Motivation for our research
Foundational research is the bedrock of innovation, driving new technologies and solutions to society’s greatest challenges. Our lab’s research seeks to accelerate ecosystem recovery, enhance resilience to multiple stressors, and sustain the vital benefits that ecosystems provide for people and nature. If we are to interpret how our ocean is responding to the greatest challenges of our time (e.g., climate change, biodiversity loss, overfishing), an integrative understanding of the mechanisms that determine the resilience of ecosystems is needed. As such, our research aims to advance knowledge surrounding how species interactions and environmental change organize the structure, functioning, and stability of nearshore marine ecosystems.
Overview
The Nearshore Ecology Research Group at UC Santa Cruz aims to deepen our understanding of how environmental and ecological contexts influence ecosystem resilience. Our operational definition of resilience builds on C.S. Holling’s framework – it includes both a system's capacity to persist through perturbations without functional change, and its ability to recover to its prior state once environmental conditions stabilize (i.e., resilience = persistence + recovery). However, under directional environmental change, systems can transform, and ecologists need to understand and predict how and when systems will shift. To advance our understanding of resilience, we develop questions informed by foundational ecology and our own field observations. We combine observational studies and long-term monitoring to form testable hypotheses on the maintenance of biological organization, and how ecosystems respond to environmental change. We also use field experiments, along with quantitative modeling, meta-analytic methods, and data science to build broad frameworks that explain the drivers of community and ecosystem dynamics. Ultimately, our research questions are guided by three intersecting vignettes in coastal ecosystems: foundational ecology, human-driven challenges, and conservation impact.
Core research themes
Recovery and persistence are two fundamental components of resilience – the central focus of the lab. Within these two general lines of research, we are interested in developing a mechanistic understanding of processing such as:
Trait mediated (indirect and behavioral) vs. direct (consumptive) responses. In kelp forest ecosystems, our research has shown that changes in the grazing behavior of purple sea urchins can drive pronounced ecosystem shifts (Smith & Tinker 2022), but that predator behavioral responses to prey condition can explain patterns of patch persistence (Smith et al. 2021). We are expanding on this body of work through observational and experimental studies in kelp forests to understand the mechanisms that drive behavioral transitions in herbivores. We are also interested in the relative strength of behavioral responses versus demographic drivers of transitions, such as herbivore recruitment.
Mechanisms that determine the ‘keystoneness’ of predators and the relative strength of top-down vs. bottom-up community regulation. The relative influence of predation and primary production in nearshore marine ecosystems is context-dependent and can rapidly shift in response to climate perturbations, such as marine heatwaves. Our research has shown that the loss keystone predators can impart changes beyond the habitats they occupy, extending across ecosystem boundaries (Smith et al. 2025). We are interested in understanding the mechanisms that determine the relative strength of top-down vs. bottom-up forcing, and how these processes contribute to community and ecosystem persistence and transition dynamics.
Persistence through resource mosaics and multi-stressor environments. Ecosystem persistence is often mediated by heterogeneity in resources (e.g., food subsidies, shelter, microclimate refugia) and interacting stressors (Smith et al. 2024). We build mechanistic models that integrate these factors to understand when ecosystems resist transformation.
Regulatory protection for ecosystem conservation. We use long-term monitoring, data science, and ecological syntheses to assess the impacts of climate change on nearshore ecosystems and to evaluate the effectiveness of regulatory protections in conserving biodiversity and ecosystem functioning (e.g., Smith et al. 2024, Smith et al. 2025). California’s large network of marine protected areas has generated a leading global dataset for studying these impacts. We synthesize decades of data collected through the state’s long-term MPA monitoring enterprise to identify mechanisms of ecosystem resilience and inform adaptive management strategies.