Research

What motivates my research?

We (humans) depend on natural ecosystems for survival, because these systems fulfill our need for food and shelter. For example, it is estimated that 1 billion people depend on fish as their primary protein source, and most of these fish are caught from natural ecosystems. However, in addition to being dependent on natural ecosystems, humans alter these systems and reduce the essential benefits they provide us.  This means that as our global population continues to grow, our survival will increasingly depend on our ability to maintain natural ecosystems. This reality has motivated me and many others to explore what determines ecosystem resilience, which is the ability of an ecosystem to remain in its natural state by resisting or quickly recovering from changes and disturbances, including those driven by humans.  So, the big (if not the biggest) question of our time is:

What determines ecosystem resilience?

Our ability to provide answers to this question and, just as importantly, to make the world aware of these answers will determine the future of our species (including our children, grandchildren, great grandchildren, and so on). Fortunately, there is a simple, objective process that we can use to answer this question, and it is called science. This question motivates my work as a scientist.

My research to date spans two core questions that aim to better understand ecosystem resilience from different angles:

1. How can environmental stressors affect organisms that support the diversity and function of the greater community?

Organisms thrive under a particular set of environmental conditions. While people may thrive in fair weather and a booming economy, organisms in nature may thrive within a particular range of factors, like temperature, salinity, pH or soil moisture. However, as the global climate changes and as human populations continue to grow, local environments can shift rapidly. Environmental changes, such as increased temperature or nutrient pollution, can harm organisms, and we call the factors associated with these changes “environmental stressors”. Therefore, to support human populations with vital ecosystem services, we must protect ecosystems from stressor-induced degradation. However, environmental stressor effects are challenging to understand and thus manage for, in part, because 1) a given stressor can often occur over a wide range of levels, and 2) multiple environmental stressors can co-occur and affect one another, yielding combined effects that are difficult to predict. Therefore, my colleagues and I study how different levels and combinations of environmental stressors affect key organisms, so that we, as a global society, can better understand and protect against ecosystem degradation.

2. What factors modify species interactions that promote ecosystem resilience?

Species interactions can drive key ecological processes and services. For example, herbivorous reef fish eat algae, and this promotes both coral dominance of the reef environment and the services that coral reefs support (e.g., fisheries, coastal protection). However, this important fish-algae relationship can be modified by other factors, like snorkelers scaring herbivorous reef fish and, in doing so, lowering their feeding rate on algae. Snorkelers are just one example of a variety of natural and anthropogenic (generated from humans) factors that can modify the way that species interact with one another. These modifications of species interactions are referred to as “higher order interactions” and, as in the previous example, can weaken ecosystem resilience (when unchecked, algae can come to dominate the reef). As scientists, a fundamental way we try to understand relationships like higher order interactions is with experiments conducted in the field (i.e., in nature) or in the laboratory. Yet, due to technological constraints, experiments traditionally provide a narrow window of observation across space and time, and this limits our ability to understand important relationships, especially those that involve processes that occur at scales that greatly exceed our window of observation. For example, in tropical coral reefs, we traditionally study the interactions and processes associated with roving herbivorous reef fish at spatial scales (e.g., 1 m2) that are many orders of magnitude smaller than the movement range of these animals (>10,000 m2), which can thus be affected by a vast environment that is not considered in the study. Therefore, by integrating concepts from classic ecological theory with tools in geography, mathematics, computer science and videography, my colleagues and I strive to overcome traditional observational constraints to explore higher order interactions from a fresh perspective. With this work, we hope to unveil important insights at the intersection of community, behavioral and spatial ecology to better understand how ecosystems work and what promotes their resilience.