Corals are biogenic habitat and host a variety of symbionts. Some of these symbionts provide benefits for the coral, while others are harmful. I’m interested in how these positive and negative interactions create spatial patterns across a seascape. These dynamics depend on factors such as settlement patterns, mortality, and the strength and direction of the interaction.

To address these questions, I use a combination of field and modeling approaches. For example, in Hamman 2018 (Coral Reefs), I documented the spatial distributions of two corallivorous snails and explored the causes and consequences of those distributions. In Hamman et al. 2018 (Theoretical Ecology), I led a modeling effort that demonstrated how the configuration of habitat patches (e.g. corals) could generate similar levels of heterogeneity in occupant numbers as variation in habitat quality.

I'm currently working on models of spatial coral dynamics that explicitly include these interactions as part of an NSF grant. Most of the work with this project is currently focused on the modeling work, and there are several aspects to this modeling where students interested in mathematical modeling or simulations in R could get involved, especially related to applications to conservation and restoration. I am also in the process of exploring the relevance of these models to systems local to Southern Maryland, such as saltmarshes and oyster reefs.

Corals are damaged by predators that create different scars of different sizes, shapes, and spatial patterns. It’s advantageous for the coral to heal quickly, and as a result, neighboring polyps often contribute resources to heal damage. I’m interested in how corals (and other colonial or modular organisms) respond to different patterns of damage. For example, if a coral predator creates clustered damage, is that better or worse for scar healing? Does it affect the health of the colony? What are the long-term effects of that pattern?

To address these questions, I use a combination of field experiments and stochastic growth models. Using field surveys and experiments, I’ve demonstrated how scars close to one another heal more slowly than scars far apart, and that these effects can affect the morphology of the coral (Hamman 2019, Oecologia). Based on these results, I’m now interested in expanding that work in several ways, including expanding to additional modular organisms, developing stochastic growth models that can help predict the effects of various stressors on coral morphology, and studying how those changes in morphology might affect long-term reef health. At SMCM, students have already piloted studies with Galaxea fascicularis in our wet lab, and there will continue to be opportunities for students to continue this work as directed research or SMPs.

These projects overlap with my teaching interests. I'm on the steering committee of the UBE-RCN BioGraphI, which is developing lessons for undergraduate biology classes that combine graphical activities with scientist interviews. As a member of the steering committee,I'm a member of teams assessing students and faculty that use these lessons to determine how they meet our learning objectives. I'm also working with a group of educators investigating how these types of activities affect the sense of belonging, science identity, and quantitative skills of the students.