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There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, usingBatrachochytrium dendrobatidis, the fungus associated with worldwide amphibian declines, we test the hypothesis that there is enough variance in “novel” (quantified by geographic and phylogenetic distance) host‐pathogen outcomes to pose substantial risk of pathogen introductions despite local adaptation being common. Our continental‐scale common garden experiment and global‐scale meta‐analysis demonstrate that local amphibian‐fungal interactions result in higher pathogen prevalence, pathogen growth, and host mortality, but novel interactions led to variable consequences with especially virulent host‐pathogen combinations still occurring. Thus, while most pathogen introductions are benign, enough variance exists in novel host‐pathogen outcomes that moving organisms around the planet greatly increases the chance of pathogen introductions causing profound harm.

An understanding of the combined effects of climate change (CC) and other anthropogenic stressors, such as chemical exposures, is essential for improving ecological risk assessments of vulnerable ecosystems. In the Great Barrier Reef, coral reefs are under increasingly severe duress from increasing ocean temperatures, acidification, and cyclone intensities associated with CC. In addition to these stressors, inshore reef systems, such as the Mackay–Whitsunday coastal zone, are being impacted by other anthropogenic stressors, including chemical, nutrient, and sediment exposures related to more intense rainfall events that increase the catchment runoff of contaminated waters. To illustrate an approach for incorporating CC into ecological risk assessment frameworks, we developed an adverse outcome pathway network to conceptually delineate the effects of climate variables and photosystem II herbicide (diuron) exposures on scleractinian corals. This informed the development of a Bayesian network (BN) to quantitatively compare the effects of historical (1975–2005) and future projected climate on inshore hard coral bleaching, mortality, and cover. This BN demonstrated how risk may be predicted for multiple physical and biological stressors, including temperature, ocean acidification, cyclones, sediments, macroalgae competition, and crown of thorns starfish predation, as well as chemical stressors such as nitrogen and herbicides. Climate scenarios included an ensemble of 16 downscaled models encompassing current and future conditions based on multiple emission scenarios for two 30‐year periods. It was found that both climate‐related and catchment‐related stressors pose a risk to these inshore reef systems, with projected increases in coral bleaching and coral mortality under all future climate scenarios. This modeling exercise can support the identification of risk drivers for the prioritization of management interventions to build future resilient reefs.Integr Environ Assess Manag2024;20:401–418. © 2023 Norwegian Institute for Water Research and The Authors.Integrated Environmental Assessment and Managementpublished by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

The Society of Environmental Toxicology and Chemistry (SETAC) convened a Pellston workshop in 2022 to examine how information on climate change could be better incorporated into the ecological risk assessment (ERA) process for chemicals as well as other environmental stressors. A major impetus for this workshop is that climate change can affect components of ecological risks in multiple direct and indirect ways, including the use patterns and environmental exposure pathways of chemical stressors such as pesticides, the toxicity of chemicals in receiving environments, and the vulnerability of species of concern related to habitat quality and use. This article explores a modeling approach for integrating climate model projections into the assessment of near‐ and long‐term ecological risks, developed in collaboration with climate scientists. State‐of‐the‐art global climate modeling and downscaling techniques may enable climate projections at scales appropriate for the study area. It is, however, also important to realize the limitations of individual global climate models and make use of climate model ensembles represented by statistical properties. Here, we present a probabilistic modeling approach aiming to combine projected climatic variables as well as the associated uncertainties from climate model ensembles in conjunction with ERA pathways. We draw upon three examples of ERA that utilized Bayesian networks for this purpose and that also represent methodological advancements for better prediction of future risks to ecosystems. We envision that the modeling approach developed from this international collaboration will contribute to better assessment and management of risks from chemical stressors in a changing climate.Integr Environ Assess Manag2024;20:367–383. © 2023 The Authors.Integrated Environmental Assessment and Managementpublished by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Batrachochytrium dendrobatidis(Bd) has been associated with massive amphibian population declines worldwide. Wildlife vaccination campaigns have proven effective for mitigating damage from other pathogens, and there is evidence that adult frogs can acquire resistance to Bd when exposed to killed Bd zoospores and the metabolites they produced.

Agricultural expansion is predicted to increase agrochemical use two to fivefold by 2050 to meet food demand. Experimental evidence suggests that agrochemical pollution could increase snails that transmit schistosomiasis, a disease impacting 250 million people, yet most agrochemicals remain unexamined.

Heterogeneities in infections among host populations may arise through differences in environmental conditions through two mechanisms. First, environmental conditions may alter host exposure to pathogens via effects on survival. Second, environmental conditions may alter host susceptibility, making infection more or less likely if contact between a host and pathogen occurs. Further, host susceptibility might be altered through acquired resistance, which hosts can develop, in some systems, through exposure to dead or decaying pathogens and their metabolites. Environmental conditions may alter the rates of pathogen decomposition, influencing the likelihood of hosts developing acquired resistance.

Introduced hosts are capable of introducing parasite species and altering the abundance of parasites that are already present in native hosts, but few studies have compared the tolerances of native and invasive hosts to introduced parasites or identified the traits of introduced hosts that make them supershedders of non‐native parasites.

Climate change is a well‐documented driver and threat multiplier of infectious disease in wildlife populations. However, wildlife disease management and climate‐change adaptation have largely operated in isolation. To improve conservation outcomes, we consider the role of climate adaptation in initiating or exacerbating the transmission and spread of wildlife disease and the deleterious effects thereof, as illustrated through several case studies. We offer insights into best practices for disease‐smart adaptation, including a checklist of key factors for assessing disease risks early in the climate adaptation process. By assessing risk, incorporating uncertainty, planning for change, and monitoring outcomes, natural resource managers and conservation practitioners can better prepare for and respond to wildlife disease threats in a changing climate.

Prayer animal release (PAR)—a traditional “compassion‐based” religious practice of releasing captive animals into the wild to improve the karma of the releaser—has been regarded as a major anthropogenic pathway facilitating species invasions worldwide. However, comprehensive, quantitative assessments of PAR‐related invasion risks, crucial for the development of mitigation strategies, are lacking. To address this knowledge gap, we conducted a literature review of the prevalence of PAR events and examined the overlap between PAR intensity across China and habitat suitability for non‐native vertebrates released in these events. Our results revealed that 63% of the areas with high PAR intensity in China were also suitable for non‐native vertebrate establishment, a degree of overlap that was greater than expected by chance. In addition, field surveys in China detected higher richness of non‐native fishes at PAR sites than at non‐PAR sites. These findings imply an overall high risk of biological invasions associated with PARs. We recommend interdisciplinary cooperation among scientists, religious groups, and government agencies to effectively manage PARs and reduce the associated bioinvasion risk.