Atrazine toxicity to Handroanthus heptaphyllus , a nontarget species from a Brazilian biome threatened by agriculture

2021 ◽  
Author(s):  
Fabia Barbosa Silva ◽  
Alan Carlos Costa ◽  
Clarice Aparecida Megguer ◽  
Júlien Silva Lima ◽  
Priscila Ferreira Batista ◽  
...  
Keyword(s):  
Nontarget Species

Design of experimental food patches to measure foraging intensity for octopus: a case study with the giant Pacific octopus Enteroctopus dofleini

2020 ◽  
Author(s):  
Stephanie Chancellor ◽  
David Scheel ◽  
Joel S Brown
Keyword(s):  
Predation Risk ◽  
Foraging Behaviour ◽  
Habitat Preferences ◽  
High Tide ◽  
Intertidal Habitat ◽  
Camera System ◽  
Subtidal Habitat ◽  
Enteroctopus Dofleini ◽  
Nontarget Species

ABSTRACT In a study of the foraging behaviour of the giant Pacific octopus Enteroctopus dofleini, we designed two types of experimental food patches to measure habitat preferences and perceptions of predation risk. The first patch successfully measured giving-up densities (GUDs), confirmed by octopus prey presence and higher foraging at sites with historically greater octopus presence. However, nontarget foragers also foraged on these experimental food patches. Our second floating patch design successfully excluded nontarget species from subtidal patches, and from intertidal patches at high tide, but allowed for foraging by E. dofleini. The second design successfully measured GUDs and suggested that octopus preferred foraging in a subtidal habitat compared to an intertidal habitat. We ascribe the higher GUD in the intertidal habitat to its higher predation risk relative to the subtidal habitat. The second patch design seems well suited for E. dofleini and, in conjunction with a camera system, could be used to provide behavioural indicators of the octopus's abundance, perceptions of habitat quality and predation risk.

Adaptive Development of Yellow Toadflax (Linaria vulgaris) Chemical Control Recommendations

2015 ◽  
Vol 8 (3) ◽  
pp. 276-283
Author(s):  
Travis L. Almquist ◽  
Katie L. Wirt ◽  
Jason W. Adams ◽  
Rodney G. Lym
Keyword(s):  
North Dakota ◽  
Development Program ◽  
Control Program ◽  
Management Approach ◽  
Application Timing ◽  
Linaria Vulgaris ◽  
Yellow Toadflax ◽  
Nontarget Species ◽  
Adaptive Development

AbstractYellow toadflax (Linaria vulgaris P. Mill.) infestations in North Dakota increased 300-fold from 1997 to 2011, when the plant was added to the state noxious weed list. Long-term control of other invasive species had included biological control agents, but no effective agents for yellow toadflax had been identified, so a control program using herbicides was needed. The objective was to shift from short-term control with picloram applied in the fall at maximum allowed rates to long-term management with minimal nontarget species impact with an adaptive management approach. Yellow toadflax control was increased from an average of 64% with picloram at 1,120 g ha−1 alone 12 mo after treatment (MAT) to over 90% when applied with diflufenzopyr while the picloram rate was reduced 50%. Yellow toadflax control with aminocyclopyrachlor applied at 140 g ha−1 ranged from 91 to 49% 12 MAT when applied in June or September, respectively. In contrast, yellow toadflax control with picloram plus dicamba plus diflufenzopyr averaged > 90% regardless of application date during the growing season. Land managers now have at least two options for long-term yellow toadflax control with a wide window of application timing. The goal of replacing a single high-use–rate herbicide treatment was met but both picloram and aminocyclopyrachlor can injure many desirable forbs. However, application timing can now be adjusted to have the least impact on nontarget species. The adaptive development program led to a 58% reduction in yellow toadflax infestations in North Dakota by 2014.

Toxicity of VectoLex (Bacillus sphaericus) Products to Selected Australian Mosquito and Nontarget Species

2004 ◽  
Vol 97 (1) ◽  
pp. 51-58 ◽  
Author(s):  
M. D. Brown ◽  
T. M. Watson ◽  
J. Carter ◽  
D. M. Purdie ◽  
B. H. Kay
Keyword(s):  
Bacillus Sphaericus ◽  
Nontarget Species

Characterization of Western Painted Turtle Bycatch in Fyke Nets During Freshwater Fish Population Assessments

2015 ◽  
Vol 7 (1) ◽  
pp. 222-230 ◽  
Author(s):  
Tyrel S. Moos ◽  
Brian G. Blackwell
Keyword(s):  
Sex Ratio ◽  
Freshwater Fish ◽  
Significant Relationship ◽  
Annual Variation ◽  
Size Structure ◽  
Fish Population ◽  
Painted Turtle ◽  
Nontarget Species ◽  
Catch Rates ◽  
Fyke Nets

Abstract In fisheries management, fish populations are assessed using various net types that invariably also capture nontarget species. Although the bycatch of turtles tends to be a common occurrence, data describing the bycatch of turtles during freshwater fish sampling are lacking. To improve the available knowledge base concerning the bycatch of turtles during fish sampling, we characterize the dynamics of western painted turtle Chrysemys picta bellii bycatch in unbaited modified fyke nets used in fish population sampling in northeastern South Dakota. We collected data from June to September during fish population assessments in 39 lakes and nine impoundments between 2007 and 2012. We characterize western painted turtle bycatch relating to water type (lake and impoundment) including catch rates (number of turtles/net night), size structure, and sex ratio. Catch rates were higher in impoundments than lakes. Total mean annual catch rates ranged from 1.07 to 3.28 for lakes and from 0.70 to 6.63 for impoundments and the variation among years was significant for both water types. We observed no annual variation in water surface area or mean depth, precluding either from explaining the variation in annual catch rates. We observed a significant relationship between mean depth and catch rate for lakes, but not impoundments. We observed no significant relationship relating surface area to catch rate for lakes or impoundments. Catch rates differed significantly from June to September for lakes but not impoundments. Annual variation in catch rates was best explained by the previous winter precipitation for both water types. The sex ratio was skewed toward males and differed significantly from June to September for lakes but not impoundments. The size structure was skewed toward large turtles. Understanding bycatch dynamics during fish population assessments is a critical first step to understanding the impact of biological sampling on nontarget species and may prove useful in minimizing future bycatch of western painted turtles.

Impact of Spatial Management on Nontarget Species in an Oceanic Penaeid Trawl Fishery

2020 ◽  
Vol 40 (2) ◽  
pp. 509-520
Author(s):  
Matthew D. Taylor ◽  
Jack Silburn ◽  
David J. Booth ◽  
Daniel D. Johnson
Keyword(s):  
Trawl Fishery ◽  
Spatial Management ◽  
Nontarget Species

scholarly journals Nontarget Tree Mortality after Tree-of-Heaven (Ailanthus altissima) Injection with Imazapyr

2008 ◽  
Vol 25 (2) ◽  
pp. 66-72 ◽  
Author(s):  
Kevin Lewis ◽  
Brian McCarthy
Keyword(s):  
Mycorrhizal Fungi ◽  
Tree Mortality ◽  
Root Exudation ◽  
Ailanthus Altissima ◽  
Tree Of Heaven ◽  
Increased Risk ◽  
Vegetation Heterogeneity ◽  
Nontarget Species ◽  
Root Grafts ◽  
Injection Risk

Abstract Tree-of-heaven (Ailanthus altissima Miller [Swingle]) can be managed easily with herbicide injection. However, the potential herbicide translocation to neighboring trees must be evaluated before widespread recommendations for herbicide injections. We assessed the nontargettranslocation of imazapyr (Arsenal), an herbicide commonly used to manage woody vegetation in forests, from injected tree-of-heaven to neighboring noninjected stems. Targeted imazapyr injections not only killed all injected tree-of-heaven, but also killed 17.5% of neighboring (within 3 m) noninjected tree-of-heaven and eight other tree species 62 weeks after treatment. Nontarget mortality from herbicide translocation decreased as the distance from injected tree-of-heaven increased (up to 3 m) and as stem diameter of noninjected plants increased. The plausible modes ofinter- and intraspecific herbicide translocation include root grafts, mutually shared mycorrhizal fungi, root exudation and absorption, and/or leaf senescence. Because tree-of-heaven is clonal, patch size and vegetation heterogeneity will be an important determinant of herbicide injectionprotocols. In forest environments with many small patches (i.e., high edge to interior ratio) or mixed species stands, nontarget hardwoods are at an increased risk of mortality. In isolated large patches (with lower edge to interior ratio) or dense monospecific clones, injection risk to nontarget species will be relatively low.

scholarly journals RNAi-Based Insecticidal Crops: Potential Effects on Nontarget Species

BioScience ◽  
2013 ◽  
Vol 63 (8) ◽  
pp. 657-665 ◽  
Author(s):  
Jonathan G. Lundgren ◽  
Jian J. Duan
Keyword(s):  
Nontarget Species

scholarly journals Fisheries bycatch risk to marine megafauna is intensified in Lagrangian coherent structures

2018 ◽  
Vol 115 (28) ◽  
pp. 7362-7367 ◽  
Author(s):  
Kylie L. Scales ◽  
Elliott L. Hazen ◽  
Michael G. Jacox ◽  
Frederic Castruccio ◽  
Sara M. Maxwell ◽  
...  
Keyword(s):  
Real Time ◽  
Coherent Structures ◽  
Ocean Model ◽  
Lagrangian Coherent Structures ◽  
Lagrangian Analysis ◽  
Diverse Range ◽  
Major Barrier ◽  
The Real ◽  
Nontarget Species ◽  
Marine Megafauna

Incidental catch of nontarget species (bycatch) is a major barrier to ecological and economic sustainability in marine capture fisheries. Key to mitigating bycatch is an understanding of the habitat requirements of target and nontarget species and the influence of heterogeneity and variability in the dynamic marine environment. While patterns of overlap among marine capture fisheries and habitats of a taxonomically diverse range of marine vertebrates have been reported, a mechanistic understanding of the real-time physical drivers of bycatch events is lacking. Moving from describing patterns toward understanding processes, we apply a Lagrangian analysis to a high-resolution ocean model output to elucidate the fundamental mechanisms that drive fisheries interactions. We find that the likelihood of marine megafauna bycatch is intensified in attracting Lagrangian coherent structures associated with submesoscale and mesoscale filaments, fronts, and eddies. These results highlight how the real-time tracking of dynamic structures in the oceans can support fisheries sustainability and advance ecosystem-based management.

Differences in Bifenthrin and Fipronil Susceptibility Among Invasive Latrodectus spp. (Araneae: Theridiidae) and Nontarget Spiders in Japan

2021 ◽  
Author(s):  
Daisuke Hayasaka ◽  
Tomoki Numa ◽  
Takuo Sawahata
Keyword(s):  
Ecological Impacts ◽  
Toxicity Tests ◽  
Effective Population ◽  
Pyrethroid Insecticides ◽  
Parasteatoda Tepidariorum ◽  
Residual Toxicity ◽  
Insecticide Concentration ◽  
Nontarget Species ◽  
Spider Communities ◽  
Ecological Importance

Abstract Prompt responses to invasive Latrodectus spiders introduced unintentionally are needed worldwide due to their medical and ecological importance. Latrodectus species are chemically controlled using pyrethroid insecticides despite concerns about the ecological impacts of these compounds on biodiversity/ecosystems. Here, the relative sensitivities (acute toxicity: 48-h LC50) of Latrodectus hasseltii Thorell and Latrodectus geometricus C.L. Koch from Japan to the conventional neurotoxic insecticide bifenthrin (pyrethroid) and a new candidate insecticide, fipronil (phenylpyrazole), were examined. Acute residual toxicity tests of these compounds in two nontarget spiders (Parasteatoda tepidariorum C.L. Koch (Araneae: Theridiidae), Badumna insignis L. Koch (Araneae: Desidae)) were conducted for comparison. To test whether bifenthrin and fipronil toxicities differed among the four spiders, corresponding species sensitivity distributions (SSDs) were compared, and hazardous concentrations were determined. Sensitivity (especially in the nontarget species) was two to four orders of magnitude higher for bifenthrin than for fipronil. The SSD patterns of the two insecticides differed significantly, with the spider communities being more sensitive to bifenthrin than to fipronil. The lethal bifenthrin concentration for Latrodectus may reduce spider populations by over 70–90%. If L. hasseltii (established throughout Japan) is targeted for effective population suppression rather than L. geometricus (with a limited distribution range) using the specified insecticide concentration (LC50 value) for fipronil, less than 20% of spider communities will be impacted. Chemical operations aimed at the effective population management and subsequent eradication of invasive Latrodectus spiders while supporting local biodiversity conservation would benefit from considerations of fipronil dosages and target species sensitivities.

scholarly journals Methods To Measure Herbicide Volatility

Weed Science ◽  
2015 ◽  
Vol 63 (SP1) ◽  
pp. 116-120 ◽  
Author(s):  
Thomas C. Mueller
Keyword(s):  
Environmental Protection Agency ◽  
Target Area ◽  
Negative Effects ◽  
Agronomic Crops ◽  
Chemical Agents ◽  
Nontarget Species ◽  
Time Of Year ◽  
Plant Injury ◽  
Herbicide Drift ◽  
Herbicide Use

Herbicides are powerful chemical agents that exert strong biological activity on plants. The release of new formulations of dicamba and 2,4-D and their use in transgenic agronomic crops will probably result in many more applications during the time of year when sensitive nontarget vegetation will be present. The use of herbicides is regulated by the U.S. Environmental Protection Agency, and there are usually no negative effects on nontarget species. One negative aspect of herbicide use occurs when the application moves away from the target area and causes unwanted plant injury on susceptible species. Interest in herbicide drift is increasing, as evidenced by the number of refereed articles that investigate the mitigation or potential for herbicide drift (Figure 1). Although the topic of herbicide drift is broad, in this manuscript I will focus on an overview of off-site movement from a historical perspective and then discuss specific research protocols to examine vapor drift.

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