2019 Warren McLeod Fellowship Winners
Congratulations to the following students who were chosen to receive the prestigious Warren McLeod Fellowship awards!
Emily Chua – Annual Award Winner
Nicola Kriefall – Summer Award Winner
Tina Barbasch – Summer Award Winner
Robin Francis – Summer Award Winner
James Fifer – Summer Award Winner
Claudia Mazur – Summer Award Winner
Severe tropical cyclones, among many other climate change stressors, currently threaten reef-building corals in the Caribbean Sea. Storms can damage reefs asymmetrically, with reef zones exposed to distinct degrees of physical damage, turbidity, and storm-water runoff. Mounting evidence suggests that algal & bacterial communities hosted by corals play important roles in coping with environmental stressors and can differ significantly across reef zones. However, almost nothing is known regarding the impact of tropical storms on coral-hosted communities, especially in the context of these divergent reef environments. In my current research, I aim to elucidate whether coral-hosted communities from divergent reef zones in the Florida Keys were differentially impacted by Hurricane Irma in 2017. Tissue samples from two coral species (Siderastrea siderea and S. radians) at three paired inshore-offshore transects were collected prior to, directly after, and in the years following Hurricane Irma. By using 16S & ITS2 metabarcoding to identify the members of the bacterial and algal communities present in each coral sample, I will be able to detect shifts in community compositions and whether these shifts differed across reef zones. This summer, I will conduct my final sampling collection, mentor an undergraduate student in final sequencing library preparation and bioinformatic analyses of the sequencing data, and begin manuscript preparation. This study will reveal whether microorganismal communities underpinning coral health appear altered, resistant, or resilient in the face of severe storm disturbance events projected to intensify over the coming century.
Conflict is a pervasive feature of animal societies. Conflicts arise whenever the interests of interacting individuals are not wholly aligned, yet many social interactions require individuals to reach some compromise. Parental care is a classic example of an interaction that is rife with conflict yet requires cooperation because both parents benefit from shifting the burden of care to the other. The outcome of conflict between parents has been modeled using economic game theory models, which assume that individuals act in their best interest but that their optimal behavior depends on how others behave. Studying how conflict among caring parents is resolved is critical to understanding why animals, including humans, form such alliances.
The goal of my research is to test plausible alternative hypotheses for the factors that govern how parents negotiate the amount of care to provide to their offspring, and create a more general framework for understanding conflict resolution. To accomplish this goal, I will build on existing empirical and theoretical work to test alternative hypotheses for how parents negotiate care utilizing a tractable study system: the clown anemonefish. Experiments will be conducted in a natural population of anemonefish (Amphiprion percula) in Papua New Guinea. The anemonefish system allows tests of alternative hypotheses simultaneously, where previous studies have only tested them in isolation. Furthermore, the majority of negotiation studies have been conducted in birds, so developing A. percula will function to test the generality of theoretical predictions. In sum, my research uses a tractable study species together with a rigorous alternative hypothesis testing approach to determine the factors that influence the outcome of negotiations. This research will help to create a more general framework for studying conflict resolution and potentially transform our understanding of negotiations over offspring care.
My research is concerned with understanding fish population persistence through the framework of marine metapopulation dynamics from the starting point of reproductive output. Metapopulation ecology provides a framework in which to parameterize how populations persist: a population must be able to self-replicate, or be connected to other population to re-populate. These criteria are first and foremost controlled by per capita rate of reproduction. My research focuses on (1) determinants of an individual’s reproductive success, (2) the determinants of interdependence of a population’s total reproductive success, and (3) the informative determinants of reproductive success for many taxa of fishes. I aim to address these objectives by performing empirical studies of two emerging model systems: the line-snout goby Elacatinus lori and the clown anemonefish Amphiprion percula.
Individual reproductive success is often highly variable, due to various influences. Focusing on a single model system, E. lori, I aim to measure various characteristics at multiple levels within the system to determine what best predicts determinants of reproductive success.
Collective reproductive output between populations is also often variable. I aim to determine the spatial and temporal determinants of patch-wise independence (i.e., spatial-autocorrelation) in both a continuous reef system (E. lori) and a fragmented reef system (A. percula). This analysis will demonstrate if fish reproductive output may be correlated in space and/or time and how this determines the total number of independent patches within a metapopulation network.
In summary, the objective of my dissertation is to test assumptions regarding reproductive output of populations, the spatial-temporal independence of populations, and investigate the relationship between multiple determinates of reproductive success and realized reproductive output for fishes in general. It is my goal to produce results that will enhance our understanding of reef fish metapopulation dynamics and inform reserve design.
There is a recent trend of species’ range shifts as a consequence of climate change-related stressors. This includes a consistent poleward shift in response to warming. These expanded populations can create socio-political tensions between states and even across countries as commercially relevant species, and those species that provide habitats for them, modify their ranges without respect for political boundaries. Range expansion also alters the community structure of other species already native to the expansion front and can lead to reduced genetic diversity of the expanding species, in turn potentially limiting the ability for the species to adapt and persist in their new environment. By using population genomic tools we can provide insight into the ecological and evolutionary processes that govern an expanding population. My goal is to address the consequence of range expansion in coral populations. Given corals are major habitat builders, a range shift for these organisms can have cascading impacts on dependent species, populations and ecosystems. Their sensitivity to temperature and rapid dispersal capabilities mark corals as candidates for range expansion under predicted future warming. Additionally, the survival of coral species under a changing climate might depend on their ability to successfully shift their range. I am studying the important reef-building coral Acropora hyacinthus in Japan, where populations have shown recent northward expansion. I will investigate changes in genetic diversity and putative genes targeted by selection in these expanding coral populations to shed light on the evolutionary processes underlying successful coral expansion.
This summer I will conduct my field work in an Fe rich, shallow, temperate, estuary (Waquoit Bay, MA) to explore these questions further. I will collect sediment samples along a gradient of high to low concentrations of Fe. I will use these samples to (1) quantify seasonal rates of sediment Fe2+ oxidation, denitrification and DNRA, (2) determine how concentrations of Fe2+ and NO3- alter rates of denitrification and DNRA and (3) characterize the potentially active sediment microbial community. Research regarding the coupling of Fe and N cycling is critical to assessing coastal N budgets in similar coastal environments experiencing hypoxic/anoxic conditions. Furthermore, by understanding the factors that influence processes such as denitrification and DNRA, we can better predict the fate of nutrients and productivity in coastal sediments. Ultimately, my research will contribute to our understanding of coastal marine nutrient cycling while protecting our dynamic coasts.