Multiple Stressors in a Changing World: The Need for an Improved Perspective on Physiological Responses to the Dynamic Marine Environment

Abstract

Abiotic conditions (e.g., temperature and pH) fluctuate through time in most marine environments, sometimes passing intensity thresholds that induce physiological stress. Depending on habitat and season, the peak intensity of different abiotic stressors can occur in or out of phase with one another. Thus, some organisms are exposed to multiple stressors simultaneously, whereas others experience them sequentially. Understanding these physicochemical dynamics is critical because how organisms respond to multiple stressors depends on the magnitude and relative timing of each stressor. Here, we first discuss broad patterns of covariation between stressors in marine systems at various temporal scales. We then describe how these dynamics will influence physiological responses to multi-stressor exposures. Finally, we summarize how multi-stressor effects are currently assessed. We find that multi-stressor experiments have rarely incorporated naturalistic physicochemical variation into their designs, and emphasize the importance of doing so to make ecologically relevant inferences about physiological responses to global change.

Aquatic insects in a multistress environment: cross-tolerance to salinity and desiccation

“…The persistence of animal populations in dynamic and multivariate environments greatly depends on their ability to deal with the interactive effects of different stressors occurring simultaneously or sequentially over short time scales (Gunderson et al, 2016). Exposure to a particular stressor might enhance tolerance to a subsequent stress if the physiological protective mechanisms against the two stressors are shared (cross-tolerance, e.g.…”

“…Studies on multiple stressors have received increasing attention for their potential to reveal interesting information, which would be difficult to predict based on single stressor approaches (DeBiasse and Kelly, 2016;Gunderson et al, 2016), as well as to increase our understanding of responses to global change in natural multivariate environments (Hewitt et al, 2016). However, these approaches are still scarce in the literature and are mostly focused on the combined effects of temperature with other factors (e.g.…”

“…However, the efficiency of these mechanisms in terms of water and ionic balance under sequential exposure to both stressors, as frequently occurs in nature, has not been studied in saline aquatic insects. If the stressors occur close enough in time, so that exposure to the second stressor takes place while the physiological response to the first stressor is still being mounted, interactive effects that result in cross-tolerance or cross-susceptibility are likely to occur (Gunderson et al, 2016).…”

Growth and lipid profiles of the Antarctic snow microalga Chlamydomonas sp. In response to changes in temperature, photoperiod, salinity and substrate

“…The effects of short acclimation to a wide span of temperatures on photosynthetic electron transfer, lipid and fatty acid composition in the snow alga have been measured on Chlamydomonas cf. nivalis (Lukes et al 2014), Further, the response to a combination of stressors such as high ultra violet (UV) radiation and enhanced temperatures has been recently measured for marine Antarctic and sub-Antarctic microalgae (Cruces et al 2012) as well as for other marine organisms (Gunderson et al 2016).…”

Assessing Marine Protected Areas Effectiveness: A Case Study with the Tobago Cays Marine Park

“…These impacts have over time brought attention to the need for better marine management and conservation measures [7] [8] [9] [10]. Effective marine management is the required mechanism to ensure the sustainable use of the ocean's resources and to develop conservation strategies.…”