Responses to Temperature and Hypoxia as Interacting Stressors in Fish: Implications for Adaptation to Environmental Change

Abstract

Anthropogenic environmental change is exposing animals to changes in a complex array of interacting stressors and is already having important effects on the distribution and abundance of species. However, despite extensive examination of the effects of stressors in isolation, knowledge of the effects of stressors in combination is limited. This lack of information makes predicting the responses of organisms to anthropogenic environmental change challenging. Here, we focus on the effects of temperature and hypoxia as interacting stressors in fishes. A review of the available evidence suggests that temperature and hypoxia act synergistically such that small shifts in one stressor could result in large effects on organismal performance when a fish is exposed to the 2 stressors in combination. Although these stressors pose substantial challenges for fish, there also is substantial intraspecific variation in tolerance to these stressors that could act as the raw material for the evolution of improved tolerance. However, the potential for adaptive change is, in part, dependent on the nature of the correlations among traits associated with tolerance. For example, negative genetic correlations (or trade-offs) between tolerances to temperature and hypoxia could limit the potential for adaptation to the combined stressors, while positive genetic correlations might be of benefit. The limited data currently available suggest that tolerances to hypoxia and to high-temperature may be positively correlated in some species of fish, suggesting the possibility for adaptive evolution in these traits in response to anthropogenic environmental change.

Warm acclimation improves hypoxia tolerance in Fundulus heteroclitus

“…Understanding the impacts of multiple interacting stressors is critical for predicting how animals will respond to human-induced climate change (Rudd, 2014;Todgham and Stillman, 2013;McBryan et al, 2013). However, most studies of stressors relevant to climate change focus on the effects of single stressors in isolation, even though it is known that stressors may act quite differently when experienced in combination (Wernberg et al, 2012;Crain et al, 2008).…”

Higher temperature exacerbates the impact of sediments on embryo performances in a salmonid

“…Sediments may clog up substrate, rendering the environment hypoxic around the egg [9]. Effects of temperature-hypoxia interactions have often been demonstrated in fishes (review in [10]), yet most studies assessed such effects on metabolic rates solely, and none addressed their impact on early life-history traits (LHT) or the interaction between temperature and sediment-induced hypoxia.…”

Deepwater Horizon Oil Spill as a Case Study for Interdisciplinary Cooperation within Developmental Biology, Environmental Sciences and Physiology

“…Indeed, even intraspecific differences in the response to environmental stressors exist, and likely influence the response to crude oil [31]. Killifish populations on the East Coast of the US have variable responses to thermal and salinity stress [32] [33], and some have developed a resistance to PAH teratogenicity, and toxicity in adults [34] [35]. RECOVER physiologists and collaborators in the ecological and molecular sciences are using populations of Fundulus grandis found along the Gulf of Mexico coast to better understand how a species of fish may react differently to PAH exposure from oil based on their respective exposure histories.…”