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1.
Environ Manage ; 73(3): 668-682, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38019304

RESUMO

Research funders and managers can play a critical role in supporting the translation of knowledge into action by facilitating the brokering of knowledge and partnerships. We use semi-structured interviews with a research funding agency, the Australian Centre for International Agricultural Research (ACIAR), to explore (i) ways that funders can facilitate knowledge brokering, the (ii) barriers to, and (iii) enablers for, facilitating knowledge brokering, and (iv) the individual skills and attributes for research program funders and managers to be effective brokers. Based on these findings, we generate three considerations for research funders elsewhere, in particular R4D funders, seeking to build capacity for knowledge brokering: (i) formalise the process and practice, (ii) develop shared language and understanding, and (iii) build individual competencies and capabilities. Our findings complement the existing literature with a context specific analysis of how research funders can facilitate knowledge brokering, and by identifying the barriers and enablers in doing so.


Assuntos
Conhecimento , Pesquisa Translacional Biomédica , Austrália
2.
Environ Manage ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834791

RESUMO

Recreational angling of nesting largemouth bass (Micropterus nigricans) and smallmouth bass (M. dolomieu) can greatly increase nest abandonment, and in the northern clines of their range, decrease recruitment. This is the case in eastern Ontario, where high levels of non-compliance and difficult to enforce regulations have impacted black bass (Micropterus spp.) conservation and management. Effective January 1, 2024 until December 31st, 2025, novel and experimental fishing sanctuaries were imposed on portions of Charleston Lake and Opinicon Lake that prohibit recreational fishing of all types from April 15th to the Friday before the first Saturday in July (encompassing the full bass reproductive season). As part of the formal process to institute these experimental regulations, public comments were collected on the Environmental Registry of Ontario. We examined those comments and identified supportive and non-supportive themes related to these experimental regulations. While a majority of stakeholders were in support of the new regulations, we also noted sub-themes that may hinder regulation acceptance. Those sub-themes include: a perceived lack of enforcement negating the potential benefits of the sanctuaries, under-estimation of the extent of non-compliance with existing regulations such that new regulations are unnecessary, misunderstanding and misinformation, as well as distrust of government and the academic research community. Understanding and addressing these stakeholder perspectives will help researchers studying the new sanctuary areas and managers understand any lack of compliance while informing future decisions about bass management in eastern Ontario and beyond.

3.
J Environ Manage ; 330: 117140, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603252

RESUMO

Natural resource governance is inherently complex owing to the socio-ecological systems in which it is embedded. Working arrangements have been fundamentally transformed throughout the COVID-19 pandemic with potential negative impacts on trust-based social networks foundational to resource management and transboundary governance. To inform development of a post-pandemic new-normal in resource management, we examined trust relationships using the Laurentian Great Lakes of North America as a case study. 82.9% (n = 97/117) of Great Lakes fishery managers and scientists surveyed indicated that virtual engagement was effective for maintaining well-established relationships during the pandemic; however, 76.7% (n = 89/116) of respondents indicated in-person engagement to be more effective than virtual engagement for building and maintaining trust. Despite some shortcomings, virtual or remote engagement presents opportunities, such as: (1) care and nurturing of well-established long-term relationships; (2) short-term (1-3 years) trust maintenance; (3) peer-peer or mentor-mentee coordination; (4) supplemental communications; (5) producer-push knowledge dissemination; and, if done thoughtfully, (6) enhancing diversity, equity, and inclusion. Without change, pre-pandemic trust-based relationships foundational to cooperative, multinational, resource management are under threat.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Confiança , Recursos Naturais , Conservação dos Recursos Naturais
4.
J Environ Manage ; 289: 112366, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33848883

RESUMO

Pro-environmental behaviours (PEBs) are important for mitigation and restoration efforts in the Anthropocene. As recreationists are motivated to engage in leisure activities to increase their own personal wellbeing, we submit that threats to wellbeing (an egocentric motivator) predict engagement in PEBs amongst recreationists. We also predict that differences in experiences across groups of recreationists leads to differences in PEB engagement. Using an online survey, we test our two hypotheses (if recreationists perceive there is a threat to their wellbeing and that their behaviours can yield environmental successes, then they will be more likely to engage in PEBs, and if recreationists differ in recreational experiences then they will demonstrate differences in PEB engagement) amongst outdoor recreationists, specifically Canadian rainbow trout and steelhead anglers in British Columbia (n = 894 respondents). We define 'threat to wellbeing' as the interaction of environmental threat-perceptions of used environments for fishing, and level of centrality fishing has to one's lifestyle. To test our first hypothesis, we conducted three linear regressions corresponding to three different PEBs related to catch-and-release (C&R) fishing. Our egocentric predictor 'threat to wellbeing' was only significant for one out of the three PEBs tested, showing mixed support for our first hypothesis. It is of note that 'environmental threat perceptions' and one's belief in successes resulting from PEB engagement were found to be significant predictors for all three PEBs tested. These results suggest that predictors of PEB may not always be transferable across PEBs relating to recreational activities, and environmental threat perception and one's belief in successes resulting from PEB engagement are strong predictors of PEBs amongst recreationists. To test our second hypothesis, we conducted a Kruskal Wallis test to determine if there were significant differences across angler groups in PEB predictor scores and PEB engagement and conducted pairwise population Z-tests to determine proportional participation rates across angler groups for the three PEBs and PEB predictors investigated. Experiences were found to shape predictors of PEBs, as well as likelihood to engage in PEBs, as different angler groups targeting different fish (i.e., rainbow trout vs steelhead) and using different aquatic habitats (i.e., rivers vs. lakes) demonstrated significantly different scores for PEB predictors, as well as significantly different likelihood to engage in two of the three PEBs tested. These findings support the notion that recreationists are not a homogenous group, and that their beliefs and resulting behaviours during recreational activities are determined by their experiences in nature and can be influenced by the species with which they interact, and the habitats they use for recreation.


Assuntos
Pesqueiros , Recreação , Animais , Colúmbia Britânica , Conservação dos Recursos Naturais , Ecossistema , Lagos
5.
Fish Res ; 240: 105961, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36540896

RESUMO

The COVID-19 pandemic and corresponding public health mitigation strategies have altered many facets of human life. And yet, little is known about how public health measures have impacted complex socio-ecological systems such as recreational fisheries. Using an online snowball survey, we targeted resident anglers in Ontario, Canada, to obtain preliminary insights on how the pandemic has impacted recreational fishing and related activity. We also explored angler perspectives on pandemic-related restrictions and other aspects of fisheries management. Our results point to the value of recreational fisheries for the mental and physical well-being of participants, as well as the value and popularity of outdoor recreation during a pandemic. Although angling effort and fish consumption appeared to decline during the early phases of the pandemic, approximately 21 % of the anglers who responded to our survey self-identified as new entrants who had begun or resumed fishing in that time. Self-reported motivations to fish during the pandemic suggest that free time, importance to mental and physical health, and desires for self-sufficiency caused some anglers to fish more, whereas a lack of free time, poor or uncertain accessibility, and perceived risks caused some anglers to fish less. Respondents also expressed their desires for more clear and consistent communication about COVID-19 fishing restrictions from governments, and viewed angling as a safe pandemic activity. Information on recreational angler behaviours, motivations, and perspectives during the pandemic may prove valuable to fisheries managers and policy makers looking to optimize their strategies for confronting this and other similar crises.

6.
J Exp Biol ; 223(Pt 14)2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32561626

RESUMO

Female-biased mortality has been repeatedly reported in Pacific salmon during their upriver migration in both field studies and laboratory holding experiments, especially in the presence of multiple environmental stressors, including thermal stress. Here, we used coho salmon (Oncorhynchus kisutch) to test whether females exposed to elevated water temperatures (18°C) (i) suppress circulating sex hormones (testosterone, 11-ketotestosterone and estradiol), owing to elevated cortisol levels, (ii) have higher activities of enzymes supporting anaerobic metabolism (e.g. lactate dehydrogenase, LDH), (iii) have lower activities of enzymes driving oxidative metabolism (e.g. citrate synthase, CS) in skeletal and cardiac muscle, and (iv) have more oxidative stress damage and reduced capacity for antioxidant defense [lower catalase (CAT) activity]. We found no evidence that a higher susceptibility to oxidative stress contributes to female-biased mortality at warm temperatures. We did, however, find that females had significantly lower cardiac LDH and that 18°C significantly reduced plasma levels of testosterone and estradiol, especially in females. We also found that relative gonad size was significantly lower in the 18°C treatment regardless of sex, whereas relative liver size was significantly lower in females held at 18°C. Further, relative spleen size was significantly elevated in the 18°C treatments across both sexes, with larger warm-induced increases in females. Our results suggest that males may better tolerate bouts of cardiac hypoxia at high temperature, and that thermal stress may also disrupt testosterone- and estradiol-mediated protein catabolism, and the immune response (larger spleens), in migratory female salmon.


Assuntos
Lactato Desidrogenases , Oncorhynchus kisutch , Salmão , Animais , Estradiol , Feminino , Hormônios Esteroides Gonadais , Masculino , Salmão/fisiologia
7.
J Fish Biol ; 92(1): 229-236, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29194613

RESUMO

This study demonstrates that vegetable shortening and cocoa butter are two effective vehicles for intraperitoneal cortisol implants in juvenile teleosts, specifically brown trout Salmo trutta, residing in north temperate freshwater environments. Each vehicle showed a different pattern of cortisol elevation. Vegetable shortening was found to be a more suitable vehicle for long-term cortisol elevation [elevated at 3, 6 and 9 days post treatment (dpt)], while cocoa butter may be better suited for short-term cortisol elevation (only elevated at 3 dpt). Additionally, plasma cortisol levels were higher with cortisol-vegetable shortening than with cortisol-cocoa butter implants. Plasma glucose levels were elevated 6 and 9 dpt for fishes injected with cortisol-vegetable shortening, but did not change relative to controls and shams in cortisol-cocoa butter fishes. In conclusion, vegetable shortening and cocoa butter are both viable techniques for cortisol manipulation in fishes in temperate climates, providing researchers with different options depending on study objectives.


Assuntos
Gorduras na Dieta , Hidrocortisona/farmacologia , Bombas de Infusão Implantáveis , Animais , Glicemia , Truta/sangue , Truta/metabolismo
8.
Ecology ; 98(3): 608-615, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27984657

RESUMO

Despite many similarities and intuitive links between individual dietary specialization and behavioral inter-individual variation, these phenomena have been studied in isolation, and empirical data confirming relationships between these intraspecific variance sources are lacking. Here we use stable isotope analysis and acoustic telemetry to test the hypothesis that individual specialization in trophic (δ15 N) and littoral/pelagic prey reliance (δ13 C) covary with inter-individual variation in movement in a group of 34 free-swimming burbot (Lota lota). By performing stable isotope analysis on tissues with differing isotopic turnover rates (anal fin and dorsal muscle), in 24 lethally sampled burbot, we demonstrate that individual specialization in trophic niche (δ15 N) and littoral/pelagic prey reliance (δ13 C) occurred within the population. By performing stable isotope analysis on anal fins of a group of telemetry tagged burbot, we were able to show that interactions between trophic niche and littoral/pelagic prey reliance, explained a significant proportion of the subsequent between-individual variance in mean movement rates. These findings demonstrate an empirical connection between behavioral inter-individual variation and dietary specialization, thus providing a substantial expansion of our understanding of the wider ecological consequences of these interesting phenomena.


Assuntos
Dieta/estatística & dados numéricos , Peixes/fisiologia , Animais , Ecologia , Comportamento Alimentar , Água Doce , Isótopos de Nitrogênio , Comportamento Predatório
9.
Environ Manage ; 60(6): 1139-1154, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28939998

RESUMO

Freshwater ecosystems provide many ecosystem services; however, they are often degraded as a result of human activity. To address ecosystem degradation in the Laurentian Great Lakes, Canada and the United States of America established the Great Lakes Water Quality Agreement (GLWQA). In 1987, 43 highly polluted and impacted areas were identified under the GLWQA as having one or more of 14 Beneficial Use Impairments (BUIs) to the physical and chemical habitat for fish, wildlife and humans, and were designated as Areas of Concern (AOC). Subnational jurisdictions combined with local stakeholders, with support from federal governments, developed plans to remediate and restore these sites. Biotelemetry (the tracking of animals using electronic tags) provides information on the spatial ecology of fish in the wild relevant to habitat management and stock assessment. Here, seven case studies are presented where biotelemetry data were directly incorporated within the AOC Remedial Action Plan (RAP) process. Specific applications include determining seasonal fish-habitat associations to inform habitat restoration plans, identifying the distribution of pollutant-indicator species to identify exposure risk to contamination sources, informing the development of fish passage facilities to enable fish to access fragmented upstream habitats, and assessing fish use of created or restored habitats. With growing capacity for fish biotelemetry research in the Great Lakes, we discuss the strengths and weaknesses of incorporating biotelemetry into AOC RAP processes to improve the science and practice of restoration and to facilitate the delisting of AOCs.


Assuntos
Conservação dos Recursos Hídricos/métodos , Monitoramento Ambiental/métodos , Peixes/crescimento & desenvolvimento , Lagos/química , Telemetria , Poluição da Água/análise , Animais , Canadá , Ecossistema , Humanos , Qualidade da Água
10.
J Exp Biol ; 219(Pt 8): 1237-48, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-26896551

RESUMO

Parental care is an essential life-history component of reproduction for many animal species, and it entails a suite of behavioural and physiological investments to enhance offspring survival. These investments can incur costs to the parent, reducing their energetic and physiological condition, future reproductive capabilities and survival. In fishes, relatively few studies have focused on how these physiological costs are mediated. Male smallmouth bass provide parental care for developing offspring until the brood reaches independence. During this energetically demanding life stage, males cease active foraging as they vigorously defend their offspring. Experimental manipulation of cortisol levels (via implantation) and food (via supplemental feeding) in parental males was used to investigate the fitness consequences of parental care. Improving the nutritional condition of nest-guarding males increased their reproductive success by reducing premature nest abandonment. However, supplemental feeding and cortisol treatment had no effect on parental care behaviours. Cortisol treatment reduced plasma lymphocyte numbers, but increased neutrophil and monocyte concentrations, indicating a shift in immune function. Supplemental feeding improved the physiological condition of parental fish by reducing the accumulation of oxidative injury. Specifically, supplemental feeding reduced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) on DNA nucleotides. Increasing the nutritional condition of parental fish can reduce the physiological cost associated with intensive parental activity and improve overall reproductive success, illustrating the importance of nutritional condition as a key modulator of parental fitness.


Assuntos
Bass/sangue , Bass/fisiologia , Comportamento Animal , Comportamento Alimentar , Hidrocortisona/sangue , Estado Nutricional , Estresse Psicológico/fisiopatologia , 8-Hidroxi-2'-Desoxiguanosina , Animais , Bass/imunologia , Glicemia/metabolismo , Cloretos/sangue , Colesterol/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Lagos , Leucócitos/metabolismo , Magnésio/sangue , Masculino , Ontário , Estresse Oxidativo , Estresse Psicológico/sangue
11.
J Fish Biol ; 88(6): 2111-29, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27125426

RESUMO

In this study, animal-borne telemetry with temperature sensors was coupled with extensive habitat temperature monitoring in a dimictic reservoir, to test the following hypotheses: behavioural thermoregulation occurs throughout the year and temperature selection varies on a diel and seasonal basis, in a winter-specialist diel-migrating fish. Burbot Lota lota demonstrated nightly behavioural thermoregulation throughout the year, with a large seasonal shift between selection for very cold temperatures (<2° C) optimal for reproduction during the spawning period and selection for warmer temperatures (12-14° C) optimal for hunting and feeding during non-reproductive periods. During daylight hours, while L. lota avoided habitats warmer than optimal for reproduction and feeding during the spawning and non-reproductive periods, respectively, active selection was limited to selection for 4-6° C habitat during the prespawning period. Although behavioural thermoregulation explained the night-time migration, behavioural thermoregulation only partially explained daytime behaviour, indicating that diel migration is best explained by a combination of factors. Thus, thermal-habitat selection was a good predictor of night-time habitat occupancy in a diel-migrating species. Together, these results show that thermal-habitat selection by fishes may be important throughout the year and a more seasonally plastic behaviour than previously recognized.


Assuntos
Migração Animal , Ecossistema , Gadiformes/fisiologia , Animais , Comportamento Animal , Temperatura Baixa , Reprodução , Estações do Ano , Comportamento Sexual Animal , Temperatura
12.
Conserv Biol ; 29(4): 1065-1075, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25833384

RESUMO

Electronic tags (both biotelemetry and biologging platforms) have informed conservation and resource management policy and practice by providing vital information on the spatial ecology of animals and their environments. However, the extent of the contribution of biological sensors (within electronic tags) that measure an animal's state (e.g., heart rate, body temperature, and details of locomotion and energetics) is less clear. A literature review revealed that, despite a growing number of commercially available state sensor tags and enormous application potential for such devices in animal biology, there are relatively few examples of their application to conservation. Existing applications fell under 4 main themes: quantifying disturbance (e.g., ecotourism, vehicular and aircraft traffic), examining the effects of environmental change (e.g., climate change), understanding the consequences of habitat use and selection, and estimating energy expenditure. We also identified several other ways in which sensor tags could benefit conservation, such as determining the potential efficacy of management interventions. With increasing sensor diversity of commercially available platforms, less invasive attachment techniques, smaller device sizes, and more researchers embracing such technology, we suggest that biological sensor tags be considered a part of the necessary toolbox for conservation. This approach can measure (in real time) the state of free-ranging animals and thus provide managers with objective, timely, relevant, and accurate data to inform policy and decision making.


El Uso de Etiquetas de Sensor Biológico en la Conservación de Animales Resumen Las etiquetas electrónicas (plataformas tanto de bio-telemetría como de bio-registro) han informado a la conservación y a la política y práctica del manejo de recursos al proporcionar información vital sobre la ecología espacial de los animales y su ambiente. Sin embargo, la extensión de la contribución de los sensores biológicos (dentro de las etiquetas electrónicas) que miden el estado de un animal (p. ej.: ritmo cardíaco, temperatura corporal y detalles sobre el movimiento y la energética) es menos evidente. Una revisión de la literatura reveló que, a pesar de un número creciente de etiquetas sensoriales de estado disponibles comercialmente y un enorme potencial de aplicación de dichos dispositivos en la biología animal, hay pocos ejemplos de su aplicación en la conservación. Las aplicaciones existentes se rigieron por cuatro temas principales: cuantificar la perturbación (p. ej.: vehicular, de tráfico aéreo o de ecoturismo), examinar los efectos del cambio ambiental (p. ej.: cambio climático), entender las consecuencias de la selección y uso de hábitat, y estimar el gasto energético. También identificamos muchas otras maneras en que las etiquetas sensoriales podrían beneficiar a la conservación, como determinar la efectividad potencial de las intervenciones de manejo. Con el incremento en la diversidad de sensores en plataformas disponibles comercialmente, técnicas menos invasivas de etiquetado, tamaños más pequeños de los dispositivos, y más investigadores adoptando dicha tecnología, sugerimos que las etiquetas de sensor biológico se consideren como una parte de la caja de herramientas necesaria para la conservación. Esta estrategia puede medir (en tiempo real) el estado de animales libres y así proporcionar a los manejadores datos objetivos, oportunos, relevantes y precisos para informar la toma de decisiones y la política.


Assuntos
Conservação dos Recursos Naturais/métodos , Tecnologia de Sensoriamento Remoto/métodos , Migração Animal , Animais , Ecossistema , Movimento
13.
J Therm Biol ; 47: 63-74, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25526656

RESUMO

Anthropogenic climate change is altering temperature regimes for coastal marine fishes. However, given that temperature changes will not occur in isolation of other stressors, it is necessary to explore the potential consequences of stress on the thermal tolerances and preferences of tropical marine fish in order to understand the thresholds for survival, and predict the associated coastal ecological consequences. In this study, we used exogenous cortisol injections to investigate the effects of a thermal challenge on checkered puffers (Sphoeroides testudineus) as a secondary stressor. There were no significant differences between control and cortisol-treated fish 48h following cortisol treatment for swimming ability (using a chase to exhaustion protocol), blood glucose concentrations or standard metabolic rate. In the lab, control and cortisol-treated puffers were exposed to ambient (29.1±1.5°C), ambient +5°C (heat shock) and ambient -5°C (cold shock) for 4h and to evaluate the consequences of abrupt temperature change on puff performance and blood physiology. Following cold shock, control fish exhibited increases in cortisol levels and weak 'puff' performance. Conversely, fish dosed with cortisol exhibited consistently high cortisol levels independent of thermal treatment, although there was a trend for an attenuated cortisol response in the cortisol-treated fish to the cold shock treatment. A 20-day complementary field study conducted in the puffer's natural habitat, a tidal creek in Eleuthera, The Bahamas, revealed that cortisol-injected fish selected significantly cooler temperatures, measured using accumulated thermal units, when compared to controls. These results, and particularly the discrepancies between consequences documented in the laboratory and the ecological trends observed in the field, highlight the need to establish the link between laboratory and field data to successfully develop management policies and conservation initiatives with regards to anthropogenic climate change.


Assuntos
Resposta ao Choque Frio/efeitos dos fármacos , Resposta ao Choque Térmico/efeitos dos fármacos , Hidrocortisona/farmacologia , Tetraodontiformes/fisiologia , Animais , Bahamas , Glicemia , Natação , Temperatura , Tetraodontiformes/metabolismo
14.
J Fish Biol ; 87(2): 342-59, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26179562

RESUMO

In this study, behaviour and survival following catch-and-release (C&R) angling was investigated in wild Atlantic salmon Salmo salar (n = 75) angled on sport fishing gear in the River Otra in southern Norway at water temperatures of 16.3-21.1 °C. Salmo salar were tagged externally with radio transmitters and immediately released back into the river to simulate a realistic C&R situation. The majority of S. salar (91%) survived C&R. Most S. salar that were present in the River Otra during the spawning period 3-4 months later were located at known spawning grounds. Downstream movements (median furthest position: 0.5 km, range: 0.1-11.0 km) during the first 4 days after release were recorded for 72% of S. salar, presumably stress-induced fallback associated with C&R. Individuals that fell back spent a median of 15 days before commencing their first upstream movement after release, and 34 days before they returned to or were located above their release site. Mortality appeared to be somewhat elevated at the higher end of the temperature range (14% at 18-21 °C), although sample sizes were low. In conclusion, C&R at water temperatures up to 18 °C had small behavioural consequences and was associated with low mortality (7%). Nevertheless, low levels of mortality occur due to C&R angling and these losses should be accounted for by management authorities in rivers where C&R is practised. Refinement of best practices for C&R may help to reduce mortality, particularly at warmer temperatures.


Assuntos
Migração Animal , Salmo salar/fisiologia , Animais , Conservação dos Recursos Naturais , Atividades Humanas , Noruega , Rios , Temperatura
15.
J Environ Manage ; 164: 67-73, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26342269

RESUMO

Excessive sedimentation derived from anthropogenic activities is a main factor in habitat and biodiversity loss in freshwater ecosystems. To prevent offsite movement of soil particles, many environmental regulatory agencies mandate the use of perimeter silt fences. However, research regarding the efficiency of these devices in applied settings is lacking, and fences are often ineffective due to poor installation and maintenance. Here, we provide an overview of the current state of research regarding silt fences, address the current culture surrounding silt fence installation and maintenance, and provide several recommendations for improving the knowledge base related to silt fence effectiveness. It is clear that there is a need for integrated long-term (i.e., extending from prior to fence installation to well after fence removal) multi-disciplinary research with appropriate controls that evaluates the effectiveness of silt control fences. Through laboratory experiments, in silico modelling and field studies there are many factors that can be experimentally manipulated such as soil types (and sediment feed rate), precipitation regimes (and flow rate), season, slope, level of site disturbance, fence installation method, type of fence material, depth of toe, type and spacing of support structures, time since installation, level of inspection and maintenance, among others, that all require systematic evaluation. Doing so will inform the practice, as well as identify specific technical research needs, related to silt fence design and use. Moreover, what constitutes "proper" installation and maintenance is unclear, especially given regional- and site-level variation in precipitation, slope, and soil characteristics. Educating and empowering construction crews to be proactive in maintenance of silt fencing is needed given an apparent lack of compliance monitoring by regulatory agencies and the realities that the damage is almost instantaneous when silt fences fail. Our goal is not to dismiss silt fences as a potentially useful tool. Instead, we question the way they are currently being used and call for better science to determine what factors (in terms of fence design, installation and site-characteristics) influence effectiveness as well as better training for those that install, maintain and inspect such devices. We also encourage efforts to "look beyond the fence" to consider how silt fences can be combined with other sediment control strategies as part of an integrated sediment control program.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Biologia Marinha/métodos , Tecnologia/métodos , Biodiversidade , Água Doce , Humanos , Biologia Marinha/educação , Estações do Ano , Solo , Tecnologia/educação
16.
Gen Comp Endocrinol ; 204: 195-202, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24879931

RESUMO

Male smallmouth bass (Micropterus dolomieu) provide sole parental care until offspring reach independence, a period of several weeks. During the early parental care period when males are guarding fresh eggs (MG-FE), cortisol responsiveness is attenuated; the response is re-established when males reach the end of the parental care period and are guarding free-swimming fry (MG-FSF). It was hypothesized that attenuation of the cortisol response in male smallmouth bass during early parental care reflected modulation of hypothalamic-pituitary-interrenal (HPI) axis function. Male smallmouth bass were sampled at the beginning (MG-FE) and end of the parental care period (MG-FSF), before and/or 25 min after exposure to a standardized stressor consisting of 3 min of air exposure. Repeated sampling of stressed fish for analysis of plasma cortisol and adrenocorticotropic hormone (ACTH) levels was carried out. Males significantly elevated both plasma cortisol and ACTH levels when guarding free-swimming fry but not during early parental care. Control and stressed fish were terminally sampled for tissue mRNA abundance of preoptic area (POA) and hypothalamic corticotropin-releasing factor (CRF) as well as head kidney melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc). No significant differences in either hypothalamus CRF or head kidney P450scc mRNA abundance were found across parental care stages or in response to stress. However, POA CRF mRNA abundance and interrenal cell MC2R and StAR mRNA abundances failed to increase in response to stress in MG-FE. Thus, the attenuated cortisol response in males guarding fresh eggs may be explained by hypoactive HPI axis function in response to stress. The present is one of few studies, and the first teleost study, to address the mechanisms underlying resistance to stress during the reproductive/parental care period.


Assuntos
Bass/metabolismo , Hormônio Liberador da Corticotropina/sangue , Hidrocortisona/sangue , Sistema Hipotálamo-Hipofisário/metabolismo , Animais , Bass/crescimento & desenvolvimento , Rim Cefálico/metabolismo , Masculino , Área Pré-Óptica/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptor Tipo 2 de Melanocortina/genética , Receptor Tipo 2 de Melanocortina/metabolismo , Reprodução/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
J Fish Biol ; 84(4): 1240-6, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24689676

RESUMO

Movement estimates derived from sub-daily tracking of radio-tagged bull trout Salvelinus confluentus on the Columbia River, British Columbia, Canada, were used to test whether interindividual variation in behaviour was repeatable among contexts, both short- and long-term. Interindividual variation in S. confluentus behaviour was consistent across contexts. These findings emphasize the potential for telemetry as a tool in animal personality and temperament research.


Assuntos
Comportamento Animal , Locomoção , Telemetria , Truta/fisiologia , Sistemas de Identificação Animal , Animais , Colúmbia Britânica , Reprodutibilidade dos Testes , Rios
18.
Conserv Physiol ; 12(1): coae034, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38827188

RESUMO

Estimating the survival probability of animals released from fisheries can improve the overall understanding of animal biology with implications for fisheries management, conservation and animal welfare. Vitality indicators are simple visual measures of animal condition that change in response to stressors (like fisheries capture) and can be assessed to predict post-release survival. These indicators typically include immediate reflex responses which are typically combined into a score. Vitality indicators are straight-forward and non-invasive metrics that allow users to quantify how close (or far) an animal is from a normal, 'healthy' or baseline state, which in turn can be correlated with outcomes such as survival probability, given appropriate calibration. The literature on using vitality indicators to predict post-release survival of animals has grown rapidly over the past decade. We identified 136 papers that used vitality indicators in a fisheries context. These studies were primarily focused on marine and freshwater fishes, with a few examples using herptiles and crustaceans. The types of vitality indicators are diverse and sometimes taxa-specific (e.g. pinching leg of turtles, spraying water at nictitating membrane of sharks) with the most commonly used indicators being those that assess escape response or righting response given the vulnerability of animals when those reflexes are impaired. By presenting Pacific salmon fisheries as a case study, we propose a framework for using vitality indicators to predict survival across taxa and fisheries.

19.
Artigo em Inglês | MEDLINE | ID: mdl-23247092

RESUMO

This study is the first to calibrate acceleration transmitters with energy expenditure using a vertebrate model species. We quantified the relationship between acoustic accelerometer output and oxygen consumption across a range of swim speeds and water temperatures for Harrison River adult sockeye salmon (Oncorhynchus nerka). First, we verified that acceleration transmitters with a sampling frequency of 10 Hz could be used as a proxy for movement in sockeye salmon. Using a mixed effects model, we determined that tailbeat frequency and acceleration were positively correlated (p<0.0001), independent of tag ID. Acceleration (p<0.0001) was positively related to swim speed while fork length (p=0.051) was negatively related to swim speed. Oxygen consumption and accelerometer output (p<0.0001) had a positive linear relationship and were temperature dependent (p<0.0001). There were no differences in swim performance (F(2,12)=1.023, p=0.820) or oxygen consumption (F(1,12)=0.054, p=0.332) between tagged and untagged individuals. Five tagged fish were released into the Fraser River estuary and manually tracked. Of the five fish, three were successfully tracked for 1h. The above relationships were used to determine that the average swim speed was 1.25±0.03 body lengths s(-1) and cost of transport was 3.39±0.17 mg O(2) kg(-1)min(-1), averaged across the three detected fish. Acceleration transmitters can be effectively used to remotely evaluate fine-scale behavior and estimate energy consumption of adult Pacific salmon throughout their homeward spawning migration.


Assuntos
Acelerometria , Metabolismo Energético , Oncorhynchus/metabolismo , Natação , Animais , Calibragem , Feminino , Masculino , Consumo de Oxigênio , Valores de Referência , Temperatura
20.
J Fish Biol ; 82(4): 1138-58, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23557296

RESUMO

The consequences of stress on the behaviour of wild creek chub Semotilus atromaculatus outside the reproductive period were studied using a single intra-coelomic injection of cortisol, suspended in coconut butter, to experimentally raise plasma cortisol levels. Behaviour between cortisol-treated, sham-treated (injected with coconut butter) and control S. atromaculatus was compared in a mesocosm system, using a passive integrated transponder array, and in a natural stream system (excluding shams), using surgically implanted radio transmitters. While laboratory time-course studies revealed that the cortisol injection provided a physiologically relevant challenge, causing prolonged (c. 3 days) elevations of plasma cortisol similar to that achieved with a standardized chasing protocol, no differences in fine-scale movements were observed between cortisol-treated, sham-treated and control S. atromaculatus nor in the large-scale movements of cortisol-treated and control S. atromaculatus. Moreover, no differences were observed in diel activity patterns among treatments. Differential mortality, however, occurred starting 10 days after treatment where cortisol-treated S. atromaculatus exhibited nearly twice as many mortalities as shams and controls. These results suggest that, although the experimental manipulation of cortisol titres was sufficient to cause mortality in some individuals, there were compensatory mechanisms that maintained behaviours (i.e. including activity and movement) prior to death. This study is one of the first to use experimental cortisol implants outside a laboratory environment and during the non-reproductive period and yields insight into how wild animals respond to additional challenges (in this case elevated cortisol) using ecologically meaningful endpoints.


Assuntos
Cyprinidae/fisiologia , Hidrocortisona/farmacologia , Atividade Motora/efeitos dos fármacos , Estresse Fisiológico , Animais , Comportamento Animal/efeitos dos fármacos , Hidrocortisona/sangue , Rios , Telemetria
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