Physiological and genomic mechanisms of resilience to multiple environmental stressors

Fernando Galvez, Louisiana State University

Abstract

© Springer International Publishing AG, part of Springer Nature 2018. All rights reserved. Though much attention has focused on single environmental variables, most notably temperature and acidification, global climate change is most realistically to manifest as co-occurring and sustained variations in multiple environmental variables or in more frequent, but episodic, fluctuations in environmental conditions. Environmental variability is likely to produce physiological stress to organisms and may supersede the organismic capacity to handle stressor(s) when their rate or magnitude of change is high. Unfortunately, multiple stressor experiments predictive of natural systems remain difficult to perform. Multiple stressors may produce additive, synergistic, or antagonistic effects that are not always predictable from the impacts of the stressors in isolation. Furthermore, physiological variation is harbored within species and individuals, and this natural variation for resistance or resilience to one stressor may be attenuated by co-occurrence of additional stressors. As such, the combination of factors that limit physiological resilience in at-risk populations remains elusive. After a brief description of stress biology, this chapter will describe the sources of ocean acidification and its biological impacts on the biota of marine systems. It will next describe the major drivers of oceanic deoxygenation and temperature warming as well as provide a brief discussion of the effects of these environmental stressors on aquatic animals. Next, it will discuss the environmental conditions that favor co-occurrence of these stressors in nature and how global climate change has exacerbated the magnitude and frequency of these multiple stressor interactions in nature. Finally, it will investigate how chronic exposure to new baselines in baselines in environments will sensitize or buffer organisms from acute fluctuations in environmental parameters and discuss how naturalevolved variation among populations and species may sensitize or buffer wild animals from altered environments. This will address one of the grand challenges in organismal biology, which is the effective integration of molecular through whole animal responses to natural systems.