Guille Garcia Gomez

I began my PhD in March 2018, working with David Atkinson, Leonie Robinson and Andrew Hirst. I briefly summarise my research below.

Metabolic rate is a measure of the rate at which energy is used, and it is highly related to body size. The quantitative relationship between metabolic rate and body size (often termed scaling) has been a central topic in physiology and ecology for many decades, and explaining its magnitude and variability remains a considerable challenge. Some species show a near constant rate of energy use per gram as they grow, while others show a marked reduction as the body enlarges. Temperature is also a strong driver of biological rates in ectotherms, as higher temperatures commonly lead to greater metabolic rates, and reduced energy use per gram as body size increases (decreasing the mass-scaling exponent). It has been hypothesised that this reduction during growth is caused by a shift from volume-related to surface area-limited processes.

 

My PhD presents an alternative hypothesis to explain the observed reduction in mass-scaling exponents with increasing temperature, based on how costs of growth change as an organism gets hotter and bigger. My research uses quantitative models to test whether these mass-scaling exponents correlate negatively with rapid growth, as usually occurs when growth declines towards adulthood at warm temperatures. Considering the costs of growth may also help to explain stark differences in metabolic scaling between pelagic and benthic animals, and between life histories. I'm using a range of techniques to address these questions, including intra-specific meta-analyses of fish and aquatic invertebrates, as well as experiments with crustaceans.

Aquatic ecosystems have a profound impact on humankind and the biosphere, and can provide critical insight into biological questions. Using marine and freshwater organisms our research aims to mechanistically understand and predict rules of physiology and ecology. We examine physiology, vital rates and ocean biogeochemistry, including assessing the impacts of climate change. In our work we use diverse approaches including meta-analysis, experimentation, fieldwork and modelling.