UC Irvine

Climate is changing at unprecedented rates and marine species worldwide will need to adapt, acclimate, or shift their ranges to persist. The majority of marine organisms have complex life cycles, in which developmental stages differ in morphology, physiology, habitat, and environmental tolerances. To better predict the impacts of climate change, we must understand how each stage responds and copes with ocean warming – especially early life stages that are most vulnerable to environmental stress. In Chapter 1, I investigate the effects of environmental conditions during development on larval survival in Mexacanthina lugubris, a whelk species shifting its range northward along the west coast of the United States in response to climate change. We found no difference in reproductive output or larval survival across shore heights, suggesting egg-laying behavior may buffer developing stages from thermal stress. In Chapter 2, I test the influence of parental environments on offspring thermal tolerances in an important foundation species, the California mussel (Mytilus californianus). We observed parental effects across one generation, where adult mussels exposed to warmer habitats yielded less tolerant offspring. We also found indicators of trade-offs in energy investment where mussels in low stress environments had higher reproductive condition and larger egg diameters. Finally, in Chapter 3, I explore the critical time windows that influence transgenerational plasticity across generations in marine invertebrates using a meta-analysis. This meta-analysis revealed that the outcomes of transgenerational plasticity vary by trait type, taxonomical groups, and life history traits. I found that gametogenesis is a key window in a parent’s life for experiencing an environmental stressor to result in transgenerational plasticity. Together these results elucidate some of the factors and coping mechanisms that will determine the persistence of marine species under climate change. My dissertation highlights the importance of understanding the impact of climate change across life stages and generations when predicting the survival of marine invertebrates.