Unpalatable, yet unprotected: trout reduce survival and development rate of rare toad tadpoles despite chemical defense

2017 ◽  
Vol 74 (4) ◽  
pp. 494-502 ◽  
Author(s):  
Wendy E. Lanier ◽  
Kevin R. Bestgen ◽  
W. Chris Funk ◽  
Larissa L. Bailey
Keyword(s):  
Captive Breeding ◽  
Cutthroat Trout ◽  
Negative Effects ◽  
Oncorhynchus Clarkii ◽  
Predator Prey ◽  
Survival And Development ◽  
Negative Impacts ◽  
Oncorhynchus Clarkii Stomias ◽  
Anaxyrus Boreas Boreas ◽  
Anaxyrus Boreas

Unpalatable prey species often have toxins that protect from direct consumption. However, negative effects of prey manipulation by predators are rarely considered and may understate impacts to unpalatable species. When both prey and predator are species of concern, stronger understanding of the predator–prey relationship is warranted. We explored direct and indirect effects of greenback cutthroat trout (Oncorhynchus clarkii stomias) on boreal toad (Anaxyrus boreas boreas) tadpole survival, growth, and development, as well as postmetamorphosis survival and growth. We found exposure to O. clarkii stomias delayed metamorphosis by 1–2.5 days and reduced tadpole survival by up to 25%, even though only a single tadpole was consumed. Tadpoles from captive-bred eggs had lower survival, growth, and greater loss in body condition after metamorphosis compared with tadpoles from wild eggs. We found that O. clarkii stomias do not innately avoid A. boreas boreas but instead strike tadpoles to determine prey palatability and repeated gustation likely reduced survival. Our results shed light on unresolved issues with A. boreas boreas captive breeding and demonstrate the nonconsumptive negative impacts of predators.

Effects of stream-adjacent logging in fishless headwaters on downstream coastal cutthroat trout

2016 ◽  
Vol 73 (12) ◽  
pp. 1898-1913 ◽  
Author(s):  
Douglas S. Bateman ◽  
Matthew R. Sloat ◽  
Robert E. Gresswell ◽  
Aaron M. Berger ◽  
David P. Hockman-Wert ◽  
...  
Keyword(s):  
Riparian Forest ◽  
Cutthroat Trout ◽  
Late Summer ◽  
Timber Harvest ◽  
Negative Effects ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout ◽  
Commercial Logging ◽  
Watershed Approach ◽  
Paired Watershed

To investigate effects of headwater logging on downstream coastal cutthroat trout (Oncorhynchus clarkii clarkii) populations, we monitored stream habitat and biotic indicators including biomass, abundance, growth, movement, and survival over 8 years using a paired-watershed approach. Reference and logged catchments were located on private industrial forestland on ∼60-year harvest rotation. Five clearcuts (14% of the logged catchment area) were adjacent to fishless portions of the headwater streams, and contemporary regulations did not require riparian forest buffers in the treatment catchment. Logging did not have significant negative effects on downstream coastal cutthroat trout populations for the duration of the sample period. Indeed, the only statistically significant response of fish populations following logging in fishless headwaters was an increase in late-summer biomass (g·m−2) of age-1+ coastal cutthroat trout in tributaries. Ultimately, the ability to make broad generalizations concerning effects of timber harvest is difficult because response to disturbance (anthropogenically influenced or not) in aquatic systems is complex and context-dependent, but our findings provide one example of environmentally compatible commercial logging in a regenerated forest setting.

scholarly journals Fear and stressing in predator–prey ecology: considering the twin stressors of predators and people on mammals

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9104
Author(s):  
Loren L. Fardell ◽  
Chris R. Pavey ◽  
Christopher R. Dickman
Keyword(s):  
Human Disturbance ◽  
Urban Areas ◽  
Captive Breeding ◽  
Common Knowledge ◽  
Ex Situ ◽  
Human Populations ◽  
Negative Effects ◽  
Natural Habitats ◽  
Predator Prey ◽  
Beneficial Effects

Predators induce stress in prey and can have beneficial effects in ecosystems, but can also have negative effects on biodiversity if they are overabundant or have been introduced. The growth of human populations is, at the same time, causing degradation of natural habitats and increasing interaction rates of humans with wildlife, such that conservation management routinely considers the effects of human disturbance as tantamount to or surpassing those of predators. The need to simultaneously manage both of these threats is particularly acute in urban areas that are, increasingly, being recognized as global hotspots of wildlife activity. Pressures from altered predator–prey interactions and human activity may each initiate fear responses in prey species above those that are triggered by natural stressors in ecosystems. If fear responses are experienced by prey at elevated levels, on top of responses to multiple environmental stressors, chronic stress impacts may occur. Despite common knowledge of the negative effects of stress, however, it is rare that stress management is considered in conservation, except in intensive ex situ situations such as in captive breeding facilities or zoos. We propose that mitigation of stress impacts on wildlife is crucial for preserving biodiversity, especially as the value of habitats within urban areas increases. As such, we highlight the need for future studies to consider fear and stress in predator–prey ecology to preserve both biodiversity and ecosystem functioning, especially in areas where human disturbance occurs. We suggest, in particular, that non-invasive in situ investigations of endocrinology and ethology be partnered in conservation planning with surveys of habitat resources to incorporate and reduce the effects of fear and stress on wildlife.

scholarly journals Hybridization rapidly reduces fitness of a native trout in the wild

2009 ◽  
Vol 5 (3) ◽  
pp. 328-331 ◽  
Author(s):  
Clint C. Muhlfeld ◽  
Steven T. Kalinowski ◽  
Thomas E. McMahon ◽  
Mark L. Taper ◽  
Sally Painter ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Cutthroat Trout ◽  
Biodiversity Loss ◽  
Parentage Analysis ◽  
Genetic Introgression ◽  
Negative Effects ◽  
Oncorhynchus Clarkii ◽  
Hybrid Swarms ◽  
In The Wild ◽  
Genomic Extinction

Human-mediated hybridization is a leading cause of biodiversity loss worldwide. How hybridization affects fitness and what level of hybridization is permissible pose difficult conservation questions with little empirical information to guide policy and management decisions. This is particularly true for salmonids, where widespread introgression among non-native and native taxa has often created hybrid swarms over extensive geographical areas resulting in genomic extinction. Here, we used parentage analysis with multilocus microsatellite markers to measure how varying levels of genetic introgression with non-native rainbow trout ( Oncorhynchus mykiss ) affect reproductive success (number of offspring per adult) of native westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) in the wild. Small amounts of hybridization markedly reduced fitness of male and female trout, with reproductive success sharply declining by approximately 50 per cent, with only 20 per cent admixture. Despite apparent fitness costs, our data suggest that hybridization may spread due to relatively high reproductive success of first-generation hybrids and high reproductive success of a few males with high levels of admixture. This outbreeding depression suggests that even low levels of admixture may have negative effects on fitness in the wild and that policies protecting hybridized populations may need reconsideration.

scholarly journals Social validity of a contextual behavioral science-based intervention for retirement education

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Leonardo Martins Barbosa ◽  
Sheila Giardini Murta
Keyword(s):  
Behavioral Science ◽  
Social Validity ◽  
Negative Effects ◽  
Acceptance And Commitment ◽  
Dynamic Methods ◽  
The Social ◽  
Group 3 ◽  
Group 2 ◽  
Negative Impacts ◽  
Contextual Behavioral Science

AbstractThe literature shows that retirement can bring both positive and negative effects. However, there are few tested interventions for preparing workers for this transition and avoiding or minimizing its negative impacts. This paper presents a study with multiple groups that examined the social validity of an intervention for retirement education grounded in contextual behavioral science and acceptance and commitment therapy. Twenty-seven workers aged 29 to 65 divided into three intervention groups participated (group 1, N = 15; group 2, N = 9; group 3, N = 3). According to the participants’ evaluations, the intervention provided socially valid goals, socially acceptable procedures, and socially important effects. However, some improvements are still needed, such as the use of more dynamic methods, better formatted printed material, and increased fidelity between the content’s implementation and the prescribed activities. The positive results indicate that contextual behavioral science may bolster the development of interventions whose components possess evidence for their social validity. The further evaluation of the intervention via a clinical trial study will offer more robust evidence for its effectiveness. It is hoped that by increasing the availability of theory-based interventions in this area, the present study will promote valid strategies to facilitate better adjustment to retirement.

scholarly journals Didymo and Its Polysaccharide Stalks: Beneficial to the Environment or Not?

2021 ◽  
Vol 2 (1) ◽  
pp. 69-79
Author(s):  
Hurmat Ejaz ◽  
Esther Somanader ◽  
Uday Dave ◽  
Hermann Ehrlich ◽  
M. Azizur Rahman
Keyword(s):  
Invasive Species ◽  
Structural Component ◽  
Negative Effects ◽  
Adhesive Properties ◽  
The Past ◽  
Positive Side ◽  
Potential Benefits ◽  
Negative Impacts ◽  
Bodies Of Water ◽  
Agricultural Setting

Didymosphenia geminata diatoms, or Didymo, was first found to be an invasive species that could have negative impacts on the environment due to the aggressive growth of its polysaccharide-based stalks. The stalks’ adhesive properties have prompted park officials to alert the general public to limit further spread and contamination of this algae to other bodies of water. Although the negative effects of Didymo have been studied in the past, recent studies have demonstrated a potential positive side to this alga. One of the potential benefits includes the structural component of the polysaccharide stalks. The origin of the polysaccharides within stalks remains unknown; however, they can be useful in a waste management and agricultural setting. The primary purpose of this study was to describe both the harmful and beneficial nature of Didymo. Important outcomes include findings related to its application in various fields such as medicine and technology. These polysaccharides can be isolated and studied closely to produce efficient solar power cells and batteries. Though they may be harmful while uncontained in nature, they appear to be very useful in the technological and medical advancement of our society.

scholarly journals Stated Preferences for Plant-Based and Cultured Meat: A Choice Experiment Study of Spanish Consumers

2021 ◽  
Vol 13 (15) ◽  
pp. 8235
Author(s):  
Alfredo J. Escribano ◽  
Maria Belen Peña ◽  
Carlos Díaz-Caro ◽  
Ahmed Elghannam ◽  
Eva Crespo-Cebada ◽  
...  
Keyword(s):  
Choice Experiment ◽  
Meat Products ◽  
Meat Production ◽  
Experiment Study ◽  
Negative Effects ◽  
High Quality ◽  
Cultured Meat ◽  
Production And Consumption ◽  
Alternative Sources ◽  
Negative Impacts

Meat production and consumption have been claimed to have negative impacts on the environment, and even on the consumer’s health. In this sense, alternative sources of protein, mainly meat substitutes and cultured meat, have emerged due to those perceived negative effects. Our paper carries out a choice experiment to analyze the preferences of 444 Spanish consumers and their willingness to pay for plant-based and cultured meats, as compared to conventional meat. Spain was considered of interest for this study due to its significant gastronomic culture, with high-quality meat products that make a great contribution to the economy, meaning that this could be a suitable and also challenging market in which to test alternative sources of protein. The findings show that consumers’ motivations and their interactions with these products are complex. Additionally, a cluster analysis allowed us to identify three types of consumers in terms of preference for these products: price-sensitive millennials, conscious/concerned consumers, and indifferent consumers. Only one group showed some level of acceptance of these alternative products meats.

Fungi and diseases — natural components of healthy forestsThis article is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005.

Botany ◽  
2009 ◽  
Vol 87 (1) ◽  
pp. 22-25 ◽  
Author(s):  
M. E. Ostry ◽  
G. Laflamme
Keyword(s):  
Fungal Pathogens ◽  
Biological Diversity ◽  
Forest Health ◽  
Disease Outbreaks ◽  
Ecological Interactions ◽  
Negative Effects ◽  
Land Owners ◽  
Negative Impacts ◽  
The Many ◽  
Native Fungi

Forest health is described and perceived in different ways by the general public, land owners, managers, politicians, and scientists, depending on their values and objectives. Native tree pathogens and diseases are often associated with negative impacts even though damage is limited or not widespread. Too often, the concepts of tree health and forest health are used interchangeably and are not related to scale. Similar to fire, occurrences of disease outbreaks focus on the negative effects. However, native pathogens often exist in equilibrium with natural forest communities so their critical ecological roles are not easily discernible. Examined holistically, native fungi and diseases, dead and dying trees, and the many complex ecological interactions among them provide valuable benefits that ultimately contribute to sustainable, healthy forest ecosystems.

A hormone priming regimen and hibernation affect oviposition in the boreal toad (Anaxyrus boreas boreas)

2015 ◽  
Vol 84 (4) ◽  
pp. 600-607 ◽  
Author(s):  
N.E. Calatayud ◽  
C.J. Langhorne ◽  
A.C. Mullen ◽  
C.L. Williams ◽  
T. Smith ◽  
...  
Keyword(s):  
Anaxyrus Boreas Boreas ◽  
Anaxyrus Boreas

Metabolic performance and thermal preference of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi and non-native trout across an ecologically relevant range of temperatures

2021 ◽  
Author(s):  
Camille J. Macnaughton ◽  
Travis C. Durhack ◽  
Neil J. Mochnacz ◽  
Eva C. Enders
Keyword(s):  
Brook Trout ◽  
Cold Water ◽  
Cutthroat Trout ◽  
Intermittent Flow ◽  
Performance Curve ◽  
Westslope Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Thermal Niche ◽  
Preferred Temperatures ◽  
Metabolic Performance

The physiology and behaviour of fish are strongly affected by ambient water temperature. Physiological traits related to metabolism, such as aerobic scope (AS), can be measured across temperature gradients and the resulting performance curve reflects the thermal niche that fish can occupy. We measured AS of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) at 5, 10, 15, 20, and 22°C and compared temperature preference (Tpref) of the species to non-native Brook Trout, Brown Trout, and Rainbow Trout. Intermittent-flow respirometry experiments demonstrated that metabolic performance of Westslope Cutthroat Trout was optimal at ~15 °C and decreased substantially beyond this temperature, until lethal temperatures at ~25 °C. Adjusted preferred temperatures across species (Tpref) were comparatively high, ranging from 17.8-19.9 °C, with the highest Tpref observed for Westslope Cutthroat Trout. Results suggest that although Westslope Cutthroat Trout is considered a cold-water species, they do not prefer or perform as well in cold water (≤ 10°C), thus, can occupy a warmer thermal niche than previously thought. The metabolic performance curve (AS) can be used to develop species‐specific thermal criteria to delineate important thermal habitats and guide conservation and recovery actions for Westslope Cutthroat Trout.

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