformation in East German recreational-fisheries governance after the German reunification in 1990
- 2013
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Ingår i: Ecological Economics. - : Elsevier BV. - 0921-8009 .- 1873-6106. ; 96, s. 36-50
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the capacity of a natural resource governance system to absorb a disturbance while maintaining its major structures and functions (defined as institutional resilience). Exemplified by East German recreational fisheries governance being disturbed by the German reunification, we studied why in five out of six East German states the former centralized governance system persisted while in one state a decentralized governance system was implemented. Based on resilience thinking and new institutional economics, three analytical steps were developed to assess: (1) the structure and function of the governance system, (2) the attributes of the disturbance and the reorganization process, and (3) human motivations. The centralized system persisted because leading managers wanted to preserve customary structures and functions, minimize transaction costs of change, and maintain powerful positions. This was possible because of their influential positions in the reorganization process. Our results suggest that in externally induced, fundamental, and rapid disturbances decision-makers tend to prevent transformations in their governance system. However, key managers in the sixth state faced the same disturbance but their lack of leadership and an emerging rivalry for fishing rights facilitated a transformation to decentralized governance. Thus, attributes of disturbances can be leveraged by actors' motivations in the reorganization process.
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| 8. |
- Sbragaglia, Valerio, et al.
(författare)
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Evolutionary implications of size-selective mortality on the ontogenetic development of shoal cohesion : a neurochemical approach using a zebrafish, Danio rerio, harvest selection experiment
- 2022
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer. - 0340-5443 .- 1432-0762. ; 76:12
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Tidskriftsartikel (refereegranskat)abstract
- Size-selective mortality may evolutionarily alter life-history as well as individual behavioral and physiological traits. Moreover, size-selective mortality can affect group behavioral traits, such as shoaling and collective properties (e.g., shoal cohesion), which are relevant for finding food and reducing risk of predation. Here, we present experimental evidence using selection lines of zebrafish (Danio rerio) that were exposed to positive ( large-harvested), negative (small-harvested), and random (control) size-selective mortality for five generations, followed by eight generations during which harvesting was halted to remove maternal effects and to study evolutionarily fixed outcomes. We investigated changes in shoal cohesion and turnover in monoamines in zebrafish through ontogeny. To that end, we repeatedly measured inter-individual distance in groups of eight fish and the turnovers of dopamine and serotonin in brains of fish from juvenile to the adult stage at 40-day intervals. We, firstly, found that shoal cohesion was overall consistent through ontogeny at group levels suggesting the presence of collective personality. Secondly, we found a decrease in shoal cohesion through ontogeny in the small-harvested and control lines, while the large-harvested line did not show any ontogenetic change. Thirdly, the selection lines did not differ among each other in shoal cohesion at any ontogenetic stage. Fourthly, dopamine turnover increased through ontogeny in a similar way for all lines while the serotonin turnover decreased in the large-harvested and control lines, but not in the small-harvested line. The large-harvested line also had higher serotonin turnover than controls at specific time periods. In conclusion, intensive size-selective mortality left an evolutionary legacy of asymmetric selection responses in the ontogeny of shoal cohesion and the underlying physiological mechanisms in experimentally harvested zebrafish in the laboratory. Significant statement The evolution of animal behavior can be affected by human activities both at behavioral and physiological levels, but causal evidence is scarce and mostly focusing on single life-stages. We studied whether and to what extent size-selective harvesting, a common selection pattern in fisheries, can be an evolutionary driver of the development of shoal cohesion during ontogeny. We used a multi-generation experiment with zebrafish to study cause-and-effects of opposing size-selection patterns. We quantified shoal cohesion, and serotonin and dopamine turnover in the brain. We found that shoal cohesion emerged as a collective personality trait and that behavioral and physiological responses were asymmetrical with respect to the opposing selection patterns.
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| 9. |
- Schlüter, Maja, et al.
(författare)
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Application of the SES Framework for Model-based Analysis of the Dynamics of Social-Ecological Systems
- 2014
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Ingår i: Ecology & Society. - 1708-3087. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Social-ecological systems (SES) are dynamic systems that continuously change in response to internal or external pressures. A better understanding of the interactions of the social and ecological systems that drive those dynamics is crucial for the development of sustainable management strategies. Dynamic models can serve as tools to explore social-ecological interactions; however, the complexity of the studied systems and the need to integrate knowledge, theories, and approaches from different disciplines pose considerable challenges for their development. We assess the potential of Ostrom's general SES framework (SESF) to guide a systematic and transparent process of model development in light of these difficulties. We develop a stepwise procedure for applying SESF to identify variables and their relationships relevant for an analysis of the SES. In doing so we demonstrate how the hierarchy of concepts in SESF and the identification of social-ecological processes using the newly introduced process relationships can help to unpack the system in a systematic and transparent way. We test the procedure by applying it to develop a dynamic model of decision making in the management of recreational fisheries. The added value of the common framework lies in the guidance it provides for (1) a structured approach to identifying major variables and the level of detail needed, and (2) a procedure that enhances model transparency by making explicit underlying assumptions and choices made when selecting variables and their interactions as well as the theories or empirical evidence on which they are based. Both aspects are of great relevance when dealing with the complexity of SES and integrating conceptual backgrounds from different disciplines. We discuss the advantages and difficulties of the application of SESF for model development, and contribute to its further refinement.
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| 10. |
- Stålhammar, Martin, et al.
(författare)
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The impact of catch-and-release on the foraging behaviour of pike (Esox lucius) when released alone or into groups
- 2012
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Ingår i: Fisheries Research. - : Elsevier BV. - 0165-7836 .- 1872-6763. ; 125, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- A commonly practiced method intended to reduce mortality from recreational fisheries is mandatory (e.g., small fish protected by minimum-size limits) or voluntary catch-and-release (C&R), where fish are caught with hook and line and released alive on the assumption that fish survive unharmed. C&R can, however, have both lethal and sub-lethal consequences for fish, with altered behaviour serving as a useful indicator of sub-lethal effects. We here present a mesocosm study on the short-term effects on foraging-behaviour in response to C&R in pike (Esox lucius). when being released alone or into conspecific groups. Due to the potential of cannibalistic attacks or agonistic interactions post-release, we expected that foraging behaviour would be affected by social environment at release. We found that the time to first interest in and attack on prey was significantly delayed in caught and released pike individuals, but these delays were less pronounced in pike released into groups of conspecifics. We also found that the caught and released pike expressed agonistic behaviours in comparable frequencies to unfished group conspecifics. We conclude that the short-term effects of C&R involve altered foraging behaviours, partly depending on the social context at release. Altered feeding, even if only in the short-term, may reduce body growth post-release, which may affect individual fitness and also have effects at the fish community level as a result of changes in pike predation pressure. (C) 2012 Elsevier B.V. All rights reserved.
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