Asymmetry drives the cumulative impacts of multiple stressors on freshwater ecosystems under a warming climate

Climate warming is an important stressor in freshwater ecosystems, yet its interactive effects with other environmental changes are poorly understood. We address this challenge by testing the ability of three contrasting null models to predict the joint impacts of warming and a second stressor using a new database of 296 experimental combinations. Despite concerns that stressors will interact to cause synergisms, we found that net impacts were best explained by the effect of the worst stressor (the dominance null model). When this stressor’s impact was at least 50% greater than that of the second, the dominance model was most accurate in 62% of responses. Prediction accuracy depended on the identity of the stressors and declined at higher levels of biological organisation. Together these findings suggest we can often effectively forecast impacts of multiple stressors by focusing on the degree of asymmetry that exists among their independent impacts.

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Costs of living for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an increasingly warming and invaded world

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2012-094 ◽

2012 ◽

Vol 69 (10) ◽

pp. 1621-1630 ◽

Cited By ~ 17

Author(s):

Lauren M. Kuehne ◽

Julian D. Olden ◽

Jeffrey J. Duda

Keyword(s):

Chinook Salmon ◽

Oncorhynchus Tshawytscha ◽

Pacific Salmon ◽

Multiple Stressors ◽

Freshwater Ecosystems ◽

Smallmouth Bass ◽

Interactive Effects ◽

Physiological Indicators ◽

Juvenile Chinook Salmon ◽

Juvenile Chinook

Rapid environmental change in freshwater ecosystems has created a need to understand the interactive effects of multiple stressors, with temperature and invasive predators identified as key threats to imperiled fish species. We tested the separate and interactive effects of water temperature and predation by non-native smallmouth bass ( Micropterus dolomieu ) on the lethal (mortality) and sublethal (behavior, physiology, and growth) effects for juvenile Chinook salmon ( Oncorhynchus tshawytscha ) in seminatural stream channel experiments. Over 48 h trials, there was no difference in direct predation with warmer temperatures, but significant interactive effects on sublethal responses of juvenile salmon. Warmer temperatures resulted in significantly stronger and more variable antipredator responses (surface shoaling and swimming activity), while physiological indicators (plasma glucose, plasma cortisol) suggested suppression of physiological mechanisms in response to the combined stressors. These patterns corresponded with additive negative growth in predation, temperature, and combined treatments. Our results suggest that chronic increases in temperature may not increase direct predation over short periods, but can result in significant sublethal costs with negative implications for long-term development, disease resistance, and subsequent size-selective mortality of Pacific salmon.

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Editorial: Freshwater Ecosystems in Arid and Semiarid Zones Facing Multiple Stressors: Human Disturbances, Climate Change, and Dryland River Conservation

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.814225 ◽

2021 ◽

Vol 9 ◽

Author(s):

Eugenia López-López

Keyword(s):

Climate Change ◽

Multiple Stressors ◽

Freshwater Ecosystems ◽

Human Disturbances ◽

Dryland River ◽

River Conservation ◽

Arid And Semiarid

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Can Indirect Herbicide Exposure Modify the Response of the Colorado Potato Beetle to an Organophosphate Insecticide?

Journal of Economic Entomology ◽

10.1093/jee/toz115 ◽

2019 ◽

Vol 112 (5) ◽

pp. 2316-2323 ◽

Cited By ~ 3

Author(s):

Aigi Margus ◽

Miia Rainio ◽

Leena Lindström

Keyword(s):

Colorado Potato Beetle ◽

Target Genes ◽

Multiple Stressors ◽

Synergistic Effects ◽

Oxidative Status ◽

Interactive Effects ◽

Invasive Pest ◽

Lipid Hydroperoxides ◽

Organophosphate Insecticide ◽

Potato Beetle

AbstractOrganisms live in complex multivariate environments. In agroecosystems, this complexity is often human-induced as pest individuals can be exposed to many xenobiotics simultaneously. Predicting the effects of multiple stressors can be problematic, as two or more stressors can have interactive effects. Our objective was to investigate whether indirect glyphosate-based herbicide (GBH) exposure of the host plant has interactive effects in combination with an insecticide (azinphos-methyl) on an invasive pest Colorado potato beetle (Leptinotarsa decemlineata Say). We tested the effects of GBH and insecticide on the survival, insecticide target genes expression (acetylcholinesterase genes) and oxidative status biomarkers (glutathione S-transferase [GST], glucose-6-phosphate dehydrogenase [G6PDH], glutathione reductase homolog [GR], glutathione peroxidase homolog [GPx], total glutathione [totGSH], glutathione reduced-oxidized [GSH: GSSG], catalase [CAT], superoxide dismutase [SOD], lipid hydroperoxides). We found that exposure to indirect GBH has no single or interactive effects in combination with the insecticide on larval survival. However, prior exposure to GBH inhibits Ldace1 gene expression by 0.55-fold, which is the target site for the organophosphate and carbamate insecticides. This difference disappears when individuals are exposed to both GBH and insecticide, suggesting an antagonistic effect. On the other hand, oxidative status biomarker scores (PCAs of GPx, GR, and CAT) were decreased when exposed to both stressors, indicating a synergistic effect. Overall, we found that indirect GBH exposure can have both antagonistic and synergistic effects in combination with an insecticide, which should be considered when aiming for an ecologically relevant risk assessment of multiple human-induced stressors.

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A Metacommunity Approach to Improve Biological Assessments in Highly Dynamic Freshwater Ecosystems

BioScience ◽

10.1093/biosci/biaa033 ◽

2020 ◽

Vol 70 (5) ◽

pp. 427-438 ◽

Cited By ~ 9

Author(s):

Núria Cid ◽

Núria Bonada ◽

Jani Heino ◽

Miguel Cañedo-Argüelles ◽

Julie Crabot ◽

...

Keyword(s):

Environmental Changes ◽

Environmental Variability ◽

Anthropogenic Impacts ◽

Dispersal Limitation ◽

Freshwater Ecosystems ◽

Metacommunity Ecology ◽

Intermittent Rivers ◽

Biological Assessments ◽

Quality Assessments ◽

Flow Intermittence

Abstract Rapid shifts in biotic communities due to environmental variability challenge the detection of anthropogenic impacts by current biomonitoring programs. Metacommunity ecology has the potential to inform such programs, because it combines dispersal processes with niche-based approaches and recognizes variability in community composition. Using intermittent rivers—prevalent and highly dynamic ecosystems that sometimes dry—we develop a conceptual model to illustrate how dispersal limitation and flow intermittence influence the performance of biological indices. We produce a methodological framework integrating physical- and organismal-based dispersal measurements into predictive modeling, to inform development of dynamic ecological quality assessments. Such metacommunity-based approaches could be extended to other ecosystems and are required to underpin our capacity to monitor and protect ecosystems threatened under future environmental changes.

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Towards a unified study of multiple stressors: divisions and common goals across research disciplines

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.0421 ◽

2020 ◽

Vol 287 (1926) ◽

pp. 20200421 ◽

Cited By ~ 12

Author(s):

James A. Orr ◽

Rolf D. Vinebrooke ◽

Michelle C. Jackson ◽

Kristy J. Kroeker ◽

Rebecca L. Kordas ◽

...

Keyword(s):

Environmental Changes ◽

Multiple Stressors ◽

Knowledge Exchange ◽

Ecological Impacts ◽

Temporal Complexity ◽

Multiple Stressor ◽

Interdisciplinary Knowledge ◽

Shared Goal ◽

Common Goals ◽

Meta Analyses

Anthropogenic environmental changes, or ‘stressors’, increasingly threaten biodiversity and ecosystem functioning worldwide. Multiple-stressor research is a rapidly expanding field of science that seeks to understand and ultimately predict the interactions between stressors. Reviews and meta-analyses of the primary scientific literature have largely been specific to either freshwater, marine or terrestrial ecology, or ecotoxicology. In this cross-disciplinary study, we review the state of knowledge within and among these disciplines to highlight commonality and division in multiple-stressor research. Our review goes beyond a description of previous research by using quantitative bibliometric analysis to identify the division between disciplines and link previously disconnected research communities. Towards a unified research framework, we discuss the shared goal of increased realism through both ecological and temporal complexity, with the overarching aim of improving predictive power. In a rapidly changing world, advancing our understanding of the cumulative ecological impacts of multiple stressors is critical for biodiversity conservation and ecosystem management. Identifying and overcoming the barriers to interdisciplinary knowledge exchange is necessary in rising to this challenge. Division between ecosystem types and disciplines is largely a human creation. Species and stressors cross these borders and so should the scientists who study them.

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Invasion-mediated effects on marine trophic interactions in a changing climate: positive feedbacks favour kelp persistence

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.2866 ◽

2019 ◽

Vol 286 (1899) ◽

pp. 20182866 ◽

Cited By ~ 5

Author(s):

Ricardo J. Miranda ◽

Melinda A. Coleman ◽

Alejandro Tagliafico ◽

Maria S. Rangel ◽

Lea T. Mamo ◽

...

Keyword(s):

Climate Change ◽

Trophic Interactions ◽

Multiple Stressors ◽

Grazing Intensity ◽

Ocean Warming ◽

Interactive Effects ◽

Ecological Change ◽

Climate Change Scenarios ◽

Ecological Consequences ◽

Management Actions

The interactive effects of ocean warming and invasive species are complex and remain a source of uncertainty for projecting future ecological change. Climate-mediated change to trophic interactions can have pervasive ecological consequences, but the role of invasion in mediating trophic effects is largely unstudied. Using manipulative experiments in replicated outdoor mesocosms, we reveal how near-future ocean warming and macrophyte invasion scenarios interactively impact gastropod grazing intensity and preference for consumption of foundation macroalgae ( Ecklonia radiata and Sargassum vestitum ). Elevated water temperature increased the consumption of both macroalgae through greater grazing intensity. Given the documented decline of kelp ( E. radiata ) growth at higher water temperatures, enhanced grazing could contribute to the shift from kelp-dominated to Sargassum -dominated reefs that is occurring at the low-latitude margins of kelp distribution. However, the presence of a native invader ( Caulerpa filiformis ) was related to low consumption by the herbivores on dominant kelp at warmer temperatures. Thus, antagonistic effects between climate change and a range expanding species can favour kelp persistence in a warmer future. Introduction of species should, therefore, not automatically be considered unfavourable under climate change scenarios. Climatic changes are increasing the need for effective management actions to address the interactive effects of multiple stressors and their ecological consequences, rather than single threats in isolation.

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Multiple Stressors Determine Community Structure and Estimated Function of River Biofilm Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.00291-20 ◽

2020 ◽

Vol 86 (12) ◽

Cited By ~ 1

Author(s):

Ferran Romero ◽

Vicenç Acuña ◽

Sergi Sabater

Keyword(s):

Bacterial Community ◽

Community Composition ◽

Bacterial Communities ◽

Pesticide Exposure ◽

Multiple Stressors ◽

Bacterial Community Composition ◽

Freshwater Ecosystems ◽

Low Flow ◽

Hydrological Stress ◽

The Individual

ABSTRACT Freshwater ecosystems are exposed to multiple stressors, but their individual and combined effects remain largely unexplored. Here, we investigated the response of stream biofilm bacterial communities to warming, hydrological stress, and pesticide exposure. We used 24 artificial streams on which epilithic (growing on coarse sediments) and epipsammic (growing on fine sediments) stream biofilms were maintained. Bacterial community composition and estimated function of biofilms exposed during 30 days to individual and combined stressors were assessed using 16S rRNA gene metabarcoding. Among the individual effects by stressors, hydrological stress (i.e., a simulated low-flow situation) was the most relevant, since it significantly altered 57% of the most abundant bacterial taxa (n = 28), followed by warming (21%) and pesticide exposure (11%). Regarding the combined effects, 16% of all stressor combinations resulted in significant interactions on bacterial community composition and estimated function. Antagonistic responses prevailed (57 to 89% of all significant interactions), followed by synergisms (11 to 43%), on specific bacterial taxa, indicating that multiple-stressor scenarios could lead to unexpected shifts in the community composition and associated functions of riverine bacterial communities. IMPORTANCE Freshwater ecosystems such as rivers are of crucial importance for human well-being. However, human activities result in many stressors (e.g., toxic chemicals, increased water temperatures, and hydrological alterations) cooccurring in rivers and streams worldwide. Among the many organisms inhabiting rivers and streams, bacteria are ecologically crucial; they are placed at the base of virtually all food webs and they recycle the organic matter needed for bigger organisms. Most of these bacteria are in close contact with river substratum, where they form the biofilms. There is an urgent need to evaluate the effects of these stressors on river biofilms, so we can anticipate future environmental problems. In this study, we experimentally exposed river biofilms to a pesticide mixture, an increase in water temperature and a simulated low-flow condition, in order to evaluate the individual and joint effects of these stressors on the bacterial community composition and estimated function.

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