The Experts below are selected from a list of 7490670 Experts worldwide ranked by ideXlab platform
Jeremy J Piggott - One of the best experts on this subject based on the ideXlab platform.
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Making Waves. Bridging theory and practice towards multiple stressor management in freshwater ecosystems
Water research, 2021Co-Authors: Bryan M. Spears, Christian K. Feld, Cayetano Gutiérrez-cánovas, Jeremy J Piggott, Daniel S. Chapman, Laurence Carvalho, Mark O. Gessner, Lindsay F. Banin, Anne Lyche Solheim, Jessica RichardsonAbstract:Abstract Despite advances in conceptual understanding, single-stressor abatement approaches remain common in the management of fresh waters, even though they can produce unexpected ecological responses when multiple Stressors interact. Here we identify limitations restricting the development of multiple-stressor management strategies and address these, bridging theory and practice, within a novel empirical framework. Those critical limitations include that (i) monitoring schemes fall short of accounting for theory on relationships between multiple-stressor interactions and ecological responses, (ii) current empirical modelling approaches neglect the prevalence and intensity of multiple-stressor interactions, and (iii) mechanisms of stressor interactions are often poorly understood. We offer practical recommendations for the use of empirical models and experiments to predict the effects of freshwater degradation in response to changes in multiple Stressors, demonstrating this approach in a case study. Drawing on our framework, we offer practical recommendations to support the development of effective management strategies in three general multiple-stressor scenarios.
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anthropogenic Stressors affect fungal more than bacterial communities in decaying leaf litter a stream mesocosm experiment
Science of The Total Environment, 2020Co-Authors: Noel P D Juvignykhenafou, Jeremy J Piggott, David Atkinson, Yixin Zhang, Christoph D Matthaei, Sunshine A Van BaelAbstract:Abstract Despite the progress made in environmental microbiology techniques and knowledge, the succession and functional changes of the microbial community under multiple Stressors are still poorly understood. This is a substantial knowledge gap as microbial communities regulate the biogeochemistry of stream ecosystems. Our study assessed the structural and temporal changes in stream fungal and bacterial communities associated with decomposing leaf litter under a multiple-stressor scenario. We conducted a fully crossed 4-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 days of colonisation, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and sedimentation after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S and 18S rRNA genes) to identify changes in microbial community composition. Our results indicate that (1) shifts in relative abundances of the pre-existing terrestrial microbial community, rather than changes in community identity, drove the observed responses to Stressors; (2) changes in relative abundances within the microbial community paralleled decomposition rate patterns with time; (3) both fungal and bacterial communities had a certain resistance to Stressors, as indicated by relatively minor changes in alpha diversity or multivariate community structure; (4) overall, stressor interactions were more common than stressor main effects when affecting microbial diversity metrics or abundant individual genera; and (5) stressor effects on microbes often changed from 2 weeks to 3 weeks of stressor exposure, with several response patterns being reversed. Our study suggests that future research should focus more on understanding the temporal dynamics of fungal and bacterial communities and how they relate to ecosystem processes to advance our understanding of the mechanisms associated with multiple-stressor interactions.
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Advancing understanding and prediction in multiple stressor research through a mechanistic basis for null models.
Global change biology, 2018Co-Authors: Ralf B. Schäfer, Jeremy J PiggottAbstract:Global environmental change is driven by multiple anthropogenic Stressors. Conservation and restoration require understanding the individual and joint action of these Stressors to evaluate and prioritize management measures. To date, most studies on multiple stressor effects have sought to identify potential stressor interactions, defined as deviations from null models, and related meta-analyses have focused on quantifying the relative proportion of stressor interactions across studies. These studies have provided valuable insights about the complexity of multiple stressor effects, but remain largely devoid of a theoretical framework for null model selection and prediction of effects. We suggest that multiple stressor research would benefit by (1) integrating and developing additional null models and (2) selecting null models based on their mechanistic assumptions of the stressor mode of action and organism sensitivities as well as stressor-effect relationships for individuals and populations. We present a range of null models and outline their underlying assumptions and application in multiple stressor research. Moving beyond mere description requires multiple stressor research to shift its focus from identifying statistically significant interactions to the use and development of mechanistic (null) models. Justified selection of the appropriate null model is a first step to achieve this.
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multiple stressor effects on stream macroinvertebrate communities a mesocosm experiment manipulating salinity fine sediment and flow velocity
Science of The Total Environment, 2018Co-Authors: Arne J Beermann, Jeremy J Piggott, Christoph D Matthaei, Vasco Elbrecht, Svenja Karnatz, Florian LeeseAbstract:Stream ecosystems are impacted by multiple Stressors worldwide. Recent studies have shown that the effects of multiple Stressors are often complex and difficult to predict based on the effects of single Stressors. More research is needed to understand stressor impacts on stream communities and to design appropriate counteractions. We carried out an outdoor mesocosm experiment to assess single and interactive multiple-stressor effects on stream macroinvertebrates in a setup with controlled application of three globally important Stressors, namely, reduced stream flow velocity, deposition of fine sediment and increased chloride concentration in a full-factorial design. Each mesocosm comprised three compartments (channel substratum, leaf litter bag and drift net) that were individually analyzed and also compared. We identified 102,501 specimens in total (mainly to family level), 36.5% of which were found in the substratum, 60.6% in litter bags and 2.9% in the drift. Added fine sediment and reduced flow velocity had strong negative single-stressor effects on the abundances of EPT taxa, i.e. Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies), and a positive effect on chironomid abundances in the substratum. Increased salt concentration reduced abundances of Ephemeroptera. Chironomids migrated from litter bag to channel substratum when water velocity was reduced and Leptophlebiidae in the opposite direction when sediment was added. All three Stressors caused higher drift propensities, especially added fine sediment. Both additive and complex multiple-stressor effects were common. A complex three-way interaction affected EPT richness in the substratum, demonstrating the need to evaluate higher-order interactions for more than two Stressors. Our results add further evidence that multiple-stressor interactions, notably increased salinity with other Stressors, affect a variety of invertebrate taxa across different habitats of stream communities. The results have direct implications for water management as they highlight the need to re-evaluate defined salinity thresholds in the context of multiple-stressor interactions.
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multiple stressor effects on stream invertebrates a mesocosm experiment manipulating nutrients fine sediment and flow velocity
Freshwater Biology, 2016Co-Authors: Arne J Beermann, Vasco Elbrecht, Gunnar Goessler, Janis Neumann, Ralph Tollrian, Rudiger Wagner, Andre Wlecklik, Jeremy J PiggottAbstract:Summary Land-use changes have degraded ecosystems worldwide. A particular concern for freshwater biodiversity and ecosystem function are Stressors introduced by intensified agriculture. Typically several Stressors affect freshwater ecosystems simultaneously. However, the combined effects of these multiple Stressors on streams and rivers are still poorly understood, yet of critical importance to improve freshwater management. We investigated responses of benthic macroinvertebrates to three globally important agricultural Stressors affecting streams (nutrient enrichment, fine sediment deposition and reduced current velocity), using 64 stream mesocosms (full-factorial 2 × 2 × 2 design, eight replicates of each treatment combination) established on the banks of the Breitenbach Stream (Hesse, Germany). The experiment ran for 1 month (16 days of colonisation, 14 days of manipulations), and all invertebrates in the mesocosms were collected at the end of this period. Fourteen of the 17 studied invertebrate response variables were affected by one or more Stressors each. Negative effects on richness or abundance of pollution-sensitive Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa were particularly common. Overall, both sediment addition and stream flow velocity reduction had pervasive and strong effects. Responses to sediment addition were mostly negative, whereas decreased current velocity reduced several EPT metrics but increased the abundances of some of the other common taxa. Nutrient enrichment had few effects, but these were consistently negative. Combined stressor effects were mainly additive, with only two interactions found in total, both between reduced velocity and nutrients (on the crustacean Gammarus spp. and ceratopogonid midges). This finding implies that multiple-stressor responses may be predicted from knowledge of single-stressor effects in this stream community (unlike the often synergistic or antagonistic responses observed elsewhere). However, further taxon-specific responses and interactions among Stressors may have been obscured by limited taxonomic resolution, especially for the numerically dominant Chironomidae. Genetic approaches are required to address this limitation in the future.
David Lecchini - One of the best experts on this subject based on the ideXlab platform.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature communications, 2020Co-Authors: Marc Besson, William E. Feeney, Isadora Moniz, Loïc François, Rohan M. Brooker, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 µg L−1) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities. Anthropogenic Stressors affect many aspects of marine organismal health. Here, the authors expose surgeonfish to temperature and pesticide Stressors and show that the Stressors, separately and in combination, have adverse effects on thyroid signaling, which disrupts several sensory systems and important predation defenses.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature Communications, 2020Co-Authors: Marc Besson, Isadora Moniz, Loïc François, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, William Feeney, Rohan Brooker, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 μg L −1 ) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities.
Marc Besson - One of the best experts on this subject based on the ideXlab platform.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature communications, 2020Co-Authors: Marc Besson, William E. Feeney, Isadora Moniz, Loïc François, Rohan M. Brooker, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 µg L−1) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities. Anthropogenic Stressors affect many aspects of marine organismal health. Here, the authors expose surgeonfish to temperature and pesticide Stressors and show that the Stressors, separately and in combination, have adverse effects on thyroid signaling, which disrupts several sensory systems and important predation defenses.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature Communications, 2020Co-Authors: Marc Besson, Isadora Moniz, Loïc François, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, William Feeney, Rohan Brooker, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 μg L −1 ) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities.
Christoph D Matthaei - One of the best experts on this subject based on the ideXlab platform.
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anthropogenic Stressors affect fungal more than bacterial communities in decaying leaf litter a stream mesocosm experiment
Science of The Total Environment, 2020Co-Authors: Noel P D Juvignykhenafou, Jeremy J Piggott, David Atkinson, Yixin Zhang, Christoph D Matthaei, Sunshine A Van BaelAbstract:Abstract Despite the progress made in environmental microbiology techniques and knowledge, the succession and functional changes of the microbial community under multiple Stressors are still poorly understood. This is a substantial knowledge gap as microbial communities regulate the biogeochemistry of stream ecosystems. Our study assessed the structural and temporal changes in stream fungal and bacterial communities associated with decomposing leaf litter under a multiple-stressor scenario. We conducted a fully crossed 4-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 days of colonisation, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and sedimentation after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S and 18S rRNA genes) to identify changes in microbial community composition. Our results indicate that (1) shifts in relative abundances of the pre-existing terrestrial microbial community, rather than changes in community identity, drove the observed responses to Stressors; (2) changes in relative abundances within the microbial community paralleled decomposition rate patterns with time; (3) both fungal and bacterial communities had a certain resistance to Stressors, as indicated by relatively minor changes in alpha diversity or multivariate community structure; (4) overall, stressor interactions were more common than stressor main effects when affecting microbial diversity metrics or abundant individual genera; and (5) stressor effects on microbes often changed from 2 weeks to 3 weeks of stressor exposure, with several response patterns being reversed. Our study suggests that future research should focus more on understanding the temporal dynamics of fungal and bacterial communities and how they relate to ecosystem processes to advance our understanding of the mechanisms associated with multiple-stressor interactions.
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Multiple‐stressor effects on freshwater fish: Importance of taxonomy and life stage
Fish and Fisheries, 2018Co-Authors: Katharina Lange, Christoph D Matthaei, Andreas Bruder, Jakob Brodersen, Rachel A. PatersonAbstract:Interactions among multiple anthropogenic Stressors threaten freshwater fish and pose challenges for fisheries management and conservation. Previous studies of multiple‐stressor effects on freshwater fish suggest a prevalence of antagonistic interactions. However, taxonomy, life stage and/or environmental context likely modify the magnitude and direction of fish responses to multiple Stressors. Stressor intensity, impact mechanism, exposure time and ecosystem size may further affect interaction outcomes. Large‐scale studies quantifying how these variables moderate stressor interactions are lacking. To address this knowledge gap, we performed a meta‐analysis of 29 factorial multiple‐stressor experiments to examine the influence of seven potential moderator variables on the magnitude and direction of stressor interactions. Using weighted random‐effects meta‐analytic models, we demonstrate the importance of taxonomic identity and life stage for interaction outcomes. In particular, Cypriniformes showed stronger antagonisms than Salmoniformes, as did larval fish compared to juveniles. Interaction outcomes also varied among the measured fish responses with survival yielding stronger antagonisms than biomass. Increasing experimental duration and volume of the experimental units both drove interactions towards synergisms, supporting findings from previous studies that synergisms take time and space to develop. In an era when the number of Stressors affecting freshwater systems is increasing rapidly, our study provides a vital step towards identifying generalities in multiple‐stressor outcomes and thus improved predictions of multiple‐stressor impacts. Furthermore, our meta‐analysis complements studies in real streams, rivers and lakes by providing an experimentally derived context for the growing number of multiple‐stressor assessments in research, management and conservation of freshwater fish.
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multiple stressor effects on stream macroinvertebrate communities a mesocosm experiment manipulating salinity fine sediment and flow velocity
Science of The Total Environment, 2018Co-Authors: Arne J Beermann, Jeremy J Piggott, Christoph D Matthaei, Vasco Elbrecht, Svenja Karnatz, Florian LeeseAbstract:Stream ecosystems are impacted by multiple Stressors worldwide. Recent studies have shown that the effects of multiple Stressors are often complex and difficult to predict based on the effects of single Stressors. More research is needed to understand stressor impacts on stream communities and to design appropriate counteractions. We carried out an outdoor mesocosm experiment to assess single and interactive multiple-stressor effects on stream macroinvertebrates in a setup with controlled application of three globally important Stressors, namely, reduced stream flow velocity, deposition of fine sediment and increased chloride concentration in a full-factorial design. Each mesocosm comprised three compartments (channel substratum, leaf litter bag and drift net) that were individually analyzed and also compared. We identified 102,501 specimens in total (mainly to family level), 36.5% of which were found in the substratum, 60.6% in litter bags and 2.9% in the drift. Added fine sediment and reduced flow velocity had strong negative single-stressor effects on the abundances of EPT taxa, i.e. Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies), and a positive effect on chironomid abundances in the substratum. Increased salt concentration reduced abundances of Ephemeroptera. Chironomids migrated from litter bag to channel substratum when water velocity was reduced and Leptophlebiidae in the opposite direction when sediment was added. All three Stressors caused higher drift propensities, especially added fine sediment. Both additive and complex multiple-stressor effects were common. A complex three-way interaction affected EPT richness in the substratum, demonstrating the need to evaluate higher-order interactions for more than two Stressors. Our results add further evidence that multiple-stressor interactions, notably increased salinity with other Stressors, affect a variety of invertebrate taxa across different habitats of stream communities. The results have direct implications for water management as they highlight the need to re-evaluate defined salinity thresholds in the context of multiple-stressor interactions.
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reconceptualizing synergism and antagonism among multiple Stressors
Ecology and Evolution, 2015Co-Authors: Jeremy J Piggott, Colin R Townsend, Christoph D MatthaeiAbstract:The potential for complex synergistic or antagonistic interactions between multiple Stressors presents one of the largest uncertainties when predicting ecological change but, despite common use of the terms in the scientific literature, a consensus on their operational definition is still lacking. The identification of synergism or antagonism is generally straightforward when Stressors operate in the same direction, but if individual stressor effects oppose each other, the definition of synergism is paradoxical because what is synergistic to one stressor's effect direction is antagonistic to the others. In their highly cited meta-analysis, Crain et al. (Ecology Letters, 11, 2008: 1304) assumed in situations with opposing individual effects that synergy only occurs when the cumulative effect is more negative than the additive sum of the opposing individual effects. We argue against this and propose a new systematic classification based on an additive effects model that combines the magnitude and response direction of the cumulative effect and the interaction effect. A new class of “mitigating synergism” is identified, where cumulative effects are reversed and enhanced. We applied our directional classification to the dataset compiled by Crain et al. (Ecology Letters, 11, 2008: 1304) to determine the prevalence of synergistic, antagonistic, and additive interactions. Compared to their original analysis, we report differences in the representation of interaction classes by interaction type and we document examples of mitigating synergism, highlighting the importance of incorporating individual stressor effect directions in the determination of synergisms and antagonisms. This is particularly pertinent given a general bias in ecology toward investigating and reporting adverse multiple stressor effects (double negative). We emphasize the need for reconsideration by the ecological community of the interpretation of synergism and antagonism in situations where individual stressor effects oppose each other or where cumulative effects are reversed and enhanced.
Guillaume Holzer - One of the best experts on this subject based on the ideXlab platform.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature communications, 2020Co-Authors: Marc Besson, William E. Feeney, Isadora Moniz, Loïc François, Rohan M. Brooker, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 µg L−1) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities. Anthropogenic Stressors affect many aspects of marine organismal health. Here, the authors expose surgeonfish to temperature and pesticide Stressors and show that the Stressors, separately and in combination, have adverse effects on thyroid signaling, which disrupts several sensory systems and important predation defenses.
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Anthropogenic Stressors impact fish sensory development and survival via thyroid disruption
Nature Communications, 2020Co-Authors: Marc Besson, Isadora Moniz, Loïc François, Guillaume Holzer, Marc Metian, Natacha Roux, Vincent Laudet, William Feeney, Rohan Brooker, David LecchiniAbstract:Larval metamorphosis and recruitment represent critical life-history transitions for most teleost fishes. While the detrimental effects of anthropogenic Stressors on the behavior and survival of recruiting fishes are well-documented, the physiological mechanisms that underpin these patterns remain unclear. Here, we use pharmacological treatments to highlight the role that thyroid hormones (TH) play in sensory development and determining anti-predator responses in metamorphosing convict surgeonfish, Acanthurus triostegus. We then show that high doses of a physical stressor (increased temperature of +3 °C) and a chemical stressor (the pesticide chlorpyrifos at 30 μg L −1 ) induced similar defects by decreasing fish TH levels and affecting their sensory development. Stressor-exposed fish experienced higher predation; however, their ability to avoid predation improved when they received supplemental TH. Our results highlight that two different anthropogenic Stressors can affect critical developmental and ecological transitions via the same physiological pathway. This finding provides a unifying mechanism to explain past results and underlines the profound threat anthropogenic Stressors pose to fish communities.
