Effect of temperature on predation in a warming ocean

Temperature is one of the most critical abiotic factors, influencing biological processes at every level, from cells to individuals, communities, and ecosystems. For ectotherms, which have limited control over their body temperature, environmental temperature can directly affect physiological activity, behavior, and ecological interactions. Predation is a key factor in determining the abundance and distribution of species and is crucial in structuring natural communities. Since most organisms in the ocean are ectotherms, temperature regulates predation across marine habitats. As the ocean warms at an unprecedented rate, understanding the impact of temperature on marine habitats has become one of the most urgent scientific questions. The Galápagos Archipelago holds significant ecological, economic, and cultural value. It has high endemicity, supports large fisheries, and has played a fundamental role in our understanding of natural history. Its unique oceanographic conditions create a dynamic system with substantial variations in water temperature. As a result, the Galápagos serves as an ideal natural laboratory for studying the role of temperature in regulating ecological interactions.This dissertation employs multiple approaches to better understand the relationship between temperature and predation within marine communities by integrating a systematic review and meta-analysis, physiological assays, and laboratory and field experiments.In Chapter 1, I reviewed the effects of ocean warming and acidification on predation and herbivory in marine organisms. In Chapter 2, I measure asymmetries in thermal performance across intertidal predators and their prey. Chapter 3 explores the effects of temperature across traits and predation in the lab and the field, using a whelk and its primary prey, a barnacle, as a model system. In Chapter 4, I investigate how starvation influences thermal performance. Finally, in Chapter 5, I measure fish predation on reefs across a temporal and spatial temperature gradient.This research highlights how temperature influence predation in intertidal and subtidal habitats in the Galápagos. Furthermore, it underscores the vital role of temperature in shaping ecological interactions, which are fundamental to structure of marine communities and determine ecosystem functioning. Understanding these temperature-driven dynamics is essential for predicting the future of marine community structure and ecosystem functioning in a changing climate.