Meta‐analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming

Abstract

Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta-analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life-history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single-stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible.

Pathogenic challenge reveals immune trade-off in mussels exposed to reduced seawater pH and increased temperature

“…This study is therefore consistent with previous research that highlighted the importance of measuring the impact of environmental stressors in combination (Harvey et al, 2013;Kroeker et al, 2013;Wood et al, 2010), as doing so indicates that organisms may be more vulnerable to climate change than suggested by single stressor studies.…”

Interactions among ecosystem stressors and their importance in conservation

“…survival, growth, abundance, behaviour e.g. species diversity, biomass, total primary production additive antagonistic Crain et al [15] Darling & Côté [16] Dieleman et al [32] Gruner et al [26] Harvey et al [47] Przelawski et al [22] Wu et al [31] Stephens et al [29] Wahl et al [33] Jackson [27] Figure 4. Links between various categories of responses to multiple stressors and the types of interactions occurring between these stressors.…”

Exploring local adaptation and the ocean acidification seascape – studies in the California Current Large Marine Ecosystem

“…While capacity for resolving mean state vs. variability impacts and interactions between multiple stressors remains a limiting factor in the field, development of new experimental systems (Bockmon et al, 2013) can enable experimental treatments that mimic exposure regimes that organisms are observed and forecasted to face in situ. Such advances will be crucial to making more robust forecasts regarding the ecological consequences of future ocean change (Boyd, 2011;Harvey et al, 2013). Finally, as the complexity of this issue unfolds it will require that scientists engage more actively with policy makers, conservation biologists, and managers of critical marine ecosystems (Dawson et al, 2011;Ibáñez et al, 2013;Kelly et al, 2011).…”