Current Research and Research Interests

M.S. Thesis:

Variation in population dynamics between two tropical fucoids in a patchy reef environment and their differential impacts on corals

Backreef habitats in Moorea, French Polynesia are dominated by two macroalgal species; Sargassum mangarevense and Turbinaria ornata. Growth, competition and recruitment are three ecological processes driving the demography of their populations. Biomass and density vary temporally via seasonal maturation and subsequent senescence of upright branches.  Although T. ornata retains a higher abundance than S. mangarevense throughout the year, peak abundance for both species occurs in the austral winter and is inversely related to maturity.  Both T. ornata and S. mangarevense utilize fragmentation and localized dispersal for proliferation. The presence of holdfasts that develop reproductive upright branches may promote recruitment near the adult resulting in high density patches of either or both species.  Probable differences in recruitment and growth between these two species may provide a mechanism for the current dominance of T. ornata within the backreef habitat.  In past years, during both austral summer and winter, there has been a healthy population of S. mangarevense. Changes in the dominant algal species within these reef communities may be based on the success of annual recruitment, the holding of space by perennial holdfasts and/or the growth of those holdfasts and upright branches relative to other species. These questions will be addressed by monitoring individuals, clearing plots of existing algae to observe recruitment and growth, measuring the growth of holdfasts and thalli, and manipulating individuals within transplants. Understanding the seasonal variation of dominant primary producers may provide further insight to the functioning of coral reef ecosystems.